A shunt active filter control for one-phase and three-phase four-wire systems

The proposed active filter is based on a shunt configuration made up of three one-phase current controlled VSI-PWM inverters. A deep analysis of reference and filtering waveforms during a sampling period has been carried out to obtain a relationship between electrical feedback parameters and duty cycle of switching waveform. This analysis provides a design equation for switching signal generation and effective current tracking. Simulations have been carried out to show active filter performance under highly polluting load operation. Simulation results highlight a high reduction of line current harmonic distortion with an acceptable switching frequency as well as a sensible reduction of line neutral current.