Active Power Filter Implementation Using a Four Leg VSI for Renewable Power Generation Systems

Renewable generation affects power quality due to its nonlinearity, since solar generation plants and wind power generators must be connected to the grid through high-power static PWM converters. The harmonics produced by the non-linear loads at the point of common coupling deteriorate the power quality. The effective method to mitigate the harmonics is the implementation of the active power filter with a four-leg voltage-source inverter using a predictive control scheme. 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 which are based on the equivalent linear model. An active power filter implemented with the four-leg VSI using a novel predictive scheme is presented in this paper. Under steady state and transient operating conditions the compensation performance of the active power filter is demonstrated using MATLAB/SIMULINK. The results show the predictive method controls very effectively the load and performs very well compared with that of the classical solutions.