HIS – Highly Integrated Switchgearup to 145 kV

Power Transmission and Distribution

Type 8DN872.5 kV–145 kV

HIS – Highly Integrated Switchgear –solves space problems

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You needn’t have any space worrieswith HIS, the gas-insulated switchgearfor indoor and outdoor use, becauseHIS requires less than half the spaceof a comparable air-insulated switch-gear.

The 8DN8 type HIS is a compactswitchgear solution for a rated voltageof up to 145 kV, used mainly for re-newal or expansion of air-insulatedoutdoor and indoor substations, par-ticularly if the operator wants to carryout modifications while the switch-gear is in service. With new construc-tion projects, high site prices andincreasingly complex approval pro-cedures mean that space requirementis the prime factor in costing. Withthe HIS solution, the circuit-breakers,disconnectors, earthing switches andtransformers are accommodated incompressed gas-tight enclosures, thusrendering the switchgear extremelycompact.

Thus, you can also meet the growingdemands on your switchgear withinthe scope of the existing site.

5 CB H-arrangement

HIS – Highly Integrated Switchgear –is the cost-effective alternative

Cost-effective and versatile

With HIS, it is possible to imple-ment all commonly-usedsubstation configurations byusing compact, standardizedmodules.

Thus for example, one air-insulated (conventional) baycan be replaced by two HIS bays– with space to spare! Low oper--ating costs, minimal mainte-nance requirement and longservice life of the system addi-tionally help to reduce life-cyclecosts. Conversion is readily pos-sible using factory preassem-bled and tested units. In addi-tion, HIS fits easily into yourexisting control and protectionconcept – whether it is conven-tional, digital or process-busbased with SICAM® HV.

In this way, HIS can be inte-grated cost-effectively andflexibly in your substation.

Low investment cost

Computer-aided EngineeringTools and compact supply unitsenable short planning and deli-very times. By virtue of thesmall, compact bay structure,only a few foundations are ne-cessary. Civil works are reducedto a minimum, so that even inmountainous, rocky terrain,construction presents no prob-lems. The switchgear is de-livered to the site in already pre-assembled and tested units.This significantly reduces thetime required between issuingthe contract and handover ofthe complete switchgear to theclient. In addition, HIS requiresonly half the ground area of air-insulated switchgear. Extensionof existing outdoor switchgearis, to a large extent, possibleduring operation. For this pur-pose, it is only necessary to

isolate subsections of the equip-ment for a short time. Thisminimizes switchgear outagetime.

In this way, you keep invest-ment cost down and ensureearly commissioning.

Safe, reliable operation

The operating personnel areprotected from contact with liveparts by virtue of the enclosedconstruction. Integrated discon-nectors and earthing switcheson the busbar and outgoingfeeder side permit risk-free iso-lation and earthing of switch-gear sections. Outgoing feederearthing switches can also besupplied in the make-proofhigh-speed version. Releaseof conductor connections toestablish isolating sections andthe use of mobile earth rodscan be avoided. Rupture dia-phragms with defined direc-tions of discharge prevent un-acceptably high pressure risein the enclosures. Bay construc-tion on one level assistsstraightforward layout of theswitchgear. In addition tooperator safety, the HIS solutionprovides excellent protectionagainst vandalism. If a faultshould occur – it can be quicklyremedied. Replacement of com-plete bays is possible at shortnotice, so that downtime of theswitchgear is reduced to a mi-nimum. Replacement parts areavailable from current produc-tion within 24 hours.

Thus, you ensure maximumsafety for your personnel andyour switchgear – and reliableoperation.

Environmentallycompatible

The environment also benefitsfrom your HIS. The oil-freeoperating mechanism andthe extremely effective sealingof the enclosure prevent anyenvironmental contamination.Their long service life and mini-mal space requirement additio-nally conserve resources.

This means that you are pro-tecting the environment for thefuture.

Impervious to damageand maintenance-free

Once the switchgear is opera-tional, it will operate reliablyand require minimal main-tenance for at least 50 years.Only after 10 years do we re-commend an initial visual in-spection. Being completely en-closed, the cleaning required isalso minimal. The high qualityof the switchgear is a result ofcomprehensive quality manage-ment. The enclosures are cor-rosion-resistant aluminum cast-ings and the motor-operatedmechanisms are selflubricating.The switchgear possesses noexposed contact systems andoperating linkages, so that theyare protected from external in-fluences, even under corrosiveenvironmental conditions. It isalso aseismic and imperviousto wind.

