CN210926855U - Gas-insulated metal-enclosed neutral point complete device - Google Patents

Abstract

The utility model relates to a complete set of gas-insulated metal-enclosed neutral point devices. A gas-insulated metal-enclosed neutral point complete set, wherein both the arrester and the isolating switch are closed structures, and both are arranged vertically; There is a transfer barrel; an intermediate barrel is arranged between the incoming line barrel and the transfer barrel, an intermediate conductor is arranged in the intermediate barrel, and a transfer conductor is arranged in the transfer barrel, and the intermediate conductor is connected with the transfer conductor through the transfer conductor. Connect the arrester under the barrel or the top conductive terminal on the isolating switch; the neutral point connection side of the discharge gap is fixed on the top of the incoming barrel, and the ground side of the discharge gap is conductively connected to the transfer barrel or is provided with a ground connection A branched conductive structure is provided in the wire inlet barrel. The above solution solves the problems that the existing closed neutral point complete equipment needs to set up more air chambers, the structure is more complicated, and the cost is high.

Description

A complete set of gas-insulated metal-enclosed neutral point device

technical field

The utility model relates to a complete set of gas-insulated metal-enclosed neutral point devices.

Background technique

Neutral point complete set is also called transformer neutral point complete set protection device, neutral point gap protection complete set, transformer neutral point gap grounding protection device, gap protection, etc. It is mainly used for neutral point overvoltage of power grid system Protect. The complete set of neutral point device can realize two different operation modes of transformer neutral point grounding operation or ungrounding operation in the power system, so as to avoid the damage to the transformer caused by the increase of the transformer neutral point voltage caused by lightning or system failure.

An existing typical neutral point complete set of devices, such as a transformer neutral point gap grounding protection device disclosed in a Chinese patent with the authorization announcement number CN205389099U and the authorization announcement date of 2016.07.20, includes a base, an isolating switch, a surge arrester and a discharge After connecting the neutral point lead terminal of the transformer and the neutral point of the transformer, it is divided into three circuits, which are the isolation switch, the arrester and the discharge gap. This type of neutral point complete set is an open structure, with a porcelain sleeve as the equipment shell and external insulation. Due to the many exposed parts of the equipment, it is easily affected by climatic and environmental conditions, which is not conducive to the safe and reliable operation of the system.

There are also complete sets of neutral point devices using closed structures in the prior art, such as a complete set of AC neutral point GIS using SF ₆ for insulation disclosed in the Chinese patent application with the application publication number CN108512107A and the application publication date of 2018.09.07. The device, the discharge gap, the isolation switch and the arrester are arranged in the corresponding gas chamber tank, which can avoid pollution, reduce space occupation and increase service life. The Chinese patent with the authorization announcement number CN205029338U and the authorization announcement date of 2016.02.10 also discloses a similar structure.

However, the existing closed neutral point complete equipment needs to set up more air chambers, the structure is more complicated, the cost is high, and there are many sealing points, which affects the reliability of the equipment. At the same time, the existing closed neutral point complete sets of equipment all use the cable inlet end to ground, and the wiring method is relatively simple, which is not suitable for overhead line connection.

Utility model content

The purpose of the utility model is to provide a complete set of gas-insulated metal closed neutral point equipment, which solves the problems that the existing closed neutral point complete equipment needs to set up more air chambers, the structure is more complicated, and the cost is high.

The technical scheme adopted in the present invention is as follows.

A gas-insulated metal-enclosed neutral point complete set, comprising a lightning arrester, an isolating switch and a discharge gap; the discharge gap includes a neutral point connection side and a grounding side, and the neutral point connection side is used for conduction with the neutral point of a transformer , the ground side is used for grounding;

Both the arrester and the isolating switch are closed structures, both are arranged vertically, and the top of the two is provided with a top conductive terminal, and the bottom is provided with a ground terminal;

The top of one of the arrester and the isolating switch is provided with a wire inlet barrel, the top of the other is provided with a transfer barrel, and an intermediate barrel is arranged between the wire inlet barrel and the transfer barrel;

An intermediate conductor is arranged in the intermediate cylinder, and a switching conductor is arranged in the switching cylinder, and the intermediate conductor is connected with the arrester under the switching cylinder or the top conductive terminal on the isolation switch through the switching conductor;

The neutral point connection side of the discharge gap is fixed on the top of the incoming wire barrel, the ground side of the discharge gap is conductively connected to the transfer barrel or is provided with a ground connection end, and the neutral point connection side of the discharge gap and the ground side are exposed to air;

A branched conductive structure is provided in the incoming wire barrel, and the branched conductive structure is simultaneously connected to the arrester under the incoming wire barrel or the top conductive terminal on the isolation switch, the corresponding end of the intermediate conductor and the neutral point connection side of the arrester;

The incoming wire barrel is also provided with incoming wire terminals for conducting with the branch conductive structure, and/or on the neutral point connection side of the discharge gap is provided with incoming wire terminals for conducting with the neutral point of the transformer.

