| 摘要 |
A control arrangement for rolling stock driven by a separately excited d.c. motor comprises a field chopper for controlling the motor field current and a field switch for switching the field current direction. The field chopper is controlled by a field chopper control circuit 26 and the field switch by a control circuit 27. To avoid a high voltage transient voltage being generated when field current is interrupted during regenerative braking, the control is arranged to maintain operation of the field switch for a predetermined time delay following stopping of operation of the field chopper, whereby the field current can decrease relatively gradually. <IMAGE> |
