WO2007082455A1

WO2007082455A1 - A ±800kV ULTRAHIGH VOLTAGE DC SYNTHETIC INSULATOR

Info

Publication number: WO2007082455A1
Application number: PCT/CN2006/003621
Authority: WO
Inventors: Jie Zhao; Licheng Li; Hong Yao; Xidong Liang; Bing Luo; Dejin Zhang; Zirong Huang; Congzhen Xie; Tieqiao Liu; Tianren Zhao
Original assignee: China Southern Power Grid Co., Ltd. Power System Technology Research Center; Dongguan Gaoneng Industrial Co., Ltd.
Priority date: 2006-01-17
Filing date: 2006-12-27
Publication date: 2007-07-26
Also published as: CN100412996C; CN1925067A

Abstract

A ±800kV ultrahigh voltage DC synthetic insulator where in a sleeve armor selects the 110-2 methyl vinyl silicon rubber as the base, and is added with a reinforcing agent of vapor phase process carbon-white, a fire retardant of aluminum hydroxide micro power, suitable amount of promoter and vulcanizing agent. After kneaded, the silicon rubber is cured to form the sleeve armor in the mold under the high temperature and the high pressure by an injecting process. The sleeve armor wraps the surface of the core rod. One of the sleeve armors is bigger and the other two are smaller. They are arranged in succession and form a whole insulator with metal mold assembles which is equipped with ball heads and ball nests. The insulator can work at ultrahigh voltage DC transmitting line of ±800kV. The insulator is safe and its pollution flashover property and dirtiness resistance property are good. Its weight is light and size is small. It substantially need not maintenance when it works. The disturbance from corona and wireless is small.

Description

±800kV UHVDC composite insulator Technical Field:

The invention relates to the technical field of insulators, and particularly relates to a ±800kV UHV DC composite insulator. Background technique:

The insulator has porcelain insulator, tempered glass insulator and silicone rubber composite insulator. The porcelain insulator has a long history, and the mechanical and electrical properties meet the requirements of various voltages. Therefore, it has been widely used in AC and DC transmission systems. However, with the increasing air pollution, especially the pollution of the DC system is more serious, the weakness of the porcelain insulators rapidly degraded under the conditions of pollution and humidity is gradually exposed, and the line pollution accident occurs. To this end, people have improved the shape of porcelain insulators, and designed anti-fouling products such as bell-type, double- umbrella, and three-blade. However, the application effects of these products are not ideal, and it is necessary to gradually increase the length of the string during operation. Heavy ice area performance is greatly reduced, and at the same time, a lot of maintenance work such as regular cleaning and zero value detection is required.

Tempered glass insulators have been widely used on various voltage grades. The main advantage is that the mechanical strength is high, the zero-value self-explosion reduces the running workload, the arc resistance is better, and the aging process is slower than the porcelain. It is not enough to affect the cultivation of glass fragments that have a high rate of self-explosion, are vulnerable to external forces, and are scattered.

Silicone rubber composite insulators have a lot of use at home and abroad due to their good flashover performance, light weight, small size, low price, basic maintenance-free operation, small corona, and small electromagnetic interference. Experience, especially in solving the problem of DC pollution, has played an irreplaceable role.

In addition, porcelain insulators or glass insulators are used, the length of the string is too long, and the weight is too heavy, so that the weight of the tower body and the size of the tower head are greatly increased, which increases the construction cost, and at the same time, the excessive length of the insulator string may cause the wind to be excessively large. Problems such as the zero value and the surge in operation and maintenance such as cleaning. The use of synthetic insulators can solve the above problems well. However, from the actual operation of the external insulation of ±500kV and ±600kV ultra-high voltage direct current transmission systems that have been put into operation at home and abroad, it is not ideal, and it is caused by pollution. Insulation accidents are much higher than in the initial design, and some will require a lot of follow-up and other remedial measures soon after they are put into operation.

At present, the ±800kV Yunguang UHV DC transmission project is facing more complicated and harsh external insulation conditions. First, the operating voltage is higher and the maximum operating voltage reaches ±824kV. Secondly, the environment of the line corridor is more complicated. Unfavorable conditions such as bad, high altitude, pollution, ice coating, etc., have placed higher demands on line insulators.

