Hardin Interconnection. Facilities Study

Transcription

1 Hardin Intercnnectin Facilities Study July 22, 2003 Electric Transmissin Planning 1

2 Table f Cntents Executive Summary...3 Intercnnectin Data...4 Intercnnectin Substatin Facilities...5 Intercnnectin Relaying Facilities...12 Intercnnectin Metering Facilities...18 Cst Summary 26 Appendix Listing Appendix A: Substatin Drawings Appendix B: Substatin Facilities Csts Appendix C: Relaying Csts Appendix D: Metering Schematic Appendix E: Hardin Aut Substatin Cnstructin Time 2

3 Executive Summary NrthWestern Energy ( NWE ) has cmpleted a Facilities Study fr intercnnectin f 109 MW f the Intercnnectin Custmer Prject at the Hardin Aut Substatin Intercnnectin Pint lcated in Big Hrn Cunty, MT. The Facilities Study cnsiders the facilities required t physically and electrically intercnnect the generatr high side bus with NWE s electric transmissin system in accrdance with the cnclusins f the System Impact Study and in accrdance with Gd Utility Practice. The study cnsiders the prpsed generatin prject in cnjunctin with all the Generatin Intercnnect prjects prir t the Intercnnectin Custmer s Prject in the NWE queue. The System Impact Study fund that the Intercnnectin Custmer Prject culd be cnnected t the 115 kv bus at the Hardin Aut Substatin intercnnectin pint described in the study prepared fr Intercnnectin Custmer by NWE n April 12, This reprt prvides a summary f Facilities Study results. NWE is respnsible fr maintaining acceptable system reliability, and we must be certain that any degradatin f system reliability as a result f cnnecting the Intercnnectin Custmer Generatin Prject is within the tlerances f NWE and reginal perfrmance criteria. The Facilities Study is intended t prvide the preliminary design layut, transmissin system upgrade and cnstructin ruting infrmatin, majr equipment specificatins, and clear delineatin f respnsibility fr facilities installatin; an estimate f the cst t install the Transmissin Prvider Intercnnectin Facilities and Intercnnectin System Upgrades; and an estimate f the schedule t cmplete the installatin f the Transmissin Prvider Intercnnectin Facilities and Intercnnectin System Upgrades. Any deviatin frm the generatr design r intercnnectin specificatins prvided t us may cause the results f this analysis t becme inaccurate. If any Generatin Intercnnect prjects senir t the Intercnnectin Custmer Generatin Prject in the NWE queue chse t drp frm the queue, the results f this analysis may becme inaccurate. Additinal studies may have t be cmpleted t address items nt cvered in the Cexisting System Impact Study and this Facilities Study. This Facilities Study des nt cnstitute a request fr transmissin service. This study examines the physical intercnnectin f the Intercnnectin Custmer generatr t the electrical system and des nt imply that Intercnnectin Custmer will receive any transmissin required t deliver the generatin utput t the lad. Intercnnectin Custmer must fllw the prcedures described in the transmissin tariff available n NWE s OASIS site ( t request and/r reserve transmissin service. Intercnnectin Custmer is respnsible fr ensuring all WECC criteria, plicy, and guidelines are satisfied. The estimated csts and schedules may be adjusted if a reginal review cmmittee is frmed as part f btaining WECC certificatin f the remedial actin schemes. 3

4 Intercnnectin Data The basic prpsed generatr and intercnnectin infrmatin used in these studies includes: Prject Name Hardin Generating Prject Size (Rating) MW (109 MW Net t system) Thermal Cal Fired Generatr Generatr Type Synchrnus, wye cnnected, cal fired thermal generatrs. Fuel - Cal Lcatin Hardin Aut Substatin (Big Hrn Cunty, MT) Prpsed Cmmercial Operatin Date September, 2004 Facilities Cnnectin t the 115 kv transmissin line at the Hardin Aut Substatin Pwer Factr -.85 Excitatin System ESST4B Pwer System Stabilizer PSS2A (dual input) Transfrmer Generatr Step-Up, Three-phase, Wye Cnnected, 60 Hertz 4

