BC HYDRO REAL TIME OPERATIONS OPERATING ORDER 6T – 29 EMERGENCY MANUAL LOAD SHEDDING and PEAK LOAD REDUCTION PROCEDURES Supersedes 6T-29 issued 10 June 2014 Effective Date: 02 July 2014 Review Year: 2015 APPROVED BY: Denotes Revision Original signed by: ___________________ Paul Choudhury General Manager, Real Time Operations OO 6T-29 Effective Date: 02 July 2014 Page 2 of 13 1.0 GENERAL Certain system conditions require BC Hydro to shed customer load rather than risk an uncontrolled failure of components or cascading outages of the Interconnection. This order specifies procedures to manually shed customer load after all other remedial steps have taken place. It also specifies Peak Load Reduction Procedures and guidelines to trip inter-ties to protect BC Hydro system in severe under frequency situations. Refer to the following BC Hydro operating orders for various load shedding programs which Emergency Manual Load Shedding (EMLS) is considered supplemental to or to be used in conjunction with: Note: OO 6T-25: Operation Plan for Capacity and Energy Emergencies. OO 6T-28: Automatic Under-Frequency Load Shedding program. OO 6T-34: Automatic Under-Voltage Load Shedding program. Load shedding in the Ft Nelson Area is implemented automatically due to Alberta Integrated System conditions or directed by AESO. Refer to 3T-FNC-01 and 7D-FNN-01. Refer to OO 1T-07B for the authority of System Operators to carry out customer firm load shedding. This order complies with NERC Standard EOP-003 Load Shedding Plans. 2.0 RESPONSIBILITIES The Transmission Coordinator (TC) is responsible for assessing the need and has full authority to: Carry out or direct the applicable Grid Operator (GO) to carry out emergency manual load shedding as needed. Carry out or direct the applicable Grid Operator (GO) to off-load interties as needed. Direct the applicable Load Operator (LO) to begin peak load reduction as needed. The Grid Operator (GO) is responsible for: Executing emergency manual load shedding directives from the TC on an emergency priority basis. Executing emergency intertie off-loading directives from the TC on an emergency priority basis. Taking any necessary immediate load shedding action to manage any local area risk. Whenever possible, advise the TC prior to acting. The Load Operator (LO) is responsible for: Executing for the peak load reduction directives by the TC on a priority basis. Taking any necessary immediate load shedding action to manage any local area risk. Whenever possible, advise the TC prior to acting. The System Control Manager (SCM) is responsible for: Assigning the TC to carry out the monthly EMLS exercise as described in Appendix 6 of this operating order. Advising the Manager, Real Time Operations of any required changes to this operating order. The General Manager, Real Time Operations is responsible for: Periodically reviewing the adequacy of the EMLS and Peak Load Reduction procedures with applicable parties. Providing and maintaining facilities, supplemental procedures and personnel training adequate to meet the requirements of this operating order. OO 6T-29 Effective Date: 02 July 2014 Page 3 of 13 3.0 EMERGENCY MANUAL LOAD SHEDDING (EMLS) EMLS is to be used when the Transmission Coordinator judges that the load must be reduced as soon as possible. EMLS might be necessary for a number of conditions including (but not limited to): Insufficient automatic under-frequency load shedding to arrest frequency decay. Insufficient automatic under-voltage load shedding to prevent voltage collapse. Inability to restore or maintain proper generation-load balance due to severe shortages of generating capacity. Inability to increase frequency by adjusting generation alone to permit synchronizing with other areas. System component overloads which cannot be rectified by other means. For EMLS purpose, the BC Hydro integrated system is segmented into four