Series resonant converter with series-parallel transformers for high input voltage applications

A new zero voltage switching (ZVS) converter with the series half-bridge legs for high DC bus application is presented in this paper. Two circuit modules with the interleaved pulsewidth modulation (PWM) are adopted to share the load current. In each circuit module, a series resonant converter with two transformers that are series-connected in primary side and parallel-connected in secondary side is used to achieve load current sharing and reduce the current stresses of rectified diodes and transformer secondary windings. Based on the series resonant behavior, power MOSFETs are turned on at ZVS and rectifier diodes can be turned off at zero current switching (ZCS). Two half-bridge legs and two split capacitors are connected in series such that the voltage stress of each active switch is clamped to one-half of DC bus voltage. Experiments with a laboratory prototype with 24V/40A output are provided to verify the effectiveness of the proposed converter.