Optimal Short Term Thermal Unit Commitment Using Fuzzy Logic

Abstract

Economic dispatch and Unit Commitment are widely used for the real time operation of power system. The effectiveness of economic dispatch is well understood when the objective is to schedule the committed generators to meet the load, maintain voltages and frequency within prescribed tolerances and minimize operating cost without unduly stressing the equipment. An approach for solving the unit commitment problem using fuzzy logic has been proposed in this thesis. It is demonstrated through numerical problem that a fuzzy logic based approach achieves a logical and feasible economical cost of operation of the power system. The solution of the problem is also obtained using Dynamic Programming. A set of linguistic fuzzy control rules are developed to establish the relationship between the inputs and the output. The fuzzy variables associated with the unit commitment are Load demand, Incremental cost, Start up cost and Power generation. The approach has been applied to a system comprised of 3 generating units. A MATLAB code has been developed for solving fuzzy logic based unit commitment problem. Results indicating comparison of the cost solutions using the fuzzy logic and the conventional Dynamic Programming are also presented in this work.