Numerical analysis of the contribution of magnetic forces and magnetostriction to the vibrations in induction machines

A method is proposed to calculate the vibrations of magnetised electrical steel due to magnetic forces and magnetostriction. As an example, calculations have been carried out on two-pole and four-pole induction machines (IMs) with no load. If only the main components of the vibrations are considered, analysis of the results reveals that, in the case of the two-pole IM, the contributions of the magnetic forces and the magnetostriction add up, whereas, in the case of the four-pole IM, the respective contributions are subtracted. It is concluded that it is not justified to assume that magnetostriction in all cases will increase the vibrations of electromechanical devices