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2005

Case Studies forSIPROTEC Protection Relays andPower Quality

http://siemens-russia.com/

Editorial

Case Studies forProtective Relaying and Power Quality

Dear reader,

this brochure describes a selection of projects which apply SIPROTEC relays and

SIMEAS power quality devices in the power system and machine protection

field.

SIPROTEC and SIMEAS have firmly established themselves on the market as a

standard for numerical protective relaying and power quality devices respec-

tively. No matter if you need to protect transmission lines, transformers,

motors, generators, substations or busbars, SIPROTEC relays will always

provide an optimized and efficient solution, which in association with SIMEAS

power quality devices will provide you reliability and control beyond your

expectations.

The case studies are focused on the following topics:

� The variety of functions in the protection relays often allow “one bay one unit

concept” for protection and bay control for each bay.

� The uncomplicated logic functions, with the CFC editor, greatly simplify

system configuration

� Flexible and easy to retrofit communication modules mean that SIPROTEC

relays can be easily linked to your existing control and protection equipment.

� Power system disturbances (or fluctuations in the quality of supply) are of

course highly undesirable. SIMEAS digital power quality products can quickly

and accurately record, indicate and analyze faults and measurements.

I invite you to read through the case studies, and learn about the versatility and

flexibility of SIPROTEC relays and SIMEAS Power Quality solutions. Not only

savings in operation and maintenance, but also simplified engineering, less com-

plexity, and long-term reliability and expandability can make you one of the

winners in tomorrow’s marketplace.

Paulo Ricardo Stark

Vice President

Power Transmission and Distribution – Energy Automation

Protection Systems division

“We ensure reliability in energy supply!”


Contents

Power System Protection

SIPROTEC 4 Line Differential Protection forFive Line Ends and Distance Protection 3

SIPROTEC 4 Enables Maximum Supply Securityin the Petrochemical Industry 7

Unipolar Disconnector Control in theKazakhstan Project 11

SIPROTEC 7SA6 Distance Protection Relay withInter-Relay Communication 15

SIPROTEC Protection Systems of the LatestGeneration in Argentina 17

Intelligent Protection System Spare LEW ExpensivePower System Expansion 21

Protection Systems Deutsche Steinkohle AGCan Depend on 25

SIPROTEC 7SA6 with Auto-Reclosure on Mixed Lines 29

Potential Savings through New Concepts inProtective Relaying 33

Differential Protection over Conventional PilotWires at the Varel Paper and Board Factory 37

SIPROTEC 7UT635 Differential Protection forAllgäuer Überlandwerke 41

Satellite and Power Line Carriers TransmitProtection Data in Peru 45

Automatic Switchover for Incoming Feeders 49

Malta Power Plant System Solution withDynamic Load Shedding 51

Generator Protection

SIPROTEC 4 Ensures Safe Operation of theThree Georges Hydroelectric Power Plant 53

Protection and Control as a Unified System forHydroelectric Power Plants of Energie AGOberösterreich 57

Power Quality

Quality Recording in Static VAr Compensators SVC 61

Fault Recording for HVDC Transmission Systems 63

Fault Recorder System at CERN 67

Fault Analysis in Zurich Using Fault Recorders andProtection Relays 71

Fault and Power Quality Recording atPfalzwerke AG 75

Monitoring the Data Center of the DEVKInsurance Company in Cologne 79

Aera-Wide Fault Recording UsingState-of-the-Art Technology 81

The Fault and Power Quality Recording Systemat CFE 85

Business Processes

The Energy Business with Electronic Processes(e-procure) 89

Case Studiesfor SIPROTEC Protection Relaysand Power Quality2005

© Siemens AG 2005


Siemens PTD EA · Case Studies · 2005 3


SIPROTEC 4 line differential protection for five lineends and distance protection

� The companyProviding area-wide power – and thus a basis foreconomic growth - is the job of the power supplycompany. This is why Vietnam’s national powercompany Electricity of Vietnam (EVN) is con-stantly expanding its power supply system. Apower plant complex is currently being built inthe Phu My industrial park. Upon its completion,it will supply up to 3600 MW of power to the500 kV and 220 kV transmission systems.

Siemens Power Generation (PG) is part of theproject. “Phu My 3”, currently Vietnam’s largestprivate GUD power plant and located about70 km southeast of Ho Chi Minh City, was com-missioned by PG. Three power station units sup-ply 720 MW to the extra-high voltage system.

� The starting situationThe customer wanted a fully redundant protec-tion system, plus a cost-effective solution for thelong-distance transmission of trip commands tocircuit-breakers at remote line ends. This requiresthat trip commands from the busbar and breakerfailure protection relays be transmitted from the500 kV station to the circuit- breakers upstreamfrom the power station units via binary inputs onthe protection relays. In the opposite direction,TRIP commands must be transmitted from theprotection relay of the power station unit trans-formers and from the breaker failure protection tothe circuit-breakers in the 500 kV station. For rea-sons of cost, no circuit-breakers were installed onthe 500 kV side of the generator transformers. Forprotection purposes, optical fibers were integratedinto the overhead earth (ground) wire of the500 kV line.

� The conceptFollowing an analysis phase, Siemens Power Auto-mation Vienna presented a comprehensive pro-tection system with the following components(see Fig. 4):

� One 7SD523 line differential protection relayand one 7SA522 distance protection relay foreach of the two ends of overhead line 11. Bothrelay types are equipped with a fiber-optic con-nection.

With Maximum Flexibility,Ready for Anything

Fig. 1 Industrial area Phu My

� For the three ends of the protected zone, com-prising overhead line 12 and the outgoing cir-cuits of generator transformers T2 and T3,Siemens recommended three 7SD523 line dif-ferential protection relays and three 7SA522 dis-tance protection relays. One optical ring isprovided per protection relay for a dual redun-dant communication link.

SIPROTEC 4 line protection relays protect thepower station’s two major 500 kV outgoing cables.With a total of ten 7SD523 and 7SA522 line differ-ential and distance protection relays, SiemensPower Automation (PTD PA) has designed astate-of-the-art, flexible protection system. More-over, SIPROTEC 4 line protection relays can beinterconnected via optical rings, meaning they canimmediately detect a communication link failure.In a matter of milliseconds, the protection relaysswitch from the failed ring connection to a chainconnection. Neither the protection functions norlong-distance signal transmission is affected bythis fault, which is extremely important –especially when transmitting long-distance tripcommands.

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Siemens PTD EA · Case Studies · 20054

Another innovative, detailed solution involves in-dependent communication links for the long-dis-tance signal paths used for transmitting tripcommands. Transmission is via both the 7SD523main protection relay and the 7SA522 backupprotection relay.

� The special advantagesFlexible, secure and fast thanks topre-parameterization with DIGSI

The SIPROTEC 4 protection relays can bequickly and reliably adapted, based on the pri-mary system’s degree of completion. The pa-rameter sets can already be prepared during theproject planning phase. All the Siemens protec-tion relays will be configured, parameterized,tested and safely commissioned with the aid ofthe DIGSI universal operating program.

� From practical experiencePower transmission without a stationThe flexibility of the SIPROTEC product rangewas of particular advantage in this project, makingmany things possible that would otherwise havebeen impossible. When the day appointed for thepower station’s commissioning finally arrived, forexample, construction of the 500 kV station andnew 500 kV transmission lines for transportingpower to the metropolitan areas had not yet beencompleted. Consequently, our engineers decidedto build a provisional structure next to the site ofthe new 500 kV station. Two transformers, eachwith 450 MVA transmission power, were tempo-rarily installed to feed power from the Phu My 3plant to the 220 kV power system via a nearbysubstation.

Power station test run under extreme conditionsBut how can you hand over a power station to thecustomer unless you first test it at nominal load?The challenge: Transmit 570 MVA power frompower station units 2 and 3 via 500 kV line 12 andthe underdimensioned 450 MVA transformer.The solution: Connect the two 500 kV lines inparallel during the Phu My 3 test phase. Thismade it possible to use the standby capacity of thesecond 450 MVA transformer connected to line 11.However, if a short-circuit occurred while testingthe overall system – comprising three generatortransformers, two 500 kV lines, the two provi-sional transformers and connecting cables on the220 kV side – the power could be shut down onlyby an emergency trip. It was therefore decidedthat the parallel connection of the two 500 kVlines would be dismantled once the test phase wasover. Until the new 500 kV station is completed,the power station will be operated so as to preventthe provisional 450 MVA transformer connectedto line 12 from being overloaded.

SIPROTEC 7SD523 and 7SA522 temporarily protectthe transmission system with 5 line endsSiemens Power Automation gladly accepted thechallenge of protecting this 5-end system. Theplanning, setup and testing of the protection cubi-cles had already been completed when the ownerissued a new request. In this case, the flexibility ofthe SIPROTEC relays permitted a fast and simpleconversion to a protection system for five lineends.

Fig. 3 Main and backup protection 7SD52 and 7SA522

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Fig. 2 Easy setting with DIGSI program

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The 7SD523 differential protection relays for mul-tiple line ends can be connected to the 2- to 6-endprotection system and parameterized at any timeat no additional cost. The 7SA522 distance protec-tion relays, in combinations of one two-end andone three-end optical link, can also be connectedto the 5-end protection system via copper-wireconnections and conventional contacts.

Within a very short time, the protection solutionwas ready for presentation to the customer andthe protection system could be adapted to the pri-mary system’s modified topology in three phasesat no substantial additional cost:

� Phase 1: Protection of the 5-end transmissionsystem during the power station test phase.

� Phase 2: Protection of the 2-end and 3-endtransmission systems with long-distance signaltransmission of commands from the protectionsystem of the provisionally installed 500 kV/220 kV transformers and provisional220 kV circuit.

� Phase 3: Protection of the final 2-end and 3-endtransmission systems.

Fig. 4 Concept for the final scheme




�ConclusionThanks to the diversity of SIPROTEC relays andour engineers’ expertise, we were able to signifi-cantly reduce the commissioning time for thefinished power station, despite the fact that theinfrastructure was not yet fully expanded. Viet-nam’s energy network was reinforced, providinga stronger basis for their booming economy.

�PlusThe SIPROTEC relays have meanwhile been con-verted to the parameter set for operating phase 2.The power station was successfully tested and theparallel connection of the two transmission lineswas dismantled. The protection commands fromthe SIPROTEC relays will now be transmitted tothe 220 kV station until the 500 kV system hasbeen completed.

Fig. 5 Protection concept for the power station test phase




SIPROTEC 4 enables maximum supply security inthe petrochemical industry

� The companyBP Cologne, headquartered in Worringen, a sub-urb of Cologne, is a wholly-owned subsidiary ofDeutsche BP AG in Hamburg. As the fifth largestpetrochemical location in western Europe, BP Co-logne is an important supplier of raw material tothe chemical industry, with about 1,900 employ-ees. Each year BP Cologne derives millions of tonsof chemical raw materials from the light gasolineproduced by refineries during the refining of pe-troleum. The chemical industry uses these materi-als as basic components for the production ofplastics and fibers. The BP Cologne plant relies onthe northwest European ethylene pipeline to sup-ply chemical companies. Economic and reliableoperation of the facility depends on a secure sup-ply of electrical power. BP Cologne has a powerrequirement of approx. 160 MW.

� The starting situationThe supply of raw materials and the shipment ofrefined chemical products are inseparably linkedto the actual chemical process. In the past, an en-closed single-busbar switchgear supplied power tothe light gasoline tank farm and the compressorstations. Expanded production, higher supply se-curity, and reduced personnel resources for opera-tion and maintenance all combined to increase thedemands placed on the switchgear and its primaryand secondary systems. Failures in these areashave a direct impact on production, causing con-siderable damage and high costs. For this reason, aswitchgear was built at a central point to guaran-tee a reliable supply of light petroleum for thecracker production and also the output of ethyl-ene (over 1 million metric tons/year) into the500-km long ethylene pipeline network.

Modern, low-cost standard solutions from a sys-tem provider offer maximum security for thepower supply. A double-busbar switchgear withfour busbar sections supplied by four incomingfeeders was installed. The busbars feed thehigh-voltage motors of the compressor plants andthe low-voltage network for supplying the tankfarm pumps. A switchgear that relied on compact,low-maintenance technology was essential.

Beside the new solution concept for the primarysystems, the secondary systems also requiredhighly efficient, state-of-the-art technology. Be-cause the compressor station motors are installedin an explosion-protected environment, the sec-ondary systems employ motor protection relaysthat comply with the requirements of ATEX 100and are certified by the PTB.

Simplest Possible Handlingfor Greater Security

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� The conceptIn collaboration with BP Cologne, Siemens PTDdeveloped a solution with the highest reliability atthe lowest cost, offering the following functionsand advantages:

� Combined units implement protection andcontrol functions to keep costs low.

� The station control system communicates withthe power system control center via the existingnoise-immune fiber-optic cables between thebuildings.

� The power system control center controls theswitchgear under normal operation. For thisreason, two control center terminals using astandardized IEC 60870-5-101 protocol connectthe station control system to the power systemmanagement and to the signaling system. Thebay control units feature convenient and reli-able local control options at the emergencylevel.

� The combined protection and control units linkto the station control system (station level) inthe control and signaling direction via the stan-dardized protocol IEC 60870-5-103.

� Simple, standardized, intuitive operation of theprotection and control units saves scarce per-sonnel resources. The equipment's comprehen-sive self-monitoring mechanisms reduce costsfor precautionary maintenance.

� Using the same software for establishing param-eters for all protection and control units cutsthe time and costs of training.

� Overcurrent protection functions and suitablemotor protection functions securely and reli-ably protect the outgoing circuits.

� The new phase-selective differential protectionof the four incoming feeders uses the existing fi-ber-optic cables connecting the buildings. Thisprovides maximum supply security using theexisting infrastructure, thereby reducing invest-ment costs.

� Overcurrent protection in the bay control unitsprotects the incoming feeder units. To protectthe investment against operator error, the inte-grated synchrocheck functionality allows usersto check the synchronous conditions beforeconnecting to the supply.

� Panel-internal interlocking can be installed forsafe operation of the switchgear. These are im-plemented in the devices by means of software.

The maintenance-free compact double-busbarswitchgear of type NXPLUS, in conjunction withthe matching numerical protection relays of theSIPROTEC 4 product range, provides the requiredhigh level of reliability.

Fig. 1System operations undernormal operation




The housing design with large detached operatordisplay was selected from the SIPROTEC 4 prod-uct range. This design allows installation in thecubicle door in an ergonomic position. It alsoprovides advantages with regard to operation, re-lay installation position, and mechanical stressingof the switchgear door.

The control and monitor-ing functions can be per-formed easily and reliablyon the relay display. Allrequired operator controlelements, such as the localkey-operated switch, areintegrated to avoid theneed for external add-onelements. The user-friendly design allows in-tuitive operation of thedevices even under emer-gency conditions, thushelping to ensure a reli-able supply of electricalpower for the productionprocess.

The integrated graphicallogic level (CFC) and acopper ring bus wiresacross the panels provide

the required switching interlocks. The interlockcheck prevents busbar sections from being acci-dentally coupled via the two outgoing feederdisconnectors of a feeder, and keeps the circuit-breaker of the bus sectionalizer from beingopened during this operating state.

Because of the modularity of the protection func-tions in the SIPROTEC 4 combined relays used,7SJ6 overcurrent-time protection relays can beused as standard and adapted to the object to beprotected. Relying on standard operations cuts therequired training time significantly, saving scarcepersonnel resources and reducing the risks of op-erator error.

Another positive point to be mentioned is the factthat fewer assets are tied up, because a lower stockof spares needs to be maintained.

In order to protect the high-voltage motors in theexplosion-protected areas of the compressor sta-tion, the 7SJ6 relays have suitable and proven mo-tor protection functions that are alsoATEX100-certified.

Fig. 2NXPLUS switchgear withSIPROTEC 4 relay

For this application, the 7SJ63 relays feature start-ing time supervision and restart inhibit for mo-tors. The former protects the motor againstexcessively long start-up processes, thereby pro-viding extra overload protection. The restart in-hibit prevents the motor from restarting if therotor is expected to heat up above the permissibletemperature during start-up.

The overload protection prevents thermal over-stressing of the objects to be protected. The pro-tection relay (with memory function) displays athermal replica of the object, taking into accountthe overload history as well as the heat dissipatedto the environment. This is of crucial importance,particularly in explosion-protected areas, since itis necessary to ensure that equipment tempera-tures do not reach levels that could trigger an ex-plosion.

The four incoming feeder panels have SIPROTEC7SJ64 numerical overcurrent time protection re-lays and 7SD610 line differential protection relays.Thanks to standard SIPROTEC 4 technologies,users can operate these relays simply and intu-itively according to the same philosophy, andparameterize and read them out easily using theDIGSI software, which is standard for all numeri-cal Siemens relays.

The 7SD610 line differential protection relaycommunicates via the existing fiber-optic cablesacross buildings.

Fig. 3SIPROTEC 4 relay with detached panel

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The integrated commissioning and monitoringhelp functions, based on Web technology, supportefficient commissioning of the line sections. TheWeb technology cuts commissioning times andopens up the following new options for the serviceand maintenance personnel:

� Graphic display of local and remote measuredvalues as vector diagrams

� Simple checking of the polarity of the trans-former terminals

� Stability tests with display of the operatingpoints in the tripping characteristic

Fiber-optic point-to-point connections link allSIPROTEC 4 relays to the station control systemSICAM SAS. Communications in the control andsignaling direction use the standardized protocolIEC 60870-5-103 between the bay unit and centralunit. The station control system SICAM SAS con-nects to the power system control center and thesignaling system via IEC 60870-5-101 protocol.

Fig. 4 Temperature characteristic of rotor

Fig. 5 Web browser in 7SD610

�ConclusionBecause of standard equipment technology, us-ers can operate the system safely even in emer-gency situations with little training, either fromthe control room or locally. The SIPROTEC 4relays support operations through self-monitor-ing and comprehensive logging of events andmessages.

Proven modular protection functions, adaptedto the application, protect the electrical equip-ment important to production, such asswitchgear, outgoing feeders, and motors. Thecontrol system logs and signals any faults imme-diately. As a result, users can analyze faultsswiftly and take appropriate measures to preventproduction losses. The all-in system solution,comprising primary and secondary systems,guarantees a high level of reliability for the entireplant, and ensures a reliable and efficient powersupply for the compressor stations and the tankfarm.

Fig. 6 Protection scheme

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Maximum permissiblerotor temperature

Temperature characteristic ofrotor rod top edgerotor rod bottom edge

Thermalreplica

1st start-up 2nd start-up 2rd start-up

Motor started Motor started Motor started

TRecoverytime

TRecoverytime

TRecoverytime




Unipolar disconnector control in the Kazakhstanproject

� The companyThe Kazakhstan Electricity Grid Operation Com-pany (KEGOC) is responsible for operating thatcountry’s entire electric power supply system. Toensure its continuing economic development, thisstill-developing country must not only expand itspower system but also ensure the reliability of itselectric power supply.

