磁谐振无线电能传输串并式模型频率分裂研究

Study on Series-Parallel Model's Frequency Splitting of Wireless Power Transmission System via Magnetic Resonance

等效负载与线圈间距的改变,会导致磁谐振无线电能传输(WPT)系统出现谐振频率分裂,严重影响其传输效率.针对两线圈磁谐振WPT系统的串并(SP)式模型,基于等效电路理论,推导出了电流有效值表达式,采用Matlab仿真分析了等效负载、线圈间距改变时的谐振频率分裂现象.结果表明:磁谐振WPT系统的谐振频率与等效负载及线圈间距密切相关,等效负载大于某阈值或者线圈间距小于某阈值时均会导致谐振频率漂移并出现频率分裂;并且相对于等效负载,系统谐振频率的漂移对线圈间距变化更为敏感.

The variation of equivalent load and distance between the coi ls will lead to a resonance frequency splitting of Wireless Power Transmission （WPT） system via magnetic resonance, which will affect the transmission efficiency of the WPT system seriously. An expression of current ef-fective value is deduced based on the equivalent circuit theory for series parallel model of WPT system with two coils,and the phenomenon of resonance frequency splitting with the variations of equivalent load and distance between the coils is simulated and analyzed by using Matlab. The re-sults show that the resonant frequency of WPT system is closely related to the equivalent load and the distance between coils,that is,it will cause the drifting of resonant frequency and a reso-nance frequency splitting when the value of equivalent load is higher than a threshold or the dis-tance between coils is less than a threshold,and the drifting of resonant frequency is easily affect-ed by the distance between coils comparing with the equivalent load.