摘要 |
FIELD: electricity.SUBSTANCE: device contains a directional element consisting of matching current and voltage converters of transformer type, two frequency filters, two emergency component filters, two current and voltage signs comparator circuits, two univibrators, two inhibit circuits and a starting element consisting of a commercial frequency filter, an inhibit circuit, a voltage relay, AND element, a time element and two output relays, there are also auxiliary inhibit circuit, a commercial frequency filter, two threshold elements, two time elements and two output relays.EFFECT: improving operational reliability of the device at failure of zero-sequence voltage circuits or at non-availability of voltage at the distribution point or at the transformer substation with which zero-sequence voltage circuits can be arranged.1 dwg |