This means that you can relyon your switchgear at all times– with extremely low operatingcost.

The creative solution

HIS offers a creative solution toyour switching functions, basedon GIS technology by being:

• compact• low-cost and• modular for indoor as well as

outdoor application.

Installation of our switchgearpresents no problems, even inrocky, mountainous regions

You can rely on our switchgeareven in the most aggressiveenvironment

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Compactby virtue of innovative technology

HIS switchgear is three-phase encapsulated in order to achieve anextremely compact module size. The switchgear is clearly laid outon one level. Aluminum is used as enclosure material. As a result,the switchgear is free from corrosion and exceptionally lightweight.State-of-the-art design methods and casting techniques permitoptimum dielectric and mechanical construction of the enclosures.

Sulfur hexafluoride (SF6) is used as the insulating and arc-quenchinggas.

All modules are attached to one another by flanges. The gas-tightness of the flange joints is ensured by the Siemens O-ringsealing principle, proven over years of service. Gas-tight bushingspermit subdivision of the bay into several distinct gas compart-ments. Each gas compartment is fitted with its own gas monitor,rupture diaphragm and filter material. Static filters absorb moistureand decomposition products. In the improbable event of a fault,bursting plates prevent unacceptably high pressure buildup in theenclosures. When they activate, diverter nozzles ensure defineddirection of discharge of the gas. The outdoor-proof enclosuresand operating mechanisms are fitted with space heaters. Screwsand nuts are corrosion-proof.

1 Circuit-breaker 2 Spring-stored-energy

operating mechanismwith circuit-breakercontrol unit

3 Outgoing feeder mod-ule with disconnectorand earthing switch

4 Splitting module 5 Current transformer 6 Voltage transformer 7 Transformer terminal

box 8 High-speed earthing

switch 9 Cable sealing end10 SF6/air bushing11 Supporting structure

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In/out feeder

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The center-piece of the HIS switchgear is the three-phase encap-sulated circuit-breaker module with its two elements:

• Interrupter unit• Operating system.

The interrupter unit and the actuating mechanism are based onproven, identical designs already widely used in outdoor and gas-insulated switchgear systems.

Interrupter unit

The interrupter unit used for arc quenching in the circuit-breakeroperates on the self-compression principle. By virtue of the lowoperating energy required, very low mechanical forces occur. Thisresults in a favorable effect on the mechanical loading of thecircuit-breaker itself, on the enclosure and on the foundationdesign.

The current path

In the case of a self-compression circuit-breaker, the current pathis formed by the contact support (1), the base (6) and the movingcontact cylinder (5). In the closed condition, the operating currentflows through the main contact (3). An arcing contact (4) isconnected parallel to the main contact.

Interruptionof operating current

During the breaking operation, the main contact (3) opens firstand the current commutates on the arcing contact (4) which isstill closed. By this means, erosion of the main contact is avoided.As the breaking operation progresses, an arc develops betweenthe contacts (4). The contact cylinder (5) moves simultaneouslyin the base (6) and compresses the remaining arc-quenching gas.The compressed arc-quenching gas flows through the contactcylinder (5) into the contact gap and extinguishes the arc.

Interruption of fault current

If the short-circuit current is high, the arc quenching gas at thearcing contact is heated up considerably by the energy of the arc.This leads to a pressure rise in the contact cylinder. Consequently,the energy required for production of the arc quenching pressuredoes not have to be supplied by the operating mechanism. As theswitching operation progresses, the fixed arcing contact releasesthe outflow from the nozzle (2). The gas now flows out of thecontact cylinder and through the nozzle, thus extinguishing thearc.

Circuit-breakermodule

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1 Contact carrier2 Nozzle3 Main contact4 Arcing contact5 Contact cylinder6 Base

Circuit-breaker module

Operating mechanism

The stored-energy spring me-chanism provides the force ne-cessary to open and close thecircuit-breaker. It possesses acompact, corrosion-resistantaluminum enclosure. The clos-ing spring, as well as the open-ing spring, are visibly arrangedin the operating block. The en-tire operating unit is completelyseparated from the SF6 gascompartments. The use of anti-friction bearings and a main-tenance-free charging mecha-nism assure reliable operationfor decades. In addition, provendesign principles from Siemenscircuit-breaker technology, suchas vibration-isolated latches andload-free isolation of the charg-ing mechanism, have beenemployed.

