谐振式电动汽车无线充电系统频率分裂抑制方法

Method of Preventing Frequency Splitting in Resonant Wireless Charging System for Electric Vehicle

谐振式电动汽车无线充电系统在充电过程中由于参数变化出现频率分裂现象,而产生多个谐振频率,导致系统在原谐振频率处的输出功率降低。以互感模型为基础推导得出频率分裂与负载阻值和耦合系数有关,建立阻抗角模型得到无线充电系统在负载阻值越小,耦合系数越大时越容易出现频率分裂的结论。进而提出一种使用buck变换器调节负载阻值的方法,通过抑制频率分裂而提升系统的输出功率和传输效率,MATLAB仿真验证了方法的有效性,为无线充电系统抑制频率分裂和提升输出功率提供了有效措施。

In the resonant wireless charging system for electric vehicles,frequency splitting occurs due to parameter changes during the charging process,and multiple resonant frequencies are generated,resulting in a decrease in the output power of the system at the original resonant frequency.Based on the mutual inductance model,it was concluded that the frequency splitting was related to the load resistance and the coupling coefficient.The establishment of the impedance angle model showed that the wireless charging system was more likely to have frequency splitting when the load resistance was smaller and the coupling coefficient is larger.Furthermore,a method of using buck converter to adjust the load resistance was proposed,which improveed the output power and transmission efficiency of the system by suppressing frequency splitting.MATLAB simulation verifies the validity of the method,which provides effective measures for preventing frequency splitting and improving the output power for the wireless charging system.