CN118294528B - Analysis method of anti-corona material for generator wire rods, anti-corona material and preparation method - Google Patents
Analysis method of anti-corona material for generator wire rods, anti-corona material and preparation method Download PDFInfo
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Abstract
本发明提供一种发电机线棒防晕材料的分析方法及防晕材料、制备方法，属于防晕材料技术领域，包括获取防晕材料表面的发光图像；将获取到的所述发光图像分解为R、G、B三个颜色通道；提取不同颜色通道的灰度值；将提取到的R、G、B通道的所述灰度值分别进行归一化；从归一化后发光图像灰度值中提取背景光噪声阈值；确定R、G、B至少一个图像中的灰度值高于所述背景光噪声阈值的区域，根据灰度值高于所述背景光噪声阈值的区域的灰度值定量估计电场强度；设置电场强度阈值，当通过R、G、B至少一个图像的灰度值定量估计的电场强度高于所述电场强度阈值时，表示出现电晕放电。本发明具有灵敏检测发电机线棒电晕放电的效果。
The present invention provides an analysis method and an anti-corona material for a generator wire rod, and a preparation method thereof, which belongs to the technical field of anti-corona materials, and includes obtaining a luminous image on the surface of the anti-corona material; decomposing the obtained luminous image into three color channels of R, G, and B; extracting gray values of different color channels; normalizing the extracted gray values of the R, G, and B channels respectively; extracting a background light noise threshold from the gray value of the normalized luminous image; determining an area in which the gray value of at least one image of R, G, and B is higher than the background light noise threshold, and quantitatively estimating the electric field strength according to the gray value of the area in which the gray value is higher than the background light noise threshold; setting an electric field strength threshold, and when the electric field strength quantitatively estimated by the gray value of at least one image of R, G, and B is higher than the electric field strength threshold, it indicates that corona discharge occurs. The present invention has the effect of sensitively detecting corona discharge of a generator wire rod.
Description
Technical Field
The invention relates to the technical field of anti-corona materials, in particular to an analysis method of an anti-corona material of a generator bar, an anti-corona material and a preparation method.
Background
The stator windings of large generators are the main equipment elements for the generation of electrical energy by the generator and are also the main carriers for the flow of current through the generator. In the normal operation process of the power system, the voltage of the end part of the stator bar of the generator is higher, the structure of the end part of the stator winding of the generator is complex, and the phenomenon of uneven electric field distribution is unavoidable, so that corona discharge of the end part of the bar is initiated. The corona discharge of the stator bar of the generator is a common partial discharge phenomenon, and the corona discharge is easy to cause main insulation breakdown under the long-term action, so that the generator is inevitably influenced, and even a machine set is stopped, damaged and the like.
To solve this problem, two measures are adopted in the related art at present: ① Adding an anti-corona layer at the end part of the stator bar, wherein the anti-corona layer is usually made of SiC composite material, and the nonlinear electric conduction characteristic of the anti-corona layer is utilized to uniformly obtain an end electric field so as to inhibit corona discharge; ② Detecting corona discharge by partial discharge detection and ultraviolet imaging, and arranging equipment for maintenance as soon as possible after detecting corona discharge, such as CN
112326544A discloses an electroerosion test method for a stator end material of a generator, however, these methods generally require special detection equipment and complex detection techniques, are susceptible to environmental noise, and threaten the safe operation of the power generation equipment. Therefore, developing a new mode of on-site corona discharge monitoring with lossless, intuitive, etc. features is of great necessity for industrial applications.
Disclosure of Invention
Aiming at the problems, the invention provides an analysis method of the anti-corona material of the generator bar, the anti-corona material and a preparation method thereof, and the surface electric field intensity of the anti-corona material is quantitatively represented, so that the sensitive detection and diagnosis of the corona discharge of the generator bar are realized.
