Busbar protection device for electric station in 4 / 3 scheme with nine connections

Abstract

The invention relates to electrical engineering, specifically relay protection, and can be used as a busbar protection device for power plants in a 4 / 3 configuration with nine connections. The technical result is to prevent unit shutdown and complete power plant shutdown in the event of a short circuit on the busbar, when the busbar protection is triggered but the busbar circuit breaker and the adjacent circuit breaker fail, thereby preventing the power plant from shutting down. A device for protecting the busbars of an electric power station in a 4 / 3 scheme with first and second buses, between which three chains are connected, each with a first, second, third and fourth switch, connected in series, where the first switches are connected to the first busbar, and the fourth to the second, and between the first and second switches of the extreme left and right chains the first and second power transmission lines are connected, respectively, between the third and fourth switches the third and fourth power transmission lines, between the second and third switches the first and second generator-transformer units, and in the middle chain between the first and second switches an autotransformer is connected, between the second and third the fifth line, between the third and fourth - the third generator-transformer unit, contains a series-connected measuring element, a logic unit and a relay with four contacts, three of which are connected to the trip coils of the first switches, the relay of the "On" positions of these and the second switches, Output relays for the primary circuit breaker and control bus failure backup devices, three four-input AND gates, the output of each of which is connected via a time relay to the corresponding output relay, the first, second, third, fourth, fifth, and sixth intermediate relays with normally-closed contacts with a time delay upon failure and normally-open contacts, three pushbuttons, and six signal lamps. Economic benefit: a large number of consumers will not lose power.