Abstract

This paper presents the use of hf voltage signal injection for tracking position in an off-the-shelf surface mounted permanent magnet machine. The inherent low saliency of this type of machines presents difficulties and makes the signal conditioning highly critical. In this paper the method of space-modulation profiling (SMP) is used to obtain a magnetic signature of the machine in order to correct for periodic errors in the position signals. Experimental results illustrate the effectiveness of this technique in providing position signals of high quality. These are then exploited to provide closed loop sensorless position control of good bandwidth.