Design and analysis of concave-core stator direct-drive permanent magnet motor

To solve the problems mechanically caused by parallel direct-drive permanent magnet motors (DD-PMSM). This paper proposes a concave-core stator direct-drive permanent magnet motor (CCSDD-PMSM) structure. In this study, an auxiliary yoke structure is proposed to optimise the magnetic circuit and analyse the cogging torque to achieve the minimum detent force. Based on the unit motor and combined with the magnetomotive force to analyse the symmetry of different winding distributions, the stability characteristics of the motor are studied. The magnetic field distribution of the motor load air gap is calculated using the finite element method. The contribution of different spatial order harmonics to the motor output torque is calculated using the Maxwell tensor method. The torque calculation expression of the CCSDD-PMSM is given. Finally, an experimental prototype is made to verify the accuracy of the analysis in this paper.