Active shunt current shaping scheme for multiple paralleled DC-DC converters

A new shunt current shaping scheme for multiple paralleled dcdc converters is proposed in this paper. The current command for the shunt current shaper is indirectly obtained by forcing the source current to follow the demanded sinusoidal signal. The amplitude of the demanded sinusoidal source current that is in-phase with the source voltage can be determined from the sensed load currents of the post-stage dcdc converters. Neither high-order filters nor time-consuming computations are required. The shunt current shaper supplies all the harmonics and the out-of-phase fundamental of the distorted input current and the power source only supplies the in-phase fundamental component. Experimental results on a prototype system verify the feasibility of the presented scheme. The implemented shunt current shaper demonstrates an efficiency of 92% and a nearly unity power factor at the utility side. Copyright (C) 2011 John Wiley & Sons, Ltd.