CN103337311B - Oil gas isolated insulation - Google Patents

Abstract

The invention relates to an oil-gas isolation insulator. The oil-gas isolation insulator includes: an insulator plate, multiple oil-side sheds and multiple gas-side sheds, and the multiple oil-side sheds are arranged on the side of the insulator plate that contacts the oil medium. A plurality of gas-side sheds are distributed and arranged on the side of the insulator disk contacting the gas medium, and the plurality of oil-side sheds and the plurality of gas-side sheds are arranged in an asymmetrical cross arrangement with respect to the insulator disk. The oil-gas isolation insulator of the present invention adopts shed structures distributed on both sides of the insulator plate that are in contact with different media, so as to meet the electrical insulation strength requirements of different environments on both sides of the insulator during oil-gas isolation, and the shed structures on both sides adopt cross The form of arrangement can make up for the problem that the concave part of the shed structure of the symmetrical structure is too thin to become a weak point of mechanical load, obtain better mechanical strength, and can withstand the huge pressure when the oil side of the insulator disk is filled with oil medium.

Description

Oil and gas isolation insulator

technical field

The invention relates to an oil-gas isolation insulator.

Background technique

Traditional insulators are generally used in application environments that require insulating support. Insulators play two basic roles in electrical systems, namely supporting conductors and preventing current from returning to ground. These two roles correspond to the mechanical strength requirements of the system and electrical insulation respectively. strength requirements. When insulators are used to isolate different components in power equipment, general equipment such as gas insulated switchgear (GIS for short), etc., the medium on both sides of the pot insulator used is usually the same, so a symmetrical design structure is adopted.

However, in the case of different media on both sides of the insulator, for example, when the two sides are oil and gas, there is a large pressure difference between the oil side and the gas side as the gas pressure changes. On the other hand, when the media on both sides are different, the resistance There are also differences in electric strength, so traditional symmetrical insulators cannot meet the requirements of electrical insulation in different environments on both sides of the insulator during oil-gas isolation, and it is also difficult to meet the mechanical strength requirements of the insulator when the two sides of the insulator are subjected to large different pressures during isolation.

There is also an oil-gas bushing used to connect transformers and GIS, which is too large to limit the range of use, and at the same time, the cost is too high, which is not easy to promote.

Contents of the invention

The purpose of the present invention is to propose an oil-gas isolation insulator, which can meet the electrical insulation requirements and mechanical strength requirements under the operating conditions of a very fast transient overvoltage (VFTO) generator with a steep front.

To achieve the above object, the present invention provides an oil-gas isolation insulator, comprising: an insulator disk, a plurality of oil-side sheds and a plurality of gas-side sheds, and the plurality of oil-side sheds are distributed on the insulator disk The side contacting the oil medium, the plurality of gas-side sheds are distributed and arranged on the side of the insulator plate contacting the gas medium, the plurality of oil-side sheds and the plurality of gas-side sheds are relatively The above-mentioned insulator discs adopt an asymmetric form of cross arrangement.

Further, the oil medium is transformer oil, the gas medium is SF ₆ gas, the length of the oil side shed is greater than the length of the gas side shed, and the angle of the oil side shed is smaller than the gas side shed. The angle of the side skirts.

Further, the insulator disc is a disc-shaped structure.

Further, the middle part of the disk-shaped structure of the insulator disk is provided with a conductor passing hole.

Further, the plurality of oil-side sheds and the plurality of gas-side sheds are distributed symmetrically with respect to the axis of the insulator disc, and the plurality of oil-side sheds and the plurality of gas-side sheds are arranged at equal intervals, and the sheds The pitch and umbrella thickness are the same.

Further, the conductor passing hole is provided with an inner tapered structure on the side of the insulator disk contacting the oil medium, and the inclination angle is the same as that of the oil-side shed.

Further, the insulator disk, multiple oil-side sheds and multiple gas-side sheds are integrally made of high-strength engineering plastics.

Further, the high-strength engineering plastic is cast nylon.

Further, the edge of the insulator disk is provided with a protrusion structure for fixing on the flange, and the contact surface between the protrusion structure and the flange is provided with a rounded structure.

Based on the above technical solution, the oil-gas isolation insulator of the present invention adopts shed structures distributed on both sides of the insulator plate that are in contact with different media respectively, so as to meet the electrical insulation strength requirements of different environments on both sides of the insulator during oil-gas isolation. The shed structure adopts the form of cross arrangement, which can make up for the problem that the thickness of the recess of the shed structure of the symmetrical structure is too thin, which becomes the weak point of mechanical load, obtains better mechanical strength, and can withstand the huge load when the oil side of the insulator plate is filled with oil medium. pressure; in another embodiment, the length of the oil-side shed can be designed to be greater than the length of the air-side shed, and the angle of the oil-side shed can be designed to be smaller than the angle of the air-side shed, so that the oil The side sheds get a longer and less angled shed structure for longer creepage distances.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention and constitute a part of the application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations to the present invention. In the attached picture:

Fig. 1 is a schematic structural view of an embodiment of an oil-gas isolation insulator according to the present invention.