� The starting situationA vital objective was to improve the reliability ofpower transmission as well as the availability ofthe electrical equipment in the power system.KEGOC therefore awarded Siemens Power Trans-mission and Distribution (PTD) the order tomodernize the station control and protection sys-tems for all transformer substations ofKazakhstan’s electric power transmission system.But the existing switchgear had to remain in usewithout changes, which posed a special challengeto the bay controllers, since the switchgear wasonly suitable for unipolar control.

� The conceptTo maximize system reliability and stability, all 68transformer substations of the high-voltage andextra-high-voltage level (110 kV to 1150 kV) wereequipped with numerical protection and controlunits and with latest-generation substation con-trol systems. Analog electronic protection relayswere replaced by numerical SIPROTEC systems.

These devices were mounted in the switchgear cu-bicles and then installed directly at the construc-tion sites and commissioned. In addition, in thecontrol rooms of the transformer substations,conventional control panels were replaced bystate-of-the-art display workstations for the main-tenance personnel. The SICAM SAS substationautomation system was used in this application.Based on SICAM and SIPROTEC components,this system povides a uniform solution for thecontrol and monitoring of electrical transmissionand distribution systems. Other critical reasonsfor the Kazakh utility’s decision to opt for stationcontrol and protection systems from Siemens in-cluded the user friendliness of the system compo-nents, their reliability, long service life and the

Intelligent Technology forExceptional Requirements

Fig. 1 Substation in Kazakhstan

capability of making operational and diagnosticdata available.

� From practical experienceOur engineers have developed a solution for con-trolling the existing switchgear with state-of-the-art SIPROTEC 4 bay controllers. A unique ap-proach was used for controlling the disconnectorsin the KEGOC system. These disconnectors areoperated with a single-pole control scheme inplace of a double command for ON and OFF. Theactuation direction depends on the momentarystatus, i.e. when the disconnector is closed, thecommand will open it. If it is open, the same com-mand will cause it to close. But such a commanddoesn’t exist yet in the DIGSI information catalog.

An additional function of the SIPROTEC relaysand controllers will be to provide switching faultprotection during manual local operation, usingthe same contacts that are used for remote con-trol. Fig. 2 illustrates the configuration.

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The rectangles – Disconnector Q 1 throughDisconnector Q10 in the diagram – represent thedisconnector connection boxes. These can be con-trolled either by the instrumentation and controlsystem or by local control (pushbutton directly inthe switchgear cubicle). Switching between localand remote control is accomplished by means ofthe Remote/Local selector (on the right in Fig. 2),which is read by the SIPROTEC relay.

In the "Remote" mode, the disconnectors are con-trolled by the SIPROTEC relay, i.e. the connec-tions to local control that are represented byarrows are deactivated.

In this mode, every switching command triggers achange in the switchgear status. During these op-erations, feedback is detected as usual through twobinary inputs (OFF, ON, Fault). Disconnector Q1for instance is turned ON by the contacts BO1 andBO2 when it is OFF, and conversely, is turnedOFF when it is ON. These switching operationsare performed in accordance with the configuredinterlock conditions (switching fault protection).

In the "Local" mode, the disconnectors are con-trolled by pushbuttons directly at the switchgearcubicle. But during this operation too, the inter-lock conditions in the SIPROTEC must remain ineffect. Consequently, when switching the Re-mote/Local selector to the Local setting, the mean-ing of the command outputs BO2 through BO11must be changed: In this situation, SIPROTEC 4relay closes all contacts that have allocateddisconnectors whose interlock conditions are met.This logic allows those disconnectors to be con-trolled whose switching fault protection conditionis being met at a given moment.

� SolutionThis complex requirement was swiftly and easilymet by virtue of the flexibility of the DIGSI 4 op-erating program, the CFC editor contained in theprogram, and the latest device firmware. The ap-proach eliminated the need for a project-specificsoftware expansion (more contacts).

�Connections1. The unusual disconnector control scheme re-

quires that ON and OFF be connected to oneand the same contact. This hasn’t been possiblein the past. However, a detour via CFC logic canbe used to model an incoming command in aspecific message that is allocated to a single con-tact. Disadvantage: At present, the commandmust be allocated not only to the CFC destina-tion but also to binary outputs in order to be ac-tivated for initiation. In new devices (V4.6 ornewer) and DIGSI 4.6 this problem is elimi-nated. Allocation to the binary outputs is nolonger necessary.

2. Use of the commands "Q1 ON/OFF" through"Q10 ON/OFF" produces the same log to thecontrol and protection system as usual.

3. The corresponding outputs that are connectedto the disconnector contacts "BO2" through"BO11" are actuated via the CFC logic, and so ofcourse is the common contact "BO1".

4. All commands are interlocked; the conditions,which are stored in a separate group within theconfiguration matrix, are likewise generated inCFC logic.

5. The external Remote/Local selector is detectedat a binary input via the "Remote->Local" spe-cific message.

6. In the local control mode ("Local") single com-mands are also generated in the CFC under thegroup header Local Release. These single com-mands represent the interlocking release.

Fig. 2 Disconnector control at KEGOC




�ConclusionDue to the extraordinary flexibility of theSIPROTEC products and the DIGSI software,the engineeres were able to meet the very specialrequirements of this project without costly de-velopment of additional software or hardwarereplacement. The installation of Siemens pro-tection and control systems substantially re-duced system outages in Kazakhstan andprovided new incentives for investors.

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Fig. 3

Fig. 4 CFC logic for generating single commands out of double commands




SIPROTEC 7SA6 distance protection relay withinter-relay communication

� The starting situationAs the power supply systems are getting more andmore complex, special schemes for emergencysituations have to be implemented.In these special schemes, communication betweensubstations is a necessary feature.The 7SA6 distance protection relay provides acommunication functionality that allows an easierimplementation of special schemes.

In the case study described below, a customerstarted to construct a CIC substation to ensurepower transmission from a thermal power stationwith GG-1/ 2 and GT1.However, the substation did not get ready ontime, and the CSN consumer was not connectedto the bus. Therefore, the loads on the CCO –sideof the system proved to be too small.

With this situation, load loss on the transmissionline between the substations GRL and CCO wouldin fact mean an overloading of the transmissionline between GRL and CSO (see Fig. 2). This isusually the case, when the power generated in thethermal power station is above 290 MVA at thefault occurrence time. Therefore, an additionalload had to be connected to the system.

� The conceptThe solution was to implement a connection be-tween the GRL substation and the UMB substa-tion.In case of faults on the GRL-CCO transmissionline, this line will be disconnected and the TLGRL-UMB transmission line will be connected .Since the TL GRL-UMB has a higher thermallimit, this new configuration helps to solve theproblem.

The 7SA6 communication function was used toexchange the information between the GRL andCCO substations.When the main circuit-breaker or the load trans-fer breaker in the CCO substation opens due to atrip, the GRL relay receives the information byinter-relay communication. The “Special Emer-gency Scheme” is activated and then the relayoutput is reset.

Inter-Relay Communica-tion (R2R) and SpecialSchemes for Emergency

Fig. 1 System configuration

Fig. 2 System configuration under overload condition

Overload




� Special advantagesThe inter-relay communication is used to simplifyexchange of information between the substationsand relay-internal carrying-out of the logic se-quences.

This application uses only 2 remote signals, leav-ing another 26 signals for further applications.The 7SA6 work with a fast and very reliable proto-col .Due to the flexibility, upward and downwardcompatibility is provided at all times and commu-nication via various communication media is alsopossible (see Fig. 4).

�ConclusionAs shown in this case study, Siemens configuredthe “Special Emergency Scheme” for the cus-tomer by use of the SIPROTEC 7SA6 distanceprotection relay for all voltage levels. All re-quirements of the customer were met. This newscheme allows communication between thesubstations and therefore – if necessary - theautomatic activation of special emergencyschemes.

Fig. 3 Solution with inter-relay communication

Fig. 4 Options for communication media


Fig. 1 Lage der Schaltanlage Cafayate



SIPROTEC protection systems of the latest genera-tion in Argentina

� The companyEDESA is a power supply company in the prov-ince of Salta. The integration of the local substa-tion in island operation into the Argentineanpower supply system (SADI) was a challenge forEDESA, especially as all new substations have tocomply with special standards and, like any pri-vate investment, must be profitable.

EDESA awarded Siemens the contract to imple-ment the incorporation of the city of Cafayate intothe SADI power system.

� The starting situationPower generation in the Northwest of Argentinais mainly thermal. The power system is character-ized by transmission lines with average distancesof 100 km, large loads located in the main citiesand medium-sized customers scattered over alarge area. EDESA’s task was to build up a substa-tion in Cafayate with the following features:

� Optimum protection

� Integration of many functions in one device toreduce space requirements

� Telecontrol function

� Cost-effectiveness

For the Pampa Grande substation that had to beconnected to the Cafayate substation, EDESA de-manded a solution for a reliable and efficient op-eration.

� The conceptThe Cafayate substation project comprised theconstruction of a T-line configuration in the mid-dle part of a 132 kV transmission line connectingtwo substations: Trancas in the province ofTucuman and Cabra Corral in the province ofSalta.

The new, 130 km long transmission line starts atthe Pampa Grande substation.

State-of- the-ArtProtection for CafayateSubstation

The Cafayate substation featured the following:

� Panel for a power transformer (132 kV/33kV,20 MVA)

� HV circuit-breaker

� Medium-voltage switchgear with transformerpanel and three panels for outgoing feeders,supplying the Cafayate area with power

� Isolated operation with local power generationas backup option only.

Communication between Cafayate – PampaGrande, Pampa Grande – Cabra Corral and CabraCorral – San Francisco substations is via SiemensDigital Power Line Carrier ESB2000i and an inte-grated SWT3000 teleprotection equipment. Fourindependent commands are transmitted via aninterconnection data transmission channel.

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For the Cafayate substation Siemens offered anintegrated solution, comprising:

� 7SJ63 multifunction relay for the 13.2 kV me-dium-voltage switchgear, including protectionand control and measuring functions plus inter-facing for telecontrol systems.The following protection functions are applied:

– Directional and non-directional overcurrentprotection

– Auto-reclosure

– Over/undervoltage protection and

– Over/underfrequency protection

� 7UT633 relay for protection and control of thepower transformer with differential protectionfor a three-winding transformer plusovercurrent protection as backup protection.

In one single panel EDESA integrated the trans-former protection functions, the automatic volt-age control, the thermal replica relay and theBuchholz protection. Control and protection canbe either local or remote via telecontrol systems.

For the Pampa Grande substation the 7SA522protection relay which covers a wide range of pro-tection functions, has been chosen. It features thefollowing:

� Non-switched distance protection with 6 meas-uring systems (full scheme)

� 5 independent distance zones

� Auto-reclosure (1 pole and 3 pole) (with ADTfunctionality)

� Synchro-check

� Switch-onto-fault

� High resistance earth-fault (directional ornon-directional)

� Phase-overcurrent protection

� Power swing detection/blocking

� Teleprotection for distance protection(PUTT/POTT)

� Fault locator

Remote control is effected by DIGSI remote con-trol query of the Pampa Grande 7SA522 distanceprotection. The operator staff may control andchange the settings and download fault and eventlogs.

In the first zone the 7SA522 distance protectionrelay measures in the direction of the transmissionline to Cafayate substation, which is 80 % of theline length. This means that the fault disconnec-tion and clearance times for the transmission linesections from Pampa Grande to Cabra Corral andTrancas have to be kept to a minimum.

Fig. 2 Zone setting of 7SA522 relay

Fig. 3 Zone setting according to Criterion A

Fig. 4 Zone setting according to Criterion B




Among others, two main criteria had to be con-sidered:

Criterion A (see Fig. 3)

1) Distance protection ZPG (7SA522) measures infirst zone (Z1) 80 % of the line length in thedirection to the Cafayate substation (forward).In the second zone (Z2) the remaining 20 % ofthe line are measured and at the same time therelay serves as backup protection for the powertransformer. In the third zone (Z3) 60 % of theline length measured from Pampa Grande aremeasured in reverse direction.

2) 80 % of the line length Cabra Corral – PampaGrande and Trancas - Pampa Grande are meas-ured in the first zone (forward direction) by thedistance protection relays ZCC and ZTR. Anoverreaching zone of 115 % is formed in thesecond zone Z2 with the substation at the re-mote line end.

3) For the distance protection relays ZCC and ZTR,the settings of the independent zone Z1B corre-spond to those of the second zone Z2.(Z1B = Z2).

With these settings, different types of faults wereanalyzed (Fig. 3) with the protection relays show-ing the following behavior:

1) Fault F 1: Distance protection relay ZPG trips inthe first zone (Z1) and since the other two pro-tection relays are measuring in the second zoneZ2, ZPG trips first in tZ1.

2) Fault F 2: Distance protection relay ZPG meas-ures the fault in the third zone (Z3) in reversedirection and sends a signal to the protectionrelays ZCC and ZTR to release to the independentzone Z1B and both protection relays clear thefault .This signifies: signal transmission time + triptime of Z1B (tZ1B) = reaction time.

3) Fault F 3: In this case protection relay ZTR tripsin minimum time (tZ1) and the ZCC receives therelease signal for the independent zone Z1B

This signifies: signal transmission time + triptime of Z1B (tZ1B) = reaction time.

Criterion B (see Fig. 4)

1) Distance protection ZPG (7SA522) measures infirst zone (Z1) 80% of the line length in the di-rection to the Cafayate substation (forward). Inthe second zone (Z2) the remaining 20 % of theline are measured and at the same time the relayserves as backup protection for the powertransformer.

2) 120 % in direction of the lines Cabra Corral –Trancas and Trancas – Cabra Corral are meas-ured by the distance protection relays ZCC andZTR in the overreach zone (Z1B). Both workingin POTT teleprotection scheme (a release signalhas to be received from the remote end so thatthe distance relay locally trips the cir-cuit-breaker). The trip time for zone Z1B of pro-tection relays ZCC and ZTR should be greaterthan the trip time for the first zone of protec-tion relay ZPG.This results in time selectivity between thetransmission lines Pampa Grande – Cafayateand the other two transmission lines with re-gard to faults on the first line.

With these settings, different types of faults wereanalyzed (Fig. 4) with the protection relays show-ing the following behavior:

1) Fault F 1: Distance protection relay ZPG trips inthe first zone (Z1). And because the other twoprotection relays have a longer time for trip-ping the first zone, relay ZPG is the first to trip intZ1.

2) Fault F 2: Distance protection relays ZCC andZTR measure the fault in overreach zone Z1B and– after a release command - both protection re-lays clear the fault. Trip time therefore is: signaltransmission time + trip time Z1B (tZ1B)

3) Fault F 3: same as in 2)

After analyzing and evaluating the two criteria,criterion B was opted for, aiming at homogeneitywithin the system.




� The special advantagesThe distance protection 7SA522 provides the fol-lowing:

� Minimized fault clearing time in the differentsections of the transmission lines from PampaGrande to the other substations.

� Unnecessary three-phase trips, caused by simul-taneous single-phase faults in different phaseson both transmission lines, are avoided.

� Service life of circuit-breaker is prolongedthanks to reduction of unsuccessful auto-reclosures.

�ConclusionSince January 2004, the Pampa Grande andCafayate substations have been in operation tothe customer’s full satisfaction.EDESA has integrated the power supply for thecity of Cafayate into the Argentinean powersupply system. Thanks to the SIPROTEC pro-tection relays, the Cafayate substation is nowbeing protected by an optimal and cost-effectiveprotection concept.




Intelligent protection systems spare LEW powersupply company expensive power system expan-sion

� The companyLechwerke AG (LEW) is one of the largest re-gional power supply companies in southern Ger-many. Its core business consists of electric powersupply and all related services. The area suppliedby its power supply system covers 8,245 square ki-lometers and is mostly located in the provincialadministrative district of Swabia. LEW also sup-plies electric power to some adjacent portions ofUpper Bavaria.

To provide power to its 885,000 directly and600,000 indirectly supplied customers, LEWmaintains a medium-voltage system 7,198 kilome-ters in length, a 380/220/110 kV high-voltage sys-tem with a total length of 2,429 kilometers, and104 transformer substations.

� Initial situationThe Lechhausen substation feeds a fairly large mu-nicipal utilities company. In normal operation,the energy demand is met over a 380 kV/110 kVsystem interconnection from the 380 kV system. Asecond system interconnection exists as a backuptransformer in the Lechhausen substation but re-mains disconnected in normal operation.

A rise in the municipal utilities company’s powerdemand created the risk that a failure of the380 kV/110 kV supply transformer would causetrips on faults due to power system overloads inthe 110 kV system. This would interrupt the sup-ply to the connected municipal utilities company.

To increase the power transmission from the110 kV system in the Lechhausen substation, asubstantial and costly power system expansionwould have been called for. Among other require-ments, an additional overhead line would havehad to be looped into the Lechhausen substation,and the substation would have had to be expandedby two additional switchgear feeders with circuit-breakers.

The Numerical Advantagein Protection Technology

Fig. 2 110 kV power system configuration

Fig. 1 Gersthofen hydro power plant of LEW

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� The conceptIn view of such high cost estimates, LEW devel-oped an alternative concept that also effectivelyprotects against a power failure – but at much lessexpense.

The solution was to integrate the Lechhausen sub-station via a dual tie line into the 110 kV powersystem, which resulted in a three and a fourline-ends configuration. As a result, it was possi-ble to increase the available level of power trans-ferred from the 110 kV power system with theexisting circuit-breakers and switchgear panels. Afailure of the 380 kV/110 kV transformer can nowbe compensated by the 110 kV power systemwithout causing power outages in the dependentmunicipal utilities company. The multi-end con-figuration also made it possible to increase theshort-circuit power in the 110 kV power systemand to optimize the load flow.

To provide selective and fast protection for thisthree and four line-end power system configura-tion it was necessary to expand the existing dis-tance protection relays by a line differentialprotection relay capable of protecting even threeand four line-ends.

The existing distance protection would not havebeen able to protect the new power system config-uration selectively and swiftly in all cases. In com-bination with the line differential protection relay,the distance protection now also functions asbackup protection.

Lechwerke decided in favor of the SIPROTEC7SD52 multi-end differential protection relay,which can protect up to six line-ends. The existingdistance protection was augmented by one 7SD52differential protection relay per switchgear feeder.

Fig. 3 Protection scheme of a three and four line-end configuration




No current transformers or circuit-breakers existin the 110 kV lines at the Stätzling substation. If afault occurs, the existing switch disconnectors inthe feeders can’t shut off the short-circuit current,which causes the line differential protection to tripthe circuit-breakers of the transformers in such anevent. The current is measured at the bushing-type current transformers of both transformers.The measured values are adjusted via a summa-tion transformer and transmitted to the 7SD52.This adjustment via a summation transformer wasfeasible because the installed 7SD52 required verylittle power from the transformer.

Since no direct communication links exist be-tween the different substations for the transmis-sion of protection data, this is provided betweenthe differential protection relays via a digital PCM(Pulse Code Modulation) communications net-work. The adaptation to the digital communica-tions network in turn is implemented via externalconverters by means of a synchronous electricalX.21 interface to effect the connection to the com-munications devices. With these communicationconverters, two protection relays can communi-cate synchronously with each other and exchangelarge data volumes over long distances.

