Induction motor sensorless vector control for very wide speed range of operation

Vector control or other dynamic control like DTC is an essential feature of every modern AC drive. In this paper a novel robust MRAS-based speed observer based on error between current estimators output and measured current is presented. For being usable in the industry, this has to work properly in wide speed range, from speeds close to zero, up to the speeds deep in the field weakening region. Theoretical analysis of estimators and design of adaptation loop are described. Finally, experimental results are shown.