采用耦合电感的ZVZCS PWM三电平直流变换器

ZVZCS PWM Three-level DC Converter with Coupled Inductor

提出了一种零电压零电流软开关(ZeroVoltageZeroCurrentSwitching,简称ZVZCS)PWM三电平直流变换器。它的主开关管电压应力是输入电压的1/2。耦合电感取代了常规滤波电感,它所感应出的电压由功率变压器反射回初级,使得变换器在零状态时的循环电流减小直至零,以实现内管的零电流关断。通过改变耦合线圈的匝比,可任意设置用于电流回零的电压幅值的大小,以调节电流回零的时间。详细介绍了电路的工作原理、各状态的等效电路及其约束方程;给出了主要的电压、电流波形。仿真和400W实验结果验证了该电路的正确性。

A novel zero-voltage and zero-current-switching （ZVZCS） three-level DC/DC converter is presented in this paper.ln this converter,the voltage applied to the power switches is only the half of the DC input bus voltage.Through introducing a coupled inductor replacing the common output inductor,the induced voltage of the coupled inductor in the second side is reflected to the primary side of power transformer and is used to reset the circulating current at the zero state. Zero current switching for the inner switch can be realized. On the other hand, by regulating the winding ratio of the coupled inductor,the voltage,which is used to reset the primary current,can be easy adjusted.The analysis of operation principle of the converter is presented in the paper,Pspice simulation and experimental results are given to verify the validity of the converter.