� The special advantagesTo further increase the availability of the system,Lechwerke decided to equip all of the installed7SD52s with two R2R interfaces. As a result, eachprotection relay can exchange data with twoneighboring relays – so that a ring topology can beestablished for the exchange of protection data.

Failure of a communications connection betweentwo devices does not result in blocking of the dif-ferential protection function, since the devices de-tect this condition and re-route ring topologyautomatically to chain topology while the differ-ential protection function is immediately reacti-vated.

�ConclusionConversion of the existing 110 kV power systeminto a three and a four line-end configurationmade it possible to increase the short-circuitpower at the Lechhausen substation and to sub-stantially improve the reliability of the powersupply to the connected municipal utilitiescompany, without requiring large investmentsin primary technology. The use of state-of-the-art SIPROTEC numerical protection tech-nology made it possible to safely and selectivelyprotect the resulting, complex power systemconfigurations. The use of existing communica-tion channels made it unnecessary to invest innew fiber-optic connections in the communica-tions network.




Protection systems Deutsche Steinkohle AG candepend on

� The companyDeutsche Steinkohle AG (DSK) resulted from themerger in 1998 of two mining companies,Ruhrkohle AG and Saarbergwerke AG. In 2003,the company sold 27 million metric tons of coal,most of it to German power supply companies.

� The starting situationUnder-ground mining poses electric power re-quirements that differ from those in normal utili-ties’ power systems. This is true with respect toprotection systems. Protection relays must be ableto respond to faults in a fail-safe manner, even inexplosion-hazardous areas. Special requirementsalso pertain to communications in explosion-haz-ardous areas and to auxiliary power supply, sincebatteries are prohibited as a power source in un-derground mines . In upgrading the incomingsupply to a 10 kV power system, DSK opted for aSIPROTEC 4-based design that meets these re-quirements completely.

� The conceptThe SIPROTEC 4 product range of protection re-lays is highly flexible and can be safely used in un-derground mines. The version used is the ATEX-compliant 7SJ62 relay for protection of explosion-protected motors with the elevated level “e” ratingof explosion protection. When used in explosion-hazardous areas with methane gas and electricallyconductive coal dust, devices must comply withthe “explosion-proof enclosure” type of protec-tion. To meet this requirement, they are installedin the BARTEC 8SN enclosed switchgear fromSiemens.

� The special advantagesCommunication despite enclosureThe installation within the enclosed, explo-sion-proof switchgear means that it is not feasibleto go online with the protection relay via a wireconnection to the DIGSI computer. To communi-cate with the laptop through the sealed glass win-dow, an infrared adapter is therefore connected tothe front interface of the 7SJ62 and simulates a se-rial interface.

SIPROTEC – Down in aCoalmine

Fig. 1 Coal mine of DSK

Fig. 2 Siemens Bartec 8SN encapsulated switchgear

Explosion-proof housingwith 7SJ62

Infrared-interface

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Communication with the world aboveAn intrinsically safe modem installed within theexplosion-proof enclosure maintains communica-tions to the outside world via the systems interfaceusing PROFIBUS-FMS protocol. Actions such asreadouts of operational information, switchingevents and protection settings can therefore beshifted above ground.

Visual display of informationThe personnel on site should be able to obtain asmuch information as possible in visual form –without having to access operational messages orsystem fault messages by operating keys. Toachieve this, SIPROTEC 4 relays can be addition-ally programmed by means of CFC logic blocks tocause optical indicator lights (LEDs) on the frontplate to either blink or illuminate continuously, asdesired. This means: In a 7SJ62 relay with 7 LEDsit is possible to display 14 different statusindications.

The protection relays are installed in a 10 kVswitchgear panel. The motors for the belt convey-ors, longwall conveyors, coal-cutting machine andtunneling operations in the longwall are located inthe outgoing feeders. A characteristic feature isthat these motors are constantly being relocated asthe mining progresses. What’s more, the long dis-tances in the mine network to the coal face beingcut pose special requirements that must be con-sidered.

CFC logic detects short-circuits promptlyThe basic rule of selecting a motor short-circuitsetting above the highest starting current and be-low the 2-pole short-circuit level does not applyhere. Due to the long distances, the short-circuitcurrent may be lower than the starting current.The longwall conveyor motors are tuned to eachother and start up sequentially within a short timeinterval, so that the total current continues to in-crease and exceeds the short-circuit level.

The use of CFC logic solved this problem: Thepickup threshold is increased stepwise by detect-ing the motor start, so that no spurious trippingoccurs yet a motor short-circuit can be detectedpromptly.

Fig. 3 Typical 10 kV power system in a coal mine

Fig. 4Self-adaptation oftriggering thresh-old during motorstart

Self-adaptation of triggering threshold during motor start

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Auxiliary power via voltage transformerAnother special aspect of underground mining isthat batteries cannot be used for auxiliary powerdue to the explosion hazard. Protection relays aresupplied through the voltage transformer (fre-quently only a single phase-to-phase voltage isavailable). However, tripping must be prompt ifthe voltage falls below the minimum level (<70%)to ensure that there is sufficient voltage to actuatethe undervoltage coil.

Tripping assured to the nth degreeWith these factors in mind, a breaker-failure pro-tection is also provided, in the event that the firstundervoltage tripping signal fails to open the cir-cuit-breaker.

If the first TRIP command is ineffective, thebreaker-failure protection attempts to use a storedsignal (lockout) to issue a TRIP signal to the samecircuit-breaker. Reasons for the voltage dip mayinclude:

� a voltage failure due to the incoming supply be-ing shut off

� a voltage drop due to the starting of large mo-tors

� a voltage dip due to a short-circuit

As a last resort, if the breaker-failure protectionalso fails or the supply voltage is already too low,the live-contact status of the protection relay tripsvia the undervoltage coil.

PE conductors provide fault detectionSince the supply cables are accessibly located alongthe longwall, there is always a possibility that theymay suffer some minor impact damage. To detectsuch faults promptly before any critical damage issuffered by the phase cables, PE conductors areprovided underneath the outer cable sheath. Inthe event of a fault, these conductors triggeralarms in the protection relay via the binary in-puts, similar to the trip circuit supervision func-tion.

No information lossSupplying auxiliary power to the protection relaysvia voltage transformers rather than by batteryvoltage causes more frequent switching off of theSIPROTEC relays during operation. It is thereforeall the more important that all essential processinformation remain stored in the protection relay,to be available to the operator for analysis oncenormal power is restored. Because even simplesignals via the binary inputs can cause the cir-cuit-breaker to trip, for instance if the environ-mental monitor issues a methane gas alarm.

Fig. 5 Power supply in a coal mine

Automatic reconnectWhen the protection relay is operational againand no further interlocks or messages requiringacknowledgment are outstanding, reconnectionsare established automatically. To prevent all loadsfrom being reconnected to the supply simulta-neously, which could cause large line voltage fluc-tuations even above ground, each 7SJ62 has storedits individual reconnect time in the CFC schemeand reconnects the respective circuit-breaker sep-arately after a time delay of several seconds.

�ConclusionSIPROTEC relays have been used at DSK to im-plement a protection system that is more thanadequate to meet the special requirements ofcoal mining.Special underground requirements such as

- application in explosion-hazardous areas

- readout of fault records via infrared interface

- auxiliary supply of the relays by voltagetransformers

- recording of fault-related data after supplyvoltage failure

were successfully met and solved optimally withSIPROTEC protection relays.

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Fig. 6 Tunneling operation

Fig. 7 Coal-cutting machine at work

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SIPROTEC 7SA6 with auto-reclosure on mixed lines

� The companyWith about 2,900 employees and sales of aroundEUR 1.3 billion, Stadtwerke Hannover AG is oneof Germany’s largest municipal utilities compa-nies. Under the brand “enercity – positive energy”,they offer power, water and services to private andcommercial customers. In the Hanover region,municipal utilities company Stadtwerke Hannoverprovides around half a million people with elec-tricity, natural gas, district heating and drinkingwater and is currently supplying about 8,000 de-livery points nationwide. Thanks to their coopera-tion with various partners, municipal utilitiescompany Stadtwerke Hannover is also able to pro-mote customer-oriented offers on a national level.In the commercial customer sector, the companyoffers the full range of services associated with en-ergy management, including consulting, planning,new construction and refurbishment, and plantoperation. Their nationwide commitment is prov-ing successful: 2002 was the first year thatStadtwerke Hannover sold more electricity out-side its original service area than inside it. In 2003,they further increased sales to just under 19,500GWh (service area: 3,285 GWh).

� The starting situationStadtwerke Hannover, enercity requested the im-plementation of 7SA6 distance protection overmixed lines. This application is not limited to aspecific plant but can be employed in a variety ofapplications. Mixed lines means that part of thesection to be protected within a grading zonecomprises cables and another section consists ofoverhead lines. The auto-reclosure (AR) functionwould be appropriate for the overhead line sectiononly. The sections to be protected must be selectedaccordingly (see Fig. 2).

SIPROTEC 7SA6 with Auto-Reclosure on Mixed Lines

� The conceptFor sections with both cables and overhead lines,distance zone signals (resistance (R) and reactance(X)) can be used within a certain framework todifferentiate between cable faults and overhead-line faults. With the appropriate interconnectionsby means of the programmable logic functions(CFC), auto-reclosure can be blocked when a faultoccurs in the cable section.

�ConfigurationAs usual, the line sections are grated in the 7SA6distance protection relay into distance zones Z1,Z2, Z3 and Z5, depending on the power systemconnection. Zone Z1B is primarily used for theauto-reclosure function and for connection func-tions (“Hand-Ein” = manual close). Zone Z4serves to measure and select the segments of cableor overhead line in the sections to be protected.Besides being used for the auto-reclosure function(AR), Zone Z1B is also employed for instanta-neous switch-onto-fault tripping for the sectionsto be protected. The protection system must betripped instantaneously when connecting to thesection to be protected if, for example, the groundelectrode is still inserted at the remote end. Alter-natively, this functionality can also be imple-mented in the 7SA6 by means of the“instantaneous high-current tripping” function.

Fig. 1 Trademark of municipal utilities company Stadtwerke Hannover

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This description of the application is based on ageneral section <A – B> with two 7SA6 distanceprotection relays. For the protection relay at in-stallation location “A”, the solution includes dis-tance zones Z1B and Z4. The protection relay atinstallation location “B” can be configured for ARon mixed lines either by means of distance zoneZ1B and instantaneous high-current tripping or,alternatively, in accordance with solution “A”with the grading of zones Z1B and Z4.

Settings for project planning in DIGSIFirstly, the following entries must be made in theparameter set for the 7SA6 by means ofparameterization in DIGSI.

Configuration matrix (Group: “AutomatischeWE” (auto-reclosure) or “Dis general”):

Parametrization: (Parameter group A,distance protection - polygon, zone Z4)parameter 1335 “Delay time T4”

Tripping time for zone Z4(parameter 1335 = T4) has to be set to indefinite(T4 = ∞) because this zone is only used for select-ing the cable or overhead line sections of this line.In this application, zone Z4 is to indicate only onepickup. Tripping is not relevant in this zone. Espe-cially in the case of a single-pole auto-reclosurefunction this setting is important, because thentripping may only initiated via zone Z1B.

Creating the logic sequencesAll that is left is to create, link and translate thecorresponding CFC logic diagrams in DIGSI. TheCFC priority class used is the “Fast” PLC Task(PLC0). The individual logic functions and theireffect on the protected zone are described below.

For the section <A – B> described, appropriate al-locations must be implemented in both distanceprotection relays for detecting the AR range onthe overhead line.

Controlling auto-reclosure in 7SA6 for protectionrelay A7SA6 – protection relay A

Zone Z4 is graded in accordance with the R and Xvalues of the cable section. As usual, Zone Z1B isdimensioned to approx. 120% of the line length.Because AR should not be executed in the cablesection, the overhead line section in Zone Z1B isselected by means of a CFC. The result of the CFC(FNo. 2703 : “>AR block") is that auto-reclosureis blocked when a fault occurs in the cable zone(Zone Z4), see Fig. 4.

Fig. 2Mixed-line configuration

a FNo. 2703 >Block AR configured to"Destination CFC"

b FNo. 3747 distance protection pickup in ZoneZ1B, L1E configured to"Destination CFC"

c FNo. 3748 distance protection pickup in Zone Z1B, L2E configured to"Destination CFC"

d FNo. 379 distance protection pickup in Zone Z1B, L3E configured to"Destination CFC"

e FNo. 3750 distance protection pickup in Zone Z1B, L12 configured to"Destination CFC"

f FNo. 3751 distance protection pickup in Zone Z1B, L23 configured to"Destination CFC"

g FNo. 3752 distance protection pickup in Zone Z1B, L31 configured to"Destination CFC"

h FNr. 3759 distance protection pickup in Zone Z4 configured to"Destination CFC"

Fig. 3 Zone grading of distance protection relay A




Controlling auto-reclosure in 7SA6 for protectionrelay BSolution 1:

7SA6 with Zone Z1B and instantaneous high-cur-rent tripping:

7SA6 – protection relay B

Zone Z1B is graded in accordance with the R andX values of the overhead line on which the ARfunction should be executed. For instantaneousswitch-onto-fault tripping, the instantaneoushigh-current tripping function is used in the 7SA6for the full protection of the <A – B> section.

Solution 2:

7SA6 with grading of zones Z1B and Z4:

7SA6 – protection relay B

Zone Z4 is graded in accordance with the R and Xvalues of the overhead line. As usual, zone Z1B isdimensioned to approx. 120% of the line length.Because AR should not be executed in the cablesection, the overhead line section in zone Z1B isselected by means of a CFC. The result of the CFC(FNo. 2703 : “>AR blk") is that auto-reclosure isblocked when a fault occurs in the cable section(i.e. pickup in Z1B and no pickup in Z4).

Fig, 5 Setting of zone Z1B in relay B

Fig. 6 Grading of zones Z1B and Z4 of relay B

Fig. 4 CFC logic diagram for AR control for relay A

>AR blk.(FN°. 2703)

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Fig. 7 CFC logic diagram for AR control for relay B

>AR blk.(FNo. 2703)

� The special advantagesThe division into two distance protection zones(Z1B and Z4) makes it easy to select the cable andoverhead line sections in the event of a fault.

� From practical experienceIn practice, the auto-reclosure function can be ex-ecuted on the overhead line only. A fault in the ca-ble section immediately results in a lockoutcommand.A similar, slightly modified CFC function for ap-plication in an other distance zone was success-fully implemented for the Stadtwerke HannoverAG.

�ConclusionIn the past, sections could either be protectedwithout any selectivity or else separate sectionswere required for the cable and overhead linesections. Today, thanks to CFC add-on logic,offered as standard feature of SIPROTEC thecomplete line length can be covered intelligentlywith 2 relays thus requiring much less primarytechnical outlay.




Potential savings through new concepts in protec-tive relaying

� The companyEVI – the power supply company in Hildesheim –is a regional utility company for electricity, gas,water, and local heat. It provides services to theapproximately 110,000 residents of the city ofHildesheim. For power supply in the medium-voltage range, EVI operates a 20 kV power systemas an all-cable system with about 500 stations, in-cluding main switching stations, power systemprotection stations, and transformer stations. Up-stream supplier Avacon supplies the energy forthis medium-voltage power system using threetransformer substations. EVI operates its me-dium-voltage power system with impedancegrounding at the star point.

� The starting situationA standard power system protection station fromEVI is built as a three-feeder system equipped withtwo cable feeder and one transformer. Until nowin these stations, a Siemens 7SA500 numericaldistance protection relay has protected each of theoutgoing cable feeders. A remote terminal unit re-cords the information from the distance protec-tion relay and the power system protection stationusing single-fiber wiring. The unit forwards theinformation to the power system control centerthrough other gateways. EVI operates an extensivetelecontrol network for transmitting the informa-tion.

In the monitoring direction, the scope of informa-tion of the standard power system protection sta-tion consists of the following messages: supplyand protective voltage missing, DC voltage systemmalfunction, system control on site and devicemalfunction, distance protection relay, and faultlocator.

The distance protection pickup and distance pro-tection tripping are transmitted as measured val-ues from each of the two existing distanceprotection relays. If protection trips, the fault lo-cation measured by the protection relay is alsotransmitted in this manner. Furthermore, eachoutgoing cable feeder transmits the present mea-sured value of the outgoing current. In the controldirection, information transmitted also includesCLOSE/TRIP commands for each of the twocircuit-breakers and a reset command for trans-

Greater Safety for ExistingTechnology

mitting the fault location of the distance protec-tion. As a result, the total volume of informationincludes about 14 messages, 4 measured values,and 5 commands for each power system protec-tion station.

The telecontrol systems is over 20 years old, andthe protection relay system about 15 years. As aresult, there has been an increased incidence ofequipment failure in the past two years. The ongo-ing costs for repairs, spare parts, service and han-dling have continued to climb. The switch tomodern engineering became economically neces-sary.

Fig. 1 Line configuration of EVI utility Hildesheim, Germany

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In switching to new equipment, the companylooked for cost-effective standard solutions.Rather than replace the existing technology one-for-one with modern equipment, EVI establishedthe following criteria for the modernization:

� Modernize 10 substations initially, using thesame technology.

� Choose an optimal cost-to-performance ratiofor the new technology.

� Use the same hardware for distance protectionand telecontrol in these systems.

� Maintain at least the same functionality of thepower system protection station while reducingthe number of primary components in thesubstation.

� Replace the two existing distance protection re-lays with a single relay that ensures at least thesame functionality.

� Avoid using single-conductor wiring betweenthe distance protection and telecontrol.

� Use the standardized IEC 60870-5-103 interfaceto transmit the protection relay’s informationand measured operational values to a higher-level telecontrol unit.

� Specify a telecontrol unit that can record infor-mation from the protection relay via the stan-dardized IEC 60870-5-103 interface andtransmit this information and other data to agateway via the standardized IEC 60870-5-101interface.

� Connect the telecontrol units on a polling modedemand basis. This method will ensure optimaluse of the communications line network re-sources and a low interface demand to thehigher-level gateway.

� Specific new devices with easy, intuitive operati-on and parameterization, requiring a minimaltraining period.

� The conceptA new concept was developed according to thesecriteria that calls for one distance protection relayfor two outgoing cables. EVI selected the SiemensSIPROTEC4 7SA61 distance protection relay anda suitable telecontrol unit for transmitting.

The new 7SA61 distance relay was to take over thetasks of the two old existing distance relays. As aresult, the 7SA61 connects to one current-trans-former assembly and only one outgoing feeder.The second current-transformer assembly in theother outgoing cable is no longer needed and isavailable for other systems. This configuration canbe implemented in the EVI network because of thering structure of the cable network, with the op-tion of redundant feed-in from both ends.

Our experience with numerical protection relayshas shown that the risk of an uncontrolled failureis low. Self-monitoring in the numerical protec-tion relay is expected to lead to high availability.The low failure rate and the associated rapid deliv-ery service from PTD PA strengthens the system.

If a fault current occurs, the new Siemens 7SA61distance relay selectively trips the faulty line in thesystem for the forward or backward direction viathe corresponding circuit-breaker.