Fig. 2 is a schematic diagram of an installation structure of an embodiment of an oil-gas isolation insulator according to the present invention.

Detailed ways

The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

When separating different parts of the equipment through isolation insulators, the medium on both sides of the pot insulator of general equipment (such as GIS) is usually the same, and when the medium on both sides of the isolation insulator is different, the traditional insulators have different mechanical strength and electrical properties. The insulation requirements cannot meet the requirements of specific environments. When the two sides are oil and gas, there is a large pressure difference between the oil side and the gas side as the gas pressure changes. On the other hand, when the media on both sides are different, the resistance There are also differences in electric strength, which cannot be generalized in terms of insulation design.

In order to adapt to the specific environment of oil-gas isolation, the invention provides a new type of oil-gas isolation insulator, which is especially suitable for application in steep front VFTO (fast transient overvoltage) generators. As shown in FIG. 1 , it is a schematic structural view of an embodiment of the oil-gas isolation insulator of the present invention. In this embodiment, the oil-gas isolation insulator includes an insulator disc 1, a plurality of oil-side sheds 2 and a plurality of gas-side sheds 3, and the plurality of oil-side sheds 2 are distributed and arranged on the side of the insulator disc 1 that contacts the oil medium (that is, the left side in Figure 1), a plurality of gas-side sheds 3 are distributed and arranged on the side of the insulator disk 1 that contacts the gas medium (that is, the right side in Figure 1), and multiple oil-side sheds 2 and A plurality of air-side sheds 3 adopt an asymmetrical cross arrangement with respect to the insulator disk 1 .

In this embodiment, the function of the oil-gas isolation insulator is the same as that of the traditional insulator, both of which play the role of electrical insulation and mechanical fixation, but because the shed structure is arranged on both sides of the insulator disk respectively contacting different media, it can satisfy Electrical insulation strength requirements for different environments on both sides of the insulator during oil-gas isolation.

The shed structure on both sides of the oil-gas isolation insulator in this embodiment adopts the form of cross arrangement, which can make up for the problem that the recess of the shed structure of the traditional insulator symmetrical structure is too thin and becomes a weak point of mechanical load, and obtain better mechanical strength, which can Withstand the huge pressure when the oil side of the insulator plate is filled with oil medium, eliminate the threat that the weak point of the insulator in mechanical strength may bring to the stable operation of the system, and also overcome the large gap between the oil side and the gas side in the oil-gas isolation environment The effect of differential pressure.

In this embodiment, transformer oil can be used as the oil medium, and SF ₆ gas can be used as the gas medium. Among them, the relative dielectric constant of transformer oil is between 2.2 and 2.4, and the relative dielectric constant of SF ₆ gas is 1.002. Considering the flashover distance between the two, the length of the shed on the oil side can be designed to be longer than that on the gas side The length of the shed, the angle of the shed on the oil side is designed to be smaller than the angle of the shed on the gas side, so as to obtain a longer climbing point distance in the transformer.

The use of transformer oil as the transition of the liquid part also takes into account that moisture is the most harmful impurity in SF ₆ gas. If the moisture is not strictly isolated and volatilizes, it will pose a great threat to the safe operation of electrical equipment in the SF ₆ environment. Firstly, the presence of moisture affects the formation of gas decomposition products; secondly, when water and acidic impurities are together, it will corrode the material and cause mechanical operation failure; in addition, moisture will condense on the solid surface at low temperature, causing the flashover voltage along the surface A sharp drop resulted in an accident.

In the material selection of the oil-gas isolation insulator, high-strength engineering plastics can be selected, and the insulator plate, multiple oil-side sheds and multiple gas-side sheds are integrally made during processing. Considering that cast nylon (MC nylon) has the characteristics of light weight, high strength, self-lubricating, wear-resistant, anti-corrosion, insulation, etc., and has relatively stable chemical properties in oil and gas, it is preferred to use high-strength cast nylon for oil-gas isolation insulator.

During processing, the insulator disk 1 can be processed into a disk-shaped structure, and a conductor passing hole 7 can be provided in the middle of the disk-shaped structure of the insulator disk 1 . Based on the disc-shaped insulator disk 1, multiple oil-side sheds 2 and multiple gas-side sheds 3 can be distributed symmetrically with respect to the axis of the insulator disk 1, and multiple oil-side sheds 2 and multiple gas-side The umbrella skirts 3 are arranged at equal intervals, and the umbrella spacing and umbrella thickness are all the same.

