Nonsingular Fast Terminal Sliding Mode Observer and Fractional-Order Software Phase-Locked Loop for Speed-Sensorless Control of Interior Permanent Magnet Synchronous Motor. - Kai-Hui Zhao; Ruirui Zhou; Jinhua She; Aojie Leng; Wangke Dai; Gang Huang (J. Adv. Comput. Intell. Intell. Informatics, 2021)