Effects of Permanent-Magnet Passive Magnetic Bearing on a Two-Axis Actively Regulated Low-Speed Bearingless Motor

Performance comparisons in a bearingless motor with and without passive magnetic bearings (PMBs) are presented. The bearingless motor is actively controlled in two perpendicular-axes. The axial and conical movements are supported by PMBs. The experimental results are compared to the calculated ones by 3-D finite-element method. Effectiveness of PMBs is analytically and experimentally investigated in both static and dynamic tests. It is found that a rotational test is successful only with the PMBs.