Switch Mode Active Power Filter to Minimize the Effect of Harmonics through Current Detection

This paper presents a technique with instantaneous power theory in order to control APF under non-ideal mains voltage conditions. The quality of the electrical current becomes a major concern. Power electronic equipments draw non-sinusoidal currents from the utility, causing interference with adjacent sensitive loads and limit the utilization of the available electrical supply. In this paper a parallel active filter capable of reducing the total harmonic distortion in the supply for nonlinear loads is presented. The active filter used to compensate for the nonlinear load is a three-phase inverter. It is used to shape the line current to be in phase and of the same shape as the supply voltage. In this paper, the compensation techniques under unbalanced and distorted voltage conditions have been discussed. Performance of the proposed scheme has been found feasible and excellent under various non-ideal mains test conditions. Matlab/Simulink power system toolbox is used to simulate the proposed system. The simulation results are presented and discussed showing the effectiveness of the control algorithm.