customer: cottonwood energy company, lp fac study optional.pdf · cottonwood energy company, lp...

Revision cJanuary 2002

TRANSMISSION AND SUBSTATION PROJECT’S

OPERATING COMPANY: EGSI-TX

CUSTOMER: COTTONWOOD ENERGY COMPANY, LPEJO # GS0021

FACILITY STUDYOPTIONAL SYSTEM UPGRADES

FOR1240 MW, IPP PROJECT NEAR HARTBURG, TX

WITH INTERCONNECTION ATHARTBURG 500KV SUBSTATION

CYPRESS 500KV SUBSTATION

PROJECT IDENTIFICATION NUMBER 140

REVISION: c

c 1/24/02 Issued to Entergy Management Team for Review PEI BO

b 1/09/02 Issued to Entergy Jurisdictional Team for Review PEI BO

a1 12/26/01 Issued to Entergy IPP Core Team for Review PEI BO

a 12/21/01 Issued to Entergy IPP Core Team for Review PEI BO

Rev IssueDate

Description of Revision DesignEngineer

ProjectManager

COTTONWOOD ENERGY COMPANY, LP FACILITY STUDY-OPTIONAL UPGRADES

Revision cJanuary 2002 i

Table of Contents

Section Page1. FACILITY STUDY SUMMARY..........................................................................12. SAFETY.................................................................................................................33. STUDY DETAILS FOR SYSTEM UPGRADES (OPTIONAL WORK)............3

A. SUBSTATIONS________________________________________________ 31. HARTBURG 500/230kv SUBSTATION _________________________ 3

a. ELECTRICAL WORK ............................................................................3b. SITE WORK............................................................................................7c. STRUCTURAL WORK...........................................................................8d. FOUNDATION WORK...........................................................................9e. RELAYING WORK ..............................................................................10

2. Cypress 500/230/138kv SUBSTATION__________________________ 13a. ELECTRICAL WORK ..........................................................................13b. SITE WORK..........................................................................................17c. STRUCTURAL WORK.........................................................................17d. FOUNDATION WORK.........................................................................19e. RELAYING WORK ..............................................................................21

B. TRANSMISSION LINES_______________________________________ 264. COST ESTIMATE SUMMARY.........................................................................265. SCHEDULE MILESTONES ..............................................................................266. OUTAGE REQUIREMENTS.............................................................................287. ATTACHMENTS................................................................................................31HARTBURG 500/230/13.8KV SUBSTATION...........................................................31CYPRESS 500/230/138KV SUBSTATION ................................................................31


Revision cJanuary 2002 1

1. FACILITY STUDY SUMMARY

MANDATORY

The mandatory work required was defined in a previous study dated March 2001.

OPTIONAL

This section identifies equipment that must be upgraded in order to allow increasedpower flow over Entergy equipment and facilities.

HARTBURG 500/230KV SUBTATION

This portion of the Facility Study identifies all of the components necessary to installa new 800MVA transformer bank and de-energize the existing 600MVA transformerbank. The transformer bank replacement is necessary in order to provide increasedpower flow capability from the Hartburg 500kV yard to the 230kV portion of theyard. In the event of a 500kV line failure between Hartburg and Cypress, anestimated 800MW of power will need to flow into the 230kV system through thetransformers at Hartburg.

The optional system upgrades at Hartburg, is estimated to be $16,730,464.00. Thisestimate includes overheads and tax gross ups, but not AFUDC. The estimateconsists of the following work:

• Installation of one new 500/230/13.8kV 800MVA autotransformer bank. Thebank will comprise four single-phase 160/222/267MVA autotransformersarranged to allow the fourth spare transformer to provide emergency backup inthe event of the failure of any one of the three other phase positions by changingthe physical connections of the transformers on the high, low and tertiary buses.

• These transformers will require an oil containment system because the substationsite sits next to a designated wetland area.

• Installation of one new 500kV gas circuit breaker with associated disconnectswitches in an empty position of the southeast ring bus.

• Installation of one new 230kV gas circuit breaker, with associated disconnectswitches in the new bay.

• Installation of a new 230kV South Bus to connect the new transformer bank to theexisting Helbig line. The establishment of a new bus and the connection of theHelbig line to the new bus will minimize the outage time required on the Helbigline to install, test and energize all new equipment associated with the installationof the new transformer bank.



• The existing 230kV breaker, switches and the existing North Bus will bedisconnected and removed.

• 500kV Breaker 13130 will be removed. The Bus No. 1 differential schemes andthe breaker failure schemes for several breakers will be modified accordingly.

• The existing 13.8kV reactors and Alternate Station Service transformer will beconnected to the tertiary of the new bank using rigid bus.

CYPRESS 500/230/138KV SUBSTATION:

The Cypress Substation will be expanded to a 3-position ring bus at 500kV, a 4-positionring bus at 230kV and to a full breaker-and-a-half scheme at 138kV. A 750MVA500/230kV autotransformer and a 300MVA 230/138kV autotransformer will be addedto the station. These two transformer banks along with the existing transformer bankswill increase the transfer capability of the station to 750MVA between the 500kV andthe 230kV yard, and 600MVA between the 230kV and the 138kV yard.

The optional system upgrades at Cypress, is estimated to be $29,836,668.00. Thisestimate includes overheads and tax gross ups, but not ADFUC. The estimateconsists of the following work:

• The installation of three 500kV breakers and associated switches and bus work tocreate a 3-position ring bus.

• The installation of three 1-phase 500/230/13.8kV, 150/200/250MVAtransformers.

.• The installation of four 230kV breakers and associated switches and bus work to

create a 4-position ring bus..

• The installation of one 3-phase 180/240/300MVA 230/138kV autotransformerbank with LTC.

• The installation of four 138kV breakers and their associated switches and buswork to create a breaker-and-a-half yard.

This study only examined electrical facilities within the Entergy System.Cottonwood Entergy Company LP is responsible for notifying neighboring utilities,for the coordination and accommodation of issues beyond the Entergy System.

No Environmental Assessment or Impact Study was undertaken for this FacilityStudy. If any significant environmental concern is identified during detailed design,this could impact both costs and project duration.



All relevant Entergy standards shall be followed in the implementation of the workoutlined in this document. In the case of conflicting information, Entergy Standardsand Specifications shall take precedence.

