Fuzzy Selftuning PI Controller for PhaseShifted S eries Resonant Converters

A linearized model of the phase-shifted series resonant converter is necessary for closed loop design. With fixed PI con- trol design, the converter does not have good disturbance rejec- tion capability and cannot always cope with a wide range of un- certainties. In this paper, a PI self-tuning mechanism based on a fuzzy logic scheme is proposed. It corrects the PI gains, initially designed using small-signal modeling, to improve converter dy- namic response and disturbance rejection. The algorithm is based on continuous change/adaptation of the PI gains until best dynamic response is achieved. Simulation results compare res- ponses for the PI fixed parameters with the fuzzy-adapted con- troller gains under different disturbance conditions.