Research On Magnetic Coupling Resonant Wireless Charging System Primary Control Strategy For Electric Vehicles

Environmental pollution and energy depletion are becoming more and more serious.The world is vigorously developing electric vehicles to replace traditional energy vehicles.However,the problem of endurance caused by charging becomes the main bottleneck of the popularity of EVs.Compared to the traditional wired charging of electric vehicles,as an emerging technology,wireless power transfer(WPT)technology is attracting wide attention due to its advantages of flexibility convenience,safety and small occupied space.Based on the magnetic coupling resonance technology and power electronics technology,the research work in this paper mainly consists of following parts:The configuration and characteristics of magnetic coupling resonant wireless charging system is studied and analyzed.And the double-sided LCC resonant compensation network is proposed based on the traditional basic compensation network,compared with transmission power,component stress,transmission efficiency by simulation verification and practical application,it is determined that double-sided LCC resonant compensation topology is applied to the wireless charging system for EVs.In this paper,the double-sided LCC magnetic coupling resonant wireless charging system mainly comprises three parts:the first part put forward a parallel single-phase low ripple power factor correction circuit.The control chip of this circuit is UCC28070.The main function of this circuit is to convert 220 VAC power to 356 VDC by EMI filtering,rectification and boosting.The second part includes Pulse Width Modulation(PWM)full-bridge inverter DC/AC module,resonant compensation network,transmitting coil,receiving coil and rectifier.This part mainly achieves wireless power transmission.The equivalent circuit is analyzed to obtain a dead time calculation method,so that the inverter realizes soft switching.The third part is to estimate the relationship between the output parameters of the equivalent circuit and the output voltage and current of the primary inverter.It can be deduced that the output voltage and current of the system can be controlled by adjusting the phase shift angle of the inverter drive signal,so that the constant current/voltage of the PI-based phase-shifted full-bridge inverter circuit can be realized under the condition of weak communication between the primary and secondary sides.Based on the above theoretical analysis,the software and hardware circuit is designed,and the experimental platform of the double-sided LCC magnetic coupling resonant wireless charging system for electric vehicles is built.The input voltage is 220 VAC,the transmission gap is 100 mm,and the coil is positively transmitted with power 3.3k W from the grid to the load.The highest efficiency of 88% for wireless power transmission demonstrates the feasibility and stability of the wireless charging system designed in this paper.