基于逆变器端口模型的电磁干扰滤波器设计

逆变器的噪声源阻抗对电磁干扰（EMI）滤波器的滤波效果有较大影响，在设计滤波器时有必要对逆变器的噪声源阻抗进行提取和分析，研究基于逆变器端口模型的无源EMI滤波器设计方法. 建立逆变器的端口电磁干扰等效模型，通过测试逆变器的端口电压和端口电流，采用优化算法提取逆变器的等效噪声源和等效源阻抗. 在考虑噪声源阻抗、负载阻抗以及滤波元件高频特性的情况下，采用优化算法计算滤波元件参数，实现EMI滤波器的量化设计. 针对接入滤波器后部分频点共模干扰超标的问题，分析发生谐振的原因，提出阻尼电路的设计方法. 接入所设计的EMI滤波器进行实验，逆变器输出线的电磁干扰符合标准，验证了所提出的EMI滤波器设计方法.

Electromagnetic interference filter design based on terminal model of inverter

The noise source impedance of inverter has a great influence on the filtering effect of electromagnetic interference (EMI) filter, and it is necessary to extract and analyze the noise source impedance of inverter when designing the filter. A passive EMI filter design method based on terminal model of inverter was studied. A terminal EMI model of inverter was established. By measuring terminal voltage as well as terminal current of inverter and using optimized algorithm, the equivalent noise source and the equivalent source impedance of inverter were extracted. Considering the noise source impedance, the load impedance and the high-frequency characteristics of filter components, optimization algorithm was used to calculate the component parameters of filter, so as to realize the quantitative design of EMI filter. For the problem that common-mode EMI at some frequency points exceeded limit after connecting the filter, the cause of resonance was analyzed, and a damping circuit design method was proposed. Connecting the designed EMI filter for experiment, EMI of the inverter output lines met the standard, which validated the proposed EMI filter design method.