Line harmonics reduction using neural based controller for shunt active filters

Harmonic distortion is a form of electrical noise. It is a superposition of signals, which are of multiples of fundamental frequency. Proliferation of large power electronic systems results in increased harmonic distortion. Harmonic distortion results in reduction of power quality and system stability. This paper presents neural based proportional integral (PI) control applicable for active power filters for single-phase systems, which are comprised of multiple nonlinear loads. The active filter is based on a single-phase inverter with four controllable switches, a standard H-bridge inverter. The AC side of the inverter is connected in parallel with the other nonlinear loads through a filter inductance. The DC side of the inverter is connected to a filter capacitor. The neural Pl controller is used to shape the current through the filter inductor such that the line current is in phase with and of the same shape as the input voltage. Simulation results prove that the injected harmonics are greatly reduced and system efficiency and power factor are improved.