Fuzzy hysteresis based direct power control for three-phase voltage source rectifier

In order to alleviate the contradiction between the switching loss and the control precision existing in the traditional direct power control (DPC), a novel fuzzy hysteresis based DPC (FH-DPC) is proposed for the three-phase voltage source rectifier. In the proposed FH-DPC, the outputs of the fuzzy hysteresis controller, which is designed based on the relationship between the switching loss and the control precision, are sent to the switching table. The best switching states, which regulate the active and reactive power simultaneously, then will be selected. The effectiveness of the FH-DPC is verified with the simulation and experiment. The unity power factor is obtained with the FH-DPC. Compared with the traditional DPC, the current total harmonic distortion rate (THD) of the FH-DPC is reduced by 53%, and the total action time of the switch is reduced by at least 11.8%. The results indicate that the better control accuracy and the less switching loss can be achieved with the FH-DPC.