Model reference adaptive vector control of asynchronous motor without speed sensor

Abstract

In order to improve the stability and control precision of asynchronous motor without speed sensor, a new vector control method for model reference adaptive identification of motor speed is proposed. Firstly, the mathematical model of asynchronous motor is set up, and the asynchronous motor vector controller is designed; Secondly, to solve the problem of speed feedback in vector control system, a kind of speed identification method based on model reference adaptive system is presented, and its stability is proved by Popov super stability theory; Further, the effect on speed identification caused by zero drift and integral initial value when the motor is operating at low speed is eliminated by using a low-pass filter instead of pure integrator in voltage reference model, and at the same time, the precision of speed identification is enhanced; Finally, the simulation of asynchronous motor speed sensorless vector control is carried out. The result of simulation demonstrates that the asynchronous motor can track the speed control command accurately, which verifies the precision of the motor speed identification based on MRAS without speed sensor.