CN209561165U - A kind of explosion-proof casing of ultra-high/extra-high voltage gas-insulated transformer class using isobaric isolation gas chamber - Google Patents

Abstract

The utility model relates to an explosion-proof bushing of an ultra/ultra-high voltage gas-insulated transformer using an isobaric isolation gas chamber, comprising a gas-insulated bushing (1‑1) and a transformer booster seat (1‑2) connected with transformer components The first end of the transformer riser (1‑2) is used to connect with the transformer parts, the first end of the transformer riser (1‑2) is sealed and installed with an insulating isolation support, and the insulation isolation support and the transformer parts can be Transformer outlet oil chamber (1‑5) is formed; the second end of the transformer riser (1‑2) is connected to the gas insulation bushing (1‑1) through a flange, and the transformer riser (1‑2) is connected to the gas insulation bushing The pipe (1-1) is sealed with a conical insulator (1-8) at the joint, and in the inner cavity of the transformer riser (1-2), an isolation is formed between the insulation isolation support and the conical insulator (1-8). The buffer gas chamber (1-3); the isolation buffer gas chamber (1-3) and the bushing main insulating gas chamber (1-6) of the gas insulating bushing (1-1) are all filled with insulating gas. The utility model can improve the safety and reliability of super/ultra-high voltage AC and DC bushings and transformers in operation.

Description

An explosion-proof EHV/UHV gas insulated transformer with equal pressure isolation gas chamber casing

technical field

The utility model belongs to the field of electrical insulation structure design and optimization design of super/ultra-high voltage AC and DC transmission equipment, and in particular relates to an explosion-proof bushing of an ultra/ultra-high voltage gas-insulated transformer using an isobaric isolation gas chamber.

Background technique

Bushing failure is one of the important causes of transformer fires. Although the probability of transformer bushing fires is low, once a fire occurs for some reason, it often causes great damage to the transformer, and even causes damage to adjacent transformers and other electrical equipment. damage, seriously endangering the safe and stable operation of the substation. In the previous cases of transformer fire accidents, the discharge of the bushing tie rod system, the discharge of the porcelain bushing under the bushing, and the discharge of the outlet device in the raised seat are all typical sources of discharge. Once insulation breakdown or flashover occurs in these parts, the high energy generated by the discharge will The arc causes the local oil temperature to rise suddenly, forming oil vapor and cracking flammable gases (hydrogen, methane, ethane, ethylene, acetylene, etc.). The sealing structure of the high seat is broken, and the transformer oil is sprayed from the flange of the bushing or the flange of the raised seat. The combustible gas and oil vapor decomposed after encountering an external aerobic environment will ignite and continue to burn, resulting in the development and expansion of the fire. The fire will spread to Other parts of the transformer. It can be seen that the combined effect of insulation damage and mechanical defects may cause the bushing to explode violently, and the huge energy generated will cause high-risk fires, seriously affecting the safety and reliability of the power system.

Utility model content

The purpose of this utility model is to solve the problems existing in the existing design, and to provide an explosion-proof bushing for super/ultra-high voltage gas-insulated transformers using an isobaric isolation gas chamber. The bushing introduces an isolation buffer gas chamber in the design , when the internal discharge of the bushing leads to damage to the insulating isolation support of the tapered insulator on the bushing side, the insulating isolation support on the transformer side can effectively prevent the transformer oil from flowing into the gas chamber, and at the same time prevent the gas in the bushing from entering the transformer, reducing arc ignition The possibility of transformer oil reduces the probability of bushing and transformer explosion due to internal discharge of the bushing, thereby improving the safety and reliability of EHV/UHV AC and DC bushings and transformers in operation.

