Sensitivity investigation of a speed sensorless induction motor drive based on stator flux vector control

A speed sensorless induction motor drive control scheme, which utilises the stator flux components as control variables, is analysed in this paper. The stator flux is estimated by a closed loop scheme using the flux reference, the stator current vector and the voltage vector as input variables. In order to examine the effects of parameter deviations on the drive performance, the equations of the whole system are linearised at a steady-state operating point. The stability of the control system is verified and the sensitivity of the control scheme, with respect to stator parameter deviations and current sensor offsets, is analysed. Numerical and experimental results are given to confirm the theoretical analysis carried out.