Abstract
Recently, finite element method (FEM) that is one of the calculation method of non-linear electromagnetic equation used for analysis of a motor characteristic. It is important to analyze the motor by using FEM as well as the equivalent circuit analysis for its design and applications. We have proposed a new-type induction motor that has free-rotating magnets inside the rotor (IMFM). IMFM has a squirrel-cage type rotor and a magnet rotor inside the rotor. The rotor and the inner magnet rotor are driven at different rotational speed. Therefore, it is difficult to analyze IMFM by using FEM. In this paper, we propose a new FEM application technique for analyzing IMFM. In this method, we gave different speeds to the inner magnet rotor and the rotor respectively, and adjusted the phase of the applied voltage so that the magnet rotor does not generate the output torque. The characteristic between the torque and the rotational speed obtained by the magnetic field analysis of IMFM was matched well with that of the experimental results in the practical slip range.
