基于磁耦合谐振的无线充电系统建模与分析

Modeling and analysis of wireless charging system based on magnetic coupling resonance

为了解决煤矿井下大量无线传感器节点电池更换难、维护难的问题,提出磁耦合谐振式井下无线充电理论模型.根据电路互感耦合理论,推导出谐振状态下接收功率和效率的计算方法,并依此研究传输距离、输入频率、负载大小对接收功率和效率的影响.结果表明:系统的最佳输入频率取决于4个线圈之间的距离.当输入频率为固有谐振频率,激励线圈和负载线圈之间的距离为52cm时,接收功率取得最大值2.74W,而激励线圈和负载线圈之间的距离为44cm时,效率取得最大值,可以达到81%.实验结果与理论分析、仿真结果的变化规律基本一致,可为实际应用提供参考.

In order to solve the problem of numerous wireless sensors batteries that is hard to be replaced timely, this paper proposes the model of wireless charging based on magnetic cou- pling resonance for coal mine. The calculation model for the received power and efficiency of the wireless charging system was given in resonant state by using mutual inductance coupling theory. This research investigated the influence of coupling coefficient, input frequency and the load on the received power and efficiency. The results show that the optimum input frequency of the system depends on the distance between the four coils. When the input frequency is the inherent resonance frequency and the distance between the excitation coil and load coil is 52 cm, the maximum of received power is 2.74 W the maximum of efficiency is 81% when the distance between the excitation coil and load coil is 44 cm. Experimental results are basically the same as the theoretical analysis and simulation results, which can provide a reference for practical application.