AN APPROXIMATE REASONING APPROACH FOR OPTIMAL DYNAMIC DISPATCH OF THERMAL GENERATING-UNITS INCLUDING AUXILIARY CONTROL

This paper proposes to apply fuzzy set theory to decision-making in optimal generation dispatch of thermal generating units. Operational requirements such as unit auxiliary start-up and shutdown cast discrete zones on generation output. Plant operators are required to switch units dynamically from one output zone to another in order to keep track of changing load. The problem arises when making the decision of switching zones for the dynamic load dispatch, because of complicated operational conditions. We apply approximate reasoning in order to coordinate multiple system requirements and to make effective zone-switching decisions. Membership functions are introduced to measure generation-load balance, fuel cost, and time to stay in a zone. Approximate reasoning using these indices yields an information of a compatibility of output zones. Model analysis is employed to demonstrate the flexibility and improved man-machine interface of the approach.