* Costs are calculated in 2002 dollars: These estimates are based upon calculationsthat incorporate current costs and availability for labor, materials, equipment, etc.Any changes in these economic parameters during design and/or construction ofthese facilities could impact this estimated cost.

All quantities listed below are approximate and could change during detail design.

2. SAFETY

Safety is a priority with Entergy. Safety will be designed into the substations andlines. The designs will be done with the utmost safety for personnel in mind for theconstruction, operation and maintenance of the equipment. Modifications requiredfor this interconnection will require personnel to work in energized substations.

3. STUDY DETAILS FOR SYSTEM UPGRADES (OPTIONAL WORK)

A. SUBSTATIONS

The work for the optional system upgrades of this study will be at theHartburg and Cypress Substations.

1. HARTBURG 500/230KV SUBSTATION

a. ELECTRICAL WORKReference drawings GJ0021EA1IPPP, GJ0021EA2IPPP, andGJ0021FS1IPPP, GJ0021FS2IPPP, G1167SO5IPPP andG1167SO6IPPP for the work detailed in this section

Entergy equipment required for the optional system upgrades willbe:

ELECTRICAL EQUIPMENT QUANTITY LEAD TIME*500kV1-phase, 500/230/13.8kV,160/222/267MVA AutotransformerNo. 2

4 ea 52wks

3-phase, 500kV, 3000A 63kA gascircuit breaker with two 3000-5A MRCT’s per bushing for relaying, andone 1500/3000-5A DR CT perbushing for metering

1 ea 48 wks



ELECTRICAL EQUIPMENT QUANTITY LEAD TIME*3-phase, 500kV, 3000A motoroperated vertical break disconnectswitch without grounding switch

2 ea 24 wks

1-phase, 500kV surge arresters 3 ea 52 wks **500kV station post insulators 50 ea 10 wks500kV substation bus and conductorfittings 1 lot 11 wks

5-inch, Sch 40 aluminum bus 710 ft 21 wks

230kV3-phase, 230kV, 3000A 63kA gascircuit breaker with two 3000-5A MRCT’s per bushing

1 ea 24wks

3-phase, 230kV, 3000A vertical breakdisconnect switch without groundingswitch

1 ea 24wks

3-phase, 230kV, 3000A vertical breakdisconnect switch with groundingswitch

1 ea 24wks

1-phase, 230kV surge arresters 3 ea 52 wks **230kV station post insulators 92 ea 10 wks230kV polymer suspension insulators 12 ea 16 wks230kV substation bus and conductorfittings 1 lot 11 wks

5-inch Sch 40 aluminum bus 1500 ft 21 wks1272 MCM ACSR 45/7 conductorstrain bus (bundled) 4500 ft 24 wks

15kV3-phase 15kV, 2000A, 40kA,Outdoor, Vacuum Circuit Breakerwith one 2000-5A MR CT perbushing

3 ea 24 wks

3-phase 15kV, 5400A, Double-sidebreak, gang operated switch 1 ea 24 wks

1-phase, 15kV surge arresters 6 ea 52 wks **6-inch Sch 40 aluminum bus 1720 ft 21 wks15kV station post insulators 75 10 wks15kV substation bus and conductorfittings 1 lot 11 wks

* Lead time as of January 7, 2002.** Arresters are purchased with and will be delivered with thetransformers. Normal lead-time is 16 weeks.



500kV YardThe Southeast node of the South 500kV ring will be used toconnect the new transformer bank. Breaker H, and two breakerisolation disconnect switches will need to be installed to completethe node. Once Autotransformer No. 2 is energized, a 500kVbreaker can be removed from the 500kV yard.

500/230kV Transformer No. 2The four new single-phase 500/230/13.8kV autotransformers willbe installed south of the 500kV ring bus. These transformers willbe arranged such that the spare fourth transformer can be energizedin the event of a failure of any one of the other three activetransformers via the rearrangement of the high, low and tertiarybus connections.

The 500kV bus to the transformer will require a transfer bus toallow any active phase to be reattached to the spare fourthtransformer in the event one of the three active transformers fails.Drawing GJ0021EA2IPPP shows the fourth phase as a low busunderneath and adjacent to the 500kV ring bus. The transfer buscan be attached to any of the three active phases by the use of apiece of straight vertical pipe between the phase to be transferredand the transfer bus using bolted fittings.

The 230kV and 13.8kV buses run parallel to the transformer bank.As a result, a fourth bus, acting as a transfer bus, will not berequired. The spare fourth transformer can be tied to the activephase position, by removing the X1, Y1 and Y2 bus pipe from thefailed transformer position and then moving it over to, and re-installing it on the X1, Y1 and Y2 positions of the sparetransformer.

The firewalls between the four transformers will be concrete blockmatching the firewall design used for the existing transformers atHartburg. The 500kV transformer arresters will be positioned infront of the firewalls on self-supporting steel.

Transformer units will have an oil containment system installed.

The existing cable trench from the 500kV yard will be extendedover to the new transformer bank. The trench is located betweenthe 13.8kV bus and the 230kV bus rather than directly adjacent tothe transformer bank. This is to allow ease of access to otherequipment in and around the transformers and the oil containmentpit, and to isolate the cables contained in the trench from damagedue to a fire or an oil spill.



A marshalling cabinet will be installed next to the transformerbank. This cabinet will provide a central connection point for alltransformer CT’s. When the fourth transformer is moved into aphase position, all CT cables will be reconnected at this cabinet.

230kV YardA new 230kV South Bus will be established to connect the newtransformer bank to the Helbig line. A 1272MCM ACSR, 2conductor per phase, strain bus will be used to provide the 2000-ampere capacity required between the new transformer bank andthe new South Bus. Breaker AA, isolation switches and a new lineswitch will be installed to complete the South Bus arrangement.

Once the South Bus is installed and is serving the Helbig line fromthe new transformer bank, the existing transformer bank, theexisting 230kV North Bus and all existing breakers and switcheswill be removed from service.

13.8kV YardThe existing stepped reactors are rated 11.6MVA at 7960 volts perstep per phase. With all three steps in-service, the total currentdraw by the reactors will be approximately 4300 amperes perphase. The most economical and efficient means to attach thetertiary of the new transformers to the existing reactors is via arigid bus. Therefore the design calls for the tertiary bus from thenew transformers to the existing step reactor banks and the stationservice transformer to be 6-inch rigid bus. To provide height foryard access underneath the bus between the reactor banks and thenew transformers and across the existing road, the estimate isbased on the use of 230kV standard steel structures. A 15kVgroup-operated switch has been added next to Transformer BankNo. 2 to provide isolation of the transformers from the tertiary busduring transformer maintenance.