Beneficial effects: By adopting the above scheme, by arranging the wire inlet cylinder, the transfer cylinder and the intermediate cylinder, the structure of the gas-insulated metal closed neutral point complete set can form a closed structure except for the discharge gap, and the intermediate conductor and the transfer can form a closed structure. The conductor can ensure the connection between the arrester and the isolation switch and the neutral point of the transformer, thereby ensuring safety performance and reducing space occupation while meeting the functional requirements. At the same time, the arrester and the isolation switch can be used as the neutral point connection side of the discharge gap Compared with the support base on the grounding side, compared with the prior art, there is no need to set a separate discharge gap support base, and no need to set more cylinders, and the structure is simple, which is beneficial to reduce costs.

As a preferred technical solution, one end of the intermediate cylinder body close to the incoming wire cylinder body is provided with an incoming line side insulating basin, and the incoming wire side insulating basin is used to isolate the intermediate cylinder body from the incoming wire cylinder body.

Beneficial effects: The insulating basin on the incoming line side can realize the isolation of the corresponding compartment, improve the reliability, and facilitate the connection and maintenance of the incoming line.

As a preferred technical solution, the branched conductive structure is formed by a cross joint, one end of the cross joint is fixed on the inlet side insulation basin, and the other three ends are provided with a plug-in conductive structure.

Beneficial effects: the cross joint has a simple structure and is convenient to fix.

As a preferred technical solution, the cross joint is provided with a blind hole extending along the axial direction of the incoming line side insulating pot, and the bottom wall of the blind hole is fixed on the incoming line side insulating pot by screws.

Beneficial effects: the above-mentioned fixing structure can ensure the reliable fixing of the cross joint, and at the same time facilitate the conduction between the cross joint and the intermediate conductor.

As a preferred technical solution, an end of the intermediate cylinder close to the switching cylinder is provided with a switching side insulating basin, and the switching side insulating basin is used to isolate the intermediate cylinder and the switching cylinder.

Beneficial effects: The insulating basin on the transfer side can be arranged to realize the isolation of the corresponding compartment and improve the reliability.

As a preferred technical solution, a switch-side insulating pot is arranged between the transfer cylinder and the isolation switch, and the transfer-side insulating pot is used to isolate the transfer cylinder and the isolation switch.

Beneficial effects: The insulating basin on the switch side can be arranged to realize the isolation of the corresponding compartment and improve the reliability.

As a preferred technical solution, the gas-insulated metal-enclosed neutral point complete set includes a zero-sequence current transformer, and the zero-sequence current transformer is sleeved on the grounding side of the discharge gap.

Beneficial effects: The solution can conveniently realize the fixation of the zero-sequence current transformer and facilitate maintenance.

As a preferred technical solution, the top end of the neutral point connection side of the discharge gap is provided with a neutral point lead terminal, and the neutral point lead terminal is used for conductive connection of the neutral point lead.

Beneficial effects: setting the neutral point lead terminal can meet the wiring requirements of the overhead line and improve the applicability.

As a preferred technical solution, the incoming wire terminal provided on the incoming wire barrel is a plug-in cable terminal.

Beneficial effects: The plug-in cable terminal makes the installation of the equipment completely separate from the cable system, and the cable terminal can be directly pulled out during cable testing and maintenance, which is convenient and efficient.

Description of drawings

1 is a schematic structural diagram of an embodiment of a gas-insulated metal-enclosed neutral point complete set of devices in the present invention;

Fig. 2 is the internal structure schematic diagram of Fig. 1;

Fig. 3 is the circuit schematic diagram of Fig. 2;

4 is a partial enlarged view of the branched conductive structure in FIG. 2;

Fig. 5 is a partial enlarged view of the transfer conductor in Fig. 2;

6 is a schematic diagram of the use state of the gas-insulated metal-enclosed neutral point complete set in FIG. 1 using a cable connection;

FIG. 7 is a schematic diagram of the use state of the gas-insulated metal-enclosed neutral point complete set in FIG. 1 connected by an overhead line.

