DC/DC converter with parallel input and parallel output with shared power switches and rectifier diodes

Abstract

A DC/DC converter with parallel input and parallel output circuit topology is presented to achieve the main features of reduced switch count and medium power level compared with conventional parallel half-bridge resonant converter. The proposed converter has three resonant circuits to share load currents and reduce the current stress of circuit components. These three resonant circuits use the same power switches to deliver power from input side to output load so that the switch counts are reduced compared with the conventional parallel resonant converter. The rectifier diodes at the secondary side of three resonant circuits are partially used in common so that the diode counts are also reduced. Since three resonant circuits are connected in parallel, the sizes of the transformers and active and passive components are reduced. The switching frequency of the proposed converter is operated to be less than the series resonant frequency. Thus, active switches are turned on under zero voltage switching and rectifier diodes are turned off under zero current switching. A 1.6 kW laboratory prototype is designed and constructed to demonstrate the feasibility and performance of the proposed circuit.