Sensorless position control of an axial flux-switching permanent-magnet motor based on high-frequency pulsating voltage vector injection

Flux-switching permanent magnet (FSPM) machines are novel brushless machines having magnets in the stator and currently are under intensive research due to their novel features, such as simple and robust rotor, flux focusing effect, sinusoidal phase back-EMF, high torque/power density and high efficiency. In this paper, a sensorless high-frequency sinusoidal signal injection scheme for a novel yokeless and segmented armature axial flux-switching sandwiched permanent-magnet motor (YASA-AFFSSPM) is proposed. Firstly, pulsating voltage injection is investigated in detail. In addition, a simpler method (Direct signal process method) for position error signal processing is presented based on pulsating signal injection. The principle and the realization of this method are analyzed in depth. Through experiment, the traditional signal process method and direct signal process method with high-frequency pulsating sinusoidal signal injection are compared to verify the validity these methods.