CN111599556A - Manufacturing method of flexible surface functionally gradient post insulator for extra-high voltage alternating current GIL - Google Patents
Manufacturing method of flexible surface functionally gradient post insulator for extra-high voltage alternating current GIL Download PDFInfo
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- CN111599556A CN111599556A CN202010465493.1A CN202010465493A CN111599556A CN 111599556 A CN111599556 A CN 111599556A CN 202010465493 A CN202010465493 A CN 202010465493A CN 111599556 A CN111599556 A CN 111599556A
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- barium titanate
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B19/00—Apparatus or processes specially adapted for manufacturing insulators or insulating bodies
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C35/00—Heating, cooling or curing, e.g. crosslinking or vulcanising; Apparatus therefor
- B29C35/02—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C39/00—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor
- B29C39/22—Component parts, details or accessories; Auxiliary operations
- B29C39/42—Casting under special conditions, e.g. vacuum
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C71/00—After-treatment of articles without altering their shape; Apparatus therefor
- B29C71/0009—After-treatment of articles without altering their shape; Apparatus therefor using liquids, e.g. solvents, swelling agents
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B19/00—Apparatus or processes specially adapted for manufacturing insulators or insulating bodies
- H01B19/04—Treating the surfaces, e.g. applying coatings
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2063/00—Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2031/00—Other particular articles
- B29L2031/34—Electrical apparatus, e.g. sparking plugs or parts thereof
- B29L2031/3412—Insulators
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- Health & Medical Sciences (AREA)
- Oral & Maxillofacial Surgery (AREA)
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- Application Of Or Painting With Fluid Materials (AREA)
Abstract
The invention discloses a method for manufacturing a flexible surface functionally gradient post insulator for an extra-high voltage alternating current GIL. The method comprises the following steps: 1) preparing an epoxy resin post insulator; 2) preparing electrostatic spraying coating; 3) electrostatic spraying construction process; 4) and (5) curing the coating. According to the invention, the epoxy resin/barium titanate coating is sprayed on the surface of the epoxy resin post insulator by using an electrostatic spraying method, so that the operation is simple and convenient, the efficiency is high, and the coating is uniform; and by controlling the electrostatic spraying position and the concentration of barium titanate in the coating, gradient distribution of dielectric constant is formed on the surface of the epoxy resin, a surface dielectric function gradient material is constructed, the condition of overhigh local electric field under alternating voltage is inhibited, and the electric resistance performance of the insulator is improved.
Description
Technical Field
The invention belongs to preparation of insulation modification of high-voltage equipment, and particularly relates to a manufacturing method of a flexible surface functionally gradient post insulator for an extra-high voltage alternating current GIL.
Background
In order to meet the requirements of large-capacity and long-distance power supply, in recent years, the ultra-high voltage alternating-current transmission technology is gradually favored by the power industry. Gas insulated pipeline power transmission (GIL) is widely used in power transmission technology by virtue of the advantages of large transmission capacity and low loss. The epoxy post insulator is a key component of the insulation support, and the safe and stable operation of a power transmission system is concerned. In the actual operation process of the GIL, the epoxy resin post insulator often has a surface flashover fault, so that the voltage resistance is reduced, and the stable operation of a power system is greatly threatened. The reduction of the insulation performance of the epoxy resin post insulator is related to the uneven distribution of the electric field on the surface of the insulator. The electric field intensity born locally is greater than the whole electric field intensity, even can reach several times of the average electric field intensity, the distortion of the local electric field is serious, and the occurrence of flashover accidents is induced, so that the system has insulation faults.
