Control characteristics of 8/10 and 12/14 bearingless switched reluctance motor

In this paper, two novel bearingless switched reluctance motors (BLSRMs), 8/10 hybrid type and 12/14 hybrid type, are presented. The two BLSRMs have separate torque and suspending force poles. Due to the independent characteristics between the torque and suspending force, the torque control can be decoupled from the suspending force control. In this paper, suspending force control characteristics of the two hybrid BLSRMs are compared. Although the two hybrid BLSRMs have excellent decoupling characteristics, the suspending force control performance is dependent on the torque characteristics. In the suspending force control comparison, a simple PID and hysteresis current control methods are employed. To verify the validity of the control strategy, tests are executed to the two types, and the control characteristics of the two types are presented and compared.