GB1285218A - Arc-free heavy-duty circuit-breaker - Google Patents

Abstract

1285218 Arcing preventing in switches; heavy current switches LICENTIA PATENTVERWALTUNGS GmbH 14 Nov 1969 [15 Nov 1968] 55932/69 Heading HlN An arc-free heavy-duty switch includes a mechanical switch connected in parallel with a plurality of anti-parallel connected pairs of thyristors 1-n arranged in series, the switch closing later and opening earlier than the thyristors, the switch including a plurality of contact gaps 1<SP>1</SP>-n<SP>1</SP>, connected in series, with crossconnections a to the series connections of the thyristor pairs 1-n. S is a disconnecting switch and b are voltage-controlling loads. A control St supplies the opening and closing instructions for 1-n, 1<SP>1</SP>-n<SP>1 </SP>and S. It receives its "on" and "off" instructions by hand or from an electronic computer controlling and monitoring the mains automatically. Structurally the mechanical contacts and thyristors are mounted in a column of hard paper or porcelain filled with SF 6 , and contact actuation is by pressure gas or an insulated cam or eccentric shaft, normally in synchronism with the mains. The contacts and thyristors may work under vacuum, or an insulating liquid, or gas at increased pressure. The thyristors remain constantly turned on by suitable resistors or inductors so that, on contact opening, they can take over their current quickly. In the event of a short-circuit, a maximum of only one half-wave of the short-circuit current occurs. Reference is made to suitable voltage control by resistors or capacitors. A saturable stepped reactor may be used in series with the thyristors to facilitate circuit closing.