Voltage and Reactive Procedures CMP-VAR-01

Transcription

1 Voltage and Reactive Procedures CMP-VAR-01 NERC Standards: VAR VAR b Effective Date: 07/31/2012 Document Information Current Revision 2.0 Review Cycle Annual Subject to External Audit? Yes Prepared By Chris Bradley Big Rivers Corporate Approvals Approval - Supervisor Chris Bradley Yes Approval - Vice President David Crockett 07/31/2012

2 Revision Information Revisio Date Notes Revised By n Rev /06/2011 New Document; Replaces PL-VAR-1 Chris Bradley Rev /26/2012 Annual Review; Updated to VAR Chris Bradley Related Documents Notes Source History CMP-VAR-01; CMP-VAR-01.doc; current Revision 2.0 dated 07/31/2012; previous Revision 1.0 dated 09/08/2011; original Revision 1.0 PL-VAR-1 Voltage Reactive Control dated 7/27/07; Document Approval Checklist 1. Request AVR logs from generating plants 2. Check for any changes to step-up transformer tap settings 3. Request verification from plants as to whether generating units have power system stabilizers or not 4. Send procedure via Laserfiche to System Supervisors for verification they have read and understood it 5. Replace old version in Energy Control Manual at HQ and BUCC with newest version and update index 6. Update document index and matrix 7. Provide to Production for distribution to generating plants 8. Provide to HMP&L 9. Post to MISO OASIS

3 Table of Contents Introduction... 1 VAR VAR-001 R VAR-001 R VAR-001 R VAR-001 R VAR-001 R VAR-001 R VAR-001 R7 & R VAR-001 R VAR-001 R VAR-001 R VAR-001 R VAR VAR-002 R VAR-002 R VAR-002 R VAR-002 R VAR-002 R Appendix A: SME List

4 Introduction Big Rivers relies on generating units, capacitors, and transformer load tap changers to regulate system voltages. It is Big Rivers intent to maintain reactive reserves sufficient to provide proper voltages and to self-provide all Mvars within its local balancing area (including Big Rivers owned interconnection facilities) under normal and contingency conditions. System Supervisors shall operate or direct the operation of capacitive and inductive resources within its area including reactive generation scheduling, capacitor switching, transmission reconfiguration, and load shedding. System Supervisors shall direct corrective actions, including load shedding, in order to prevent voltage collapse when reactive resources are insufficient. The status of all reactive elements is monitored by Big Rivers through the EMS system. Transformer taps and capacitors are controlled directly by Big Rivers through the EMS. Direction regarding generator voltage changes is given through phone calls from Big Rivers System Supervisors to each non-exempt generating plant within the Big Rivers balancing area. Big Rivers has sufficient reactive reserves to maintain proper voltages and to self-provide all Mvars within its local balancing area (including Big Rivers owned interconnection facilities) under normal and contingency conditions. To ensure sufficient reactive reserves are available, a current-day and day-ahead analysis is performed. This analysis consists of completing a fill-in-the-blank spreadsheet including all the available reactive resources and load requirements. A dynamic reactive reserve display is also available on the EMS. The use of the on-line power flow model which simulates line, transformer, and generator outages is also used to ensure proper system voltages can be maintained under various normal and contingency conditions. In addition, Big Rivers will follow any voltage level or Var related directives issue by MISO. Legend: Responsibility Planning Responsibility Energy Services Responsibility Engineering Responsibility Transmission Responsibility Production Responsibility VAR Requirement 1: Planning R1. Each Transmission Operator, individually and jointly with other Transmission Operators, shall ensure that formal policies and procedures are developed, maintained, and implemented for monitoring and controlling voltage levels and Mvar flows within their individual areas and with the areas of neighboring Transmission Operators. The intent of CMP-VAR-01 is to formally document Big Rivers policies and procedures related to the monitoring and controlling of voltage levels and Mvar flows within the Big Rivers balancing area and with neighboring regions. This document is reviewed/updated once per calendar year. Additional updates will be completed as necessary. This document is provided to the Big Rivers Plant operations staff and Henderson Municipal Power & Light (HMP&L). All versions of this document and related communications will be maintained for a minimum of three years. An up-to-date hard copy of CMP-VAR-01 is kept in the Energy Control manual for System Supervisor use and reference of monitoring and controlling voltage levels and Mvar flows. It is replaced as changes are made. The Big Rivers document titled CMP-FAC-1 addresses connection requirements including voltage and reactive issues and coordination throughout the document (primarily in R2.1.3 and R2.1.9). In addition, the Big Rivers document titled PL-FAC-1 Transmission Planning Criteria and Guidelines addresses transmission study coordination and communication. Big Rivers has also included terms related to reactive power and voltage regulation in the updated Interconnection Agreement with Kentucky Utilities (KU Interconnection Agreement: Section 9 Page 5 & Section 5 Page 4). 1

