| 摘要 |
PURPOSE:To largely reduce a noise generated from an AC motor by controlling so that a deviation between a drive current supplied to the AC motor and a current command value becomes a value between the prescribed upper and lower limit values. CONSTITUTION:Threshold values having two different hysteresis widths DL, DS are provided above and below a current command value (i) by the operations of two hysteresis comparators 21, 22, and set to become a relationship of the DL, DS. The width DL prevents a deviation between the motor drive current (i) and the current command value i* from excessively increasing to flow more current than required. The width DS prevents the current flowed to the motor 7 from becoming in excess control state, i.e., impossible to generate suitable ''displacement''. |
