BC HYDRO REAL TIME OPERATIONS OPERATING ORDER 7T-30A. NORTH COAST INTERCONNECTION: SKEENA BOB QUINN SUBSYSTEM Supersedes OO 7T-30A dated 07 July 2014

Transcription

1 BC HYDRO REAL TIME OPERATIONS OPERATING ORDER 7T-30A NORTH COAST INTERCONNECTION: SKEENA BOB QUINN SUBSYSTEM Supersedes OO 7T-30A dated 07 July 2014 Expiry Year: 2018 APPROVED BY: Original signed by: Paul Choudhury General Manager, Real Time Operations Denotes Revision

2 Page 2 of GENERAL This order describes the operating procedures for the Northwest Transmission Line (NTL) facilities, added to the North Coast transmission area (7T-30 North Coast Interconnection ). This subsystem is an extension of facilities is between Skeena Bob Quinn, and includes the interconnection of IPP generation (Forrest Kerr), and Transmission Voltage Customers (Red Chris Mine). The Northwest Transmission Line (2L102), and customer owned line (2L387) are scheduled to become operational during the month of July Once energized, the bulk transmission system will provide a secure interconnection into the northwest region of the province. This order provides operating procedures for switching, monitoring and responses for operating the subsystem. Variations from these procedures for specific operating conditions will be provided through additional Operating Plans on a case by case basis. Additional Operating Plans are engineered to support outages and short term operating requirements, superseding as necessary requirements in this order. All RAS information, Reliability Must Run generation requirements, and Operating Limits information are contained in Operating Order 7T-30 North Coast Interconnection for implementation in the Transient Stability Application (TSA-PM). The subsystem s facilities include: 2L102 - a km 287 kv transmission line connecting Skeena (SKA) Substation at Terrace with a new substation Bob Quinn (BQN) near Bob Quinn Lake. Forrest Kerr (FKR) IPP generation station, located about 40 km southwest from Bob Quinn (BQN), owned and operated by AltaGas Ltd. (AltaGas). 2L379 - a 38.7 km 287 kv AltaGas owned transmission line connecting FKR to the BQN 287 kv bus. Red Chris Mine (RDC), a transmission voltage customer s copper/gold mine owned by Imperial. 2L374 - a km transmission line BQN to RDC. FKR is the first IPP project to be connected to the subsystem, with an ultimate capacity of 385 MW. The FKR IPP consists of 3 run-of-the-river hydroelectric generation plant sites: Forrest Kerr (FKR) - nine 26.1 MVA units. Volcano Creek (VOL) - two 10 MVA units, 7 km from tap point to FKR and 1.1 km from tap point to VOL. McLymont (MCY) - three MVA units, 10 km from FKR (to be in service late 2015 in the second stage). 2L374 is expected to be completed by the end of July Once completed, RDC will connect 45 MW load to the BCH transmission system. In addition to the 287 kv substation and 2L374, the RDC site features: An entrance circuit breaker with Point-on-wave switching for converter transformer energization to control voltage sag at the POI. Fibre Optic Cable from Bob Quinn to the Mine site with communication channel for transfer tripping and Remedial Action Schemes (RAS)

3 Page 3 of RESPONSIBILITIES Refer to Operating Orders 1T-11A for Operating Responsibility and Operating Authority assignments for the BC Hydro Control Centre (BCHCC). AltaGas responsibilities to contact the BC Hydro Control Centre are outlined in Operating Order 4T- FRK-01 Sections 2 and 10. Red Chris Mines is responsible for informing BC Hydro of substation equipment status. The BCH Control Centre (BCHCC) Operator is responsible for: Updating the status of the BQN and FKR equipment in the Energy Management System (EMS) when notified of changes by the FKR System Operator. Communicating with the FKR Operators prior to energizing or de-energizing 2L379 or 2L102, so joint action can be taken to minimize the system impacts. Communicating and implementing switching instructions. Issuing and tracking Safety Protection Guarantees and Guarantees of Isolation. Notifying customers of expected system conditions and possible special operating requirements prior to any scheduled separation. 3.0 VOLTAGE CONTROL The BQN normal operating voltage range should be between kv. The system nominal voltage is 287 kv. Voltages must be kept below 315 kv except for short times during switching when higher voltages cannot be avoided. Refer to Section 5.0 for impacts of reactor configurations on voltage when switching 2L102. Also refer to Section 4.0 for reactive equipment considerations and cautions. Bob Quinn Auto-var Control Scheme (BQN AVC) (CURRENTLY NOT IN-SERVICE) BQN should be operated with BQN 2RX22 inserted and manually cut it out when the BQN voltage drops to 290 kv and manually insert when voltage rises to 304 kv. Forrest Kerr Automatic Voltage Regulators (FKR AVRs) The FKR AVRs (generator AVRs) will normally be operated in automatic voltage control mode and used to regulate each generator s terminal voltage. Operation in other control modes (e.g. constant power factor control) must be authorized by BC Hydro. The BC Hydro Control Centre will notify AltaGas whenever the FKR generator AVR voltage set points need to be changed to meet system voltage requirements. AltaGas will comply with this operating request to the full extent of the generator control capabilities considering all safety, and electromechanical constraints and normal power factor requirements. The FKR AVRs will normally be set to regulate the BQN bus voltage at 293 kv (102%). 4.0 EQUIPMENT CONSIDERATIONS Bob Quinn Reactors There are three shunt reactors located within the BQN station and there purpose is to help regulate the high voltages expected under light load periods and low power transfers: BQN 2RX231 (35 Mvar switchable reactor) BQN 2RX22 (15 Mvar switchable reactor )

