| 摘要 |
PURPOSE:To change over power travelling and regeneration positively for a short time by mounting a switch discharging an integral capacitor to a current control circuit computing the rate of flowing in response to the amount of deviation between a command of armature currents and an actual value. CONSTITUTION:A current control circuit 50 which compares a command of armature currents set by means of a setter 35 and an actual value detected by a detecting resistor 6 and computes the rate of flowing of a thyristor-stack 3 in response to the degrees of the change of the amount of the deviation has an operational amplifier 51, an integral capacitor 52 and an analog switch 53 controlled by means of a gate selector 42. The integral capacitor 52 is discharged for a short time at a moment when armature currents reach to zero when forward turn power traveling is changed over to forward turn regeneration. Thus, power traveling and regeneration can be changed over for a very short time, the overshoot of armature currents is positively inhibited and the generation of malfunction and trouble can be eliminated. |
