Magnetization analysis of the brushless DC motor used for hybrid electric vehicle

Component magnetization and post-assembly magnetization are compared for the brushless DC motors used for hybrid electric vehicles through theoretical analysis, FEM calculation and experiment. Provided with enough magnetizing MMF, the permanent magnets can be fully magnetized both by component magnetization and post-assembly magnetization. The tested rotor surface flux densities of the component magnetization and post-assembly magnetization are consistent, and they are in good agreement with the FEM calculated values. By contrast, we prefer the post-assembly magnetization in order to overcome the problem of magnetic forces and ferrous debris during the assembly process.