| 摘要 |
PURPOSE: To provide an induction-motor control apparatus by which a rotational speed can be controlled always with good accuracy. CONSTITUTION: An induction-motor control apparatus is provided with a secondary-magnetic-flux estimation device 124 which estimates a d-axis secondary magnetic flux and a q-axis secondary magnetic flux for an induction motor 100. In the induction-motor control apparatus, a speed estimation device A 126 which estimates the rotational speed of the induction motor while an estimation-speed element part A which has been computed on the basis of a d-axis primary current and a d-axis secondary magnetic flux and on the basis of the inherent constant of the induction motor is driven by a q-axis secondary magnetic flux and a speed estimation device B 128 which estimates the rotational speed of the induction motor while an estimation-speed element part B which has been computed on the basis of a q-axis primary current, the q-axis secondary magnetic flux and the inherent constant of the induction motor is divided by the d-axis secondary magnetic flux are changed over by a speed estimation device 130 so as to be controlled. |
