| 摘要 |
PROBLEM TO BE SOLVED: To stably start a bucket elevator of a continuous unloader to discharge the load from a ship hold. SOLUTION: A continuous unloader includes a bucket elevator which scrapes the load in a ship hold and discharges by driving a chain fitted with buckets by a drive sprocket, whereto two induction motors are coupled through respective speed reducers, and these are vector controlled by converting into torque current and magnetic flux on the basis of the primary side current and voltage of each induction motor 32AF by their respective drive circuits 34A and 34B, wherein at the time of starting, the primary current ID1 when a DC low voltage VD is impressed on the induction motor 32AF is sensed, and the primary side resistance r1 is measured, and the primary side voltage in dropping is corrected on the basis of the measurements so as to remove the influence of changing primary resistance at the time of speed control.
|