5 Intercnnectin Substatin Facilities The Hardin Aut Substatin One Line drawing and Hardin Substatin Physical Layut are shwn in Appendix A. The existing 115 kv bus will be extended t the suth part f the substatin where it will meet the 115 kv line that is being cnstructed by Intercnnectin Custmer. An air break switch, 115 kv SF6 breaker and metering equipment will be installed within the NrthWestern Energy Substatin. The Pint f Intercnnectin will be where the NWE 115 kv bus meets the NWE substatin side f the insulatrs n the Intercnnectin Custmer air break switch. LAND: There are n additinal land requirements at Hardin Aut Substatin. The land required t cmplete the prject as prpsed, is already wned by NrthWestern Energy. RIGHT OF WAY (EASEMENTS): There will be n easements btained fr NrthWestern Energy s wrk. SURVEY: The surveying assciated with NrthWestern Energy s Substatin facilities will be dne internally. NrthWestern Energy has n staff a licensed prfessinal land surveyr. FENCE: There will n changes in the existing substatin fence at Hardin Aut Substatin. The existing fence is 7 tall with 3 strands f barbed wire acrss the tp. The existing fence is tied t the grund mat in accrdance with NrthWestern Energy s Substatin Design Standards. CONTROL HOUSE: 5

6 The existing cntrl huse is adequate, and meets NESC requirements, fr the additinal panels that will be installed by the Relay Department. YARD WORK: It will be necessary t haul ff excess materials and t gravel the sectins f the yard that are disturbed during cnstructin. The sil and subsil characteristics are knwn frm existing design files. N additinal getechnical wrk will be required t cmplete the engineering design f the electrical facilities. The access rad exists t the site and n additinal wrk is required. The site drainage exists and will nt require additinal wrk. Oil Cntainment is nt an issue fr this prject. The equipment additins assciated with this prject have little r n impact n the il vlume at this lcatin. There is adequate lighting in the existing facility. N additinal lighting will be installed. FOUNDATIONS: The ttal cncrete vlumes assciated with this prject are estimated at 90 cu. Yards. The breakdwn is as fllws: Spread Ftings assciated with ne dead-end twer Dwg B. Intercnnectin Custmer will wn this fundatin. NrthWestern Energy will design and install the fundatins. Flat pad with piers underneath assciated with ne 121 kv pwer circuit breaker - Dwg B5. Intercnnectin Custmer will wn this fundatin. NrthWestern Energy will design and install the fundatin. Spread ftings assciated with 25 bus supprt twers - Dwg B3. NrthWestern Energy will wn these ftings. Spread ftings assciated with 3 air break switch structures - Dwg B3. The ftings assciated with 2 f the air break switches will be wned by NrthWestern Energy. Intercnnectin Custmer will wn the ftings assciated with the third air break switch. NWE will design and install Intercnnectin Custmer s air break switch at the Hardin Aut Substatin. 6

7 Spread ftings assciated with CT s and PT s - Dwg B3. Intercnnectin Custmer will wn these ftings. NrthWestern Energy will design and install the fundatins. STRUCTURES: The ttal steel required fr this prject is 30,096 lbs. The structure details are as fllws: There will be ne 100 kv dead-end twer wned by Intercnnectin Custmer that the transmissin line will attach. The design parameters f the twer are as fllws: Maximum Tensin per phase is 7000#. Maximum Tensin per static is 4000#. Maximum # f phases is 3. Maximum # f static lines is 2. Maximum angle n the twer is 0 degrees. Height f phase cnductrs at attachment is 32 feet. Height f static cnductrs at attachment is 41 feet 6 inches. The phase spacing f the cnductrs is 10 feet and is hrizntal. The static spacing, if tw are used, is 26 feet. The NrthWestern Dwg. # is C. NrthWestern Energy will design and install the twer. There will be three Air Break Switch structures. The legs f the structures will be 9 feet. There is an arm that munts acrss tw legs that hlds all three ples f the air break switch and the inter-phase rds. The perating rd is munted dwn ne f the legs. The NrthWestern Dwg. # is C1 and C2. NrthWestern Energy will wn tw f the air break switches. Intercnnectin Custmer will wn the third air break switch. NWE will design and install all the structures in the Hardin Aut Substatin. There will be 27 Insulatr Supprt Twers. Seven twers will supprt a single insulatr and eighteen twer legs will be used t supprt nine arms with 3 insulatrs each. The twer heights will be 9-6. The NWE Dwg. # is B1 and B22. NWE will wn all the insulatr supprt twers. 7

