Design And Experimentation Of High Frequency Power Source For Electrical Vehicle Wireless Charging System With DSP

Facing the pressure of energy-saving and emission-reduction,the electric car industry appears.Compared with wired power transfer technology,WPT technology is more secure,reliable,flexible and convenient with a future.The high frequency power supply designed in this thesis is to transform the power frequency alternating current into the required high frequency alternating current and its design directly affects the transmission performance of the system.According to the SAE J2954 standard,the WPT system is analyzed and the components of the high frequency power source with the design standards are clarified.Among different topologies,three phase bridge type uncontrolled rectifier circuit,Buck circuit and full bridge inverter circuit are selected as the main circuit of the high frequency power source.By discussing the control mode of the Buck circuit and the inverter circuit,the PWM is selected to control the Buck circuit,and the phase shift control is selected to control the inverter circuit which avoids the phenomenon of high frequency fever.The two control modes are closed loop regulation with PI and the working mode of the module is analyzed.The phase-shifting control strategy is carried out by Fourier transform and the relationship between the phase shifting angle and the output voltage is obtained.Based on theoretical analysis,this thesis selects the device of the main circuit and designs a control circuit board with sampling circuit and level conversion circuit.The program is designed with TMS320F28335 of DSP.The program includes the initialization part,the interruption and A/D conversion part,the ePWM pulse generation part,the effective value calculation method,the digital realization of PI,the FFT software filtering and the protection program.According to the selection and design of components,a high frequency power source model is built based on the simulation software PSCAD/EMTDC which prove the system is verified and realized.Finally,the experiment platform is built and the target function of the high frequency power source of the designed electric vehicle wireless power transfer system is realized.