CN117805561A - Epoxy resin electrical branch degradation observation system and method based on reflected light - Google Patents
Epoxy resin electrical branch degradation observation system and method based on reflected light Download PDFInfo
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- 239000003822 epoxy resin Substances 0.000 title claims abstract description 71
- 229920000647 polyepoxide Polymers 0.000 title claims abstract description 71
- 238000000034 method Methods 0.000 title claims abstract description 57
- 230000015556 catabolic process Effects 0.000 title claims abstract description 55
- 238000006731 degradation reaction Methods 0.000 title claims abstract description 55
- 230000008569 process Effects 0.000 claims abstract description 31
- 238000002474 experimental method Methods 0.000 claims abstract description 25
- 239000004593 Epoxy Substances 0.000 claims description 24
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 21
- 239000000203 mixture Substances 0.000 claims description 16
- 238000012360 testing method Methods 0.000 claims description 13
- 229910052799 carbon Inorganic materials 0.000 claims description 12
- 210000001787 dendrite Anatomy 0.000 claims description 12
- 230000008021 deposition Effects 0.000 claims description 11
- 230000005540 biological transmission Effects 0.000 claims description 10
- 229910002804 graphite Inorganic materials 0.000 claims description 9
- 239000010439 graphite Substances 0.000 claims description 9
- 238000001514 detection method Methods 0.000 claims description 8
- 238000002156 mixing Methods 0.000 claims description 7
- 239000003795 chemical substances by application Substances 0.000 claims description 6
- 239000003921 oil Substances 0.000 claims description 5
- 235000019198 oils Nutrition 0.000 claims description 5
- 230000005611 electricity Effects 0.000 claims description 4
- 230000001678 irradiating effect Effects 0.000 claims description 4
- 229920002545 silicone oil Polymers 0.000 claims description 4
- 238000003756 stirring Methods 0.000 claims description 4
- 238000009849 vacuum degassing Methods 0.000 claims description 4
- 238000001291 vacuum drying Methods 0.000 claims description 4
- 235000015112 vegetable and seed oil Nutrition 0.000 claims description 4
- 239000008158 vegetable oil Substances 0.000 claims description 4
- 230000008901 benefit Effects 0.000 description 7
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- 238000013461 design Methods 0.000 description 1
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- 238000007598 dipping method Methods 0.000 description 1
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Abstract
The invention discloses an epoxy resin electric branch degradation observation system and an observation method based on reflected light, wherein in the observation system, a detected sample comprises an epoxy resin electric branch sample, a high-voltage needle electrode inserted into the epoxy resin electric branch sample and a ground electrode arranged at the bottom of the epoxy resin electric branch sample, an experiment platform is provided with an experiment cavity for accommodating a discharge medium, the voltage provides adjustable voltage, the voltage division is connected with a voltage source through a protection resistor to divide the adjustable voltage, the detected sample flows in from the high-voltage needle electrode through the adjustable voltage and discharges to the ground electrode to generate the electric branch, the reflected light of adjustable wavelength is generated by the irradiation of the reflected light source, a CCD camera faces the detected sample to capture reflected light image data, a partial discharge signal in the discharge process of the detected sample is detected by a partial discharge instrument, and a processor is connected with the CCD camera and the partial discharge instrument to collect the reflected light image data and the partial discharge signal to evaluate the growth characteristic and the partial discharge characteristic of the electric branch.
Description
Technical Field
The invention relates to the technical field of electrical equipment detection, in particular to an epoxy resin electrical branch degradation observation system and an epoxy resin electrical branch degradation observation method based on reflected light.
Background
With further improvement of the transmission voltage level and the transmission capacity of the power system, great challenges are presented to the reliability and stability of the power equipment. The gum dipping paper sleeve is one of main insulating forms of high-voltage power equipment, and plays an insulating role, and also needs to play a certain stress role in operation. The sleeve used in the converter station is a glue-dipped paper sleeve, wherein the epoxy resin insulating material is subjected to the phenomenon of insulation degradation under the combined action of electric stress, thermal stress and mechanical stress in the operation process, and the electric branch is taken as a typical degradation form of the valve side dry sleeve, so that the epoxy resin insulating material is widely paid attention to by students at home and abroad.
