Modeling and analysis of levitation force considering air-gap eccentricity in a bearingless induction motor

This paper presents modeling and analysis of levitation force considering air-gap eccentricity in a bearingless induction motor. By using nonlinear transient field analysis of finite element method (FEM), levitation force is calculated under air-gap eccentricity. An analytical analysis of interaction between harmonic field components due to air-gap eccentricity is put forward. A simplified modeling for levitation force control is developed based on the theoretical analysis and calculated results by FEM.