In order to improve the electric field distribution condition of the post insulator and reduce the occurrence of flashover accidents, the invention provides a method for constructing a flexible surface functional layer by referring to the concept of functional gradient materials in the field of materials science. The flexible surface functional layer is a coating with gradient distribution of dielectric parameters (dielectric constant/conductivity) generated on the surface of the insulator, so that the surface electric field of the insulator is regulated, the electric field distortion is effectively controlled, and the pressure resistance strength of the surface is finally improved. Among the construction methods of the surface functional gradient layer, the electrostatic spraying method has the advantages of simple and convenient operation, high efficiency and uniform coating. The process method is innovatively applied, the epoxy resin/barium titanate mixed coating is sprayed on the surface of the post insulator and is subjected to heating, fixing and forming treatment, an insulating structure with the gradient distribution of dielectric constants is constructed, the alternating current electric field distribution is regulated and controlled through the special electrical parameter characteristics of a target construction material, the electric field uniformity of the surface of the insulator is improved, and the electric resistance performance of the alternating current GIL post insulator is improved.
Disclosure of Invention
The invention aims to provide a manufacturing method of a flexible surface functional gradient post insulator for extra-high voltage alternating current GIL, which comprises the steps of spraying an epoxy resin/barium titanate mixed coating on the surface of the post insulator by an electrostatic spraying process, constructing a flexible functional gradient layer on the surface of the insulator by controlling the electrostatic spraying position and the concentration of barium titanate in the coating, and enhancing the bonding performance of the coating by heating and fixing treatment to regulate and control the electric field distribution condition on the surface of the post insulator under an alternating current electric field, improve the surface flashover voltage of the post insulator in the GIL and improve the electric resistance of the insulator.
The method comprises the following specific processes:
1) preparing an epoxy resin post insulator:
(1) mixing epoxy resin, a curing agent and alumina according to the weight ratio of 100 parts to 35-40 parts to 300-350 parts to obtain an epoxy resin mixed material, then dispersing for 0.5-1h by adopting ultrasonic waves, and uniformly mixing;
(2) vacuum defoaming for 1-2h under the vacuum degree of-0.1 MPa;
(3) pouring the obtained epoxy resin mixed material into a post insulator mold with the inner wall coated with a release agent after preheating treatment (not less than 1h at 130 ℃), carrying out primary curing for 7-8h at 130-140 ℃, and then demolding; then carrying out secondary curing in an oven at 140 ℃ for 7-8h, and cooling to obtain the epoxy resin post insulator;
2) preparing electrostatic spraying coating:
(1) sequentially adding micron barium titanate and a curing agent into epoxy resin under the stirring condition to obtain a mixed solution, and then dispersing for 40-50min by adopting ultrasonic waves, and uniformly mixing; wherein the mass of the curing agent is 25-35% of that of the epoxy resin, and the mass of the micron barium titanate is 10-40% of that of the mixed solution;
(2) placing the mixed solution in a vacuum box, carrying out vacuum defoaming treatment for 40-50min, and removing bubbles in the mixed solution to obtain the electrostatic spraying coating;
3) the electrostatic spraying construction process comprises the following steps:
(1) according to the gradient distribution of the surface of the insulator, the surface is divided into 4 closely connected rings from the center to the outside, and the dielectric constants of the rings are reduced in sequence;
(2) placing the epoxy resin post insulator in electrostatic spraying equipment, wherein a nozzle is aligned with the surface of the insulator;
(3) connecting a power supply of the electrode needle at the position of the spray gun port to electrify the electrode needle;
(4) opening the electrostatic spraying switch to ensure that the coating is directionally sprayed on the surface of the insulator from the nozzle of the spray gun;
(5) controlling the position of a spray gun port and the concentration of barium titanate in the coating, and spraying the coating with different barium titanate concentrations on different positions on the surface of the insulator to form a dielectric constant gradient layer; and the spraying time at different positions is 50 s;
4) curing the coating:
(1) curing the sprayed insulator in an oven at 70-80 ℃ for 4-5h to finish primary curing;
(2) and (3) carrying out secondary curing on the primary cured insulator at the temperature of 130-140 ℃, wherein the curing time is 4-5h, and cooling to obtain the flexible functional gradient basin-type insulator.