The 3-phase short-circuit duty has increased to approximately28kA on the existing tertiary bus. As a result, the three existing15kV breakers protecting the reactor banks will have to bereplaced with 40kA units.

StationThe shielding over the existing 500kV yard will be extended tocover the new transformer bank. The static wire over the new230kV strain bus will provide protection for the 13.8kV tertiarybus. The addition of two masts and a static wire over the South



bus will protect the new 230kV South Bus. Shielding will beverified during detail design.

New AC and DC distribution panels will be installed next toBreaker AA.

Assumptions

• The development of this physical arrangement is based onkeeping the outage time of the Helbig Line to a minimum. Byadding Autotransformer No. 2 to a new bay, creating a newSouth Bus and a new 230kV breaker bay, all relay schemes forprotection of the new transformer can be completed and testedwithout an outage to Autotransformer No.1 and the Helbig line.

• The 230kV breaker is rated 63kA to accommodate the futureexpansion of the 230kV yard by the addition of othertransmission lines or the paralleling of a second transformerbank.

• The rating of the existing reactors is unknown. If the unitsrequire replacement, the replacement will impact the layout,installation and design of the 230/13.8kV yard.

b. SITE WORK

The following site work will be performed in the 230kV area:surveying, grading, excavation, fill and compaction.

Assumptions

• Wetlands permit for the south end of the yard will not berequired.

• An oil collection system will be required for the newtransformers.

• Site work estimates are based on the upgrade of an areacontaining approximately 216,000 sq. ft. Soil stabilization isbased on an assumed depth of 18-inches. The fill and compactrequirement is based on an assumed depth of 24-inches. Finallimestone surfacing requirement is assumed to be 6-inches overthe entire surface.



c. STRUCTURAL WORK

The following steel structures will be installed to support the newelectrical equipment and bus work:

STRUCTURES QUANTITY LEADTIME*

500kV1-phase, 500kV low bus support(lattice-1 per support) 14 ea 20 wks

1-phase, 500kV high bus support(lattice-1 per support) 18 ea 20 wks

Shield wire mast 5 ea 20 wks1-phase, 500kV CVT support (lattice-1 per support) 1 ea 20 wks

1-phase high surge arrester support 3 ea 20 wks

230kV3-phase, 230kV low disconnectswitch support (tube steel-1 persupport)

2 ea 26 wks

3-phase, 230kV low disconnectswitch support with adaptor for futureswitch (tube steel-1 per support)

2 ea 26 wks

3-phase, 230kV dead-end A-framestructure (tube steel-1 per support) 2 ea 26 wks

1-phase, 230kV dead-end polestructure (polygon steel-1 per support) 3 ea 26 wks

1-phase, 230kV low bus support(lattice-1 per support) 12 ea 26 wks



1-phase, 230kV CVT support (lattice-1 per support) 3 ea 26 wks

15kV3-phase, 15kV high bus support,(Note: 230kV bus supports will beused for this application) (lattice-1 persupport)

8 ea 20 wks


3-phase, 15kV high disconnect switchsupport (tube steel-1 per support) 1 ea 20 wks




3-phase high PT stand 1 20 wks* Lead time as of January 7, 2002.

d. FOUNDATION WORK

The following foundations will be installed to support the newelectrical equipment and bus work:

FOUNDATIONS QUANTITY500kV1-phase, 500/230/13.8kV autotransformer bankfoundation (1 spread footing per transformer) 4 ea

3-phase, 500kV gas circuit breaker foundation(spread footing - 1 per phase) 3 ea

1-phase, 500kV low bus support foundation(drilled pier – 1 per support) 14 ea

1-phase, 500kV high bus support foundation(drilled pier – 1 per support) 18 ea

Oil collection system 1 lotFire wall between 1-phase transformer tanks 3 eaShield wire mast foundation (drilled pier – 1 persupport) 5 ea

1-phase, 500kV CVT support foundation (drilledpier – 1 per support) 1 ea

1-phase 500kV surge arrester support 3 ea

230kV3-phase, 230kV gas circuit breaker foundation(spread footing - 1 per breaker) 1 ea

3-phase, 230kV low disconnect switch supportfoundation (drilled pier-2 per support) 2 ea

3-phase, 230kV low disconnect switch supportfoundation with adaptor for future switches(drilled pier-2 per support)

2 ea

3-phase, 230kV dead end A-frame structurefoundation (drilled pier – 4 per structure) 2 ea

1-phase, 230kV self-supporting dead end polestructure foundation (drilled pier – 1 per support) 3 ea

1-phase, 230kV low bus support foundation(drilled pier-1 per support) 12 ea

3-phase, 230kV high bus support foundation(drilled pier-2 per support) 12 ea




FOUNDATIONS QUANTITY1-phase, 230kV CVT support foundation (drilledpier - 1 per support) 3 ea

15kV3-phase 15kV high switch stand (drilled pier – 2per support) 1 ea


3-phase, 230kV high bus support foundation(Note: 230kV bus supports will be used for thisapplication) (drilled pier-2 per support)

8 ea

3-phase PT stand (drilled pier – 1 per support) 1 ea

Assumptions

• Foundation design is based on the Southwestern LaboratoriesSoil Boring Report for Hartburg Substation dated March 23,2001 and its amendments.

• Boring B-12 was taken in the immediate area ofAutotransformer No. 2 and will provide adequate informationfor the design of the transformer foundations.

• Foundation size and depth of drilled piers for the 500kV yardto provide adequate lateral resistance and bearing capacity areassumed to be in the range of 12 to 15 feet.