sub-areas: Lower Mainland (LM), Vancouver Island (VI), Northern Interior (NI), and Southern Interior (SI). For each area, EMLS will be done in three approximately equal blocks (1, 2, and 3) with Block 1 being the first shed. The total shedding of blocks 1, 2 and 3 shall equal one half of the estimated peak load for that area. Appendix 1- 4 list all load components to be shed with each block in each area. If practical, shedding should be spread over the system with all areas participating proportionately, but the TC may order the shedding for specific areas of the system when there is a regional generation and load imbalance. The load shedding requirement will generally be recognized and load shedding ordered by the TC. But in the event an area is islanded, the GO / LO responsible for the islanded area shall shed load as necessary to maintain frequency. As a minimum, the TC, GO or LO will take action to avoid sustained operation below 57.9 HZ in order to avoid serious problems for customers or BC Hydro equipment. Using supervisory control provided by BC Hydro Energy Management System (EMS), the operator shall be capable of shedding all three blocks in an area in less than five minutes. Appendix 5 describes the EMS displays to be used for EMLS. The permission to operate devices needed to shed load has been assigned to the TC in addition to the applicable GO and/or LO. The TC does not monitor alarms associated with these devices. A poke point to the EMLS screens can be found on each grid sector overview. Additionally, the Transmission Coordinator Overview has a poke point to the EMLS. System voltage shall be closely monitored and adjusted during load shedding. Manual load shedding should continue until frequency is stabilized and line and equipment loading is within their capability. If residential circuits are shed for more than 30 minutes, the TC or LO should use peak load reduction procedure, if possible, to enable restoration of these residential circuits. The terminology used by the Transmission Coordinator to order Emergency Manual Load Shedding, if necessary, will be: "This is an emergency. Shed Emergency Manual Shedding Block(s) _ _ _ _ _ _ for the _ _ _ _ _ _ _ _ (LM / VI / NI / SI) area immediately.” All verbal communication involving directives to shed load will utilize formal three-part (repeat-back) communication procedures, using English as the working language. OO 6T-29 Effective Date: 02 July 2014 Page 4 of 13 4.0 PEAK LOAD REDUCTION Refer to OO 6T-25 OPERATION PLAN FOR CAPACITY AND ENERGY EMERGENCIES for more details. During the onset of an Energy Emergency, Peak Load Reduction can help avoiding widespread emergency load shedding. A requirement for peak load reduction will generally occur with several hours warning. PSOSE and FortisBC shall, as necessary, initiate Transmission Voltage Customer Emergency Load Curtailments to reduce the system load. Also note that load shaving by voltage reduction may also be used in the distribution system, if available. This procedure requires activation in the field and, therefore, is more suitable for longer term load reduction. 5.0 OPENING OF INTERTIES External Balancing Areas that are seriously under generating can pose a threat to the BC Hydro system. Interties need to be tripped if the BC Hydro system is exporting, the frequency is 1 below 57.9 Hertz and is continuing to decline despite efforts to arrest the decay. In such situation, the Transmission Coordinator will direct the appropriate Grid Operators to off-load any intertie with the US, Alberta, FortisBC or Alcan where the flow of power is out of the BC Hydro system. 