Conventional electrical branch tests are typically single transmission light sources, and it is difficult to comprehensively and accurately evaluate the degradation state of an electrical branch. Particularly, it is difficult to combine the change of the partial discharge amount with the change of the electric branch morphology, so that an observation system capable of reflecting the electric branch conduction condition is needed, and a comprehensive detection method and an experimental platform for comprehensively evaluating the degradation state of the epoxy resin valve side dry type bushing insulation degradation sample are needed.
The above information disclosed in the background section is only for enhancement of understanding of the background of the invention and therefore may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.
Disclosure of Invention
In view of the foregoing, it is an object of the present invention to provide an epoxy resin electrical branch degradation observation system and an observation method based on reflected light, which overcome the defects of the prior art. The electrical dendrite state of the epoxy resin sample can be observed through reflected light with different wavelengths, and the partial discharge condition of the electrical dendrite process can be monitored, so that the electrical dendrite state of the epoxy resin sample can be monitored in all directions and in real time.
The aim of the invention is achieved by the following technical scheme.
An epoxy resin electrical branch degradation observation system based on reflected light comprises,
the tested sample comprises an epoxy resin electric branch sample, a high-voltage needle electrode inserted into the epoxy resin electric branch sample and a ground electrode arranged at the bottom of the epoxy resin electric branch sample,
an experiment platform provided with an experiment cavity for accommodating a discharge medium,
a voltage source, which provides an adjustable voltage,
a voltage divider connected with the voltage source through a protection resistor to divide the adjustable voltage, wherein the measured sample flows in from the high-voltage needle electrode through the adjustable voltage and discharges to the ground electrode to generate an electric branch,
a reflection light source for irradiating the sample to be measured to generate reflection light with adjustable wavelength,
a CCD camera facing the sample to be measured to capture the reflected light image data,
a partial discharge instrument for detecting partial discharge signals in the discharge process of the sample to be detected,
and a processor connected to the CCD camera and the partial discharge meter to collect the reflected light image data and the partial discharge signal to evaluate the growth characteristics and the partial discharge characteristics of the electrical tree branches.
The epoxy resin electrical branch degradation observation system based on the reflected light further comprises an oscilloscope used for measuring the adjustable voltage, and the processor is connected with the oscilloscope to correlate the adjustable voltage with the reflected light image data and the local discharge signal.
In the epoxy resin electrical branch degradation observation system based on reflected light, the experiment platform is provided with a transmission light source for irradiating the experiment cavity, and the transmission light source is positioned at one side of the experiment cavity opposite to the CCD camera.
In the epoxy resin electrical branch degradation observation system based on reflected light, the voltage source consists of an alternating current voltage source, a direct current voltage source and a harmonic source.
In the epoxy resin electrical branch degradation observation system based on reflected light, a partial discharge meter measures partial discharge signals in a combined mode of an ultrasonic detection method and a pulse current method, and a processor analyzes partial discharge characteristics based on the partial discharge signals.
In an epoxy resin electric branch degradation observation system based on reflected light, the reflected light source generates reflected light in a visible light wave band, a CCD camera is started to capture reflected light images of electric branches, and a processor distinguishes conductive electric branches and nonconductive electric branches based on the reflected light images; the processor is used for detecting the temperature difference of the internal structure of the conductive electrical branch based on the reflected light image; the reflected light source generates reflected light of ultraviolet light, the CCD camera is started to capture reflected light images of the electric branches, and the processor is used for detecting graphite carbon deposition based on the reflected light images.
In the epoxy resin electrical branch degradation observation system based on reflected light, the reflected light source comprises a ring lamp and a wavelength adjusting device for adjusting the wavelength of the ring lamp.
In the epoxy resin electrical branch degradation observation system based on reflected light, the tested sample is immersed in the discharge medium, and the discharge medium comprises transformer oil, silicone oil or insulating vegetable oil.
In the epoxy resin electric branch degradation observation system based on reflected light, the tested sample comprises epoxy impregnated paper or an epoxy resin electric branch sample.