The names of the components corresponding to the corresponding reference numbers in the figure are: 1-base, 2-surge arrester, 3-isolating switch, 4-line barrel, 51-intermediate barrel, 52-intermediate conductor, 61-transfer Cylinder body, 62-transfer conductor, 70-discharge gap, 71-neutral point connection side, 72-ground side, 8-neutral point lead terminal, 91-line side insulation pot, 92-transfer side insulation pot , 93-switch side insulation basin, 10-cross connector, 11-blind hole, 12-pluggable cable terminal, 13-terminal socket, 14-transformer, 15-cable, 16-overhead line, 17-zero sequence Current Transformer.

Detailed ways

The utility model will be further described below in conjunction with the accompanying drawings.

An embodiment of the gas-insulated metal-enclosed neutral point complete set of the present utility model is shown in Figures 1 and 2, including a base 1, a surge arrester 2, a disconnector 3, an incoming line barrel 4, an intermediate barrel 51, and an adapter barrel body 61 and discharge gap 70 . The arrester 2 and the isolating switch 3 are both closed structures, both of which are arranged vertically, the top of the two is provided with a top conductive terminal, and the bottom is provided with a ground terminal. The incoming wire barrel 4 has a cross-shaped structure and is fixed on the upper end of the arrester 2. The transfer barrel 61 has a three-way structure and is fixed on the upper end of the isolating switch 3. The intermediate barrel 51 is connected to the incoming wire barrel 4 and the transfer barrel. between body 61. As shown in Figures 2 and 3, the arrester 2, the discharge gap 70 and the isolating switch 3 are arranged in parallel, and the isolating switch 3 is used to realize the direct grounding and isolation of the neutral point. It can be opened and closed manually or automatically. 2 and the discharge gap 70 can work normally.

As shown in FIG. 1 and FIG. 2 , the discharge gap 70 is a rod-shaped gap, including a neutral point connection side 71 and a ground side 72 , and both the neutral point connection side 71 and the ground side 72 are exposed to the air. The neutral point connection side 71 includes an insulating pillar and a discharge rod, and the discharge rod is fixed on the top of the insulating pillar. The top end of the insulating support is also provided with a neutral point lead terminal 8, and the neutral point lead terminal 8 is used for the conductive connection of the neutral point lead. The structures of the discharge gap 70 and the neutral point lead terminal 8 are both in the prior art and will not be described in detail here. Of course, in other embodiments, the discharge gap 70 can also be a spherical gap. The gas-insulated metal-enclosed neutral point complete set also includes a zero-sequence current transformer 17, and the zero-sequence current transformer 17 is sleeved on the grounding side 72 of the discharge gap 70 for recording the neutral point zero-sequence The waveform of the current and the discharge current of the discharge gap to facilitate the analysis of the fault.

As shown in FIG. 2 and FIG. 4 , one end of the intermediate cylinder 51 close to the incoming wire cylinder 4 is provided with an incoming line side insulating pot 91 , and the incoming wire side insulating tub 91 is used to isolate the intermediate cylindrical body 51 from the incoming wire cylindrical body 4. A switch-side insulating pot 93 is arranged between the transfer cylinder 61 and the isolation switch, and the transfer-side insulating pot 92 is used to isolate the transfer cylinder 61 from the isolation switch.

The intermediate cylinder 51 is provided with an intermediate conductor 52, and the switching cylinder 61 is provided with a switching conductor 62. The intermediate conductor 52 passes through the switching conductor 62 and is connected to the arrester 2 or the isolation switch 3 under the switching cylinder 61. Top conductive terminal connections. The intermediate conductor 52 has an in-line structure, and the transition conductor 62 has an L-shaped structure. In the direction shown in FIG. 2 , the left end of the intermediate conductor 52 is inserted into the socket of the intermediate conductor 52 provided on the insulation basin 91 on the incoming side, and the right end is inserted into the transfer conductor 62 , and the lower end of the transfer conductor 62 is fixed on the switch side insulation. Basin 93 on.