Fig. 2 Schematic diagram of the SIPROTEC 7SA61distance protection relay connection




Fig. 4 Geographical zone grading of the distance zones using station 2 as an example

For this purpose, the following parameters are setin the 7SA61 distance protection relay (see Fig. 3and 4): The settings of the parameters of zones Z1and Z2 indicate the forward direction, while theparameters of zones Z3 and Z4 indicate thereverse direction. In zone Z5 there is an X-valueeach for the forward and reverse directions. TheR-value of zone 5 is always set to the largerR-value of the two cable runs regardless of the di-rection. This solution is acceptable, since thisvalue deals with the grading in the second backupstage (grading: “Z1–Z2–Z5 (forward)”) and“Z3–Z4–Z5 (reverse)”). In addition, the 7SA61distance protection provides a directional and anon-directional time zone as the end time forgrading.

If a fault occurs, the result is processed direction-ally in the distance protection. This directional in-formation about the pickup and the tripping isgenerated in the 7SA61 protection relay for thefirst zone (“trip forward” = Z1, Z2, Z5 (forw))and the second zone (“trip reverse” = Z3–Z4–Z5(rev.)“) using a CFC function, output to the ap-propriate circuit-breaker. The information is alsoforwarded to the telecontrol unit (RTU) over theIEC 60870-5-103 interface.

Circuit-breaker failure protectionWhen a fault occurs, if the associated circuit-breaker of the system does not trip after a set timeof 100 ms in spite of the TRIP-command from the7SA61 protection relay, and if at least 1.2 times therated through-current is still flowing via the sys-tem’s current transformer, the protection relaydetects the situation and a logic function shuts offthe adjacent circuit-breaker. This function servesas circuit-breaker failure and busbar protection.

Telecontrol connection of the power system pro-tection stationVital boundary conditions for the new telecontrolunit include the serial interfaces for unit connec-tions in accordance with IEC 60870-5-101 andIEC 60870-5-103 protocols. The telecontrol con-nection is implemented on a polling mode basison a line with up to five stations (see Fig. 5). Thisline connects to an interface of the higher-levelgateway by means of the IEC 60870-5-101 proto-col. The gateway’s task is to concentrate informa-tion from telecontrol lines and telecontrol unitsand forward it to the control system.

The telecontrol system in the respective powersystem protection station transmits the informa-tion from the local input/output modules and theinformation from the Siemens distance protectionrelay connected via the IEC 60870-5-103 protocolto the gateway.

Fig. 3 Zone grading of the distance relay

Fig. 5 Telecontrol unit (RTU) operating in polling mode with a protection connection




� The special advantagesThe tested, flexible technology allowed a powersystem protection station to be modernized inonly three days. Little time was needed for wiring– especially when connecting the distance protec-tion – since all information is transmitted bystandard data cable via a serial RS485 interface.

When an event occurs, all information from theprotection relay – such as pickup and tripping in-formation, operational and fault signals, and themeasured value of the identified fault location – istransferred to the telecontrol unit over theIEC-103 interface. The R- and X-values of faultlocator are transmitted to the control center overthe serial interface. All information is availablequickly, so users can analyze the fault locationquickly and correctly regarding the direction ac-cording to the mathematical sign of thetransmitted value.

The standardized measured-value message withthe values for I, U, P, Q, as well as the frequency, istransmitted cyclically from the protection relay.Due to the very high accuracy of the 16 bits fordigital transmission of the measured values, thesevalues are now – for the first time – also conveyedfrom each of the modernized power system pro-tection stations to the control center. The controlcenter integrates these values in load manage-ment.

After the power system protection station wasmodernized, primary and secondary tests ensuredproper functioning for protection and precisetelecontrol system and transmission of the infor-mation for all sorts of faults.

� From practical experienceA fault in EVI’s 20-kV medium-voltage systemprovided real-world confirmation for the solu-tion. Two days after one power system protectionstation was modernized, a phase-to-earth fault inan outgoing transformer station in the 20 kV net-work “tested” all functions of the telecontrol andprotection relaying system. The protection cor-rectly detected and processed the fault in the net-work and trip the faulty the station. The systemproperly recorded, processed, and transmitted allfault-related information to the control center,and so it was possible to remedy the fault quickly.

�ConclusionConversion to the new SIPROTEC protectionsystem has paid off for EVI in many respects.The safety of the network increased significantlywithout requiring replacement of a large part ofthe existing systems, and without exceeding thebudget. The solution also clearly improved thesystem’s transparency in cases of fault. EVI cannow analyze, trace, and clear faults morequickly.




Differential protection over conventional pilotwires at the Varel paper and board factory

� The companyThe paper and board factory Varel in the north ofGermany (see Fig. 1) occupies the region suppliedby the Weser-Ems power supply company (EWE).The company operates its own power generationplant, which runs on natural gas and biogas, toproduce heat and power.

� The starting situationA new switchgear has been installed on the factorycampus. A 20 kV double feeder safe-guards thefactory's power supply, and can exchange powerover two approximately 0.5 km long feeder cables.

The power supply company recommended differ-ential protection relay 7SD51 to protect the cables.The relay had already proved viable for the protec-tion of short cables, and for reasons of standard-ization it made sense to specify it here as well.

However, no fiber-optic cables had been laidalong the cable routes, only conventional tele-phone wire pairs. This created a problem, since7SD51 relied on fiber-optic cables or communica-tion networks for transmission, exchanging databetween the devices by means of asynchronous se-rial messages at 14.4/19.2 Kbps.

� The conceptIn mid-2001, a communications converter7XV5662-0AC00 was rolled out for theSIPROTEC 4 differential protection relays 7SD52/ 7SD610. This made it possible for the first timeto transmit synchronous serial differential protec-tion messages with virtually no delay, therebyclosing a technical loophole.

Depending on the cross-section of the pilot wiresthat have been laid, it is now possible to bridgelong distances (see Table 1).

The converter connects to the differential protec-tion relay with noise-immune 62.5/125 µmmulti-mode fiber-optic cables up to a maximumdistance of 1.5 km., with ST connectors at bothends. Two screw terminals connect the pilot wiresto the converter, so there is no need to observepolarity.

FO Differential ProtectionCommunicates viaExisting Telephone Wires

The dielectric strength of the converter with re-spect to the pilot wires is 5 kV. Consequentlyovervoltages induced in the parallel pilot wires byshort-circuits in the cable do not result inflashovers at the converter and so do not impairthe protection function. Voltages as high as 20 kVcan be obtained with external isolation transform-ers 7XR9516.

This made the converter ideal for the applicationin Varel. One further challenge remained: sincethe device was tailored to the application with7SD52/7SD610, it was designed only to transmitsynchronous serial data at 128 Kbps on the pilotwire.

Fig. 1 Varel paper factory

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Data on pilot wires with bridgeable distances for the communication converter

AWG Diametermm

Cross sectionmm2

Ohm/km(0 Hz)

Ohm/km(80 kHz)

Max. distance U ↔ K

10 2.59 5.27 3.38 18.39 38.1

11 2.3 4.15 4.28 20.84 33.6

12 2.05 3.30 5.39 23.55 29.7

13 1.8 2.54 6.99 27.06 25.9

14 1.63 2.09 8.53 30.12 23.2

15 1.45 1.65 10.78 34.21 20.5

16 1.29 1.31 13.62 38.91 18.0

17 1.15 1.04 17.14 44.22 15.8

18 1.02 0.82 21.78 50.64 13.8

19 0.91 0.65 27.37 57.74 12.1

20 0.81 0.52 34.54 66.17 10.6

21 0.72 0.41 43.72 76.18 9.2

22 0.64 0.32 55.33 88.01 8.0

23 0.57 0.26 69.76 101.86 6.9

24 0.51 0.20 87.13 117.73 5.9

25 0.45 0.16 111.92 139.47 5.0

26 0.41 0.13 134.82 159.04 4.4

27 0.36 0.10 174.87 192.88 3.6

28 0.32 0.08 221.32 232.45 3.0

Table 1: Data of standard pilot wires

Resistance with modulation frequency of the converter

Data for a twisted telephone wire pair

The challenge for Siemens Power Automation Di-vision was to expand the existing converter for thetransmission of asynchronous serial data, openingup a broad field of other applications, such as thetransmission of serial protocols includingIEC 60870-5-103/101, DNP 3.0, and MODBUS.Together with the two-channel binary transducer7XV5653, binary signals for comparing the dis-tance or overcurrent-time protection signals couldbe exchanged via pilot wires.

An analysis of the converter hardware and firm-ware showed that this function could be imple-mented successfully on the existing hardware. Theasynchronous transmission function could onlybe implemented in the converter firmware; itcould be developed swiftly within a few weeks.

Tests successfulIn January 2003 the converter with adapted firm-ware was available for the first tests. Long-termlaboratory trials tested the converter with the7SD51 and verified its capabilities. At the asyn-chronous baud rate of 19.2 Kbps, tests recordedno errors in the messages and found 100% reli-ability, typical of transmissions with differential

protection. The message delay with the protectionrelay amounted to only 0.8 ms, which allows acommand time of 25 ms, equivalent to that of adirect fiber-optic cable link.

In comparison, 1996 trials transferring data overdedicated line modems achieved a minimum50 ms command time, with a delay time of 25 ms.This solution also failed to meet the EMC require-ments and therefore could not be used forreal-time protection data transmission over pilotwires. Not until seven years later was a marketablesolution available that allowed protection data tobe transferred virtually without delay.

In May 2003, the converter was released for deliv-ery under the designation 7XV5662-0AC01.




� The special advantagesTransmission over conventional pilot wiresThe converter makes it possible to transfer asyn-chronous, serial data from 300 bps to 38.4 Kbpsover pilot wires without noise interference. Thevalues for the 7XV5662-0AC01, subjected to com-prehensive tests before its market rollout, apply tothe bridgeable transmission distance (seeTable 1) and noise immunity.

Fast commissioningWith the support of the sales and marketing divi-sions, Power Automation Division installed theprotection system (configuration as shown inFig. 2) at the customer’s facility. The 7SD51 pro-tection relays had already been installed, and thebrand new converters were delivered for commis-sioning. The communication converter was con-nected to the protection relay via a short fiber-optic cable, with ST plug connectors attaching tothe converter and FSMA connectors attaching tothe protection relay. The pilot wires were con-nected to the converter. The entire section wascommissioned successfully within a few hours.The protection relay's integrated commissioninghelp functions aided in checking the correct con-nection to the current transformers and to thepilot wires.

Minimum time expenditure for parameterizationCompared to the commissioning of conventionalwire differential protection, the probability offaults and the time taken for commissioning wasreduced considerably. Only three parameters, thecurrent transformation ratios and the measureddelay 0.8 ms, need to be set in the protection relay(Fig. 3). All other parameters could remain attheir default setting. The converter adapts itself tothe serial data rate of the protection relay and onlyrequires the setting of the master and slave modevia a jumper in the relay. This setting needs to bemade for only one relay, which minimizes thetime needed for parameterization.

Fig. 2 Differential protection with communication converter

Fig. 3 Setting parameters in DIGSI

�ConclusionWith a special converter, it was possible to usethe stipulated SIPROTEC differential protectionrelay 7SD51 for the paper factory in Varel andtransfer asynchronous serial data over conven-tional pilot wires. The protection system hasbeen in service since May 2003, to the cus-tomer’s full satisfaction.

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SIPROTEC 7UT635 differential protection forAllgäuer Überlandwerke

� The companyPower for Allgäu – Allgäuer ÜberlandwerkeGmbH (AÜW) is committed to it, supplying elec-tricity to more than 80,000 customers.AÜW considers itself to be an energy service pro-vider, because, in addition to simple delivery, theyoffer customers a variety of services related topower supply.

The starting situationTransformers with phase-angle regulation andregulation in quadrature are used to regulate thevoltage and power flow in power supply systems.These are special transformers. Until now, it hasnot been possible to use 7UT5 and 7UT6 differen-tial protection unless the protection relay wasconfigured to be relatively insensitive. The mea-surement algorithm is designed for a vector groupcompensation of N*300 (N=0,1 to 11) and is pre-set to vector group 0 as per the transformer’s rat-ing plate. The problem is that the transformerwith phase-angle regulation generates an angularshift that deviates from zero.

The transformer with phase-angle regulation (seeFig. 2) comprises a tap changer on side 1 and is re-sponsible for in-phase control.

A sensitive configuration guarantees protectionQuadrature control is performed on side 2 wherean out-of-phase voltage is added to the longitudi-nal voltage of the transformer winding. The over-view in Fig. 2 shows, for example, that a phase L3or L2 transverse voltage is added to Phase L1, de-pending on the tap position of the quadraturetransformer. The amount of transverse voltagecan be controlled, resulting in an angular shift be-tween overvoltage and undervoltage that is nolonger 0 degrees but may be as high as max. ±35°.Because control can be in a positive or negative di-rection as a function of the power flow, significantdifferential currents already result under normalconditions. In the event of a short-circuit, a faultoutside the protected zone can result in an un-wanted operation of the protection relay – even ifthe relay is configured with a rated currentapprox. four times less sensitive than a normaldifferential protection relay.

Everything under control

Fig. 1 Transformer with phase-angle regulation

In Fig. 3, a fault of this type is shown in the pro-tection relay’s tripping characteristic and, with theselected setting, results in unwanted protectionoperation. Configuring the protection relay withan even less sensitive setting would have compro-mised the entire concept of differential protection.

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Fig. 2 Transformer with phase-angle regulation connected to 7UT635

� The conceptFor the purpose of analyzing the problem, thetransformer with phase-angle regulation with itsextensive control range was mathematically simu-lated in the computer. The mathematical modelmakes it possible to calculate the currents onside 1 and side 2 of the transformer. The 7UT635protection relay measures these currents (connec-tion as per Fig. 2). The vector group adaptationand differential protection algorithm are alsomapped on the computer, with the result that thecurrents calculated are used directly as input vari-ables for the protection system simulation. Withthe aid of a test set, the currents calculated canalso be output to a 7UT6 protection relay and fedinto the protection relay at side 1 and side 2 viaanalog amplifiers. This systematic method servesto map transformer and protection system behav-ior.

In addition, the results of the simulation could becompared to faults that the customer has alreadyrecorded by means of fault recorders, thus provid-ing another opportunity to test the model.

The solution was intended to operate without anymodification of the measurement method or ofthe protection relay’s vector group compensation,and to be adapted to the existing device.




Compensation by parameterizationThe task was to compensate for the large phaseangle rotation of the transformer with phase-angleregulation by means of circuitry andparameterization, while taking into account thepositive and negative control range.

For this purpose, the current measured on side 2was fed to two additional input windings in thedevice. Fig. 2 shows the interfacing. The vectorgroup and data for these windings are now config-ured so that the behavior of the phase-angle trans-former can be largely compensated in the device.

SIPROTEC 7UT63 selective short-circuit protectionThe protection relay selected was the 7UT635 of-fering 3 additional windings, 2 of which are used.The transformer with phase-angle regulation isparameterized like a four-winding transformer.Side 3 measures the current for the positive con-trol range and side 4 for the negative controlrange. For the 7UT613/7UT635, the current mea-surement inputs for the sides can be connectedand disconnected via a binary input. This productfeature can be used here to great advantage.

In accordance with the basic solution approach,protection relay parameterization was now devel-oped for the customer's transformer and trans-ferred to the device using DIGSI. Theconfiguration data appears in Fig. 4.

� The special advantagesOptimized for phase shiftingParameterization for the protection relay was op-timized for a ±17.5° phase shift by the phase-angletransformer. For this angle, the longitudinal volt-age to be parameterized for winding 2 and thetransverse voltage to be parameterized forwinding 3/4 can be calculated from the trans-former data to yield a differential current equal tozero. The vector group for winding 3/4 is set to4/8 and optimally emulates the quadrature controlresponse for the operating point selected. Super-imposing the currents measured at the windingsyields a 17.5° phase shift for the operating pointselected. Angles that deviate from 17.5 degrees re-sult in a small differential current that must fallbelow the pickup value.

Testing the protectionThe sensitivity of the protection was configured sothat it would no longer be possible for spuriouspickup to occur at a ±35° phase shift, correspond-ing to a mismatch of 17.5° with the operatingpoint. This is achieved with a setting of 0.6 IN, avalue that still provides adequate security.The result is twice the sensitivity of a conventionalparameterization. The performance of the protec-tion relay can be tested by outputting various

operating and fault scenarios; all important datacan be read from the fault record. Fig. 5 shows theoptimal response to a fault in the tripping charac-teristic, which was still resulting in unwanted op-eration in Fig. 2. Now, high stability with externalfaults has been achieved even with a sensitive set-ting of the differential protection relay.

Fig. 3 Tripping characteristic without compensationof phase regulation

Fig. 4 Parameterizing of windings 1 to 3 (setting for winding 3are valid for winding 4, too)

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Control via binary inputsConnection and disconnection of the measure-ment inputs is controlled via binary inputs. Fig. 6shows the DIGSI 4 configuration matrix with thesignals releasing the measuring points. In a posi-tive control range ( >2(+) ) from 0 to 35°, mea-surement input 4 is released; in a negative controlrange ( < 1(-) ) from 0 to -35°, measurementinput 3 is released. The transfer is by means of sig-nals from the phase-angle transformer tapchanger when the power flow changes from a pos-itive direction (position 2+) to a negative direc-tion (position 1-). In the range from (2+) to (1-),both inputs are blocked and the differential pro-tection operates as a two-winding transformerwith vector group 0.

Fig. 5 Tripping characteristic with compensation of phase shifting

Position 1 (-) Position 2 (+)

�Conclusion:An elegant solution was found by using theSIPROTEC 7UT635 to compensate the largephase-angle rotation of the transformer withphase-angle regulation by means of circuitryand parameterization. A sgnificantly more sen-sitive setting was selected for the differentialprotection thus providing a reliable sensitiveprotection for the complete control range. Thisadvantage can also be applied to all the othertransformers with regulation in quadrature. Theonly requirement is that parameterization beadapted to the object to be protected..

Fig. 6 Control of measuring elements via binary inputs (marshalling in DIGSI configuration matrix)

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Satellite and power line carriers transmit protec-tion data in Peru

� The companyIn Peru, legal requirements call for the strict sepa-ration of power generation companies and powertransmission companies. As a transmission com-pany and former central power system company,ISA (Interconexión Eléctrica S.A.) is responsiblefor the coordination, operation, and administra-tion of the interconnected system for the wholecountry.

� The starting situationThe Siemens regional company in Columbiaequipped six substations in Peru with SIPROTECprotection relays (generations V2, V3, and V4).A PC equipped with DIGSI 4 (Fig. 1) operates therelays from one substation. The core of the systemincludes the PC, passive series 7XV5 converters,and the active mini star coupler 7XV5550, whichmatches the serial data rate for relays of different

protection relay generations. DIGSI 4 directlysupports the setting of these relays, which allowsthe user to easily operate, from one substation, therelays at all the different locations. The user canuse the central system PC to evaluate and admin-ister all data pertaining to a protection relay.

