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.