Dual-Pole Line Start Synchronous Machine With Consequent-Magnetic Poles

This paper presents a new design of dual-pole (4-pole and 8-pole) Line Start Synchronous Motor (LSSM) with consequent magnetic pole structure. The proposed structure reduces the Permanent Magnet (PM) volume in the rotor core by 67 percent with respect to the reference dual-pole machine. Given the direct impact of the PM magnetic field on producing negative torque components such as braking torque and pulsating torque, lower PM volume can potentially limit the production of such negative torques. Therefore, in addition to cost saving benefits, the proposed structure contributes to a smooth start-up process. Meanwhile, different geometrical structures of PMs and flux barriers are discussed, their impacts on the overall motor performance are highlighted, and general design guidelines are provided. In particular, six different rotor structures with different PM arrangement and/or flux barrier arc angle are analyzed in Finite Element (FE) and their steady-state and transient performance metrics are compared. Finally, the best motor candidate is selected for further analyses, and prototyping.