A Speed Estimation Method for Induction Motors Based on Active Disturbance Rejection Observer

A speed estimation method for induction motors (IMs) based on active disturbance rejection observer (ADRO) is proposed in this article, in order to realize the sensor-less control of IMs. Benefit from the antidisturbance mechanism of ADRO, the exogenous disturbance can be estimated instantaneously, so that ADRO can realize the disturbance estimation accurately without the knowledge of the exact system parameters. Meanwhile, ADRO copes with the unmodeling dynamics as well as the system uncertainties in the model parameters, so that it is robust to the external disturbances and the model errors. Meanwhile, the disturbance including the rotor speed information is estimated online by ADRO, and the rotor speed is estimated from the observed disturbance variation. The experimental results indicate that the speed estimation is feasible and effective.