Low-speed Performance Research of Induction Motor Based on New Speed Adaptive Method

At traditional induction motor drive system of speed-sensorless vector controlled, the error of estimated speed was obvious in low speed. To solve this problem, a new speed adaptive algorithm was designed. The traditional adaptive algorithm was improved, the compensation amount equivalent to the flux error caused by the nonlinear voltage error of the inverter and the voltage drop of the stator resistance was added on the basis of the traditional speed adaptive algorithm, and this compensation differently as the speed changes. The accuracy of speed estimation at low speed was improved without affecting the stability of the whole system. The validity of the algorithm is proved by experiments. Experimental waveforms prove that the algorithm proposed in this paper can ensure the motor running stably at low speed with rated load.