TITLE:
High Efficiency LSM with High Flux Density for Transportation
AUTHORS:
Nobuo Fujii, Mitsunobu Terata, Takeshi Mizuma
KEYWORDS:
Permanent Magnet, Synchronous Motor, Linear Synchronous Motor, LSM, High flux Density, High Efficiency, Linear Motor, Transportation
JOURNAL NAME:
Journal of Transportation Technologies,
Vol.1 No.4,
October
24,
2011
ABSTRACT: A new linear synchronous motor (LSM) with permanent magnet (PM) is proposed to develop a linear motor for transportation with high efficiency. The LSM has very high air-gap flux density beyond the remanent magnetization of rare earth PM, which is generated by a special field structure with rare earth PM. Two PMs are arranged to form a triangle over each pole to concentrate the flux of PMs. The maximum value of air-gap flux density is limited to the magnetic saturated value in the core of field and armature, respectively, which is about 2T. The configuration is insusceptible to armature reaction because of large equivalent magnetic resistance in the flux path. The characteristics are analyzed using a two-dimensional finite element method (FEM) considering the core material. For high air-gap flux density and small armature reaction, the very high thrust density beyond the conventional maximum value of 100kN/m2 can be obtained. Using normal thrust density with small magneto-motive force (mmf) of armature, this LSM has efficiency and power factor that are as high as or higher than a rotational motor.