Interior permanent magnet motor drive system modeling for electromagnetic interference analysis

There are serious electromagnetic compatibility (EMC) problems in electric vehicles. Among all the devices and systems, the interior permanent magnet (IPM) motor drive system arouses most serious electromagnetic interference (EMI) problem. In order to analyze and predict the interference, a systematic modeling method is presented in this paper. Insulated gate bipolar transistor (IGBT) as the interference source is modeled first to simulate the turn-on and turn-off transient waveform. The model is established following some simple steps, which means it´s easy to parameterize. Then, the model of IPM motor and its establishment approach are discussed in detail, since its the most important device in the disturbance flowing path. Finally, the system model is obtained by merging models of all the equipment consisted in it. The proposed modeling approach is verified by comparing the predicted EMI level with the measuring results of an IPM motor drive system.