磁谐振式无线电能传输系统效率优化方法

Efficiency Optimization Method for Magnetic Resonance Wireless Power Transfer System

为提高无线电能传输系统输出控制的可靠性和电能传输效率,提出了一种基于扰动观测法和谐振式模块化多电平整流器的控制方法。研究了不同负载条件下整流器输入电压电流相位差对系统导通损耗和效率的影响规律,通过扰动整流器输入电压电流相位差动态调整原副边无功功率实现系统效率优化,并利用整流器最高电平占空比独立调整系统输出电压。研制实验样机验证了该方法的有效性。与固定整流器输入电压电流相位差相比,该方法全面提高了不同负载和输出电压下的系统效率,利用功率分析仪PW6001测得输出电压为44 V、输出功率为100 W时最高电能传输效率为97.3%。

To improve the reliability of output control and efficiency of power transfer by the Wireless Power Transfer(WPT)system,a control method based on perturbation and observation combined with resonant modular multilevel rectifier is proposed.The influence of the phase difference between the rectifier input voltage and current on the conduction loss and efficiency of the WPT system under different load conditions is obtained based on the analysis of the relationship among the voltage gain of the series-series compensated WPT system and the duty cycle of the rectifier,as well as the relationship between the phase difference and load resistance.The proposed efficiency optimization method disturbs the phase difference between the input voltage and current of the rectifier to dynamically adjust the reactive power in the primary and secondary side,and adopts the rectifier duty cycle to adjust the system output voltage.An experimental prototype is developed to verify the effectiveness of the method.Compared with the fixed phase difference between the input voltage and current of the rectifier,this method comprehensively improves the system efficiency with different loads and output voltages,and the maximum power transfer efficiency measured by the power analyzer PW6001 is 97.3%when the output voltage is 44 V and the output power is 100 W.