感应电机传导干扰频段Π型共模等效模型

Novel π-type Conducted Common-mode EMI Model for Induction Machines

脉宽调制(pulsewidth modulation,PWM)逆变器产生的共模电压会在感应电机内部的寄生耦合回路中产生共模耦合的漏电流和轴电流,带来显著的负面效应。为研究PWM驱动系统的共模电磁干扰,在分析电机内部寄生参数的基础上,指出感应电机绕组可视为均匀传输线,且共模电流沿绕组传播时的阻抗为定值。据此提出一种构建感应电机传导干扰频段高频共模等效电路的实验方法,并建立新型π型等效电路,适用于分析和预测PWM电机驱动系统整个传导干扰频段(0.15～30MHz)的传导共模电磁干扰。仿真和实验结果验证了该模型的正确性。

Common-mode voltages generated by pulse width modulation （PWM） inverters can produce leakage and bearing currents in parasitic coupling loops inside induction machines and bring negative effects. In order to study common-mode electromagnetic interference （EMI） in PWM drive system, based on the analysis of parasitic parameters inside induction machines, indicates that the winding can be regarded as the evenly distributed transmission line, and the impedance is constant when the common-mode current passes along the winding. A novel experimental method to build high-frequency common-mode equivalent model of induction machines is proposed. The π-type equivalent circuit built based on the proposed method is available to analyse and predict common-mode EMI of PWM motor drive systems within the whole conducted EMI frequency band （0.15-30 MHz）. The proposed model is validated by simulation and experiment.