• Foundation size and depth of drilled piers to provide adequatelateral resistance and bearing capacity for the 230kV yard areassumed to be in the range of 10 feet for the low profilestructures and up to 20 feet for the deadend structures.

e. RELAYING WORK

(See drawings GJ0021OP1IPPP and GJ0021OP2IPPP)

The following equipment will be installed to provide relayprotection and breaker control for the optional upgrades:

RELAYING EQUIPMENT QUANTITY LEADTIME*

500kVBreaker control panel (SEL-351) –new 500kV breaker 1 ea 18 wks



RELAYING EQUIPMENT QUANTITY LEADTIME*

Line relay panel – 500kV L-547 toCypress 2 ea 16 wks

Transformer differential panel,500/230/13.8kV Autotransformer No.2

2 ea 16 wks

500kV capacitive voltage transformer(CVT), for relaying 1 ea 16 wks

230kVBreaker control panel – new 230kVbreaker 1 ea 18 wks


13.8kV13.8kV potential transformer –autotransformer #2 tertiary bus 3 ea 14 wks

StationControl cable (inside control building) 1 lot 14 wksShielded control cable (outsidecontrol building) 1 lot 14 wks

Outdoor Junction boxes (Linerelaying CVT) 2 ea 8 wks

Outdoor AC Panel 1 ea 14 wksOutdoor DC Panel 1 ea 14 wks* Lead times as of January 7, 2002

500kV YardTwo new line relaying panels will be necessary for the 500kV L-547 Cypress line to accommodate the new ring bus arrangement atCypress. These panels will be located in the new control building,and will contain the control for line MOS 13202. The existing linerelaying panels will be removed.

The 500kV Bus No. 1 differential scheme as well as the breakerfailure schemes for several 500kV breakers will be modified as theresult of adding breaker H and removing breaker 13130.

A new 500kV breaker control panel will be installed in the newcontrol building for breaker H.

One new relaying CVT will be added on the 500kV node of thenew 500/230/13.8kV autotransformer.



The existing transformer protection panels will be removedfollowing the addition of the new 500/230/13.8kV transformer.The control panel for GCB 13130 will remain because it containsthe control switches for MOD 13129 and MOD 13552.

230kV YardThree new relaying CVT’s will be added on the 230kV node of thenew 500/230/13.8kV autotransformer. The existing single phaseCVT on the Helbig Line will be reused.

A new 230kV breaker control panel will be installed in the oldcontrol building for breaker AA.

Relaying for the 230kV Helbig L-195 line relaying will betransferred to new breaker AA from existing breaker 13135. Thecontrol panel for breaker 13135 will be removed.

13.8kV YardThree new 13.8kV PT’s will be installed on the tertiary bus of500/230/13.8kV Autotransformer #2 for over and undervoltageprotection.

The overcurrent relaying for the existing 13.8kV breakers islocated in the breaker cabinet. Since these breakers are to bereplaced, new overcurrent relaying will be required with the new13.8kV breakers.

Three new 13.8kV stand alone CT's will be installed on the tertiarybus of Autotransformer #2 to provide current values for the newtransformer differential protection.

AutotransformersTwo transformer differential protection panels will be required toprovide dual primary differential protection for the new500/230/13.8kV transformer. These panels are also to include500kV and 230kV backup overcurrent relaying, and 13.8kVtertiary over and undervoltage relaying. The new transformerprotection panels will be located in the old control building.

StationA new outdoor AC panel and outdoor DC panel will be requiredfor the new 230kV yard equipment.



Assumptions

• The RTU being installed for the mandatory work will beadequate for the optional work.

• Existing line relaying for 230kV L-195 to Helbig is adequatefor the new arrangement.

• Entergy or its designated contractor/consultant will provide theengineering for relay coordination and determination of theprotective relay settings. Entergy or its designatedcontractor/consultant will set the applicable relays and performrelay calibration, testing and checkout for all Entergy relays.

2. CYPRESS 500/230/138KV SUBSTATION

a. ELECTRICAL WORK

Please reference the following drawings for the work detailed inthis section GJ0021076IPPP, GJ0021FS3IPPP, GJ0021PP1IPPP,and G1210SO6IPPP.

ELECTRICAL EQUIPMENT QUANTITY LEADTIME*

500kV1-phase, 500/230/13.8kv,150/200/250MVA AutotransformerNo. 3

3 ea 52wks

3-phase, 500kV, 3000A 63kA gascircuit breaker with three 3000-5AMR CT’s per bushing for relaying.

3 ea 58wks

3-phase, 500kV, 3000A motoroperated vertical break disconnectswitch without grounding switch

3 ea 32

1-phase, 500kV, arresters 3 ea 52 wks **500kV station post insulators 162 ea 10 wks3000A 5-inch aluminum bus, sch 40 4000 ft 21 wks500kV substation bus and conductorfittings 1 lot 11 wks

230kV3-phase, 230/138/13.8kV, 300MVAAutotransformer No. 4 with LTC 1 ea 52 wks

3-phase, 230kV, 3000A, 63kA gascircuit breaker with two 3000-5A MRCT’s per bushing

4 ea 24 wks



ELECTRICAL EQUIPMENT QUANTITY LEADTIME*


8 ea 24 wks

3-phase, 230kV, 3000A motor-operated, vertical break disconnectswitch with grounding switch

3 ea 24 wks

1-phase 230kV surge arresters 6 ea 52 wks **230kV suspension insulators(polymer) 6 ea 12 wks

230kV station post insulators 428 ea 10 wks3000A 5” aluminum bus, Sch 40 3800 ft 21 wksBus and conductor fittings 1 lot 11 wks954 MCM ACSR 45/7 conductorstrand strain bus 500 ft 24 wks

138kV3-phase, 138kV, 3000A, 63kA gascircuit breaker with two 3000-5A MRCT’s per bushing

4 ea 24 wks


8 ea 24 wks

230kV station post insulators 81 ea 10 wks230kV polymer suspension insulators 12 ea 12 wks3000A, 5-inch aluminum bus, Sch 40 360 ft 21 wksbus and conductor fittings 1 lot 11 wks1272MCM ACSR 45/7 strandconductor strain bus 2000 ft 24 wks

1-phase 138kV surge arresters 3 ea 52 wks **

15kV15kV insulators 18 ea 18 wks1-phase surge arresters 6 ea 52 wks **6-inch, Sch 40 Aluminum bus 330 ft 21 wksBus and conductor fittings 1 lot 11 wks

Battery building (240 sq ft) 1 ea 12 wks* Lead times as of January 7, 2002** Arresters are purchased with and will be delivered with thetransformers. Normal lead-time is 16 weeks.



500kV yardThe existing 500kV radial feed from the Hartburg Substation willbe expanded into a ring bus to provide the source node for the new500/230kV Autotransformer No. 3. Breakers A1, A2 and A3 willbe added along with the switches and bus work necessary to createthe ring.

