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NOTICE DATE: June 1, 2021

NOTICE TYPE: M-C060121-01 Operations

SHORT DESCRIPTION: 2021 Summer and Fall Seasonal Voltage Profiles

INTENDED AUDIENCE: Resource Entities (REs), Qualified Scheduling Entities (QSEs), Transmission Operators (TOs), Transmission Service Providers (TSPs), NERC-registered Generator Operators (GOPs), and Transmission Operators (TOPs)

DAYS AFFECTED: June 1, 2021

LONG DESCRIPTION: ERCOT has posted the 2021 Summer (June 1, 2021 - August 30, 2021) and 2021 Fall (September 1, 2021 - November 30, 2021) Voltage Profiles, which include Voltage Set Points for each Generation Resource's Point of Interconnection (POI). ERCOT and the TSPs derived these Voltage Profiles after a series of joint studies and meetings. In accordance with NERC Reliability Standard VAR-001-4.2 R5, the posted spreadsheet lists seasonal Voltage Set Points for every Generation Resource at its POI in columns G and K, and W and AA. Voltage Set Points at the high side of the step-up transformer are listed in columns M and O, and AC and AE.

As required by ERCOT Nodal Protocols Section 6.5.7.7(5), each Generation Resource operator shall follow the Real-Time Voltage Set Point instruction given by ERCOT or the TSP. Any operator of one or more Generation Resources, including any NERC-registered GOP, whose Voltage Set Point in the posted Voltage Profile for each upcoming season differs from its Real-Time Voltage Set Point should coordinate with its TSP to determine if changes to the Real-Time Voltage Set Point are needed.

ERCOT reminds all Generation Resource operators that the response to a TO Voltage Set Point instruction must be completed in no more than five minutes from receipt of the instruction under ERCOT Nodal Operating Guide Section 2.2.10(3)(b). Additionally, in accordance with ERCOT Nodal Protocols Section 3.15.3, each Generation Resource AVR must be operated in the automatic voltage control mode and set to control the POI voltage to the Voltage Set Point. In accordance with ERCOT Nodal Operating Guide Section 2.7.3.5(3), a Resource Entity shall inform its QSE and either the Resource Entity or its QSE shall notify the Resource Entity’s TO, as soon as practicable, but not longer than 15 minutes from receipt of the instruction by the Resource Entity, if it cannot comply with TO Voltage Set Point instructions, or not longer than 30 minutes from being outside of the tolerance band if it cannot maintain the POI voltage within the tolerance band. If a Resource Entity cannot comply with a VSS Dispatch Instruction, the Resource Entity shall inform its QSE and its QSE shall notify ERCOT as soon as practicable but not longer than 15 minutes from the receipt of the instruction by the Resource Entity.

In accordance with ERCOT Nodal Operating Guide Section 2.7.3.5(4), a Resource Entity required to provide Voltage Support Service (VSS), including any NERC-registered GOP, must maintain the generator voltage or Reactive Power schedule to maintain voltage at the POI to be within the tolerance band of the Voltage Set Point while operating at less than or equal to the maximum reactive capability of the Generation Resource.

ADDITIONAL INFORMATION: The 2021 Summer and Fall Seasonal Voltage Profiles can be found on the ERCOT Market Information System (MIS) under Voltage Profile s on the Group Reports section, under Transmission Service Providers. A Digital Certificate is required to access the MIS.

CONTACT: If you have any questions, please contact your ERCOT Account Manager. You may also call the general ERCOT Client Services phone number at (512) 248-3900 or contact ERCOT Client Services via email at [log in to unmask].

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