Mapping Document
WECC-0127 Request to Retire
VAR-002-WECC-2 Automatic Voltage Regulators
VAR-002-WECC-2 Snapshot
WECC Regional Reliability Standard (RRS), VAR-002-WECC-2 Automatic Voltage Regulators, is applicable to the Generator Operator (GOP) and the Transmission Operator (TOP) that operates synchronous condensers. The VAR only applies to synchronous generators and synchronous condensers that are connected to the Bulk Electric System (BES) and equipped with Automatic Voltage Regulation (AVR).
The single VAR-002-WECC-2 requirement states that the GOP and TOP shall have automatic voltage control in service and in automatic voltage control (AVC) mode 98% of all operating hours, unless exempted under one or more of 10 provided exemptions.
To measure performance, the GO and TOP provide quarterly reports that sum the hours meeting the requirement.
VAR-002-4 Snapshot
NERC Standard, VAR-002-4, Generator Operation for maintaining Network Voltage Schedules, is applicable to the GOP and the GO.
Although VAR-002-4 has a broader range of requirements than the VAR, the focus of this review is on Requirement R1. In VAR-002-4, R1., the GOP shall operate its generators in AVC mode with AVR in service, unless: 1) the TOP exempts the GOP from the specified operating mode; or, 2) the GOP informs the TOP that the generator will not be operating in the specified mode because of startup, shut-down, testing, or other reason. Communication between the parties is the primary measure.
Requirement R1 in the VAR is duplicates in VAR-002-4.
Background
In its original Versions 1 and 2, VAR-001-4.1 Voltage and Reactive Control allowed the TOP to exempt GOPs from operating the AVR in automatic mode. With the onset of Version 3 and later (May 9, 2012), the additional WECC Variance was added taking away the TOP’s discretion to exempt a GOP from the requirement to operate an AVR in automatic mode.[1] Although the discretion of VAR-001-X was not fully transferred to the VAR, 10 stated exclusions were added there to counterbalance that loss.
VAR-002-WECC-2 is Less Stringent
VAR-001-04.1 requires that AVRs be in operation 100% of the time, unless otherwise exempted via discretionary powers. VAR-002-WECC-2 requires AVRs be in operation 98% of the time, unless otherwise excluded by claiming under a limited universe of exclusions. This makes VAR-002-WECC-2 less stringent than VAR-001-04.1. Thus, reliability is better served under the more stringent approach of VAR-001-04.1.
Standard to be RetiredVAR-002-WECC-2 Automatic Voltage Regulators /
VAR-002-WECC-2
Requirement in Approved Standard / Addressed in Other Standards / Description and Change Justification /
98% of all operating hour
R1. Generator Operators and Transmission Operators shall have AVR in service and in automatic voltage control mode 98% of all operating hours for synchronous generators or synchronous condensers. Generator Operators and Transmission Operators may exclude hours for R1.1 through R1.10 to achieve the 98% requirement. [Violation Risk Factor: Medium] [Time Horizon: Operations Assessment]
HOW WE ARGUE ALLOWING THE TOP OFF THE COMPLIANCE HOOK?
WHAT DO WE DO WITH THE SYNCHRONOUS CONDENSORS? ARE THEY COVERED IN THE OTHER STANDARD(S)? / VAR-002-4 Generator Operation for Maintaining Network Voltage Schedules
100% of all operating hours
R1. The Generator Operator shall operate each generator connected to the interconnected transmission system in the automatic voltage control mode (with its automatic voltage regulator (AVR) in service and controlling voltage) or in a different control mode as instructed by the Transmission Operator unless: 1) the generator is exempted by the Transmission Operator, or 2) the Generator Operator has notified the Transmission Operator of one of the following: [Violation Risk Factor: Medium][Time Horizon:Real-time Operations]
• That the generator is being operated in start-up, shutdown, or testing mode pursuant to a Real-time communication or a procedure that was previously provided to the Transmission Operator;or
•That the generator is not being operated in automatic voltage control mode or in the control mode that was instructed by the Transmission Operator for a reason other than start-up,shutdown,or testing. / VAR-002-4 is superior.
The more stringent approach of VAR-002-4 better serves reliability.
98% of all operating hours
VAR-002-WECC-2 requires that Generator Operators operate AVR-equipped generators in automatic voltage mode (automatic) 98 percent of the time, excluding certain periods that qualify under the listed exemptions.
100% of all operating hours
NERC Standard, VAR-002-4, requires that Generator Operators operate generators in AVR mode when connected to the Bulk Electric System, unless instructed otherwise by the Transmission Operator, or if the Generator Operator has notified the Transmission Operator that the AVR is not operating in the automatic mode either because the generator is operating below a level the AVR can operate or for another reason.
R1.1. The synchronous generator or synchronous condenser operates for less than five percent of all hours during any calendar quarter. / VAR-002-4 “…unless otherwise exempted.” / The discretionary exemption allowed under VAR-002-4 subsumes all of VAR R1.1.
R1.2. Performing maintenance and testing up to a maximum of seven calendar days per calendar quarter.
NEED TO ADDRESS “A MAXIMUM OF SEVEN CALENDAR DAYS PER QUARTER”. WHY IS THIS NOT BETTER THAN THE VAR-004S OPEN ENDED “TESTING”? / R1, Bullet one allows for an exemption for start-up, shutdown, and testing;
R2, Bullet two allows for an exemption for “a reason other than start-up, shutdown, or testing. / Because VAR-002-WECC-2, R1, Bullets 1 and two address the testing included in VAR R1, the VAR R1 is redundant and can be deleted.
R1.3. AVR exhibits instability due to abnormal system configuration. / R3 and R4 – cover it? Verbiage. / The discretionary exemption allowed under VAR-002-4 subsumes all of VAR R1.1,
R1.4. Due to component failure, the AVR may be out of service up to 60 consecutive days for repair per incident. / WHICH ONE COVERS THIS? I THINK THE 30 MINUTES HERE IS A HIGHER THRESHOLD THAN THE 60 DAYS? GIVE ME AN AGUMENT. / The discretionary exemption allowed under VAR-002-4 subsumes all of VAR R1.1,
R1.5. Due to a component failure, the AVR may be out of service up to one year provided the Generator Operator or Transmission Operator submits documentation identifying the need for time to obtain replacement parts and if required to schedule an outage. / The discretionary exemption allowed under VAR-002-4 subsumes all of VAR R1.1,
R1.6. Due to a component failure, the AVR may be out of service up to 24 months provided the Generator Operator or Transmission Operator submits documentation identifying the need for time for excitation system replacement (replace the AVR, limiters, and controls but not necessarily the power source and power bridge) and to schedule an outage. / The discretionary exemption allowed under VAR-002-4 subsumes all of VAR R1.1,
R1.7. The synchronous generator or synchronous condenser has not achieved Commercial Operation.
R1.8. The Transmission Operator directs the Generator Operator to operate the synchronous generator, and the AVR is unavailable for service.
R1.9. The Reliability Coordinator directs Transmission Operator to operate the synchronous condenser, and the AVR is unavailable for service.
R1.10. If AVR exhibits instability due to operation of a Load Tap Changer (LTC) transformer in the area, the Transmission Operator may authorize the Generator Operator to operate the excitation system in modes other than automatic voltage control until the system configuration changes.
Mapping Document
WECC-0127 VAR-002-WECC-2 Automatic Voltage Regulators Request to Retire 6
[1] Version 3, Requiremernt R3 containing the discretion was superseded by the WECC Variance.