The new 500/230kV Transformer Bank No. 3 will be locatedadjacent to the existing 500/138kV Autotransformer Bank No 1. Aconcrete block wall will be placed on each side of the center unit toprovide a fire barrier between each unit in the event one of theunits should fail and catch on fire. The tertiary on each unit hasbeen brought out of the tank. A 3-phase, 6-inch rigid bus will berun along the top of the fire walls to connect the tertiary windingsinto a delta. There are no plans to use the tertiary windings toserve a load at this time.

230kV YardThe existing 230kV yard will be expanded into a 4-position ringbus using a layout that can ultimately be expanded into a breaker-and-a-half scheme. Breakers B1, B2, B3, and B4 with theirassociated isolation switches will be added to the ring to provideseparate bays for the existing Amelia Line, existingAutotransformer No. 2, and new Autotransformer No. 3 and No. 4.

A new 230/138kV, 300MVA transformer bank will be added toprovide increased capacity between the 230kV and the 138kVyards. A 230kV motor-operated switch will be provided on theprimary side of the transformer so the 230kV ring bus can beisolated from the transformer and the ring closed in the event of atransformer failure. The new transformer bank is being purchasedwith an LTC and all equipment necessary to put in-service anautomatic paralleling scheme between Autotransformer No. 2 andNo. 4. The tertiary has been brought out of the tank. Since thereare no plans to use the tertiary to serve a load the tertiary bushingswill be connected to 15kV arresters only.

Low profile rigid bus will be used to tie Autotransformer No. 3 to anew 230 bay between breakers B1 and B2. The existing 230kVAmelia line will have a motor-operated line switch added so theline can be isolated from the ring and the ring closed in the eventof a line failure.

138kV YardThe 138kV yard will be expanded to a breaker-and-a-half schemeby the addition of Breakers C1, C2, C3 and C4 and their associated



isolation switches. After completion of these upgrades, eachexisting line, Autotransformer No. 2 and Autotransformer No. 4will have their own line bay. The breaker-and-a-half scheme isnecessary to provide assurances that the failure of any singlebreaker in the 138kV yard will not cause the simultaneous loss oftwo of the three transformers connected to the 138kV yard.

A strain bus will be used to connect Autotransformer No. 4 to theline bay between 138kV breakers C2 and C3.

StationA small auxiliary battery building will be added next to theexisting control building. The battery room in the present buildingis too small to add a second 125Vdc battery set. The batterybuilding will be a self-supporting, pre-engineered building, sizedjust to contain the new battery set. The chargers, and DC panelsassociated with the new battery set will be installed in the existingcontrol building.

The existing station shielding uses a combination of 170-footmasts and shield wires. The number and location of new mastsshown is based on the use of this system. Several masts arerequired to cover the area being developed by the expansion of thethree yards. Shielding will be verified during detail design.

Assumptions

• Oil containment will not be required at this station

• Two of the existing switch racks have bent switch platforms.We are assuming that these platforms do not need to bereplaced, but can be straightened by adding additional bracing.

• The 138kV yard is built using 230kV switches, and high-strength insulators. Only the breakers are rated 138kV. Allnew equipment is specified to match the existing design.

• A 138kV, 63ka GCB requires a larger bay area than a 40kAGCB because of the capacitor attached to acquire the 63kArating. It is assumed that the existing bay space in the 138kVyard is adequate for the new breakers and that existing switchstands will not have to be moved to provide adequate space.



SITE WORKThe following site work will be performed in the 500kV and230kV area: surveying, grading, excavation, fill, compaction andthe addition of a second gate at the entry road.

Assumptions

• Wetlands permit will not be required for this site.

• The storage yard fence will have to be relocated toaccommodate the extension of the station road to the south.The gate and access to the yard may have to be moved as well.

• All roadways associated with the delivery of new transformerunits will require upgrading.

• Site work estimates are based on the upgrade of an areacontaining approximately 378,000 sq. ft. Soil stabilization isbased on an assumed depth of 12-inches. The fill and compactrequirement is based on an assumed depth of 18-inches. Finallimestone surfacing requirement is assumed to be 6-inches overthe entire surface.

c. STRUCTURAL WORK

The following structures will be installed to support the newelectrical equipment, bus work, and transmission line termination:


500kV3-phase, 500kV high disconnectswitch support (lattice-6 per switch) 3 ea 20 wks

3-phase, 500kV low disconnect switchsupport with adaptor for futureswitches (lattice-6 per switch)

3 ea 20 wks

3-phase, 500kV high disconnectswitch support with adaptor for futureswitches (lattice-6 per switch)

3 ea 20 wks

1-phase, 500kV low bus support(lattice-1 per support) 48 ea 20 wks


1-phase, 500kV arrester support(lattice-1 per support) 3 ea 20 wks




Shield wire mast (lattice-1 perstructure) 11 ea 20 wks

1-phase, 500kV CVT support (lattice-1 per support) 3 ea 20 wks

230kV3-phase, 230kV low disconnect switchsupport (tube steel-1 per support) 10 ea 26 wks

3-phase, 230kV low disconnect switchsupport with adaptor for future switch(tube steel-1 per support)

4 ea 26 wks


1-phase, 230kV low bus supportstructure (tube steel-1 per support) 40 ea 26 wks

1-phase, 230kV high bus supportstructure (tube steel-1 per support) 10 ea 26 wks

3-phase, 230kV high bus supportstructure (tube steel-1 per support) 58 ea 26 wks

1-phase, 230kV CVT supportstructure (tube steel-1 per support) 4 ea 26 wks

138kV3-phase, 230kV low disconnect switchsupport (tube steel-1 per support) 4 ea 26 wks


1-phase, 230kV low bus supportstructure (tube steel-1 per support) 9 ea 26 wks

1-phase, 230kV CVT supportstructure (tube steel-1 per support) 3 ea 26 wks

13.8kV3-phase high bus support 4 26 wks3-phase high PT support 1 26 wks

* Lead time as of January 7, 2002.

Assumptions

• A motor-operated line switch must be added to the Amelia line.We assume that the existing deadend has been designed toallow for the addition of this switch.



• Switch structures, with solid bus across them, will be used inthose locations where the switches are shown as future.

• Two existing 138kV switch support structures can be reused ifvertical bracing is provided for the horizontal beams.

