Reliability Standard: VAR-002-1.1a
Requirement: R1
Region: SPP
Issue: AEPW, in its role as a GOP, submitted a self-report in October 2010 explaining that its Stall power plant had operated its automatic voltage regulator (AVR) in manual Voltage and Reactive Power (VAR) mode for 48 days after its commercial operations date without alerting the TOP. Pursuant to the Standard, any VAR operating mode other than automatic must be reported to the TOP. AEPW explained that system operators were unaware that the AVR was running in manual VAR control mode and therefore it was not reported to the TOP.
Finding: The issued was deemed by SPP to pose minimal risk to BPS reliability because during the period in question AEPW monitored and maintained the proper voltage schedule. In addition, an earlier study had shown that if the unit was providing no VAR support, no quantifiable change in system voltage would occur. No misoperations were reported resulting from AEPW not notifying its TOP.
Reliability Standard: VAR-002-1.1a
Requirement: R3
Region: TRE
Issue: Panther Creek I & II Wind Farm, as a GOP, self-certified to TRE that it had an issue with VAR-002-1.1a R3 when it found that in one instance it did not communicate a change in reactive capability to its TOP. The issue arose when there was a general failure of the GOP’s operators to communicate the change in reactive capability status.
Finding: TRE determined that the issue posed a minimal risk to the reliability of the BPS because the GOP operators continuously monitored voltage levels, supported by alarms set to trigger on deviations away from voltage profile limits. In addition, the GOP experienced no voltage issues with their systems during the issue period.
Reliability Standard: VAR-002-1.1a
Requirement: R3
Region: TRE
Issue: Panther Creek III Wind Farm, as a GOP, self-certified to TRE that it had an issue with VAR-002-1.1a R3 when it found that in six instances it did not communicate a change in reactive capability to its TOP. The issue arose when there was a general failure of the GOP’s operators to communicate the change in reactive capability status.
Finding: TRE determined that the issue posed a minimal risk to the reliability of the BPS because the GOP operators continuously monitored voltage levels, supported by alarms set to trigger on deviations away from voltage profile limits. In addition, the GOP experienced no voltage issues with their systems during the issue period.
Entergy, Docket No. RC12-16-000 (September 28, 2012)
Reliability Standard: VAR-002-1.1a
Requirement: 1, 3
Region: SERC
Issue: On June 8 and June 14, 2011, Entergy, a GOP, self-reported violations of VAR-002-1.1a/1 and 3, with both violations stemming from Entergy's AVR switching from automatic to manual mode on August 16, 2010. Regarding the violation of R1, Entergy failed to notify the TOP that their AVR switched from automatic voltage control mode to manual mode after a station service transformer breaker tripped. Regarding the violation of R3, Entergy failed to provide evidence that it notified the TOP within the mandated thirty minute window of the AVR's status change. While Entergy was able to document both that the station service power was lost for nine minutes and nine seconds and that the AVR was back in automatic voltage control ten to fifteen minutes following the loss of power, Entergy was unable to provide evidence that the TOP was notified.
Finding: SERC determined that the issue posed only a minimal risk to the reliability of the BPS for two reasons. First, compared to the three units online at the time of the occurrence, each generating 125 MW (100% capacity), 500 MW (79% capacity) and 740 MW (100% capacity) respectively, the unit at issue provided only a small fraction of the station's capability. Second, throughout the occurrence, Entergy's operator was aware of the condition, manually controlling the voltage, and working to restore the AVR to automatic mode.
Find, Fix and Track Entity, Docket No. RC11-6 (September 30, 2011)
Reliability Standard: VAR-002-1.1a
Requirement: R2
Region: RFC
Issue: As the result of a compliance audit, RFC determined FFT Entity violated R2 because it operated outside of the voltage schedule set by its TOP by up to -5 kV without an exemption.
Finding: RFC found that this issue constituted only a minimal risk to bulk power system reliability because the FFT Entity operated its voltage regulators in automatic VAR mode, and its voltage schedule reflected a relatively narrow bandwidth that would not have deviated from the revised voltage schedule FFT Entity subsequently established with its TOP.
Find, Fix, Track and Report, Docket No. RC12-2 (November 30, 2011)
Reliability Standard: VAR-002-1.1a
Requirement: R1, R3
Region: SERC
Issue: FFT Entity self-reported that it failed to operate each generator in the automatic voltage control mode, as required (R1). In addition, FFT Entity self-reported that it did not notify its TOP of the status change in the automatic voltage regulator (AVR) operation, as required (R3).
