Design Of Axial-field Permanent Magnet Motor With Amorphous Alloy Stator Core

Amorphous alloy can reduce coreloss remarkablely when applied in high-frequency motor. Effects of topological structures on motor performance are mainly studied in this paper, and so do some relevant design techniques of high-frequency permanent magnet axial-flux synchronous motor with amorphous alloy stator core(AAPMSM), considering of the special problems during motor designing.Firstly, Kaman and Torus structures of AAPMSM are studied contrastively. Effects of topology structures on manufacturability, electromagnetic performance and temperature field are analyzed. Fixing means of amorphous alloy stator and design based complexity of water-cooled cooling system are compared. Power density, leakage flux and air-gap field of each topology structure are studied furtherly, and proper ranges of flux density in amorphous alloy core and current density in winding are deduced respectively, to be a reference in AAPMSM designing.Secondly, a program for electromagnetic calculation of Torus AAPMSM is compiled in Fortran. The narrowest tooth-width is checked. Current density, thermal load, and copper loss both in series and parallel, and flux density in stator yoke both in NN and NS magnetic path are calculated, considering of the sensibility of Amorphous alloy to mechanical stress and the particularity of axial-flux structure. Then, the program is verified by prototype debug and finite element method(FEM), which could be used in AAPMSM designing.Finally, a Torus AAPMSM of 7kW and 4000r/min is designed and optimized. Several special problems during AAPMSM designing are proposed: the lower saturated value and heat conductivity of amorphous alloy core, the axial magnetic pull caused by axial-field, and the degree of symmetry results from assembling, which are weaken by optimal electromagnetic design. Pole-slot combination, main sizes, air-gap length and pole-arc coefficient are selected, and the standard 4-parts Halbach PM array format by 45° magnetizing is adopted. Last, main losses and temperature field are calculated by the FEM, to check the designing scheme.