Current-Source Inverters for Integrated Motor Drives using Wide-Bandgap Power Switches

TLDR

Integrated motor drives combine power electronics and motor into a single structure, offering economic benefits over fixed‑speed motors, but are traditionally implemented with voltage‑source inverters using silicon devices; recent wide‑bandgap switches (SiC, GaN) that operate efficiently above 100 kHz and 200 °C enable reverse‑voltage‑blocking current‑source inverters, prompting a reevaluation of inverter topology selection. This study examines the use of wide‑bandgap power devices in current‑source inverters for integrated motor drives, highlighting several promising features that warrant further investigation. The authors find that combining WBG devices with CSIs yields several promising features for integrated motor drives, which are currently being explored further.

Abstract

Integrated motor drives (IMDs) can deliver substantial economic benefits by replacing low-efficiency fixed-speed motors with compact adjustable-speed drives that combine the power electronics and motor into the same physical structure. IMDs are currently implemented using voltage-source inverters since this topology is naturally compatible with conventional silicon-based power devices. However, major advances in the development of new types of power semiconductor switches made from wide-bandgap (WBG) semiconductor materials such as silicon carbide and gallium nitride open intriguing opportunities for the development of reverse-voltage-blocking switches that are well-suited for use in current-source inverters (CSIs). These WBG power switches are capable of operating efficiently at high switching frequencies (>100 kHz) and high junction temperatures (>200□C). Since the selection of the inverter topology is highly dependent on the power device characteristics, the emergence of power devices with new semiconductor properties demands a reevaluation of the system configuration. This paper investigates the combination of new WBG power devices and CSIs for use in integrated motor drive applications, identifying several promising features that are now undergoing further investigation.