Impact of High Switching Speed and High Switching Frequency of Wide-Bandgap Motor Drives on Electric Machines

The emergence of fast-switching wide-bandgap (GaN, SiC) power electronics devices has enabled motor drive systems to achieve high efficiency, density, control bandwidth and high-level integration. However, the speed switching frequency result in an increased level overvoltage at both terminals stator neutral. This increases stress across winding insulation bearings. paper investigates three types overvoltages, i.e., differential mode (DM) (phase-to-phase) terminal overvoltage, common (CM) (phase-to-ground) CM neutral (motor ground). Both (high dv/dt) effect on are investigated this paper, where not been fully addressed existing literature. Significant is observed when or its multiples coincide with cable anti-resonant frequency. behavior impedance used identify oscillation explain observations for overvoltages. analysis tested using a 7.5kW setup without four-core cable, driven by SiC GaN three-phase inverter up 250kHz 40kV/ μs. In addition, bearing current, which main cause degradation, also increase current due effect.