Analysis of Rotor Acceleration Speed and Vibrations in a High-Speed Single-Drive Bearingless Motor

The use of bearingless motors with a controlling one-axis active position has been explored for a variety of industrial purposes, such as cooling fans and pumps. The advantage of these motors is that they have a straightforward control system, since only one set of the three-phase inverters is necessary to produce both the active magnetic suspension force in the axial direction and the rotating motor torque simultaneously. However, the acceleration speed up to high-speed regions has not been extensively studied. This study investigates the rotor vibrations of a single-drive bearingless motor when it is accelerated to a high-speed region. According to the simulation results, in both low and high accelerations, the motor can achieve an acceleration speed of up to 60 000 r/min without any touchdown in the radial and inclining direction of the range of +/- 1.5 mm and +/- 80 mard, respectively. In high acceleration, the rotor maximum vibrations is only +/- 0.1 mm and +/- 0.3 mrad, in the radial displacement and inclining movement, respectively.