Fuzzy controlled braking resistor scheme to enhance transient stability of a synchronous generator

摘要

A fuzzy system based braking resistor scheme is proposed to enhance the transient stability of a synchronous generator connected to an infinite bus bar. The rotor speed deviation is taken as input for fuzzy controller and the conductance to be included is considered as output. From the conductance, the proportional firing-angle for the thyristor-controlled switch is determined. By controlling the firing-angle, the accelerating power in generator is controlled and thus improves the transient stability. The effectiveness of the proposed controller has been demonstrated by considering balanced (3LG: three-phase-to-ground) fault near the generator terminals. Simulation is carried out with the proposed fuzzy control scheme. The simulation results are presented. The effects of various membership functions on the accuracy of fuzzy controller were also investigated.