三线圈无线输电系统的频率分裂特性和抑制方法

Frequency Splitting Characteristics and Suppression Method of Three-Coil Wireless Transmission System

首先以基尔霍夫定律为基础，分析三线圈WPT系统的S参数、传输效率以及该系统的频率分裂现象。频率分裂现象是线圈之间的过耦合导致系统出现不止一个谐振频率的现象。频率分裂仅出现在过耦合区域，由于在过耦合区域内阻与系统的输入阻抗不匹配导致频率分裂现象，本文提出一种阻抗匹配方法来抑制该现象。通过在发射端添加L型阻抗匹配网络并且在接收端组成概念性阻抗匹配网络，来实现抑制频率分裂现象、增大系统效率的目的。最后，通过实验和仿真来对比分析所提方法的正确性。

Based on the Kirchhoff law, the S-parameters, the transmission efficiency and the frequency division of the three-coil WPT system are analyzed. The phenomenon of frequency splitting is that the over-coupling between the coils causes the system to appear more than one resonant frequency. The frequency splitting occurs only in the over-coupled region. Since the internal impedance of the over-coupling region does not match the input impedance of the system, the frequency splitting phenomenon is proposed. Therefore, an impedance matching method is proposed to suppress the frequency splitting phenomenon. By adding an L-shaped impedance matching network at the transmitter and forming a conceptual impedance matching network at the receiving end, the purpose of suppressing the frequency splitting and increasing the efficiency of the system is realized. Finally, the correctness of the proposed method is compared by experiment and simulation.