Suspension Characteristics Measurement of a Bearingless Motor

Bearingless PM motors which have additional suspension windings have been designed with 3D FEM. To verify satisfactions in practical application, a test machine has been built. In this paper, suspension force is measured with the static forces. Two experimental methods are proposed. It is proved that those procedures are suitable even if it is in limited conditions, only one shaft end can be used for static force applied. Furthermore, the relation of the suspension force and rotor rotational angle is shown.