The observation method of the epoxy resin electrical branch degradation observation system based on reflected light comprises the following steps,
preparing a tested sample, pouring epoxy resin and a curing agent into a three-necked flask according to a mass ratio of 100:85, mixing to form a mixture, placing the mixture into a stirrer, stirring in vacuum, uniformly mixing, and removing air in the mixture;
placing crepe paper in a mould and presetting an electrode, controlling the distance between the tip of a high-voltage needle electrode and a ground electrode to be 2+/-0.2 mm, pouring the mixture into the mould of the preset electrode, and solidifying at constant temperature after vacuum degassing treatment in a vacuum drying oven to obtain a tested sample;
the method comprises the steps that a measured sample is immersed in a discharge medium in an experimental cavity, the measured sample flows in from a high-voltage needle electrode through high-voltage electricity and discharges to a ground electrode to generate electric branches, a reflection light source irradiates the measured sample to generate reflection light with adjustable wavelength, a CCD camera faces the measured sample to capture image data of the reflection light, a partial discharge instrument detects partial discharge signals in the discharge process of the measured sample, and a processor is connected with the CCD camera and the partial discharge instrument to collect the image data of the reflection light and the partial discharge signals so as to evaluate the growth characteristics and the partial discharge characteristics of the electric branches, wherein the reflection light source generates reflection light with a visible light wave band, the CCD camera is started to capture the reflected light image of the electric branches, and the processor is used for distinguishing the conductive electric branches and the nonconductive electric branches based on the reflected light image; the processor is used for detecting the temperature difference of the internal structure of the conductive electrical branch based on the reflected light image; the reflected light source generates reflected light of ultraviolet light, the CCD camera is started to capture reflected light images of the electric branches, and the processor is used for detecting graphite carbon deposition based on the reflected light images.
Compared with the prior art, the invention has the beneficial effects that:
the invention realizes the omnibearing and multidimensional monitoring of the electric tree branch through the synergistic effect of the voltage source, the oscilloscope, the partial discharge instrument and the reflection light sources with different wavelengths, and can provide more comprehensive information of the electric tree branch compared with the traditional method. The reflected light is adopted to observe the electric branch, and the internal structure of the conductive electric branch and the internal structure of the non-conductive electric branch are distinguished through the light irradiation of the adjustable wave band. The method enables the discrimination of the electrical branch property to be more accurate and has higher sensitivity. The multi-band light source observation can be realized, and the system can observe a plurality of wave bands such as visible light, infrared light, ultraviolet light and the like through the adjustable light source wavelength range, so that the characteristics of the electric branch can be more comprehensively known. This provides more information for the in-depth study of the behavior of the electrical tree branches, and the distinction between conductive and non-conductive electrical tree branches is achieved by the adjustable wavelength of reflected light produced by the annular light using the reflected light technique. In the visible band, the conductive branches may appear to be of a particular color, while graphitic carbon deposition may cause it to appear to be darker in color. Infrared light can detect the temperature difference of the internal structure of the conductive electrical branch, and ultraviolet light can trigger fluorescence characteristics, so that the detection of graphite carbon deposition is facilitated. And the CCD camera and the partial discharge detector are combined to realize real-time monitoring of the electric branch. By combining the reflected light information under different wave bands, the system can more comprehensively understand the internal structure and the characteristics of the electric branch, and particularly detect key characteristics such as graphite carbon deposition. This helps to discover potential insulation problems in advance, evaluate the state of development of the electrical tree, and thereby improve the safety and reliability of the device.
The foregoing description is only an overview of the technical solutions of the present invention, to the extent that it can be implemented according to the content of the specification by those skilled in the art, and to make the above-mentioned and other objects, features and advantages of the present invention more obvious, the following description is given by way of example of the present invention.
Drawings
Various other advantages and benefits of the present invention will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. It is evident that the figures described below are only some embodiments of the invention, from which other figures can be obtained without inventive effort for a person skilled in the art. Also, like reference numerals are used to designate like parts throughout the figures.
In the drawings:
FIG. 1 is a schematic diagram of a system for observing the degradation of an epoxy resin electrical branch based on reflected light according to one embodiment of the present invention;
FIG. 2 is a schematic diagram of the structure of a sample under test of a reflected light based epoxy electrical tree degradation observation system according to one embodiment of the present invention;
FIG. 3 is a flow chart of an observation method of an epoxy resin electrical tree degradation observation system based on reflected light according to one embodiment of the present invention;
fig. 4 is a schematic diagram of a reflected light observation flow with different wavelength bands of an epoxy resin electrical tree degradation observation system based on reflected light according to an embodiment of the present invention.
The invention is further explained below with reference to the drawings and examples.
