SU1192025A1 - Device for arcing short circuit protection in cells of factory-assembled siwtch-gear - Google Patents

Abstract

DEVICE FOR PROTECTION AGAINST ARC SHORT CIRCUIT IN CIRCLE CELL CELLARS, containing an input switch from a transformer, a section switch, line switches to the load and to the power supply, arc protection circuit breakers embedded in the CIR cells, the first intermediate relay in the winding circuit the parallel-connected contacts of the limit switches are connected, and the contacts of the first intermediate relay are connected in the disconnecting circuit of the input switch from the transformer and the sectional switch, characterized in that Improving operation reliability by increasing speed, additionally a load switch cell, a time relay and a second intermediate relay, the load switch contacts S on the one side are phase-wise connected to KRU buses and shorted on the other side (L contacts of the first intermediate relay are connected to the load switch on circuit and to the winding circuit of the time relay, the contacts of which are connected to the winding of the second intermediate relay, and the contacts of the latter to the circuit of disconnecting the circuit breakers of the g lines to the power sources. . N0 N0 U1

Description

The invention relates to electrical engineering, in particular, to relay protection of electrical equipment, and can be used when protecting complete switchgear 5 devices (KRU) of 6-10 kV indoor and outdoor installations from arc faults.

The aim of the invention is to increase the reliability of operation by increasing the speed.

Fig. 1 is a diagram for connecting the switchgear cells (KRUN) to the busbars of the lower voltage of the downstream station; FIG. 2 is a diagram of operational f: chains.

The transformer 1 is connected via a switch of the input cell 2 to a section of lower voltage busbars, which is connected to an adjacent section by means of a sectional switch on the cell 4 (not shown in figure 1). The busbars are connected to a cell of 5 circuit breakers of the power lines, a cell of 6 circuit breakers, lines running to a synchronous load, a cell of 7 circuit breakers of the power lines, to the rest of the load, and a cell of 8 switches with a short circuit. As a switch 8, a load switch can be used, designed to switch on for short-circuiting without switching it off,

The power supply of the operational circuits (Fig. 2) is provided from an operational source; about the rectified current, which uses stabilized current supply units and

tension

The operating current buses are connected to circuits containing the contacts of the grounding switches for protection against arc faults embedded in the cells, contacts and relay windings, electrical disconnecting and closing switches for the circuit breakers and auxiliary contact blocks of the circuit breakers. In the first circuit, the 9 contacts of the protection switches against arc short circuits of cells 4–8 connected in parallel with each other are connected to the winding of the intermediate relay 10. In the second circuit, ontact 11, relay 10 is connected to the winding of time relay 12. On the third circuit, 55 ontact With a time delay, 13 relays of the belt 12 are connected to the winding of the additional intermediate relay.

14. In the fourth circuit, contact 15 of the intermediate relay 10 is connected via an auxiliary block-contact 16 of the switch 8 of the cell with an electromagnet of the on switch 17 of this switch,. In the fifth circuit, the contact 18 of the intermediate relay 10 through the auxiliary block contact 19 of the switch cell 2 of the input from the transformer is connected to the shut-off electromagnet 20 of this switch. In the sixth circuit, the contact 21 of the intermediate relay 10 is connected via an auxiliary block-contact 22 of the switch of the cell 4 to the shut-off electromagnet 23 of this switch. In the seventh circuit, the contact 24 of the additional intermediate relay 14 is connected through an auxiliary control pin 25 of the circuit breaker 5 to the trip electromagnet 26 of the circuit breaker. In the eighth circuit, the contact 27 of the additional intermediate relay 14. Through the auxiliary blocking switch 28, the switch cell 6 is connected to the shut-off electromagnet 29 of this switch. If there are a larger number of lines leading to the power supply and synchronous load, additional circuits similar to the seventh and eighth circuits are executed (shown in Fig. 2 by dashed lines).

The device works as follows: at once.

In the event of an arc closure in a switch cell of any of the 3 lines departing from busbars in a cell of a 4-section switch or in a cell of a load switch 8, contact 9 of an arc-locked circuit-breaker built-in switch is closed. In this case, the intermediate relay 10 is activated. When the contacts 11,15,18 and 21 of this relay are closed, voltage is applied to time relay 12, the turn-on electromagnet of the load switch 8 via the self-powered contact block 16 of this switch, the electromagnets of the switch disconnectors 2 inputs from transformer 1 and sectional switch 4 through the auxiliary block contacts 19 and 22 of these switches. When the contact closes with the time delay 13 of the time relay 12, the voltage is applied to the winding of the additional intermediate relay 14. With the contact closure of the contacts 24 and 27 of this relay, the voltage is applied to the electromagnets of the disconnecting switches to the power supply and to the synchronous load, through auxiliary block contacts 25 and 28.

In the proposed device, using the load switch 8, an artificial short circuit is created on the busbars of the substation, shunting the place of the arc circuit and thereby eliminating this short circuit without additional deceleration.

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Claims (1)

DEVICE FOR PROTECTION AGAINST SHORT-CIRCUIT ARC IN CIRCUIT BOXES, containing the input switch from the transformer, section switch • • switch, circuit breakers to the load and to the power supply, arc-switch circuit breakers built into the switchgear cubicles, the first intermediate relay, in the winding circuit which includes parallel-connected contacts of the limit switches, and the contacts of the first intermediate relay are connected in the circuit to disconnect the input switch from the transformer and the section switch, characterized in that, in order to to increase the reliability of operation by increasing the speed, an additional load switch cell, a time relay and a second intermediate relay are introduced; the contacts of the load switch _{Q are} phase-connected on the one hand 19 to the switchgear buses and, on the other hand, are shorted, the contacts of the first intermediate relay are connected to the load switch circuit and to the winding circuit of the time relay, the contacts of which are connected to the winding of the second intermediate relay, and the contacts of the latter to the disconnect circuits of the line switches to the power sources. SU <,., 1192025