For power electronic systems, adding filters to eliminate harmonic interference is a general and effective method, but the position and parameters of filters in wireless power transmission (WPT) system will greatly affect the system characteristics of WPT. The main reason for the harmonic interference in WPT is that the harmonics in the output square wave are loaded on the resonant coil of the transmitter, so in this study, a method of harmonic elimination by adding a second-order LCR filter to the resonant part (LCR-WPT) is studied. However, the WPT resonant part is precisely matched and designed; if a filter is added at the resonant part, it inevitably affects the resonance state, system output power and efficiency of the WPT. To ensure that the LCR-WPT has good system characteristics, this study analyses the mathematical model of the LCR-WPT and deduces a design method for the filter and an efficiency optimisation formula. This study also introduces LCR-WPT applications in two different control schemes. The experimental results show that the harmonic interference of the system is significantly attenuated after the filter is added; additionally, the efficiency of the system decreases by <10%, and the system still maintains sufficient output power.

中文翻译：

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具有输入滤波器的无线电力传输系统的设计

对于电力电子系统，添加滤波器以消除谐波干扰是一种通用且有效的方法，但是无线电力传输（WPT）系统中滤波器的位置和参数将极大地影响WPT的系统特性。WPT中谐波干扰的主要原因是输出方波中的谐波负载在发射器的谐振线圈上，因此在本研究中，通过在谐振部分增加一个二阶LCR滤波器来消除谐波的方法（LCR-WPT）被研究。但是，WPT谐振部分是精确匹配和设计的。如果在谐振部分添加滤波器，则不可避免地会影响谐振状态，系统输出功率和WPT的效率。为了确保LCR-WPT具有良好的系统特性，本研究分析了LCR-WPT的数学模型，推导了滤波器的设计方法和效率优化公式。本研究还介绍了两种不同控制方案中的LCR-WPT应用。实验结果表明，增加滤波器后，系统的谐波干扰得到了明显的衰减。此外，系统效率降低了<10％，并且系统仍保持足够的输出功率。