自激推挽式无线电能传输系统研究

Research on Wireless Power Transmission System Based on Self-excited Push-pull Oscillator

基于对推挽式自激振荡电路原理的详细分析,通过研究发射线圈电压电流的特性,建立了系统的等效电路模型,并采用理论计算和仿真分析验证了系统的性能。同时将自激推挽式无线电能传输系统应用于传感器节点的锂电池变距离无线充电中。最后搭建两线圈系统验证了自激推挽式无线电能传输系统具有频率自适应的能力;在一定范围内变耦合系数时能够输出稳定的功率并保持稳定的效率。当线圈间轴向距离在1~4 cm变化时,自激推挽式无线充电系统可为锂电池提供500 mA的稳定充电电流。

Based on the detailed analysis of the principle for a self-excited push-pull oscillation circuit,an equivalent circuit model of the system was established by studying the voltage and current characteristics of the transmitting coil.In addition,the system performance was verified by theoretical calculation and simulation analysis.Meanwhile,an self-excited push-pull wireless power transmission(WPT)system was applied to the variable-distance wireless charging of lithium batteries at sensor nodes.Finally,a 2-coil system was built to verify the system’s frequency self-adaption capability.This system can output stable power and maintain stable efficiency when the coupling coefficient was within a certain range.When the distance between coils varied from 1 to 4 cm,the self-excited push-pull wireless charging system can provide steady charging current of 500 mA for lithium battery.