Rationale for R5: The new requirement provides transparency regarding the criteria used by the TOP to establish This requirement also provides a vehicle for the TOP to use appropriate the voltage schedule. granularity when setting notification requirements for deviation from the voltage or Reactive Power schedule. Additionally, this requirement clarity regarding a as provides “tolerance band” specified in the voltage schedule and the control dead-band in the system. generator’s excitation Voltage Schedule tolerances are the bandwidth that accompanies the voltage target in a voltage schedule, should reflect the anticipated fluctuation in voltage at the Generation Operator’s facility during normal operations, and be based on the assessment of and TOP’s N‐1 credible N‐2 system contingencies. The voltage bandwidth should not be confused with the control schedule’s that is programmed into a Generation automatic voltage control dead‐band Operator’s regulator’s system, which should be adjusting the AVR prior to reaching either end of the voltage schedule’s bandwidth. Rationale for R6: Although tap settings are first established prior to interconnection, this requirement could not be deleted because no other standard addresses when a tap setting must be adjusted. If the tap setting is not properly set, then the amount of VARs produced by a unit can be affected. Version History Version Date Action Change Tracking 0 April 1, 2005 Effective Date New 1 August 2, 2006 BOT Adoption Revised 1 June 18, 2007 FERC approved Version 1 of the Revised standard. 1 July 3, 2007 and Errata Added “Generator Owners” to Applicability “Generator Operators” section. 1 August 23, Removed and Errata “Generator Owners” 2007 to Applicability “Generator Operators” section. 2 August 5, 2010 Adopted by NERC Board of Trustees; Revised Modified to address Order No. 693
Rationale for R5: The new requirement provides transparency regarding the criteria used by the TOP to establish the voltage schedule. This requirement also provides a vehicle for the TOP to use appropriate granularity when setting notification requirements for deviation from the voltage or Reactive Power schedule. Additionally, this requirement provides clarity regarding a “tolerance band” as specified in the voltage schedule and the control dead-band in the generator’s excitation system. Voltage Schedule tolerances are the bandwidth that accompanies the voltage target in a voltage schedule, should reflect the anticipated fluctuation in voltage at the Generation Operator’s facility during normal operations, and be based on the TOP’s assessment of N‐1 and credible N‐2 system contingencies. The voltage schedule’s bandwidth should not be confused with the control dead‐band that is programmed into a Generation Operator’s automatic voltage regulator’s control system, which should be adjusting the AVR prior to reaching either end of the voltage schedule’s bandwidth. Rationale for R6: Although tap settings are first established prior to interconnection, this requirement could not be deleted because no other standard addresses when a tap setting must be adjusted. If the tap setting is not properly set, then the amount of VARs produced by a unit can be affected. Version History Version Date Action Change Tracking 0 April 1, 2005 Effective Date New 1 August 2, 2006 BOT Adoption Revised 1 June 18, 2007 FERC approved Version 1 of the standard. Revised 1 July 3, 2007 Added “Generator Owners” and “Generator Operators” to Applicability section. Errata 1 August 23, 2007 Removed “Generator Owners” and “Generator Operators” to Applicability section. Errata 2 August 5, 2010 Adopted by NERC Board of Trustees; Modified to address Order No. 693 Revised
WECC-0128%20Posting%202%20VAR-001-4.1.%20Existing%20redlined%20to%20Posting%202.docx