In the step 2), the particle size of the micron barium titanate in the step (1) is 10-30 μm.
And in the step 3), the distance between the electrostatic spray gun port and the insulator workpiece in the step 2 is 10 cm.
And in the step 3), the voltage connected with the electrode needle of the electrostatic spray gun in the step 3 is-1 kV.
In the step 3), the concentration of barium titanate in the coating electrostatically sprayed from the center to the outside along the surface of the insulator in the step 5 is 40%, 30%, 20% and 10% in sequence.
And in the step 3), the concentrations of barium titanate in the coating electrostatically sprayed from the center to the outside along the surface of the insulator in the step 5) are 40%, 35%, 30% and 25% in sequence.
And in the step 3), the concentrations of barium titanate in the coating electrostatically sprayed from the center to the outside along the surface of the insulator in the step 5) are 25%, 20%, 15% and 10% in sequence.
The technical scheme of the invention has the following beneficial effects:
according to the invention, the epoxy resin/barium titanate coating is sprayed on the surface of the epoxy resin post insulator by using an electrostatic spraying method, so that the operation is simple and convenient, the efficiency is high, and the coating is uniform; and by controlling the electrostatic spraying position and the concentration of barium titanate in the coating, gradient distribution of dielectric constant is formed on the surface of the epoxy resin, a surface dielectric function gradient material is constructed, the condition of overhigh local electric field under alternating voltage is inhibited, and the electric resistance performance of the insulator is improved. The invention provides an innovative manufacturing process for realizing the surface functional gradient insulator, and has important significance for prolonging the service life of the post insulator in the GIL and improving the operation stability of the GIL and the safety and reliability of a power system.
Drawings
FIG. 1 is a schematic view of an apparatus for electrostatic coating construction of a flexible functionally graded layer;
FIG. 2 is a schematic diagram of the gradient distribution of dielectric constant of the surface of an insulator in a ring pattern;
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
The invention is further illustrated by the following specific examples and the accompanying drawings. The examples are intended to better enable those skilled in the art to better understand the present invention and are not intended to limit the present invention in any way.
The insulator matrix is a post insulator which is cast by bisphenol A epoxy resin, a curing agent and alumina filler. The paint used for electrostatic spraying is epoxy resin/barium titanate mixed paint. Wherein the epoxy resin is bisphenol A epoxy resin of glycidyl ether; the curing agent is polyamide resin HY-651.
Example 1
1) Sequentially adding micron barium titanate and a curing agent into epoxy resin, stirring to obtain a mixed solution, then dispersing for 1h by adopting ultrasonic waves, and uniformly mixing; placing the mixed solution in a vacuum box, carrying out vacuum defoaming treatment for 40min, and removing bubbles in the mixed solution to obtain the electrostatic spraying coating; wherein the mass of the curing agent is 30 percent of that of the epoxy resin, and the mass of the micron barium titanate is 10 to 40 percent of that of the mixed solution;
2) placing the insulator in electrostatic spraying equipment, wherein a nozzle is aligned with the surface of the insulator; connecting a power supply of the electrode needle at the position of the spray gun port to electrify the electrode needle; opening the electrostatic spraying switch to ensure that the coating is directionally sprayed on the surface of the insulator from the nozzle of the spray gun; dividing the surface into 4 connected rings from the center to the outside according to the gradient distribution of the surface of the insulator, and spraying coating materials with different barium titanate concentrations on different positions of the surface of the insulator, wherein the spraying time is 50 s;
3) curing the sprayed insulator in an oven at 80 ℃ for 4h to finish primary curing; and (3) carrying out secondary curing on the insulator subjected to primary curing at the temperature of 130 ℃, wherein the curing time is 4h, and cooling to obtain the flexible functional gradient basin-type insulator.
The concentration of the coating electrostatically sprayed from the center to the outside along the surface of the insulator is 40%, 30%, 20% and 10% in sequence.
