Reduction of axial force fluctuation of axial flux self-bearing motor using two single-phase stators

Abstract

This paper introduces an axial flux self-bearing motor (AFSBM) using two single-phase stators. The AFSBM controls both bidirectional axial force and motor torque, thus simplifies its structure and control system. However, in the previous test, the axial force fluctuated with the rotational angle, and large vibration appeared at low rotational speed. To solve this problem, a novel stator structure, which slot numbers are increased from four to eight, is discussed. In this paper, the structure and control method of the AFSBM are introduced, and the experimental device is shown. Experimental results show that the proposed structure reduced the fluctuation of the control current at specific rotor angle, however, had no effect in rotational tests.