Research On Wireless Charging Compensation Network For Electric Vehicle

The electric vehicle charging technology is an important part of the electric vehicle system,and it can be divided into two main forms,wired charging and wireless charging.Compared with wired charging layout,wireless charging is more flexible and safe,but the principle is relatively complex,and mature products are few.MOSt wireless charging technologies are still in research and development stage.The compensation circuit is the key component of the structure of the mainstream wireless charging system,which directly determines the charging performance and efficiency of the wireless charging system.In this paper,the typical compensation circuit topology in wireless charging system is deeply researched,and the performance of several compensation circuits is analyzed from theoretical,simulation and experimental aspects.The theoretical analysis of the topology of the typical compensation circuit is completed.The basic compensation circuit SS and two kinds of hybrid compensation circuits,LCC and CLC,are theoretically derived by the equivalent circuit method.The efficiency of three topological structures is calculated respectively,and the characteristics of constant pressure and constant current of different structures are compared.The simulation model of SS and LCC compensation circuit is set up,and the simulation research is carried out.Based on the LTSPICE simulation model,verified the working characteristics of two kinds of compensation circuit,a detailed analysis of the main electrical components of two kinds of compensation circuit in the process of work stress,and verified its soft switching characteristics in LCC circuit,the basis for the parameter selection and design of the hardware system.A test platform for SS and LCC compensation circuits is set up.Based on Ansys Maxwell finite element analysis,the design of the wireless charging coil is determined.The high voltage MOSFET is chosen to complete the design of the main circuit of the wireless charging inverter.According to the simulation results,two kinds of compensation circuit's hardware design and system function debugging are completed.The functional experiments and experimental results of SS and LCC compensation circuits are compared and analyzed.The efficiency and power transmission characteristics of the wireless charging system under SS and LCC compensation circuits are measured respectively.The experimental results show that the SS compensation circuit topology is simple,but the voltage stress of the devices,it is difficult to achieve high voltage applications,and can not achieve ZVS;LCC compensation circuit topology structure is relatively complex,compensation circuit parameter adjustment is relatively difficult,but low voltage stress,and can achieve ZVS.