Abstract: Aiming at many defects of the traditional speed sensorless vector control system of asynchronous motor
based on rotor flux linkage, such as serious overshoot, weak robustness and poor load capacity, our object is to
improve the traditional speed sensorless model of asynchronous motor. The speed PI ( Proportion Integration)
regulator in the traditional speed sensorless model of asynchronous motor is combined with the neural network
adaptive control algorithm, and a third-order low-pass filter is added to the current model of rotor flux linkage.
The simulation analysis is carried out for the start-up of asynchronous motor, the speed torque and the change of
estimated speed after sudden load increase. Experiments show that the improved speed sensorless vector control
system of asynchronous motor obviously eliminates the overshoot, effectively improves the robustness of the system
and enhances the load capacity of asynchronous motor.

Key words: vector control; , asynchronous motor; , speed estimation; , model reference adaptation; , rotor flux orientation