| The wireless charging technology of magnetic coupled resonant EV is a newly developing technology.The electromagnetic induction principle is used,which is combined with power electronics technology,magnetic coupling technology and control theory to achieve wireless power transmission.Compared with the traditional cable charging technology,it has the safe,convenient and achieving automatic control features.This thesis the double LCC compensation network is studied and Beiqi EV160 is as the charging object.The experimental platform is established and the constant current charging mode is adopted to realize the high power transmission.The constants mainly include as the following:Firstly,the study is from the theory of the magnetic coupled resonant wireless power transmission technology,including the theory of resonant circuit,mutual inductance model and four basic resonant circuits.The advantages and disadvantages of the four basic resonant circuits and their applications are compared and analyzed.Secondly,the hardware part of wireless power transmission technology is studied,including active power factor correction circuit,full bridge inverter circuit,magnetic coupler design and loss analysis.The parameters of active power factor correction circuit are designed.Matlab simulation and hardware circuit design are completed.The leakage magnetic field shielding and magnetic coupler loss are calculated by Ansoft Maxwell simulation optimization design.The entire wireless power transmission system device loss,coil loss and core loss are analyzed.Then,through the comparison and analysis of the resonant circuit,the composite double LCC compensation circuit is selected as the topology of the EV transmission circuit.The double LCC resonant compensation circuit is analyzed theoretically by Mathcad software,which includes the frequency characteristics of the input impedance,the characteristics of constant current \ constant voltage.The results is verified by Pspice.Finally,the experiment platform is established to test the system.The performance tastings include the horizontal,vertical,and rotational direction of the magnetic coupler.The output voltage of the active power factor correction,ripple voltage,and power factor are tested.The phase difference of the inverter voltage and current,the voltage and current of the coil are also tested.The module of the wireless charging is installed on the EV,replacing the original car charger.In alignment of primary and secondary coils,the wireless power transmission power and efficiency are tested.The whole transmission efficiency is up to 87%. |
