Speed sensorless vector torque control of induction machines using a two-time-scale approach

H. Hofmann, S.R. Sanders
IAS '96. Conference Record of the 1996 IEEE Industry Applications Conference Thirty-First IAS Annual Meeting  
Abstract| Conditions for observability of a linearized smoothairgap induction machine model are examined, and limitations of any speed-sensorless observer scheme based on such a model are discussed. An approach for speed-sensorless ux estimation based on two-time-scale theory is developed. This approach relies on the natural time-scale separation between the electrical and mechanical dynamics of the induction machine. A full-order observer of an induction machine is presented, incorporating a
more » ... , incorporating a correction term which has an intuitive explanation when one considers steady-state stator currents. Using singular perturbation theory, convergence of the observer is shown for all open-loop stable operating points of the induction machine with the exception of DC excitation. Sensitivity of the observer to parameter deviations is discussed. Experimental results are presented conrming the validity of the above approach.
doi:10.1109/ias.1996.557016 fatcat:jx2iqkfgbnat3g5b3aklflzkli