A Method of Speed Adaptive Estimation Based on Stator Flux U-N Model of IM

Deals with the problem of model reference adaptive speed estimation. The state equation of induction motor with Γ-type parameters was established and a flux observer was designed based on U-N model. The speed adaptive law was deduced by the theory of Lyapunov stability. A method of model reference adaptive speed estimation based on the full order flux observer was proposed and a scheme of induction motor direct torque control without speed sensor was studied. The Matlab simulation model of this scheme was established and analyzed. Also some experiments were implemented in the experimental device of traction motor. Finally, the Matlab simulation and experimental results were given. These simulation and experimental results show that the estimated speed can accurately track the actual speed. These prove the validity and practicability of the method of speed adaptive estimation based on stator flux U-N model proposed by this paper.