A Novel Mechanical Sensorless Control for PMSM Tolerant to Stator Resistance Uncertainties

It is known that mechanical sensorless control of PMSM is sensitive to the stator resistance uncertainties. In this paper, the influence of these uncertainties on the sensorless control is studied and a simple method improving the control performances is proposed. This method consists in imposing a proportional relationship between the stator current components. It makes the sensorless control law independent from the resistance uncertainties permitting successful start-up and speed inversion without on-line resistance estimation. The experimental results show the validity and the efficiency of this approach.