In order to achieve the above object, the utility model adopts the following technical solutions to realize:

An explosion-proof bushing for ultra/ultra-high voltage gas-insulated transformers using an equal-pressure isolation gas chamber, including a gas-insulated bushing and a transformer riser connected to transformer components. The first end of the transformer riser is used for connecting with transformer components Connection, the first end of the transformer rising seat is sealed and installed with an insulating isolation support, and a transformer outlet oil chamber can be formed between the insulating isolation support and transformer components; the second end of the transformer rising seat is connected to the gas insulating bushing through a flange, and the transformer A tapered insulator is sealed at the connection between the rising seat and the gas insulating bushing, and an isolation buffer gas chamber is formed between the insulating isolation support and the tapered insulator in the inner cavity of the transformer rising seat; the isolation buffer gas chamber and the gas insulating bushing The main insulating gas chamber of the bushing is filled with insulating gas;

There is a central conductor in the gas-insulated bushing and the transformer riser, and the central conductor is sealed and connected with the tapered insulator and the insulation isolation support; the gas-insulated bushing is equipped with a concentric cylindrical metal shielding electrode;

The ends of the gas insulating bushings are fitted with shielding rings.

The outer insulation of the gas-insulated bushing is a hollow composite/porcelain insulator.

The insulating gas is preferably SF ₆ insulating gas or other environment-friendly insulating gas, such as CO ₂ , N ₂ , PFC gas, CF ₃ I gas, C ₄ F ₇ N gas, and C ₅ F ₁₀ O gas.

The insulation isolation supports are pot insulators, plate insulators, cone insulators or insulation grids, and these insulation isolation supports are insulation isolation supports with insulation, sealing and mechanical support properties.

The concentric cylindrical metal shielding cylindrical electrode includes at least one set of high-voltage electrodes and ground electrodes. The ground electrodes are connected to the ground flange.

The air pressure in the isolation buffer gas chamber is equal to the air pressure in the gas insulating bushing.

The transformer components are transformers, converter transformers or reactors.

Compared with the prior art, the utility model has the following beneficial effects:

The utility model adopts the super/ultra-high voltage gas-insulated transformer explosion-proof bushing of the isobaric isolation gas chamber, which has the following advantages compared with the traditional transformer bushing: the first generation of transformer bushing is usually an oil-immersed paper bushing, Although this type of bushing has been stable in operation for many years, it still has the problems of moisture and leakage; on the other hand, when a discharge occurs inside the bushing, the bushing is prone to explosion and a large-scale fire, which is harmful to the power system. The safe and stable operation of the system poses a great threat. The second-generation bushings are rubber-impregnated paper bushings. The dielectric loss and partial discharge performance of this kind of bushings are comparable to those of oil-impregnated paper bushings. At the same time, they are small in size, light in weight, good in hydrophobicity, strong in stain resistance, and easy to maintain. Advantages; however, this type of casing equipment requires large investment, high manufacturing costs, and high requirements for production conditions and manufacturing processes; in addition, with the continuous increase in transportation capacity, it is difficult to solve the problem of heat generation and heat dissipation of glue-stained paper casing larger. The utility model adopts the super/extreme high voltage gas-insulated transformer explosion-proof bushing with equal pressure isolation gas chamber, and divides the whole bushing into transformer outlet oil chamber, isolation buffer gas chamber and bushing main insulating gas through conical insulator and insulation isolation support. The isolation buffer gas chamber and the main insulating gas chamber of the gas-insulated bushing are filled with insulating gas; firstly, the bushing has the characteristics of light weight; secondly, the design of the bushing introduces an isolation buffer gas chamber , when the internal discharge of the bushing causes damage to the tapered insulator on the bushing side, the insulation isolation support on the transformer side can effectively prevent the transformer oil from flowing into the isolation buffer gas chamber, and at the same time prevent the gas in the bushing from entering the inside of the transformer, reducing arc ignition. Combustion of transformer oil can cause the bushing and transformer to burn and explode, reduce the probability of bushing and transformer explosion due to internal discharge of the bushing, thereby improving the safety and reliability of EHV/UHV AC and DC bushings and transformers in operation Reliability, so the utility model has the characteristics of high casing reliability, low cost, convenient installation and maintenance, no problems such as spontaneous combustion explosion and heat dissipation, and has good development and application prospects.

Description of drawings

Fig. 1 is a schematic cross-sectional view of an explosion-proof bushing for an EHV/UHV gas insulated transformer using an isobaric isolating gas chamber according to an embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view of the structure of an explosion-proof bushing for an EHV/UHV gas insulated transformer using an isobaric isolating gas chamber in another embodiment of the present invention.

Fig. 3 is a schematic structural diagram of the lower part of the embodiment shown in Fig. 1 of the present utility model.

