Impact of High-Frequency Distributed Parametric Cable Model and Motor Terminal Overvoltage in SiC-Based Drives

Silicon carbide (SiC) devices are characterized primarily by their high switching frequencies and rapid switching speeds. However, these faster switching speeds result in elevated voltage change rates (dv/dt), which in turn induce overvoltage at motor terminals. This overvoltage phenomenon places significant stress on motor winding insulation and bearings. In order to more accurately predict the overvoltage phenomenon of the inverter-cable-motor systems employing fast-switching SiC devices. This paper proposes a novel high-frequency cable modeling method for SiC drive systems, based on parameter fitting. This model is constructed using cable physical parameters obtained through impedance analyzer measurements. This approach offers advantages over existing high-frequency models, including simplified parameter extraction and accelerated computer simulation times. To validate the model's accuracy, we compare its predicted results against actual experimental measurements. The study further investigates the impact of cable length and voltage rise time on motor overvoltage (SiC system), utilizing both the proposed model and experimental verification. Experimental outcomes demonstrate that our high-frequency distributed parameter cable model accurately predicts motor overvoltage in SiC inverter systems. This research contributes to the analyzing and predicting of overvoltage issues in high-frequency switching environments, improving the reliability and performance of SiC-based motor drive systems.