A GaN Drive for Ultra-High-Speed Permanent Magnet Synchronous Motor

In this paper, a gallium-nitride (GaN) ultrahigh-speed permanent magnet synchronous motor (PMSM) sensorless drive is proposed. The ultra-high-speed PMSM has a maximum electrical frequency of 3 kHz. Thus the utilization of high-switching frequency devices becomes essential. The developed 3-phase GaN inverter achieves 40 kHz switching frequency, thereby increasing the control performances of the machine. Besides, due to the absence of speed sensors in ultra-high-speed applications, a secondorder sliding-mode observer (SMO) is implemented for position and speed estimation. The SMO shows a fast dynamic response and strong robustness in the results of the recent simulations. A harmonic injection modulation algorithm is implemented to reduce the computation load of the digital signal processor (DSP). Synthesized by the GaN inverter, the SMO, and the harmonic injection modulation algorithm, the ultra-high-speed PMSM drive achieves highefficiency and high-dynamic performances.