Research On The Starting Performance Of Line-start High-voltage Permanent Magnet Synchronous Motor With Different Rotor Structures

The Line-Start Permanent Magnet Synchronous Motor (LS-PMSM) has the advantages of high efficiency and high power factor. If the LS-PMSM can promote application in high energy consumption industries such as mining machinery, petroleum machinery, metallurgical machinery and electrical machinery, that is good for the implementation of the national police "energy conservation and environmental protection" and releasing the condition of energy scarcity. However, due to structural reasons, the starting ability of LS-PMSM has been seriously affected, so the starting performances of LS-PMSM with different rotor structures are very necessary to studyThe 6kV, 315kW high-voltage LS-PMSM is developed, whose structure is different from an ordinary PMSM, that it requires special insulation measures. This paper focuses on the process of starting, the process of pulling into synchronization, and the overload condition after leading into the synchronous speed. Then the starting torque, pull-in torque and pull-out torque of the LS-PMSM were calculated, and the interacting relationships among torques were compared. The starting performance, which impacted by the structures and materials of cages, and the structures of rotor core and arrangement of permanent magnet, were analyzed.Next, the cage bars of LS-PMSM were chosen to be studied, from the points of no-load air-gap magnetic field and harmonic to explain the cage bar affecting the starting performance, and the correlation analysis among structures, materials and the starting performance were done in detail. All the works can provide reference to establish the optimal combination scheme cage for the LS-PMSM.The features of rotor structure were taken into account, and a method to improving starting ability of a laminated rotor of high-voltage LS-PMSM was researched. Considering the starting performance to be further improved, a new rotor model which used of Halbach array was brought forward. The feasibility and the advantage on starting of this new structure were confirmed by calculating the magnetic field in air-gap and simulating the starting process.A series of useful conclusions were obtained, which could supply a helpful reference to the further study on high-voltage LS-PMSM.