基于铁氧体反射器的磁谐振无线能量传输效率的优化

Efficiency improvement of magnetic resonant wireless power transfer system based on ferrite reflector

为了改善磁耦合无线能量传输系统的传输效率随距离增加而快速衰减问题,提出一种基于铁氧体结构的优化设计方案.将四谐振体无线能量传输系统等效为二端口网络,分析推导了系统传输效率的表达式.仿真并设计制作了收发线圈直径为30cm的磁耦合无线能量传输系统,实测在30cm传输距离内传输效率达90%以上,在60cm处传输效率约40%,测试结果与仿真结果相吻合.在此基础上,保持原始系统的结构参数不变,引入基于铁氧体结构的磁反射面.研究了两种不同面积大小的磁反射面对系统传输效率的影响,发现不同面积的磁反射面对系统的传输效率有积极和消极两种影响.通过对铁氧体结构的优化设计,实现在30cm到90cm的传输距离内,相比原始系统传输效率最大有15%的提升.

A ferrite reflector-based optimization design of magnetic resonant wireless power transfer （WPT） system to improve transmission efficiency is proposed. The WPT system composed of four re- sonators is considered as a two-port network to deduce the transfer efficiency. Then a magnetic resonant WPT system whose receiving and transmitting coils have a diameter of 30era is designed and manufac tured. The measured transmission efficiency is above 90% at the distance of 30cm while decreases to a- bout 40% when the distance increases to 60era. Measured results are in good agreements with simulated ones. Based on this WPT system, two different ferrite reflectors are introduced to improve the transmis- sion efficiency. Results show that the different size of magnetic reflectors may have positive or negative effects on transmission efficiency. By optimizing the ferrite reflector, the maximum 15 % improvement of transmission efficiency is obtained at the distance range of 30cm to 90cm.