Design Of Inductively Coupled Power Transfer System For Electric Vehicle Based On Double LCC Compensation

Wireless power transfer technology is a new hot research field in power electronics industry.Compared with traditional wired power transmission,wireless charging has the advantages of convenience,safety,spark-free and electric shock hazard.It can be free from geographical and environmental constraints and greatly enhance flexibility.With the rise and popularization of electric vehicle industry,radio power transmission technology has gradually become the most promising hot research direction in the field of electric vehicle charging technology.Firstly,this paper introduces the implementation of radio power transmission technology and the current research status of the industry,and introduces in detail the widely used magnetic coupling induction radio power transmission system.By establishing the equivalent circuit model of loosely coupled transformer,comparing and analyzing the advantages and disadvantages of four common basic resonant topologies,and analyzing the system characteristics of a new type of high-order double LCC resonant network,based on the efficiency optimization of double LCC,a design method of resonant compensation capacitor parameters realized by soft-switching is proposed.Aiming at the problem of large leakage inductance and low coupling coefficient of loosely coupled transformer in wireless charging system,combined with the system characteristics of double LCC multi-compensation coil and the practical application conditions of electric vehicle,the system scheme of designing the core and coil structure of loosely coupled transformer is to integrate additional compensation inductance coil.Based on ANSYS Maxwell simulation sofrtware,the core and coil structure of loosely coupled planar transformer are simulated and analyzed.According to the design process,a loosely coupled transformer with high coupling coefficient and strong anti-offset ability is designed.Finally,the complete wireless charging system of electric vehicle is designed,including the main circuit parameter design of the system topology,system hardware circuit design and device selection,software control flow design and transformer winding.A 3.3kW dual LCC magnetic induction coupling electric vehicle wireless charging prototype is built to complete the load and coupling coefficient characteristic experiment and verify the system design.Feasibility of the scheme.Experiments show that the system works stably.Under rated conditions,the optimal transmission efficiency of the system is close to 96%,and under normal working conditions,the system maintains 94%of the high-efficiency power transmission.It is proved that the optimum design of soft switched capacitor parameters is reasonable and the research scheme of loosely coupled transformer is feasible,which accords with the conclusion of theoretical analysis.