In one aspect, the invention provides a method for analyzing an anti-corona material of a generator bar, comprising the following steps:
acquiring a luminous image of the surface of the anti-corona material;
decomposing the acquired luminous image into an R color channel, a G color channel and a B color channel;
Extracting gray values of an R color channel, a G color channel and a B color channel of the luminous image;
Dividing the gray values of the extracted R color channel, G color channel and B color channel by the respective maximum value for normalization to obtain normalized gray values of the luminous image;
extracting a background light noise threshold value from the normalized luminous image gray level value;
determining areas with gray values higher than the background noise threshold in at least one image of the R color channel, the G color channel and the B color channel, and quantitatively estimating the electric field intensity according to the gray values of the areas with the gray values higher than the background noise threshold;
Setting an electric field intensity threshold, and indicating corona discharge when the electric field intensity quantitatively estimated by the gray value of at least one image of the R color channel, the G color channel and the B color channel is higher than the electric field intensity threshold.
As a further improvement of the present invention, said determining the region in which the gray value of at least one of the R color channel, G color channel, and B color channel is higher than the background noise threshold value, quantitatively estimating the electric field strength from the gray value of the region in which the gray value is higher than the background noise threshold value includes quantitatively estimating the electric field strength using the following estimation equation:
，
Wherein L is the normalized image gray value; a and b are coefficients and E is the electric field strength.
As a further improvement of the invention, said extracting the background noise threshold from the normalized luminescent image gray values comprises calculating an average value of luminescent image non-luminescent area gray values, said background noise threshold being determined based on the average value of non-luminescent area gray values.
As a further improvement of the invention, the background light noise threshold is determined by multiplying the average value of the gray values of the non-light-emitting areas by a set coefficient, wherein the set coefficient ranges from 1.1 to 1.4.
As a further improvement of the present invention, the normalizing the extracted gray values of the R color channel, the G color channel, and the B color channel by dividing the gray values by the respective maximum values respectively includes homogenizing the extracted gray values of the R color channel, the G color channel, and the B color channel by dividing 255.
As a further improvement of the invention, the electric field strength threshold value is set to be in the range of 0.5-1.5kV/mm.
As a further improvement of the present invention, a digital camera is used to acquire the surface luminous image of the antihalation material.
In another aspect, the invention provides an anti-corona material for a generator bar, comprising an epoxy resin polymer matrix and a filler comprising ZnS: cu@SiO 2 electroluminescent particles and carbon black, the anti-corona material having a resistivity of 10 2-1012 Range.
As a further improvement of the invention, the thickness of the SiO 2 shell layer is 50-500nm, the mass fraction of the ZnS: cu@SiO 2 particles is 10% -50%, and the mass fraction of the carbon black is 0% -30%.
In still another aspect, the invention provides a method for preparing an anti-corona material for a generator bar, comprising:
Covering a SiO 2 shell layer on the surface of the ZnS: cu electroluminescent particles by a sol-gel method to obtain ZnS: cu@SiO 2 core-shell structure particles taking SiO 2 as a shell layer;
Blending the ZnS: cu@SiO 2 and carbon black particles with epoxy resin and a curing agent in a set mass fraction to form a mixed coating;
and uniformly coating the mixed coating on a main insulating layer at the end part of the stator bar, and curing at a set temperature to obtain the anti-corona material.
As a further improvement of the invention, when the SiO 2 shell layer is covered on the surface of ZnS: cu electroluminescent particles by adopting the sol-gel method, tetraethoxysilane is used as a precursor, and ammonia water is used as a catalyst.
As a further improvement of the invention, the curing at the set temperature to obtain the anti-corona material comprises curing at 95-105 ℃ for 7.5-8.5 hours under vacuum environment to obtain the anti-corona material.