1 57.9 Hz as per “WECC Coordinated Off-Nominal Frequency Load Shedding and Restoration Requirements” 6.0 VOLTAGE CONTROL DURING EMERGENCIES Voltage levels must be closely monitored while load is being shed. All reactive resources should be utilized to control voltage. Circuits should be switched out of service as necessary to control if there is an overvoltage condition when the load is dropped. (See OO 7T-22 for Voltage Tolerances) In addition to 500 kV lines, the TC will consider cutting out 230 kV cable circuits to reduce VARs. Lower Mainland cables contribute charging VARs as follows: CCT U/G Length (km) CCT O/H Length (km) Total CCT Length (km) % of CCT U/G % of CCT O/H CCT Cable MVAR (3 ph at 242kV) 230kV CCTs 2L31 2L32 2L33 2L39 2L40 1.1 8.6 8.7 3.3 3.3 0.0 0.0 0.0 21.0 12.4 1.1 8.6 8.7 24.3 15.8 100% 100% 100% 14% 21% 0% 0% 0% 86% 79% 9.2 67.3 78.0 26.7 27.0 2L45 2L50 2L51(COK-BND) 2L51(HPN-BND) 2L53 2L55 2L56 2L62 2L64 6.1 7.4 9.2 7.7 7.3 11.3 2.2 0.8 7.1 0.0 24.2 0.0 0.0 0.0 0.0 32.3 12.6 8.1 6.1 31.6 9.2 7.7 7.3 11.3 34.5 13.4 15.2 100% 23% 100% 100% 100% 100% 6% 6% 47% 0% 77% 0% 0% 0% 0% 94% 94% 53% 36.4 44.8 74.4 62.8 46.9 71.6 13.5 4.7 46.3 CCT OO 6T-29 Effective Date: 02 July 2014 Page 5 of 13 7.0 RESTORATION OF SERVICE The GO and LO shall obtain permission from the TC prior to restoring load that was shed manually or automatically. When the BC Hydro system is tied to BPA, the TC shall notify and consult with the Peak Reliability (PeakRC) Reliability Coordinator (RC) prior to restoring loads shed by under frequency relays, unless there is an automatic load restoration scheme in place. Restoration of TVC load affected by Peak Load Reduction is the responsibility of PSOSE and FortisBC, in consultation with BC Hydro RTO. 8.0 REVISION HISTORY (This order is also posted on BC Hydro’s External website) Revised By TMN Revision Date 4 September 2009 DSM CAP DSM MPP MPP/MH 17 September 2009 09 September 2010 01 October 2010 21 September 2011 09 December 2011 MPP/LR/HQ 13 December 2011 MPP MPP MPP MPP 05 September 2012 19 July 2013 10 June 2014 03 July 2014 Summary of Revision New Operating Order combining 6T-29A, 6T-29B, 6T-29C, 6T-29D and 6T-29E. Revised LM, NI and SI appendices. BCTC changed to BC Hydro. Appendix 3 – EMLS Block 3 - updated. Annual Review Performed. Updated for CYP T3. Additional updates in Appendix 1 and 2 (EFM shutdown). Updated Lower Mainland Block 3, Southern Interior Block 3, remove EFM from Vancouver Island Blocks and minor updates. Annual Review Performed. Annual Review Performed. Annual Review Performed. Updates to Appendix 1, Section 2.0; Appendix 3, Section 3.0; Section 1.0; Appendix 4, Section 1.0 OO 6T-29 Effective Date: 02 July 2014 Page 6 of 13 Appendix 1 EMLS – Lower Mainland Area 1.0 EMERGENCY MANUAL SHEDDING BLOCKS Manual load shedding may require up to 50% of the area load to be shed in 3 blocks within 5 minutes. The shedding described in the table in Section 2 is in order of priority within each block. If under frequency load shedding has occurred, some of the loads may already have been shed. Bold and underlined stations and/or their loads are part of the automatic under-frequency load shedding scheme and might have been tripped should this auto shedding scheme have operated. MW (auto) in the table summarizes the amount of load shed by automatic under frequency load shedding. Voltage should be monitored frequently while load is being shed. At the direction of the TC, circuits should be cut out as necessary to control the voltage. Once load shedding complete, switching should commence to restore station service to affected stations. 