Enhancing optimal excitation control by adaptive fuzzy logic rules

Generator excitation system plays an important role in maintaining power system stability. A new fuzzy control strategy is introduced to enhance excitation control by online coordinating Automatic Voltage Regulator (AVR) and Power System Stabilizer (PSS) control tunnels. The method automatically adjusts the weights of the AVR tunnel and PSS tunnel on-line according to different operating conditions by a set of fuzzy logic rules, aiming to improve the overall optimal excitation control performance by the coordination of voltage control and dynamic stability control. The requirements of excitation control in different circumstances are studied, and the fuzzy rules of the coordination are presented. The structure of the presented controller is simple and clear while the conventional design methods in AVR and PSS control tunnels can be kept without change. Numerical simulation results on two cases under different disturbances demonstrate that the proposed controller can get a good performance for a variety of the operating conditions.