Detailed Description
Specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While specific embodiments of the invention are shown in the drawings, it should be understood that the invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
It should be noted that certain terms are used throughout the description and claims to refer to particular components. Those of skill in the art will understand that a person may refer to the same component by different names. The description and claims do not identify differences in terms of components, but rather differences in terms of the functionality of the components. As used throughout the specification and claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. The description hereinafter sets forth a preferred embodiment for practicing the invention, but is not intended to limit the scope of the invention, as the description proceeds with reference to the general principles of the description. The scope of the invention is defined by the appended claims.
For the purpose of facilitating an understanding of the embodiments of the present invention, reference will now be made to the drawings, by way of example, and specific examples of which are illustrated in the accompanying drawings.
For better understanding, as shown in fig. 1 to 4, an epoxy resin electrical branch degradation observation system based on reflected light includes,
the tested sample comprises an epoxy resin electric branch sample, a high-voltage needle electrode inserted into the epoxy resin electric branch sample and a ground electrode arranged at the bottom of the epoxy resin electric branch sample,
an experiment platform provided with an experiment cavity for accommodating a discharge medium,
a voltage source, which provides an adjustable voltage,
a voltage divider connected with the voltage source through a protection resistor to divide the adjustable voltage, wherein the measured sample flows in from the high-voltage needle electrode through the adjustable voltage and discharges to the ground electrode to generate an electric branch,
a reflection light source for irradiating the sample to be measured to generate reflection light with adjustable wavelength,
a CCD camera facing the sample to be measured to capture the reflected light image data,
a partial discharge instrument for detecting partial discharge signals in the discharge process of the sample to be detected,
and a processor connected to the CCD camera and the partial discharge meter to collect the reflected light image data and the partial discharge signal to evaluate the growth characteristics and the partial discharge characteristics of the electrical tree branches.
In a preferred embodiment of the epoxy electrical tree degradation observation system based on reflected light, further comprising an oscilloscope for measuring the adjustable voltage, the processor is connected to the oscilloscope to correlate the adjustable voltage with said reflected light image data and the partial discharge signal.
In a preferred embodiment of the epoxy resin electrical branch degradation observation system based on reflected light, the experiment platform is provided with a transmission light source for illuminating the experiment cavity, which is located at the side of the experiment cavity opposite to the CCD camera.
In a preferred embodiment of the epoxy electrical tree degradation observation system based on reflected light, the voltage source consists of an ac voltage source, a dc voltage source and a harmonic.
In a preferred embodiment of the epoxy resin electrical branch degradation observation system based on reflected light, the partial discharge meter measures partial discharge signals by adopting a combination method of an ultrasonic detection method and a pulse current method, and the processor analyzes partial discharge characteristics based on the partial discharge signals.
In a preferred embodiment of the epoxy resin electrical tree branch degradation observation system based on reflected light, the reflected light source generates reflected light in a visible light wave band, the CCD camera is started to capture reflected light images of the electrical tree branches, and the processor distinguishes conductive electrical tree branches from non-conductive electrical tree branches based on the reflected light images; the processor is used for detecting the temperature difference of the internal structure of the conductive electrical branch based on the reflected light image; the reflected light source generates reflected light of ultraviolet light, the CCD camera is started to capture reflected light images of the electric branches, and the processor is used for detecting graphite carbon deposition based on the reflected light images.
In a preferred embodiment of the epoxy electrical tree degradation observation system based on reflected light, the reflected light source comprises a ring lamp and a wavelength adjusting device for adjusting the wavelength of the ring lamp.
In a preferred embodiment of the epoxy resin electrical tree degradation observation system based on reflected light, the sample to be measured is immersed in the discharge medium, and the discharge medium comprises transformer oil, silicone oil or insulating vegetable oil.
In a preferred embodiment of the reflected light based epoxy electrical tree degradation observation system, the sample to be tested comprises an epoxy impregnated paper or an epoxy electrical tree specimen.
In one embodiment, the epoxy resin electrical tree branch degradation observation system based on the reflected light can observe the electrical tree branch state through the reflected light with different wavelengths, can monitor the partial discharge condition of the electrical tree branch process, and can monitor the electrical tree branch state of the epoxy resin electrical tree branch sample in an omnibearing and real-time manner. The voltage source consists of an alternating current voltage source, a direct current voltage source and a harmonic wave to simulate the form of electric stress in the real working environment of the sleeve. The reflective light source and the transmissive light source are controlled by independent power sources, so that the electrical branching condition of the sample can be observed by the transmitted light and the reflected light respectively under the condition that the sample is pressurized. The reflection light source adopts annular light, the wavelength of the reflection light source can be adjusted, and the observation of conductive electric branches and non-conductive electric branches under the reflection light of different wave bands is ensured through flexible optical design. The spectrum range of the observation system covers a visible light wave band, an infrared light wave band and an ultraviolet light wave band, so that accurate and comprehensive observation of the electric branch is ensured.
