单相逆变器共模电磁干扰特性研究

Research on Characteristics of Common-mode EMI in Single Phase Inverter

在逆变器系统中,开关器件的高速开关产生了巨大的dv/dt和di/dt,形成了严重的电磁干扰(EMI)问题.介绍了逆变器在实际运行中产生的共模电磁干扰(CM-EMI)及其产生机理,得出了共模干扰源和传播路径,建立了单相逆变器共模干扰等效电路.通过分析回路参数和驱动脉冲延时不一致对共模干扰的影响,揭示出干扰抑制中前期工作的重要性,并提出了相应的解决方案,即以干扰源作为研究对象,对逆变器共模干扰进行特性分析与初步消除.仿真及实验结果表明,该方法可以有效消除逆变器产生的CM-EMI,从而保障逆变器正常工作.

In inverter system,high dv / dt and di / dt due to fast switching of power devices could bring serious electro-magnetic interference（ EMI） issues. Common-mode EMI（ CM-EMI） generated by inverter in actual movement and its generating mechanisms were introduced,the origin and propagation path of CM-EMI were highlighted,and a simple equivalent circuit was established to study the CM-EMI in single phase inverter. By analyzing the effects on CM-EMI owing to the circuit parameters and the inconsistent drive pulse delay,the significance of preliminary works in interference suppression was revealed and corresponding solutions were proposed,that was to say,analyzing and eliminating CM-EMI by interference source. Simulative and experimental results showed that the method was effective for reducing CM-EMI.So it could ensure inverter to run regularly.