Simulation of an Integrated Driving System for Electric Vehicles Based on High-Frequency Modeling

Abstract

In this thesis a method to estimate the noise characteristics of an integrated driver system is developed through the construction of an equivalent circuit model including high-frequency parameters. Firstly, a high-frequency equivalent model of an AC motor has been made by using three-phase motor measurement data. Secondly, the parasitic elements of an inverter, which consists of a gate driver circuit and an IGBT module, is extracted from the EM simulation of printed circuit boards, packages, and chassis. Then, the parasitic elements of the motor and the inverter are included in the entire circuit model of the driver system. Several SPICE simulations using the constructed circuit model enable the identification of possible origins of conducted emission. One factor is the size of the AC motor load that is connected the inverter. Another is the parasitic capacitance of IGBTs, which conducts common-mode noise currents to ground. The other contributor is the high frequency parasitic of the motor, which may provide other common-mode noise paths. Through the simulations, we can find that the effect of the high frequency parameters is significant in the noise characteristics of driving systems, and the proposed modeling method can be effectively used in designing EV system.