Motion Control of a Dual-Motor Interior Permanent Magnet Bearingless Machine

The bearingless machine construction is optimal for high-speed machines as it reduces the axial length of the machine. It is crucial that the vibration levels of the rotor are under control during rotation. In the bearingless machine, the rotor is magnetically levitated with an integrated winding system alongside a standard motor winding. In this paper, a control approach is presented to regulate the rotor position in the radial and axial directions together with the speed control of the machine. The rotor vibration levels are verified by rotational tests.