Associated Electric Cooperative, Inc. (AECI), Docket No. RC12-13 (June 29, 2012)
Reliability Standard: VAR-002-1
Requirement: R1
Region: SERC
Issue: AECI, a GO, submitted self-reports in October 2010 and February 2011 disclosing that it found several units at two of its plants had been operating with the automatic voltage regulators (AVRs) on and in control of voltage, but AECI could not find evidence that it had notified its TOP that the units were operating in a mode other than automatic voltage control.
Finding: The issue was deemed by SERC to pose minimal risk to BPS operations as AECI kept its voltage level inside the boundaries set by its TOP and it could respond to any required changes during the relevant time period. The first self-report involved 321 MW of generation, which equaled 6.1% of AECI’s total capacity of 5,255 MW. That plant was operating at a 2% capacity factor. The second self-report involved 629 MW of generation, which equaled 12.0% of the total capacity of AECI. That plant was operating at a 37.5% capacity factor.
Find, Fix, Track and Report, Docket No. RC12-2 (November 30, 2011)
Reliability Standard: VAR-002-1
Requirement: R1
Region: RFC
Issue: FFT Entity failed to notify its Transmission Operator when it operated outside automatic voltage control mode.
Finding: RFC determined that this issue posed a minimal risk and did not pose a serious or substantial risk to the reliability of the BPS which was mitigated because, since the generators operated in reactive power mode, voltage support to the BPS continued, although to a lesser degree, while the generators were not in automatic voltage control mode.
Find, Fix, Track and Report, Docket No. RC12-2 (November 30, 2011)
Reliability Standard: VAR-002-1
Requirement: R1
Region: RFC
Issue: FFT Entity had an issue with VAR-002-1 R1 by failing to notify its Transmission Operator when it operated outside automatic voltage control mode.
Finding: RFC determined that this issue posed a minimal risk and did not pose a serious or substantial risk to the reliability of the BPS which was mitigated because, since the generator in question (which only has a capacity of less than 100 MW and interconnects to the transmission system at a lower voltage) automatically controlled for VARs, voltage support to the BPS continued, although to a lesser degree. Additionally, the plant met all of the voltage schedules as provided by its TOP during the period of the issue. Lastly, FFT Entity reported that the particular generator is not called upon by its TOP to support transmission system voltage.
Find, Fix and Track Entity, Docket No. RC12-6 (December 30, 2011)
Reliability Standard: VAR-002-1
Requirement: R1, R3
Region: ReliabilityFirst
Issue: FFT Entity self-reported that it failed to operate its automatic voltage regulators (AVRs) in automatic voltage control mode since FFT Entity first operated the AVRs with VAR control mode in place believing that the VAR condition maintained a constant generator terminal voltage. FFT Entity initially relied on guidance from the manufacturer, but upon further review, it realized VAR mode was not the same as operating the AVRs in automatic voltage control mode as set forth by R1 of the Standard and that the AVRs needed to be in the OFF mode in order for automatic voltage control mode to run. A violation of R3 occurred as FFT Entity did not notify its TOP within 30 minutes of a status change to its AVRs.
Finding: ReliabilityFirst found the issue constituted a minimal risk to BPS reliability because even though the AVRs were not in automatic voltage control mode, they remained in VAR mode, which would allow them to respond to any voltage changes. Also, FFT Entity stated that it has complied with any directive given by its TOP related to its generating station voltage schedule.
Find, Fix and Track Entity, Docket No. RC12-6 (December 30, 2011)
Reliability Standard: VAR-002-1
Requirement: R1
Region: SERC
Issue: FFT Entity self-reported that it failed to operate its automatic voltage regulators (AVRs) in automatic voltage control mode. FFT Entity received a technical bulletin describing that AVRs need to be in the OFF mode in order for automatic voltage control mode to run. After reviewing the status of its generators, FFT Entity realized it was not operating in automatic voltage control mode, which then created non-compliance with the requirement in VAR-002-1 R1 that the TOP be notified of any instance of a generator not operating in automatic voltage control mode.
Finding: SERC found the issue constituted a minimal risk to BPS reliability because no voltage-related reliability issues had occurred and FFT Entity had met its voltage schedules until the plant was taken offline and switched for VAR to automatic voltage control mode. Also, the AVRs were in an operating mode that should have allowed FFT Entity to respond to any BPS requests for support.
Lake Road Generating Company, LP (Lake Road), Docket No. RC13-6-000 (February 28, 2013)
Reliability Standard: VAR-002-1
Requirement: 1, 3
Region: NPCC
Issue: Lake Road, a GOP, submitted a self-report to NPCC on July 22, 2011, explaining that, since June 21, 2007, its three generating units had been operating in reactive power control mode rather than automatic voltage control mode. Lake Road reported that it was not clear on its notification requirements regarding automatic voltage regulator (AVR) controls at generating facilities until viewing a NERC industry webinar on July 15, 2011. Lake Road reported that it had not notified its TOP that it was not operating in automatic voltage control as required by R1 nor within the 30-minute notification requirement under R3 in violation of the Reliability Standard.
Finding: NPCC found the issue posed minimal risk to BPS reliability because even though the AVRs were controlling reactive power, Lake Road was following the TOP-provided voltage schedule during the relevant time period.
South Carolina Electric & Gas Company (SCE&G), Docket No. RC13-7-000 (March 27, 2013)
Reliability Standard: VAR-002-1
Requirement: 1
Region: SERC
Issue: SCE&G submitted a Self-Certification to SERC in October 2012 stating that, as a GO, it could not demonstrate that it had alerted its TOP that the automatic voltage regulator (AVR) at each of its plants was not operating in automatic voltage control mode. Two plants used VAR control mode based on a TO-provided system reliability study; and one AVR was in power factor control mode as a result of an oversight. SCE&G had no evidence that the TOP had been notified of the different voltage control modes.
Finding: The issue was deemed to pose minimal risk to BPS reliability and not serious or substantial risk. The AVR at two plants was operating in the mode best suited for system reliability. During the relevant time period, SCE&G kept its voltage schedules and was able to respond as required. Also, SCE&G plants and system control regularly communicate to ensure overall system reliability. No misoperations occurred during the relevant time period.
