| Abstract |
The paper presents some theoretical problems concerning vector control of the induction motor stator current, at constant rotor flux. In this way, a stator current component is constant. It results a better dynamic response, with a simpler control diagram, because the input values determine without delay the torque. The identical structure of the speed loop, for both a current controlled induction motor and a d.c. one with independent excitation is rendered evident. Experimental results are also presented, obtained with induction motor drive, using sinusoidal control of the stator current. The vector control has been obtained in two versions: a digital and an analog one. With both versions a control range of 1 : 10(4) has been obtained. The dynamic response, at low signals, including low speed, and low speed reversal is similar to a d.c. motor drive. Such performances make it possible to be used in the field of feed and spindle drives for machine-tools. |