The invention provides an analysis method of an anti-corona material of a generator bar, the anti-corona material and a preparation method, and has at least one of the following beneficial effects:
1. The luminous characteristics of the electroluminescent particles under a high-voltage electric field are fully utilized, and corona discharge is sensitively detected according to the quantitative corresponding relation between the gray value of the obtained luminous image of the anti-corona material and the electric field intensity;
2. The nonlinear conductivity characteristic of the ZnS: cu and carbon black composite material is utilized to regulate and control the surface resistivity of the main insulation, optimize the electric field distribution and inhibit the generation of corona discharge by adding ZnS: cu@SiO 2 particles and carbon black into the corona prevention material;
3. By constructing SiO 2 shell layers on the surfaces of ZnS-Cu particles, the problem of luminous failure of the ZnS-Cu particles in a high humidity environment can be effectively solved, and the problem that the dielectric breakdown strength is reduced due to the fact that the ZnS-Cu particles are doped in a large amount is avoided.
Drawings
Fig. 1 is a flow chart of an analysis method of an anti-corona material of a generator bar according to an embodiment of the present invention.
Fig. 2 is a schematic cross-sectional view of a generator stator bar coated with an anti-corona material in accordance with an embodiment of the present invention.
Fig. 3 is a luminescence diagram of an anti-corona layer under a rod-plate electrode obtained in an analysis method of an anti-corona material for a generator rod according to an embodiment of the present invention.
Fig. 4 is a luminous diagram of an anti-corona layer under a needle-plate electrode obtained in the analysis method of an anti-corona material of a generator bar according to the first embodiment of the present invention.
Fig. 5 is an R-channel gray scale chart obtained in the analysis method of the anti-corona material of the generator bar according to the first embodiment of the present invention.
Fig. 6 is a surface electric field distribution diagram obtained in an analysis method of an anti-corona material for a generator bar according to an embodiment of the present invention.
Fig. 7 is a graph of a gray value change curve and a field intensity change curve of an R channel along a radial direction in an analysis method of an anti-corona material of a generator bar according to an embodiment of the present invention.
Fig. 8 is a schematic flow chart of a method for preparing an anti-corona material for a generator bar according to a third embodiment of the present invention.
Reference numerals illustrate: 1. a conductor; 2. a main insulation; 3. a middle surface; 4. an antihalation material.
Detailed Description
The following detailed description of the invention is provided in connection with specific embodiments and with accompanying figures 1-8 to enable those skilled in the art to more fully understand the objects, features and effects of the invention.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. To the extent that the definition of a term in this document conflicts with the meaning commonly understood by those skilled in the art to which this invention pertains, the definition set forth in this document controls.
The invention provides an analysis method of an anti-corona material of a generator bar, the anti-corona material and a preparation method thereof, so that sensitive detection of corona discharge of the generator bar is realized.
Example 1
As a specific embodiment of the present invention, this embodiment provides an analysis method for an anti-corona material of a generator bar, referring to fig. 1 and 2, the center of the bar is a conductor 1, a main insulation 2 and an anti-corona material 4 are sequentially coated outside, a middle surface 3 is arranged in the middle of the main insulation 2, an anti-corona layer is formed after the anti-corona material 4 is coated, and ZnS: cu electroluminescent particles are contained in the anti-corona material 4. The analysis method of the corona-preventing material of the generator bar comprises the following specific steps:
s100, acquiring a luminous image of the surface of the anti-corona material;
s200, decomposing the acquired luminous image into R, G, B color channels;
s300, extracting gray values of different color channels of the luminous image;
S400, dividing the extracted gray values of R, G, B channels by the respective maximum values for normalization;
s500, extracting a background light noise threshold value from the normalized luminous image gray value;
S600, determining R, G, B areas with gray values higher than a background light noise threshold value in the image, and quantitatively estimating the electric field strength according to the gray values of the areas with the gray values higher than the background light noise threshold value;
And S700, setting an electric field intensity threshold, and indicating corona discharge when the electric field intensity quantitatively estimated through the gray value of R, G, B images is higher than the electric field intensity threshold.
Specifically, in S100, a light-emitting image of the surface of the antihalation material is captured by a digital camera. Preferably, when the digital camera is used for shooting a luminous image on the surface of the anti-corona material, the sensitivity and the exposure time of the digital camera are reasonably selected, so that the camera can sensitively detect the luminous distribution generated by the anti-corona material, and no obvious overexposure area appears.