Finding: SERC staff determined that the issue posed a minimal risk and did not pose a serious or substantial risk to the reliability of the BPS because the unit maintained its voltage schedule, the incident involved only one unit at the facility, which consists of three units with a total capacity of over 500 MW, FFT Entity did not identify any other instance of its generators operating with its AVR out of service without appropriate communication to its TOP after review of its records.
Reliability Standard: VAR-002-1.1a
Requirement: 2
Region: RFC
Issue: RFC conducted a compliance audit during which it found that NIPSCO, as a GOP, violated R2 of VAR-002-1.1a, in that its 160MW Baily Unit 7 generating unit failed to meet its voltage schedule on June 10, 2009 and August 9, 2011. Specifically, NIPSCO's Unit 7 was not functioning at its MVAR limit and was not exempted to function outside of its voltage schedule. Furthermore, RFC found that from October 3, 2010 to November 29, 2010, when Unit 7's AVR was experiencing outage, NIPSCO failed to maintain Unit 7's voltage within its voltage schedule on all days except 13 days.
Finding: RFC found that the issue posed a minimal risk to the reliability of the bulk power system because all the excursions were minor, with the voltage schedule allowing for excursions of +/- 1%. The largest excursion was 1.87 kV of the tolerance band. RFC remediated the issue by receiving an expanded voltage schedule, which, had it been used during the audit period, would not have caused a violation of R2 of VAR-002-1.1a.
NRG Rockford LLC, FERC Docket No. RC12-11 (April 30, 2012)
Reliability Standard: VAR-002-1.1a
Requirement: R2
Region: RFC
Issue: During a compliance audit, RFC found that on July 6 and 7, 2010, NRG Rockford LLC’s (NRG Rockford) Unit 11 was under its voltage schedule for approximately five hours on each day.
Finding: RFC found that this issue constituted only a minimal risk to the BPS. NRG Rockford is located in the middle of Commonwealth Edison Company’s 138 kV system and had limited ability to unilaterally raise system voltage. In addition, NRG Rockford was operating at less than 5% outside of its assigned voltage schedule and it was operating at maximum reactive power (even through it was still below the assigned voltage schedule).
NRG Rockford II LLC, FERC Docket No. RC12-11 (April 30, 2012)
Reliability Standard: VAR-002-1.1a
Requirement: R2
Region: RFC
Issue: During a compliance audit, RFC found that on August 10 and 12, 2010, NRG Rockford II LLC’s (NRG Rockford) Unit 21 was under its voltage schedule for approximately 8.5 and 7 hours, respectively.
Finding: RFC found that this issue constituted only a minimal risk to the BPS. NRG Rockford II is located in the middle of Commonwealth Edison Company’s 138 kV system and had limited ability to unilaterally raise system voltage. In addition, NRG Rockford II was operating at less than 5% outside of its assigned voltage schedule and it was operating at maximum reactive power (even through it was still below the assigned voltage schedule).
Owensboro, KY Municipal Utilities (OMU), Docket No. RC12-12 (May 30, 2012)
Reliability Standard: VAR-002-1.1a
Requirement: R2
Region: SERC
Issue: OMU, in its role as a GOP, submitted a self-report disclosing that operation outside of the voltage schedule set forth by its TOP had occurred on 26 occasions. On no occasion was the deviation greater than 2% outside the voltage schedule. During the relevant period, OMU had no exception from its TOP nor did the TOP indicate any concern regarding the deviations.
Finding: The issue was found to pose minimal risk to BPS reliability because the voltage was regulated by OMU and was within 1.6% of the directed voltage schedule as determined by its TOP. And, OMU was not contacted by its TOP about the issue.
Papalote Creek I, LLC (Papalote Creek I Wind Farm), Docket No. RC13-10, June 27, 2013
Reliability Standard: VAR-002-1.1a
Requirement: R3
Region: TRE
Issue: Papalote Creek I Wind Farm, as a GOP, self-certified to TRE that it had an issue with VAR-002-1.1a R3 when it found that on nine instances between July 9, 2010 to October 6, 2010 the GOP failed to communicate a change in reactive capability its TOP due to a general failure of its operators to communicate the change in reactive capability status.
Finding: TRE determined that the issue posed a minimal risk to the reliability of the BPS because the GOP’s operators were continuously monitoring voltage levels, and there were alarms set to trigger if any deviations form voltage profile limits occurred. In addition, the GOP did not experience any voltage issues with its systems during the issue period.
