A Post-Assembly Magnetization Method of Direct-Start Interior Permanent Magnet Synchronous Motors and Its Finite-Element Analysis of Transient Magnetic Field

A novel post-assembly magnetization method of direct-start interior permanent magnet synchronous motor is presented. The squirrel cages in the rotor are ingeniously used as exciting coils for the realization of magnetization. The advantage is that no special magnetizing fixtures are required. A finite-element method, which addresses dynamic material properties of the magnets and yet can be implemented readily in the software, is presented for finding the parameters of the magnetization circuit. A numerical computation is reported to validate the proposed method.