Further, in the present example, two different electrode structure samples are given, namely, rod-plate and needle-plate electrode structures, respectively. And shooting the two electrode structure anti-corona materials by using a digital camera to obtain a luminescent image of the luminescent surface of the anti-corona material. Preferably, a digital camera with the model of Canon EOS 80D is adopted for shooting, the camera sensitivity is set to 8000, the aperture is 5.6, and the exposure time is reasonably selected from 0.125 to 0.25 s.
And respectively applying 14 kV alternating current voltage to the test sample to stimulate the test sample to emit light, setting the boosting speed to be 500V/s, and photographing and recording a light-emitting image of the anti-corona material of the test sample by using a digital camera after the voltage is stabilized.
The obtained luminescence of the two electrodes of the rod-plate and the needle-plate is shown in fig. 3 and 4, wherein fig. 3 is a luminescence diagram of the anti-corona layer under the rod-plate electrode, and fig. 4 is a luminescence diagram of the anti-corona layer under the needle-plate electrode.
Fig. 3 and 4 show that the surface of the antihalation material emits blue-green visible light and the brightness of the emitted light gradually decreases as the radius increases (as the distance from the rod electrode or needle electrode increases). The high voltage is applied to the rod electrode and the needle electrode, the intensity of the nearby electric field is highest, so that the strongest luminous brightness is displayed, the electric field intensity gradually decreases along with the increase of the distance from the high-voltage electrode, the gray value in the luminous image also gradually decreases, and the fact that a good corresponding relation exists between the gray value of the luminous image and the electric field intensity shows that the higher the electric field, the higher the luminous brightness of the area is, and the larger the gray value is.
Thus, the electroluminescent properties of the antihalation material are utilized to effectively characterize the electric field strength. Corona discharge is usually initiated under an electric field with an electric field strength of about 30kV/cm, and can be sensitively detected by observing luminescence distribution.
Specifically, in S400, the gray value ranges of the three different color channel images of red (R), green (G), and blue (B) are all 0-255, so the maximum value of the gray values is 255. And dividing the gray value of the extracted R, G, B images by 255 for homogenization to obtain gray maps of R, G, B channel components respectively. As shown in fig. 5, an R-channel component gray scale map is shown. The figure shows that the gray value gradually decreases as the distance from the high voltage electrode increases.
Further, the electric field distribution of the two electrode structures of the rod-plate and the needle-plate is respectively modeled and simulated by a finite element method, so that the correlation between the luminous intensity of the surface of the anti-corona material and the electric field intensity is analyzed. Specifically, the radius of the rod electrode was 3 mm and the radius of the needle electrode was 0.5 mm. The radius of the epoxy resin sheet is 3 cm and the thickness is 1.8 mm; the thickness of the anti-corona coating is 0.5 mm; the radius of the ground electrode was 4 cm a and the thickness was 10 a mm a.
After modeling is completed, R, G, B colors are extracted and analyzed, and the quantitative relation between the luminous brightness and the electric field of the anti-corona material is obtained. Taking a rod-plate electrode luminescence image as an example, R color was extracted from the picture, and the electric field distribution was calculated by the finite element method, and the result is shown in fig. 6. In other embodiments, either the G or B colors may be extracted, or R, G, B colors may be extracted. Comparing the luminous gray value of fig. 5 with the electric field distribution obtained by simulation of fig. 6, it can be known that the surface of the antihalation material has color rings with different radiuses, the color of the color ring is lighter from inside to outside, the color of the color ring near the electrode is darkest, the outermost ring has blue, and the color rings of the two rings have very similar contrast. By comparing with the electric field distribution obtained by simulation in fig. 6, it is determined that the gray value of the luminescent image has a good correspondence with the electric field intensity.
