NOTICE DATE:  November 4, 2016
NOTICE TYPE:  M-B110416-01 NPRR/SCR
SHORT DESCRIPTION:  Implementation Details of SCR788
INTENDED AUDIENCE:  ERCOT Market Participants
DAY AFFECTED:  December 6 - December 8, 2016
LONG DESCRIPTION:  From December 6 - December 8, 2016, ERCOT will implement System Change Request (SCR) 788, Addition of Integral ACE Feedback to GTBD Calculation, which was approved by the ERCOT Board on June 14, 2016.
This SCR updates the formula used by the Resource Limit Calculator to calculate the Generation To Be Dispatched (GTBD) value. The updated formula for GTBD will include the addition of Area Control Error (ACE) Integral times a configurable factor that captures the long-term Dispatch trend to help minimize GTBD oscillations from one Security-Constrained Economic Dispatch (SCED) interval to the next.
This change will result in the GTBD being calculated as the following:

GTBD = Total Gen + K1*10*System Load Frequency Bias + K2*[(net non-conforming Load) - (net filtered non-conforming Load)] + K3*5*PLRR + K4*Regulation Deployed + K5*ACE Integral

            |ACE Integral| ˜ Max Integral ACE Feedback

            |Regulation Deployed| ˜ Max Regulation Deployed Feedback

Upon activation, the configuration factors in GTBD will be tuned to start including ACE Integral. The specific date and time of the activation of the change will be communicated in a subsequent update.

ADDITIONAL INFORMATION:  SCR788<http://www.ercot.com/mktrules/issues/SCR788> and associated documents can be found on the ERCOT website.
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]<mailto:[log in to unmask]>.
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