| 摘要 |
PURPOSE:To supply stable power to a plurality of loads, by phase-controlling the main thyristor which constitutes a feeder interrupter. CONSTITUTION:The load current is detected by a meter current-transformer CT and an overcurrent signal S1 is produced by a comparator 11, and a pulse generating circuit 12a supplies a turn-on pulse to a thyristor SCR 3. An operation signal S2 from an operation-stop control circuit 10 and the signal S1 are coupled to an OR-circuit 15a, whose output is supplied to a soft-start circuit 17 and to a timer circuit 16. The outputs of an ACR control circuit 18 and the circuit 17 are supplied to a control-angle determining circuit 19, whose output is supplied to a pulse generating circuit 12b for producing a turn-on pulse to a thyristor SCR 1. The pulse generating circuit produces a pulse when the operating condition that (S3+S4) S2 (inverted S1) = 1 is satisfied by S1, S2, an output S4 from a zero-discriminating circuit 20 for control-angle, and an output S3 of the circuit 16, besides realization of the appropriate voltage polarity on the inverter side. |