8 There will be 6 twers t hld the Ptential Transfrmers (PT s) and the Current Transfrmers (CT s) assciated with the metering package. The twers will be apprximately 9 tall and will have munting plates n tp t hld the PT s and CT s. The NWE Dwg. # is B1 and B26. Intercnnectin Custmer will wn the twers assciated with the PT s and the CT s. NWE will design and install the twers. ELECTRICAL EQUIPMENT: Pwer Circuit Breaker Owned by RMP There will be ne 121 kv rated Pwer Circuit Breaker installed. The breaker must have the capability t interrupt a 10,000-amp fault. The breaker bushings can be n higher than 15 feet frm the base f the breaker. NWE will purchase and install the breaker. RMP will be billed fr the breaker and installatin. It has been requested that NWE purchase 2 additinal breakers fr the generatr end f the prject. NWE will purchase 2 additinal breakers and bill Intercnnectin Custmer accrdingly. Gang Operated Air Break Switches 2 wned by NWE and 1 wned by Intercnnectin Custmer These switches can be swing handle perated. The switches will be rated at 1200 amps. The switches will have a BIL rating f 550 kv. The switches will be V type. The switches will have TR 286 insulatrs. The switch wned by Intercnnectin Custmer must have a dual lcking device n the peratr. NWE will purchase and install all the air break switches. Intercnnectin Custmer will be billed fr 1 f the switches and installatin. Hk Operated Discnnect Switches Owned by Intercnnectin Custmer There will be 3 Hk Operated Discnnects, n the line side f the 121 kv pwer circuit breaker, munted n the dead-end twer. 8

9 The discnnects will be rated 1200 amp. The discnnects will have a BIL rating f 550 kv The discnnects will have TR286 insulatrs. The discnnects shuld have 90 degree stps. NWE will purchase and install the discnnects. Intercnnectin Custmer will be billed accrdingly. Instrument Transfrmers Owned by Intercnnectin Custmer There will be 3 CT s. There will be 3 PT s. These are t be dual winding secndary type. One winding t be used fr prtective relaying and ne t be used fr metering The instrument transfrmers must meet the requirements set frth in the Scping Dcument fr Revenue Metering. The instrument transfrmers will be tested at NWE s shp prir t installatin r as an alternative, can be tested n site. The nsite testing is mre expensive than testing the equipment in the shp. NWE will purchase and install the instrument transfrmers. Intercnnectin Custmer will be billed accrdingly. BUS WORK: The bus will be rated, and capable f carrying, 1200 amps. The bus will be 3 SPS 6063-T6 Aluminum pipe. The statin pst insulatrs will be standard strength TR286 insulatrs. The rigid pipe bus will be attached t the insulatrs using 3 pipe bus supprts (slip fits). The dead-end twer will have 3 cmpsite standard strength insulatrs with an verall length f 57. The insulatr will have Y-clevis-clevis end fittings. All bus wrk internal t the Hardin Aut Substatin will be designed and built by NWE. Intercnnectin Custmer will be billed accrdingly fr the prtin that they wn. 9

10 CONDUIT: Cnduit will be installed frm the electrical equipment t the cntrl huse. The cnduit will be 3 schedule 40 PVC. NWE will purchase and install all f the cnduit. Intercnnectin Custmer will be billed accrdingly fr the prtin that they wn. GROUND MAT: The grund mat will be added as necessary t prvide prper grunding fr all electrical equipment and steel structures. The grund grid is cmprised f 4/0 cpper interir t the substatin and 1/0 cpper as a perimeter grund arund the utside f the fence. All equipment is tied t the interir grund mat with 4/0 cpper. All steel structures are tied t the interir grund mat with a lp f 1/0 cpper. The fence is tied, at every furth pst, t the grund mat with 1/0 cpper. As part f the fence grunding, the 3-strand barbed wire tp is tied integrally t the grund mat. Grund rds will be added as needed in an effrt t reach a ttal grund mat resistance f 1 hm. All switches will have a grunded switching platfrm, fr peratr prtectin, at the perating pint. Intercnnectin Custmer will be billed fr the prtin f the grund mat that is required t adequately grund their structures and equipment. ENGINEERING & SUPERVISION: The engineering assciated with all additins inside f NWE s prperty will be dne internally, r by a NWE cnsultant, and reviewed and apprved by an engineer licensed in the State f Mntana. 10