ISA wanted to operate the substations centrallyfrom the station in the capital, Lima, in order toavoid long and sometimes hazardous journeys tothe substations. The plan was to establish a con-nection to the substations using leased lines overspecially installed communication routes. ISA alsointended to implement control functions andvoice transmission over these routes, dividing thebandwidth of 64 Kbps between the different ser-vices. Two substations were linked to the capitalvia leased satellite links (see Fig. 2).

Precise Remote Interroga-tion over Long Distances

Fig. 1 Long distance interrogation for Pucallpa substation




Fig. 2 Substation overview in Peru

One substation is located in Carhuamayo at an al-titude of 4,400 m in the Andes (Fig.2), the other inPucallpa in the middle of the tropical rain forest.Four additional substations are connected to thesetwo substations over distances of up to 140 km us-ing a digital power line carrier (PLC) over an ex-tra-high-voltage line. Siemens PTD EM installedPLC links to transfer data at a maximum rate of76.8 kbps via the high-voltage line. All links ap-peared to be adequate for the transmission of pro-tection data with DIGSI, which is specified with adata rate ranging from 9.6 kbps (V3 devices) to57.6 Kbps (V4 devices).

After installing the system, however, it becameapparent that it was not possible to establish stableconnections to the protection relays, even thoughthe solution worked in theory and the reliabletechnology had been tested. This turn of eventscast doubt on the entire concept of operating therelays centrally from Lima using DIGSI 4.

� The conceptIn order to analyze the fault and to devise a solu-tion, Siemens set up a test system in a laboratoryin Nuremberg, using the same power link system,communications cable simulators, and typicalprotection relays (V2, V3, and V4).

According to the measurements made on the testsystem, the delay over the PLC routes was approx-imately 110 ms. The satellite link added another220 ms delay, resulting in a total delay in one di-rection of approximately 440 ms when a satellitelink and two PLC routes were in series. Because ofthe structure of the serial DIGSI protocol, which isa Siemens-specific expansion of theIEC 61850-5-103 protocol, an acknowledged datapackage between Lima and the remote substationstook about 1 second. This delay, and the gaps be-tween the data, were not planned for in the proto-col and timing concept for either the equipmentor DIGSI, and was preventing a stable high-per-formance link. It was therefore necessary to de-velop and implement a different concept based onthe infrastructure already installed, in order toavoid additional investments.

The Automation division of Siemens A&D pro-vided the solution: the remote control softwarePC-Anywhere, which allows complete control ofremote PCs. The idea was to have the central PCin Lima control the central PC already installed ineach substation. By dialing into each substation’scentral PC, the operator in Lima can monitor theremote station’s status, and can start the locallyinstalled DIGSI from the substation PC.




Fig 3 Communication devices in Pucallpa

� The special advantagesOnce PC-Anywhere was installed, the operatorundertook the first tests from Lima. The local linkto the protection relays functioned. The applica-tion is configured as follows:

� PC-Anywhere establishes the connection be-tween the central PC in Lima to the substationPC via the selected dedicated connection. Thedata is transferred via the satellite link and thePLC route.

� DIGSI 4 operates on the substation’s central PC,which is now completely remote-controlledfrom Lima.

� A connection to a SIPROTEC protection relaywith DIGSI 4 is established. The protection datais transferred at the maximum data rate via theserial links in the substation. Since DIGSI is in-stalled locally, no delays occur.

� Protection data is stored using a quality re-corder in COMTRADE format. Alternatively,all protection data for a device, as well as the en-tire substation’s data, can be stored in a com-pressed Dex file. DIGSI supports this file export,which can be used for the analysis of protectiondata anywhere in the world.

� PC-Anywhere transfers files to Lima; data canbe exchanged between PCs

� DIGSI 4, installed on the PC in Lima, allows forthe importing and analysis of the data files inDIGSI and SIGRA. The protection data can beadministered and analyzed centrally.




� From practical experienceThe test setup in the laboratory made it possible toplan the local installation in minute detail. Thisconsiderably simplified the work of the team oftechnicians from PTD PA 13, PTD EM personnel,the operator, and Siemens Columbia. Given thedifficult travel conditions between the substations– the thin air and icy cold of the installation at4,400 m altitude in Carhuamayo, the tropical tem-peratures in the rain forest in Pucallpa – extensivepreparation in Germany reduced costs andavoided the need for improvisation.

�ConclusionThe customer was highly satisfied with the solu-tion. As a result, Siemens used this solution forfurther substations and implemented completeremote operation of protection relays of differ-ent generations over the communication routes.The operator can now operate substations re-motely and control protection and controlfunctions centrally.

This solution can be used for slow modem linkswith long delays, such as GSM links. In princi-ple, DIGSI can be remote-controlled anywherein the world using a variety of communicationpaths supported by the remote control software.With data transfer via PLC, communication ispossible over long distances, since the high-volt-age line is already routed to the substation. Thismeans that numerical protection relays inremote substations may be operated centrally.Other protection and control functions can beintegrated in the concept and multiplexed bymeans of the common data link (see Fig.3).




Automatic switchover for incoming feeders

� The companyThe customer is a petrochemical company. Thecompany's critical control processes are character-ized by high energy consumption and high oper-ating reliability requirements.

� The starting situationThe project objective was to implement loadtransfer between busbars A and B in a switchgearunit. The customer requested automatic switch-over without interruption, with the followingcharacteristics:

� In the event of undervoltage on busbar A, cir-cuit-breaker CB–QA trips, automatically dis-connecting the bus sectionalizer CB–QC. Thisrestores the power on bus A after a finite inter-ruption time.

� In the event of undervoltage on busbar B, auto-matic transfer is performed in the same way asdescribed above.

� When the power is restored to the tripped in-coming feeder, the associated circuit-breaker(e.g. –QA) has to be closed manually. This isonly permitted through the synchro-check re-lay. The bus sectionalizer CB (-QC) then auto-matically trips, provided the selector switch–S100 is in position –QC.

The requirements of the customer also includedmanual transfer without interruption in the fol-lowing cases:

� In the initial status, incoming feeders A (-QA)and B (-QB) are closed and bus sectionalizer(-QC) is open.

� Undervoltage is detected on one of the two in-coming feeders. The bus sectionalizer can beclosed only when a release command is pro-vided by the associated synchro-check relay.

� After the bus sectionalizer has been closed for acertain definite time, one of the circuit-breakersopens automatically, depending on the positionof the selector switch.

Setting up AutomaticSwitchover

� The conceptThe solution involves control of each circuit-breaker by a SIPROTEC 4 relay. Undervoltage de-tection is implemented as a function inside the in-coming feeder relays. Communication betweenthe relays is hardwired via the relay inputs andoutputs. The information from the selector switch–S100 is forwarded to the relay of the bussectionalizer.

Each relay has been programmed to control itsconnected circuit-breaker and to output com-mand signals to the two other SIPROTEC 4 relays.The automated system also accepts manual com-mands and can operate with a separate synchro-check relay.

�ConclusionThis solution was installed in 2002 and has beenfunctioning correctly ever since. The same solu-tion has also been implemented for 33 kV,6.6 kV, and 400 V switchgear with SIPROTEC7SJ63 and 7SJ62 relays

Fig. 1




Fig. 233 kV 8DB GIS, with CBs protected andcontrolled by 7SJ63

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Fig. 36.6 kV 8BK AIS, with CBs protected andcontrolled by 7SJ63

Fig. 4400 V SIVACON, with CBs protected andcontrolled by 7SJ62

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Malta power plant system solution with dynamicload shedding

� The companyEnemalta, the state-owned utility of Malta, holds amonopoly position on the Mediterranean island.The power supply region covers the entire320 square km island, which lies 90 km south ofSicily, 290 km north of Africa, and almost exactlyequidistant from Gibraltar and Alexandria in themiddle of the countries bordering the Mediterra-nean Sea.

After a colorful history, Malta achieved formal in-dependence in 1964 and final independence in1979, when the last British troops withdrew.

In a referendum, the Maltese decided to join theEuropean Union in May 2004.

The island of Malta is making many investmentsto prepare for its new role in the European Union– including its role as the bridge to North Africa.

� The starting situationSince Malta currently still does not have any con-nections to the mainland and is supplied by onlytwo power stations, it is an island power systemsin the truest sense of the word.

Because the summer of 2003 was extraordinarilyhot, Enemalta was not always able to ensure asteady power supply. The utility needs to expandits capacities and improve operational reliabilityand availability of the Marsa power station.

Malta is made up of stony ground and has fewnatural groundwater resources that could storeprecipitation, which is meager anyway. As a result,the growing need for drinking water can be metpredominantly through desalination plants. Thesevitally important stations account for a major partof energy needs. Other major loads are aircondi-tioners in the tourism industry and in Maltesehomes, shipyards, harbors, and fish processingplants.

Relying on two power stations, Delimara andMarsa, Malta’s power engineering is in a weak po-sition. If one generator fails during peak loads, se-rious network disturbances may occur.

Energy for the Island

� The conceptAs Enemalta makes necessary investments, thefirst step in strengthening the Marsa power plantshould be to modernize the generator protectionwith synchronization and to modernize the twoassociated primary distribution switchgear forpower distribution with appropriate power systemprotection and busbar protection.

Enemalta places great importance on the availabil-ity of the power-engineering parts of the powerplant. In addition to a reliable protection concept,which includes a redundant station communica-tions bus, redundant master units should also beprovided. In the case a generator fails, then loadshedding, prioritized in advance, must dynami-cally balance the decrease in electrical energy toensure the stability of the power system.

Siemens was able to successfully win out over itscompetition through its overall technological so-lution.

Fig. 1 Traditional transportation still exists in Malta, but it is mainly for tourists.

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� The special advantagesSiemens was awarded the contract for several rea-sons, including fulfillment of the specification, thefavorable cost/performance ratio, and our part-nership with the customer. However, the integra-tion of all protection components for thegenerators, busbars, lines, and transformers plusthe network into a complete system was also veryimportant. What also helped was great teamworkwith our colleagues from our Medium-Voltage di-vision from the time the bid was prepared untilthe contract was awarded. The Siemens solutionintegrates components for primary distributionswitchgear, generator protection (7UM62),busbar protection (7SS52), power system protec-tion (7SJ63 and 7UT612/13), and dynamic loadshedding into a complete system.

New dynamic load shedding conceptUltimately, the decisive factor for the awarding ofthe contract was PTD PA’s plan to implement acompletely new dynamic load shedding concept ina power station for the first time. The combina-tion of distributed logic in the SIPROTEC 4 pro-tection and master units and the new calculationprocedure before any fault event makes it possibleto have response times of less than 50 ms for dy-namic load shedding.

Partnership to successDuring the project launch meeting in March 2004,the customer and the Siemens project managersdiscussed open items together and clarified themon site by mutual agreement. Together theyagreed on the new parts and the parts to be ex-panded in the power station.

The launch meeting also included a project orga-nization chart with responsibilities and contacts,as well as a mutually determined schedule withfixed milestones for Siemens and the customer,thus laying the basis for successful project imple-mentation.

�ConclusionBy modernizing the Marsa power station,Siemens is making an important contributiontoward improving the power-engineering infra-structure of new EU member state, Malta,which is on the right path to becoming the hubof the Mediterranean.

Fig. 2 Dynamic load shedding concept




SIPROTEC 4 ensures safe operation of the ThreeGorges hydroelectric power plant

� The projectIn 1992, the Chinese National People’s Congressdecided to build the Three Gorges Dam on theYangtse, Asia’s longest river. Work on the projectbegan five years later in the province of Hubeinear the cities of Sandouping and Yichang, locatedclose to the Three Gorges, with the constructionof the dam and hydroelectric power plant.

In its final stage, the dam will be 185 meters highand 2305 meters wide. The resulting lake willstretch for about 660 kilometers to form theworld’s largest reservoir. The first, partial filling ofthe reservoir began in June 2003, and final com-pletion is planned in 2009.

China intends to meet three objectives with thisproject:

� Generating electric power

� Increasing navigability of the Yangtse (previ-ously limited to only 2,800 kilometers).

� Providing flood control for the entire region

The world’s largest hydroelectric power plantThe final expansion of the Three Gorges powerplant will be designed to supply about 9% ofChina’s entire electric power. 26 turbines and gen-erators with an output of 18,200 MW will be feed-ing power into the nation’s power system. Each ofthe turbines has been designed for an output of700 MW. By the completion of the first sectionlate in 2004, 14 generators were connected to thepower system.

Siemens PTD has supplied many of the primarysystems components. This included for instance14 generator transformers with a nominal capacityof 840 MVA and high-voltage of 550 kV. PTDHigh Voltage Division is also supplying 550-kVHVDC systems for the reliable transmission of theelectric power.

� The starting situationThe construction of a hydroelectric power plant isa continuous technical and logistical challengesince a host of variables must be included in theplanning. The enormous dimensions of thishydroelectric power plant and the enormousforces to be liberated called for solutions that weretailored to this project, especially with regard to

Safety in a New Dimension

Fig. 1 Three Gorges of Yangtse River

Fig. 2 Expansion stage of the dam

safety. The Francis turbine has a diameter of9.4 meters, and water flows through it at a rate of996 cubic meters per second. An entire orchestracould be seated within the generator stator (hav-ing an inner diameter of 18.5 meters). See Figs. 3to 5.

On the other hand, there were also requirementsfor extremely compact designs, for instance of thegenerator transformers. For the Three Gorgesproject, these were produced in Nuremberg andtransported to the construction site by ship.

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Turbine shaft

� The conceptSIPROTEC 4 provided the latest in protectionsystems. These systems protect both the generatorand the generator transformer including thepower system connection. As usual, Power Auto-mation Division supplied the protection cubicles,extensive documentation and the protection set-tings report. The initial shipment for 6 generatorsincluded 12 protection cubicles.

The use of high-performance protection relaysfrom Siemens made it possible to achieve a uni-form redundancy concept and to apply the n-1principle with few relays (2 x 7UM622, 5 x7UT612 and 2 x 7SJ611). Fig. 6 illustrates the basicdesign of the protection concept. The two7UM622s protect the generator and providebackup protection for the generator transformeror the power system (impedance protection orhigh-voltage side overcurrent protection). The

Fig. 5 The generator stator is lowered into position

maximum functionality was selected from theavailable range of functions, and the great major-ity of functions were activated. As a result, eventsthat are reliably detected by the relays includestator earth (ground) faults (90 % and 100 % withthe 20 Hz principle), rotor earth (ground) faults(1-3 Hz measuring principle), short-circuits (dif-ferential, impedance and overcurrent protection),excessive loads (overload and negative-sequenceprotection) and excitation or regulation faults(underexcitation, overexcitation and frequencyprotection). To prevent damage to the powerstation unit resulting from effective power swings,out-of-step protection is also provided.

Two 7UT612 relays provide the main protectionfor the generator transformer and one each7UT612 provides the main protection for the15 MVA station service transformer and for the6.6 MVA excitation current transformer. In therelays for the generator transformer, not only dif-ferential protection but also overcurrent protec-tion is provided at the transformer star-point todeal with high-voltage-side earth faults.

The fifth 7UT612 was additionally provided astransverse differential protection at the generatorto detect winding faults. This protection principleis a special requirement in hydro power genera-tors. To handle the large rated currents (approx.24,000 A) the stator winding for each phase iscomposed of several phase windings. As a result,several rods per phase are located in a single slot.Insulation faults between the rods represent awinding fault, which can cause large circulatingcurrents resulting in enormous damage to thegenerator. Transverse differential protection pro-vides the required sensitivity, speed and stabilityto guard against this hazard.

An alternative, simpler solution is to detect theequalizing current between the two star points ofthe subdivided stator winding. This is provided bythe sensitive earth current function in the 7UM62.This function provides redundancy to the trans-verse differential protection.

Another unique feature of the protection for thepower station unit is the processing of externalsignals, e.g. from the Buchholz relay, oil monitor,SF6 pressure monitor at the bushings, and othersignals related to the machinery. To provide thisfunctionality, these signals were routed directly tothe binary inputs of the 7UM relays.

Fig. 4 Turbine wheel

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The integrated logic functions (CFC) made it pos-sible to provide the required interlocks and logicconnections. An additional benefit of this ap-proach was a reduction in circuitry and elimina-tion of external auxiliary relays.

The different switches must be actuated in accor-dance with encountered fault conditions. The log-ical coordination and required tripping programsare provided through the programmable softwarematrix. As a result, the circuit-breakers can betriggered directly by the binary outputs.

Communications are not included in the illustra-tion. The protection settings and the data readoutsin a fault incident are performed by protection ex-perts using DIGSI directly at the relayss. Messagesand measured values with relevance to the operat-ing personnel are transmitted via PROFIBUS DPto the power plant control system, where they aredisplayed.

� The special advantagesSystems business is teamworkSystems business means delivering systems to thecustomer on time and at the required quality level.This often means that the effort has to be coordi-nated among many different companies,subprojects and individuals. Within Siemens, themain effort is divided among the followingcorporate functions:

Sales and marketingThe protection concept is defined, the requiredprotection relays selected and the entire proposalgenerated to correspond to the customer’s bid in-vitation. The feature that sets hydroelectric powerplants and especially the Three Gorges projectapart is the long implementation time.

As a result, even product development must be in-cluded in the project duration to ensure that thetechnology remains up-to-date. As a case in point,at the outset of the Three Gorges project,SIPROTEC 4 protection relays had just been in-troduced, and the advantages of this technologywere unfamiliar even in expert circles. It wastherefore critically important to meet develop-ment schedules and product quality requirements.

EngineeringDetail work begins after the order has beenawarded. Obviously this includes detailed specifi-cations for the product design and systems config-urations of the components that make up theorder. One detail that had to be confirmed for theThree Gorges project was the design of the currenttransformers. The specific conditions of this pro-ject required an optimum balance in meetingeconomy requirements, space constraints for thecurrent transformer, and dynamic specifications(non-saturated time). The current transformer onthe output side for instance has a transformationratio of 30,000 A to 1 A. To achieve this, 30,000

Fig. 6 Protection concept, single-line diagram




turns had to be accommodated on several coreswithout interfering with the transmission charac-teristics. This challenge was met by designing twolinearized TPY cores in addition to a 5P10010 VA closed core.

Defining the settings was another important partof the engineering project. All setting parametersmust be clearly documented in a settings report.

Given the special features of hydroelectric powerplants and the dimensional constraints of the pri-mary system (for instance in the case of the gener-ator transformers), the accurate detection of alloperational conditions as well as potential hazardscalled for abundant experience. In addition, therequired CFC logic modules needed to be devel-oped and of course tested.

These efforts result in a parameter set generated inDIGSI. The required connection changes (BI, BO,LED, CFC and serial interfaces) must also be im-plemented in accordance with the circuit manual.

Project implementationIn this sphere, the focus is on coordinating all thetasks and resolving any open questions. Specifi-cally, this includes ordering the equipment andcoordinating the delivery schedule with the plant,coordinating the assembly of the cubicles, resolv-ing interfaces, all the controlling, and of coursecustomer support (e.g. during the cubicle accep-tance testing). Project-specific training must alsobe provided for the intended operators to ensure atrouble-free commissioning process.

Since the power station control and protection sys-tems as well as the communications solutions weresupplied by different manufacturers, representativedevices were used in the integration tests. What’smore, a comprehensive test of the entire protectionsystem was performed at the Siemens location inFürth (see Fig. 8). As a result, the integration of theindividual components with the overall system atthe construction site proceeded smoothly.

