Experience with implementing simultaneous co-optimization in the midwest ISO energy and operating reserve markets

Abstract

The Midwest ISO will operate a day-ahead energy and operating market, a reliability assessment commitment process and a real-time energy and operating reserve market. The day-ahead energy and operating reserve market is a financially binding market that clears energy, regulating reserve, spinning reserve and supplemental reserve on an hourly basis. The reliability assessment commitment (RAC) process is a process to commit resources, schedule regulating reserve on committed resources and/or release emergency operating ranges on resources when appropriate on an hourly basis for use in the real-time energy and operating reserve market. The Midwest ISO will utilize a simultaneously co-optimized security constrained unit commitment (SCUC) algorithm and a simultaneously co-optimized security constrained economic dispatch (SCED) algorithm to operate the day-ahead energy and operating reserve market.In both the day-ahead and real-time energy and operating reserve markets, reserve requirement constraints are modeled against cumulative reserve requirements to ensure operating reserve pricing is consistent with operating reserve priority for each of the three operating reserve products. Reserve zones are also utilized to ensure dispersion of operating reserve throughout the market in a manner that allows for deliverability and good utility practice. reserve zones are established quarterly and reserve zone requirements are updated daily based on the results of off-line studies.