1 Confirmation Summary of the invention:

SUMMARY OF THE INVENTION It is an object of the present invention to provide a ±800 kV UHV DC composite insulator that meets the electrical performance requirements of a ±800 kV DC transmission line for the deficiencies of the prior art.

In order to achieve the above object, the present invention is achieved by the following technical solutions: The shed skirt is made of 110-2 methyl vinyl silicone rubber, and a reinforcing agent fumed silica, flame retardant hydrogen is added. Alumina micropowder, appropriate amount of additives and vulcanizing agent, the formula is as follows:

No. Raw material name Weight ratio

(1) Methyl vinyl silicone rubber 110-2 95-105

(2) Gas phase black carbon black 33. 25~36. 75

(3) Aluminium hydroxide micropowder 118. 75~131. 25

(4) Blue masterbatch 1508# 0. 0665~0. 735

( 5 ) Black masterbatch 1800# 0. 608~0. 672

(6) Zinc dioxide 4. 9~5. 1

(7) A-151 0. 95~1· 05

(8) Hydroxy silicone oil 4. 75~5. 25

(9) Containing H silicone oil 0. 95~1. 05

(10) Methyl silicone oil 201 9. 5~10. 5

(10) Triethanolamine 0. 8455~0. 9345

(12) DCP 1. 0545~1. 1655

5。 The silicone rubber is a combination of several kinds of silicone rubber having a different vinyl content, a molecular weight of 600,000 silicone rubber, a vinyl content of 0.2.

The aluminum hydroxide fine powder has a fineness of 2000 mesh, and the surface of the aluminum hydroxide particles is sprayed with a silicone oil coupling agent. The umbrella structure of the shed skirt is a large two small continuous distribution.

The end of the fitting is formed in the shed sheath, and the connecting end of the cooker is a ball socket or a ball head structure.

The gold fitting is provided with one large and one small equalizing ring, and the pressure equalizing ring has a circular ring structure.

The end of the gold fitting is provided with a sacrificial electrode, and the sacrificial electrode is a pure zinc ring.

The low pressure end equalizing ring is disc shaped.

The umbrella skirt of the invention is selected from the group consisting of 110-2 methyl vinyl silicone rubber, adding reinforcing agent fumed silica, adding flame retardant aluminum hydroxide fine powder, adding appropriate amount of auxiliary agent and vulcanizing agent, The mixture is vulcanized and vulcanized into a shed skirt by a whole injection process in a mold under high temperature and high pressure. According to GB6553- 86 "Test methods for assessing the tracking resistance and electrical corrosion resistance of electrical insulating materials used under severe environmental conditions"; GB / T1602-1992 "Vulcanized rubber insulation" Method for determination of resistivity"; GB I T1693-1992 "Method for determination of loss tangent of vulcanized rubber power frequency dielectric"; DL / T810-2002 "Technical conditions for ±800kV DC rod suspension composite insulator" and other standards including tearing , torsion, DC breakdown strength, water repellency, tracking resistance and other project performance tests, the value of the comprehensive performance of the machine and electricity should meet or exceed the corresponding standard value. The shed skirt of the composite insulator is coated on the surface of the mandrel. The shed skirt is one big and two small and continuously distributed, and is matched with a ball head fitting, a circular ring equalizing ring, and a small ring protection end. The seal is sealed, the large ring reduces the electric field strength at the end, protects the insulator from being aging by the electric field, and also protects the insulator from contamination by dirt, rain, etc., and protects against bird ice and snow; the umbrella skirt is an aerodynamic umbrella design. Self-cleaning ability, able to work in very harsh working conditions, such as ice, high altitude, serious pollution and other harsh environments. The composite insulator of the invention works on ±800kV UHV DC transmission line, is safe and reliable, and has good pollution flashing performance, good pollution resistance, light weight, small size, maintenance-free operation, small corona and small electromagnetic interference. BRIEF DESCRIPTION OF THE DRAWINGS:

1 is a schematic structural view of Embodiment 1 of a ±800 kV UHV DC composite insulator.

2 is a schematic structural view of Embodiment 2 of a ±800 kV UHV DC composite insulator.

Figure 3 is a schematic structural view of an aerodynamic umbrella design.