5 As a fully integrated Midwest ISO member, Big Rivers is party to the formal policies and procedures developed by the Midwest ISO. The specific Var/voltage related MISO support and duties (including real-time and day-ahead analyses) are described in BPM-018-r4 Voltage and Reactive power Management. The following Midwest ISO documents discuss or address additional Midwest ISO procedures related to reactive resources and/or system voltages: Transmission Emergencies: RTO-EOP-004-r9 Control Status Management: RTO-OP-025-r1 Reactive Supply and Voltage Control Service: BPM-016-r2 Notification of Neighboring Reliability Coordinators Procedure RTO-RA-OP-008-r4 Requirement 2: R2. Each Transmission Operator shall acquire sufficient reactive resources which may include, but is not limited to, reactive generation scheduling; transmission line and reactive resource switching;, and controllable load within its area to protect the voltage levels under normal and Contingency conditions. This includes the Transmission Operator s share of the reactive requirements of interconnecting transmission circuits.. Big Rivers has sufficient reactive reserves to maintain proper voltages and to self-provide all Mvars within its local balancing area (including Big Rivers owned interconnection facilities) under normal and contingency conditions. To ensure sufficient reactive reserves are available, a current-day analysis is performed. This analysis consists of completing a fill-in-the-blank spreadsheet including all the available reactive resources and load requirements. A dynamic reactive reserve display is also available on the EMS. The use of the on-line power flow model which simulates line, transformer, and generator outages is also used to ensure proper system voltages can be maintained under various normal and contingency conditions. In addition, Big Rivers will follow any voltage level or Var related directives issue by MISO. MISO support and duties (including real-time and day-ahead analyses) are described in BPM-018-r4 Voltage and Reactive power Management. Requirement 3: Planning R3. The Transmission Operator shall specify criteria that exempts generators from compliance with the requirements defined in Requirement 4, and Requirement 6.1. Generating units with a nameplate rating of less than 75 MVA are exempt from the requirements in this document. R3.1. Each Transmission Operator shall maintain a list of generators in its area that are exempt from following a voltage or Reactive Power schedule. Exempt units include: Reid 1 and Reid CT. The table below lists the exempt units and their nameplate ratings. Generator Net MVA Reid 1 65 Reid CT 65 2