The observation method of the epoxy resin electrical branch degradation observation system based on reflected light comprises the following steps,
preparing a tested sample, pouring epoxy resin and a curing agent into a three-necked flask according to a mass ratio of 100:85, mixing to form a mixture, placing the mixture into a stirrer, stirring in vacuum, uniformly mixing, and removing air in the mixture;
placing crepe paper in a mould and presetting an electrode, controlling the distance between the tip of a high-voltage needle electrode and a ground electrode to be 2+/-0.2 mm, pouring the mixture into the mould of the preset electrode, and solidifying at constant temperature after vacuum degassing treatment in a vacuum drying oven to obtain a tested sample;
the method comprises the steps that a measured sample is immersed in a discharge medium in an experimental cavity, the measured sample flows in from a high-voltage needle electrode through high-voltage electricity and discharges to a ground electrode to generate electric branches, a reflection light source irradiates the measured sample to generate reflection light with adjustable wavelength, a CCD camera faces the measured sample to capture image data of the reflection light, a partial discharge instrument detects partial discharge signals in the discharge process of the measured sample, and a processor is connected with the CCD camera and the partial discharge instrument to collect the image data of the reflection light and the partial discharge signals so as to evaluate the growth characteristics and the partial discharge characteristics of the electric branches, wherein the reflection light source generates reflection light with a visible light wave band, the CCD camera is started to capture the reflected light image of the electric branches, and the processor is used for distinguishing the conductive electric branches and the nonconductive electric branches based on the reflected light image; the processor is used for detecting the temperature difference of the internal structure of the conductive electrical branch based on the reflected light image; the reflected light source generates reflected light of ultraviolet light, the CCD camera is started to capture reflected light images of the electric branches, and the processor is used for detecting graphite carbon deposition based on the reflected light images.
In one embodiment, the method comprises the steps of:
preparing an epoxy resin electric branch sample of a preset high-voltage needle electrode;
constructing a reflected light observation platform, respectively connecting a needle electrode and a plate electrode of a sample with a high-voltage end and a ground electrode, and simultaneously adopting a partial discharge instrument to record an electrical dendronization process;
and (3) observing the electrical dendrite process and the partial discharge characteristic by using reflected light with different wavelengths to jointly analyze the degradation state of the epoxy resin sample.
The step of observing the electrical dendronization of the epoxy resin based on the reflected light comprises the following steps:
polishing a tested sample until the surface is smooth, and firstly, primarily observing the growth process of the electric tree branch by using a transmission light source to ensure that the electric tree branch is initiated;
and (3) observing by adopting reflection lamplight in a visible light wave band, and starting a CCD camera to capture a reflection light image of the electric branch. Recording whether disorder graphite carbon is deposited on the inner wall of the conductive electrical branch, so that reflected light is black, and the color can be reflected under the condition that the inner wall of the non-conductive electrical branch is smooth;
the wavelength of the light, such as infrared light and ultraviolet light, is sequentially adjusted to observe the change of the reflected light. This helps to obtain more detailed information of the internal structure of the electrical tree. And an infrared light source is introduced, and the monitoring of the local discharge hot spot of the electric branch is realized through the thermal infrared imager. This further enriches the monitoring means and provides additional information.
And recording data acquired in the experiment, including reflected light images, partial discharge detection results and the like. And (5) carrying out data analysis and evaluating the growth morphology and characteristics of the electric tree branches.
The method provided by the invention firstly comprises the steps of preparing an epoxy resin electrical branch sample, and ensuring the standardization and consistency of the sample. The degradation state of the specimen is photographed and recorded in real time by a CCD camera to provide a visual reference.
Furthermore, the constant-temperature heating table of the experiment platform has the characteristics of rapidness and stability, and can be used for testing at different temperatures.
The method provided by the invention obtains the image information of the electrical dendrite process of the epoxy resin sample through multiple tests, and establishes a correlation model of the electrical dendrite conductivity type and the discharge characteristic.