Specifically, in S500, an average value of the non-light-emitting region gradation values of the light-emitting image is calculated, and the background noise threshold is determined based on the average value of the non-light-emitting region gradation values. Preferably, the background noise threshold is determined by multiplying the average value of the gray values of the non-light emitting areas by a set coefficient, wherein the set coefficient ranges from 1.1 to 1.4.
Specifically, in S600, the electric field intensity is estimated according to the gray value of the area with the gray value higher than the background noise threshold, and the electric field intensity is estimated using the following estimation equation:
，
Wherein L is the normalized image gray value; a and b are coefficients, E is the electric field strength in kV/mm.
Specifically, in this embodiment, a is 400, b is 0.5, and the estimation equation is:
。
Fig. 7 is a graph of the gray value change curve and the field intensity change curve of the R channel in the radial direction in the two electrode structures of the rod-plate and the needle-plate, fig. 7 (a) is a rod-plate electrode, fig. 7 (b) is a needle-plate electrode, and the luminous gray value and the electric field intensity of the R channel image in the radial direction are compared, wherein the radius refers to the distance between a certain point of the anti-corona material and the electrode. As can be seen, the gray value initially decreases gradually with increasing radius, and as the radius increases to near a certain threshold, the gray value decreases rapidly to 0, and the antihalation material begins to emit light only when the electric field is above a certain threshold. In addition, in the radius range of 0. m, the gray value curve and the electric field intensity curve can be better fitted, which shows that the luminous image after R component extraction can better represent the electric field. The numerical fitting shows that the luminous gray value and the electric field distribution meet the estimation equation. With the gray values of the image known, the electric field strengths at different locations can be quantitatively estimated using the estimation equation. From the above, when the electric field intensity exceeds the threshold, the antihalation material starts to emit light, and the light emission intensity is correlated with the local electric field magnitude. Therefore, a region of high electric field generated by corona discharge can be easily identified by the light emission distribution of the corona preventing material, thereby realizing detection of corona discharge.
In other embodiments, G or B may be analyzed, or both the R, G, B-channel gray value change and the field strength change may be analyzed.
Specifically, in S700, the electric field intensity threshold is selected within the range of 0.5-1.5kV/mm to enable more severe early warning of corona discharge.
According to the analysis method of the generator bar corona-preventing material, disclosed by the invention, the luminescent characteristics of ZnS: cu particles in the corona-preventing material under a high-voltage electric field are fully utilized, a high-electric field area formed by surface corona discharge can be sensitively identified, and the sensitive detection and diagnosis of the generator bar corona discharge are realized; and through decomposing the luminous image into R, G, B gray images, the electric field intensity can be quantitatively represented by utilizing the gray values according to an estimation equation between the gray values and the electric field intensity, so that the quantitative estimation of the electric field intensity of the anti-corona material is realized, the detection of corona discharge of the generator bar is more accurate, and the problem that the electric field distribution is not easy to acquire is effectively solved.
Example two
As a specific embodiment of the present invention, this embodiment provides a generator bar anti-corona material, and referring to fig. 2, the anti-corona material 4 is used to coat the surface of the main insulation 2 at the end of the bar to suppress corona discharge.
The generator bar anti-corona material provided by the invention comprises an epoxy resin (EP) polymer matrix and a filler, wherein the filler comprises ZnS: cu@SiO 2 electroluminescent particles and carbon black, and the resistivity of the anti-corona material is 10 2-1012 Range.
Specifically, the resistivity of the anti-corona material is regulated and controlled by changing the doping content of ZnS: cu@SiO 2 particles and carbon black, and the increasing of the doping content of ZnS: cu@SiO 2 particles and carbon black can reduce the resistivity of the anti-corona material. The nonlinear electric conductivity of ZnS: cu and carbon black composite material is utilized to optimize electric field distribution and inhibit corona discharge.
The ZnS: cu@SiO 2 electroluminescent particles with the core-shell structure are coated with SiO 2 on the surface of the ZnS: cu, so that on one hand, moisture is prevented from entering the interior of the ZnS: cu particles, and the deterioration of the luminescent performance of the ZnS: cu particles and the influence of salt substances on the insulating performance due to the action of the moisture are avoided; on the other hand, the SiO2 shell layer is a high-energy band gap material, which can block carrier migration and prevent the reduction of insulation breakdown strength when the doping content of ZnS: cu particles is higher.
