Three-phase Asynchronous Start To Optimize The Design Of Permanent Magnet Synchronous Motor

Line-start Permanent Magnet Synchronous Motor(Line-start PMSM) is a very high efficiency synchronous motor designed to operate at fixed frequency and voltage. It is different from Variable-speed Permanent Magnet Synchronous Motor, as a squirrel cage is provided in the Line-start PMSM to accelerate the rotor from standstill when started across the line. Compared to the traditional three-phase Induction Motors, the Line-start PMSM has typical advantages such as higher efficiency and power factor within a wide load range. It accords with the national guideline of "energy-saving and environment-protecting" and has good future of industry application.The Line-start PMSM has been widely studied since it first been presented. Now, the design technology for this kind of motor is maturing via more than twenty years' development, and it has been applied on some particular industrial occasions. However, due to the complexity of the magnetic circuit in the Line-start PMSM, the optimal design methods need further improving.This thesis aims at optimal analysis and design of three-phase Line-start PMSM. Motors with simpler structure, lower cost and better performances are pursued in the process of study. FEM Simulation software such as Maxwell/2D, Magneforce and Magnet are used to analyze the influences of magnet embedding depth, number of slots in rotor and stator, saturation of magnetic circuit and so on, in Line-start interior permanent magnet synchronous motor.Finally, a prototype Line-start PMSM with 4 magnetic poles was designed and manufactured by the author. Results that measured from experiment andsimulation were approximately the same, and the prototype essentially satisfied the design request. After then, measure was taken to further optimize the design.In conclusion, the study of the Line-start PMSM has both theoretical and practical values.