Analytical estimation and reduction of conducted EMI emissions in high power PWM inverter drives

Analytical estimation of conducted electromagnetic interference (EMI) from a PWM drive system is presented. Analysis of transient behavior based on a simplified circuit model of components in a drive system is performed in both the time domain and the frequency domain. The basic models of the main circuit components responding to the switching action by power devices are described. A set of EMI suppression techniques for high power drives are proposed which have been confirmed by experiment to meet the CISPR standard limits at low cost.