Rotor optimization of interior permanent magnet synchronous motor considering mechanical stress

This paper presents the design method of rotor bridge of interior permanent magnet (IPM) motor. Among design parameters, the bridge is an important factor because it affects a mechanical cracking and electrical performances. When we design the bridge of IPM motor, a mechanical stress analysis should consider a centrifugal force and electromagnetic forces. A total force of above forces is a stress source of the bridge. Electromotive force (EMF), cogging torque, and torque are calculated by finite element method with Maxwell stress tensor method. The Von Mises criterion is applied to the mechanical stress. As the electromotive forces are considered, the bridge width can be reduced 43% compared with the bridge width considering only the centrifugal force.