Study And Design Of High Efficiency Permanent Magnet Motor Starting Performance Of The Lower-Mounted Squirrel Cage Structure

Asynchronous starting permanent magnet synchronous motor(PMSM)has both asynchronous starting capacity and advantages in power factor and efficiency compared with the same power induction motor.The application of the PMSM in industrial field has gradually aroused the attention of experts and scholars.Although asynchronous starting permanent magnet synchronous motor has many difficulties in its own design,it still has advantages over asynchronous motors.The difficulty of asynchronous starting permanent magnet synchronous motor(PMSM)is to keep the asynchronous starting ability and maintain the synchronous running ability simultaneously,so that the permanent magnet and rotor slot have to be placed in the rotor space at the same time.This structure makes the rotor space very tense.The smaller the power is,the more difficult the rotor design is.In order to solve the problem of space tension in rotor design,this paper presents a structure of the starting squirrel cage and permanent magnet in the traditional rotor structure-a high efficiency permanent magnet motor with the structure of the squirrel cage structure.In the first step,starting from the theory of asynchronous starting permanent magnet synchronous motor,two kinds of main torque in the process of motor starting are studied,and the influence of different stator and rotor parameters on the starting process is summarized.The second step,the effect of the rotor slot parameters(groove number,slot width and groove height)on the motor starting,is concluded.Then the skin effect in the starting process of the rotor convex groove is analyzed,and the specific size of the rotor convex groove is further determined.Finally,based on the rotor convex groove,taking into account the starting performance and the traction performance,a 4 pole,a power of 4kW and a lower starting squirrel cage with relatively high starting quality factor are designed to start the permanent magnet synchronous electric synchronism asynchronously.The Ansoft software is used to carry out the simulation calculation to meet the performance requirements.By comparing the asynchronous starting PMSM with the traditional rotor asynchronous starting permanent magnet synchronous motor(PMSM),the advantages and disadvantages of the permanent magnet synchronous motor(PMSM)for asynchronous starting of the squirrel cage structure are summarized.This paper has a certain theoretical and practical value for the asynchronous start of the permanent magnet synchronous motor,which can be used as a reference for the future research of the motor.