A Magnetic Suspension Control Strategy of Bearingless Motors with 2-phase Brushless DC Structure

This paper presents a new structure of bearingless motor whose function is applied in a 2-phase brushless DC motor. The proposed structure is illustrated and the principle of suspension force generation and magnetic suspension control strategy are found to suspend the rotor stably without mechanical contact. The rotational torque and suspension force are computed by Finite Element Method (FEM) using a machine model. It is found in the computed results thatthe mutual interference occurs between the suspension forces in two perpendicular radial axes. The methods to decrease the mutual interference are proposed. The validity proposed control strategy is confirmed through the computed results by FEM.