11 CONSTRUCTION: The cnstructin f all facilities inside f NWE s prperty will be dne internally r by a NWE cntractr. NWE persnnel will supervise cnstructin. OPERATION AND MAINTENANCE: An peratinal and maintenance agreement will be signed due t the fact that Intercnnectin Custmer s facilities are lcated inside NrthWestern Energy s substatin fence. In additin, there will be a ne-time fee fr the use f space within the substatin. A cmplete listing f the NWE Equipment is given in THE Appendices. If the prject is authrized by July 1, 2003, the estimated cnstructin time t design and cnstruct the Substatin is apprximately 28 weeks frm July 20, The estimated date f cmpletin wuld be February 1, If the prject is authrized in the fall, this time will be extended due t the difficulty that may exist in installing Substatin Facilities. If grundwrk is required during the winter mnths, the estimate will need t be revised t accmmdate the increase in cst. Intercnnectin Custmer is t build, wn and perate the generatr step-up substatin, the 115 kv line frm the Intercnnectin Custmer plant t the dead-end twer at the Hardin Aut Substatin and all relaying and cmmunicatins assciated with the peratin and prtectin f the 115 kv line. NWE may cmment n areas that appear t be incrrect, r deficient, but will nt assume respnsibility fr the crrectness f prtectin pertaining t Intercnnectin Custmer s system. The Facilities wned by Intercnnectin Custmer must meet all applicable natinal, state, and lcal cnstructin and safety cdes. 11

12 Intercnnectin Relaying Facilities Hardin Aut Intercnnectin Custmer 115 kv Line Relaying Required The 115 kv line Relaying will be wned by Intercnnectin Custmer and Intercnnectin Custmer will be respnsible fr the design and installatin fr these facilities. NWE will install the relaying within the Hardin Aut Substatin. (Nte: Intercnnectin Custmer has indicated that they wuld like t cntract with NWE t design and install the relaying fr the 115 kv line t fulfill their requirements listed belw.) Line Differential The 115 kv line between Hardin Aut and Intercnnectin Custmer s generatin facilities will be prtected by redundant sets f line differential relaying as the primary relaying scheme. A fault n this line will trip PCB 100-XXX and the Intercnnectin Custmer plant breakers as apprpriate. Backup The 115 kv line backup relaying will be prvided by directinal phase and grund functins f the line differential relays. Reclsing Philsphy Reclsing is allwed n this line. A nminal tw-secnd-reclse time is NWE s standard. Intercnnectin Custmer shall prvide specific reclse lgic t NWE. Synch Check Nt required in the Hardin Aut Substatin n PCB 100-XXX. Plarizing Surce Three phase 115 kv ptential will be required within the Hardin Aut Substatin. PT s shall be wire-wund with dual secndary windings. 12

13 Cmmunicatins A cmmunicatins channel will be required between the Hardin Aut Substatin and Intercnnectin Custmer generatin facilities fr each line differential relay set. Dedicated fiber ptic pairs are the preferred cmmunicatins media. OPGW is preferred ver ADSS due t lwer prbability f damage. Hardin aut Substatin Relaying Required NWE will design and install. Bus Differential PCB 100-XXX will need t be incrprated int the new 115 kv high impedance bus differential. Its CT feeding int the bus differential will need t have a 400-vlt rating at the 600/5 tap. Generatin Relaying Required NWE will review the generatin prtectin package and verify that it cntains the fllwing prtectin devices: Phase/Grund Overcurrent Over/Under Frequency Over/Under Vltage Phase Sequence/Under Vltage Breaker Failure Intercnnectin Custmer shall prvide a breaker failure trip t PCB 100-XXX fr the failure f either BRK-001 r BRK-002. Generatr Backup 13

