Application of a computationally efficient air-gap element within the finite element analysis of magnetic bearings

This paper presents finite-element analyses of radial magnetic bearings where noncentered rotor positions are considered very efficiently. With an introduction of a reformulated air-gap macro element, distinct stator and rotor models can be used, and remeshing of the air gap is avoided. Therefore, static and dynamic rotor eccentricities can be considered very easily. The force-current relations for a typical design of a radial magnetic bearing with four pole pairs in two orthogonal directions are evaluated with both conventional finite-element models and models based on the eccentric air-gap element