CN202178610U - Switching apparatus of bypass switch for operating TA secondary circuit in replace of main transformer - Google Patents

Abstract

The utility model discloses a switching device for a bypass switch to operate a TA secondary circuit on behalf of a main transformer, comprising: a common connecting wire group, a plurality of main transformer connecting wire groups, a first conductive connecting piece and a second conductive connecting piece; the common connecting wire One end of each common connecting wire of the group is connected to the TA secondary circuit, and the first conductive connecting piece connects and grounds each common connecting wire; one end of each main transformer connecting wire of each main transformer connecting wire group is connected to the common connecting wire One end of each common connection line of the group is connected one by one, and the other end of each main transformer connection line of each main transformer connection line group is connected to the main transformer protection screen; each main transformer connection line group is connected to a main transformer protection panel. screen; each main transformer connecting wire group is provided with a second conductive connecting piece on each main transformer connecting wire group, and one main transformer connecting wire in each main transformer connecting wire group is grounded. By adopting the utility model to configure the TA secondary winding, the protection dead zone can be eliminated, the cost can be reduced, and the economic benefit can be improved.

Description

The bypass switch replaces the main transformer to run the switching device of the TA secondary circuit

technical field

The utility model relates to the protection field of a power grid power supply system, in particular to a switching device for a bypass switch operating a TA secondary circuit instead of a main transformer. the

Background technique

In the power grid power supply system, in order to avoid power failure of the line or transformer when the circuit breaker is overhauled, in my country's power grid, the 220KV side and 110KV side of the 220KV substation generally adopt the main wiring mode of double busbars with bypass. However, the 220KV main transformer protection currently in operation generally adopts a dual protection of a large differential protection and a small differential protection. As shown in Figure 1, PM represents the bypass bus; 1M represents the first section of bus; 2M represents the second section of bus; PDL represents the bypass switch; DL represents the main transformer switch; PM busbar isolation knife; 1G, 2G, 3G, 4G respectively represent main transformer 1M, 2M, 3M busbar isolation knife and outlet knife; LH means current transformer; on the switch side of the main transformer, 1LH P level is used for main transformer large difference protection, 2LH P level for busbar protection 1, 3LH P level for busbar protection 2, 4LH P level for failure, wave recording, etc.; 5LH P level for measurement, 6LH P level for measurement; on the side of the bypass switch, 1LH P level for line protection 1 , 2LH P level for line protection 2, 3LHP level for busbar protection 1, 4LHP P level for busbar protection 2; 5LH P level for failure, wave recording, etc., 6LH P level for instrumentation; 9LH P level for main transformer small differential protection ; B represents the main variable. the

When the main transformer switch is overhauled and the bypass switch needs to be used to replace the operation, it is generally necessary to withdraw the large difference from the operation, resulting in the loss of fast protection between the bypass switch current transformer (TA) and the high-voltage side bushing TA of the main transformer, and a protection dead zone occurs. . The existence of this dead zone may cause a power outage throughout the station, resulting in a large-scale power outage or even damage to the stability of the power grid. the

Utility model content

The utility model proposes a switching device for the bypass switch to operate the TA secondary circuit on behalf of the main transformer, which can eliminate the protection dead zone, reduce costs and improve economic benefits. the

The bypass switch replaces the switching device of the main transformer to run the TA secondary circuit, including: a common connection line group, a plurality of main transformer connection line groups, a first conductive connection piece and a second conductive connection piece; each of the public connection line groups One end of the common connecting wires is connected to the TA secondary circuit, and the first conductive connecting piece connects and grounds each common connecting wire;

One end of each main transformer connecting wire of each main transformer connecting wire group is connected with one end of each common connecting wire of said public connecting wire group in a one-to-one correspondence, each main transformer connecting wire of each main transformer connecting wire group The other end of the main transformer is connected to the main transformer protection screen; each main transformer connection line group is connected to one of the main transformer protection screens; each main transformer connection line of each main transformer connection line group is provided with the second conductive Connecting pieces, one main transformer connecting wire in each main transformer connecting wire group is grounded. the

The utility model adopts a switching device, in which multiple sets of main transformer connecting lines are arranged, each group of main transformer connecting lines is connected to a main transformer protection screen, and each main transformer connecting line is provided with a control main transformer connecting line. When it is necessary to run the secondary circuit on behalf of the main transformer, you only need to short-circuit the conductive connecting piece on the main transformer connecting line of the corresponding main transformer protection screen, and connect the conductive connection between the common connecting lines. When there are several main transformers in the same substation, the utility model can share the TA secondary winding, without configuring a TA secondary winding for each main transformer protection screen, and save a lot of secondary cables, which can eliminate the protection dead zone, and reduce costs to improve economic efficiency. the