Referring to Figures 1 and 2, the shed skirt 30 is based on 110-2 methyl vinyl silicone rubber, and is added with a reinforcing agent fumed silica, a flame retardant aluminum hydroxide fine powder, and an appropriate amount. Auxiliary and vulcanizing agent, the preferred formula is as follows: No. Raw material name weight ratio

(1) Methyl methacrylate silicone rubber 110 - 2 100

(2) fumed silica 35

(3) Aluminium hydroxide micropowder 125

(4) Blue masterbatch 1508# 0. 07

(5) Black masterbatch 1800# 0. 64

(6) Zinc dioxide 5

(7) A-151 1

(8) Hydroxy silicone oil 5

(9) H-containing silicone oil 1

(10) Methyl silicone oil 201 10

( 11 ) Triethanolamine 0. 89

( 12) DCP 1. 11 Among them, the silicone rubber is a combination of several kinds of silicone rubbers having different vinyl contents, the molecular weight is 600,000 silicone rubber, and the vinyl content is about 0.20, to improve the mechanical properties and aging properties of the rubber compound.

The surface of the added white carbon black is pretreated, and the silicone oil coupling agent is sprayed on the surface of the white carbon black particles, thereby greatly improving the processing property and water repellency of the silicone rubber shed sheath, and optimizing the addition amount of the white carbon black to the silicone rubber 35 %,

The aluminum hydroxide fine powder is refined, refined to 2000 mesh, and surface pretreated, and a silicone oil coupling agent is sprayed on the surface of the aluminum hydroxide particles, which improves the flame retarding effect due to refinement, and hydrogen is hydrolyzed by surface pretreatment. The surface of the alumina micropowder was changed from hydrophilic to hydrophobic, and the filling amount of the aluminum hydroxide fine powder was optimized to be 125% of the silicone rubber under the condition of both the tracking resistance and the water repellency.

High-performance silicone rubber is produced by advanced mixing-kneading-vacuum mixing process. Various powders are mixed and mixed in batches in an internal mixer, concentrated in a kneading machine, and vacuumed to eliminate low molecular substances. After parking and re-refining, and then adding sulfur after parking, and then providing injection molding to the injection molding machine, the glue produced by this rubber mixing process has good mechanical properties, no sticking, and the product has perfect ^ ^ View

The shed skirt 30 is integrally injection-molded in the injection mold, and the mold is divided into upper and lower halves. The umbrella is processed according to the design, and the eccentric positioning device of the core rod 15 is also installed in the mold to ensure that the eccentricity of the sheath can be controlled. Within the range of 0.5, the upper and lower molds have three points of control temperature, and the mold temperature is controlled within the range of 150±2 degrees. The vulcanization time of each injection is set to 10-14 minutes according to the thickness of the core rod 15 and the thickness of the sheath 30.

Before the production of the composite insulator 1, the core rod 15 is first polished, pre-installed with the metal fitting 2, pre-compression, and the surface of the core rod 15 is coated with the coupling agent AP-133. After the coupling agent is applied, it is pre-charged for 15 minutes. The silicone rubber shed sheath 30 and the seal are injected into the mold, and the injection process is a whole injection process.

The test piece was produced using the above-mentioned rubber compound, and the full-voltage contamination tolerance test was conducted in the STRI high-voltage test room in Sweden. The performance test results showed that the insulator manufactured by using the above-mentioned rubber compound had excellent performance.

The umbrella skirt 30 is designed as an aerodynamic umbrella structure. With the design of the structure, the dust on the umbrella skirt is less, and the dirt on the umbrella is easily removed by the natural wind, and the self-cleaning ability is Strongly, the umbrella structure of the umbrella skirt 30 of the present invention has a large and two small continuous distribution, which can better improve the self-cleaning performance:

If the design of the pitch of the umbrella and the protrusion ratio of the umbrella H/L 1, it is important for the self-cleaning performance of the insulator, and also ensure that the total creepage distance is effective;

Design large and small umbrella stretch A-B 15mm, avoid bridging between large and small umbrellas during rainfall;

The bevel angle of the upper surface of the umbrella plays an important role in its self-cleaning performance, so that it has a bevel angle. The present invention has a tilt angle of 7.5°, which makes it have good self-cleaning performance;

Increase the umbrella pitch and duty ratio (S.-Sw) IS of the umbrella skirt 30. It can also improve its self-cleaning ability, reduce dirt accumulation, and reduce partial discharge on the lower surface of the umbrella skirt. The connecting end of the fitting 2 is designed as a drainage ball socket 10, a ball head rr knot 'construction', a ball socket io, an ir structure to ensure that rainwater flows smoothly along its outer surface, in the fitting 2 There will be no water seams left on it.

