Overview of Various Aspects of Magnetization in Permanent Magnet Motors

This article illustrates various methods to ascertain magnetization, calculation of inductance, magnetic force determination. Because of instability in the price of rare earth magnets, the rare earth free PM like ferrite magnet is used. The ferrite magnets are having the advantages of getting good torque densities, not having eddy current loss due to the absence of conductivity. Magnetizer requiring a minimum number of magnetization has been discussed to minimize the magnetization and demagnetization problems. The PM motors need two-axis models for control design. But the non-linear variation of two-axis parameters changes the magnetic field distribution and saturation level in magnetization. The effect of cross magnetization and saturation are revealed in field weakening regions by performing the estimation of two-axis model parameters. The various CAD methodologies, operation of isotropic magnets, and magnetization types are discussed and reported.