Duke Energy Carolinas (Duke), Docket No. RC12-13 (June 29, 2012)
Reliability Standard: VAR-001-1
Requirement: R6
Region: SERC
Issue: Duke, a TOP, submitted a self-report stating that it was not aware of the status of eight Power System Stabilizers (PSSs) out of the 211 generating units in its footprint. In the process of updating and reviewing VAR-001-1 documentation, Duke determined that six units at an IPP within its TOP footprint had PSSs that were enabled when the units were offline. Further review found two hydro units at its Keowee facility also had PSSs enabled when the units were offline.
Finding: The violation was deemed by SERC to pose minimal risk to BPS reliability. Once the PSSs were identified, no system or operation changes were needed. SERC stated that having or not having a PSS on a generating unit does not affect how Duke treats the units as the PSS operation is automated and needs no operator action. Also, the Automatic Voltage Regulator (AVR) on all the units is operable whether or not the PSSs are in service, and the AVRs were in automatic voltage control mode during the violation time period. The two hydro units are seldom used and have no schedule in place for their use. The other six units operate with the PSS activated while the AVR is on. GOPs are aware of the requirement to notify Duke’s System Operating Center when the AVR is off.
Find, Fix and Track Entity, Docket No. RC12-7-000 (January 31, 2012)
Reliability Standard: VAR-001-1
Requirement: R6
Region: FRCC
Issue: FFT Entity self-reported a recurring issue with VAR-001-1 R6.1. Six times FFT Entity’s energy control center violated the Standard by not communicating a voltage directive to the GO. In each of the six instances, when FFT Entity’s plant operator informed the energy control center that he needed to take the AVR to manual for maintenance (for anywhere from ten minutes to forty-eight hours), the energy control center failed to provide the plant operator with a voltage directive.
Finding: FRCC determined that this issue posed only a minimal risk to BPS reliability for two reasons. First, in each instance, the TOP was aware of the unavailability of the AVR and was maintaining voltage manually. In case of a problem, the TOP would have been able to quickly notify the RC. Second, in each instance where the energy control center failed to communicate a voltage directive, the problem occurred on units with output of less than 110 MW and 30 MVAR. FRCC did note that FFT Entity violated this Standard previously, but determined that because of the minimum level of risk created by the errors and the enhanced steps FFT Entity implemented in 2009 to avoid future problems, the problem merited only FFT treatment.
Orlando Utilities Commission (OUC), Docket No. RC13-10, June 27, 2013
Reliability Standard: VAR-001-1
Requirement: R6
Region: FRCC
Issue: OUC, as a TOP, self-reported to FRCC that it had an issue with VAR-001-1 R6 when it found that it did not know the status of all transmission Reactive Power resources, including the status of voltage regulators.
Finding: FRCC determined that the issue posed a minimal risk to the reliability of the BPS because the TOP’s voltage regulator was set to automatic in MVAR control, rather than in a manual mode, and the actual mode of control for the unit’s regulator did provide a level of voltage stability to the BPS.
Westar Energy, Inc. (Westar), Docket No. RC13-1 (October 31, 2012)
Reliability Standard: VAR-001-1
Requirement: 1
Region: SPP
Issue: While conducting a Compliance Audit of Westar, as a TOP, the SPP Audit Team found that Westar was noncompliant with VAR-001-1 R1 because Westar's policy for monitoring and controlling voltage levels and Mvar flows lacked sufficient procedural instructions to ensure that its transmission system operators could monitor and control voltage levels and Mvar flows within Westar's individual areas and with the areas of the neighboring TOPs. The Audit Team reported that Westar's policydid not have records of Westar's generator voltage schedules; a procedure for how to obtain target system voltage (only the voltage range was defined within the policy); a procedure to explain what actions are necessary when addressing Mvar flow; and a procedure for automatic control for reactive devices on the Westar system.
Finding: SPP found the issue posed minimal risk to BPS reliability. Even though Westar's plan failed to contain all required information, Westar's transmission system operators provide voltage schedules to the Westar generating plants. Westar's System Operating Manual sets forth a target system voltage by stating a voltage range based on a percentage of the nominal voltage. System operators operate to the representative nominal voltage and within the range identified. Even though Westar failed to address when reactive resources are activated within its System Operating Manual, transmission system operators monitor voltage-ampere reactive (VAR) flows via the Westar supervisory control and data acquisition (SCADA) system and utilize manual and automatic control of reactive resources to control system voltage.