From practical experienceTo the amazement of all participants, during trialoperation the first actuation of a protection relaywas caused by the 100% stator earth-fault protec-tion. What had happened? During operation ofthe generator another protection relay was active,which was designed to monitor the insulation re-sistance of the stator under operating conditions.This relay caused an earth fault, which was reliablydetected and deactivated by the 100% protectionfunction in accordance with the 20 Hz measuringprinciple.

The tripping on fault provided an opportunity todemonstrate to the customer the effectiveness ofthe protection scheme provided by Siemens, aswell as the benefits of numerical technology. Theinformation stored in the protection made it easyto analyze the fault. Every response of the protec-tion function is logged with milliseconds-accuracyin the fault event buffer, and the momentary val-ues of the analog input values and associated bi-nary tracings are oscillographically recorded in thefault record. The powerful SIGRA tool is used toevaluate the fault record. Fig. 7 illustrates the pro-cessed fault record. Clearly visible are the twospikes in the displacement voltage and in the earthcurrent, as well as a phase-angle shift in the con-ductor-earth voltages. The binary tracings revealthe response of the protection function, showingboth the relay pickup and tripping.

Fig. 7SIGRA printout of the actua-tion of the protection system

�ConclusionDespite the vast scope of this project and thechallenges of integrating components by manydiverse manufacturers, there was no delay in theconstruction or commissioning phase. One rea-son was certainly the unique flexibility ofSiemens technology for electric power unit pro-tection; another the excellent teamwork of allparticipants, such as sales and marketing, engi-neering, project implementation, productionand development, as well as close collaborationwith the construction project.

Fig. 8 Testing the generator protection cubicles LSP2

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Protection and control as a unified system for hy-droelectric power plants of Energie AG Ober-österreich

� The companyEnergy AG Oberösterreich is the leadinginfrastructural company in the Upper Austria eco-nomic region. The company’s core business isgenerating electric power at market prices in anenvironmentally sound way. Generating customersatisfaction through appropriate pricing, supportand services is the company’s foremost commer-cial objective. In addition to its core business, thecompany is also active in the business segments ofenergy services, heat, gas, telecommunications,waste removal and water/sewage.

� The starting situationThe Grossarl power station of Energie AGOberösterreich was built in 1917. It is located inSalzburg’s Grossarl Valley and uses the water ofthe Grossarler Ache River. Two Francis turbinesets are installed in the powerhouse, which wasrenovated in 1966. The two synchronous genera-

High Power StationAvailable and Reliability

tors feed power into the 30 kV busbar system in aunit connection arrangement. From there thepower is fed into the power system via two 30 kVline branches. Fig. 1 and Table 1 provide a generalview of the substation as well as power stationdata.

Fig. 1 Power station overview

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The old protection and control design consisted ofa multitude of individual components, such as re-lays, operator control elements, indicators andtransducers (Fig. 2) that were interconnected bynumerous copper wires and cables.

Machine 1(2)

Turbine Francis

Rated power 3.18 MW

Speed 750 RPM

Generator Three-phase synchronous

Rated power 3.80 MVA

Rated voltage 6.30 kV

Rated current 348 A

Table 1: Power station data

Essential power station components were replacedin 2002. These included electrical and mechanicalprotection relays, machine automation, controlroom equipment and the excitation system. Thismodernization project was designed to include astate-of-the-art protection and control system tomeet present and future needs.

� The conceptElectrical safety of power stations requires protec-tion equipment with a high degree of flexibility andfunctionality. Building on the experience gainedwith V3 relays, an innovative protection system wascreated in SIPROTEC 4 that provides entirely newopportunities of integrating protection and auto-mation functions. Communication viaPROFIBUS-DP provides a trouble-free link withpower station control systems.

In-depth protectionComplete power station unit protection is pro-vided by a SIPROTEC 7UM62 multifunction gen-erator, motor and transformer protection relay.Backup protection is provided by a built-in, trans-former current-fed overcurrent-time protectionrelay with capacitor release (Fig. 3).

The existing Bütow transformer continues to beused for stator earth-fault protection, but the con-trol of the load resistors is now provided by theCFC function in the 7UM62. The Bütow trans-former generates a displacement voltage even dur-ing earth-fault-free operation, so that 100% statorearth-fault protection can be provided withoutadditional equipment.

Fig. 2 Existing switchgear panels with protection relays

Fig. 3Concept of generatorprotection

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Capability of remote operationThe 30 kV lines are protected by a SIPROTEC7SA611 distance protection relay. All protectionrelays are connected to a modem via the RS485service interface (Fig. 4). This linkage provides ac-cess to the full range of DIGSI functionality, suchas changing parameters, reading operational andfault messages, indication of operational mea-sured values etc. even from a remote location. Re-mote maintenance and fast fault correction aregreatly facilitated as a result.

A solid foundation: SIMATIC S7The protection and control system (Fig. 4) isbased on SIMATIC S7. Protection and controltasks of the Grossarl power station are dividedamong three control units that are interconnectedvia MPI bus. A separate control unit is providedfor each machine set and for the general section.One programmable logic controller (PLC) permachine provides the functions of machine auto-mation, mechanical protection and connection ofthe generator protection via PROFIBUS-DP fortransmission of messages and measured values.

Another PLC for the general section controls the30 kV line feeders, provides connection of the lineprotection relays via PROFIBUS-DP, and operatesthe interface to the power station control room(remote control).

Interconnection to power plant control system

Redundant systemTwo touch panels are provided for operation, dis-play of measured values and monitoring (alarmand event lists). Each touch panel can controlboth machine sets as well as both line feeders. Thisarrangement provides redundancy in the event ofa touch panel failure.

� The special advantagesTouch panels provide flexibilityThe use of SIMATIC S7 provided a standardizedproduct for the power station protection and con-trol. Operation by touch panels provides greaterflexibility to accommodate changes and eliminatesthe need to install multiple operator control andindicator devices.

Simplified engineering and commissioningThe connection of the SIPROTEC 4 protection re-lays to SIMATIC S7 via PROFIBUS eliminates theneed for externally mounted measurement trans-ducers as well as for analog and binary inputs tothe PLC. The elimination of these hardware com-ponents also reduces the engineering and com-missioning effort and cost.

This simplification of the installation and wiringalso drastically shortened the conversion phase.




Uniform equipment operationThe uniform protection design with SIPROTEC 4relays is advantageous as it supports uniform op-eration of the generator and line protection andprovides the capability of remote maintenance.

High plant availabilityThe extensive self-monitoring of the system com-ponents results in substantial improvement inplant availability and reliability.

�ConclusionA cost-optimized, state-of-the-art protectionand control system was implemented during themodernization of individual power stationcomponents at the Grossarl power station ofEnergie AG Oberösterreich.Of great advantage were not only the trouble-free integration into the power station controlsystem but also SIPROTEC multifunction pro-tection relays' compact design.



Power Quality

Quality recording in static VAr compensators SVC

� The companyThe shareholders in Baltic Cable AB, founded in1991, are the Norwegian power supply companyStatkraft, the E.ON energy services group, and theSwedish company Sydkraft.

� The starting situationSince 1994, Baltic Cable has exchanged electricitybetween Germany and Sweden by means of a250-kilometer-long (160 miles) direct-currentlink. The 450 kV high-voltage, direct-currenttransmission system (HVDCT) has one converterstation in Kruseberg and one in Herrenwyk. TheHVDCT system was designed with a transmissioncapacity of ± 600 MW. Contrary to original plans,however, the system is now linked to the 110 kVpower system, because of changes in the Europeanenergy market. In order to guarantee dynamic op-eration of this transmission cable, despite theconsiderably lower short-circuit power at thisvoltage level, E.ON is undertaking various expan-sions based on a network study.

The corresponding 400 kV transforming station,in direct proximity to the HVDCT converter sta-tion, connects to the 220 kV transforming stationin Lübeck via a 10 km long cable. E.ON ordered a380/220 kV transformer with a rating of 350 MVAfrom Siemens, which is required for the Siems sta-tion.

� The conceptA static VAr compensator (SVC) is being installedto guarantee the voltage quality. Since theHVDCT converter station has a high dynamicperformance, the compensation system needed tohave at least the same dynamic performance. Tostabilize the system voltage in case of a change inthe power transmitted over the HVDC cable, thesystem had to provide equivalently high inductive(voltage reduction) or capacitive reactive (voltageincrease) power. In order to implement these reg-ulating processes quickly, the SVC relies onhigh-speed power electronics systems.

When completed, the SVC will consist of a three-phase 400/18 kV transformer, which links to thetransmission system at the Siems transformer sta-tion, and four subcomponents installed in the18 kV area.

Good Connectionsbetween Sweden andGermany

Fig. 1 Quality recording in static VAr compensator

� The special advantagesThe four subcomponents of the SVC system covera control range from +200 to -100 MVar for thevoltages and times described in the specification.

Inductor is infinitely variableOne of the four medium-voltage components is apower-thyristor-controlled reactor. The reactor(reactance coil) generates an inductive current.Since the reactor is the only infinitely variable unitconnected to the power electronics system, it isdesigned to cover the entire control range of theSVC system, from +200 to -100 MVar.

SIMEAS R



Power Quality

Capacitor unit generates reactive powerThe second component is a capacitor unit. Thesystem section can be switched in or disconnectedvia the connected power electronics system so thatleading reactive power can be generated if needed.

Reactive power generator serves dual functionsThe third and fourth units are leading reactivepower generators. They also double as filters inorder to avoid any harmonic feedback in the SVC,and are therefore permanently connected.An equipment building houses the power elec-tronics system and the control and protectionequipment that operate the system.

SIMEAS R guarantees reliable voltage qualityIn order to log the correct functioning of the SVCsystem with the corresponding power system re-quirements and to determine the cause of anyfault, the protection and control concept includesa SIMEAS R quality recorder. The availability ofthe SVC system is a condition of the commercialcontract, and Siemens had to provide proof ofavailability. At the same time, a high degree of re-cording accuracy is important, since the SVC con-trol is designed to operate at an accuracy of betterthan 0.5 % in order to guarantee the voltage qual-ity.

The quality recorder provided in the Siems SVCrecords the primary voltage and currents on the400 kV side. It also records the reactive power andthe harmonic voltages on the primary side, thevoltage on the transformer secondary side, thecurrents of the individual medium-voltage com-ponents, and various protection and control sig-nals.

Data analysis and archivingFor analyzing and archiving data, an evaluationstation is connected to the SIMEAS R. The substa-tion includes a PC equipped with OSCOP P soft-ware and a printer.

�ConclusionQuality recording in the SVC documents thepower quality. Due to the recording of the cor-rect functioning of the SVC, it is possible to eas-ily and quickly locate a fault and its cause.The data base of the SIMEAS R is the basis forthe commercial contract. It serves as a proof forthe availability of the plant.

Fig. 2Example of a quality record

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Power Quality

Fault recording for HVDC transmission systems

� The companyTwo power supply companies have joined forcesto build a bridge between Northern Ireland andScotland by means of the Moyle DC Inter-connector. In order to meet rising energy de-mands, Northern Ireland Electricity (NIE) had toexpand its 275 kV three-phase system in NorthernIreland. Scottish Power, Scotland's national powersupply company, provided the connection to theScottish three-phase system.

� The starting situationThe exchange with Scotland proved to be the mosteconomical, safe and ecological solution for ob-taining the necessary power. The Moyle transmis-sion project will enhance the security of supply tothe Emerald Isle while also improving NIE’s com-petitive position.

This HVDC interconnection, known as the MoyleInterconnector, is a dual-monopole system. Eachof the 250 MW poles is designed for bi-directionalpower transfer. Two submarine cables through thechannel will bridge the 64 km gap between Scot-land and Ireland.

Each converter station has a rated power of250 MW at 250 kV DC. The HVDC thyristorvalves are equipped with direct-light-triggeredthyristors with integrated overvoltage protection.

� The conceptFor this project, Siemens Power Transmission andDistribution supplied electronic equipment in-cluding a number of SIMEAS R fault recorders forthe two converter stations located at Auchencroshin Ayrshire (Scotland) and Ballycronan More inCounty Antrim (Northern Ireland).

Moyle Interconnector -Forming a Bridge betweenGreat Britain and Ireland

Fig. 1 HVDC power station in Ireland

Fig. 2 "Moyle Interconnection" between Scotland and Northern Ireland

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Power Quality

� The special advantagesFast on-site analysisEach station contains several SIMEAS R ZE32/64recorders with various recording modules(DAUs). The SIMEAS R recorders are connectedto the local evaluation station via an Ethernet in-terface. Each local evaluation station comprises aPC, local printer and modem, providing for fastonsite analysis. It is also possible to simulta-neously transmit the data to a higher-level evalua-tion station automatically via the telephone line.In the event of a fault, the SIMEAS R recorders arestarted by a network trigger and serve to record allanalog and binary signals.

Data evaluation and archivingThe evaluation station and server PC are availablefor evaluating, analyzing and archiving the faultrecords. The OSCOP P system program is in-stalled on the individual PCs and providesautomatic remote data transmission, archivingand diagnostic output of measured-value files.The OSCOP P software is also used forparameterizing SIMEAS R and has extensive cal-culation, filter and statistics functions.

Data from the individual SIMEAS R fault record-ers is retrieved and stored on the individual PCs.These PCs operate with OSCOP P in automaticmode, meaning they automatically retrieve thefault records from the individual SIMEAS R re-corders and automatically store them in theOSCOP P data base.

One device-many functionsWhen a fault occurs, SIMEAS R records and doc-uments all DC and AC values, as well as individualbinary values such as trips, HV breaker positionsand critical alarms. It also records and documentstests. But this isn’t all SIMEAS R can do: It pro-vides commissioning tools for optimally configur-ing protection and control, plus it generates faultlogs for tracing the causes of plant failures and, ifappropriate, implements preventive measures.

Fig. 3 Configuration of the fault recording systems



Power Quality

� From practical experienceSIMEAS R Records

Fig. 4 Example of SIMEAS R record


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Power Quality

�ConclusionThe Moyle Interconnector links the power sup-ply systems of Scotland and Northern Irelandusing an HVDC interconnection, thereby im-proving the stability of the power supply inNorthern Ireland. SIMEAS R digital fault re-corders are also used. Their numerous functionspermit a fast and reliable identification of weakpoints using only one device.


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Power Quality

Fault recorder system at CERN

� The companyCERN (“Centre Européenne de RechercheNucléaire”) is the most important European orga-nization for nuclear research and is financed by 20member states.

CERN has been responsible for important discov-eries within the microcosm of the smallest parti-cles. To make such research possible, CERNoperates several particle accelerators requiring alarge amount of energy.

� The starting situationOn the French side, CERN is supplied with electri-cal power by EdF – RTE (400 kV) and on theSwiss side by EOS. They also receive emergencypower from the 16 kV power supply system ofSI Geneva. In addition, CERN operates internalemergency generator sets. Power is distributed in-ternally via the Prévessin station by means of a16 kV ring. According to their own indications,CERN operates approx. 7000 medium-voltagecells.

The quality of the power supply is extremely im-portant. Any fluctuation or fault can falsify re-search results and delay research projects formonths.

No possibility of integration into the telephonenetworkIn the past, CERN relied on the fault recordingsystems at the individual power supply points forobtaining the necessary data in the event of apower failure. Fault recorders from various manu-facturers are used, including SiemensOSCILLOSTORE systems operated autonomouslyat 5 infeed stations. Integration in the customer’sown telephone network was planned, but the net-work proved obsolete and could not safely be usedfor a reliable transmission of fault data.

Time-intensive evaluationWhen a fault occurred, technicians had to drive toa station before they could access the data andstart analysis. This evaluation method, which haddeveloped over time, was time-intensive andhighly inefficient. Because the fault recorders usedcame from different manufacturers, it was notpossible to combine data in a single system soft-ware.

Reliable Research

Fig. 1 CERN member states

CERN’s requirement: All data must be concen-trated and analyzed centrally.

� The conceptSiemens Power Automation Division developed asuitable concept that permits centralized evalua-tion without necessitating the replacement of ex-isting devices. As a further advantage, theproposed solution allows a future system expan-sions.

Centralized dataThe solution serves to concentrate the data at thecustomer’s head office. This placed special de-mands on the communication concept. It was thecustomer’s requirement that no additional elec-tronic components are to be installed in the parti-cle accelerators, because they might falsify theresearch results.

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Power Quality

The old fault recording systems were adapted tothe new communication options. This required apartial replacement of the firmware as well as are-parameterization.

� The special advantagesEasy to expandThe Siemens concept permits the cost-effectiveand user-friendly integration of potential expan-sions. In addition, the DAKON 98 system usedmakes it possible for a higher-level office to accessthe recorded and stored data.

CERN considers this future-oriented concept tobe the ideal solution. They eagerly promoted theconversion and also replaced the non-Siemensfault recorders with SIMEAS R.

Flexibility in data synchronizationAn evaluation station that can be set up at a sepa-rate location was connected to DAKON 98. At thisstation, data synchronization can be performed ei-ther manually or automatically and more exten-sive fault analyses can be conducted using theOSCOP P system software.

Future-proof systemCERN plans to expand the current fault monitor-ing system to include power quality analysis withSICARO PQ. They must also be able to includedata from other users in the analysis, which re-quires converting to a client-server system archi-tecture. This conversion can easily be performedusing the OSCOP P system software.

Fig. 2 CERN, schematic diagram

Connection via interfacesThe device located furthest from the head office isabout 14 km away. The demands on the commu-nication links could be met only by employingmono-mode fiber-optic cables (1320 nm). Theold-model fault recording devices currently in usewere not bus- or network-capable. A point-to-point connection to a star configuration had to beset up for each device to provide a sufficient num-ber of serial interfaces at the data collection center.

The solution implemented includes a DAKON 98data concentrator at the customer’s head officewith an appropriate number of serial interfaces. Itwas possible to integrate all existing Siemens faultrecorders in a global concept by means of convert-ers connected to 1320 nm fiber-optic cables. Fig. 5provides a detailed diagram of the communica-tion link.

�ConclusionA fault recording system was installed at CERN,permitting the concentration and analysis of alldata and making it possible to take fast and ef-fective action in the event of a fault. This is ex-tremely important to CERN, because theirresearch work cannot be safely conducted un-less high power quality is guaranteed. More-over, future system expansions are possible andeasy to implement.

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Power Quality

Fig. 4 Enhanced fault recording system of CERN

Fig. 3 Technical configuration before modernization

Fig. 5 Schematic diagram of a communication link

1) Communication link, details see Fig. 5



Power Quality



Power Quality

Fault analysis in Zurich using fault recorders andprotection relays

� The companyPower production, transport and distribution – asone Switzerland’s few power companies,Elektrizitätswerke Zürich (ews) (Zurich electricityutility) offers all three from a single source. ewzsupplies power and provides all related services,not just to Zurich but to about a third of theKanton Graubünden; altogether, the company de-livers power to approx. 240,000 customers, mak-ing it one of the 10 largest power stations inSwitzerland.

