具有恒功率恒效率输出特性的三线圈WPT系统

Three-coil Wireless Power Transfer System With Constant Output Power and Constant Transfer Efficiency Characteristics

含中继线圈的无线电能传输(wireless power transfer,WPT)技术是提高系统传输距离的有效解决方案。基于宇称时间(parity time,PT)对称原理,含中继线圈的多线圈WPT系统在传输距离变化时具有恒功率恒效率的输出特性。已有的多线圈PT对称系统工作时需要满足相邻线圈之间距离相等条件,限制多线圈PT对称系统的实用性。为此,该文提出一种发射端含可变参数的三线圈PT对称WPT系统,当系统不满足距离相等条件时,通过调节可变电感及可变电容使系统满足PT对称条件。该文推导系统的输出特性表达式,论述可变参数的构造、控制方法,并搭建所提系统的实验平台。实验结果表明,相较于已有系统,所提系统在不满足距离相等条件时,具有恒功率恒效率的输出特性。

The wireless power transfer(WPT)technology with relay coils is an effective solution to increase the transmission distance of the system.Based on the parity time(PT)symmetric principle,a WPT system with relay coils can maintain constant output power and constant transfer efficiency when the transmission distance changes.However,in the existing system,the condition of equal distance between adjacent coils must be satisfied,which greatly limits the practicability of the system.Therefore,this paper proposed a three-coil PT symmetric WPT system with variable parameters in the transmitting coil.When the system failed to satisfy the equal distance condition,the values of the variable inductor and capacitor were adjusted to meet the PT symmetric conditions.The paper firstly deduced the output characteristic of the system,then discussed the construction and control method of variable parameters,and finally built an experimental platform for the proposed system.The experimental results show that compared with the existing system,the proposed system could maintain constant power and transfer efficiency when the equal distance condition is not satisfied.