The method for observing the degradation of the epoxy resin electrical branch by the variable wavelength reflected light has the characteristics of high efficiency and accuracy, and provides scientific basis for the safe operation of the power system.
The reflected light observation system provided by the invention is suitable for different types of power system equipment and has universality and operability.
In order to ensure the credibility of the experimental results, the experimental platform and the method are subjected to repeated experiments and data verification. The experimental platform has higher stability and reliability, can continuously run for a long time, and is suitable for large-scale test requirements. The CCD camera of the experimental platform has high resolution and high sensitivity, and can shoot clear degradation images under high-speed operation.
As shown in FIG. 2, the test sample comprises a high-voltage needle electrode prefabricated in epoxy resin, high-voltage electricity flows in from the high-voltage needle electrode at the upper part and discharges towards the direction of the ground electrode, and traces generated in the discharging process can leave traces on the test sample, so that the comparison and recording of the subsequent process are facilitated.
Referring to fig. 2, the method includes the steps of:
and step S100, preparing an epoxy impregnated paper or epoxy resin sample of the preset needle electrode.
Preparing a pure epoxy resin electric branch sample of a preset needle electrode by using epoxy resin and a curing agent in a mass ratio of 100:85, and preparing an epoxy impregnated paper cuboid electric branch sample by impregnating crepe paper into a mixed material of the epoxy resin and the curing agent;
step S200, constructing an epoxy resin sample electrical branch degradation observation system based on reflected light
And step S300, the electric branch growth morphology picture obtained by reflected light irradiation and the partial discharge characteristic jointly represent the degradation state of the epoxy resin electric branch sample.
According to some preferred embodiments of the present application, step S100 may include the steps of:
s101, pouring epoxy resin and a curing agent into a clean three-neck flask according to the mass ratio of 100:85;
step S102, placing the mixture into a stirrer with the rotating speed of 150r/min, stirring for 30 minutes in vacuum, uniformly mixing the mixture, and fully removing air in the mixture;
step S103, placing the crepe paper in a designed mould, presetting a needle electrode, controlling the distance between the tip of the high-voltage electrode and the ground electrode to be 2+/-0.2 mm, and pouring the mixture into the mould of the preset electrode
Step S104, placing the fiber into a vacuum drying oven at 70 ℃ for a second round of vacuum degassing treatment for 30min, so as to ensure that the fiber and the epoxy are fully infiltrated;
s105, placing the sample into a constant temperature box at 100 ℃ for curing for 10 hours, and then curing the sample in the constant temperature box at 130 ℃ for 10 hours for secondary curing;
and S106, after the preset time is reached, taking out the sample, cooling to the room temperature, and removing the mold to obtain the epoxy impregnated paper sample.
Further, the step S200 specifically includes:
and step 200, constructing an epoxy resin electrical branch degradation observation platform based on reflected light.
As shown in fig. 1, an epoxy electrical dendronization observation platform based on reflected light is shown.
The discharge medium is contained in the experiment cavity, and the discharge electrode and the test sample work in the cavity in the discharge experiment process.
The recording equipment can observe and record the electrical dendronization process of the sample in the experimental cavity; the electrical dendrite growth process is typically photographed by a CCD camera and then recorded by a processor for characterizing the electrical dendrite state of the epoxy electrical dendrite specimen.
The partial discharge tester can detect partial discharge signals in the discharge process and is used for representing the partial discharge characteristics in the discharge process. In addition, the experiment platform is reliably grounded; the test sample is immersed in the liquid medium, so that the interference of creeping discharge can be avoided; during the test, the test specimen may be immersed in an insulating oil, which may be transformer oil, silicone oil or insulating vegetable oil.
Further, in the step S300, the electric branch growth morphology picture obtained by reflected light irradiation and the partial discharge characteristic jointly characterize the degradation state of the epoxy resin electric branch sample.
The further step S300 specifically includes:
s301: and (3) carrying out preliminary observation on the growth process of the electric tree branch by using a transmission light source so as to ensure the initiation of the electric tree branch.
Polishing a tested sample until the surface is smooth, and observing the electric branch initiation process by using a transmission light source to ensure the electric branch initiation; the voltage was applied starting from an effective value of 1kV and increasing the voltage by 1kV every 5 minutes until a longer than the 10 μm electrical branch was observed in the sample, i.e., the electrical branch was initiated successfully. After the initiation of the electric branch, the electric branch is allowed to continue growing under the voltage required by the experiment.
