METHOD AND APPARATUS FOR CONTROLLING INDUCTION MOTOR, STEEL AND NONFERROUS EQUIPMENT, RAILWAY VEHICLE, WINDER, SHIP, MACHINE TOOL, PAPER MACHINE, AND CONVEYANCE FACILITIES

摘要

The present invention relates to a control process of an induction motor (1) which makes it possible to produce a high power output. The control process of an induction motor (1) includes the step of performing magnetic field weakening control by using vector control when a magnetic field generated by the induction motor (1) is in a strong magnetic field state, and further includes the steps of increasing an internal induced electromotive force (Ed) in proportion to an increase in a rotational speed (N) of the induction motor (1) in the strong magnetic field state, exercising the magnetic field weakening control when the internal induced electromotive force (Ed) is more than that at a rated rotational speed, and varying the internal induced electromotive force (Ed) to exceed that at the rated rotational speed under the magnetic field weakening control.