PL149696B1 - Protection circuit for protecting switchboard buses - Google Patents

Description

PATENT DESCRIPTION

149 696

OFFICE

PATENT

PRL

Additional patent to patent no. Applied for: 85 04 15 / p. 252923 /

Priority

Application announced: ⁸⁶ 10 21 Patent specification published: 90 04 30

Int. Cl. ⁴ H02H 7/22

CL i i tLNIA

Patent Office flfMtti Ihpwti

Creators of the invention: Kazimierz Kabaciński, Wacław Rankiewicz

The holder of the patent: Biuro Studiów i Projektów Energetycznych Energoprojekt, Poznań / Poland /

DISTRIBUTION RAIL PROTECTION SYSTEM

The subject of the invention is a protection system for switchgear busbars, which quickly disconnects the power supply of a short circuit within the busbars

They are known from the typification of the symbol T-3608 volume VIII / 1, Redakcja III, version B of January 1980, published by the Energoproj ekt Energy Studies and Projects Office in Poznań, rail protection systems, in which the connection between the overcurrent actuating relay bus protection, and the time relay, which implements the delay in the operation of the bus protection, is the contact of the auxiliary relay, which blocks the operation of the busbar protection, when the short circuit occurred outside the busbars. The winding of the auxiliary blocking relay is connected to the overcurrent protections of the outgoing bays of medium voltage switchgears.

The time relay, implementing the delay in the operation of the bus protection, has instantaneous closing connections connected to the time relay, installed in the rail connector bay and realizing the unblocking of the short-circuit operation of the rail connector protection. The time relay, implementing the delay in the operation of the bus protection, has the connection closed with a set delay. to the power cut-off circuit

There is also a known rail protection system used in Zakład Energetyczny Gliwice, in which the auxiliary voltage supply circuit of the over-speed protection installed in the power supply circuit of the switchgear includes an auxiliary relay contact, and the winding of this relay is connected to the overcurrent protection of outgoing bays. . The instantaneously closing contacts of the over-speed protection are connected: one to the opening circuit of the busbar connector, and the other, through a contact closed when the circuit breaker is open, to the circuit of switching off the power supply of the switchgear. The delayed closing contact of this relay is also connected to the switching off circuit of the switchgear.

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These known systems suffer from the disadvantage of being too slow to operate due to the use of a fault clearing delay to maintain the bus protection operation selection, or the inability to selectively open only the rail connector during faults following it

The aim of the invention is to develop such a protection system for switchgear busbars, which would ensure quick and selective disconnection of short-circuits within the busbars, regardless of the current supply system of the switchgear and where the short-circuit will arise.

This object is achieved by the use of the system according to the invention, in which the short-circuit protection installed in the supply circuit has an executive relay winding connected to the overcurrent protections of the outgoing fields from the switchgear busbars, and the instantaneously closed contacts of its current members are connected through the contact of its executive relay to the time relays. realizing a slight delay needed for the correct operation of the busbar protection The output circuit of the faster-acting time relay is connected to the change-over contact of the auxiliary relay, the winding of which, together with the off-delayed relay winding, is connected to the instantaneously closed contacts of the current elements of the short-circuit-current protection of the rail connector The NO contact of this changeover contact is connected to the opening circuit of the rail connector, and the break contact of this contact is connected to the break contact of the relay delayed by dropping and on to the switchgear power off circuit · The output circuit of the slower-acting timer is connected to the switchgear power off circuit ·

The subject of the invention has been shown in the embodiment shown in the drawing, which shows a diagram of a system according to the invention.

In the protection system, the diagram of which is shown in the drawing, the short-circuit-current element of protection 1, installed in the power supply circuit of the switchgear 2, has its operational relay winding 3 connected to the overcurrent protections of 4 outgoing bays 5 from the switchgear busbars 6, and the contacts 7 are closed immediately of the short-circuit module of protection 1 has connected, through the contact 8 of its operational relay 3, to the timing relays 9 and 10, which implement a slight delay necessary for the correct operation of the protection of the busbars. Bb the output circuit 11 of the faster-acting time relay 9 is connected to the changeover contact 12 of the auxiliary relay 13, the winding of which, together with the off-delay relay winding 14, is connected to the instantaneous closing contacts 15 of the starting members 16 of the short-circuit protection of the busbar switch 17 Short-circuit contact 18 of the changeover contact of the auxiliary relay 13 is connected to the circuit opening 19 of the rail connector 17, and the break contact 20 of this contact is connected to the break contact 21 of the off-delay relay 14 and further to the power cut-off circuit 22 of the switchgear 2 The output circuit 23 of the slower-acting timer 10 is connected to the power cut-off circuit 22 switchgear 2

Claims (1)

Patent claim A protection system for switchgear busbars, in which the short-circuit-current protection installed in the switchgear power supply circuit has an executive relay winding connected to the overcurrent protections of outgoing bays from the switchgear busbars, and the immediately closed contacts of its starting members are connected to the time relays through the executive relay contact, characterized in that the output circuit / 11 / of the faster-acting timer / 9 / is connected to a changeover contact / 12 / of the auxiliary relay / 13 /, the windings of which, together with the off-delay relay winding / 14 /, is connected to instantaneous closing contacts / 15 / starting members / 16 / short-circuit-current protection of the rail connector / 17 /, and the contact / 18 / of the changeover contact of the auxiliary relay / 13 / is connected to the opening circuit / 19 / rail connector / 17 /, while the break contact / 20 / of this changeover contact It is connected with a break contact / 2 1 / off-delayed relay / 14 / and further with the switch-off / 22 / switchgear power supply circuit / 2 /, as well as the output circuit / 23 / of the slower-acting time relay / 10 /, is connected to the / 22 / switch-off power supply circuit / 2 /. 149 696 1 23 11 ϊό \ S / W ΙΟ