The series structure dual-rotor PMSM design based on phase-shifting winding

For satisfying the requirement of high performance motor used in modern precise direct drive numerical control (NC) rotary table, a dual-rotor permanent magnetic synchronous motor (PMSM) with series structure and phase-shifting winding is designed in this paper. The series structure induces the magnetic fields of the inner unit motor and the outer unit motor to rotate synchronously, so the synchronous control problem of the two unit motors is resolved essentially. The inner space of the rotary table is occupied by the dual-rotor PMSM vastly in order to obtain higher torque. The phase-shifting winding structure makes the inner unit motor and outer unit motor generate the converse cogging torque ripple. As a result, the compositive cogging torque ripple of dual-rotor PMSM is decreased effectively. By the finite element method (FEM) analysis and calculations, it can be obtained that the average torque of the dual-rotor PMSM is increased by 24.6% compared with the traditional PMSM and the cogging torque ripple of dual-rotor PMSM with phase-shifting winding is decreased by 55.9% compared with the one without phase-shifting winding.