2.0 EMERGENCY MANUAL LOAD SHEDDING PROCEDURE Shedding should be carried out using the EMLS_OV screen as shown in Appendix 5 (Figure 1). The real time loading on each element to be shed is shown on the screen. Follow the steps in sequential order as listed in these tables to shed each block: Device EMLS Block 1 at CYP open at WLT open at ALZ open at BND open 60CB5, 60CB9 60CB13 (T2, 60L89) 60CB6, 60CB7 (open one feed to CAP, GLR, HCT, JLN, JRI, NOR, NVR, SWP, VDK) 60CB2, 60CB3 (T1) 60CB5, 60CB6 (N.O.) 60CB14 (T2) 60CB9 (T3) 60CB7, 60CB1 60CB6 (T2) 60CB11, 60CB3 60CB4 (T3) 25CB4,25CB5, 25CB6 (T4/T1) 12CB1, 12CB2 (N.O.), 12CB3, 12CB4 (T1) 12CB5, 12CB6 (N.O.), 12CB7, 12CB8 (T2) Affected Stations MW (man) 25 MW (auto) 0 NXC, SWP, JRI, VDK, DCV, NVR, ERW, NOR, JLN, CAP, GLR, HCT 350 135 CHK, SMW, TMO, ALZ 203 50 BND 131 0 Total Block #1 709 185 HSB, LBY OO 6T-29 Effective Date: 02 July 2014 Page 7 of 13 Device EMLS Block 2 at KI1 open at KI2 open at MAN open at MAN open at SPG open 60CB10, 60CB15 (60L31) 60CB1, 60CB20 (60l32) 2CB4, 2CB5 (2L64) 60CB3, 60CB4 (T1) 60CB6, 60CB7 (T2, 60L43) 60CB9, 60CB10 (T3) (60L46/38) 2CB1, 2CB2 (2L55) 2CB4, 2CB5 (2L53) 2CB3, 2CB6 (2L56) at NEL open at COK open MW (man) MW (auto) KI1, LF1,SEA, RIM, YVR,RSR, GDK, UNS, UNY 234 88 CSN, SPG MAN 236 182 0 93 Total Block #2: 652 181 MW (man) MW (auto) CSQ, DGR, MUR (Vancouver downtown load) 496 130 NEL (distribution load) 190 135 COK (distribution load) 180 176 Total Block #3: 866 441 ALL LM BLOCKS TOTAL 2227 807 2CB1, 2CB6 (2L44) Device EMLS Block 3 at MUR open at CSQ open Affected Stations 2CB1, 2CB9 (2L50) 2CB3, 2CB4 (2L31) 2CB2 (T1) 2CB5, (T2) 2CB6, 2CB7 (T3) 2CB1 (2L20) 12CB3, 12CB35 (T3) 12CB34, 12CB12, 12CB2 (T2) 12CB1 (T1) 25CB41, 25CB42 (T4) 25CB43, 25CB44 (T5) 25CB32, 25CB34 (T3) Affected Stations OO 6T-29 Effective Date: 02 July 2014 Page 8 of 13 Appendix 2 EMLS – Vancouver Island Area 1.0 EMERGENCY MANUAL SHEDDING BLOCKS Manual load shedding may require up to 50% of the area load to be shed in 3 blocks within 5 minutes. The shedding described in the table in Section 2 is in order of priority within each block. If under frequency load shedding has occurred, some of the following loads may have already been shed. Voltages should be monitored frequently while load is being shed. At the direction of the TC, circuits should be cut out as necessary to control the voltage. At the pulp mills, the thermal mechanical pulping (TMP) load is shed. PAL is 30 MW and CFT is 20 MW in block “A”. PAL “B” is the 25 kV residential load. Once load shedding complete, switching should commence to restore station service to affected stations. EMLS Block Load or Station 1 GTP-A PAL-A CFT-A 2 GTP-B PVO 3 PAL-B NFD 120 MW HSY-A HSY-B HSY-C Approximate Total Maximum Block MW CLD-A 292 MW ESQ-A 304MW TOTAL 2.0 716 MW EMERGENCY MANUAL LOAD SHEDDING PROCEDURE The manual load shedding should be performed from the VI Manual Load Shedding screen as shown in Appendix 5 (Figure 2). It is based on the same load shed matrix used by the VI Automatic Under-Voltage Load Shedding scheme. The VI total actual real time load is displayed on this screen at the bottom. The VI load change (shed) can be calculated by comparing the VI load display reading before and after the load shedding. The load shedding screen has 12 non-EMLS blocks and 3 EMLS blocks. The automatic (AUVLS) scheme sheds loads displayed in the non-EMLS blocks 1 to 8. Non-EMLS blocks 9 to 12 are used by the VI Grid Operator to shed load for local system requirements. The blocks are identified by the yellow color border. Each block can be tripped by a single push button that would send trip signal to appropriate breakers at the load locations. OO 6T-29 Effective Date: 02 July 2014 Page 9 of 13 Appendix 3 EMLS – Northern Interior Area 1.0 EMERGENCY MANUAL SHEDDING BLOCKS Manual load shedding may require up to 50% of the area load to be shed in 3 blocks within 5 minutes. The shedding described in the table is in order of priority within each block. If under frequency load shedding has occurred, some of the loads may already have been shed. Voltage should be monitored frequently while load is being shed. At the direction of the TC, circuits should be cut out as necessary to control the voltage. Once load shedding complete, switching should commence to restore station service to affected stations. EMLS Block Station 1 CRD WSN 2.0 Device 60CB3, 18, 11, 13 (Check CRD transfer bus) 60CB2, 3 Affected