Modeling of High Voltage to Low Voltage Crosstalk Coupling Paths in Electric Vehicle Motor Drive Systems

A method for modelling the equivalent circuit of the LV and HV coupling path of a motor drive system based on port impedance measurement is proposed. First, the crosstalk coupling mechanism of the HV system to the LV system is analysed. Then, the crosstalk coupling path model is established by measuring the S21 parameters of the HV and LV coupling paths of the cable, the controller, and the motor drive system respectively. The deviation between simulations and experimental measurements is less than 8 dB, which indicates that the established crosstalk path model has a good accuracy. By using the coupling path model to conduct HV and LV crosstalk coupling analysis, it can be seen that reducing the length, spacing, ground clearance, and load impedance of HV and LV cables can effectively reduce HV and LV coupling. Reducing the parasitic capacitance of the HV power circuit of the motor controller to the ground and the inductance of the HV and LV circuits can effectively reduce the internal crosstalk coupling of the controller.