Example 2
1) Sequentially adding micron barium titanate and a curing agent into epoxy resin, stirring to obtain a mixed solution, then dispersing for 1h by adopting ultrasonic waves, and uniformly mixing; placing the mixed solution in a vacuum box, carrying out vacuum defoaming treatment for 40min, and removing bubbles in the mixed solution to obtain the electrostatic spraying coating; wherein the mass of the curing agent is 25 percent of that of the epoxy resin, and the mass of the micron barium titanate is 10 to 40 percent of that of the mixed solution;
2) placing the insulator in electrostatic spraying equipment, wherein a nozzle is aligned with the surface of the insulator; connecting a power supply of the electrode needle at the position of the spray gun port to electrify the electrode needle; opening the electrostatic spraying switch to ensure that the coating is directionally sprayed on the surface of the insulator from the nozzle of the spray gun; dividing the surface into 4 connected rings from the center to the outside according to the gradient distribution of the surface of the insulator, and spraying coating materials with different barium titanate concentrations on different positions of the surface of the insulator, wherein the spraying time is 50 s;
3) curing the sprayed insulator in an oven at 70 ℃ for 4h to finish primary curing; and (3) carrying out secondary curing on the primary cured insulator at the temperature of 135 ℃, wherein the curing time is 4h, and cooling to obtain the flexible functional gradient basin-type insulator.
The concentration of the coating electrostatically sprayed from the center to the outside along the surface of the insulator is 40%, 35%, 30% and 25% in sequence.
Example 3
1) Sequentially adding micron barium titanate and a curing agent into epoxy resin, stirring to obtain a mixed solution, then dispersing for 1h by adopting ultrasonic waves, and uniformly mixing; placing the mixed solution in a vacuum box, carrying out vacuum defoaming treatment for 40min, and removing bubbles in the mixed solution to obtain the electrostatic spraying coating; wherein the mass of the curing agent is 35 percent of that of the epoxy resin, and the mass of the micron barium titanate is 10 to 40 percent of that of the mixed solution;
2) placing the insulator in electrostatic spraying equipment, wherein a nozzle is aligned with the surface of the insulator; connecting a power supply of the electrode needle at the position of the spray gun port to electrify the electrode needle; opening the electrostatic spraying switch to ensure that the coating is directionally sprayed on the surface of the insulator from the nozzle of the spray gun; dividing the surface into 4 connected rings from the center to the outside according to the gradient distribution of the surface of the insulator, and spraying coating materials with different barium titanate concentrations on different positions of the surface of the insulator, wherein the spraying time is 50 s;
3) curing the sprayed insulator in an oven at 75 ℃ for 4h to finish primary curing; and (3) carrying out secondary curing on the insulator subjected to primary curing at the temperature of 140 ℃, wherein the curing time is 4h, and cooling to obtain the flexible functional gradient basin-type insulator.
The concentration of the coating electrostatically sprayed from the center to the outside along the surface of the insulator is 25%, 20%, 15% and 10% in sequence.
