Modeling of Eccentricity-Induced Radial Forces in a Permanent-Magnet Synchronous Motor

When the rotor of a permanent-magnet (PM) synchronous motor has some eccentricity, the magnetic field distribution in the air gap between the rotor and stator changes. As a result, the radial forces are occurred in a PM synchronous motor and is a common source of noise and vibration. In this paper, we describe a model that predicts the radial forces due to eccentricity in a PM synchronous motor.