【摘要】 为提高同步整流Buck变换器效率,此处研究了零电压开关(ZVS)软开关技术。提出了基于瞬间电流建立的ZVS软开关方法,在主开关管开通前产生一个瞬间电流脉冲,该电流脉冲将流过主开关管的反并联二极管,产生ZVS开通环境,实现主开关管ZVS软开关。所提ZVS软开关方法可实现同步整流Buck变换器的全负载范围ZVS软开关且辅助电流带来的导通损耗较小。此处详细分析了所提Buck变换器的工作过程,设计了电路参数,最后在450 W同步整流Buck变换器样机中验证了软开关方法的正确性。更多还原

【Abstract】 To improve the efficiency of the synchronous rectifier Buck converter,the zero-voltage switching(ZVS) soft switching technology is studied.A ZVS soft switching method based on transient current build-up technique is proposed.A transient current is generated before the main switch is turned on and this current will flow through the antiparallel diode of the main switch to generate a ZVS turn on condition,thus the ZVS soft switching of the main switch will be realized.The proposed ZVS method can achieve the full load range ZVS soft switching of the synchronous rectifier Buck converter,and the conduction loss caused by the auxiliary current is small.The working process of the proposed Buck converter is analyzed in detail and the main circuit parameters are designed.Finally,the correctness of the proposed ZVS method is verified based on a 450 W synchronous rectifier Buck converter prototype.更多还原