磁耦合回路激励源频率与阻抗角关系研究

Study on the relationship between excitation source frequency and impedance angle of magnetic coupling loop

为了探究电动汽车无线充电频率跟踪式调谐系统,首先通过构建磁耦合回路模型研究了其激励源频率与其阻抗角之间的定量关系。发现当模型工作在过耦合状态下,存在3个频率点能使初级回路的阻抗角为0。接着,根据这3个频率点不同的物理意义分别给出了中心谐振频率点和侧谐振频率点的定义。在此基础上对比了系统分别工作在这3个频率点上时的能量传输效率和负载吸收功率。然后,得出当系统工作在侧频率点时系统传输效率与输出功率保持稳定的结论,并依此提出将侧谐振频率点作为频率跟踪对象的频率跟踪策略。最后,通过Multisim仿真验证了上述结论。

In order to further understand the frequency-tracking magnetic coupling circuit is constructed and the relationship between the excitation source frequency and its impedance angle is studied in this paper. It is found that under certain conditions, there are three frequency points which can make the impedance angle of the original side loop zero. Then, the definitions of the center resonant frequency point and the side resonant frequency point are given according to the respective physical significance of these three frequency points. On the basis of the above studies, the energy transfer efficiencies and load absorption powers of the system working at these three frequency points are compared. It is concluded that the transmission efficiency and output power is stable when system working at the side resonant frequency point, and a new frequency tracking strategy is put forward that the side resonant frequency point could be made as the object of frequency-tracking. Finally, the above conclusions are veri- fied by Muhisim simulation.