Reactive power optimization using fuzzy load representation

This paper presents a mathematical formulation for the optimal voltage/reactive power control problem taking into account linguistic declaration of system load values. The fuzzy set theory which is based on the feasibility rather than the frequency of occurrence of an outcome is considered, and possibility distributions are assigned to load values and bus voltages. The objective is to minimize power losses considering various load conditions. The problem is decomposed into four subproblems via the Dantzig-Wolfe decomposition for reducing the dimensions of the problem. A second Dantzig-Wolfe decomposition divides each subproblem into several areas leading to a considerable reduction in the dimensions of subproblems. An illustrative example demonstrates the applicability of the approach. The fuzzy approach provides a global solution for the system behavior under various load conditions