4 Page 4 of 10 BQN 2RX25 (20 Mvar line reactor tied to 2L374) The BQN 2RX231 (35 Mvar) is operated manually due to a large switching voltage change (i.e. a delta V of approximately 19 kv). Caution: All three BQN reactors shall not be normally in service at same time unless 2L374 is in service. This means that BQN 2RX25 should not be in service unless 2L374 is placed in service, and removed from service when the line is switched out (not normally to be used as a bus reactor). In abnormal conditions, such as any of (SKA 2RX1 or SKA 2RX2 or BQN 2CX1) OOS, the above caution is relaxed provided that 2L102 reactive compensation is undercompensated. See 3T-BQN- 01, Section 2.2. BQN 2RX25 is a line reactor (20 Mvar) and is required for 2L379 operation. When BQN 2D25 is open, BQN 2DRX25 must be opened (cut out). BQN 2SA25 is a sacrificial Surge Arrestor (SSA). It is expected the SSA will fail within ~10 Seconds if DTT to RDC fails following a TOV exceeding 1.16pu (when manual switching or protection operates). See 3T-BQN-01 for detailed information on reactor switching procedures. Bob Quinn Series Capacitor (BQN 2CX1) The series capacitor has been installed within the BQN substation and has been designed to provide 35% of the line series reactance of 2L102. The purpose of the series capacitor is for improving the transmission system angular and voltage stability requirements and the ability to transfer more power across the same transmission circuit. BQN 2CX1 is located on the source side of BQN station (i.e. BQN 2L102 terminal) and when inserted the voltage across the series capacitor will increase the voltage seen on the load side of the BQN substation by approximately 2.3 kv. Automatic Insert Enable/Disable feature: There is an automatic insert control feature is provided for each bank and allows all automatic re-insert protections to be enabled or disabled. This includes the automatic control protection which will insert the bank when 2BP2 is opened. Caution: The automatic control function must be disabled prior to performing any switching. When Auto Insert is Enabled, the capacitor bank will be automatically reinserted after a temporary bypass. When Auto Insert is Disabled (or a permanent bypass), there is no automatic re-insertion and the bank can only can be inserted manually, Bob Quinn 4 th Harmonic Filter (BQN 25HF4) System studies identified a parallel resonance condition near the 4th harmonic as seen looking into the BC Hydro system from the Forrest Kerr Substation. The installation of 4th harmonic filter 25HF4 at BQN is to mitigate high and very slow decaying temporary overvoltage on 1L381 and 1L387 which would result if the fourth harmonic parallel resonance condition is excited. 25HF4 consists of tuned reactors connected in series with a grounded shunt capacitor bank. The capacitor bank has a three phase effective rating of 3.6 MVAR at 27.5kV. Protection for 25HF4 includes a SEL multifunction overcurrent relay for detection of major faults and filter unbalance. Bob Quinn Station Service Equipment BQN primary station service is provided by a 10 MVA step down transformer. The transformer high