The majority of ewz’s power is generated by hy-droelectric power plants in Graubünden and onthe Limmat River. Using a power systems of over700 kilometers of extra-high voltage overheadlines, power is fed via various nodes fromGraubünden to the four connecting substationson the outskirts of Zurich, and from there is dis-tributed via a 4000 kilometer cable system to the17 substations in the various districts. These sub-stations are connected to 670 transformer stationsthat supply power to all private and commercialcustomers as well as public facilities and munici-pal lighting.

Maximum Successthrough MinimalDowntimes

� The starting situationEvery fault that occurs in the power supply systemof a large, densely-populated city with corre-spondingly high energy requirements is a majorchallenge for municipal utilities companies. Ev-eryone affected wants to know as quickly as possi-ble when and how power supply will be restored.

Quick assessments are especially difficult to makebecause today, the protection relays and fault re-corders installed in most of the switchgear ofmany power supply companies came from differ-ent manufacturers. This problem is compoundedby the fact that in a large number of cases, differ-ent technologies were also installed (such as elec-tromechanical and numerical protection relays)that frequently belong to different generations(such as SIPROTEC 3 and 4 relays).

The result: A single power system fault suffices totrip several protection relays simultaneously.Whether one or more protection relays are trip-ped depends on the type of fault. Resolving thefault sometimes involves starting up operatingsoftware (such as DIGSI) from different manufac-turers , retrieving the data from the IEDs (Intelli-gent Electronic Devices) and performing acomplete analysis.

Fig. 1 Server PC configuration and the number of connected devices



Power Quality

� The conceptZurich needed a solution that would make theevaluation of fault logs as quick and easy as possi-ble. In the present case, ewz was able to achieve anextremely intelligent and effective result by install-ing the Network Quality Analysis System (NQS),which can reduce fault resolution time to less than30 minutes and usually to as little as 15 minutes.The complete system, which monitors the greaterZurich area, includes 8 high-capacity servers,

400 fault recorders (SIMEAS R and P531),250 numerical protection relays and 50 SIMEAS Qpower quality recorders. These are supplementedby 50 additional devices (40 P531 and 10SIMEAS Q) belonging to other power supplycompanies but whose data is also analyzed by ewz.

� Function of the NQSEvery ewz substation has at least one DAKON towhich some or all of its IEDs are connected. ADAKON is an industrial PC with the OSCOP Psoftware program that automatically retrieves thefault data recorded by the IEDs and stores it in aseparate data base.

All of ewz's DAKONs are connected to the centralserver (see Fig. 1) via two independent communi-cation channels (Ethernet and telephone, makingit a redundant system), thus ensuring that all750 devices belonging to ewz are indirectly con-nected to the main office. The OSCOP P softwareprogram also runs on the server PCs shown inFig. 1. This program automatically retrieves all the

data on the connected DAKONs and stores it in aseparate data base.

Additional OSCOP P modules analyze the data, sothat station engineers are presented only with thefinished report. The servers are able to make thesereports available on the Internet or Intranet inHTML format. Depending on parameterization,the reports can also be forwarded to individuals byfax or e-mail. In special cases, supervisors can alsobe instantly notified by SMS (text message).

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Fig. 2 Distribution system of ewz



Power Quality

� The special advantagesThe NQS is the only system in the world to pro-vide a special feature known as “complex analy-sis”. The OSCOP P system program sorts all therecords in a time window and uses various meth-ods to calculate fault locations. After several itera-tions, the location of the first fault is finallydetermined and all the consequences identified,meaning significant time savings because thestation engineer does not have to perform theanalysis manually. One advantage of this directidentification of the original fault is that the unaf-fected service sections can be started up immedi-ately. A further benefit is faster fault correction,making it possible, for example, to minimize theproduction downtimes of an industrial plant.

� From practical experienceAs shown in Fig. 3, the NQS analyzes all the faultrecords and power quality data from the con-nected IEDs. Thus, for example, a productionfault in an industrial complex can be located. Inthis case it is caused only by voltage dips provokedby a short-circuit in another power system sec-tion.

�ConclusionThis project involves the world’s first fault anal-ysis system with automatic data collection, dataanalysis and report distribution. These innova-tions are beneficial, not just to ewz, the powersupply company, but to the entire region. Fasterfault correction saves the operator money whiledrastically reducing downtimes for local indus-try.

Fig. 3 Data flow for fault evaluation



Power Quality



Power Quality

Fault and power quality recording at Pfalzwerke AG

� The companyEstablished on December 17, 1912 as a small util-ity, Pfalzwerke AG is nowadays the number oneenergy provider in the Pfalz and Saar-Pfalz re-gions. Pfalzwerke AG supplies power to about280,000 private and 1500 commercial customersover an area of 6000 square kilometers that in-cludes over 8000 kilometers of power lines andabout 4000 substations.

To cope with the constantly growing demands onthe power supply, strict environmental regulationsand rising energy costs, new methods and technol-ogies are needed. Pfalzwerke AG has recognizedcurrent trends and invests more and more in newtechnologies and solutions so that they are able toprovide electrical energy in a proper way. Regen-erative power sources such as wind power andphotovoltaic systems, among others, are increas-ingly being employed to generate power. Never-theless, the use of these technologies as well asderegulation have placed special demands on theoverall power supply. Through area-wide moni-toring of the power supply, it is possible to de-termine problems and their causes and to initiatethe proper measures to clear them. Among otherthings, the recording and analysis of power qualityaccording EN 50160 plays an important part.

� The starting situationIn preparation for future challenges, a joint solu-tion was developed for the area-wide monitoringof network quality. The goal of this project was tointegrate the fault recorder system intoPfalzwerke’s communication network in such away that data should be transferred exclusively viathe corporate WAN. This wide-area network has aspecial feature: All data transfer is performed inparallel, including the Internet, Intranet, MS Of-fice applications, Voice over IP (phoning viaTCP/IP), data communication by the fault re-corder, PQ monitoring, etc. In the case of measur-ing points that cannot be connected to the WAN,data will primarily be transmitted via GSMmodems.

Uniform Power QualityRecording via a Wide-AreaNetwork (WAN)

� The conceptA special implementation concept was developedbased on the large volume of data (fault recordsand mean values). It is integrated in the commu-nication network such that, on the one hand,time-critical fault records can be transmitted andanalyzed as quickly as possible and, on the otherhand, no interferences with any of the other ser-vices operating via the WAN can occure.

Fig. 1 Web page of Pfalzwerke

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Fig. 2 Service area of Pfalzwerke AG

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Power Quality

�On-site testsIn order to guarantee the performance of the solu-tion developed, operating scenarios were jointlydesigned with experts at Pfalzwerke AG and thentested on the customer system. The tested featuresincluded the transmission speed of fault recordswith simultaneous restriction of the communica-tion bandwidth.

� Time-optimized analysisThe SIMEAS fault recorder and the OSCOP Pprogram for retrieving and processing recordsprovide area-wide monitoring of power quality(PQ). Integration of the power quality recorder inthe corporate WAN permits the time-optimizedanalysis of faults in the power supply and the im-plementation of countermeasures to clear them.

� Fault record transmissionThe SIMEAS R fault recorder and PQ monitoringsystem are set up so that one SIMEAS R 16/32with the maximum configuration (4 VCDAUs) isinstalled in each substation and linked to theWAN.

Each SIMEAS R is connected to the communica-tion network via the internal network card.SIMEAS R fault recorders are parameterized incallback mode. This means that after a fault is re-corded, a call is placed to the appropriate serverand the fault record is transmitted.

� The special advantagesData collection and server operation – centralizedorganization, decentralized executionData collection, i.e. the retrieval (gathering) andstorage of data from the individual SIMEAS Rfault recorders, is organized centrally. The data isretrieved by 8 servers that are installed in onestation and connected to the WAN.

To ensure the highest degree of operational reli-ability, the server hardware is based on currentlyavailable technology. This means high computingpower, a large RAM and, above all, a redundantstorage system with backup functions.

Division of labor among eight serversTo make the transfer of fault records from aSIMEAS R recorder in the bay to the appropriateserver in the station as fast as possible, the faultand mean value records are retrieved and distrib-uted separately to the different servers. In concreteterms, this means that 4 servers are used exclu-sively for retrieving and storing fault records and 4servers are used exclusively for retrieving mean

value records. This ensures that the retrieval of afault record will not be blocked by a simultaneousmean value record retrieval. In addition, sufficientstorage space is available for the recorded values inthe OSCOP P data base on the individual servers.

Automatic data retrieval and storageThe individual servers operate with OSCOP P inautomatic mode. In other words, the servers auto-matically retrieve the fault and mean values fromthe individual SIMEAS R recorders and automati-cally store them in their data base.

Collection of mean values – easily implementedusing PCsPCs running OSCOP P in DAKON mode collectmean values from the individual SIMEAS Qmean-value recorders. They query the individualSIMEAS Q recorders via modems. At the otherend (SIMEAS Q side), GSM modems are used.

Evaluation – when and where you want itThe fault records are evaluated by means of evalu-ation PCs connected to the server system via LAN.These PCs can be connected anywhere in the com-munication network, which also ensures thatSIMEAS R can be parameterized from any pointin the communication network. Whenever neces-sary, the evaluation PCs access the individual serv-ers and retrieve the fault records for purposes ofanalysis.

Any number of OSCOP P clients can also be in-stalled in the communication network. Theseclients have only read-access to the fault datastored in the servers. The system and devices can-not be parameterized from a client. This has theadvantage that each user can access the data he orshe needs.



Power Quality

� System overview� One SIMEAS R is installed in each substation

and transfers its fault records and mean valuesto a central server via the WAN. In the maxi-mum configuration, up to 60 SIMEAS R re-corders can be connected to the system formonitoring the 110 kV and 20 kV level.

� Four servers (fault recording) are installed forhandling SIMEAS R fault records and anotherfour servers (PQ) for retrieving the mean valuesfrom the SIMEAS R and SIMEAS Q recorders.

� Most of the SIMEAS Q recorders are connectedto a DAKON PC via a GSM modem. The PCtransfers its mean values to the central mean-value servers. In the maximum configuration,up to 30 SIMEAS Q recorders can be connectedto the system.

� Evaluation PCs are installed in the WAN for an-alyzing the fault and mean value records.

� SICARO PQ is operated in automatic mode forthe purpose of analyzing power quality.



Power Quality

�ConclusionCompetent support and consulting provided bythe Siemens Power Transmission and Distribu-tion staff – from the design phase to rollout –guaranteed Pfalzwerke an optimal solutionbased on the customer’s requirements.

The particular challenge of this project was tointegrate the fault recorders into an existingWAN. The most important consideration wasthe amount of time it took for a fault to occur,be recorded, be transmitted and, finally, for thefault record to appear on the screen. Based onthe tests performed on the customer system, allparties came to have full confidence in the per-formance and reliability of the solution offered.

The SIMEAS R and OSCOP P fault recordingsystem provides Pfalzwerke AG with a uniformsystem for monitoring and analyzing powerquality. In addition, its modular design sets nolimits on future expansions.



Power Quality

Monitoring the data center of the DEVK insurancecompany in Cologne

� The companyDEVK is one of the largest insurance companies inGermany, offering all types of insurance policiesas well as investment services for real property andsecurities. Over three million customers in Ger-many rely on DEVK’s services.

� The starting situationAll the company’s business processes converge inthe central data center in Cologne, where infor-mation is stored and evaluated. DEVK has en-gaged Siemens PTD Power Automation Divisionto protect the company's servers and backup sys-tem from failure of the power supply.

� The conceptContinuous power supply is ensured by SIMEAS R,a system developed by PTD Power AutomationDivision. If the municipal power supply fails, anuninterruptible power supply (UPS) with two re-dundant 125 kVA battery banks initially providespower to the server. At the same time, a dieselgenerator starts, which normally takes over thefull load within 60 seconds.A special device monitors the charge state of thebatteries of the UPS system, allowing users to de-tect problems with the batteries early and takecountermeasures quickly.

Installing a digital fault record system withSIMEAS R is ideal for documenting all power sup-ply problems that occur during operation.SIMEAS R can continuously measure and log thecourse of voltages and currents at the medium-voltage level (10 kV) and also at the low-voltagelevel at the output of the UPS system. The systemcan record exactly the effects of external short-cir-cuits near the location, and analyze the impact ofthe resulting voltage dips on the UPS system. Italso monitors the UPS system to determinewhether every changeover from the outside supplysystem to the UPS system takes place withoutinterruption.

Intelligent TechnologyProvides Optimal DataSecurity

Fig. 1 Block diagram of installed UPS and emergency generator

Fig. 2 Diesel generator at DEVK

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� The special advantagesTask distribution according to competencesOne of the technicians’ tasks at DEVK is to keepthe data server and the backup systems runningsmoothly. However, the technicians can neithercontrol the quality of power supply from the mu-nicipal utilities company nor the UPS system. An-alyzing the data from the SIMEAS R requires agreat deal of experience, which the DEVK engi-neers do not have yet and – due to cost-relatedreasons – do not plan to build up.

In response, DEVK hired ewz (ElektrizitätswerkeZürich, Zurich electricity utility ) to take over ana-lyzing the SIMEAS R data. This arrangement al-lows each partner to concentrate on its ownstrengths, creating a real "WIN-WIN" situation:ewz retrieves the SIMEAS R data using a modemconnection, while DEVK continues to retrieve thesame data via the Ethernet interface and store iton its own PC. As a result, the DEVK technicianscan concentrate on rapid fault clearance, whileewz analyzes the data to determine the exact causeof the fault. ewz provides its reports to the DEVK

technicians immediately. According to all partici-pants, only the fault recorder system "SIMEAS R +OSCOP P" met the necessary technical require-ments.

�ConclusionSIMEAS R made it possible to ensure perma-nent monitoring of the power supply, guaran-teeing and protecting the functioning ofDEVK’s data bases and the data center. Distrib-uting the tasks according to expertise not onlybrought about quick and smooth commission-ing of the system, but also reduced DEVK’scosts significantly.

Fig. 3 DEVK data center

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Power Quality

Area-wide fault recording using state-of-the-arttechnology

� The companyAs the largest power supply company in the regiondelivering power to the greater Nuernberg area,N-ERGIE supplies electricity to about 650,000customers. Each year, N-ERGIE provides an aver-age of 7,300 million kWh of power to a 7,500 km2

service area.

� The starting situationAs an operator in its service area, N-ERGIEneeded a state-of-the-art, cost-effective methodfor recording faults in order to ensure reliablepower system management. Because the hardcopyrecorders currently in use were both maintenance-and labor-intensive, N-ERGIE was looking for afuture-oriented fault monitoring system. Theyhad complete confidence in the expertise andtechnology of Siemens PTD Power AutomationDivision.

� The conceptThe only way to efficiently reduce maintenanceand operating costs is through the automaticmonitoring of power transmission equipment. Toensure reliable power quality monitoring for theentire service area, N-ERGIE will employ 48 digi-tal SIMEAS R fault recorders and 35 existingOSCILLOSTORE P531 fault recorders in the me-dium- and high-voltage power systems. In addi-tion, state-of-the-art recording technology willsupport research into the causes of faults and fail-ures in the power supply system.

� The special advantagesDetection of power anomaliesDetailed fault records can now be used to obtainadditional, important information on the faulthistory, even in the case of complex error profiles,thus permitting targeted research into the fault’sorigins and providing a basis for effective preven-tion.

Support for fault clearanceInformation supplied by the recording system di-rectly supports fault clearance experts in localizingthe fault. Resultant costs are significantly reducedwhen the location and origin of a fault are quicklypinpointed.

Moving Securely into theFuture

Fig. 1 Service area of N-ERGIE

Load forecastsThe mean-value recorder generates daily, weeklyand even annual load curves. The values derivedcan serve to generate a much more precise forecastfor the future – a money-saving advantage whenpurchasing power.



Power Quality

Protection monitoringOlder substations in particular still have protec-tion relays without fault recording or withoutlong-distance transmission capability. Any infor-mation on the cause and history of the fault iscompletely lost. In such cases, SIMEAS R record-ings may be used to verify the correct functioningof the protection relays, e.g. correct tripping be-havior/tripping time of the relays.

Additional benefits are achieved by swapping outfault records to the COMTRADE format. Thisgeneral standard makes it possible, for example, toperform additional tests using Omicron testequipment. Analyses from the fault records alsoyield important information for optimizingequipment.

Four integrated recorder functions and decentral-ized data storage mean faster access to all essentialdata in the event of a fault. Only SIMEAS R canhandle such high volumes of data, thanks to itsdata compression procedure. And excellent sys-tem integrity ensures that the extreme ambientconditions under which power is supplied are al-ways taken into account.

� From practical experienceThis section describes the sequence of events andexact fault detection process for a complex faultrecorded by an OSCILLOSTORE P531. A single-phase-to-earth fault on L3 developed into a two-phase-to-earth fault between L2 and L3:

Fig. 2 Fault record of a complex disturbance

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Procedural description1. Background: Single-phase-to-earth fault on L3,

U3E suffered a near total breakdown, U1E andU2E increased by the cube root to approx.21.3 kV. The displacement voltage UNE rose to12.5 kV.

2. A two-phase-to-earth fault between L2 and L3was added (time on trigger line Tr), short-cir-cuit current approx. 4.7 kA. Both the electrome-chanical distance protection (overcurrenttripping) in the relevant outgoing feeder inbay 12 and the higher-level numerical distanceprotection (impedance tripping) in the incom-ing transformer feeder in bay 10 were tripped(see binary traces).Feeder protection was tripped instantaneously(approx. 140 ms) and reclosed automatically(duration approx. 460 ms). During this time,the short-circuit current was interrupted andonly operating current continued to flowthrough the remaining system (approx. 400 A).

3. Auto-reclosure (AR) was followed by automaticconnection. However, the fault was still present.Both the feeder protection and the higher-leveltransformer distance protection were re-tripped(see binary traces).The outgoing feeder was then instantaneously(approx. 120 ms) and finally tripped (failed AR)– see binary trace protection AUS of the loopfeeder (LF).This fault recording system is the best way totest the functioning of the electromechanicalprotection system.

�ConclusionLightning-fast detection and correction of faultshas not only increased end user satisfaction buthas also saved N-ERGIE money. Unique prod-uct features such as automatic data transmis-sion and system management, the advantages ofa high sampling rate and resolution, and thehigh-quality, user-friendly software for fault re-cords have all contributed to the complete suc-cess of SIMEAS R. The extensive expertise of theSiemens project managers was decisive inachieving the high degree of customer satisfac-tion.

Fig. 3 Example of a fault record

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Power Quality



Power Quality

The fault and power quality recording system atCFE

� The companyThe Comisión Federal de Electricidad (CFE) is astate-owned utility in Mexico. It is responsible forgenerating, transmitting, and distributing electri-cal energy for over 21 million customers. CFE alsoallocates energy to regional power distributioncompanies such as Luz y Fuerza in the MexicanFederal District.

Because of undefined power system disturbancesand limit violations, CFE operates an extensivepower quality system. This system stretches fromthe northern Baja California Peninsula region tothe southern Yucatan Peninsula region.

