Sensorless SVPWM-FADTC of a New Flux-Modulated Permanent-Magnet Wheel Motor Based on a Wide-Speed Sliding Mode Observer

Abstract

This paper presents a sensorless flux adaption-direct torque control (FADTC) for a new flux-modulated permanent-magnet (FMPM) wheel motor, in which space-vector pulsewidth modulation (SVPWM) and a wide-speed sliding mode observer (SMO) are adopted. SVPWM-FADTC has several advantages over conventional hysteresis direct torque control, such as low torque/flux ripples in motor drive and reduced direct axis current when the motor is operated at a light or a sudden increased load. To achieve the sensorless control of SVPWM-FADTC system, a wide-speed SMO is proposed. Compared with conventional SMO, system chattering is improved, the low-pass filter and the phase compensation are eliminated, and the estimation accuracy of the rotor position at low speed is enhanced. Numerical simulations and experiments with a 2-kW FMPM wheel motor are carried out. The results verify the feasibility and effectiveness of the proposed sensorless SVPWM-FADTC method adopted by the FMPM wheel motor.