5 Page 5 of 10 side voltage is rated to 287 kv. Immediate action will need to be taken to correct voltage deviations greater than plus 10% of this nameplate rating. (i.e. 287 x 110% = 315 kv). If the bus voltages cannot be reduced less than the 315 kv value, the transformer should be off loaded by opening BQN 2DT3 to automatically transfer the station service supply to the standby diesel generator. Abnormal System Configurations For SKA 2B11 outages requirements: Option 1: Open SKA 2CB7, to drop 2L102 under a SKA T2 contingency Option 2: Offload SKA T4 in order to prevent 2L102 power flow through transformer under SKA T2 contingency. However, as a result of this contingency, 2L102 will be open ended at SKA and the line will need to be dropped as the IPP FKR is not design to operate islanded. 5.0 GUIDELINES FOR ENERGIZING CIRCUITS Normal Energization Procedures The following procedures are intended to minimize open-end voltages. With all reactors available no voltages above 315 kv should be encountered except in abnormal situations. During switching, voltages up to 325 kv may be tolerated for no more than two minutes providing a stable voltage no greater than 315 kv will result post switching. This is due the fact that the BQN 2SA25 sacrificial surge arrestor will be placed at risk of failure during prolonged periods with voltage greater than 315 kv. At a voltage of 333 kv, BQN 2SA25 is expected to fail after approximately 10 seconds. The BQN should be operated in accordance with requirements in Section 3.0 during energization procedures. SKA is the lead end terminal to BQN and similarly BQN will the lead terminal to FKR. Under NO circumstances will 2L379 be allowed to be energized from FKR to BQN. Energizing 2L102 2L102 is to be energized from SKA end only. There should be no high voltage issue when all of the reactors are BQN are available (BQN 2RX231, 2RX22 and 2RX25). The SKA 500KV bus voltage should be between KV prior to line energization. The expected open-end voltage on 2L102 will be approximately kV at BQN. Normal pre-switching conditions for re-energizing 2L102 include: The SKA Auto-var control scheme is ON SKA 2CB7: open (SKA 287 Ring OPENED ) SKA 2CB8: open (2L102 OPEN) SKA 2RX1: cut in SKA 2RX2: cut in SKA 2D22: closed BQN 2D23: closed BQN 2RX231: cut in BQN 2BP2: open BQN 2D31: closed BQN 2D32: closed BQN 2CBCX1: closed (Series Capacitor by-passed) BQN 2CB1: open BQN 2CB2: open BQN 2CB3: open BQN 2CB4: open BQN 2CB22: closed BQN 2DT3: closed

6 Page 6 of 10 BQN 2D21: open (2L379 disconnected to FKR) BQN 2D25: open (2L374 disconnected to RDC) Switching Sequence SKA 2CB8: CLOSE Open-end voltage at BQN should be about 305KV (Energizes SKA 2B7, 2RX1/2NRX1, 2RX2/2NRX2, 2L102, BQN 2B3, And 2RX231) SKA 2CB7: CLOSE closing the SKA 287KV bus ring BQN 2CB3: CLOSE BQN 287KV bus voltage will drop to around 298KV (Energizes BQN 2B2, 2RX22 and station service)

7 Page 7 of 10 Energizing of 2L102 for Different Reactor (RX) Configurations When energizing 2L102, and there are reactor outages at SKA and/or BQN, the following preenergization reactor configurations should be observed to protect against high voltage at BQN. The configuration requirements are a function of the pre-switching SKA voltage. The voltage at SKA is controlled in part by the transfers from KIT to MIN (2L103). Table: Expected voltage at BQN and SKA vs RX in-service configuration. With SKA AVC in-service, SKA 500kV bus Voltage: or lower SKA 287kV bus Voltage: or lower: SKA 2RX1 SKA 2RX2 BQN 2RX231 BQN 2RX22 BQN 287kV Bus Voltage SKA 500kV Bus Voltage Energizing 2L379 2L379 can only be energized from the BQN end. The line energizing procedures are outline in FKR local ordering order 4T-FKR-01 under Section 7.1. The following procedure assumes 2L102 and 2L374 are in service. Normal pre-switching conditions for re-energizing 2L379 include: SKA Auto-var control scheme is ON SKA 2CB7: closed (SKA 287 Ring OPENED ) SKA 2CB8: closed SKA 2RX1: cut in SKA 2RX2: cut in SKA 2D22: closed BQN 2D23: closed BQN 2RX231: cut in BQN 2BP2: open BQN 2D31: closed

