Modeling of High-Voltage to Low-Voltage Crosstalk Coupling for Electric Vehicle Motor Drive Systems

High power density and miniaturization are the core development trends for future electric vehicle (EV) motor drive systems. As the spatial layout of motor control systems grows increasingly compact with reduced inter-component distances, electromagnetic interference (EMI) noise generated by the fast switching of power electronic devices (e.g., SiC) can induce parasitic and proximity effects via the controller's inherent parasitic and coupling parameters. This noise couples into the controller's low-voltage (LV) circuits, disrupting their normal operation and even compromising vehicle safety and reliability. To address the high-voltage (HV)-to-LV EMI coupling challenge in automotive motor drive systems, this paper proposes a coupling path modeling method based on port impedance measurements. Through analyzing the HV-toLV crosstalk coupling mechanism, coupling path models are established for three scenarios: cables, the internal controller, and the overall motor drive system. Key factors affecting HVLV crosstalk coupling and its impact on the LV system are investigated. Comparisons between crosstalk coupling simulation results and experimental measurements reveal a deviation of less than 8 dB, validating the accuracy of the proposed coupling path model.