EMI EVALUATION OF POWER CONVERTERS CONSIDERING IGBT SWITCHING TRANSIENT MODELING

The major high frequency EMI source of the power converter is the changes of high voltage and current (dv/dt and di/dt) during the switching instant associated with the devices.An improved and simplified EMI modeling method is proposed considering the IGBT switching behavior model,then the device turn-on and turn-off dynamics are investigated by dividing the nonlinear transition in several stages.The real device switching voltage and current are approximated by piece-wise linear lines and expressed using multiple dv/dt and di/dt superposition.The derived EMI spectra suggest that the high frequency noise is modeled with an acceptable accuracy.The proposed method is verified by experimental results.