An Efficiency Improved Active Power Decoupling Circuit with Minimized Implementation Cost

Active power decoupling techniques are promising solutions for capacitance reduction in single-phase AC/DC or DC/AC systems. This paper proposes a novel circuit topology which can realize the power decoupling function without adding additional active switches into the circuit. Also, the proposed topology does not require additional passive component, e.g. inductors or film capacitors for ripple energy storage because this task can be accomplished by the dc-link capacitors themselves, and therefore its implementation cost can be minimized. Another unique feature of the proposed topology is that the current stress of power semiconductors can be reduced as compared to a conventional single-phase converter under high load operation. Therefore, the conversion efficiency can be improved and this is impossible for other existing active power decoupling circuits. The operational principle of the proposed circuit is discussed, and both simulation and experimental results are presented to show the effectiveness of the proposed circuit concept.