6 R3.2. For each generator that is on this exemption list, the Transmission Operator shall notify the associated Generator Owner. Big Rivers Electric is both the Transmission Operator and Generator Owner. Therefore, notification is not necessary for this requirement. Requirement 4: Planning R4. Each Transmission Operator shall specify a voltage or Reactive Power schedule at the interconnection between the generator facility and the Transmission Owner's facilities to be maintained by each generator. The Transmission Operator shall provide the voltage or Reactive Power schedule to the associated Generator Operator and direct the Generator Operator to comply with the schedule in automatic voltage control mode (AVR in service and controlling voltage). Big Rivers has the responsibility to specify a voltage or reactive schedule that must be maintained by each synchronous generator at its specified connection bus. In this role, Big Rivers will directly communicate with the generating plant operator and issue direction regarding voltage at each generating unit. At a minimum, Big Rivers will contact plant operators once per day to verify voltages. In general, the following switchyard voltages are to be maintained. However, Big Rivers will provide more specific direction to the plant operators via phone communication as needed. The following are the acceptable voltage ranges. Power flow studies with 2011 summer peak loads were performed to verify no significant transmission problems (voltage collapse, cascading outages, IROL violations, etc) are expected with these levels. Operation outside of these ranges is reportable for compliance purposes unless such operation was approved by Big Rivers system supervisors or MISO. Approval will be granted if all available Var resources are dispatched (generators producing maximum Vars) and the required notification is received and documented. Plant Bus Voltage Range Coleman Coleman Swyd to kv Wilson Wilson EHV to kv Reid Reid 69 Swyd to 72.0 kv HMP&L Station Two Reid 161 Swyd to kv Green Reid 161 Swyd to kv While the above described ranges are acceptable, the voltage ranges below represent the normal voltages maintained at each switchyard. Each plant is expected to maintain voltages within these ranges if possible. Maintaining voltages within this range may be difficult in the short-term (less than 1 hour) due to changing system conditions (potline drop, transmission outages, generation outage, etc.). Therefore, the above described voltage ranges are deemed acceptable and are monitored for compliance purposes. Plant Bus Voltage Range Coleman Coleman Swyd to kv Wilson Wilson EHV to kv Reid Reid 69 Swyd to 72.0 kv HMP&L Station Two Reid 161 Swyd to167.0 kv Green Reid 161 Swyd to kv Plant operations staff shall operate each generator connected to the interconnected transmission system in the automatic voltage control mode unless directed otherwise by Big Rivers System 3

7 Supervisors or MISO. Any deviations from the requirement require notification be made to Big Rivers System Supervisors and should be logged by the generator operator. In no case shall any generating unit be operated in such a manner as to counteract the effect of other voltage regulating equipment on the transmission system by lowering the system voltage or consuming reactive power unless approved or directed by Big Rivers System Supervisors or MISO. Plant operations staff shall provide historical voltage data for each generator and switchyard in electronic format within a 30-business day time frame if required by NERC. Big Rivers is responsible for reviewing the data for compliance with the voltage criteria. Big Rivers is also responsible for documenting the reason or cause for any criteria deviations approved or directed by Big Rivers. Plant operations staff shall be prepared to explain any criteria deviations not approved or directed by Big Rivers. At this time, Plant operations staff has demonstrated that the required data is captured electronically and can be provided in a timely manner. Requirement 5: Planning R5. Each Purchasing-Selling Entity and Load Serving Entity shall arrange for (self-provide or purchase) reactive resources which may include, but is not limited to, reactive generation scheduling; transmission line and reactive resource switching;, and controllable load to satisfy its reactive requirements identified by its Transmission Service Provider. Reactive resources requirements for transmission purchases impacting Big Rivers are in accordance with the Midwest ISO OATT, policies, and procedures and any applicable Big Rivers tariff. It is expected that each PSE and LSE shall arrange for (self-provide or purchase) reactive resources to satisfy its reactive requirements as identified by Big Rivers or the Big Rivers TSP (Midwest ISO). The acceptable and appropriate reactive resources will be determined on a case-by-case basis and may include reactive generation scheduling, transmission line and reactive resource switching, and controllable load. Requirement 6: R6. The Transmission Operator shall know the status of all transmission Reactive Power resources, including the status of voltage regulators and power system stabilizers. Big Rivers System Supervisors can monitor generator and trasmission voltages realtime via the EMS. The status and MVar output of each generator and most capacitors is also available to System Supervisors via the EMS. Plant operations staff shall notify Big Rivers (within 30 minutes) of a status or capability change on any generator real or reactive power resource or any other reactive power resource and the expected duration of the change in status or capability. This includes the status of each automatic voltage regulator and power system stabilizers should they be added to any generating unit. R6.1. When notified of the loss of an automatic voltage regulator control, the Transmission Operator shall direct the Generator Operator to maintain or change either its voltage schedule or its Reactive Power schedule. When notified of the loss of an automatic voltage regulator control, Big Rivers System Supervisors shall direct the generating plant operator to maintain or change its voltage schedule or its Reactive Power schedule. Generator AVR Equipment 4

