Direct power fuzzy control of shunt APF

A method of direct power fuzzy control is proposed for shunt active power filter to eliminate the harmonics brought by nonlinear load and compensate the reactive power,removing the restriction of hysteresis bandwidth on switching-frequency in traditional direct power control.The instantaneous power are analyzed and calculated based on the instantaneous power theory.The deviation of instantaneous active / reactive power is used as the fuzzy logic control variable and sent to the fuzzy rule base and the switching state signal is generated by the fuzzy rules.Without power hysteresis comparators and conventional switching table,the proposed control method is more flexible and efficient.Simulative results show that,the controlled shunt active power filter has better static and dynamic performance and the DC-side voltage control has fast accuracy and robustness,resulting in the sinusoidal grid-side current with unity power factor.