The levitation of the SIXEP pump shaft using active magnetic bearings

The design of electromagnetic bearings for use in a radioactive environment is presented specifically from a control point of view and supported by experimental results. A pump shaft 2 meters long, weighing 110 kg, is levitated by such bearings and driven by an induction motor capable of spinning at variable speeds of up to 3000 rpm. The experimental results demonstrate that this bearing system is stable and robust when the shaft is run through its two critical speeds.