• The 138kV yard is built using 230kV steel and deadends. Onlythe breakers are rated 138kV. All new steel and deadends arespecified to match the existing design.

• The estimate calls for three 230kV deadend structures for thestrain bus from the 138kV yard to the new 300MVATransformer No. 4. If the analysis of the steel will allow thestrain bus to span the 138kV East Bus and the 230kV rigid busbetween Autotransformer No. 3 and the 230kV yard, then onedeadend can be removed.

d. FOUNDATION WORK

The following foundations will be installed to support the newelectrical equipment and bus work:

FOUNDATIONS QUANTITY500kV1-phase, 500/230/13.8kV autotransformer bankfoundation (1 spread footing per transformer) 3 ea

3-phase, 500kV gas circuit breaker foundation(spread footing - 1 per phase) 9 ea

3-phase, 500kV high disconnect switch supportfoundation (drilled pier – 6 per support) 3 ea

3-phase, 500kV low disconnect switch supportfoundation with adaptor for future switches(drilled pier – 6 per support)

3 ea

3-phase, 500kV high disconnect switch supportfoundation with adaptor for future switches(drilled pier – 6 per support)

3 ea

1-phase, 500kV low bus support foundation(drilled pier – 1 per support) 48 ea

1-phase, 500kV high bus support foundation(drilled pier – 1 per support) 51 ea

1-phase, 500kV arrester support foundation(drilled pier-1 per support) 3 ea

Shield wire mast foundation (drilled pier – 1 persupport) 11 ea

1-phase, 500kV CVT support foundation (drilledpier – 1 per support) 3 ea



FOUNDATIONS QUANTITY

230kV3-phase, 230/138/13.8kV autotransformerfoundation 1 ea

3-phase, 230kV gas circuit breaker foundation(spread footing - 1 per breaker) 4 ea


3-phase, 230kV low disconnect switch supportfoundation with adaptor for future switches(drilled pier-2 per support)

4 ea





1-phase, 230kV CVT support foundation (drilledpier - 1 per support) 4 ea

138kV3-phase, 138kV gas circuit breaker foundation(spread footing - 1 per breaker) 4 ea




1-phase, 230kV CVT support foundation (drilledpier - 1 per support) 3 ea

15kV3-phase high bus support (drilled pier – 1 persupport) 4 ea

3-phase high PT support (drilled pier – 1 persupport) 1 ea

Battery Building (spread footing) 1 ea



Assumptions

• The firewalls between the new transformers will be blockwalls. The block wall structure estimate is based on the wallinstalled at Hartburg Substation shown on Drawing No.G1167285.

• The expansion of the 230kV yard will include switch structuresin those areas where the breaker isolation switches are future.Foundations for deadend structures will not be added in thoselocations where the line bays are future.

• Instrument and arrester foundations will not be added in thoseareas of the 230kV and 138kV yards where the line deadendsare indicated as future.

• Soil report indicates a soft layer near the surface of the yard.Soil analysis during design may require the actual foundationsto be deeper to compensate for this condition.

• Foundation depth for drilled piers for the 500kV yard areassumed to be in the range of 12 to15 feet to provide adequatelateral resistance and bearing capacity.

• Foundation depth of drilled piers for the 138kV and 230kVyard are assumed to be in the range of 10 feet for low profilestructures and up to 20 feet for the deadends to provideadequate lateral resistance and bearing capacity.

e. RELAYING WORK

(See drawings GJ0021OP3IPPP, GJ0021OP4IPPP,GJ0021OP5IPPP, and GJ0021SK2IPPP)

The following equipment will be installed to provide relayprotection and breaker control for the optional upgrades:

PROTECTION EQUIPMENT QUANTITY LEADTIME*

500kVTransformer differential panel, –500/138kV Autotransformer No. 1 2 ea 16 wks

Transformer differential panel, –500/230/13.8kV Autotransformer No.3

2 ea 16 wks




Breaker control panels (SEL-351) –new 500kV breakers 3 ea 18 wks

Line relay panel – 500kV L-547 toHartburg 2 ea 16 wks


230kVTransformer differential panel, –230/138/13.8kV Autotransformer No.2

2 ea 16 wks

Transformer differential panel, –230/138/13.8kV Autotransformer No.4

2 ea 16 wks

Breaker control panel (SEL-351) –new 230kV breakers 4 ea 18 wks


138kVBus differential panel – for East andWest 138kV Busses 2 ea 16 wks

Breaker control panel (SEL-351) –new 138kV breakers 4 ea 18 wks


13.8kV13.8kV potential transformer –autotransformer #3 tertiary bus 3 ea 14 wks

StationControl cable (inside control building) 1 lot 14 wksShielded control cable (outsidecontrol building) 1 lot 14 wks

Stand alone AC panel 1 ea 14 wksStand alone DC panel 2 ea 14 wksOutdoor DC panel 3 ea 14 wksOutdoor AC panel 3 ea 14 wksOutdoor 480V-240/120V AC 3 phasestation service transformer 4 ea 16 wks

125VDC, 440AH Battery Set andRack 1 ea 16 wks




50A battery charger 1 ea 16 wks200A battery test switch panel 2 ea 16 wksOutdoor Junction boxes (2–Busrelaying CVT, 7-Line relaying CVT) 9 ea 8 wks

Indoor Junction boxes (Bus potentialdistribution box) 2 ea 8 wks

GE Harris D20 RTU 1 ea 16 wksTeltone SLSS Line Sharing Switch 1 ea 8 wksSEL-2030 Communications Processor 2 ea 8 wksSEL-Starcomm Modem 2 ea 8 wksGE-Harris Telenetics Modem 1 ea 8 wks

* Lead time as of January 7, 2002.

500kV YardTwo relaying CVT’s will be installed on the 500kV bus at the highside of autotransformers #1 and #3. One relaying CVT will beinstalled on the 500kV Hartburg line on the line side of the switchto provide voltage sensing.

Two new line relaying panels will be necessary for the 500kV L-547 Hartburg line to accommodate the new ring bus arrangement.

There will be two new stand alone DC panels (one on each batterybank) and one new stand alone AC panel placed in the controlbuilding to serve the new 500kV equipment, including transformer#3. To provide voltage support in the yard, we will locate a new480V-240/120V station service transformer. The 480V input forthis transformer will be fed from the existing 480V AC panels.This local transformer will be served from the new panels locatedin the Control Building.