The conductor passing hole 7 of the insulator disk 1 is used to pass through the high-voltage conduit (not shown in the figure), and the contact surface of the high-voltage conduit can be sealed with a sealing ring, and the conductor passing hole 7 can be set on the side of the insulator disk that contacts the oil medium. Conical structure, the inclination angle is the same as that of the oil side shed 2. A shield electrode is provided on the high voltage conduit to reduce the possibility of discharge. Through the connection structure of the high-voltage conduit and the conductor passage hole and the shed structure on the oil side, the creepage distance sufficient for the safety threshold of the VFTO generator can be obtained on the oil side. Since the dielectric strength of the gas medium is higher than that of the oil medium, the use of a gas side shed with a smaller length and a larger inclination angle on the gas side can meet the requirements of the dielectric strength of an insulator of the same size, and obtain a sufficient safety threshold for the conductor to the 3MV generator shell .

Referring to Fig. 1, it can be seen that there is still a protruding structure 5 on the edge 4 of the insulator plate, and the protruding structure is used to fix the oil-gas isolation insulator on the flange plate of the VFTO generator and seal it. Refer to Figure 2 for the specific installation structure. The flange 9 fixes the oil-gas isolation insulator by connecting the bolt holes 10 with threads 11 and bolts (not shown in the figure). It can be seen that the flange is connected with the oil-gas isolation insulator and There will be a three-joint point at the junction of the contact surface of transformer oil or SF ₆ gas, which is relatively weak in electrical insulation. The rounded corner structure 6 can be set at this position, and some gaps can be left to be sealed by the sealing ring 8, so as to ensure Sealing reduces the risk of insulation flashover.

In the following, an example of an oil-gas isolation insulator will be given in conjunction with the embodiment in Figure 1. This example has five oil-side sheds on the oil side of the insulator disc, and four gas-side sheds on the gas side. The length of the oil-side sheds is The length of the shed on the air side is 80mm, and the inclination angle is 28.88 degrees. The insulator disk is in the shape of a disc as a whole, with a conductor passage hole in the middle, and the conductor passage hole has an inner tapered structure on the oil side. , the inclination angle is also 20 degrees. The thickness of the insulator plate after removing the oil-side and gas-side sheds is 100 mm, combined with the thickness provided by the sheds on both sides, it can meet the hydraulic and steepening requirements of the VFTO generator (take the Marx generator as an example) after oil filling. Mechanical strength requirements in case the switch part is filled with SF ₆ gas.

A protruding structure with a length of about 25mm and a thickness of 70mm is provided on the edge of the insulator disk, and a rounded corner structure of R5 is provided at the junction of the flange, the insulator, and the contact surface of the transformer oil or SF ₆ gas. When installing the oil-gas isolation insulator, a gap of 3-5mm can be reserved and sealed with a sealing ring.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: the present invention can still be Modifications to the specific implementation of the invention or equivalent replacement of some technical features; without departing from the spirit of the technical solution of the present invention, should be included in the scope of the technical solution claimed in the present invention.

Claims (8)

1. oil gas isolated insulation, it is characterized in that, comprise: insulator disk, multiple oily side full skirt and multiple gas sides full skirt, the full skirt distribution of described multiple oily sides is arranged on the side described insulator disk contacting oily medium, the full skirt distribution of described multiple gas sides is arranged on the side described insulator disk contacting gas medium, described multiple oily side full skirt and described multiple gas sides full skirt adopt the unsymmetric form of arranged crosswise relative to described insulator disk, described multiple oily sides full skirt has longer than described multiple gas sides full skirt, the umbrella skirt construction that angle is less, described oily medium is transformer oil, described gas medium is SF ₆gas.

2. oil gas isolated insulation according to claim 1, it is characterized in that, described insulator disk is disc-shaped structure.

3. oil gas isolated insulation according to claim 2, it is characterized in that, the middle part of the disc-shaped structure of described insulator disk is provided with conductor passing hole.

4. oil gas isolated insulation according to claim 2, it is characterized in that, described multiple oily side full skirt and multiple gas sides full skirt distribute relative to the axisymmetrical of described insulator disk, and described multiple oily side full skirt and multiple gas sides full skirt equidistantly arrange, and umbrella distance is thick all identical with umbrella.

5. oil gas isolated insulation according to claim 3, it is characterized in that, the side that described conductor passing hole contacts oily medium on described insulator disk is provided with inner conical structure, and angle of inclination is identical with the angle of described oily side full skirt.

6. oil gas isolated insulation according to claim 1, it is characterized in that, described insulator disk, multiple oily side full skirt and multiple gas sides full skirt are made into integration by high-strength engineering plastic.

7. oil gas isolated insulation according to claim 6, it is characterized in that, described high-strength engineering plastic is nylon monomer-cast nylon.

8. oil gas isolated insulation according to claim 1, it is characterized in that, the dish edge of described insulator disk is provided with the raised structures for being fixed on ring flange, and the position, contact-making surface boundary of described raised structures and described ring flange is provided with fillet structure.