8 Each plant shall operate with the AVR in service. The operator shall notify Energy Control by phone each time it is necessary to operate its AVR in manual. Plant Operators and System Supervisors will enter the phone call in its operator log. This log will serve as the approval documentation. Plant operations staff shall call Energy Control when manual voltage control mode operation is necessary. During any AVR outage, Energy Control will pay close attention to the voltage levels and will provide direction to the plant operator as necessary. In addition, Plant operations staff will maintain 12 rolling months of operating data for each unit concerning: a. Number of hours each synchronous generator did not operate in automatic voltage control mode; and b. Report containing date, duration, and reason for each period when the unit was not operated in automatic voltage control mode. This data will be made available internally and to SERC and NERC upon request within five business days. Requirement 7 & 8: R7. The Transmission Operator shall be able to operate or direct the operation of devices necessary to regulate transmission voltage and reactive flow. R8. Each Transmission Operator shall operate or direct the operation of capacitive and inductive reactive resources within its area which may include, but is not limited to, reactive generation scheduling; transmission line and reactive resource switching; controllable load; and, if necessary, load shedding to maintain system and Interconnection voltages within established limits. Big Rivers relies on generating units, capacitors, and transformer load tap changers to regulate system voltages. System Supervisors shall operate or direct the operation of capacitive and inductive resources within its area including reactive generation scheduling, transmission reconfiguration, and load shedding. Transformer taps and capacitors are controlled directly by Energy Control through the EMS. Instruction regarding generator voltage changes is given through phone calls from Big Rivers System Supervisors to each non-exempt generating plant within the Big Rivers balancing area. It is expected that any controllable load that may be added in the future will be operated at the instruction of System Supervisors such that system and interconnection voltages will be maintained within established limits. Requirement 9: R9. Each Transmission Operator shall maintain reactive resources which may include, but is not limited to, reactive generation scheduling; transmission line and reactive resource switching;, and controllable load to support its voltage under first Contingency conditions.. R9.1. Each Transmission Operator shall disperse and locate the reactive resources so that the resources can be applied effectively and quickly when Contingencies occur. BREC has kv and 2-69 kv switched shunt capacitor banks located at various substations and plant switchyards throughout their system. The location of each capacitor bank can be seen on the Big Rivers switching diagrams attached as follows: pdf, pdf, and pdf. These resources can be quickly controlled by the System Supervisors via the EMS or the dispatch of field personnel. 5

9 Requirement 10: R10. Each Transmission Operator shall correct IROL or SOL violations resulting from reactive resource deficiencies (IROL violations must be corrected within 30 minutes) and complete the required IROL or SOL violation reporting. Big Rivers shall correct any IROL violations that are a result of reactive resource deficiencies in 30 minutes or less and promptly complete the reporting requirements. SOL violations will also be alleviated as soon as possible. All actions taken with regard to IROL and SOL violations will be done in accordance with all SERC and NERC standards and MISO SOL/IROL policies and procedures. Preventing and Returning from SOLs Procedure RTO-RA-OP-001-r14 Methodology for Identification and Implementation of IROLs and SOLs Procedure RTO-RA-OP- 003-r6 Requirement 11: Planning R11. After consultation with the Generator Owner regarding necessary step-up transformer tap changes, the Transmission Operator shall provide documentation to the Generator Owner specifying the required tap changes, a timeframe for making the changes, and technical justification for these changes. Big Rivers Energy Transmission and Substation Department (ET&S) performs the testing and maintenance of the generating unit step-up and auxiliary transformers. Upon request by Bir Rivers enegineering personnel (coordinated effort between Plant operations staff and transmission operations/engineering staff), ET&S will also implement tap setting changes required for these transformers. Consequently, ET&S will review/update the transformer data (including tap settings, available tap ranges, impedance data, and the +/- voltage range with step-change in % for load-tap changing transformers) at least once per year (and within 30 days of a request). Changes throughout the year shall be reported to Big Rivers Manager of Engineering and at the time the change is made. Additionally, any errors or discrepancies that may be found by the Plant operations staff shall be reported to Big Rivers Manager of Engineering and. If tap changes are required, the following tap change procedure will be followed: 1. Plant operations staff will be notified of the change including the reason for the change and any supporting data or studies. Coordination with HMP&L will be necessary for any changes involving Station Two. 2. When determining the schedule for implementing the tap change, both generating unit outage schedules and transmission reliability concerns will be considered. 3. Plant operations staff shall notify Big Rivers and provide technical justification if it cannot meet the specifications set forth by Big Rivers. 4. When the review is complete, ET&S will be instructed to make the appropriate tap change according to the mutually agreed upon schedule. ET&S will notify Big Rivers Manager of Engineering and when the change is complete. Big Rivers will then update the transformer records and ensure HMP&L is aware of the change (if it involves Station Two). Requirement 12: R12. The Transmission Operator shall direct corrective action, including load reduction, necessary to prevent voltage collapse when reactive resources are insufficient. System Supervisors shall direct corrective action, including load shedding or other load reduction, in order to prevent voltage collapse when reactive resources are insufficient. The status of all reactive elements is monitored by Big Rivers through the EMS system. 6

