Magnetoelastic coupling in rotating electrical machines

This paper presents a method for the calculation of vibrations in rotating electrical machines when the magnetoelastic coupling is to be taken into account. A dynamic model for the magnetoelastic coupling is presented, where the circuit equations for windings of the machine are also coupled with the magnetic field. Calculation results for coupled and uncoupled cases are compared. It is shown that the calculated vibrations of the stator of a synchronous generator are different when the coupling is taken into account. Depending on the considered vibration frequency, an increase or decrease of the amplitudes of vibrations of about 20% is noticed due to the magnetoelastic coupling. This phenomenon has to be accounted for when modeling the vibrations of large stator cores, which are not very stiff mechanically.