The parity-time (PT) symmetric magnetic coupling wireless power transfer (MC-WPT) system has received a great deal of attention since it was proposed. Its transmission efficiency has been greatly improved when compared with previous research. The operational amplifier (OA) is a typical construction method for PT symmetric MC-WPT systems. On this basis, to achieve a higher transmission efficiency and a longer effective power transmission distance at the same time, this paper constructs an OA-based tri-coil PT symmetric MC-WPT system. The analytical expressions of its singularity, PT symmetric state, and PT symmetric broken state are obtained. Then a complete set of parameter design criteria for the tri-coil PT symmetric system is derived. The transmission efficiency and resonant frequency of two-coil and tri-coil system are simulated on MATLAB software, and the simulation results are consistent with the theoretical analysis results. Finally, an experimental device is constructed to further verify the correctness of the theory. This paper demonstrates that the effective power transmission distance of the tri-coil PT symmetric MC-WPT system is more than twice that of the two-coil PT symmetric MC-WPT system, which can achieve a good balance between transmission efficiency and transmission distance.

奇偶时间（PT）对称磁耦合无线电力传输（MC-WPT）系统自提出以来就受到了极大的关注。与以往的研究相比，其传输效率有了很大的提高。运算放大器（OA）是PT对称MC-WPT系统的典型构造方法。在此基础上，为了同时实现更高的传输效率和更远的有效电力传输距离，本文构建了基于OA的三线圈PT对称MC-WPT系统。得到了其奇点、PT对称态、PT对称破断态的解析表达式。然后导出了一套完整的三线圈 PT 对称系统参数设计准则。在MATLAB软件上对双线圈和三线圈系统的传输效率和谐振频率进行了仿真，仿真结果与理论分析结果一致。最后搭建实验装置进一步验证理论的正确性。本文论证了三线圈PT对称MC-WPT系统的有效电力传输距离是双线圈PT对称MC-WPT系统的两倍以上，可以在传输效率和传输距离之间取得很好的平衡。