Development of High-Frequency WBG Power Modules with Reverse-Voltage-Blocking Capability for an Integrated Motor Drive using a Current-Source Inverter

Integrated motor drives (IMDs) can provide high power density, simplified installation, and easier retrofits for fixed-speed motors with adjustable speed drives (ASDs) in pump/fan applications. This paper proposes a new IMD based on a current-source inverter (CSI) topology that offers several performance improvements over existing IMD configurations. Attention is focused on development of suitable power electronics modules that have reverse-voltage-blocking (RB) and high switching frequency capabilities. Several candidate hybrid switch configurations using MOSFETs, IGBTs and HMI's for RB switches are examined. Test results for three prototype hybrid RB switch power modules using discrete GaN-HEMTs and SiC-MOSFETs are presented that exhibit promising performance characteristics including low conduction loss and fast switching capabilities in a high-temperature (T-j = 125 degrees C) environment. Mechanical and thermal design issues are also addressed that are keys to achieving reliable operation of the power modules. Simulation and experimental results are used to estimate the CSI efficiency in an IMD configuration, yielding rated efficiency values as high as 97.7% using the hybrid WBG-based RB switches.