Rotor dynamics and stator vibrations of a novel IPM synchronous motor

Abstract

The paper presents rotor-dynamical computations of a technology demonstrator of an interior permanent magnet (IPM) synchronous motor that was designed at the Research and Technology Centre of Siemens AG in the framework of the European funded project named MotorBrain. The computations were split into parts consisting modal and harmonic analysis performed numerically using FEM algorithms and the post-processing estimation of the amplitudes of rotor displacement and velocity in the whole range of motor rotation speed. Authors determined modal damping ratios of different oscillation modes and found values of resonance frequencies. In a further step forces were applied to the rotor in order to determine oscillation amplitudes of points placed along the rotor geometrical axis in the case of both mechanically and electromagnetically excited rotor. The computations were performed for the excitation of the first and the second flexural vibration. Except of rotor-dynamical computations authors performed vibration analyses of the stator together with the motor housing. The stator resonance frequencies and its modal deformation shapes were determined. In a further step electromagnetic forces acting on stator teeth were numerically found. These forces were then applied on each stator tooth in order to perform harmonic vibration analyses and determined the spatial average velocity of motor housing circumference area .