10 VAR b Requirement 1: R1. The Generator Operator shall operate each generator connected to the interconnected transmission system in the automatic voltage control mode (automatic voltage regulator in service and controlling voltage) unless the Generator Operator has notified the Transmission Operator. Each plant shall operate with the AVR in service. The operator shall notify Big Rivers System Supervisors by phone each time it is necessary to operate its AVR in manual. Plant operators and System Supervisors will enter the phone call in its operator log. This log will serve as the approval documentation. Plant operations staff shall call Big Rivers when manual voltage control mode operation is necessary. During any AVR outage, Big Rivers will pay close attention to the voltage levels and will provide instructions to the plant operator as necessary. Requirement 2: R2. Unless exempted by the Transmission Operator, each Generator Operator shall maintain the generator voltage or Reactive Power output (within applicable Facility Ratings) as directed by the Transmission Operator. R2.1. When a generator s automatic voltage regulator is out of service, the Generator Operator shall use an alternative method to control the generator voltage and reactive output to meet the voltage or Reactive Power schedule directed by the Transmission Operator. R2.2. When directed to modify voltage, the Generator Operator shall comply or provide an explaination of why the schedule cannot be met. Energy Control has the responsibility to specify a voltage or reactive schedule that must be maintained by each synchronous generator at its specified connection bus. In this role, Energy Control will communicate with the generating plant operator and issue directions regarding voltage at each generating unit. At a minimum, Big Rivers will contact plant operators once per day to verify voltages. In general, the following switchyard voltages are to be maintained. However, Big Rivers will provide more specific direction to the plant operators via phone communication as needed. The following are the acceptable voltage ranges. Power flow studies with 2011 summer peak loads were performed to verify no significant transmission problems (voltage collapse, cascading outages, IROL violations, etc) are expected with these levels. Operation outside of these ranges is reportable for compliance purposes unless such operation was approved by Big Rivers system supervisors or MISO. Approval will be granted if all available Var resources are dispatched (generators producing maximum Vars) and the required notification is received and documented. Plant Bus Voltage Range Coleman Coleman Swyd to kv Wilson Wilson EHV to kv Reid Reid 69 Swyd to 72.0 kv HMP&L Station Two Reid 161 Swyd to169.0 kv Green Reid 161 Swyd to kv 7

