Analysis, design and implementation of ZVS converter with series connected transformers

This paper presents the system analysis, design consideration and implementation of a Zero Voltage Switching (ZVS) DC-DC converter with series connected transformers. The buck-type converter with active snubber circuit is proposed in order to limit voltage stress on power switch and to achieve ZVS turn-on. The ZVS turn-on of switches is implemented in the transition interval of two complementary switches such that the switching losses and thermal stresses on semiconductors are reduced. The current doubler rectifier is adopted at transformer secondary side in order to achieve partially ripple current cancellation. Therefore, the current ripple on output capacitor is decreased and the size of output choke and output capacitor are reduced. Experimental results for a 400W (12V/34A) prototype were presented to verify the effectiveness of the proposed converter.