The operating mechanism pro-vides the following advantages:

• Defined contact positionis maintained, even onfailure of auxiliary energy

• Breaking is possible ir-respective of the state of the closing spring

• Large number of mechanicalswitching operations

• Minimum quantity ofmoving parts

• Compact construction. 9

1 Closing release2 Cam plate3 Coupling linkage4 Operating rod5 Closing connecting-rod spring6 Opening connecting-rod spring7 Closing spring8 Hand-wound mechanism9 Charging mechanism

10 Charging shaft11 Roller lever12 Closing damper13 Operating shaft14 Opening damper15 Opening release16 Mechanism housing17 Opening spring

Breaker in “On” position Breaking:Main contact opened

Breaking:Arcing contact opened

Breaker in“Off” position

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Diagrammatic viewof three-position unit

Earthing switch closed

Disconnector closed

Neutral position

The functions of disconnectingand earthing switches are com-bined in a three-position unit.

The moving contact either closesthe isolating gap or connects thehigh-voltage conductor to thefixed contact of the earthingswitch. This design ensures natu-ral mechanical interlocking of thetwo functions in relation to oneanother, which subsequently nolonger need be taken into ac-count in the electrical interlock-ing of the bay. The fixed contactof the earthing switch is broughtout of the enclosure for test pur-poses. In a third neutral position,neither the disconnector nor theearthing switch contact is closed.The three poles of a bay are me-chanically interconnected; thusall three poles are operated joint-ly with a single motor-operatedmechanism. Power transmissioninside the enclosure is effectedby means of compressed gas-tight, rotary insulating shafts.Alarm switches and contact po-sition indicators are mechanicallyreliable and are attached directlyto the operating shaft. Manualemergency operation is possible.

The high-speed earthing switchis a moving-contact earthingswitch. The moving contacts atearth potential slide in the caseof this switch into the tulip-shaped fixed contacts. The earth-ing switch is fitted with astored-energy spring mecha-nism which is charged bymeans of an electric motor.

Current and voltage transfor-mers are employed for the pur-pose of measurement and pro-tection. They are supplied innumerous variants – from con-ventional transformers, rightup to state-of-the-art currentand voltage sensors.

Current transformermodule

Generally, optimized-per-formance inductive currenttransformers are used. The cur-rent transformer can be integrat-ed anywhere in the bay andsubstation construction. Thehigh-voltage conductor formsthe primary winding. The coreswith secondary windings aredesigned in accordance withaccuracy class rating and per-formance requirements. Tap-changing to the different trans-formation ratios is made possi-ble by secondary connectionsof current transformers. Thelatter are brought out of theenclosure via a gas-tight bush-ing plate and are electricallyaccessible in the transformerterminal box underneath thecircuit-breaker.

Voltage transformermodule

Both inductive and optimized-performance voltage trans-formers are employed. Voltagetransformers can be arrangedon either side of the outgoingfeeder disconnector. The second-ary connections are broughtout of the enclosure via a gas-tight bushing plate and areelectrically accessible in thetransformer terminal box un-derneath the circuit-breaker.

High-speedearthing switch

Instrumenttransformers

Disconnecting andearthing switches

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Diagrammatic viewof three-position unit

Earthing switch closed

Disconnector closed

Neutral position

Optimized-perfor-mance currenttransformer module

Example of optimized-performance voltagetransformer module

High-speedearthing switch

Termination modules

Termination modules link theHIS bays to the equipment bymeans of the following:

• Overhead line• Transformer or reactor• Cable.

Thus, they form the transitionfrom the SF6 gas insulation in-side the enclosure to other in-sulating media.

Cable termination module

This three-phase encapsulatedmodule links the metal-enclosed HIS switchgear to ahigh-voltage cable. In the cabletermination module, it is readilypossible to connect all commontypes of high-voltage cables.

It is possible to employ bothconventional and plug-in cablesealing ends.

Extension module

The links necessary within abay are established by meansof extension modules.

SF6/air termination/surge arrester

The transition from the HISswitchgear to air-insulatedswitchgear modules or over-head lines is accomplished bythe single-phase SF6/air bush-ing termination. It can takethe form of a composite or por-celain insulator. This connectionis a combination of single-phase connecting modules andSF6/air bushings. Overall length,shield shape and creepage pathwill be designed according toinsulation coordination, mini-mum clearance and degree ofpollution.The SF6/air termination issuitable for air-insulated con-nections of HIS to:

• Overhead lines• Transformer or reactor

bushings• High-voltage cables

sealing ends.

