Separation of each torque component on parts of electric machine using magnetic force density

For the mechanical structure design of electric machines, each force component on the parts of an electric machine need to be separated. In this paper, a separation scheme of each torque component is presented. It is based on the magnetic force density analysis of the general formulation of equivalent magnetic charge method and Lorentz force density. The force density analysis can be applied to all parts of the system region including the inside of material and the interface of different materials. An interior permanent magnet motor and a surface permanent magnet motor are adopted for numerical test in this paper. Their numerical results show validity and usefulness of the presented method.