Fold Angle of Winding Arrangement in Single-Drive Bearingless Motor with Radial Gap

Abstract

A novel single-drive bearingless motor with a high passive stiffness and wide gap factor is proposed. The singledrive bearingless motor has only one set of three-phase windings. It independently generates both the torque and axial suspension force with only one three-phase inverter and one displacement sensor. Therefore, the single-drive bearingless motors have the advantages of low cost and small size. Only the axial direction z-axis is actively positioned. The other axes, the radial movements x and y and the tilting movements θ x and θ y , are passively stabilized by repulsive passive magnetic bearings. The stator consists of six C-shaped cores and one set of three-phase windings. A novel V-shaped winding structure is proposed to simultaneously generate the torque and active axial force. In this paper, the winding arrangement is presented. In addition, the mathematical calculations are presented in this paper.

A research trend of electric machines with development of finite element analysis

“…6. Fold angle of winding arrangement in single-drive bearingless motor with radial gap [16]. The arrows in the windings indicate the positive current direction: (a) winding arrangement with V-shaped structure; (b) V-shaped winding structure from airgap side using a ferrite magnet instead of a rare-earth magnet.…”

“…In order to achieve size reduction, some authors have proposed an integrated winding structure [15,16]. In case of variable-speed drive applications, the conventional separated motor drive system consists of the electric motor, inverter, direct current (DC)-DC boost-up converter, and low voltage battery.…”

“…In Ref. [16], the authors propose a novel single-drive bearingless motor with high passive stiffness and wide gap factor. Figure 6 shows the details of the winding arrangement of the proposed bearingless motor.…”

“…These achievements have been highlighted by many researchers who have proposed novel approaches to improve motor performance. Three groups of topics will be introduced in this paper: optimal design methods [1][2][3][4][5][6][7][8][9], novel motor structures [10][11][12][13][14][15][16], and novel control methods [17][18][19][20].…”