The innovative design of HISgives the possibility to integratea surge arrester into the over-head line bushing, which re-sults in additional space saving.

Splitting of the connectionsof the three phases to achievethe necessary clearance inair for conductor insulationbetween one another is 45°.

Transformertermination module

The single-phase transformertermination module is connect-ed, like the SF6/air termination,by means of a combination oflink modules to the three-phaseencapsulatedbasic bay. It provides the facilityof transition from the gas insu-lation directly to the bushing ofoil-insulated transformers orreactors. For this purpose, thetransformer bushing must bedesigned so as to be oil- andpressure-tight. Movementcaused by temperature and dif-fering subsidence of the foun-dations of switchgear and trans-former are corrected byexpansion joints.

Terminationmodules

Extensionmodule

Extension module

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SF6/air termination withintegrated surge arrester

Transformertermination module

Example of cabletermination module(plug-in type)

Proven and innovative switchgear control

All the elements required for control and monitoring are accommodatedin a decentralized arrangement in the high-voltage switching devices.The switching device control systems are factory-tested and the switchgearis usually supplied with bay-internal cabling all the way to the neutral bayinterface. This minimizes the time required for commissioning and reducesthe scope for possible faults.

As standard, the control and monitoring system is made up of electro-mechanical components.Alternatively, the digital intelligent control and protection systemSICAM HV with comprehensive diagnostics and monitoring functions isavailable. More detailed information on the substation state means thatmaintenance intervals can be geared to the condition of the switchgear.Lift-cycle costs can consequently be reduced even further.

Gas monitoring

Gas-tight insulating partitions divide each bay into functionally distinctgas compartments (circuit-breaker, disconnector, voltage transformer,etc.). The gas compartments are under constant observation by meansof density monitors with integrated indicator; any nonconformity isimmediately signaled. The optionally available monitoring system withSICAM HV includes sensors that allow a trend forecast for each gascompartment.

Operating mechanismcubicle of the circuit-breaker

Flexible and reliable protection in bay and substation control

Control and feeder protection are accommodated in a separatelyinstalled control cubicle.

If requested, we can of course supply the HIS switchgearfeaturing any customary bay and substation control equip-ment. We provide uniform systems to meet your individualrequirements. Neutral interfaces in the switchgear controlallow link-up of

• a conventional control system with contactor interlockingand control panel

• digital control and protection comprising user-friendly baycontrollers and substation automation with PC operatorstations (HMI)

• an intelligent, uniformly networked digital control andprotection system with supplementary monitoring andtelediagnostics functions.

From the wide range of Siemens control and protectionequipment, we can provide you with a customized concept;everything comes from a single source (see special printedpublication).

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Control and MonitoringUniform and flexible control and protection system

In order to permit optimumshipping and installation onsite, our switchgear units aretransported in the largestmanageable shipping units. Theheights of the modules are tai-lored to comply with standard-ized container dimensions, inorder to ensure cost-effectivetransportation throughout theworld.

In shipping modules which con-tain switching elements, alloperating attachments are fac-tory-set on dispatch. Necessaryshipping splits are corrosion-protected and sealed withtransport covers.

Packing of the material to beshipped is selected accordingto the type of shipment, dura-tion and means of transport,and nature and duration ofstorage. If necessary, sealedpacking is provided which willbe suitable for ocean shipmentand a transport and storage du-ration of up to 12 months. Inspecial cases, sealed packingcan also be designed for a lon-ger period.

Transport, installation,commissioning & maintenance

Delivery of factory pre-assem-bled units significantly reduceslabor cost and time taken forinstallation on site. The ship-ping modules are transportedwith the aid of simple equip-ment to the installation site andaligned for assembly.

By virtue of the compact baydimensions, minimal foun-dations are necessary. Excava-tion is reduced to a minimum.The modules can easily be ma-neuvered and quickly adjusted.Only minimal anchoring andadditional steel supports arenecessary.

On the secondary side, theonly work to be done is cablingbetween the bays.

Simple operations, detailed in-stallation instructions and theuse of only a few special toolspermit quick, simple installationof the switchgear, even bycustomer personnel under thesupervision of an experiencedSiemens engineer. If required,you can avail yourself of ourrange of training facilities.

After completion of installation,all switchgear and electrical cir-cuits for control and monitoringare checked for proper mecha-nical and electrical function.Flanged joints assembled onsite are examined for gastight-ness. All other flanged jointshave already been tested at ourfactory.