Fig. 4 is a schematic diagram of the structure of the double-layer metal shielding cylindrical electrode used in the explosion-proof bushing of the ultra/ultra-high voltage gas-insulated transformer type using the isobaric isolation gas chamber of the present invention.

In the figure, 1-1-gas insulating bushing, 1-2-transformer riser seat, 1-3-isolating buffer gas chamber, 1-4-shielding ring, 1-5-transformer outlet oil chamber, 1-6-set Tube main insulating air chamber, 1-7-insulation grid, 1-8-cone insulator, 1-9-center conductor, 1-10-concentric cylindrical metal shielding electrode, 1-11-hollow composite/porcelain insulator, 3 -1- high voltage electrode, 3-2- ground electrode, 3-3- insulating rod, 1-12- pot insulator.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is further described.

As shown in Fig. 1 to Fig. 3, the utility model adopts the super/ultra-high voltage gas-insulated transformer type explosion-proof bushing of the isobaric isolation gas chamber, including the gas-insulated bushing 1-1 and the transformer rising seat 1 connected with the transformer parts -2, the transformer riser 1-2 is neck-shaped, the first end of the transformer riser 1-2 (that is, the lower left port shown in the figure) is used to connect with transformer components, the transformer riser 1-2 The first end of the transformer is sealed and installed with an insulating isolation support, and a transformer outlet oil chamber 1-5 can be formed between the insulation isolation support and the transformer components; the second end of the transformer riser 1-2 (that is, the upward end shown in the figure) It is connected to the gas insulating bushing 1-1 through a flange, and the transformer rising seat 1-2 and the gas insulating bushing 1-1 are sealed and installed with a tapered insulator 1-8 at their joint, inside the transformer rising seat 1-2 The isolation buffer gas chamber 1-3 is formed between the insulation isolation support and the tapered insulator 1-8; the isolation buffer gas chamber 1-3 and the casing main insulation gas chamber 1-6 of the gas insulation bushing 1-1 are both Insulating gas is filled; the central conductor 1-9 is arranged in the gas insulating bushing 1-1 and the transformer riser 1-2, and the central conductor 1-9 is sealed and connected with the tapered insulator 1-8 and the insulating isolation support; A concentric cylindrical metal shielding electrode 1-10 is installed inside the gas insulating sleeve 1-1; a shielding ring 1-4 is installed at the end of the gas insulating sleeve 1-1.

As a preferred embodiment of the present invention, the outer insulation of the gas-insulated bushing 1-1 is a hollow composite/porcelain insulator 1-11; the insulating gas is preferably SF ₆ insulating gas, or other environmentally friendly insulating gases, such as CO ₂ , N _2. PFC gas, CF ₃ I gas, C ₄ F ₇ N gas and C ₅ F ₁₀ O gas, etc. Insulation isolation supports are pot insulators, plate insulators, cone insulators or insulating grids. The air pressure in the isolation buffer air chamber 1-3 is equal to the air pressure in the gas insulating sleeve 1-1. Transformer components are transformers, converter transformers or reactors. The ultra/ultra-high voltage gas-insulated transformer type explosion-proof bushing using the isobaric isolation gas chamber described in the utility model is preferably, but not limited to, used for AC transformer inlet and outlet bushings, and converter transformer grid side bushings. The structure, arrangement and quantity of the isolated buffer gas chamber and the insulating isolation supports at both ends of the utility model can be adjusted according to the bushing voltage level and operating conditions, and have a wide range of applications.

With reference to Fig. 4, the concentric cylindrical metal shielding cylindrical electrode 1-10 that the utility model adopts comprises at least one group of high-voltage electrodes 3-1 and grounding electrode 3-2, and grounding electrode 3-2 is connected with grounding flange, and high-voltage electrode 3 The two ends of -1 are respectively connected and fixed to the corresponding ends of the ground electrode 3-2 through a plurality of insulating rods 3-3.

