Expert System-Based EMI Modeling Method for IGBT in Electric Drive System of EV

In the working process of the electric drive system, the transient, high-amplitude, high-frequency voltage and current generated by the turn-on and turn-off of the IGBT (Insulated Gate Bipolar Transistor) are the most important sources of electromagnetic interference in EVs (electric vehicles). To this end, this paper proposes an EMI (Electromagnetic interference) modeling method for IGBT power modules of electric drive systems, which can realize accurate simulation of EMI source characteristics. First, an expert system based on IGBT model library is proposed. Then the expert system is used to simulate the characteristic curves provided in the IGBT module datasheet and extract the key parameters. Based on the expert system, an IGBT behavioral model is established, and a double-pulse simulation circuit is built to evaluate the simulation waveforms of the collector-emitter voltage, gate-emitter voltage and collector current during the two pulse switching periods. At the same time, measure the collector-emitter voltage, gate-emitter voltage and collector current test waveforms collected in the above simulation test on the built double-pulse test circuit, and compare the turn-on and turn-off processes of the simulation and test respectively to evaluate the accuracy of the EMI source model. Finally, to further test the universality of the model, the IGBT behavior model and the double pulse simulation circuit are established on the Simulink platform, and the accuracy of the model is evaluated by comparing with the test waveform. The comparative analysis results show that the proposed EMI source modeling method for IGBT power module has good versatility and accuracy.