Implementation of a series resonant converter with series-parallel connection

This paper presents a new series resonant converter to deal with high input voltage applications. Two half-bridge converter legs connected in series and two split capacitors are adopted in the proposed circuit such that the voltage stress of each active switch is clamped to half of input voltage. Thus power MOSFET with 600V voltage stress can be used in the proposed circuit when input DC bus voltage is less than 1200V. For high output current applications, two transformers with series-connected in primary side are adopted to ensure the balanced secondary winding currents and to share the load current. Thus low current stress of fast recovery diode can be used at the secondary side. Based on the series resonant behavior, the MOSFETs are turned on at zero voltage switching (ZVS) and the rectifier diodes are turned off at zero current switching (ZCS) such that the switching losses on power semiconductors are reduced. Finally, experiments with a laboratory prototype (48V/1000W) were provided to verify the effectiveness of the proposed converter.