| 摘要 |
PURPOSE:To prevent a detrimental transient phenomenon of a motor by detecting the deviation between the electromotive force of the motor and the prescribed reference value and adding a control for correcting the slip frequency according to the deviation, thereby eliminating the influence of the temperature variation in the secondary resistor. CONSTITUTION:A speed command value is compared with the feedback signal of a rotating speed of an induction motor, thereby obtaining a torque current Igamma and an exciting current IE, a current IM, a phase thetagamma , and a slip frequency omegaS are calculated by a circuit 4-3, thereby controlling an induction motor. At this time, the signal of the detector 10 for detecting the electromotive force Em is compared with the set command electromotive force Em', the resistance R2' corrected with the secondary resistance R2 is calculated by a circuir 12, is then multiplied by the slip frequency omegaS, is then added to a rotating speed feedback signal omegam, and the result is applied to the motor. Accordingly, since the slip frequency is corrected continuously until the deviation between the electromotive force of the motor and the command electromotive force becomes the prescribed value, it does not sensitively respond to the small detected error, thereby stably controlling the motor. |
