An Active Power Filter Implemented with a 4-Leg VSI Using Predictive Control Scheme for Improving Power Quality

The non- linear loads are connected at the point of common coupling generates the harmonics, which may deteriorate the power quality. The active power filter has been proved to be an effective method to mitigate harmonic currents generated by the non-linear loads as well as to compensate reactive power. The methods of harmonic current compensation play a crucial part in the performance of active power filter. Traditionally, active power filters have been controlled using pre-tuned controllers, such as PI-type or adaptive, for the control of current as well as the dc-voltage loops. PI controllers must be designed based on the equivalent linear model. Predictive controllers use the nonlinear model, which is closer to real operating conditions in order to improve the performance and life of the power switches of voltage source inverter (VSI), reduces its switching frequency. An active power filter implemented with a 4-leg voltage source inverter using a predictive control scheme is presented in this paper. Predictive current control algorithm is based on the system model. The compensation performance of the proposed active power filter and the associated control scheme under steady state and transient operating conditions is demonstrated through simulations using MATLAB/SIMULINK.