大功率三相两级π型共模EMI滤波器的近场耦合分析

Analysis on near-field coupling of high-power three-phase two-stage π-type common-mode EMI filters

EMI滤波器是抑制电力电子设备传导干扰的重要手段,其高频性能受内部近场耦合的影响显著,因此对EMI滤波器内部近场耦合进行准确分析是预测滤波器实际性能的关键。对大功率三相两级π型共模EMI滤波器的近场耦合开展研究,理论分析了影响其滤波性能的关键近场耦合参数,仿真计算了耦合参数和建立了高频等效电路。仿真与测试结果表明:输入环路与输出环路之间的磁场耦合以及输入走线与输出走线之间的电场耦合是影响大功率三相两级π型共模EMI滤波器性能的关键。

EMI filter plays a key role to suppress conducted interferencein power electronic equipment,and the performance is significantly affected by the internal near-field couplings,therefore,the accurate analysis of the internal near-field couplings in EMI filter is the key to predict the actual performance of the filter.In this paper,the near-field couplings of high-power three-phase two-stageπ-type common-mode EMI filter is studied,the key near-field coupling parameters affecting the filter performance are analyzed theoretically,and the coupling parameters are calculated and the high-frequency equivalent circuit are established.The simulation and test results show that the magnetic field coupling between input loop and output loop,the electric field coupling between input and output trace are the key factors affecting the performance of the high-power three-phase two-stageπ-type common-mode EMI filter.