基于电场耦合式的电动汽车无线充电技术电压优化方法

Voltage Optimization Method for Wireless Charging of Electric Vehicles Based on Capacitive Power Transfer

目前,基于电场耦合式无线电能传输是一种快速发展的技术,因其对比磁场耦合式无线电能传输技术更具经济性、可靠性与安全性,从而在多金属环境中得到广泛应用。由于电场耦合式无线电能传输系统利用高频电场传输电能,所以在耦合极板上存在非常高的高频电压,同时也会在诸如电动汽车表面等金属上感应出高电压,这将导致严重的安全问题。为解决上述安全问题,该文提出了基于电场耦合式的电动汽车无线充电技术优化方法来减小无线充电时车壳上的电压,并通过CLL补偿结构优化系统谐振。最后,设计并实现了车壳电压仅为3.88V,输出功率1.3kW,系统整体效率为87.7%的电场耦合式无线电能传输系统,验证了优化策略的可行性。

Capacitive power transfer is a rapidly developing technology.It is more economical,reliable,and safer than inductive power transfer,and can be widely used in environments that have many metal structures.Since capacitive power transfer uses high frequency electric field to transfer power,there are high frequency voltages stressed on coupled plates.Also,voltages will be induced on the surface of the applications such as electric vehicle,it is a serious problem for safety concern.To solve this problem,this paper proposes a static power transmission system optimization strategy based on capacitive power transfer system to reduce the voltage on the shell of a car.The CLL compensation structure is used and optimized to resonant system.A 1.3kW output power system with the optimization strategy is built to verify the analysis results.The efficiency of the prototype reaches 87.7%.With the optimization method,the effective voltage of the experiment shell is 3.88V which agrees with the calculation results.