Abstract：Introducing a resonant inductor and two clamping diodes into the full bridge converter can widen the load range of zero-voltage-switching (ZVS) and eliminate the voltage spike across the rectifier diodes. The resonant inductor is short-circuited and its current keeps constant when the clamping diode conducts under heavy-load condition, resulting in larger conduction losses in the power switches and clamping diodes. Furthermore, the clamping diodes are turned off hard when the load current is reduced to a certain degree, leading to serious reverse recovery loss or even failure of the clamping diodes. In this paper, the operation principle of the full bridge converter with clamping diodes under light-load condition is analyzed in detail and three kinds of clamping diode current resetting schemes are presented, in the meanwhile, the pros and cons of several existing clamping diode current resetting circuits are compared and a novel ZVS PWM full bridge converter employing auxiliary transformer to reset clamping diode current is proposed. With the introduced auxiliary transformer, the clamping diode current can be decayed rapidly over the whole load range, thus not only the conduction losses can be reduced and the conversion efficiency can be increased, but also the hard turn-off of the clamping diodes can be avoided. The operation principle of the novel ZVS PWM full bridge converter with auxiliary transformer is analyzed and the design of the auxiliary transformer is discussed in this paper, and experimental results verify the effectiveness of the proposed full bridge converter.
陈武, 阮新波, 陈乾宏, 葛俊吉. ZVS PWM全桥变换器中钳位二极管电流复位方法研究[J]. 电工技术学报, 2011, 26(8): 33-43.
Chen Wu, Ruan Xinbo, Chen Qianhong, Ge Junji. Research on Clamping Diode Current Resetting Scheme of ZVS PWM Full Bridge Converter. Transactions of China Electrotechnical Society, 2011, 26(8): 33-43.
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2011, Vol. 26 
