Investigation of the causes behind the vibrations of a high-speed solid-rotor induction motor

This paper analyzes the causes of vibrations in a solid-rotor induction motor (SRIM) through electromagnetic Finite Element (FE) simulations and laboratory measurements. The computed results are compared with vibration measurements, and the electromagnetic causes of vibrations were discovered, including the fault related reasons. The machine under investigation is a 300 kW, 60 000 rpm, three-phase SRIM. The FE simulations are carried out in an open source FE library implemented in Matlab. Both magnetic forces and magnetostriction deformations are accounted for in the simulations. This magneto-mechanical coupling is implemented using a free-energy-based model. The harmonic analysis of the vibrations revealed that, the supply frequency components, the magnetic forces and the magnetostriction contribute to the electromagnetic causes of vibration, while there is a significant amount of vibration produced due to the rotor eccentricity in the motor.