共振磁耦合无线电能传输系统参数与电磁分布特性仿真研究

Parameters and Electromagnetic Distribution Characteristics of Wireless Power Transmission System Based on Magnetic Resonant Coupling

为进一步改进共振磁耦合式无线充电系统的低频化问题,利用二端口网络参数理论对共振磁耦合无线电能传输系统进行建模,分析了系统传输效率与功率和S参数的关系,指出传输效率最大化的条件,提出了降低无线电能传输系统工作频率的必要性,并结合低频化设计思路,针对铜贴片改变进行HFSS本征频率仿真,得到系统共振频率和贴片厚度、距离、摆放位置等之间的关联,基于仿真结果为共振线圈选择合适的品质因数和共振频率。最后针对典型的共振磁耦合传输系统传输通道上的电磁场分布特性进行计算,得到磁场强度分布,比较了加入屏蔽体之后对传输系统的性能影响和屏蔽体效果,提高了系统传输效率。

The theory of two port network parameters was used to model and analyze the magnetic resonant coupling wireless power transmission system. The relationship between the transmission efficiency, transmission power of the sys- tem and the parameter S was analyzed. The necessity to reduce the working frequency of the wireless power transmission system was proposed. Combined with the design of the frequency reduction, the eigen frequency with changes of copper patch was simulated in HFSS. The relationship between the resonance frequency of the system and the thickness, dis tance and position of the patch was obtained. The appropriate quality factor and resonant frequency of the resonant coil were selected based on the simulation results. Finally, the distribution characteristics of electromagnetic field in the trans- mission channel of the typical magnetic resonance coupling transmission system were calculated, and the influence of the shield on the performance of the transmission system was verified, which improved the transmission efficiency of the system.