Power System Stabilizing Control Based on Simplification of Constructing Fuzzy Control Rules

Electric power system has been associated with a lot of uncertainties, such as constant change of loads and system operation, because of becoming large scale and complexity. A fuzzy control has been applied to some of power system studies. The aim of this paper is to propose a method of stabilizing control based on fuzzy theory for electric power system and to apply it numerically and experimentally for a one-machine infinite bus power system. The method is constructed under the knowledge of the equal-area method used for the transient stability analysis. In the method, variables of condition parts and rules are simplified, and the number of membership functions of fuzzy control is minimized, by a coordinate transformation with the rotation angle on the phase plane. Furthermore, we discuss the stabilizing control during fault condition. The proposed method gives a good efficiency during fault, because it has great potential that the implementation of fuzzy control does not always require the use of a mathematical model and the control input can be determined in a short time using only a qualitative statement of control rules. Simulation results for numerical calculation and experimentation show that the method yields good system dynamic performance.