三相逆变器共模传导电磁干扰的建模与分析

摘要

It is necessary to research the modeling and analysis method of the conducted electromagnetic interfer ence (EMI) in a three-phase inverter for the purpose of predicting and suppressing its common mode (CM) con ducted EMI. In this paper, based on an analysis of the switching sequence and conducting states of the switching devices of the inverter, a simple and convenient equivalent circuit model of the inverter is proposed consisting of the models of its CM conducted EMI noise sources and their propagation path. The high frequency parameters of the model are obtained by measurement and electromagnetic field numerical calculation. Simulations using the proposed model and an experiment have been conducted on a three-phase inverter system. The experimental and simulation results of the EMI spectrum match with each other over the frequency range from 150 kHz to 30MHz, which demon strates that the proposed model is valid and effective. This analysis method can be used to evaluate the CM conduc ted EMI in three-phase inverter systems.%为了预测进而抑制三相逆变器的共模传导电磁干扰( EMI),需要研究其建模和分析方法.本文首先通过对三相逆变器各个开关管的开关状态的分析,得到了三相逆变器共模传导EMI干扰源的简便表示方法,进而提出一种由共模传导EMI干扰源和传播通道模型构成的等效电路模型.通过实验测量和电磁场数值计算,获得等效电路中的各个高频参数.对其共模传导EMI进行仿真和实测,150kHz～30MHz频段的仿真与实测频谱基本吻合,说明采用本文方法建立的共模等效电路模型是可行的.该方法可作为计算评估三相逆变器共模传导EMI的一种可行方案.