The tests are carried out inaccordance with IEC 517. Finaltest reports document theresults.

Our HIS switchgear units havebeen designed and manufac-tured to ensure optimum balancebetween design, materials usedand maintenance work neces-sary. Time needed for cleaninghas been reduced to a mini-mum, because the switchgearis thoroughly enclosed. The castaluminum enclosures are cor-rosion resistant and the motor-operated mechanisms areself lubricating. Under normaloperating conditions, our HISswitchgear units can be con-sidered maintenance-free. Werecommend an initial visualinspection only after 10 years,with the first overhaul after25 years.

TransportErectionand installation

Commissioning Maintenance

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Renovation of air-insulated indoor switchgear Loading onto truck

QualityAssurance

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The quality of Siemens gas-insulated switchgear is assured bycontinuous, progressive Quality Management. This has beencertified since 1983 in accordance with CSA Z299 and since 1989in accordance with DIN EN 9001.

For us, Quality Assurance means that our processes are primarilycustomer-oriented.

The Quality Assurance system includes all operations of the productlife-cycles, from marketing to development and service. RegularManagement Reviews and internal and external audits for allprocesses ensure that this system is constantly effective and up-to-date. The basis is formed by continuous documentation of alloperations relating to quality. This means that our switchgearmeets even the very highest standards of quality.

Consistent Quality Management naturally also extends to theproduction of our switchgear. Assembly in clean rooms, combinedwith comprehensive process inspection and routine tests oncomponents, sub-assemblies and modules, ensure reliable switch-gear operation. The mechanical routine tests are followed, as finalquality verification prior to shipment, by the high-voltage routinetest on the complete bay, or on the complete shipping modules.

Technical Data

Switchgear Type HIS Type 8DN8

Rated voltage up to 145 kV

Rated frequency 50/60 Hz

Rated power-frequencywithstand voltage (1 min.) up to 275 kV

Rated lightning impulsewithstand voltage (1.2/50 µs) up to 650 kV

Rated current up to 3150 A

Rated breaking current up to 40 kA

Rated impulse current up to 108 kA

Rated short-time current up to 40 kA

Leakage rate/year � 0.5 %

Standards EN/IEC

Temperature –30 °C to +55 °C

Factory testing

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Examples ofswitchgear configurations

H-arrangement

Previously: Air-insulatedswitchgear unit; Spacerequirement: approx. 1600 m2

Subsequently: HIS – HighlyIntegrated Switchgear; Spacerequirement: approx. 650 m2

35 m

45 m

27 m

24 m

8 m

Extension, air-insulated outdoor switchgear, in-line arrangement

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Busbar A

-Z1

Busbar B

-Z2

-Z4

-QZ1 -QZ2 -T1-Z3 -T5

-Q0

Subsequently:HIS – Highly IntegratedSwitchgear

Busbar A Busbar B

-QZ1 -QZ2

-Z1

-Q0-T1 -T5

Previously:Air-insulated indoorswitchgear

Renovation of air-insulated indoor switchgear, double busbar arrangement

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2 m

2 m

7 m

16 m

-Z1 -Z1

-QZ1 -QZ1

-QZ1 -QZ1-QZ1 -Q0 -QZ2

-T1 -T1

-Q0 -Q0

-QZ9 -QZ9

-T5 -T5

-Q8 -Q8

-Z1 -Z1

M M

M M

M M

M M

M M

M MM

-T1 -T2

Single-line diagram

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m

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HIS switchgear, 3-circuit-breaker H-arrangement

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Siemens AGPower Transmissionand DistributionHigh Voltage DivisionPostfach 32 2091050 ErlangenGermany

www.siemens.com/ptd

Subject to change without prior notice

Order No. E50001-U113-A217-V3-7600Printed in GermanyDispo-Stelle 3000061D7138 TV/Wü PA05032.

For further information,please contact:

Please send me information on the following subjects:

HIS CD-ROM for Windows 95/NT 4.0 or higher

Further copies of this brochure

Product range: Gas-insulated switchgear

Gas-insulated switchgear up to 145 kV

Gas-insulated switchgear up to 245 kV

Gas-insulated switchgear up to 550 kV

Container-type switchgear

Digital control and monitoringfor high-voltage switchgear

Tel. +49 91 31/7-3 46 60Fax +49 91 31/7-3 46 62E-mail: his@ptd.siemens.de

www.siemens.com/his-switchgear

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