As shown in FIGS. 2 , 4 and 5 , the incoming wire barrel 4 is provided with a branched conductive structure, and the branched conductive structure is formed by a cross joint 10 . To the extending blind hole 11 , the bottom wall of the blind hole 11 is fixed on the incoming line side insulating pot 91 by screws and conducts with the intermediate conductor socket through the conductive insert on the incoming line side insulating pot 91 . The other three ends of the cross connector 10 are provided with a plug-in conductive structure, and the plug-in conductive structure is a plug-in hole, which is respectively connected with the incoming wire terminal provided on the incoming wire barrel 4 and the arrester 2 below the incoming wire barrel 4 . The top conductive terminal of the arrester 2 is connected to the neutral point connection side 71 of the arrester 2 . A pluggable cable terminal 12 is provided at one end of the incoming wire barrel 4 away from the intermediate barrel 51 for conducting the neutral point cable with a connector, and the other end of the neutral point cable is used for connection with the neutral point of the transformer. The inner end of the plug-in cable terminal 12 is provided with a terminal socket 13, and the terminal socket 13 is connected with the socket on the left end of the cross connector 10 through the terminal connecting conductor, thereby realizing the neutral point of the transformer, the arrester 2, and the discharge gap. 70 and the isolation switch 3 are turned on. Of course, as a conventional technical means in the art, the plug-in conductive structure is connected to the corresponding plug-in connector through the conductive contact fingers.

After the gas-insulated metal-enclosed neutral point complete set is assembled, each of the above-mentioned cylinders is filled with sulfur hexafluoride gas to achieve insulation. The row is led to the main grounding grid, and the grounding side 72 of the discharge gap 70 is led to the grounding of the main grounding grid through the transfer cylinder 61, the cylinder of the isolating switch 3 or the grounding row drawn from the ground connection end. When connecting to the transformer 14, as shown in FIG. 6, the complete set of gas-insulated metal-enclosed neutral points can be connected to the neutral point of the transformer 14 by using the cable 15, or, as shown in FIG. 7, the complete set of gas-insulated metal-enclosed neutral points The device may be connected to the neutral point of the transformer 14 using an overhead line 16 .

During operation, under normal circumstances, the isolating switch 3 is in the off position. When lightning overvoltage and general operation overvoltage invade, the arrester 2 acts, absorbs and releases the overvoltage, and protects the neutral point insulation of the transformer from damage. In this case, the discharge gap 70 will not be broken down. When transient overvoltage such as ferromagnetic resonance and high frequency resonance occurs in the system, the discharge gap 70 breaks down and discharges, the overvoltage is all dropped on the gap, the overvoltage energy is released into the ground, and the neutral point of the transformer is grounded instantaneously to prevent The accident continues and protects the arrester 2 from thermal collapse. According to needs, the isolation switch 3 can be closed manually or automatically to meet the direct grounding requirements.

In the above-mentioned embodiment, the incoming wire barrel 4 is arranged on the top of the arrester 2, and the transfer barrel 61 is arranged on the top of the isolation switch 3. In other embodiments, the incoming wire barrel 4 can also be arranged on the top of the disconnecting switch 3, On the other hand, the adapter cylinder 61 is arranged on the top of the arrester 2 .

In the above-mentioned embodiment, the branched conductive structure is a cross-shaped structure with sockets at three ends. In other embodiments, each connection end of the branched conductive structure can be fixed by screws. 4 is provided with a hand hole for disassembly and assembly, which is a conventional technical means in the field, and will not be described in detail here.

In the above-mentioned embodiment, there are corresponding insulating basins between the cylinders to isolate each other. In other embodiments, the cylinders can also be set as air chambers that communicate with each other, for example, a communicating type insulating basin is used, or, for example, Use an insulating basin equipped with a through valve, and choose to connect two adjacent compartments or isolate two adjacent compartments as required. The structures of the above-mentioned various insulating basins are all in the prior art, and will not be described in detail here. In addition, in other embodiments, a transfer-side insulating pot may also be provided at one end of the intermediate cylinder 51 close to the transfer barrel 61, and the transfer-side insulating pot is used to isolate the intermediate barrel 51 and the transfer barrel 61, At this time, the right end of the middle conductor 52 and the left end of the transfer conductor 62 may both be connected to the conductive insert in the center of the transfer side insulating pot.

In the above-mentioned embodiment, the plug-in cable terminal 12 is provided on the wire inlet barrel 4 as the wire inlet terminal, and the top end of the neutral point connection side 71 of the discharge gap 70 is provided with the neutral point lead terminal 8 . In other embodiments of the present invention, the incoming wire terminal on the incoming wire barrel 4 can also use the neutral point lead terminal 8, and the incoming wire terminal can only be provided at the incoming wire barrel 4, or only in the discharge gap. The neutral point connection side 71 of 70 is provided with an incoming line terminal. When the incoming wire terminal is provided on the neutral point connection side 71 of the discharge gap 70, the incoming wire barrel 4 may be a tee structure, and the branched conductive structure may be a tee joint.

