The flux observer and speed identification based on closed-loop extended state observer

Flux observer and speed identification are key issues in the induction motor speed sensor-less vector control system, and these two issues are linked. We can use the observer result we get from the estimate system to the object whose structure is certain and the model is linear to some unknown parameters, we will get a closed-loop extended state observer. So we can reduce the uncertainty and improve the accuracy. The result of parameter identification based on the closed -loop ESO is convergent. Therefore, we can get the flux and the speed of induction motor accurately and quickly through the model reference adaptive system. The closed-loop ESO is the adjustable model of MRAS.