Magnetic levitation tests of a bearingless motor based on d-q axis current control

This paper presents magnetic levitation test results of a bearingless motor (BELM) based on d-q axis current control. The BELM based on d-q current control has been proposed by the authors. The stator winding arrangement and the control method have been conducted in detail. The rotational torque and the suspension force can be controlled by only one kind of stator winding. Hence, the winding arrangement is quite simple and the densities of the torque and suspension force are significantly larger than that of the conventional BELM with two kinds of windings. The validity of its control method has been confirmed by the simulation using Finite Element Method (FEM). In this paper, a prototype machine of the proposed BELM is build and the rotor levitation tests are carried out. The stable rotor levitation is confirmed by the magnetic levitation tests under static and rotational conditions, the rotor acceleration test and disturbance suppression response. The proposed control method is verified by these experimental results.