230kV YardThree new relaying CVT’s will be installed on the 230kV bus, onefor the low side of autotransformer #3, and two for the high side ofautotransformers #2 and #4. Additionally, one CVT will be addedto the 230kV Amelia L-488 on the line side of the line disconnectswitch to provide voltage sensing.

The existing 230kV L-488 to Amelia relaying will be maintained,and moved to the appropriate new breakers in the 230kV ring bus.

There will be one new outdoor DC panel and one new outdoor ACpanel placed in the 230kV yard for the new equipment. To providevoltage support in the yard we will locate a new 480V-240/120V



station service transformers. The 480V input for this transformerwill be fed from the existing 480V AC panels. This localtransformer will be served from the new panels located in theControl Building

138kV YardWith the 138kV additions to make a breaker-and-a-half scheme,there will be two 138kV bus differential protection panels required,one for each bus. Additionally, the existing 138kV breakercontrols will be modified to support the new breaker and a halfscheme.

There will be two new outdoor DC panels and two new outdoorAC panels placed in the 138kV yard for the new equipment. Toprovide voltage support in the yard we will locate a new 480V-240/120V station service transformers. The 480V input for thistransformer will be fed from the existing 480V AC panels. Thislocal transformer will be served from the new panels located in theControl Building

13.8kV YardThree new 13.8kV PT’s will be installed on the tertiary bus of500/230/13.8kV Autotransformer #3 for over and undervoltageprotection.

AutotransformersThe new 500/230/13.8kV and 230/138/13.8kV transformers willeach be required to have dual primary differential protection. Theexisting 500/138kV and 230/138kV transformer relaying will needto be replaced with new transformer protection panels to supportthe new substation configuration. Therefore, the relaying for thetwo new and the two existing transformers will all be identical,with the exception of the tertiary protection required for500/230/13.8kV autotransformer #3. Each transformer will havedual primary transformer differential, high side overcurrent, andlow side overcurrent protection, and will require two new panelseach.

The existing 500/138kV autotransformer #1 revenue meteringpanel will be removed.

StationAll new 500kV, 230kV, and 138kV breakers will require a breakercontrol panel to be added, utilizing the SEL-351 relay. The SEL-351 will provide synchronizing supervision for the new breakers.



The existing 138kV breakers utilize a sync scope and anautosynchronizing relay scheme to supervise closing of eachbreaker. This equipment will remain, and new breakers will beadded to the existing sync scope for manual synchronizing if thenew panel is in the same panel lineup.

A new GE-Harris D20 RTU will replace the existing RTU. Allpoints on the existing annunciators will be moved, point-to-point,to the new RTU, and the annunciators removed upon completion.The new RTU will be required to communicate with the TOCsimultaneously with the existing RTU during construction, andwill therefore require an additional data circuit.

The new 500kV breakers will have trip coil #1 and trip coil #2supplied by two independent 125VDC battery sets. The existing138kV breakers will operate as they are currently connected on theexisting battery set. The existing 125VDC battery set will supplythe new 138kV breakers. The new 125VDC battery set will supplythe new 230kV breakers.

All new relaying will have primary and backup relays separatedbetween new and existing 125VDC battery sets. Existing relayingwill be supplied as currently connected.

The new 125VDC panels will be sized to provide enough polepositions for separation of trip coil #1 and trip coil #2 for the138kV breakers in the future.

All new and existing breakers in the 138kV yard will use theexisting battery set. The 230kV yard will be connected to the newbattery set. The 500kV yard will use both battery sets.

A new Teltone Substation Line Sharing Switch (SLSS), two newcommunications processors, and associated modems will be addedto provide remote access to the new relaying equipment and RTU.

Assumptions

• There is sufficient space in the existing control building for allnew protection panels, AC and DC panels, andcommunications equipment.

• Existing line relaying for all 138kV lines and 230kV L-488 toAmelia is adequate for the new arrangement.



• Entergy or its designated contractor/consultant will provide theengineering for relay coordination and determination of theprotective relay settings. Entergy or its designatedcontractor/consultant will set the applicable relays and performrelay calibration, testing and checkout for all Entergy relays.

• New synchronizing scope panels are not necessary for newbreakers for Entergy operational use.

• The existing microwave system has sufficient capacity tosupport the additional channels needed for communication withthe TOC.

• The Entergy System Operations Center (SOC) will not requirea separate data circuit to be added for RTU information.

• The existing 300kVA station service transformer is rated tohandle new equipment loads in addition to the existing loads.

B. TRANSMISSION LINES

There is no optional transmission line work designated in this study.

4. COST ESTIMATE SUMMARY

SYSTEM UPGRADES

The total cost for the system upgrades that is optional work islisted below:Hartburg 500/230kV Substation $16,730,464Cypress 500/230/138kV Substation $27,836,668

TOTAL COST

Total cost for the OPTIONAL work above is:$44,567,132

The quantities of materials listed in this document are approximate and could changewith completion of detail design. The costs include taxes, overheads, but notAFUDC. Note: if progress payments are not completed, AFUDC will be added.

5. SCHEDULE MILESTONES

Entergy will make commercially reasonable efforts to complete this project to meetyour requested in-service date. The project durations outlined below are based on



the existing executed Interconnection and Operating agreement. We also note thatthe ability of Entergy to schedule power outages on its substation and transmissionsystems is very limited year-round and not possible at all during peak summermonths (June 1 through to September 30). Further, by regulation, availabletransmission transfer capacity is committed up to thirteen months in advance and thiscould limit outage capabilities. Finally, long lead times for critical materialsidentified in this schedule are based on current lead times offered by our suppliersand are subject to change with the commitment of actual purchase orders. For theseand other reasons, Entergy cannot guarantee the completion date of therequired or optional system improvements, regardless of when the customerexecutes an Interconnection and Operating agreement.

HARTBURG 500/230KV SUBSTATION

The estimated total project duration for the optional work is approximately 12months.

DESCRIPTION ACTIVITYDURATIONS

Site Work Design Package 6 wksFoundation Design Package 9 wksElectrical Design Package 14 wks

Relay Design Package 16 wksRelay Settings Package 10 wksSite Preparation Construction 6 wksFoundation Construction 16 wksElectrical Construction 18 wksRelay Construction 18 wks

CYPRESS 500/230/138KV SUBSTATION

The estimated total project duration for the optional work is approximately 19months.


