High-Frequency Modeling of the High-Voltage Electric Drive System for Conducted EMI Simulation in Electric Vehicles
Kunbo Wang, Hongmin Lu, Xiaojian Li
Abstract
To address the problems of the existing motor behavioral models, which are not suitable for time-domain simulation, difficult to parameterize, cannot capture multiple resonances, and neglect the low-impedance antiresonance phenomenon, a motor behavioral modeling approach based on series and parallel resonances in common-mode (CM) and differential-mode (DM) impedance is first proposed. Compared with the measured results and existing models, the presented motor model indicates significant improvements in terms of accuracy, universality, and convenience. Second, a high-frequency model of the high-voltage electric drive system (EDS) is developed based on the cable model, the inverter model, and the novel motor behavioral model, which considers various parasitics at high frequencies. Comparison with experimental results depicts that the novel EDS model can effectively predict system-level conducted electromagnetic interference (EMI) up to 100 MHz with an error of 5 dB or less at most frequencies. Finally, compared with the existing frequency modeling technique, it further demonstrates that the proposed EDS modeling method displays significant superiority in respect of improving prediction precision and applicable frequency range.