11 While the above described ranges are acceptable, the voltage ranges below represent the normal voltages maintained at each switchyard. Each plant is expected to maintain voltages within these ranges if possible. Maintaining voltages within this range may be difficult in the short-term (less than 1 hour) due to changing system conditions (potline drop, transmission outages, generation outage, etc.). Therefore, the above described voltage ranges are deemed acceptable and are monitored for compliance purposes. Plant Bus Voltage Range Coleman Coleman Swyd to kv Wilson Wilson EHV to kv Reid Reid 69 Swyd to 72.0 kv HMP&L Station Two Reid 161 Swyd to167.0 kv Green Reid 161 Swyd to kv Plant operations staff shall operate each generator connected to the interconnected transmission system in the automatic voltage control mode unless instructed otherwise by Big Rivers System Supervisors or MISO. Any deviations from the requirement require notification be made to System Supervisors and should be logged by the generator operator. Plant operations staff shall notify Energy Control (within 30 minutes) of a status or capability change on any generator real or reactive power resource or any other reactive power resource and the expected duration of the change in status or capability. This includes the status of each automatic voltage regulator and power system stabilizers should they be added to any generating unit. When notified of the loss of an automatic voltage regulator control, Big Rivers System Supervisors shall instuct the generating plant operator to maintain or change its voltage schedule or its Reactive Power schedule. In no case shall any generating unit be operated in such a manner as to counteract the effect of other voltage regulating equipment on the transmission system by lowering the system voltage or consuming reactive power unless approved or directed by Big Rivers System Supervisors or MISO. Requirement 3: Production R3. Each Generator Operator shall notify its associated Transmission Operator as soon as practical, but within 30 minutes of any of the following: R3.1. A status or capability change on any generator Reactive Power resource, including the status of each automatic voltage regulator and power system stabilizer and the expected duration of the change in status or capability. R3.2. A status or capability change on any other Reactive Power resources under the Generator Operator s control and the expected duration of the change in status or capability. Plant operations staff shall notify Big Rivers (within 30 minutes) of a status or capability change on any generator real or reactive power resource or any other reactive power resource and the expected duration of the change in status or capability. This includes the status of each automatic voltage regulator and power system stabilizers should they be added to any generating unit. 8

12 Requirement 4: Transmission R4. The Generator Owner shall provide the following to its associated Transmission Operator and Transmission Planner within 30 calendar days of a request. R4.1. For generator step-up transformers and auxiliary transformers with primary voltages equal to or greater than the generator terminal voltage: R Tap settings. R Available fixed tap ranges. R Impedance data. R The +/- voltage range with step-change in % for load-tap changing transformers. Big Rivers Energy Transmission and Substation Department (ET&S) performs the testing and maintenance of the generating unit step-up and auxiliary transformers. Upon request by Plant operations staff, ET&S will also implement tap setting changes required for these transformers. Consequently, ET&S will review/update the transformer data (including tap settings, available tap ranges, impedance data, and the +/- voltage range with step-change in % for load-tap changing transformers) generally once per year (within 30 days of a request). Requirement 5: Transmission/Production R5. After consultation with the Transmission Operator regarding necessary step-up transformer tap changes, the Generator Owner shall ensure that transformer tap positions are changed according to the specifications provided by the Transmission Operator, unless such action would violate safety, an equipment rating, a regulatory requirement, or a statutory requirement. R5.1. If the Generator Operator can t comply with the Transmission Operator s specifications, the Generator Operator shall notify the Transmission Operator and shall provide the technical justification. Big Rivers Energy Transmission and Substation Department (ET&S) performs the testing and maintenance of the generating unit step-up and auxiliary transformers. Upon request (generally a coordinated request from Plant operations staff and transmission/engineering staff), ET&S will also implement tap setting changes required for these transformers. Consequently, ET&S will review/update the transformer data (including tap settings, available tap ranges, impedance data, and the +/- voltage range with step-change in % for load-tap changing transformers) at least once per year (and within 30 days of a request). Changes throughout the year shall be reported to Big Rivers Manager of Engineering and at the time the change is made. Additionally, any errors or discrepancies that may be found by the Plant operations staff shall be reported to Big Rivers Manager of Engineering and. If tap changes are required, the following tap change procedure will be followed: 1. Plant operations staff will be notified of the change including the reason for the change and any supporting data or studies. Coordination with HMP&L will be necessary for any changes involving Station Two. 2. When determining the schedule for implementing the tap change, both generating unit outage schedules and transmission reliability concerns will be considered. 3. Plant operations staff shall notify Big Rivers and provide technical justification if it cannot meet the specifications set forth by Big Rivers. 4. When the review is complete, ET&S will be instructed to make the appropriate tap change according to the mutually agreed upon schedule. ET&S will notify Big Rivers Manager of Engineering and when the change is complete. Big Rivers will then update the transformer records and ensure HMP&L is aware of the change (if it involves Station Two). 9

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14 Appendix A: SME List SME Name Title Requirements Robert Thomasson Energy Control Supervisor VAR-001 R2, 6, 7, 8, 9, 10, 12 Chris Bradley System Planning & Compliance Reliability Supervisor VAR-002 R1 & 2 VAR-001 R1,3,4,5,11 11