S302: and (3) observing by adopting reflection lamplight in a visible light wave band, and starting a CCD camera to capture a reflection light image of the electric branch.
A reflected light image of the electrical tree branch is captured. It is well recorded whether disorder graphitic carbon deposition occurs on the inner walls of the conductive electrical branches, resulting in the reflected light appearing black. Meanwhile, the condition that the inner wall of the non-conductive electrical branch is smooth is observed, and the reflected light can reflect out light. It was recorded whether there was random graphitic carbon deposition on the inner walls of the conductive branches, resulting in the reflected light appearing black.
S303: the change of reflected light is observed by sequentially adjusting the wavelength of the lamplight, and the monitoring of the local discharge hot spot of the electric branch can be realized through the thermal infrared imager.
The wavelength of the light, such as infrared light and ultraviolet light, is sequentially adjusted to observe the change of the reflected light. Helping to obtain more detailed information of the internal structure of the electric branch. And the infrared light source is adopted for irradiation, and the monitoring of the partial discharge hot spot of the electric branch is realized through the thermal infrared imager. And (3) observing the growth condition of the electric branch in the pressurizing process in real time by adopting an infrared thermal imager, and monitoring the temperature distribution in the electric branch. The image obtained by the thermal infrared imager can show the temperature distribution condition in the electric branch, in particular to the local heating caused by the local discharge.
S304: experimental data were recorded and the growth morphology and characteristics of the electrical branches were assessed.
And recording data acquired in the experiment, including reflected light images, partial discharge detection results and the like. Data analysis was performed to assess the growth morphology of the electrical tree branches. Further, the growth characteristics and partial discharge characteristics of the electrical tree under the irradiation of reflected light are recorded, and the reflection conditions observed under the irradiation of the reflected light of different wave bands of the electrical tree are related to the discharge quantity and the discharge phase.
According to the invention, through the recording equipment, the discharge process of the epoxy resin electrical branch sample in the experimental cavity can be observed and recorded; shooting an electrical dendrite process by a CCD camera to represent the growth characteristics of the electrical dendrite in the discharge process; the partial discharge signal in the discharge process can be detected through the partial discharge tester and is used for representing the partial discharge characteristic in the discharge process, so that the degradation state of the epoxy resin sample is represented through the combination of the growth characteristic of the electric branch and the partial discharge characteristic, and the conductivity and the partial discharge amount in the growth process of the electric branch are related to the phase. The experimental platform provided by the invention irradiates reflected light of different wavebands in the electrical dendronization process of the epoxy resin sample, obtains the electrical dendronization condition of the epoxy resin sample, is related to the partial discharge quantity and the partial discharge phase, and provides a brand-new method for researching the electrical dendronization condition of the epoxy resin sample and analyzing the insulation failure mechanism.
The basic principles of the present application have been described above in connection with specific embodiments, however, it should be noted that the advantages, benefits, effects, etc. mentioned in the present application are merely examples and not limiting, and these advantages, benefits, effects, etc. are not to be considered as necessarily possessed by the various embodiments of the present application. Furthermore, the specific details disclosed herein are for purposes of illustration and understanding only, and are not intended to be limiting, as the application is not intended to be limited to the details disclosed herein as such.
The foregoing description has been presented for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the application to the form disclosed herein. Although a number of example aspects and embodiments have been discussed above, a person of ordinary skill in the art will recognize certain variations, modifications, alterations, additions, and subcombinations thereof.
Claims (10)
1. An epoxy resin electrical branch degradation observation system based on reflected light is characterized in that the system comprises,
the tested sample comprises an epoxy resin electric branch sample, a high-voltage needle electrode inserted into the epoxy resin electric branch sample and a ground electrode arranged at the bottom of the epoxy resin electric branch sample,
an experiment platform provided with an experiment cavity for accommodating a discharge medium,
a voltage source, which provides an adjustable voltage,
a voltage divider connected with the voltage source through a protection resistor to divide the adjustable voltage, wherein the measured sample flows in from the high-voltage needle electrode through the adjustable voltage and discharges to the ground electrode to generate an electric branch,
a reflection light source for irradiating the sample to be measured to generate reflection light with adjustable wavelength,
a CCD camera facing the sample to be measured to capture the reflected light image data,
a partial discharge instrument for detecting partial discharge signals in the discharge process of the sample to be detected,
and a processor connected to the CCD camera and the partial discharge meter to collect the reflected light image data and the partial discharge signal to evaluate the growth characteristics and the partial discharge characteristics of the electrical tree branches.
