Integrated Motor Drive using Soft-Switching Current-Source Inverters with SiC- and GaN-based Bidirectional Switches

The combination of wide-bandgap (WBG)-enabled current-source inverter (CSI) and integrated motor drive (IMD) has been shown to provide several advantages compared to voltage-source inverter (VSI)-based motor drives either with long output cables or in IMD configurations. However, the higher conduction loss associated with using conventional switches with series diodes in the CSI makes thermal cooling of the CSI-IMD more challenging. To relieve this cooling challenge, new soft-switching CSI topologies using bidirectional (BD) switches have been designed, built, and tested for IMD applications. The operating characteristics of alternative CSI topologies using multiple SiC and GaN candidate devices are analyzed for varying junction temperatures. Hybrid BD switches consisting of two discrete switches connected in anti-series are used for this investigation. It has been experimentally demonstrated that the new CSI topologies achieve higher efficiency compared to conventional hard-switching CSIs using reverse-blocking (RB) switches, making them appealing for IMD applications.