A Novel Stator Resistance Identification for Speed Sensorless Induction Motor Drives Using Observer

This paper designs a full-order adaptive observer and proposes adaptive identification laws for speed and stator resistance based on the proposed observer. By using the theory of Lyapunov stability, the gain of the observer can be obtained by solving two bilinear matrix inequalities using the LMI toolbox of MATLAB, which solves the problem of the unstable region in theory and the inaccurate estimation of speed, and it also reduces the effects of the stator resistance varying. The simulation model of speed sensorless induction motor using direct torque control is built in the Matlab6.5/Simulink and the result of simulation indicates that the adaptive observer has good steady-state and dynamic performance and good robustness