A feed-forward control strategy is proposed for active power filter. The feed-forward controller and the current controller are designed based on the state-space averaging model and the voltage controller is designed based on the power model. Since the grid voltage may generate big impulsive current during system startup, the feed-forward controller reduces effectively the effect of perturbing grid voltage and DC voltage on controlled current to improve the dynamic performance of system. The reference current for grid current control is directly obtained from the DC voltage control loop, which...