The description of the present invention is intended to be illustrative, rather than restrictive, and it should be understood by those skilled in the art that various changes may be made without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (7)
1. The manufacturing method of the flexible surface functional gradient post insulator for the extra-high voltage alternating current GIL comprises the following steps:
1) preparing an epoxy resin post insulator:
(1) mixing epoxy resin, a curing agent and alumina according to the weight ratio of 100 parts to 35-40 parts to 300-350 parts to obtain an epoxy resin mixed material, then dispersing for 0.5-1h by adopting ultrasonic waves, and uniformly mixing;
(2) vacuum defoaming for 1-2h under the vacuum degree of-0.1 MPa;
(3) pouring the obtained epoxy resin mixed material into a post insulator mold with the inner wall coated with a release agent after preheating treatment (not less than 1h at 130 ℃), carrying out primary curing for 7-8h at 130-140 ℃, and then demolding; then carrying out secondary curing in an oven at 140 ℃ for 7-8h, and cooling to obtain the epoxy resin post insulator;
2) preparing electrostatic spraying coating:
(1) sequentially adding micron barium titanate and a curing agent into epoxy resin under the stirring condition to obtain a mixed solution, and then dispersing for 40-50min by adopting ultrasonic waves, and uniformly mixing; wherein the mass of the curing agent is 25-35% of that of the epoxy resin, and the mass of the micron barium titanate is 10-40% of that of the mixed solution;
(2) placing the mixed solution in a vacuum box, carrying out vacuum defoaming treatment for 40-50min, and removing bubbles in the mixed solution to obtain the electrostatic spraying coating;
3) the electrostatic spraying construction process comprises the following steps:
(1) according to the gradient distribution of the surface of the insulator, the surface is divided into 4 closely connected rings from the center to the outside, and the dielectric constants of the rings are reduced in sequence;
(2) placing the epoxy resin post insulator in electrostatic spraying equipment, wherein a nozzle is aligned with the surface of the insulator;
(3) connecting a power supply of the electrode needle at the position of the spray gun port to electrify the electrode needle;
(4) opening the electrostatic spraying switch to ensure that the coating is directionally sprayed on the surface of the insulator from the nozzle of the spray gun;
(5) controlling the position of a spray gun port and the concentration of barium titanate in the coating, and spraying the coating with different barium titanate concentrations on different positions on the surface of the insulator to form a dielectric constant gradient layer; and the spraying time at different positions is 50 s;
4) curing the coating:
(1) curing the sprayed insulator in an oven at 70-80 ℃ for 4-5h to finish primary curing;
(2) and (3) carrying out secondary curing on the primary cured insulator at the temperature of 130-140 ℃, wherein the curing time is 4-5h, and cooling to obtain the flexible functional gradient basin-type insulator.
2. The method according to claim 1, wherein the particle size of the micrometer barium titanate in the step (1) in the step 2) is 10 μm.
3. The method according to claim 1, wherein in the step 3), the distance between the electrostatic spray gun mouth and the insulator workpiece in the step (2) is 10 cm.
4. The method according to claim 1, wherein the voltage applied to the electrode needle of the electrostatic spray gun in step (3) in step 3) is-1 kV.
5. The method according to claim 1, wherein the concentration of barium titanate in the coating electrostatically sprayed from the center to the outside along the surface of the insulator in the step (5) in the step 3) is 40%, 30%, 20%, 10% in this order.
6. The method according to claim 1, wherein the concentration of barium titanate in the coating electrostatically sprayed from the center to the outside along the surface of the insulator in the step (5) in the step 3) is 40%, 35%, 30% and 25% in this order.
7. The method according to claim 1, wherein the concentration of barium titanate in the coating electrostatically sprayed from the center to the outside along the surface of the insulator in the step (5) in the step 3) is 25%, 20%, 15%, 10% in this order.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010465493.1A CN111599556A (en) | 2020-07-20 | 2020-07-20 | Manufacturing method of flexible surface functionally gradient post insulator for extra-high voltage alternating current GIL |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202010465493.1A CN111599556A (en) | 2020-07-20 | 2020-07-20 | Manufacturing method of flexible surface functionally gradient post insulator for extra-high voltage alternating current GIL |
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| CN111599556A true CN111599556A (en) | 2020-08-28 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113793739A (en) * | 2021-09-18 | 2021-12-14 | 合肥工业大学 | Preparation method of surface conductivity gradient coating for direct-current GIL epoxy resin insulator |
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2020
- 2020-07-20 CN CN202010465493.1A patent/CN111599556A/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113793739A (en) * | 2021-09-18 | 2021-12-14 | 合肥工业大学 | Preparation method of surface conductivity gradient coating for direct-current GIL epoxy resin insulator |
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Application publication date: 20200828 |