In addition, the ends of the fittings 2 and 3 are sealed with high-temperature vulcanized silicone rubber, which greatly improves the reliability of the sealing of the fittings 2 and 3 of the composite insulator 1, and at the same time, because the ends of the fittings 2 and 3 are covered with insulating silicone rubber, The corona 2, 3 ends are free of corona, which greatly prolongs the aging life of the sealed silicone rubber at the ends of the metal fittings 2 and 3.

The metalware 2, 3 end is also provided with a sacrificial electrode 20, and the sacrificial electrode 20 is a pure zinc ring. A large number of operating practices show that under the UHV DC voltage ± 500kV, the silicone rubber composite insulator will occur under the surface leakage current between the end fittings 2, 3 and the sheath 30 sealant, that is, the metal and silica joints will occur. Electrochemical corrosion. The end fittings 2, 3 are at the IE pole, causing the metal material at the joint to be corroded under electrolysis. This electrochemical corrosion is exacerbated when the leakage current increases due to the weakening of the silicone rubber surface due to some factors. This causes the end seal to fail, allowing water vapor to penetrate into the inner cavity of the fitting 2 and etch the core rod 15. In severe cases, the mechanical load-carrying capacity of the insulator 1 is lowered, and even a malignant event such as brittle fracture occurs. The invention adopts the method of metal anode protective layer, that is, the hot-dip galvanizing anti-corrosion technology on the surface of the metal material of the metal fittings 2, 3, no matter where the electrochemical corrosion phenomenon occurs in the metal fittings 2, 3, the corrosion is always the zinc metal plating as the anode. . That is to say, as long as there is a thick enough zinc layer as the protective layer of the main material of the metal fitting, it can ensure that the mechanical bearing capacity of the metal fitting is not affected by the galvanic corrosion during the use period. For the voltage of ±800kV DC, especially between the end fittings 2, 3 and the sheath 30 sealant, it is prone to galvanic corrosion, and the structure of the thick zinc-metal protective layer is targeted, that is, the inlaid pure zinc ring 20 .

The weight of the zinc ring is calculated as follows;

W=I X TX Z

Where W: represents the weight of the metal that is corroded by electricity, in grams;

I: indicates the annual charge amount of galvanic corrosion

Unit: A X h/years (ampere X hours/year)

T : indicates the current duration, unit: number of years

Electrochemical equivalent of Z metal, unit: g/AX h g / ampere X hours.

Calculated value: 1 = 0.5 AX h / years;

T=50years;

Z=1. 2195 g/AX h

The design considers that the galvanic corrosion mainly occurs in the annular contact surface between the end gold fitting zinc layer and the sheath sealant, and the thickness of the zinc layer at this place must be less than half of the thickness of the zinc ring during the 50-year use period. It is equivalent to losing the weight of pure zinc under 50 years of galvanic corrosion.

W = 0.5 X X X X 2195 = 30. 488 g. Therefore, it is determined that the zinc ring has a mass of about 100 g and a purity of not less than 99.8% of pure zinc. This ensures that the end seal is not ineffective due to galvanic corrosion during the 50-year service period, resulting in a mechanical load bearing capacity being affected.

The high-pressure end fittings 3 are provided with one large and one small equalizing rings 26 and 27, and the pressure equalizing rings 26 and 27 have a circular structure. At the high-voltage end of the wire end, a drainage type double equalizing ring design is adopted, the end of the electric field strength is reduced by the large equalizing ring 27, and the end sealing is protected by the small equalizing ring 26, wherein the main function of the equalizing ring 27 is to make The electric field strength of the end of the metal fitting 3 is reduced as much as possible. Therefore, the equalizing ring 27 adopts a closed large ring, and a large diameter aluminum tube is used to form a pressure equalizing ring to increase the radius of curvature thereof, and the surface of the equalizing ring is smooth, and the high voltage end is reduced. Halo interference, increase the pressure equalization effect;

The small equalizing ring 26 is made of a small aluminum tube and is placed close to the sheathed silicone rubber to shield the silicone rubber seal so that the sealed silicone rubber is not accelerated by the electric field.

