Speed sensorless vector control oflnduction motor based on adaptive full-order flux observer

Abstract

In order to improve the flux aberration and running characteristics of induction motor at low speed region, this paper proposes a design of a new speed-adaptive flux observer based on a model reference self-adaptive system theory (MRAS). It collocated full-order flux observer poles by means of choosing a gain matrix. The observer uses the stator current and stator flux as state variables and combines flux observation with speed estimating by using the speed adaptive law. It was used in the speed sensorless vector control of induction motor. It is shown that the observer using the proposed speed-adaptation law can make sure that the system has better characteristic in the low speed and the effect of erroneous parameter estimations on the accuracy of the observer is comparatively small. Simulation results demonstrate the effectiveness of the adaptive full-order flux observer, and prove the robustness of the system to motor parameters variation.