The ZnS Cu@SiO 2 electroluminescent particles with the core-shell structure are used as a filler, and can generate bright luminescence under the condition of lower electric field intensity, so that the luminescence distribution can be observed conveniently.
The ZnS: cu@SiO 2 particles adopted by the generator bar anti-corona material have semiconductor characteristics, and the resistivity of the composite material can be flexibly regulated and controlled by compounding carbon black filler, so that the effect of uniform stator bar end electric field is achieved, and further the generation of corona discharge is inhibited.
Example III
As a specific embodiment of the present invention, the present embodiment provides a method for preparing an anti-corona material for a generator bar, the anti-corona material including an epoxy resin polymer matrix and a filler containing ZnS: cu@sio 2 electroluminescent particles and carbon black, referring to fig. 8, the method includes the steps of:
S10, covering a SiO 2 shell layer on the surface of ZnS: cu electroluminescent particles by a sol-gel method to obtain ZnS: cu@SiO 2 core-shell structure particles taking SiO 2 as a shell layer;
s20, blending ZnS Cu@SiO 2 and carbon black particles with epoxy resin and a curing agent in a set mass fraction to form a mixed coating;
s30, uniformly coating the mixed coating on a main insulating layer at the end part of the stator bar, and curing at a set temperature to obtain the anti-corona material.
Specifically, in S10, when SiO 2 shell layers are covered on the surfaces of ZnS: cu electroluminescent particles by adopting a sol-gel method, tetraethoxysilane is used as a precursor, and ammonia water is used as a catalyst.
In one example, 5g of ZnS: cu powder was thoroughly mixed in 500mL of ethanol solution, and a certain mass of aqueous ammonia solution was added thereto, and after mixing uniformly, a certain mass of ethyl orthosilicate was slowly dropped into the above mixed solution, and the reaction was stirred at room temperature for 24 hours. Finally drying to obtain the ZnS Cu@SiO 2 particles with the core-shell structure.
Preferably, the SiO 2 shell layer has a thickness of 50-500nm.
Further, the thickness of the SiO 2 shell layer is regulated and controlled by changing the content of ammonia water and tetraethoxysilane and the reaction time.
In S20, the mass fraction of ZnS: cu@SiO 2 particles is 10% -50%, and the mass fraction of carbon black is 0% -30%.
The corona luminous intensity can be enhanced to a certain extent by increasing the content of ZnS: cu@SiO 2, the resistivity of the anti-corona material is reduced, and the resistivity can be reduced by increasing the content of carbon black. And determining proper resistivity according to the using position of the anti-corona material, and further regulating and controlling the doping content of ZnS: cu@SiO 2 and carbon black to meet the requirement of the anti-corona material on the resistivity.
In one example, 0.6g of ZnS: cu@SiO 2 is blended with 2g of epoxy resin, 1.6g of methyltetrahydrophthalic anhydride curative and 0.02g of 2,4, 6-triphenol accelerator, and electrically stirred at 500 rad/min for 30 min to form a hybrid coating.
In one example, 0.6g of ZnS: cu@SiO 2 and 0.05g of carbon black are blended with 2g of epoxy resin, 1.6g of methyltetrahydrophthalic anhydride curative and 0.02g of 2,4, 6-triphenol promoter, and electrically stirred at 500 rad/min for 30min to form a hybrid coating.
In one example, 1.0g of ZnS: cu@SiO 2 and 0.05g of carbon black are blended with 2g of epoxy resin, 1.6g of methyltetrahydrophthalic anhydride curative and 0.02g of 2,4, 6-triphenol promoter, and electrically stirred at 500 rad/min for 30min to form a hybrid coating.
