Control circuit topology of a time-divided torque and suspension force control type bearingless motor

This paper presents a new control circuit topology of the time-divided torque and suspension force control type bearingless motor. The motor structure, its principle of suspension force and rotational torque generation has been introduced. The proposed control circuit and its sequence of operation are explained in detail. In the new control circuit topology, the surge voltages which are applied in the switching devices are successfully suppressed. It is confirmed by the simulated results of the control circuit that the applied voltages in these devices are significantly reduced. The proposed control circuit topology is found effective to drive the time-divided type BELM.