In the above embodiment, the zero-sequence current transformer is sleeved on the grounding side of the discharge gap. In other implementations, the zero-sequence current transformer may also adopt other forms, such as being disposed on the neutral point connection side.

Finally, it should be noted that the above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. , it is still possible to make modifications to the technical solutions described in the foregoing embodiments without creative labor, or to perform equivalent replacements for some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (9)

1. A gas insulated metal enclosed neutral point complete device comprises a lightning arrester, an isolating switch and a discharge gap; the discharge gap comprises a neutral point connecting side and a grounding side, the neutral point connecting side is used for being conducted with a neutral point of the transformer, and the grounding side is used for being grounded;

the method is characterized in that:

the lightning arrester and the isolating switch are both of a closed structure and are vertically arranged, the top parts of the lightning arrester and the isolating switch are provided with top conductive terminals, and the bottom parts of the lightning arrester and the isolating switch are provided with grounding terminals;

the top of one of the lightning arrester and the isolating switch is provided with a wire inlet cylinder, and the top of the other one of the lightning arrester and the isolating switch is provided with a switching cylinder; an intermediate cylinder is arranged between the wire inlet cylinder and the switching cylinder;

a middle conductor is arranged in the middle cylinder, a switching conductor is arranged in the switching cylinder, and the middle conductor is connected with a top conductive terminal on a lightning arrester or an isolating switch below the switching cylinder through the switching conductor;

the neutral point connecting side of the discharge gap is fixed at the top of the wire inlet cylinder, the grounding side of the discharge gap is electrically connected with the adapter cylinder or provided with a grounding connecting end, and the neutral point connecting side and the grounding side of the discharge gap are both exposed in the air;

a branch conductive structure is arranged in the wire inlet cylinder and is simultaneously conducted with a top conductive terminal on the lightning arrester or the isolating switch below the wire inlet cylinder, a corresponding end of the middle conductor and a neutral point connecting side of the lightning arrester;

the wire inlet cylinder is further provided with a wire inlet terminal used for being conducted with the branch conductive structure, and/or a wire inlet terminal used for being conducted with a neutral point of the transformer is arranged on the neutral point connecting side of the discharge gap.

2. The gas insulated metal enclosed neutral point kit of claim 1, wherein: and one end of the middle barrel, which is close to the wire inlet barrel, is provided with a wire inlet side insulation basin, and the wire inlet side insulation basin is used for isolating the middle barrel from the wire inlet barrel.

3. The gas insulated metal enclosed neutral point kit of claim 2, wherein: the branch conducting structure is formed by a cross joint, one end of the cross joint is fixed on the wire inlet side insulating basin, and the other three ends are provided with inserting conducting structures.

4. The gas insulated metal enclosed neutral point kit of claim 3, wherein: the cross joint is provided with a blind hole extending along the axial direction of the wire inlet side insulation basin, and the bottom wall of the blind hole is fixed on the wire inlet side insulation basin through a screw.

5. A gas insulated metal enclosed neutral point kit according to any one of claims 2 to 4, wherein: one end of the middle cylinder body, which is close to the switching cylinder body, is provided with a switching side insulating basin, and the switching side insulating basin is used for isolating the middle cylinder body from the switching cylinder body.

6. A gas insulated metal enclosed neutral point kit according to any one of claims 2 to 4, wherein: and a switch side insulating basin is arranged between the switching cylinder and the isolating switch and used for isolating the switching cylinder from the isolating switch.

7. A gas insulated metal enclosed neutral point kit according to any one of claims 1 to 4, wherein: the gas insulated metal enclosed neutral point complete device comprises a zero sequence current transformer, wherein the zero sequence current transformer is sleeved on the grounding side of the discharge gap.

8. A gas insulated metal enclosed neutral point kit according to any one of claims 1 to 4, wherein: and a neutral point lead terminal is arranged at the top end of the neutral point connecting side of the discharge gap and is used for conducting connection with the neutral point lead.

9. A gas insulated metal enclosed neutral point kit according to any one of claims 1 to 4, wherein: the wire inlet terminal arranged on the wire inlet barrel is a plug-in cable terminal.

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