A Method of Speed-sensorless Control of Induction Motor Based on MRAS

In view of problem that traditional speed identification algorithm of induction motor only indentifies motor speed but does not consider influence of change of stator resistance on identification of motor speed, the paper proposed an improved method of speed-sensorless control of induction motor based on MARS. The method respectively uses output of voltage model and current model as expected value and estimating value of rotor flux and stator resistance, then according to MARS theory, it takes voltage model as reference model and current model as self-adaptive and adjustable model to indentify motor speed and stator resistance. The simulation result showed that the method can indentify motor speed and stator resistance simultaneously, which eliminates influence of change of stator resistance on identification of motor speed and improves low-speed identification performance of induction motor control system.