Active DC-link power filter for single phase PWM rectifiers

Single-phase PWM rectifier produces second order ripple power and voltage pulsation on DC side, which is harmful to both the grid and load. The pulsating power is usually absorbed by a bulky capacitor bank and/or a dedicative LC resonant link, which results in low power density. An alternative way to do this is using some active filter circuit to direct the pulsating power to an energy storage component. As a result, the main DC link capacitor can be reduced substantially. Based on a comparison of DC-link active power filter (APF) schemes, this paper chooses a simple but effective half-bridge topology, and proposed a control strategy based on dual-loop deadbeat control plus repetitive control. This topology with the proposed control strategy can effectively reduce the voltage pulsation on DC bus and improve the power density of the rectifier.