RU6474U1 - ELECTRICAL SUBSTATION - Google Patents

Abstract

An electrical substation containing high voltage power lines, transformers with low-side voltage transformers, distance and zero-sequence current protection on the lines, characterized in that on the power lines distance protection is connected to the transformers of the low side of the transformers, zero-sequence current protection is included with a selective organ current protection.

Description

ELECTRICAL SUBSTATION

The device is intended for use in the energy sector. Such substations are known, see, for example, a substation with a power source and a pin-transformer unit iJ connection diagram.

The line relay protection at the substation is included on the low voltage voltage transformers and the high side current transformers.

As protection against interphase short circuits, distance protection is used, against short circuits on the earth - non-directional current protection of zero sequence.

Such a substation is carried out with one high-voltage power line and this limits its scope

The closest in technical essence is a consumer walk-through substation with two-way power supply, two power transmission lines, power transformers and a bridge circuit with a switch in the jumper and separators from the transformer circuits

Power lines have distance protection connected to high voltage voltage transformers, zero sequence current protection with power direction organs that contain voltage windings also connected to these voltage transformers.

The proposed simplification of the substation consists in the exclusion of voltage transformers. High voltage, in the current protection of the zero sequence of lines - their secondary circuits and voltage windings in the devices.

H 02 B 5 / o

pin protection is achieved by turning them on to the transformers of the low side voltage of the transformers, in current protections of zero sequence - by turning them on with a selective current protection organ.

The selective overcurrent protection device detects damaged impurities by comparing the absolute values of the fault currents in the connections and it does not require voltage transformers.

Figure 1 shows a schematic diagram of the inclusion of distance protection line to the voltage transformer low side of the transformer.

On the rg. I are indicated;

1-d 5-station protection,

2-voltage transformer main power protection,

3-voltage transformer backup power protection,

4-device automatic power backup,

5-disconnecting transformer apparatus-separator,

6-current transformers protection line,

7th power line.

By current, the distance protection of power line I of V is connected to current transformers of the second line, by voltage, the protection resistance relays are connected to phase voltages relative to the zero point of the power system according to known schemes.

The main and backup power supply of the voltage protection circuits are provided.

When disconnecting a transformer with a voltage transformer 2 of the main power supply, the automatic switching device is back

Power Supply (ATS) 4 switches the protection power to

protection of another line from the main power supply from voltage transformer 3 to backup power from voltage transformer 2.

Figure 2 shows a schematic diagram of the inclusion of current protection of a low-speed sequence of lines with a selective organ of current protection of a substation with a connection diagram of a Bridge with a high voltage switch in the jumper and separators in the transformer chains {/

Fig. 3 shows a schematic diagram of the inclusion of current protection of zero sequence of lines with a selective substation organ with a connection diagram of a Bridge with switches in transformer circuits and a repair jumper on the side of transformers 3J.

Figure 4 shows a schematic diagram of the inclusion of current protections of a zero sequence of lines with a selective substation organ with a connection diagram of a Bridge with circuit breakers in the circuit lines and a repair jumper from the side of the pin S,

In FIG. 2,3,4 are indicated:

I- remote line protection,

6,8,14,15,22,23 - current transformers,

7.9 power lines

10.11 - current protection of the zero sequence of lines,

12,13,20,21 - shoulders of a selective organ of current protection,

18.19 - current protection of the zero sequence of transformers or sections, if they are performed, 16 - selective body of current protection,

17- interline repair jumper

As a selective organ of current protection in the circuit of figure 2, a device with two shoulders {5, B circuits of Fig. 3, 4 multi-ring device b.

At the substation, the neutrals of the transformers / one or both / are grounded and they serve as sources of zero-sequence currents during short circuits to ground.

During short-circuiting (short circuit) in KI, the value of short-circuiting current in the damaged line 7 is greater than the current of line 9 due to the neutral currents of the transformers and in the selective body of the current protection 16, the actuator of the shoulder 12 of line 7 is activated and B starts its protection operation 10, which disable switch B.

In the case of short circuit in K-2, the largest value of the current of damage, equal to the current of both lines and the transformer of the adjacent section, in the selective body of the current protection flows in the arm 2 of the transformer, which blocks the line shoulders and their protection remains withdrawn.

If the residual current protection is carried out on transformer connections, arm 20 introduces protection 18 and it trips the fault with the B-I switch.

When short-circuiting on the busbar section in K-3, the greatest value of the fault current flows in the arm 20, which is switched on to the current of all the connections of the section, by which the line arms are blocked and their protection remains withdrawn.

If current protection of the zero sequence of sections is performed, the arm 20 introduces the protection 18 and it disables the damage by switches B and B-I.

In electric networks, at low values of the neutral currents of transformers, when the compared line currents are close in value and the selective organ of current protection helps to be on the verge of sensitivity, its selectivity is provided artificially. For example, by increasing the values of the secondary currents of the neutrals of transformers.

in this case, in the liver of the sedentary organ of the TDB damaged by the dynes, the transfractor neutrality will be artificially removed and in the case of undamaged, it will reduce the TDKOB value and comparing them after this ensures the operation of the last single arm of the shoulder of the sedative organ of the damaged line.

The proposed substations can be used in 110-220kV networks of any configuration.

List of used literature.

I. L.D., Rozhkov, Z.S. Kozuyain Electrical equipment of stations and substations, Moscow, nergoizdat, 1987, rms.5.12a, strL09. 2. Guidelines for burdock protection, and 7, Remote protection dkny 53 - ZZOkV, Energy, Moscow-Leningrad, 1966, fig. 24, p. 65.

3. Typical materials for design 407-03-456.87 Schematic diagrams of electrical distribution ycTpoiicTB voltage 6 ... 750kV substations, Album I, Power grid project, North-West branch, Leningrad, schemes: 1 IIO-3, K: IIO-5AH, K2 IIO-5H.

4.I.F. Maruda Device for automatically switching on the backup power supply of voltage circuits for distance protection of a power line, application for utility model, with 96II85I6 / 20 (024-96), decision to issue a certificate from П-И-ЯСг.

5.I.F. Maruda Device with selectivity of action, certificate for utility model t 3512.

6.I.F. Maruda Selective overcurrent protection, utility model certificate h: 3667.

Claims (1)

An electrical substation containing high voltage power lines, transformers with low-side voltage transformers, distance and zero-sequence current protection on the lines, characterized in that on the power lines distance protection is connected to the transformers of the low side of the transformers, zero-sequence current protection is included with a selective organ current protection.