A novel active filter for unbalanced 3-phase 4-wire power system based on linear adaptive notch filter and fuzzy adaptive hysteresis controller

In this paper, a novel active power filter (APF) for 3-phase 4-wire power (3P4W) system under unbalanced non-linear load and various non-ideal mains voltage test cases is presented. The determination of current references for APF with 4-leg in-verter is based on linear adaptive notch filter and instantaneous symmetrical components algorithm. The fuzzy adaptive hysteresis band current control strategy is developed, where the band is modulated with the system parameters to maintain the modulation frequency nearly constant. Simulation experiment results are presented to verify the effectiveness and the viability of the proposed APF. © 2013 ICIC International.Xiaochu Qiu, Peng Shi, Jian Xiao and Jun Wan