14 Generatr backup relaying shall be prvided by PCB 100-XXX line differential relays. Special Prtectin Schemes Required and Owned by Intercnnectin Custmer Remedial Actin Schemes (Stability/Vltage) A Remedial Actin Scheme is required that will trip Intercnnectin Custmer s Generatr within 10 cycles fr lss f bth Bradview t Garrisn 500 kv lines. Intercnnectin Custmer will be respnsible fr the design and installatin f the RAS, including the cmmunicatins, and securing the apprval frm WECC. NWE in cnjunctin with BPA will install the lgic at BPA s Garrisn Substatin and the Bradview 500 kv Substatin t determine the status f the 500 kv lines. Lgic fr this shall be lcated at Bradview. Cmmunicatins Cmmunicatins channels will be required frm Bradview t Intercnnectin Custmer s facilities that meet r exceed WECC s requirements f redundancy and gegraphic diversity and with sufficient speed t meet the criteria specified abve. Cmmunicatins channels will be required frm Garrisn t Bradview that meet r exceed WECC s requirements f redundancy and gegraphic diversity and with sufficient speed t meet the criteria specified abve. Intercnnectin Custmer may be allwed t utilize NWE cmmunicatins channels t satisfy all r part f the abve criteria. If NWE allws Intercnnectin Custmer access t the NWE cmmunicatins system, a separate O&M agreement will be develped fr the use f these channels and a mnthly/ yearly fee will be assessed fr the use f these channels. Overlad Management Schemes (Thermal) An Overlad Management Scheme (OMS) is required t prtect the 500 kv Series Capacitrs frm ptential verlads that may ccur under certain perating cnditins. Intercnnectin Custmer is t design and wn a timed ut Overlad Management Scheme that will trip Intercnnectin Custmer s Generatr if Intercnnectin Custmer ignres the signal t reduce generatin. NWE will design and install the Facilities within the Bradview 500 kv Substatin. Send alarm and/r runback signal t Intercnnectin Custmer and t the NWE System Operating Cntrl Center (SOCC) when lading n the Bradview series capacitrs exceeds 100%. At the same time that the signal is transmitted t Intercnnectin Custmer, a timing relay is t be initiated that will pen the Intercnnectin Custmer generatr breaker , if the verlad is nt eliminated. 14

15 Cmmunicatins channels will be required frm Bradview t Intercnnectin Custmer and t the NWE System Operating Cntrl Center (SOCC) t transmit alarm and/r runback signals. Supervisry Cntrl and Data Acquisitin Hardin Aut Substatin Remte Terminal Unit (RTU) Upgrade An upgrade is required at Hardin Aut. NWE will design and install the RTU upgrade. Line Breaker Cntrl/Indicatin Switch status is t be prvided fr Breaker PCB 100-XXX t NWE supervisry. NWE will design and install and Intercnnectin Custmer will retain wnership. Analg Quantities 115 kv line A, B and C phase currents, megawatts, megavars, kilvlts, and distance t fault are t be reprted via Mdbus t the RTU. Psitive readings indicate flw frm Hardin Aut. NWE will design and install and Intercnnectin Custmer will retain wnership. Alarms Any perfrmance limiting cnditins fr any f Intercnnectin Custmer s equipment in the Hardin Aut Substatin r assciated with the 115 kv line between the Hardin Aut Substatin and Intercnnectin Custmer s facilities shall be alarmed. NWE will design and install and Intercnnectin Custmer will retain wnership. Tie Pint RTU The Tie Pint RTU shall be lcated at the Hardin Aut Substatin. Generatr Breaker Indicatin 15

16 NWE shall have supervisry cntrl f Intercnnectin Custmer s breaker and switch status nly fr breaker Generatr Analg Quantities frm Tie Pint metering as defined Kwh t NrthWestern Energy Kwh frm NrthWestern Energy Instantaneus megawatts Instantaneus megavars Instantaneus A, B, and C phase kv frm metering PT s. Instantaneus A, B, and C phase amps frm metering CT s. Cntrl Huse Mdules (Type) PCB 100-XXX Set 1 Line Mdule PCB 100-XXX Set 2 Line Mdule Tie Pint RTU Mdule Replace Existing Panels/Mdules The 115 kv Bus Differential will need t be replaced due t wrking space requirements. NWE design and wn the Bus Differential Cubicles Cubicle and Mdule additins will match existing relay panel/mdule cnstructin size and type. 16