Stations/Circuits CRD MW Load 160 60L338 (BCM, HCR, FMC- 50%) * 60L310 60L392 Sub Total 60 16 236 SCK RUP 60CB6, 7 60CB10, 15 * Advise FMC to shed all load after EMLS is completed 2 BLW MFE GLN TKW 2CB2, 6 1CB1, 6 1CB2, 3 1CB9, 11 2L307 1L366, 368 1L384 1L396 Sub Total 105 5 23 47 180 3 RBF FHS BVY 25CB11, 13 25CB1, 25CB2 60CB1, 3, 9, 11 KDS 2CB1, 2CB3 RBF (25KV Load) FHS 60L354 (CHF) BVY (25 kV load) 2L319 (MML) + 2L320 (KMI) Sub Total 30 20 26 24 70 170 TOTAL 586 EMERGENCY MANUAL LOAD SHEDDING PROCEDURE Shedding should be carried out using the EMLS OV screen as shown in Appendix 5 (Figure 1). The real time loading on each element to be shed is shown on the screen. Follow the steps in sequential order as listed in the above table to shed each block: OO 6T-29 Effective Date: 02 July 2014 Page 10 of 13 Appendix 4 EMLS – Southern Interior Area 1.0 EMERGENCY MANUAL LOAD SHEDDING BLOCKS Manual load shedding may require up to 50% of the area load to be shed in 3 blocks within 5 minutes. The shedding described in the table is in order of priority within each block. The SI West area peak load approximately 770 MW and the SI East Area peak load is approximately 160 MW. If under frequency load shedding has occurred, some of the loads may already have been shed. Voltage should be monitored frequently while load is being shed. At the direction of the TC, circuits should be cut out as necessary to control the voltage. Once load shedding complete, switching should commence to restore station service to affected stations. EMLS Block 1 Affected Circuits/Stations 1L219 - KWD (28 MW) Device VVW 1CB2, 1CB10 DUG 1CB6 Approx. MW Load 28 (KWD load may be offset by generation. Shedding is only required if KWD is importing) 60L288 – EV1 NTL 60CB15 23 60L287 – CFE ELK 60CB5 5 Total: 56 2 1L55 - HVC/STL/LLD HLD 1CB3, 1CB4 100 1L244 – WBK NIC 1CB15, 1CB16 75 60L284 60L298 60L299 – JOE/SPL/MYE CBK 60CB7, 60CB8 KBY 60CB4 CBK 60CB5, 60CB6 51 Total: 226 3 DUG T1, T3 and T4 25 kV Feeders 110 T1 and T3 25 kV Feeders DUG 25CB1, 2, 4 & 7 BKL 25CB1, 25CB3 BKL VNT T5, T6 25 kV Feeders VNT 25CB6, 5 & 8 55 60L283 - FST/MVL 2.0 CBK 60CB8, 60CB9 KBY 60CB3 TOTAL 66 15 Total: 301 528 EMERGENCY MANUAL LOAD SHEDDING PROCEDURE Shedding should be carried out using the EMLS OV screen as shown in Appendix 5 (Figure 1). The real time loading on each element to be shed is shown on the screen. Follow the steps in sequential order as listed in the above table to shed each block. OO 6T-29 Effective Date: 02 July 2014 Page 11 of 13 Appendix 5 EMLS Screen Displays in EMS Figure 1: EMLS Overview Display (EMLS_OV, SCADA) OO 6T-29 Effective Date: 02 July 2014 Page 12 of 13 Figure 2: VI Manual Load Shedding (LOADSHED_VI, SCADA) OO 6T-29 Effective Date: 02 July 2014 Page 13 of 13 Appendix 6 EMLS Monthly Exercise In order to increase and maintain readiness for an emergency condition in which an emergency manual load shedding routine (as per OO 6T-29) is required, a monthly simulation exercise of the Emergency Manual Load Shedding is required. The simulation will include the selection of the appropriate circuit breakers for tripping and allowance for the time required for the actual trip execution. The Transmission Coordinator shall lead the exercise. He/she may choose to carry out the entire exercise or delegate any portion of the exercise to appropriate Grid Operator(s) by issuing manual load shedding directives. Please record the time (minutes, seconds) required for completion of the simulated shedding of each load block. Request Time Area Initials Time for Block 1 Time for Block 2 Time for Block 3 Report Time LM VI NI SI Transmission Coordinator: ___________________ Date performed: _________________ System Control Manager: _____________________ This exercise is to be completed by the third Sunday of each month. Return completed form to: Asher Steed
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