Efficiency Optimization Research On Wireless Power Transfer System Applying SiC MOSFET

Wireless Power Transfer(WPT)technology,compared with traditional charging technology has a difference that transfer the power from the primary side to the secondary side through electromagnetic field without using power cable.There are lots of studies about the efficiency of the WPT system,however these studies mainly focus on the peak efficiency of the system,the studies about the efficiency of the system during the whole charging period are still not enough.An aspect of WPT system efficiency improvement is the usage of wide bandgap semiconductor.However,with the widely application of SiC MOSFET,the voltage and current spikes,ringing during the switching transient and serious EMI problems also come with the high switching speed of the SiC MOSFET devices,and these issues can not be ignored.In this thesis,a wireless charging system applying SiC.devices hardware design is completed;the voltage and current spikes,ringing during the switching transient issues are analyzed and suppressed;with considering the characteristics of SiC MOSFET and existed driving methods,a SiC MOSFET driving method applying IC chips is proposed.Analyze the theoretical efficiency of LCC-S compensation network and hardware loss of the designed wireless charging system in detail;based on the analysis,apply the existed Time Weighted Average Efficiency conception,optimize the LCC-S compensation network with considering the maximum efficiency during the whole charging period;finally verify the study and analysis in the thesis through software simulation.