In the explosion-proof bushing of the ultra/ultra-high voltage gas-insulated transformer of the utility model adopting an isobaric isolation gas chamber, two insulating isolation supports are used inside the transformer rising seat 1-2 to form an isolation buffer gas chamber 1-3 and transformer outlet oil Chambers 1-5, bushing main insulating gas chambers 1-6. The insulation isolation support is located between the transformer outlet oil chamber 1-5 and the isolation buffer air chamber 1-3, which plays the role of oil-gas isolation; the conical insulator 1-8 is located between the bushing main insulation air chamber 1-6 and the isolation buffer air chamber Between 1-3, it plays the role of gas-gas isolation. Compared with the prior art, the utility model has the advantages of introducing an isolation buffer gas chamber at the connection between the gas-insulated bushing and the transformer, and when a discharge occurs inside the bushing and the insulation and isolation support on the side of the bushing is damaged, the insulation and isolation support on the transformer side It can prevent gas from entering the inside of the transformer, and at the same time prevent transformer oil from entering the inside of the faulty bushing, effectively reducing the possibility of bushing transformer oil burning, thereby reducing the probability of bushing explosion, and improving the efficiency of EHV/UHV gas-insulated transformer bushings. reliability.

Claims (6)

1. a kind of explosion-proof casing of ultra-high/extra-high voltage gas-insulated transformer class using isobaric isolation gas chamber, which is characterized in that including Gas insulated bushing (1-1) and the power transformer enclosure (1-2) being connected with transformer base part, power transformer enclosure (1-2) First end for being connect with transformer base part, the first end of power transformer enclosure (1-2), which is sealed and installed with, is dielectrically separated from branch Support, is dielectrically separated between support and transformer base part and is capable of forming transformer outlet grease chamber (1-5)；Power transformer enclosure (1- 2) second end and gas insulated bushing (1-1) passes through flanged joint, power transformer enclosure (1-2) and gas insulated bushing (1- 1) it is sealed and installed with tapered insulator (1-8) in junction, in the inner cavity power transformer enclosure (1-2), is dielectrically separated from support and cone Isolation buffer gas chamber (1-3) is formed between type insulator (1-8)；Isolation buffer gas chamber (1-3) and gas insulated bushing (1-1) Casing major insulation gas chamber (1-6) in fill insulating gas；

Be provided with center conductor (1-9) in gas insulated bushing (1-1) and power transformer enclosure (1-2), center conductor (1-9) with Tapered insulator (1-8) and be dielectrically separated from support between be tightly connected；Equipped with concentric inside gas insulated bushing (1-1) Cartridge type metallic shield electrode (1-10)；

The end of gas insulated bushing (1-1) is equipped with shading ring (1-4)；

Air pressure in isolation buffer gas chamber (1-3) is equal to the air pressure in gas insulated bushing (1-1).

2. a kind of ultra-high/extra-high voltage gas-insulated transformer class using isobaric isolation gas chamber according to claim 1 is explosion-proof Casing, which is characterized in that the external insulation of gas insulated bushing (1-1) is hollow combined insulator or hollow porcelain insulator.

3. a kind of ultra-high/extra-high voltage gas-insulated transformer class using isobaric isolation gas chamber according to claim 1 is explosion-proof Casing, which is characterized in that the insulating gas is SF₆Insulating gas, CO₂、N₂, PFC gas, CF₃I gas, C₄F₇N gas or C₅F₁₀O gas.

4. a kind of ultra-high/extra-high voltage gas-insulated transformer class using isobaric isolation gas chamber according to claim 1 is explosion-proof Casing, which is characterized in that being dielectrically separated from support is disc insulator, board-like insulator, tapered insulator or insulated gate.

5. a kind of ultra-high/extra-high voltage gas-insulated transformer class using isobaric isolation gas chamber according to claim 1 is explosion-proof Casing, which is characterized in that concentric cartridge type metallic shield cartridge type electrode (1-10) includes at least one set of high-field electrode (3-1) and ground connection Electrode (3-2), grounding electrode (3-2) and ground connection flanged joint, the both ends of high-field electrode (3-1) respectively with grounding electrode (3-2) Upper corresponding end is connected with each other and is fixed by several insulating bars (3-3).

6. a kind of ultra-high/extra-high voltage gas-insulated transformer class using isobaric isolation gas chamber according to claim 1 is explosion-proof Casing, which is characterized in that the transformer base part is transformer, converter power transformer or reactor.