| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a drive controller and a drive control method for an inverter hoist which are capable of avoiding a drop of a load by a relatively simple operation and capable of performing stable vector control even in the event of a drop of power source voltage or in the event where the output voltage is saturated at a rating speed due to a voltage characteristic of the electric motor. <P>SOLUTION: When the drive controller detects saturation of the output voltage (over-modulation) due to a drop of power supply voltage, it reduces the operation speed of an induction motor 2 by reducing an operation speed command to a frequency at which the required torque can be output. As a result, the drive controller can safely and adequately utilize performance of vector control in all the regions from low-speed to high-speed, without deteriorating functions as a hoist. <P>COPYRIGHT: (C)2012,JPO&INPIT |
