Modeling Rotation in Electrical Machines

This paper is about finite element kind of modeling of movement in electromechanical devices, especially in rotating electrical machines. The presented approach relies on geometry and manifolds. With an appropriate choice of charts, the spatial and temporal discretizations become decoupled, which implies that the spatial finite element mesh no longer restricts the allowed time steps. However, the standard basis functions of finite elements are not always powerful enough to support large changes in the rotation angle, and therefore in case of thin air gaps, an intermediate approach between the lock-step method and the choice of charts is preferable. This is also demonstrated in the latter part of this paper by an induction machine test example.