Description of drawings

Fig. 1 is a prior art TA secondary winding configuration schematic diagram;

Fig. 2 is a switching device structure diagram of a bypass switch of the utility model to operate the TA secondary circuit of the main transformer;

Fig. 3 is a kind of application sketch map of the utility model

Fig. 4 is a configuration schematic diagram of configuring the TA secondary winding by adopting the utility model. the

Detailed ways

In order to facilitate understanding of the utility model, it will be described below in conjunction with the accompanying drawings. the

Please refer to Fig. 2, the utility model discloses a switching device for the bypass switch to operate the TA secondary circuit on behalf of the main transformer, including: public connection line group (including: first public connection line A1A2, second public connection line B1B2, The third common connection line C1C2 and the fourth public connection line D1D2), a plurality of main transformer connection line groups (including: the first main transformer connection line, the second main transformer connection line, the third main transformer connection line and the fourth main transformer connection line Connecting wires; L11, L12, L13 and L14 are one group of main transformer connecting wires; L21, L22, L23 and L24 are another group of main transformer connecting wires; ...... L31, L32, L33 and L34 are another group main transformer connecting wire), the first conductive connecting piece and the second conductive connecting piece;

One end of each public connection line of the public connection line group is connected to the TA secondary circuit, and the first conductive connecting piece connects and grounds each public connecting line. The first conductive connecting piece is arranged on the first common connecting line A1A2, the second common connecting line The connecting line B1B2, the third common connecting line C1C2 and the fourth common connecting line D1D2 are connected and grounded, and when the first conductive connecting pieces (K1, K2, K3 and K4) are closed, each common connecting line can be connected and grounded. grounding;

One end of each main transformer connection line of each main transformer connection line group is connected to one end of each common connection line of the public connection line group in one-to-one correspondence;

Specifically, the first main transformer connection lines L11, L21 and L31 are connected in parallel to the first common connection line A1A2;

The second main transformer connecting lines L12, L22 and L32 are connected in parallel on the second common connecting line B1B2;

The third main transformer connecting lines L13, L23 and L33 are connected in parallel on the third common connecting line C1C2;

The fourth main transformer connection lines L14, L24 and L34 are connected in parallel to the fourth common connection line D1D2;

The other end of each main transformer connection line of each main transformer connection line group is connected to the main transformer protection screen; each main transformer connection line group is connected to a main transformer protection screen;

A second conductive connecting piece is arranged on each main transformer connecting wire of each main transformer connecting wire group, and one main transformer connecting wire in each main transformer connecting wire group is grounded. During specific implementation, any main transformer connecting wire of each main transformer connecting wire group can be grounded, and here, the fourth main transformer connecting wire is grounded. the

The second conductive connecting piece is arranged on the first main transformer connecting wire, the second main transformer connecting wire, the third main transformer connecting wire and the fourth main transformer connecting wire, so as to control the main transformer connecting wires to be energized or de-energized. Each main transformer connecting line is provided with a second conductive connecting piece, specifically, the first main transformer connecting line L11 is provided with a second conductive connecting piece K5, and the second main transformer connecting line L12 is provided with a second conductive connecting piece K6, the third main transformer connection line L13 is provided with a second conductive connection piece K7, the fourth main transformer connection line L14 is provided with a second conductive connection piece K8; the first main transformer connection line L21 is provided with a second conductive connection piece K9, the second conductive connecting piece K10 is set on the second main transformer connecting line L22, the second conductive connecting piece K11 is set on the third main transformer connecting line L23, and the second conductive connecting piece K11 is set on the fourth main transformer connecting line L24. connecting piece K12; the first main transformer connecting line L31 is provided with a second conductive connecting piece K13, the second main transformer connecting line L32 is provided with a second conductive connecting piece K14, and the third main transformer connecting line L33 is provided with a second The conductive connecting piece K15 is provided with a second conductive connecting piece K16 on the fourth main transformer connecting line L34. the

The utility model adopts a switching device, in which multiple sets of main transformer connecting lines are arranged, each group of main transformer connecting lines is connected to a main transformer protection screen, and each main transformer connecting line is provided with a control main transformer connecting line. When it is necessary to run the secondary circuit on behalf of the main transformer, you only need to short-circuit the conductive connecting piece on the main transformer connecting line of the corresponding main transformer protection screen, and connect the conductive connection between the common connecting lines. When there are several main transformers in the same substation, the utility model can share the TA secondary winding, without configuring a TA secondary winding for each main transformer protection screen, and save a lot of secondary cables, which can eliminate the protection dead zone, and reduce costs to improve economic efficiency. the

Among them, the conductive connecting piece is also called a pressure plate, and multiple sets of main transformer connecting wire groups refer to more than two sets of main transformer connecting wire groups. the

