| 摘要 |
<P>PROBLEM TO BE SOLVED: To shorten the time required for acceleration when accelerating an induction motor already started and now in a stationary operation state toward a rotational speed higher than the present rotational speed. <P>SOLUTION: In an induction motor driving unit which rotates the multiphase induction motor by outputting the AC voltage of output frequency, which is decided corresponding to the operating speed, from a variable voltage variable frequency inverter device, the inverter device executes a first process of increasing the output voltage more into overvoltage state than usual prior to output when increasing the output frequency into the second frequency set value, and a second process of returning the output voltage into the usual state while keeping the output frequency at a value corresponding to the second frequency set value after that, when accelerating the induction motor by switching the output frequency from a first frequency set value to a second frequency set value determined higher than it during stationary operation. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
