FUZZY OPTIMAL REACTIVE POWER-CONTROL

Optimal reactive power control has been an active research area during the last decade. Where precise data are available, a specific objective with clear-cut constraints was the primary requirement. The sensitivity of a feasible solution in the constraint domain has been reported many times. Fuzziness and imprecision often arise due to poorly defined data, objectives, constraint boundaries and imperfect modeling. In the past few years, fuzzy modeling of such an optimization problem in mathematical programming has been developed and at present is still one of the active research areas in fuzzy set theory applications. In this paper, a fuzzy single-objective function with multiple fuzzy constraints is modeled by fuzzy set theory. Trapezoidal membership functions an defined for the objective function and constraints. Then the fuzzy mathematical programming of the reactive power control is reformulated as a standard linear programming problem and the lambda-formulation method is applied for its solution. Ward-Hale 6-bus and IEEE 14-bus test systems are used as illustrative numerical examples and the results of the presented methodology are compared with conventional methods. The results of the computation are optimistic both in terms of minimizing the objective function and of the smaller number of iterations with respect to the previous methods.