谐振式无线电能传输系统恒功率输出特性研究

在无线充电过程中，电池阻值的变化会引起输出功率的波动，从而减短电池寿命，影响充电安全。针对磁耦合谐振式无线电能传输变负载系统，通常是在接收端加入控制电路使输出功率稳定，但这增加了用电设备的体积。因此，文中提出了基于反射阻抗原理的两种恒功率控制策略： Sepic电路恒功率输出控制策略和移相控制恒功率输出控制策略。首先分析了负载电阻对输出功率的影响，然后推导了Sepic电路驱动信号的占空比、移相控制中驱动信号的移相角与输出功率的关系，给出了文中恒功率控制策略的原理。最后通过Matlab/Simulink搭建仿真模型，验证了文中理论分析及所提控制方法的正确性，仿真结果表明两种控制方式均能有效实现恒功率输出。

Constant power output characteristics of resonant wireless power transmission system

In the process of wireless charging, the fluctuation of output power is caused by the change of battery resistance, which shortens the battery life and affects the safety of charging. For the magnetic coupling resonance type wireless power transmission variable load system, usually a control circuit is added at the receiving end to stabilize the output power, but this increases the volume of the electrical equipment. Therefore, two constant power control strategies based on the principle of reflected impedance are proposed in the article: Sepic circuit constant power output control strategy and phase shift control constant power output control strategy. First, the influence of load resistance on the output power is analyzed, and then the relationship between the duty cycle of the driving signal of the Sepic circuit, the phase shift angle of the driving signal and the output power in the phase shift control is deduced, and the principle of the constant power control strategy in the article is given. Finally, a simulation model is built through Matlab/Simulink to verify the correctness of the theoretical analysis and the proposed control method. The simulation results show that both control methods can effectively achieve constant power output.