Vibration Analysis of an Electric Motor with Mechanical and Electromagnetic Interaction

Abstract

In this study, the vibration of an electric motor is analyzed when mechanical and electromagnetic interaction is considered. After obtaining the kinetic, potential and magnetic energies for the motor, the equations of motion are derived by using Lagrange's equation. These equations are nonlinear equations in which the displacement of motor center and the current of coil are coupled to each other. By applying the Newmark time integration method to the equations, the dynamic responses for the displacement and current are computed. It is found that the mechanical responses are influenced by the electromagnetic properties. In particular, it is shown that the variation of air-gap due to vibration induces the inductance of the motor coil.