基于E类功率放大器的四线圈中距离无线输电系统的优化设计

E类功率放大器由于具有拓扑简单、适用频率高、电能转换效率高等优点，是高频MHz级无线输电系统的理想电源。研究分析了四线圈无线输电系统的传输特性，提出传输效率的优化设计方法。同时，考虑到E类功率放大器的工作状态，提出通过激励线圈与发射线圈的距离调节，实现输入电阻的完美匹配，搭建了采用2.81 MHz的E类功率放大器的四线圈中距离无线输电系统。当传输距离为传输线圈边长的3.6倍时，系统电源端到负载端的整体电能传输效率为8.5%。

Optimization design of four-coil mid-range wireless power transfer based on E-class amplifier

The E-class power amplifier presents an ideal solution for high-frequency power supply applications, characterized by its simple topology, high operational frequency, and efficiency. This paper conducts a detailed analysis of the transfer characteristics of a four-coil wireless power transfer(WPT) system and proposes an optimal design method to achieve high transfer efficiency. Additionally, with considering the operating status of the E-class amplifier, perfect matching of input resistance is achieved by adjusting the distance between the driving coil and transmitting coil. A 2.81 MHz four-coil mid-range WPT system employing an E-class amplifier is established. At a transfer distance of 3.6 times the side length of the transfer coil, the overall transfer efficiency from the power source to the load reaches 8.5%.