NOTICE DATE: March 30, 2023

NOTICE TYPE: W-A033023-01 Operations

SHORT DESCRIPTION: Annual Under-Frequency Load Shedding (UFLS) survey of Transmission Operators

INTENDED AUDIENCE: ERCOT Transmission Operators (TOs)

DAYS AFFECTED: May 11, 2023, 11:00 a.m.; July 14, 2023.

LONG DESCRIPTION: In accordance with Nodal Operating Guide Section 2.6.1, Automatic Firm Load Shedding, ERCOT requests that all ERCOT TOs complete the attached UFLS survey.  

The survey must be completed for a test hour on May 11, 2023, at 11:00 a.m. Central Prevailing Time (CPT). Each ERCOT TO is required to plan to secure the measured load for the above test hour.

ACTION REQUIRED: ERCOT appreciates your cooperation and asks that the attached survey be completed and submitted no later than July 14, 2023 via e-mail to [log in to unmask].

ADDITIONAL INFORMATION: ERCOT has prepared the attached survey form for use by ERCOT TOs to report data collected from the test hour of May 11, 2023 at 11:00 a.m. CPT.

• If the data cannot be collected for the selected test hour for any reason, including equipment failure, please submit the information for an hour that is as close to the selected test hour as possible.

• Please include the total load to shed for Under Frequency Relay set points of 59.3 Hz, 58.9 Hz and 58.5 Hz corresponding to load relief of at least 5%, 15%, and 25% of the TO load, respectively.

• If utilized, please include the load to shed for the optional load relief requirements for the Supplemental Anti-Stall UFLS Stages at the three thresholds of 90, 120, and 150 seconds at 59.5 Hz corresponding to load relief of at least 1.5%, 3.0%, and 4.5% of the TO load, respectively.

• ERCOT TOs are asked to list the ERCOT-registered TDSPs included in their survey for which they are the designated ERCOT TO. Please list these TDSPs by Load area or using the comment section of the survey.

• Please complete both tabs on the survey form. The second tab includes additional relay information.

• Please use the attached “2023 UFLS Survey Spreadsheet” and the same naming convention for any other supporting documentation submitted with the survey.

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].

If you are receiving email from a public ERCOT distribution list that you no longer wish to receive, please follow this link in order to unsubscribe from this list: http://lists.ercot.com.

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