Research On Dynamic Wireless Power Transfer System For Electric Vehicle Based On Magnetically Coupled Resonance

The development of electric vehicle is the demand of green,sustainable and low-carbon economy.The power of electric vehicle comes from the battery.Non-contact wireless power transmission(WPT)is a safe,convenient and autonomous technology for electric vehicles and plug-in hybrid vehicles charging.And dynamic wireless power transmission technology is the key solution to electric vehicle's mileage short and high cost of battery.This paper presents a novel magnetically coupled resonant for electric vehicles based on distributed dynamic energy power supply system.The utilization of closed-loop control and fault protection leads to a higher power and efficiency.Comparative analysis of the WPT system based on different principles was accomplished.The resonant magnetic coupling topology was selected.Then the transmission mechanism modeling was analysed using two-port theory,coupled mode theory and the theory of mutual coupling.Afterwards,the performance parameters' s expression was derived and simulation analysis was done and the Serial-Parallel topology of transmission system is determined.Energy coupling device and dynamic power control circuit were designed with multi-parallel primary coils.After that,the characteristics of the system under different locations was analyzed.Then the power conversion circuits,the frequency and power control based on digital signal controller and PLL were designed.System's protection function was also done.Finally,the system modeling and simulation analysis were conducted.The built prototype system achieved the output power of 3.3kW,operating frequency of 125 kHz and the peak efficiency of over 90%.The results show that the system's performance meets all the design goals.The system's experiments were carried out on different transmission distance,different frequencies,different loads,different coupling angles and different dynamic positions.At last,the system output power and the overall efficiency were analysed through experimental data.