Shunt active power filter control using fuzzy logic controllers

This paper presents a shunt active filter which eliminates current harmonics and compensates the reactive power of the load. The majority of shunt active power filter control methods which have been presented require a complex and sophisticated mathematical model, especially for the tuning of the PI controllers. To simplify and improve the shunt active filter control system, fuzzy logic theory is applied. In this paper, by the way of controlling the capacitor voltage of the dc bus a fuzzy logic algorithm is implemented. One such algorithm is also implemented to control the output current of the inverter. The performance of the capacitor voltage fuzzy logic control system was investigated, and the improvement of the dynamic response of the fuzzy controller compared to the conventional PI controller became evident. For the reduction of the grid current THD_i index, a fuzzy logic hysteresis current controller is investigated. In order to improve the performance of shunt active filter under non ideal grid voltages, a modified version of the p-q theory is proposed. The simulation results are presented and discussed showing the advantages of fuzzy logic theory in the dc bus voltage control and current control.