Asynchronous motor based on Active-Disturbance Rejection Controller

A novel approach to speed sensorless vector control system of asynchronous motor based on Active Disturbance Rejection Controller (ADRC) is presented in this paper. In the synchronously rotating reference frame, the equation of magnetizing current is a first order nonlinear state equation. The nonlinear part of the magnetizing current equation includes the rotor speed information, which can be regarded as the disturbance of magnetizing current loop. A speed observer based on ADRC is designed in this paper. The disturbance variation of magnetizing current loop is observed in real time by the ADRC speed observer. The rotor speed is then estimated from the observed disturbance variation. Simulation results show that the rotor speed can be accurately estimated from 10r/min to 1500r/min with load or not. A good dynamic and static performance of the sensorless vector control system is achieved by this method.