Simulation of a current source APF for a single phase system feeding a non-linear load / Khairul Nizam Noh

This thesis presents an implementation of a current source full bridge parallel active filter for minimizing the input current distortion in a single phase system feeding a nonlinear load. In this work, the switching frequencies for active power filter are varied to observe the input current waveform and the total harmonic distortion. In this method, a current source active power filter is used to inject an equal but opposite current to mitigate the distortion of the input current. The input current after the mitigation process will be nearly shaped as a sinusoidal and in phase with the supply voltage. Unipolar pulse width modulation technique is used to generate the switching signal to control the insulated gate bipolar transistor (IGBT) in the proposed active power filter. From the simulation result, the input current waveform after the mitigation was nearly shaped as a sinusoidal and the total harmonic distortion values become smaller (less than 5%) when the switching frequencies were increased. In order to study the operation and the effectiveness of the rectifier circuit with the proposed active power filter in reducing the harmonic was simulated using Matlab/Simulink.