17 Miscellaneus Relay Prtective Zne Diagram See One Line Drawing in Appendix A Crdinatin f Relay Settings Prcess NWE will wrk with Intercnnectin Custmer r its cnsultant t crdinate the settings and requirements fr the 115 kv bus differential, 115 kv line backup relaying, breaker failure and generatr backup relaying. 17

18 Intercnnectin Metering Equipment Meter Frm, Vltage, & Class: This prject will require ne Frm 9S, 120 Vlt, billing revenue class watthur meter. Meter Type/Manufacturer: Siemens type 2510 Maxsys multi-functin meter r equivalent. Meter Cmmunicatin Requirements: Telemetered Data: Data frm the meter t the cntrl huse will be transmitted between tw shrt haul mdems using RS232. If fiber is an ptin, it will be the preferred medium. Tw shrt haul Mdems per meter r a fiber link per meter will be required. Shrt haul mdems will be supplied by the cmmunicatin department and shall meet their specificatins. If the shrt haul mdems require external pwer it must be cmpatible with and cnnected t the auxiliary pwer surce f the meter. Data transmissin frm the shrt haul mdem, lcated inside the meter enclsure, t all dwnstream pints will be determined by the cmmunicatin/relay departments f NWE. The RS232 prt n the meter is strictly fr internal NWE use. MODBUS prtcl will be used fr data transmissin n the RS232 prt f the revenue meter. Metered metrics extracted frm the revenue meter are limited t: 18

19 Delivered & Received MWH, Instantaneus ± MW, Instantaneus ± Mvar, Instantaneus Phase A Vlts & Amps, Instantaneus Phase B Vlts & Amps and Instantaneus Phase C Vlts & Amps. Depending upn timing issues the instantaneus amps might nt be included in the telemetered data. Mdem Data: Revenue meter will be equipped with internal dial-up phne mdems. Apprpriate phne cmmunicatin cnductrs will be required t the meter. A dial-up mdem and a MSU (mdem sharing unit) may be required at the cntrl huse. Special Prgramming Requirements: Bi-directinal metering will be required at the billing metering pint. Transfrmer lss cmpensatin will nt be required. Auxiliary Pwer Requirements (Meter Only): DC auxiliary pwer will be required n the revenue meter. If DC is nt available, then AC can be used in cnjunctin with a backup UPS. The UPS will be installed inside the meter enclsure. Meter Lcatin Physical: Distance frm the CT s As clse t the revenue meter as pssible. In the event that the ttal secndary circuit length exceeds fifty feet per phase, greater than # 10 AWG cpper will have t be used. Actual size will be dependant upn the circuit length. 19

20 Distance frm the PT s Same requirements as fr the CT s. Enclsure requirements: The standard NWE s meter enclsure will be used at the meter site. Munting Structure: NWE will design and install a structure that meets the abve requirements n which the meter enclsure will be munted. Intercnnectin Custmer will wn the structure and will be billed accrdingly. Meter Lcatin Electrical: The metering pint will be n the substatin side f breaker 100-XXX at the Hardin Aut Substatin. Meter Cnnectivity: Cabling requirements fr instrument transfrmers: Current Transfrmers: Fur # 10 AWG r larger, cpper cnductrs. Actual size dependant upn verall circuit length. Vltage Transfrmers (PT s): Fur # 10 AWG r larger, cpper cnductrs. Actual size dependant upn verall circuit length. Auxiliary DC Pwer: (Auxiliary pwer fr the revenue meters). Tw # 12 AWG r larger cpper cnductrs. Heater and AC Pwer t the meter enclsure: 20

