SU1320858A1 - Device for differential protection of double system of common buses - Google Patents

Abstract

The invention relates to the field of electrical engineering - relay protection of electrical installations, in particular to the protection of switchgear with two busbar systems. The purpose of the invention is to increase reliability and simplify the design by avoiding switching in current circuits. The device contains current transformers 7, the secondary windings of which are assembled in accordance with) (a differential circuit and connected to current circuits of the triggering organ 8. The triggering organ controls the tripping circuits of the bus connecting switches 6 and the current output relays 11 and 12. With an external short circuit The protection does not work, since the starting body 8 is rebuilt from the unbalance current. When the short-circuit on any of the bus systems and the simultaneous short-circuit on both bus systems and the absence of a flow on the busbar switch 6, the switch off 6 followed by skadnym disconnecting povredivshihs tires. 1 yl. with

Description

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The invention relates to electrical engineering, in particular, to devices for relay protection of switchgear tires with two busbar systems.

The aim of the invention is to increase reliability and simplify the design. By avoiding switching in current circuits.

The drawing shows a diagram of a device for differential protection of a double busbar system.

The proposed device contains the first 1 and second 2 bus systems to which the switch 5 of the connections and the disconnecting switch 6 are connected via bus disconnectors 3 and 4. The secondary windings of the current transformers 7 of all connections are assembled in a differential circuit and connected to the current circuits of the starting 8 of busbar protection and to the first winding of the power direction relay 9, the second winding of which is connected to the transformer 10 of the bus connecting switch 6. The contacts of the trigger bodies 8 are connected to the disconnecting circuits connecting switch 6, to the coils of the output relays 11 and 12 of the first and second bus systems through the contacts of the relay 9 of the busbar 6 power switch, to the same coils of the output relays 11 and 12 through the contacts of the repeater 13 of the disconnected busbar switch 6 and the corresponding relay contacts , 14 and 15 control voltage disturbances on busbars 2 and 1, connected to them via transformers 1-6 and 17 voltages. The contacts of output relays 11 and 12 are connected to the tripping circuit of the switches 5 through the contacts of the repeater 18 of the position of the bus disconnectors 3 and 4 of the bus systems 1 and 2 "

The proposed device works as follows.

The switches 5 of the respective connections are connected to the busbars 1 and 2 via bus disconnectors 3 and 4, depending on the particular switchgear mode and the adjacent network with the bus coupler 6 turned on, according to the conditions of reliability and economy.

208582

With external k, s, the starting organs of the 8 busbar protection are rebuilt from the unbalance current, so the protection does not work. When k, h. On one of the systems 5, bus 1 or 2, the starting organs 8 from the current to, 3., summed up by the current transformers 7 are triggered with the simultaneous operation of the relay 9 of the power direction of the bus-connecting switch 6 with the closure of its contacts depending on the direction of the current from the current transformers 10 him in relation to the total current of all connections of busbars of the switchgear. When k.z. on the first bus system 1, the circuit is closed on the coil of the output relay 11, and when k, s, on the second bus system 2 - on the coil of the output relay 12,

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The operation of output relays 11 and 12 causes the corresponding disconnection of switches 5 of those connections that are connected to bus system 1 or 2 depending on the opening of the trip circuit through the relay contacts of repeaters 18 bus disconnectors 3 or 4. The bus switch 6 is disconnected directly from the starting opraHoi 8 diffuse protection tires, therefore, only the system of tires is disconnected, on which the k, s ,.

In the modes of the open bus connecting switch 6 in the presence of bypassing connections between the grounded-E bus systems 1 or 2. The selection of the damaged bus system is carried out with the help of relay 1 - and 15 monitoring the voltage disturbance on the busbars by choosing the setpoint rebuilt from .-з, on a foreign bus system through by-pass communications with an intact tire system. Since the difference

 The voltage level due to the circulation of the GOKS through the communication lines is significant5 the selectivity of the protection effect is maintained by closing the circuit to the output coils

relays 11 and 12 through the contacts of the relay 15 or 14 of the voltage control on busbars 1 or 2 to the starting bodies 8 when the contact of the repeater relay 13 is closed and the bus connection switch 6 is off. To control the voltage level on busbars 1 and 2 the corresponding relays 15 and 14 are fed through the NON-breaker voltage transformers 17 and 16.

in the case of simultaneous k, e. On both bus systems and the absence of a flow through the bus connection of the switch 6 from the triggering bodies 8, it is disconnected with the subsequent cascade disconnection of damaged bus systems from the relay 14 and 15 controlling the voltage disturbance on the busbars. If there is a flow through the bus connection switch 6, the bus system 1 and 2, where the power direction relay 9 was not oriented, is disconnected, also occurs in a cascade from the corresponding relay 15 or 14 after the bus connection switch 6 is disconnected.

As a power direction relay 9, through a bus coupler 6, a current-polarized relay is used, and for the relay 14 and 15 of the voltage fault control on the busbars, an interfacial voltage control circuit through the voltage relay contacts back or another control circuit can be used violation of the voltage level caused by any kind of short-circuit. on the corresponding bus system 1 or 2.

Claims (1)

Formula of about b reet e n and A device for the differential protection of a double system of prefabricated shkn containing a current transformer installed on all connections of these tires and on the bus connection circuit breaker, secondary windings trans Editor L. Povkhan Order 2664/54 Circulation 618. Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab, 4/5 Production and printing company, Uzhgorod, Projecto st., 4 ten 0, f5 2085S. four current formers installed on the connections assembled in a differential circuit connected to the starting body associated with the first and second groups of output relays connected to the disconnecting circuits of the connection switches via the relay follower bus disconnectors of these switches and connected to the disconnect switchgear busbar switch, characterized in that, in order to increase reliability and simplify the design by avoiding switching in current circuits, directional relays are additionally introduced For example, a relay repeater of a disconnected position of a busbar switch and the first and second voltage reducing control units, respectively, on the first and second bus systems; the first winding of the power relay is connected to the differential circuit of the secondary windings of the current transformers, the second winding is connected to the secondary winding current transformer bus-disconnecting switch, power relay contacts are connected between the output of the starting organ on two groups of output-relays, through the trigger circuit through the relay contacts The repeater is disconnected for the busbar connection. The switch is connected to the first and second groups of output relays 35 via the first and second control units of the voltage reduction, respectively. 3t Compiled by A. Bondarenko Tehred V. Kadar Proofreader M. Pojo