The UHV DC composite insulator low-voltage end tower end equalizing ring 25 is designed to be closed. The low-pressure end tower end pipe is pressure-sealed and welded into a closed disc by an aluminum plate. It is installed on the top of the DC composite insulator to prevent bird mites. The silicone rubber that bites the top of the insulator also protects against ice and snow.

The synthetic insulator is in the salt density condition of 0.05m/cm2 under the altitude of 1000m, the creepage distance is 35mm/kv, the creepage distance is not less than 30,000mm, and the installation height is 8700mm, which is the first at home and abroad. Second, effectively reduce the height of the tower and reduce the total cost.

Long products are difficult to transport in long distances, and the composite insulator 1 shown in Figure 2 is designed in two sections. The UHV DC composite DC insulator 1 of up to 10 meters is designed as two sections for long-distance transportation, especially in high mountains. It is more convenient to transport and transport in the ridge. The design of the composite insulator 1 is divided into two sections. It has been proved by experiments that it meets the requirements of various electrical parameters of the insulator under the high voltage DC voltage of 800kV, and can work stably for a long time and is basically maintenance-free.

Claims

Claim

1. A ±800kV UHV DC composite insulator, composite insulator (1) including mandrel (15), fittings (2, 3), pressure equalizing rings (25), (26) and (27), shed skirt (30), the shed skirt (30) is coated on the surface of the mandrel (15), the shed skirt (30) is connected to the fittings (2, 3), and the grading ring is respectively mounted on the fittings (2, 3) (25) and (26, 27), characterized in that: the shed skirt (30) is based on 110-2 methyl vinyl silicone rubber, adding a reinforcing agent fumed silica, flame retardant Aluminium hydroxide micropowder, appropriate amount of additives and vulcanizing agent, the formula is as follows:

No. Raw material name Weight ratio

(1) Methyl vinyl silicone rubber 110-2 95~105

(2) Gas phase white carbon black 33. 25~36. 75

(3) Aluminium hydroxide micropowder 118. 75~131. 25

(4) Blue masterbatch 1508# 0. 0665~0. 735

(5) Black masterbatch 1800# 0. 608~0. 672

(6) Zinc dioxide 4. 9~5. 1

(7) A - 151 0. 95~1. 05

(8) Hydroxy silicone oil 4. 75~5. 25

(9) Containing H silicone oil 0. 95~1. 05

(10) Methyl silicone oil 201 9. 5~10. 5

(10) Triethanolamine 0. 8455~0. 9345

(12) DCP 1. 0545~1. 1655

2. The ±800kV UHVDC composite insulator according to claim 1, wherein: said silicone rubber is a combination of several silicone rubbers having different vinyl contents, a molecular weight of 600,000 silicone rubber, and a vinyl content of 0. 2.

The ±800 kV UHVDC composite insulator according to claim 1, wherein the aluminum hydroxide fine powder has a fineness of 2000 mesh, and the surface of the aluminum hydroxide particles is sprayed with a silicone oil coupling agent.

The ±800kV UHVDC composite insulator according to claim 1, characterized in that: the umbrella structure of the shed skirt (30) is a large and two small continuous distribution.

The ±800kV UHVDC composite insulator according to claim 1, wherein: the end of the fitting (2, 3) is formed in the shed sheath (30), and the fitting (2, 3) The connecting end is a ball socket (10) and a ball head (11) structure.

6. The ±800kV UHVDC composite insulator according to claim 1, wherein: said high pressure end fitting (3) is provided with one large and one small equalizing ring (26) and (27), both of which are The pressure rings (26) and (27;) are circular Structure.

7. The ±800kV UHVDC composite insulator according to claim 1, wherein: said metal fittings (2) and (3) are provided with a sacrificial electrode (20) at the end, and the sacrificial electrode (20) is pure zinc. ring.

The ±800kV UHVDC composite insulator according to claim 1, wherein: said composite insulator (1) is formed by connecting two stages in series.

9. The ±800kV UHVDC composite insulator according to claim 1, wherein: the composite insulator is in a salt density condition of 0.05 mg/cm2 in an area below 1000 m, and the creepage distance is 35 mm/kv. The creepage distance is not less than 30,000mm and the installation height is 8700mm.

10. The ±800 kV UHVDC composite insulator according to claim 1, wherein: said low pressure end equalizing ring (25) has a disk shape.