副边自动切换充电模式的电动汽车无线充电系统设计

Design of Electric Vehicle Wireless Charging System with Automatic Charging Mode Alteration at Secondary Side

在电动汽车无线充电的过程中,恒流模式需要快速、稳定地切换到恒压模式以保障电池和电动汽车的安全,这往往需要原、副边之间的通信及原边复杂控制方法的介入。文中提出了一种免去原、副边之间的通信,且不需要原边提供控制手段,仅在副边自动切换谐振补偿网络即可完成恒流充电模式向恒压充电模式的快速切换的方法,同时提出了副边谐振补偿网络参数的设计方法,保证了切换过程中电池充电电压的稳定性。以LCC-LCC向LCC-S谐振补偿网络切换为例,对所提出的设计方法进行了分析和验证。实验表明,应用所提出的方法,输出的电流和电压随着电池等效负载的改变而保持恒定,且切换过程平滑稳定,结果满足电动汽车充电的要求。

In the process of wireless charging for electric vehicles,the constant current（CC）mode must be changed to constant voltage（CV）mode immediately and smoothly in order to ensure the safety of batteries,which always needs wireless communication between the primary side and the secondary side and complex control methods at the primary side.This paper proposed a method automatically and rapidly changed between the CC mode and the CV mode by changing the resonant compensation network at the secondary side without communication and complex control process.Additionally,a method for designing the parameters at the secondary side is proposed to ensure the stability of the battery voltage at the changing moment.By an example of changing from LCC-LCC to LCC-S resonant compensation network,the proposed design methods are analyzed and verified.The experiment results show that the output current and voltage with the change of load are almost constant by using the proposed methods,and the process of changing from the CC mode to the CV mode is stable,which meet the charging requirement of electric vehicle.