UNIT COMMITMENT USING FUZZY DYNAMIC PROGRAMMING

Abstract

Unit commitment is a typical optimization problem in which generally the objective function to be minimized-is the production cost over the study period and the constraints imposed on the system include power generation-load balance, spinning reserve requirements, emission constraint and the constraints imposed on the units such as power generation limits, minimum up-time, minimum down-time etc. The application of fuzzy dynamic programming to the unit commitment problem is den-ionstrated. Fuzzy logic employs linguistic terms which deals with the casual relationship between input and output variables. This method allows a qualitative description of the behaviour of, a system, the system's characteristics, and response without the need for exact mathematical formulations. In order to comply with environmental regulations, environmental pollutants (i.e. NON, COx and SO,c) are also considered in the objective function. Such conflicting objective (i.e. production cost and emission cost) are easy tohandle using this approach. It is demonstrated through a numerical example that a fuzzy logic based approach achieves .a logical and feasible, economically and 'env-iron-mentally best, state of operation of power system, which is the major objective of the- unit commitment. The problem is formulated using both- triangular and trapezoidal at varying overlaps. All work has been done on TATA ELXSI system under IRIX 5.3 environment.