| 摘要 |
PURPOSE:To enable to accelerate an electric rolling stock by starting an inverter, and forcibly decreasing the frequency of the inverter even when the rising rate of the rotating frequency of an induction motor is delayed on an ascent or the like, thereby rapidly increasing the torque. CONSTITUTION:When an inverter start command signal 10 is inputted, the value added with the slip frequency 12 at the starting time to the rotating frequency FR11 of an induction motor at the starting time is held as a starting time inverter frequency FIP15 by switching a switch 13 from ''0'' to ''1''. At this time, when any of an ascent slope detection signal 23, a high acceleration command signal 24 and a retard detection signal 5 is inputted, a switch 22 is switched to ''1''. The value subtracted by the starting time frequency reduced value 27 from the value of the initial FIP is used as new FIP value. When the initial FIP1 gradually decreases to that FXP of the sum of the FR and a reference slip frequency FS1 is judged by a comparator 17 to be FXP>=FIP1, a switch 19 is switched to ''1'', and the FIP is switched to the FXP in the inverter frequency 18. |
