无线电能传输系统的频率跟踪技术与控制方法

Frequency tracking and controlling of wireless power transfer system

针对无线电能传输系统因受到各种因素影响而产生的频率失谐问题,通过系统耦合电路分析,得出系统失谐对接收功率和传输效率的影响规律,在此基础上提出一种基于最大接收电压的频率跟踪控制方法。该方法实时检测接收端负载电压,根据电压的反馈信息自动调整发射源的频率,以确保系统始终处于最大功率传输状态,提高了系统的接收功率和传输效率。设计控制电路并编写控制程序,实现了对频率的精确控制。最后,搭建相应电路实验平台,在传输距离、负载阻值和线圈偏移量改变的工况下,分别进行开环频率实验和频率跟踪实验。实验结果表明,采用频率跟踪控制的无线电能传输系统,其接收功率和传输效率都明显高于固定频率下的系统,验证了提出控制方法的有效性。

To address the frequency detuning issue of a wireless power transfer system from different aspects,the variation characteristics of the transmitted power and efficiency of the system due to the detuning were investigated based on the coupling circuit model of the system,and a frequency tracking and updating methodology based on the maximum received voltage was proposed.From the monitored variation of the load voltage at the receiving end,the source exciting frequency was constantly updated to ensure that the system is always in the maximum power transmission state,improving the transmitting power and efficiency of the system.The control circuit was then designed and the control software was developed to realize a precise control of frequency.A wireless power transfer prototype was constructed,the corresponding experimental studies without and with the proposed frequency tracking and updating methodology were conducted respectively in different working conditions including variations in transmission distance,load resistance and coil offset.The experimental results show that the received power and transmission efficiency of the wireless power transfer prototype using the proposed frequency tracking and updating are higher than those of the same system without the proposed frequency tracking and updating methodology,others being equal,verifying effectiveness of the proposed methodology.