Single-Phase Suspension Control of Bearingless Switched Reluctance Motor

The article proposes a single-phase suspension control strategy with self-decoupling to address the complexity of decoupling control strategies caused by the coupling between radial suspension forces in two radial directions of bearingless switched reluctance motor (BSRM). The proposed single-phase control strategy aims to achieve stable rotor suspension by adjusting the current of the suspension winding only when one of the torque windings is excited instead of all torque wingdings. A sharing suspension windings bearingless switched reluctance motor (SSW-BSRM) is taken as research objective, the relationship between radial force and radial displacement of rotor with proposed single-phase suspension control strategy in one electrical cycle is analyzed. When the rotor speed exceeds a certain value, the feasibility of switching from three-phase suspension control to single-phase suspension control is theoretically analyzed. The expression of the critical speed of the rotor is derived, which reveals the speed requirement for achieving stable rotor suspension under the proposed single-phase suspension control strategy. The simulation and experiment are carried out on a 12/8 SSW-BSRM, and the results verify the effectiveness of the proposed single-phase control strategy in achieving stabilized rotor suspension with self-decoupling in two radial directions. Furthermore, the proposed control strategy can also be applied to the suspension control of conventional BSRMs.