Design And Implementation Of High Frequency Power Supply Based SiC MOSFET Used In Wireless Power Transfer

Since 2007 MIT proposed magnetic resonance coupled wireless power transfer(WPT)technology,the world set off a study of WPT technology boom.The WPT technology applied in EV,as an important way to add the existing EV charging method with safe,convenient,easy maintenance,and many other advantages,and the WPT will be extremely promising in future.The thesis first describes the background and development of WPT technology for EV,and clarifies the significance of studying WPT high frequency power supply.The thesis selects the new SiC device as the core component of the high frequency power supply,as an application in the new technology exploration.The thesis introduces the basic structure of EV WPT system,and regards the coupling resonant coils and their compensation networks,vehicle power electronic device and vehicle battery system as the load of the high frequency power supply.Based on this point,the load characteristics are analyzed,and a simplified model of coupled resonant coils and vehicle battery is proposed.Then the author designs the index of high frequency power supply according to load demand.The thesis introduces the topologies of several high frequency inverters commonly used in WPT research.By comparing the characteristic indexes of each topology,the full bridge structure is chosen as the topology of the prototype.In the thesis,the operating frequency and power control of WPT system are clarified.As the operating frequency is high,we must carefully consider how to control the switches.By comparing the basic principles of pulse width modulation(PWM)and phase shift modulation(PSM),the phase shift modulation technique which is more suitable for high frequency condition operating is selected.By the most basic theoretical analysis,the thesis gives the operation modes of the selected topology as the basis of simulation and experiment.The thesis completes the circuit topology of high frequency power supply and detailed theoretical calculation,and taking into account the follow-up high-power experiments,in the selection of components reserved for the margin,the design of high-frequency power supply output rated power 4.6kW,the rating voltage of 460V,the rating frequency of 85 kHz.In the thesis,according to the charging characteristics of the vehicle battery,respectively,for the high-frequency power supply constant current output and constant voltage output of the two modes,and accordingly gives the algorithm flow,the preparation of the software.According to the parameters of the selected components,the MATLAB/Simulink simulation circuit is built and the simulation results are discussed under several different load conditions.Finally,the setup and experiment process of the prototype are introduced.A lot of tests are made for each sub-module and system.The function of WPT high frequency power supply is verified by cascaded magnetically coupled resonant coil and bulb load.