Site Work Design Package 10 wksFoundation Design Package 14 wksElectrical Design Package 24 wks

Relay Design Package 26 wksRelay Settings Package 15 wks




Site Preparation Construction 8 wksFoundation Construction 18 wksElectrical Construction 20 wksRelay Construction 26 wks

** The construction will be performed in stages in order to ensure the earliestpossible energization date.

6. OUTAGE REQUIREMENTS

SYSTEM UPGRADES

All outages must be coordinated by the Entergy Construction Manager and approvedby Entergy System Operations.

The actual sequence and duration of any outage will be determined by Entergy andmay or may not follow the outline below.

Any additional costs required to install, and later remove, any temporary alternatefeeds to facilitate permanent line or station construction outages are not included inthis study, unless specifically noted.

HARTBURG 500/230KV SUBSTATIONOutage

IdOutage

Description Work Description OutageStart Date

Duration(Days)

1

Install BreakerH & ConnectXfmr 2 to500kV Bus

Open 13630 and MO 13553.Connect Xfmr 2, diffscheme to H. Connect Xfmr2 to 500V bus.

Leave GCB 13630 open

7

2No-load TestTransformer No.2

Close H & 13630, andenergize Xfmr 2. Testtransformer 2.

5000A, 13.8kV Sw. XXXXand GCB AA remain open

3

3Move Helbigline to SouthBus.

Open13135 and AA. MoveHelbig line to south bus.

Close AA and leave 13135open.

2



OutageId

OutageDescription Work Description Outage

Start DateDuration

(Days)

4

De-energizeXfmr 1.Remove breaker13130.

Open 13125 and MO 13552.Remove Xfmr 1 HV/LVjumpers. Add GCB H BFscheme to 13125. RemoveXfmr 1 relaying from 13125& 13560. Connect Xfmr 2tertiary bus to step reactors

Close 5000A 13.8kV SwXXXX, GCB 13125 andMO 13552

7

CYPRESS 500/230/138KV SUBSTATIONOutage

IdOutage

Description Work Description OutageStart Date

Duration(Days)

1

Install Xfmr 4strain bus andbreakers C2 &C3

Open Sw 22081 & OCB22050 (de-energize the EastBus). Set Xfmr 4 DEbetween C2 & C3. Pullstrain bus over East Bus.Set bus-side disconnects for22050, C2 & C3. Set andconnect East Bus CVT.

Leave jumpers off between138kV bus and Strain Bus

5

2 Install C4 andconnect to C3

Open 22070 & 22040 (de-energize West Bus). InstallC4 and C4 bus-side & lineside switches. Install busbetween C3 and C4. InstallWest Bus CVT. Add WestBus Diff scheme to 22070,22040 & C4. Modify BFscheme 22070 & 22040 toinclude C4.

5

3 Install C1

Open Sw 22081, 22050 &C2 (de-energize West Bus).Set GCB C1. Install EastBus Diff scheme. ModifyBF for C1, C2, 22075 &22050.

5



OutageId

OutageDescription Work Description Outage

Start DateDuration

(Days)

4

Install BreakerB3 & Lineswitch for L-488

Energize Xfmr 4

Energize Xfmr 2

Open 22075 and C1. (de-energize Xfmr 2 and line L-488). Set B2 bus-sideswitch, B3 and both B3isolation switches.Complete BF schemebetween B2, B3 & C1. SetInstall L-488 line switch.Establish Line L-488 linerelays on breaker B3 & B4.Place Auto # 4 in serviceusing line L-488.

Install strain bus jumpers.Close B3 and B4. TestXfmr 4. Close C2 and C3

Continue to re-work AutoNo. 2 relay scheme. PlaceAuto No. 2 back in service.

L-488 –5 days

Auto #2– 10 days

5

Install breakerA2 Close 500kVring.

Energize Xfmr 3

Modify Xfmr 1protectionschemes

Open 2045, 22050 and Sw22038 (de-energize Hartburgline L-547 and Xfmr 1). Setbreaker A2. . Reconnectline CT’s from Xfmr 1 CT’sto GCB’s A1 & A2.Connect 22026 to GCB A3

Close GCB A1 and test newtransformer

Complete 500/138kV AutoNo. 1 diff and BF schemesbetween A2, A3 22045 &22050.

Close A2, A3, 2045 &22050

Hartburgline – 2

days

Xfmr 1 –10 days



ATTACHMENTS

Hartburg 500/230/13.8KV Substation

DESCRIPTIONGJ0021EA1IPPP Hartburg 500kV Substation – Existing Station Arrangement

GJ0021EA2IPPP Hartburg 500kV Substation – Proposed Station ElectricalArrangement

GJ0021FS1IPPP Hartburg 500kV Substation – Proposed 230kV Facility StudyOne Line

GJ0021FS2IPPP Hartburg 500kV Substation – Facility Study One Line

GJ0021OP1IPPP Hartburg 500kV Substation – Proposed 230kV RelayOperational One Line

GJ0021OP2IPPP Hartburg 500kV Substation – Proposed 500kV RelayOperational One Line

G1167SO5IPPP Hartburg 500kV Substation – Existing Station One LineG1167SO6IPPP Hartburg 500kV Substation – Existing Station One Line

Cypress 500/230/138KV Substation

DESCRIPTIONGJ0021076IPPP Cypress 500/230/138kV Substation Existing Property Plan

GJ0021FS3IPPP Cypress 500/230/138kV Substation – Proposed Facility StudyOne Line

GJ0021OP3IPPP Cypress 500/230/138kV Substation – Proposed 138kVOperational One Line

GJ0021OP4IPPP Cypress 500/230/138kV Substation – Proposed 230kV RelayOperational One Line

GJ0021OP5IPPP Cypress 500/230/138kV Substation – Proposed 500kVOperational One Line

GJ0021PP1IPPP Cypress 500/230/138kV Substation – Proposed Property andLocation Plan

GJ0021SK1IPPP Cypress 500/230/138kV Substation – Partial System Map

GJ0021SK2IPPP Cypress 500/230/138kV Substation – CommunicationsDiagram

G1210SO6IPPP Cypress 500/230/138kV Substation – Station One Line

customer: cottonwood energy company, lp fac study optional.pdf · cottonwood energy company, lp...

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