Fuzzy self-tuning PI controller for phase-shifted series resonant converters

A linearized model of the phase-shifted series resonant converter is necessary for closed loop design. With fixed PI control design, the converter does not have good disturbance rejection capability and cannot always cope with a wide range of uncertainties. 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 dynamic 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 responses for the PI fixed parameters with the fuzzy-adapted controller gains under different disturbance conditions.