The practical application of the utility model is illustrated by taking the substation with 3 main transformers as an example; please refer to Figure 3; the bypass switch replaces the main transformer to run the TA secondary circuit replacement process as follows:

1. When the bypass does not replace any main transformer protection screen, short-circuit the conductive connection piece K1 to the conductive connection piece K4, so that the TA current loop from the bypass unit is short-circuited without on-site open circuit, and there is a reliable grounding point;

2. When bypassing the protective screen 1 of the main transformer, short-circuit the conductive connecting piece K5 to the conductive connecting piece K8 of the TA current loop from the bypass unit, and then disconnect the conductive connecting piece K1 to the conductive connecting piece K4, and rely on Main transformer protection screen 1 is grounded;

3. When bypassing the protective screen 2 of the main transformer, short-circuit the conductive connecting piece K9 to the conductive connecting piece K12 of the TA current loop from the bypass unit, and then disconnect the conductive connecting piece K1 to the conductive connecting piece K4, and rely on 2 places of the main transformer protection screen are grounded;

4. When bypassing the protective screen 3 of the main transformer, short-circuit the conductive connecting piece K13 to the conductive connecting piece K16 of the TA current loop from the bypass unit, and then disconnect the conductive connecting piece K1 to the conductive connecting piece K4, and rely on The main transformer protection screen is grounded at 3 places;

Note: After bypassing the main transformer protection screen 1, main transformer protection screen 2, and main transformer protection screen 3 respectively, the restoration operation sequence is opposite to that of the bypass, for example: for the main transformer protection screen 1, first short the conductive connection Connect sheet K1 to conductive connecting sheet K4, and then disconnect conductive connecting sheet K5 to conductive connecting sheet K8; the operation for other main transformer protection screens is similar. the

Please refer to FIG. 4 , which is a schematic configuration diagram of configuring the TA secondary winding by using the utility model. 1. PM means bypass bus; 1M means first section bus; 2M means second section bus; PDL means bypass switch; DL means main transformer switch; P1G, P2G, P3G means bypass 1M, 2M, PM bus isolation knife ; 1G, 2G, 3G, 4G represent the main transformer 1M, 2M, 3M busbar isolation knife and outlet knife respectively; LH represents the current transformer. Differential protection 2; 3LH P level for busbar protection 1; 4LH P level for busbar protection 2; 5LH P level for failure; 6LH P level for wave recording; 7LH 0.5 level for measurement; 8LH 0.2 level for measurement; on the bypass switch side , 1LH P level for line protection 1, 2LH P level for line protection 2; 3LH P level for variation protection 1; 4LH P level for variation protection 2; 5LH P level busbar protection 1; 6LH P level for busbar protection 2; 7LH 0.5 level to realize failure, wave recording, etc.; 8LH 0.2 level to install instruments; B means main transformer. the

With the improvement of the current transformer (TA) manufacturing process and the protection of the problems existing in the operation of the main transformer generation, now 220KV TA can have 8 secondary windings, and the backup protection no longer needs to use independent secondary windings. In this way, the small difference can be considered to be cancelled, and double sets of large differences are used, and the main transformer switch TA is used for both sets of large differences; similarly, 8 secondary windings can also be used for the bypass switch TA. The utility model is adopted to configure double sets of large differences, and the ILH and 2LH of the main transformer switch DL are used during normal operation; while the bypass switch PDL 3LH and 4LH are used during the substituting operation, which can realize the double set of large differences of the main transformer switch and the bypass switch There is no protection dead zone problem between the bypass switch current transformer (TA) and the high voltage side bushing TA of the main transformer, and the protection dead zone is effectively eliminated. the

The embodiments of the utility model described above do not constitute a limitation to the protection scope of the utility model. Any modifications, equivalent replacements and improvements made within the spirit and principle of the utility model shall be included in the protection scope of the claims of the utility model. the

Claims (1)

1. by-pass switch is characterized in that for the switching device shifter of main transformer operation TA secondary circuit, comprising: bus group, a plurality of main transformer connecting line group, first conductive connecting piece and second conductive connecting piece; One end of each bar bus of said bus group connects the TA secondary circuit, and said first conductive connecting piece is communicated with each bar bus and ground connection;

One end of one end of each main transformer connecting line of each main transformer connecting line group and each bus of said bus group connects one to one, and the other end of each main transformer connecting line of each main transformer connecting line group is connected with said main transformer protection screen; Each main transformer connecting line group connects a said main transformer protection screen;

Each main transformer connecting line of each main transformer connecting line group is provided with said second conductive connecting piece, a main transformer connecting line ground connection in each main transformer connecting line group.

Images