基于宇称时间对称的P-SP拓扑无线电能传输系统特性分析

Characteristic analysis of P-SP topology wireless power transfer system based on parity-time-symmetric principle

宇称时间(PT)对称原理已经被验证可以作为提高无线电能传输系统自由度的有力工具,但基于PT对称的并联-并联(P-P)拓扑结构无线电能传输(WPT)系统的工作范围仍然受到限制。为解决这一问题,提出了一种基于PT对称原理的并联-串并联(P-SP)补偿WPT系统。通过等效电路法化简系统电路模型,并利用耦合模理论(CMT)分析电容分配比对振荡频率、临界耦合系数、满足系统进入PT对称区域的耦合系数和负载电阻值范围以及传输效率等工作性能的影响。构建样机开展实验,以检验所提方法的适用性,结果表明:可以在仅损失2%系统传输效率的情况下,将传输距离由110 mm扩大到210 mm,该操作可为扩大应用范围、增加应用场景、优化激光无线充电系统中发送模块单元和接收模块单元的工作性能做准备。

The parity time(PT)symmetry principle has been proved to be a powerful tool to improve the degree of freedom of wireless power transfer(WPT)systems.However,the operating range of the P-P(parallel-parallel)topology WPT system based on the PT symmetry principle is still limited.To solve this problem,a P-SP(seriesparallel)compensated WPT system based on PT symmetry principle is proposed.The circuit model of the system is simplified by the equivalent circuit method,and the influence of the capacitance distribution ratio on the oscillation frequency,the critical coupling coefficient,the coupling coefficient satisfying the system entering the PT symmetric region,the load resistance range and the transmission efficiency is analyzed by the coupled mode theory.A prototype is built to carry out experiments to test the applicability of the proposed method.The results show that the transmission distance can be expanded from 110 mm to 210 mm with only 2%loss of system transmission efficiency.Hence,preparations are made to expand the application scope,increase application scenarios,and optimize the working performance of the sending and receiving module units in the laser wireless charging system.