Power decoupling methods for single-phase three-poles AC/DC converters

This paper presents a new method for power decoupling of single phase AC/DC converters using the conventional PWM H-bridge converter for bi-directional AC/DC conversion at unity power factor, and a boost converter for the power decoupling function at DC side. The proposed method compensates the pulsating power at twice the grid frequency by absorbing the ripple current to a DC decoupling capacitor through the boost converter operation. This approach can eliminate the need of large filter capacitor in DC side which is required to suppress the low frequency ripples. This paper explains the principles of operations of the proposed method, and experimental results are also presented for validation.