Analysis And Optimization Of Linear Switched-Flux PM Machines With Odd Primary Poles And Less Permanent Magnet

In recent years, switched-flux PM machines (SFPMM) become research hotpots, due to the advantages of high efficiency, high thrust force density, high reliability, and other characteristics. With the rising cost of the permanent magnet, less permanent magnet structures have been gradually concerned by researchers. Linear switched-flux PM machines (LSFPMM) can be obtained from the rotary SFPMM, but the linear formats do not exist the eccentric force problem, so the primary pole number can be odd. Therefore, the linear machines have more configurations. Based on this point, the LSFPMMs with odd primary poles and less permanent magnet volumes are put forward, and then, analyzed and optimized based on finite element analysis (FEA) in this thesis.Firstly, the operation principle of LSFPMMs is introduced. Based on convention U-core 18 primary poles LSFPMMs, the C-core and E-core 9 primary poles LSFPMMs with less permanent magnet are put forward, and then the mathematical models are introduced; Based on the these models, the selection principle of the secondary poles number are concluded. Four suitable primary pole/secondary pole combinations of C-core and E-core LSFPMMs are given. By optimizing the end assistant teeth and secondary pole teeth, the optimal C-core and E-core 9/17 primary/secondary LSFPMM were obtained. Furthermore, the influence of the longitudinal end effect is investigated by comparison the periodic model with the actual model. Finally, the performance of LSFPMM with the mechanical flux adjuster is analyzed, and then the structure parameters of mechanical flux adjusters are optimized. The results show the flux density of air gap and the normal force are decreased much, which is benefit not only to assemble, but also flux-weakening operation.