SiC MOSFET在双向无线充电应用中的开关性能及效率优化研究

Research on Switching Performance and Efficiency Optimization of SiC MOSFET in Bidirectional Wireless Charging Applications

SiC MOSFET器件具备开关频率高、损耗小、耐高温等特性,应用于无线充电中可以显著提升其功率密度及效率。但在无线充电变换器的控制中很容易出现硬开通、硬关断的情况,这会产生额外的开关损耗。同时,在电磁环境和寄生参数的影响下,开关管门级容易因电压过冲、振荡导致加速老化或损坏。基于上述原因对双向无线充电系统中的开关特性、开关损耗及影响开关可靠性的因素进行分析及仿真验证,最后通过对搭建的双向无线系统样机在满功率和半功率点进行不同驱动参数的对比实验,得出了驱动参数对系统传输效率及门级波形的变化趋势,对双向无线充电系统中SiC MOSFET的应用和效率优化具有一定参考依据。

SiC MOSFET devices have the characteristics of high switching frequency,low loss,and high temperature resistance,which can significantly improve the power density and efficiency when used in wireless charging.However,in the control of the wireless charging converter,hard turn-on and hard turn-off are easy to occur,which will generate additional switching losses.At the same time,under the influence of the electromagnetic environment and parasitic parameters,the gate stage of the switch tube is prone to accelerated aging or damage due to voltage overshoot and oscillation.Based on the above reasons,the switching characteristics,switching losses and factors affecting the reliability of the switch in the bidirectional wireless charging system were analyzed and verified by simulation.Finally,through the comparison experiment of different driving parameters at the full power and half power point of the built bidirectional wireless system prototype,the change trend of driving parameters on system transmission efficiency and gate-level waveform was obtained,which has a certain reference for the application and efficiency optimization of SiCMOSFET in bidirectional wireless charging system.