8 Page 8 of 10 BQN 2D32: closed BQN 2CBC1: open (Series Capacitor inserted) BQN 2CB1: open BQN 2CB2: open BQN 2CB3: closed BQN 2CB4: open BQN 2CB22: closed (BQN 2RX22 cut in) BQN 2DT3: closed BQN 2D21: closed (2L379 connected to FKR) FKR 2CB1: open FKR 2CB4: open Switching Sequence: BQN 2CB2: CLOSE Open-end voltage at FKR should be about 304.5KV (Energizes 2L379) AltaGas permission given to close FKR 2CB1 : CLOSE energize FKR transformer (FKR 2T1) FKR 2CB4 : CLOSE energize FKR transformer (FKR 2T3) Energizing 2L374 2L374 can only be energized from the BQN end. The line energizing procedures are outline in RDC local ordering order 3T-RDC-01 under Section 7.1. The following procedure assumes 2L102 and 2L379 are in service. Normal pre-switching conditions for re-energizing 2L374 include: SKA Auto-var control scheme is ON BQN 2CBCX1: open (Series Capacitor inserted) BQN 2RX231: Cut in BQN 2RX22: Cut in 2L379: Energized (FKR online with a minimum of 15 MVA) BQN 2D25: closed BQN 2DRX25:closed (BQN 2RX25 cut in) BQN 2CB1: open BQN 2CB4: open Switching: BQN 2CB4: CLOSE Open-end voltage at RDC should be about 311KV (Energizes 2L374) BQN 2CB1: CLOSE to close BQN 287 kv bus ring Energizing of 2L374 when BQN 2RX231 is Out Of Service (OOS) and FKR is Offline This section is to be developed.

9 Page 9 of GUIDELINES FOR DE-ENERGIZING CIRCUITS De-Energizing 2L102 Regardless of the DTT status, when manually de-energizing 2L102, best practice is to: offload and open 2L374 to RDC offload and open 2L379 to FKR SKA 2CB8: OPEN (Opening 287 kv SKA Ring) SKA 2CB7: OPEN (Dropping 2L102 to BQN) De-Energizing 2L374 The line de-energizing procedures are outline in RDC local ordering order 3T-RDC-01 under Section 6.1. Open at RDC first then de-energize line from BQN. De-Energizing 2L379 The line de-energizing procedures are outline in FKR local ordering order 4T-FKR-01 under Section 6.1. Open at FKR first then de-energize line from BQN. 7.0 EMERGENCY LINE ENERGIZING REQUIREMENTS Energizing 2L102 To be energized from SKA end ONLY, and there MUST be at least 35 MVAR shunt reactance available at BQN to be switched in PRIOR to picking up the line. 8.0 PROTECTION REQUIREMENTS AND SPECIAL FEATURES Special Requirements For three phase tripping, unsuccessful single-pole-reclose, detection of 2L102 open terminal and receipt of trip signals from 2RX231 and 2CX1 protections, the 2L102 protections will trip into BQN 2L379 protections to trip BQN 2CB1 and BQN 2CB2, and key a DTT to FKR generation. This requirement is necessary to avoid temporary over-voltages for BC Hydro customers, if BQN becomes isolated from SKA. When additional load/generation is connected to the BQN station, these devices 87L/87LS will extend this tripping to include those loads and generation. BQN will receive a non-reclosable DTT from SKA for events including: terminal breaker failure, detection of system over-voltage line connected shunt reactor protection operation. SKA will send BQN a sustained DTT to allow the shunt reactors time for auto isolation. BQN Devices 87L/87LS will block close 2CB1/2CB3 until the received DTT resets. Single Pole Reclosing 2L102 and 2L379 are capable for single pole operation. 2L102 will be operated with reclosing in Position 4 (Trip/Reclose for SLG trips only) at SKA and BQN ends. SKA is designated the lead end. 2L379 will be operated with reclosing in Position 1 (3 pole trip for all faults). BQN is the lead end.

10 Page 10 of 10 Fault Location Acquisition Recorder (FLAR) A FLAR system has been installed to provide fault location data for both 2L102 to SKA (FLAR1) and for 2L379 to Forest Kerr IPP (FLAR2). The communication link to FVO will be an IP based link to the FVOBCTFLAR1 server at FVO. The 3 phase reactor 2LRX23 is installed to block fault wavefronts from the bus side reaching FLAR1. FLAR2 will detect fault wavefronts on the bus side of 2LRX23. FLAR1 and FLAR2 are expected to be part of a development to implement fast bypass switching of the series capacitor 2SC l REVISION HISTORY Revised By Revision Date Summary of Revision SJC,DSM, 7 July 2014 New Order RAC SJC 14 July 2014 Section 3.0 : BQN Auto Var scheme not in service