| 摘要 |
<p>PURPOSE:To prevent a motor from flowing an overcurrent by setting a chopper conduction rate to zero at disconnecting time, and gradually increasing a motor current from zero to the prescribed value with a delay time at reconnecting time. CONSTITUTION:When a pantograph is disconnected so that the voltage VC of a filter capacitor 4 arrives at the lower threshold value of a comparator 27, switches 22, 24 are switched to L side to set a current command value IC to 0, and a chopper conduction rate alpha also becomes 0. After a short time, the pantograph is reconnected, and when the voltage VC arrives at the upper threshold value of the comparator 27, the switches 22, 24 are switched to H side after the prescribed time limit from this time. Thus, the value IC rises from 0 to the primary delay represented by the primary delay circuit 23. thus, the overshoot of the filter capacitor voltage at reconnecting time can be suppressed.</p> |
