Modeling magnetic saturation for the design of exterior rotor permanent magnet machines

This paper presents a concept in the form of a flow chart for analyzing and designing permanent magnet machine by finite element method (FEM) including rotor motion. According to our flow chart, geometry modeling will automatically be made by script. Therefore, it is easy in changing design parameters. Two programs have been developed based on the proposed flow chart, one for static solution and the other for nonlinear transient solution. The magnetic saturation model and solvers have been discussed. These ensure that the FEM program is convergent and runs faster during high saturation. The influence of slot opening on the magnetic field and internal voltage is investigated. Results are used to select slot opening for maximizing internal voltage.