Rotor Design And Research Of High-speed Permant Magnet Synchronous Motor

Because of the advantages of high power density, simple structure, reliable operation, lower losses, high efficiency and excellent control performance, permanent magnet synchronous motor(PMSM) is very suitable for high-speed application, and is the mainstream direction of high-speed motor. The high-speed permanent magnet synchronous motor(HSPMSM) is already widely used in aerospace, National Defense and other aspects of daily life. The design of HSPMSM, especially the rotor design, has some difficulty. Therefore, some key techniques of the rotor design of HSPMSM are thoroughly investigated in this thesis.The first part mainly discusses the influence of rotor electromagnetic parameters on motor performances. Firstly, the two main rotor structures of HSPMSM are analyzed and compared in high-speed application scopes. Then two key parameters, namely no-load flux leakage coefficient and no-load electromotive force(EMF), are studied. The different influence factors and regulation mechanism of the two rotor structures on the two key parameters are analyzed.The second part mainly checks the influence of the different rotor structures on mechanical properties of the rotor. At first, the two different rotor structures, surface mounted and buried magnets, are introduced and the different influences on the mechanical strength of the rotor are analyzed. Two prototypes with different rotor types are designed respectively, of which both have 630 k W and 8200r/min. Secondly, the rotor dynamics of HSPMSM are calculated with finite element method(FEM) and analytical method, and the mechanical strength of some rotor key components from the perspective of engineering application are checked in order to ensure the safety and reliability of the rotor design.The third part is emphasized on investigation of the rotor temperature field of HSPMSM, which is indispensable for the rotor design. The two main factors affecting the rotor temperature are rotor eddy current and mechanical friction losses respectively. The methods of how to calculate these losses are firstly discussed. Then the equivalent model of rotor temperature field is built according to the boundary conditions and material properties. Finally, the rotor temperature field of HSPMSM with FEM is analyzed, and the result is comparable with that of the analytical calculation.