变频调速系统共模电流耦合干扰研究

现代变频调速系统多为电压源逆变器驱动感应电机的拓扑形式。逆变器由快速开通和关断的IGBT产生高频和快速上升和下降的脉宽调制电压，在系统中产生严重的共模电流干扰。长的电机驱动电缆中的干扰电流会通过感性或容性耦合的形式将干扰引入到周围的其它电路中去。本文主要研究了典型交流电机驱动系统与敏感电子设备共用接地平面时的感性耦合干扰，给出了分析耦合干扰的模型和实验结果。

Common-mode Current Coupled EMI in AC PWM Systems

The most common solution for modern adjustable speed drives is the use of induction motors fed by voltage-source inverters. The inverters using fast switching insulated gate bipolar transistors （IGBTs） generate pulse-width modulated （PWM） voltage pulses. The high carrier frequency along with fast rise and fall time of the PWM switching results in nontrivial common-mode or ground currents noise. The current component can cause electromagnetic interference （EMI） noise to neighbour equipments and installations by either radiation from the motor cable or by cross-talk （inductive and capacitive coupling） with other conductors. In this paper, it is discussed the inductively coupled EMI noise from an ac drive system, where there susceptible devices and a common ground plant are presented. The model describing the sophisticated EMI phenomenon is proposed and measurement results are presented.