An improved active filter for distorted voltage conditions

The increasing use of power electronic system has led voltage harmonic distortion level to an unacceptable level at point of common coupling (PCC). Most of the modern solutions of eliminating load current harmonics by using active filter is based on sinusoidal source voltage. However, the voltage at PCC is not purely sinusoisdal. This paper proposes a shunt active filter (SAF) based on instantaneous active and reactive power theory which can mitigate the load harmonics properly even if the source voltage is distorted. Space vector PWM based voltage source inverter is used in current control mode to filter out current harmonics. PI controllers are used for the current controller to get desired dynamic response. The proposed algorithm is verified through simulation. Real life conditions are considered in the simulation and the simulation results are presented.