磁耦合谐振式无线电能传输系统距离特性分析

Analysis of Distance Characteristics of Magnetically-Coupled Resonant Wireless Power Transfer System

在磁耦合共振系统中,相邻线圈之间距离的变化会影响传输性能。为了研究距离对系统传输性能的影响,建立了四线圈结构的磁耦合无线电能传输系统。基于互感耦合理论,得到了传输功率和效率与耦合系数之间的关系。在仿真分析和实验证据的验证下,发现耦合系数k_(23)(发射线圈和接收线圈之间)是影响传输效率的最显著因素。在最佳k_(23)下,传输效率会随着耦合系数k_(12)(源线圈与发射线圈之间)的增大而增大;随着耦合系数k_(34)(接收线圈与负载线圈之间)的增大,传输效率呈先增大后减小的趋势。同时推导了k_(12)、k_(23)、k_(34)的理论计算公式,为无线电能传输系统的参数优化和传递效率的提高提供了参考。

In a magnetically coupled resonance system,changes in the distance between adjacent coils can affect transmission performance.In order to explore the influence of distance on the transfer performance,a four-coil magnetically-coupled resonant wireless power transfer system is established.Based on the mutual inductance coupling theory,the relationship between the transfer power and efficiency and coupling coefficient is obtained.Supported by the simulation analysis and experimental evidences,it finds that the coupling coefficient k_(23)(between transmitter and receiver coils)is the most significant factor affecting the transfer efficiency.Under the optimal k_(23),the transfer efficiency will increase with the coupling coefficient k_(12)(between driver and transmitter coils).Besides,it will firstly increase and then decrease with the coupling coefficient k_(34)(between receiver and load coils).Moreover,the theoretical calculation formula of k_(12),k_(23) and k_(34) is deduced,which can make a contribution to the optimization of parameters and improvement of transfer efficiency for the wireless power transfer system.