� The starting situationCurrently, CFE has an equipment pool of 173 dig-ital fault and power quality recorders (SIMEAS R),40 fault recorder systems (OSCILLOSTOREP531), and 4 data concentrators (DAKON). Todate CFE has operated the installed fault recordersin off-line mode.

Operating the fault recorders in isolation requireseach CFE agent to have a laptop with its ownOSCOP P license, resulting in many single-user li-censes and thus higher costs. Data transfer takesplace manually and remote data transmission isnot available.

Quality in the PowerSystem

Fig. 2 Overview of the CFE regions with an installed SIMEAS R digitalfault and power quality recorder

Fig. 3 Fault recorder in off-line mode operation

Fig. 1 CFE at a glance

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Power Quality

� The conceptCFE and Siemens Mexico collaborated to developa concept that met the following requirements bythe customer:

� Quickest possible fault analysis

� Central data management

� Central parameterization

� Integration into the existing communicationsinfrastructure

The challenge was to install 16 analog channels(8U/8I) in one central unit – a special requirementinfluenced by the American competition.

Automatic data collection and processingThe fault records of the analog and binary chan-nels are recorded in the individual systems by thefault recorders (SIMEAS R) and automaticallycollected and processed in a data concentrator(DAKON).

Flexible accessThe DAKON is an industrial PC to which severalSIMEAS R and numerical protection relays can beconnected. The fault recorders can connect toDAKON using either fiber-optic cable or a LAN.The DAKON also provides the option of remoteaccess from regional evaluation stations. Normallythis access relies on the communications structurethe customer provides, which in most cases con-sists of an analog telephone network (see Fig. 4).

Real-time synchronization via GPSIn the DAKON, parameters (OSCOP P software)define which information from the fault recordersshould be automatically transmitted. Real-timesynchronization is necessary so that the data re-corded at the various points can be allocatedclearly to each fault event. CFE decided to installsynchronization using GPS (global positioningsystem) receivers. High-precision real-time syn-chronization allows users to compare the logs ofthe connected fault recorders with those of theprotection relays from different locations.

Fig. 4 System concept


Power Quality


� The special advantagesAlways flexibleThe SIMEAS R is a multifunctional recorder withthe following basic functionalities:

� Fault recorder

� Power/frequency recorder

� Round-the-clock (digital or mean value)recorder

� Message printer

� Voltage dip recorder

Of these five functionalities, CFE primarily uses thefault recorder.

Optional add-on packageIn addition, CFE acquired the optional add-onpackage for OSCOP P. This software module(DIAGNOSE) enables automatic calculation andreporting of the fault location on a line.

�ConclusionThe comprehensiveness of the SIMEAS R andOSCOP P fault recording system provides CFEwith a uniform system with no limits to furtherextensions. The profound know-how and ex-pertise of the local Siemens project managerswas decisive in achieving the high degree ofcustomer satisfaction.

Fig. 5 Example of a system configuration for the substations in Rio Bravo and Anáhuac



Power Quality



Business Processes

The energy business with electronic processes(e-procure)

� The companyE.ON is the world's largest private energy servicescompany with sales of over EUR 46 billion andabout 66,000 employees. The company is clearlyfocused on its core businesses of electric powerand gas. E.ON Energie is one of Europe's largestenergy services companies and is active in nineEuropean countries. Its 16 million customers relyon E.ON Energie for their daily supply of electric-ity and gas in the Netherlands, Hungary, CzechRepublic, Switzerland, Italy, Poland and othercountries.

� The starting situationDeregulation and related unbundling activities inthe energy industry have led to changes in pur-chasing processes (smaller units, network break-ups, etc.) As a result, there is a growing demandfor increased availability of electric power systems(along with reductions in personnel and invento-ries), which means that replacement parts must bemade available faster.

� The conceptThese developments inevitably require the optimi-zation of procurement processes in the energy in-dustry. The rapid development of Internettechnology in combination with economical net-working - even of widely different IT systems aswell as corporate ERP standards (Enterprise Re-source Planning) - now make this possible. Cus-tomary procurement channels for goods andservices can therefore be drastically shortened andorder handling costs can be reduced.

Such integrated B2B solutions are designedmainly to optimize order handling both for thecustomer and the supplier. The entire purchasingprocess, from planning to procurement and fromorder approval to invoicing, is performed auto-matically on the Internet or Intranet.

A decision regarding the use of Internet-basedprocurement solutions depends principally on theordering process costs, the ordering frequency andthe number of suppliers involved. E.ON had al-ready integrated the electronic procurement pro-cess for so-called "C items" (not directly requiredfor production) into the SAP system and used itsuccessfully in electronic ordering. This resulted

Workflow Efficiency fromStart to Finish

in a significant decrease in the high administrativeand purchasing costs, which often exceed the ac-tual value of such items.

Of course this approach doesn't need to be limitedto typical "C items. " So it made sense to apply thissolution to other areas as well, to make orderingeasier for the "end user" in purchasing and in theservices area.

One requirement for expanding the use of this so-lution is the generation and integration of elec-tronic product catalogs. The challenge in elec-tronic integration is in the details.

Because the energy industry in particular tends toneed complex products that are tailored to partic-ular requirements and specified or configured forvarious applications by an engineer. In the past,needed products were selected from a catalog bythe engineering department and recorded in spe-cial Excel lists. Only then was a request conveyedto the appropriate purchasing function.

Fig. 1 Procurement process chain

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The creation of a configurable electronic productcatalog by Siemens PTD PA enabled E.ON to ex-pand the already successfully implemented elec-tronic solution for "C items" to these morecomplex products. E.ON's objective in integratingthe catalog into its SAP system was to electroni-cally integrate all steps in the purchasing processinto this SAP System and to eliminate any mediadiscontinuities (product catalog, notepads, Excellists etc.) as well as manual interactions.

� The special advantagesE-collaboration: The ordering party (buy side)and supplier (sell side) always collaborate elec-tronically.

E.ON has succeeded, in conjunction with SiemensPTD, to establish an e-collaboration system be-tween the two partners. To achieve this, two teamswere created (buy and sell side) that worked to-gether closely to define and implement this cus-tomer's requirements. The link between the twosystems was then established swiftly, and the im-plementation of the solution was completed witha four-week trial run in January 2004.

The integration of the product catalog by SiemensPTD has reduced the workload for participants onboth sides and substantially shortened the turn-around times of orders. All processes related toprocurement are now handled electronically.E.ON employees can configure and buy productsthey need directly from their desk now - withoutleaving the internal SAP system!

What's more, E.ON engineers can electronicallyaccess any information for the entire Power Auto-mation product line. They can for instance selectand order combinations of customer-specificproducts online. The required approval andrelease functions are integrated into the systemand performed online in order to assure the nec-essary transparency of the ordering processes.Time-consuming request procedures in other sys-tems or application changes are no longer needed.An encrypted link ensures maximum data secu-rity.

Unique in this solution is the exchange of currentinformation directly over a cost-effective Internetlink between the master product data stored atPTD PA and the installed SAP Enterprise BuyerSystem. As the Buyer in this system, E.ON has ac-cess to the very latest PA product information,configuration schemes, drawings, technical de-scriptions, customer-specific prices and agreed-upon commercial conditions via its purchasingsystem. Consequently, the Buyer has around-the-clock access to all relevant information.

Due to the electronic interface between the SAPsystem at E.ON and the certified SAP interface inthe Siemens system, the order entry at this end isalso performed in electronic form directly in theSAP system and can be processed immediately:Another advantage, which not only helps cut costsbut also minimizes keying errors during order en-try, speeding up the ordering process.

The entire ordering process chain now runs elec-tronically and interface-free. As a result, productselection is simplified and the process takes muchless time.

Fig. 3Integrated ordering processdescription, B2B solution

Fig. 2SAP purchasing portal

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Business Processes

�Credit process replaces invoicingTo further simplify the process, E.ON uses a creditmethod in payments for B2B orders. A definedbudget is agreed upon with the supplier as aframework for orders to be placed by the cus-tomer side. What sets this approach apart is thatSiemens, rather than the customer, monitors thebudget limit and informs E.ON when the agreed-upon budget is reached. So it is the supplier whokeeps track of the budget. Siemens benefits by thetransparency of the order volume that can be ex-pected over a given period of time.

�ConclusionA key argument for the integration of the PTDproduct catalog was the opportunity to notmerely integrate static product data but to alsointeractively configure the desired products spe-cifically for the intended application. The re-sulting product selection with the agreed-uponpricing is immediately displayed to the buyer inthe SAP System and directly processed online.As a result, the project manager obtains a pre-cise view of the required budget early, i.e. at thetime of the product selection. A key advantage,since tracking the budget is important, in addi-tion to tracking the availability of electricalequipment.

With this system, E.ON can now order online,through its own SAP system, any SIPROTECrelays it needs - always with the very latest dataat hand. The company predicts significant costsavings due to the simplified ordering process.During the introductory phase, E.ON stillpegged the internal order release limit in its SAPsystem at an order value of EURO 10,000.00.This limit is individually adjustable and willsoon be increased. The objective is to process allE.ON orders to Siemens Power AutomationDivision by this electronic method.

Since this approach is so new here, potentialsavings can only be put in perspective by refer-ring to other B2B processes: Typical savings inthe required transactions are in the range of15 % to 20 %.

The advantages on both the customer side andthe supplier side relate to the simplified order-ing process.

Specifically as a result of:

� Measurable process improvements

� Always up-to-date product data

� Supplier-side data maintenance

� No waiting for product information, selectionor pricing

� Visibility of the complete product line

With this approach, E.ON receives all the re-quired information to configure currentlyneeded products within its own purchasing Sys-tem - without leaving this System or having tochange to other applications - and to place theentire order directly online in its SAP System inaccordance with agreed-upon conditions.

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Fig. 5 SAP purchasing portal, shopping basket function

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Fig. 4 PTD PA product information


92

Europe

AustriaSiemens AG ÖsterreichSiemensstr. 90 - 921211 WienPhone: +43-5-1707-23252Fax: +43-5-1707-53075

BelgiumSiemens N. V.Demeurslaan 132B-1654 HuizigenPhone: +32-2-536-7789Fax: +32-2-536-6900

Czech RepublicSiemens s. r. o.Evropska 33aCZ-160 00 PrahaPhone: +420-2-3303 2132Fax: +420-2-3303 2190

DenmarkSiemens A / SBorupvang 3DK-2750 BallerupPhone: +45-4477 4820Fax: +45-4477 4034

FinlandSiemens OsakeyhtiöMajurinkatu 6FIN-02600 EspooPhone: +358-10-511 3094Fax: +358-10-511 3770

FranceSiemens S. A.. S.9, rue du Docteur FinotF 93527 Saint Denis, Cedex 2Phone: +33-1-4922 3972Fax: +33-1-4922 3090

GreeceSiemens A. E.Artemidos 8GR-151 10 Amaroussio/AthenPhone: +30-210-6864 717Fax: +30-210-6864 536

Siemens A.E. NorthGeorgikis Scholis 89GR-54110 ThessalonikiPhone: +30-2310-479 217Fax: +30-2310-479 265

ItalySiemens S.p. A.Via Vipiteno 4I-20 128 MilanoPhone: +39-02-6676 2391Fax: +39-02-6676 2213

IrelandSiemens Ltd.Leeson CloseDublin 2Phone: +353-1-216 2425Fax: +353-1-216 2458

NetherlandsSiemens Nederland N.V.Prinses Beatrixlaan 262595 AL Den HaagPhone: +31-70-333 3126Fax: +31-70-333 3225

Norway

Siemens A / SOstre Aker vei 90N-0518 OsloPhone: +47-22-633 375Fax: +47-22-633 796

PolandSiemens Sp.z.o.o. Northul. Zupnicza 11PL-03-821 WarszawaPhone: +48-22-870 9127Fax: +48-22-870 8627

Siemens Sp.z.o.o. Southul. Gawronow 22PL-40-533 KatowicePhone: +48-32-2084153Fax: +48-32-2084259

PortugalSiemens S. A..Rua Irmaos Siemens, 1- AlfagideP-2720 093 AmadoraPhone: +351-21-417 8361Fax: +351-21-417 8071

SloveniaBranch office: Siemens Austria

SpainSiemens S.A.Ronda de Europa 5E 28 760 Tres Cantos (Madrid)Phone: +34-91-514 7561Fax: +34-91-514 4730

SwitzerlandSiemens-Schweiz AGFreilagerstr. 28CH-8047 ZürichPhone: +41-1-585-586645Fax: +41-1-585-544755

TurkeySiemens Sanayi ve Ticaret ASYakacik Yolu No: 111, Kartal34870 Istanbul-TurkeyPhone: +90-216-459 2721Fax: +90-216-459 2682

HungarySiemens Rt.Gizella út 51-57H-1143 BudapestPhone: +36-1-471 1686Fax: +36-1-471 1622

United KingdomSiemens plcSir William Siemens HousePrincess RoadManchester M20 2URPhone: +44-161-446 5119Fax: +44-161-446 6476

Africa

EgyptSiemens Ltd.Cairo, P.O.Box 775 / 1151155 El Nakhil andEl-Aenab St.El-Mohandessin, GizaPhone: +20-2-333 3644,Fax: +20-2-333 3608

MoroccoSiemens S. A.Km 1, Route de RabatAin-Sebâa20250 CasablancaPhone: +212-22-351 025Fax: +212-22-340 151

NigeriaSiemens Ltd.,98/100, Oshodi /Apapa ExpresswayLagosPhone: +234-1-4500 137Fax: +234-9-523 6133

South AfricaSiemens Ltd.,300 Janadel AvenuePrivate Bag X71Halfway House 1685Phone: +27-11-652 2287Fax: +27-11-652 2497

Australia

Siemens Ltd., PT & DMelbourn Head Office885 Mountain HighwayBayswater VIC 3153Phone: +61-3-9721 2819Fax: +61-3-9721 7328

North America

USASiemens PT&D, Inc.7000 Siemens Rd.Wendell , NC 27591-8309Phone: +1 800 347 6657

+1-919-365 2196Fax: +1-919-365 2552Internet: www.siemenstd.com

Central America

Costa RicaSiemens S.A.,P.O.Box 10022-1000La Uruca200 Este de la PlazaSan JoséPhone: +506-287 5120Fax: +506-233 5244

MexicoSiemens S.A. DE C.V.Poniente 116 No. 590Col. Ind. VallejoDelegación Azcapotzalco02300 Mexico D.F.Phone: +52-5-328 5336Fax: +52-5-328 5324

South America

ArgentinaSiemens S.A.Julio A. Roca 516Capital FederalC1067ABN Buenos AiresPhone: +54-11-4738 7194Fax: +54-11-4738 7319

BrazilSiemens Ltda.Av. Mutinga, 380005110-901 São Paulo -SPPhone: +55-11-39083 911Fax: +55-11-39083 988

ColumbiaSiemens S.A., GDHSantafe de Bogota,D.C.Carrera 65 No. 11-83Apartado 8 01 50ConmutaSantafé de Bogotá 6Phone: +57-1-294 2272Fax: +57-1-294 2500

VenezuelaSiemens S.A.,Avenida Don Diego Cisneros/Urbanización Los RuicesCaracas 1071Phone: +58-212-203 8755Fax: +58-212-203 8613

Asia

ChinaSiemens Ltd., PT & DNo. 7, Wangjing ZhonghuanNanlu, Chaoyang DistrictBeijing, 100015Phone: +86-10-6472 1888

ext. 3149Fax: +86-10-6472 1464

Hong KongSiemens Ltd., PTD58/F Central Plaza18 Harbour RoadWanchai, Hong KongPhone: +852-25 83 3362Fax: + 852-28 02 9908

IndiaSiemens Ltd., PTD6A Maruti Industrial AreaSector-18Haryana 122 015 / GurgaonPhone: +91-124-634 9359

ext. 2100Fax: +91-124-634 6431

IndonesiaP.T. Siemens IndonesiaJl. Jend. A. Yani Kav. B 67-68Pulo MasJakarta 13210Phone: +62-21-472 9153Fax: +62-21-472 15055,

472 9 201

KoreaSiemens Ltd6th Floor Asia Tower Bldg726, Yeoksam-dong,Kangnam-guSeoul 135-719, KoreaPhone: +82-2-52 77 805Fax: +82 2 52 77 889

MalaysiaSiemensElectrical Engineering Sdn Bhd13th Floor, CP Tower11 Section 16/11, JalanDamansara46350 Petaling JayaSelangor Darul EhsanPhone: +60-3-7952 5324

(direct)Phone: +60-3-7952 5555

(switchb.)Fax: +60-3-7957 0380

PakistanSiemens Pakistan EngineeringCo.Ltd PT&DB-72, Estate Avenue,S.I.T.E.LKarachi 75700, PakistanPhone: +92-21-2566 213Fax: +92-21-2566 215

PhilippinesSiemens Inc., PT & D14 F Centerpoint Bldg.Julia Vargas AvenueOrtigas, Pasig City 1605Phone.: +63-2-637 0900Fax.: +63-2-633 5592

SingaporePower Automation28 Ayer Rajah Crecent05-02/03Singapore 139959Phone.: +65-6872 2688Fax: +65-6872 3692

TaiwanSiemens Ltd., PT & D Dept.13, Yuan Qu StreetNan Gang District, 8F-1115 Taipei, Taiwan R.O.C.Phone.: +886-2-2376 1829Fax: +886-2-2378 6430

ThailandSiemens Limited, PTDCharn Issara Tower II, 25ndFloor2922/283 New Petchburi RoadBangkapi, Huay KwangBangkok 10310Phone.: +66-2-715-4771Fax: +66-2-715-4701

VietnamSiemens AGRepresentationThe Landmark Building, 2ndFloor5B Ton Duc Thang Str.District 1Ho Chi Minh CityPhone.: +84-8-825 1900Fax: +84-8-825 1580

Middle East

IranSiemens Sherkate Sahami(Khass) (SSSK)Siemens HouseAvenue Ayatollah Taleghani 32Teheran 15Phone: +98-21-614 1Fax: +98-21-614 2294

KuwaitNational & German Electrical &Electronic Services CompanyGulf Investment Corporation(GIC) BuildingAl-Mubarak St., Block – 41st & 2nd Floor32041 SharqPhone: +965-241-8888Fax: +965-246 3222

United Arab EmiratesSiemens Resident EngineersAl Moosa Tower, 21st FloorSheikh Zayed RoadDubaiPhone: +971-4-331 9578Fax: +971-4-331 9547

Siemens Resident EngineersHamdan StreetP.O. Box 732Abu DhabiPhone: +971 2 626 2800Fax: +971 2 626 9871

Saudi ArabiaSiemens Ltd PT&DJeddah Head OfficeP.O. Box 462121412 JeddahPhone: +966-2-665 8420Fax: +966-2-665 8490

+966-2-663 0894

Siemens Companies and Representatives of the Power Transmission and Distribution Group

Printed in GermanyKGK 0505 4.0 92 En 101393 6101 D6336


www.siemens.com/ptd Order No.: E50001-K4452-A101-A1-7600

Published by

Siemens Aktiengesellschaft

Power Transmission and DistributionEnergy Automation DivisionPostfach 48 06

90026 NuernbergGermany


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