考虑线圈偏移的无线充电系统恒流/恒压输出研究

Research on constant current/constant voltage output of wireless charging system under coil misalignments

在感应式电能传输(IPT)汽车应用中,由于线圈对不准而导致线圈自感、互感参数发生变化是不可避免的,最终会导致系统输出偏离恒定值、系统效率下降。针对上述现象,本文提出一种考虑线圈偏移的IPT系统恒流(CC)/恒压(CV)输出方法。针对线圈自感变化导致的补偿网络失谐现象,通过调节全桥逆变器的开关频率使系统始终工作在谐振状态,逆变器输出满足零相角(ZPA),效率提高;针对线圈互感变化导致的输出变化问题,通过全桥逆变器的移相调节使整流器输出维持在恒定值,即CC或CV。最后,搭建一套输出为96V/2A的实验样机验证理论的正确性。实验结果表明,IPT系统最高效率可达95.3%。

Due to the coil misalignment,the variation of self-inductance and mutual inductance of coils are inevitable in electric vehicles(EVs)applications based on inductive power transfer(IPT)technologies,which will eventually lead to the deviation of the system output from the desired value and the decrease of efficiency.In view of the mentioned phenomenon,a control method for constant current(CC)or constant voltage(CV)output is proposed under coil misalignments.Considering the detuning phenomenon caused by the variation of self-inductance,the resonant state can be maintained by shifting the switching frequency of the full-bridge inverter,thus zero phase angle(ZPA)and high efficiency can be realized.Then,the CC or CV output can be implemented by adjusting the phase-shift angle when the mutual-inductance varies.A 96V/2A experimental prototype is built to verify the correctness of the theoretical analysis.The maximum efficiency of the IPT system can reach 95.3%.