21 One three-wire 240-vlt circuit f at least # 10 AWG r greater, cpper cnductrs. Cabling requirements fr Telemetered data, mdem, KYZ, EOI & ther Phne Mdem: Tw #24 AWG r larger, twisted pairs - ne pair t be designated as spare Standard Cat 5 cabling wrks well. Shrt haul mdem requirements: Fur #24 AWG r larger, twisted pairs - tw pairs t be designated as spares Standard Cat 5 cabling wrks well. Optinal pulse utput cabling fr KYZ, EOI r ther: IF REQUIRED Sixteen #18 AWG r greater stranded cpper cnductrs - eight t be designated as spares. Cnductrs must have a minimum insulatin rating f at least 120 Vac. Meter Testing: The revenue meter will be fully tested prir t installatin and will be re-certified fr accuracy n an annual basis. The Generatin Owners will be respnsible fr all csts assciated with the annual re-certificatin. A typical re-certificatin meter test, at 2002 levels, wuld cst apprximately $ Instrument Transfrmer Requirements: Vltage Transfrmers (PT s) Manufacturer & Type: Unspecified at this time. The metering PT s shuld be f sufficient rati t supply 120 VAC t the ptential metering circuits inside the watthur meter. At 115 KV this rati calculates t be apprximately 550:1. A 600:1 wuld supply apprximately 110 Vac t the meter and shuld be sufficient. 21

22 A secndary winding dedicated t revenue metering nly. Accuracy class t be at least 0.3 % If 0.15% transfrmers are available they shuld be used. The Burden rating shuld be ZZ with a thermal rating f at least 2 kva. The BIL t be determined by substatin design but will prbably be 550 kv r higher. Current Transfrmers (CT s) Manufacturer & type Unspecified at this time. Current rati: T be f sufficient rati t supply at least 5 amps f secndary current t the metering elements when the generatr is perating at its nrmal capacity. There are a number f crrect chices depending upn the Rating Factr f the chsen CT. The chices listed belw are nt the nly pssibilities but they are mre cmmn and may be built in the higher accuracies f 0.15 % r 0.20%. Higher accuracy shuld dictate the actual rati purchased. If the bank is rated at 120 MVA it equates t 602 Amps, apprpriate ratis wuld be a 500:5 with RF f 2, r a 600:5 with a RF f 1.5 Accuracy class t be at least 0.3 % thru a Burden f 2.0 Ω. During perids f reverse flw, when the plant is receiving pwer frm the grid, the current passing thrugh the current transfrmers will be minimal. It is therefre imperative that the mst accurate instrument transfrmers are emplyed. If 0.15% transfrmers are available they shuld be used. If 0.15% instruments are fund they may be de-rated t a Burden f 1.0 Ω but shuld have a rating f at least 0.3% 5% rated current. The BIL t be determined by substatin design but will prbably be 550 kv r higher. 22

23 Instrument Transfrmer Testing: The current transfrmer and the vltage transfrmers (PT s) will be fully tested at ur metershp prir t installatin. If preferred, NWE can test the instrument transfrmers On Site using NWE s Mbile Metering Lab (MML). The cst fr the MML per hur is $ and des nt include labr r ther equipment. This testing nrmally requires a fur-man crew and a bucket truck. If the instruments transfrmers are nt cnnected and sitting n the grund then testing may nly require a tw man crew and a ladder. All instrument transfrmers will be tested On Site at six-year intervals. The Generatin Owners will be respnsible fr all csts assciated with these tests. Depending upn the amunt f discnnectin and recnnectin, a typical re-certificatin instrument transfrmer test, at 2002 levels, wuld cst apprximately $3, t $5, Further Cnsideratins - Instrument Transfrmer Testing Installatin f bypasses. It may be prudent t design and install peratinal bypasses n all instrument transfrmers. On-Site instrument transfrmer testing using NrthWestern s MML will be required at six year intervals. Prir t testing, all instrument transfrmers must be islated and discnnected frm the circuit with the apprpriate clearances taken. If circuit bypasses are nt installed, shutdwns may be required that culd result in lst revenue. The average shut dwn is apprximately six hurs. If the instrument transfrmers are t be lcated inside NWE s substatin, the design and cnstructin f the circuit bypasses wuld be the respnsibility f NWE but all csts wuld be brn by RMP. Metering Csts: Estimate f the cst t install metering: Metering installatin frm the secndary taps n the instrument transfrmers, t the utput f the shrt haul mdem lcated inside the cntrl huse; the estimated metering cst is $10, This wuld include the meter, enclsure, mdems, cable/wire and labr t install. 23

