磁谐振无线电能传输负载自适应阻抗匹配研究

针对磁谐振无线电能传输(MR-WPT)系统的负载改变时,现有阻抗匹配方法不能自动调节负载阻抗,导致系统电能传输效率降低的问题,提出了一种MR-WPT系统负载自适应阻抗匹配方法。为利用高频化提高MR-WPT系统的电能传输效率,选用E类功率放大器作为高频逆变电路。在磁谐振装置和负载之间加入DC/DC变换器,当负载阻抗变化时,通过调节DC/DC变换器的占空比将负载电阻变换到最大效率传输电阻,从而确保MR-WPT系统始终以最大效率工作。仿真和实验结果表明:所提出的阻抗匹配方法切实可行,能够优化MR-WPT系统的传输效率,输出功率为3.5 W时,传输效率达35%。

Research on load adaptive impedance matching of magnetic resonant wireless power transfer system

In view of problem that current impedance matching methods can’t automatically adjust load impedance of magnetic resonant wireless power transfer system(MR-WPT)when load changes,which leads to reduction of energy transfer efficiency of the system,a load adaptive impedance matching method of MR-WPT system was proposed.In order to improve power transmission efficiency of MR-WPT system by using high frequency,class E power amplifier is used as high frequency inverter circuit.A DC/DC converter is added between magnetic resonance device and load.When the load impedance changes,the load resistance is transformed to the maximum efficiency transmission resistance by adjusting the duty cycle of the DC/DC converter,thus ensuring that the MR-WPT system always works at maximum efficiency.The simulation and experimental results show that the proposed impedance matching method is feasible and can optimize transmission efficiency of MR-WPT system.When the output power is 3.5 W,the transmission efficiency reaches 35%.