Rotor Flux Observer Based on Close Loop Extended State Observer

The variations of rotor resistance degrade the accuracy of rotor flux observer.A novel rotor flux observer based on the close loop extended state observer(ESO)method is proposed.The uncertainty partition of current model and voltage model is separated from the known models and extended to a new state.This observer compensate the observing value of rotor flux into the known models,which composes a closed loop rotor observer and improves the convergence speed and approximation precision of the extended state observer.Simulation results at both high and low motor speeds illustrate the accuracy and robustness of our proposed method.