24 This estimate des nt include the cst f the instrument transfrmers r their installatin. This estimate des nt include installatin f undergrund cnduits and ther related hardware fr the cntrl, secndary, heating, and auxiliary circuits. Metering Installatin Time Table: Order and receipt f the revenue meter: Allw sixteen weeks frm the time NWE places the meter rder with the factry t its arrival at NWE s metershp. Allw tw weeks frm the arrival f the revenue meter at NWE s meter shp t the cmpletin f all necessary meter testing. Metering enclsure: Allw seventeen weeks fr the cnstructin f the metering enclsure. This time is necessary t rder and receive all the necessary cmpnents f the enclsure. Actual cnstructin can be dne in tw wrking days. Mdems, MSU and miscellaneus metering cmmunicatin equipment: Allw eight weeks frm rder date t their receipt. Site preparatin: The installatin f the instrument transfrmers, and all cnduits fr cntrl cables and secndary circuits must be installed prir t the installatin f the meter enclsure and meter. All cntrl cables, fiber (ptinal), heating circuits, auxiliary circuits, and secndary circuits must be prperly installed prir t the installatin f the meter enclsure and meter. Actual meter installatin: After the site preparatin has been cmpleted allw fur wrking days fr meter installatin. Installatin includes munting and wiring the metering enclsure. 24

25 Cnnecting and testing all cntrl, cmmunicatin, heating, auxiliary and secndary circuits. Prgramming and cmmissining the revenue meter, instrument transfrmers and assciated secndary wiring. Ownership & Respnsibilities: NWE will be respnsible fr the purchase and delivery f the instrument transfrmers t the metershp fr testing and then fr their transprtatin t the metering site. If the instrument transfrmers are lcated inside a NWE sub-statin then NrthWestern Energy will install the instrument transfrmers. Intercnnectin Custmer will pay fr the cst f the instrument transfrmers and their installatin. Nthing ther than the billing meter will be cnnected t the secndary windings dedicated t the revenue metering. Intercnnectin Custmer will retain wnership f all instrument transfrmers. NWE will prvide maintenance and testing f all instrument transfrmers. All maintenance and testing t be paid fr by Intercnnectin Custmer NWE will wn, perate, and maintain all metering hardware frm the secndary terminals f the instrument transfrmers. The cst f the metering hardware and its installatin, including but nt limited t the meters, enclsures, cmmunicatin devices, and wiring will be the respnsibility f Intercnnectin Custmer. 25

26 NrthWestern Energy Cst Summary NWE csts n NWE Equipment (Equipment wned by NWE inside Hardin Aut Substatin) NWE Substatin $ 172,800 NWE Relaying $ 99,500 NWE Metering $ 10,000 NWE SOCC EMS Interface $ 15,000 SUBTOTAL $ 297,300 *Tax 15% $ 44,595 TOTAL $ 341,895 * The 15% Tax Surcharge is authrized by the IRS fr mnies paid by December After this date the tax surcharge is subject t change and the IRS apprved rate fr cllectins after December 2004 will be applied. 26

27 NWE csts n Intercnnectin Custmer (Equipment Owned by Intercnnectin Custmer inside NWE Substatins) Hardin Aut Substatin Equipment $ 242,100 Hardin Aut Substatin Relaying $ 21,500 Remedial Actin Scheme $ 215,000 TOTAL $ 478,600 27

28 Appendix Listing Appendix A Substatin Layut Drawings Appendix B Substatin Equipment Appendix C Relaying Csts Appendix D Metering Schematic Appendix E Hardin Aut Substatin Cnstructin Time

29 Appendix A: Substatin Layut Drawings Hardin Aut Substatin One Line Diagram Hardin Aut Substatin Physical Layut 1

30 Appendix B: Substatin Equipment & Csts 2

31 Appendix C: Relaying Csts 3

32 Appendix D: Metering Schematic 4

33 Appendix E: Hardin Aut Substatin Cnstructin Time 5