Integrated Modular Motor Drive Design With GaN Power FETs

This paper explores the use of GaN power FETs to realize an integrated modular motor drive (IMMD) with an induction motor. A structure in which inverter modules are connected in series is proposed to reduce the module maximum voltages and to offer an opportunity to utilize low-voltage wide-band-gap GaN devices. With the superb switching performance of GaN power FETs, a reduction in IMMD size is achieved by eliminating inverter heat sink and optimizing dc-link capacitors. Gate signals of the IMMD modules are interleaved to suppress the total voltage ripple of dc-link capacitors and to further reduce the capacitor size. Motor winding configurations and their coupling effect are also investigated as a part of the IMMD design. The proposed structure and design methods are verified by experimental results.