In one example, 1.0g of ZnS: cu@SiO 2 and 0.1g of carbon black are blended with 2g of epoxy resin, 1.6g of methyltetrahydrophthalic anhydride curative and 0.02g of 2,4, 6-triphenol promoter, and electrically stirred at 500 rad/min for 30 min to form a hybrid coating.
In one example, 1.4g of ZnS: cu@SiO 2 and 0.1g of carbon black are blended with 2g of epoxy resin, 1.6g of methyltetrahydrophthalic anhydride curative and 0.02g of 2,4, 6-triphenol promoter, and electrically stirred at 500 rad/min for 30 min to form a hybrid coating.
In one example, 1.4g of ZnS: cu@SiO 2 was blended with 2g of epoxy resin, 1.6g of methyltetrahydrophthalic anhydride curative and 0.02g of 2,4, 6-triphenol accelerator, and electrically stirred at 500 rad/min for 30 min to form a hybrid coating.
Specifically, in S30, the mixed paint is uniformly coated on the main insulation layer at the end of the stator bar, and cured at 100 ℃ for 8 hours to obtain the anti-corona material.
Further, the primary insulation is sanded with sandpaper prior to application of the hybrid paint to enhance primary insulation surface adhesion. Preferably, the primary insulation is an epoxy/quartz composite.
The mixed paint is coated on the surface of the pretreated epoxy/quartz composite material, and the surface is placed in a vacuum box and cured for 8 hours at the temperature of 100 ℃ to obtain the required wire rod corona prevention material, and the wire rod corona discharge of the generator is sensitively detected by utilizing the luminous characteristics of ZnS: cu@SiO 2 particles under a high-voltage electric field.
In another example, the mixed coating is uniformly applied to the main insulation layer at the end of the stator bar and cured at 105 ℃ for 7.5 hours to provide the anti-corona material.
In another example, the mixed coating is uniformly applied to the main insulation layer at the end of the stator bar and cured at 95 ℃ for 8.5 hours to provide the anti-corona material.
According to the doping content difference of ZnS: cu@SiO 2 particles and carbon black, the preparation method of the embodiment can be used for obtaining the anti-corona material with different resistivity.
The preparation method of the generator bar corona-preventing material has the advantages of simple flow, high operation efficiency and convenience for large-scale popularization and use in industry.
According to the invention, epoxy resin is used as a polymer matrix, a core-shell structure ZnS@SiO 2 and carbon black particles are used as fillers, a coating method is used for preparing the generator bar anti-corona material, and a high-voltage electric field region formed by surface corona discharge can be sensitively identified through the electroluminescent property and luminous distribution of the generator bar anti-corona material, so that corona discharge is detected; due to the semiconductive characteristic of the filler, the electric field distribution at the end part of the bar can be uniform, the generation of corona discharge is restrained, and the electric resistance is improved.
The above description is only of the preferred embodiment of the present invention, and is not intended to limit the present invention in any other way, but is intended to cover any modifications or equivalent variations according to the technical spirit of the present invention, which fall within the scope of the present invention as defined by the appended claims.
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| CN114262568A (en) * | 2022-01-20 | 2022-04-01 | 中国石油大学(华东) | Electroluminescent insulation defect self-diagnosis composite coating and preparation method thereof |
| CN116285471A (en) * | 2022-09-15 | 2023-06-23 | 苏州巨峰电气绝缘系统股份有限公司 | Inner anti-corona conductive putty for Roebel transposition bar and application thereof |
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| CN106646159B (en) * | 2016-12-12 | 2019-03-29 | 华北电力科学研究院有限责任公司 | The corona detection method and device of generator stator end winding |
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| CN114262568A (en) * | 2022-01-20 | 2022-04-01 | 中国石油大学(华东) | Electroluminescent insulation defect self-diagnosis composite coating and preparation method thereof |
| CN116285471A (en) * | 2022-09-15 | 2023-06-23 | 苏州巨峰电气绝缘系统股份有限公司 | Inner anti-corona conductive putty for Roebel transposition bar and application thereof |
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