Sensorless Control of a Three Phase Radial Active Magnetic Bearing

This paper presents results of a three phase radial active magnetic bearing architecture combined with a sensorless position control algorithm. Therefore the three coil bearing structure is utilized by a three phase voltage source drive inverter. To reduce bias current consumption permanent magnet bias fluxing is used and iron losses are reduced by gaining homopolar architecture. The sensorless position detection algorithm and the control architecture are presented. Experimental results confirm the sensorless concept by measurements and quality measures for the sensorless method are investigated to show the limits of operation.