谐振与负载电流全解耦的零电压转换Buck电路

Zero-voltage Conversion Buck Circuit with Fully Decoupling Resonance and Load Current

针对Buck电路在高频状态下存在的开关损耗和高次谐波问题,提出了一种新型的Buck软开关拓扑结构。它在传统Buck电路的基础上添加辅助开关和串联谐振回路,利用辅助开关控制串联谐振回路实现主开关和辅助开关的零电压导通和关断,并在软开关过程中将谐振电流和负载电流完全解耦,减小了电路储能,降低了对谐振电感与电容的容量要求,使开关管的零电压导通更易实现。分析了新型Buck电路的工作原理,并根据谐振电感、电容与开关管通断时刻之间的关系计算出软开关电路的实现条件参数值,实验结果证明了该新型电路的有效性。

A new type of Buck soft-switching circuit was designed to solve the problems of switching loss and high-order harmonics when Buck circuit running at high frequency.The auxiliary switch and series resonant circuit were added on the basis of the traditional Buck circuit.The auxiliary switch was used to control the zero voltage switching of the main and auxiliary switches.In the soft switching process,the resonant current and the load current were completely decoupled,and the storage energy of the resonant circuit was reduced.The capacity requirement of resonant inductor and capacitor was reduced,and the zero voltage switching of the main switch was made easier.The principle of the new Buck circuit was analyzed.The realization condition parameters of the soft switching circuit were calculated according to the relationship between the resonant inductance,capacitance and the switching time of the switch device.The effectiveness of the new circuit was validated with experiment results.