2. The epoxy electrical tree degradation observation system based on reflected light of claim 1, wherein preferably further comprising an oscilloscope for measuring an adjustable voltage, the processor being connected to the oscilloscope to correlate the adjustable voltage with the reflected light image data and the partial discharge signal.
3. The reflected light based epoxy electrical tree degradation observation system of claim 1, wherein the experiment table is provided with a transmission light source illuminating an experiment cavity, which is located at a side of the experiment cavity opposite to the CCD camera.
4. The reflected light based epoxy electrical tree degradation observation system of claim 1, wherein the voltage source is comprised of an ac voltage source, a dc voltage source, and a harmonic source.
5. The reflected light based epoxy electrical tree degradation observation system of claim 1, wherein the partial discharge meter measures the partial discharge signal using a combination of ultrasonic detection and pulse current method, and the processor analyzes the partial discharge characteristic based on the partial discharge signal.
6. The epoxy electrical tree branch degradation observation system based on reflected light of claim 1, wherein the reflected light source generates reflected light in the visible light band, the CCD camera is activated to capture reflected light images of the electrical tree branches, and the processor distinguishes between conductive electrical tree branches and non-conductive electrical tree branches based on the reflected light images; the processor is used for detecting the temperature difference of the internal structure of the conductive electrical branch based on the reflected light image; the reflected light source generates reflected light of ultraviolet light, the CCD camera is started to capture reflected light images of the electric branches, and the processor is used for detecting graphite carbon deposition based on the reflected light images.
7. The epoxy electrical tree degradation observation system based on reflected light of claim 1, wherein the reflected light source comprises a ring lamp and a wavelength adjustment device that adjusts the wavelength of the ring lamp.
8. The light-reflecting epoxy-based electrical dendrite degradation observing system of claim 1 wherein said test sample is immersed in said discharge medium comprising transformer oil, silicone oil, or insulating vegetable oil.
9. The reflected light based epoxy electrical tree degradation observation system of claim 1, wherein the sample under test comprises an epoxy impregnated paper or an epoxy electrical tree specimen.
10. An observation method of an epoxy resin electrical branch degradation observation system based on reflected light according to any one of claim 1 to 9, characterized by comprising the steps of,
preparing a tested sample, pouring epoxy resin and a curing agent into a three-necked flask according to a mass ratio of 100:85, mixing to form a mixture, placing the mixture into a stirrer, stirring in vacuum, uniformly mixing, and removing air in the mixture;
placing crepe paper in a mould and presetting an electrode, controlling the distance between the tip of a high-voltage needle electrode and a ground electrode to be 2+/-0.2 mm, pouring the mixture into the mould of the preset electrode, and solidifying at constant temperature after vacuum degassing treatment in a vacuum drying oven to obtain a tested sample;
the method comprises the steps that a measured sample is immersed in a discharge medium in an experimental cavity, the measured sample flows in from a high-voltage needle electrode through high-voltage electricity and discharges to a ground electrode to generate electric branches, a reflection light source irradiates the measured sample to generate reflection light with adjustable wavelength, a CCD camera faces the measured sample to capture image data of the reflection light, a partial discharge instrument detects partial discharge signals in the discharge process of the measured sample, and a processor is connected with the CCD camera and the partial discharge instrument to collect the image data of the reflection light and the partial discharge signals so as to evaluate the growth characteristics and the partial discharge characteristics of the electric branches, wherein the reflection light source generates reflection light with a visible light wave band, the CCD camera is started to capture the reflected light image of the electric branches, and the processor is used for distinguishing the conductive electric branches and the nonconductive electric branches based on the reflected light image; the processor is used for detecting the temperature difference of the internal structure of the conductive electrical branch based on the reflected light image; the reflected light source generates reflected light of ultraviolet light, the CCD camera is started to capture reflected light images of the electric branches, and the processor is used for detecting graphite carbon deposition based on the reflected light images.
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| CN202311847848.3A CN117805561A (en) | 2023-12-29 | 2023-12-29 | Epoxy resin electrical branch degradation observation system and method based on reflected light |
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| CN202311847848.3A CN117805561A (en) | 2023-12-29 | 2023-12-29 | Epoxy resin electrical branch degradation observation system and method based on reflected light |
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