LAUSR

ABSTRACT A new resonant converter for high-input voltage and high-output current applications is presented to realize the advantages of low turn-on switching losses, low reverse recovery losses, and low voltage stress of power semiconductors. The series-connected half-bridge converter is used to lessen the voltage stress of power switches at V in/2. Therefore, power switches with low voltage stress and low turn-on resistance can be used to reduce the conduction losses on the primary side. For high-output current applications, two transformers series-connected on the primary side and parallel-connected on the secondary side are used to automatically balance the load current so that the low current stress of fast recovery diodes can be used at the output side. The operated switching frequency is controlled to be less than the series resonant frequency of the resonant converter. Therefore, power switches can be turned on at zero-voltage switching and the rectifier diodes can be turned off at zero-current switching. Experimental verifications with a laboratory prototype are provided to demonstrate the performance of the proposed converter.