A method for detecting and processing the oil status in natural ester insulating oil transformers

Abstract

The present invention belongs to the field of transformer technology, and specifically relates to a method for detecting and treating the oil condition in natural ester insulating oil transformers. This method includes an initialization step, a determination step, and a natural ester insulating oil treatment step. This method can simultaneously monitor the moisture and color of the natural ester insulating oil, enabling more efficient and convenient real-time detection of the degree of aging of the natural ester insulating oil. Furthermore, it can perform graded oil treatment based on different aging conditions, executing different treatment steps to more accurately treat the aging of the natural ester insulating oil and ensure the safe and reliable operation of the natural ester insulating oil transformer.

Description

Technical Field

[0001] The invention belongs to the technical field of transformers, and in particular relates to a method for detecting and processing the oil status in a natural ester insulating oil transformer. Background Art

[0002] In traditional transformer equipment, mineral insulating oil is widely used due to its excellent insulating and cooling properties and low price. In recent years, with increasing concern about ecological and environmental issues, natural ester insulating oil has gradually replaced mineral insulating oil as the insulating and cooling medium for transformers and has become widely used. When used in electrical equipment, natural ester insulating oil, due to its physical and chemical properties, is easily hygroscopic and, after the equipment is put into operation, impurities dissolve into the oil. When impurities or moisture enter the natural ester insulating oil, the dielectric loss of the insulating oil often increases, which has become an important indicator for determining whether the natural ester insulating oil is aging. However, the dielectric loss test of natural ester insulating oil is easily affected by the environment and equipment. First, the container containing the natural ester insulating oil must be thoroughly cleaned. Second, the dielectric loss test of natural ester insulating oil must be carried out at 80 or 90 degrees Celsius, which requires a long heating time. Therefore, the present invention can conveniently and quickly determine the dielectric loss of natural ester insulating oil by detecting its color, and thus the degree of aging of the natural ester insulating oil. After the degree of oil aging is detected, corresponding measures are taken to ensure the improvement of oil quality and the safe and reliable operation of natural ester insulating oil transformers. Summary of the Invention

[0003] The present invention aims to provide a method for detecting and treating the oil condition in natural ester insulating oil transformers. This method can more efficiently and simply detect the degree of aging of natural ester insulating oil in real time. It can also perform graded oil treatment on the natural ester insulating oil, performing different treatment steps based on the degree of aging of the natural ester insulating oil. This allows for more precise aging treatment of the natural ester insulating oil, ensuring the safe and reliable operation of natural ester insulating oil transformers.

[0004] In order to achieve the above object, the present invention adopts the following technical solution: a method for detecting and processing the oil status in a natural ester insulating oil transformer, comprising the following steps:

[0005] S1. Initial process: Start testing the oil in the natural ester insulating oil transformer;

[0006] S2, determination process;

[0007] The moisture content of the natural ester insulating oil is tested using the coulometric method, and the moisture test results are analyzed. If the moisture content of the natural ester insulating oil exceeds the standard, the process proceeds to step S3; if the moisture content of the natural ester insulating oil meets the requirements, the process returns to step S1;

[0008] At the same time, the natural ester insulating oil is subjected to colorimetric testing, and analysis is performed based on the colorimetric test results. If the colorimetric results meet the requirements, the process returns to step S1; if the colorimetric results do not meet the requirements, the process proceeds to step S3.

[0009] The moisture content of natural ester oil mainly reflects the sealing condition of the transformer and the aging status of solid insulating materials such as insulating paper, insulating cardboard, and resin immersed in the insulating oil. Judging the insulating oil condition based solely on this parameter may lead to misjudgment or omission of the insulating oil aging status. For example, if the moisture content in the oil is high but not exceeding the standard, the insulating oil may have aged to a considerable extent. However, since the transformer is well sealed and external moisture cannot penetrate, the moisture content has not exceeded the standard.

[0010] Chromaticity testing is mainly used to judge the aging status of natural ester insulating oil. After aging, the pigment in natural ester insulating oil will be destroyed. In addition, the influence of aging products will cause the chromaticity to change. The aging status of the insulating oil can be inferred based on this. However, the chromaticity will also be affected by the solid insulation immersed in the insulating oil. For example, the fibers of the insulating paper and the pigments in the resin may enter the insulating oil, causing the chromaticity of the insulating oil to change.

[0011] Therefore, the present invention combines the two parameters to judge the aging state of natural ester insulating oil, which has higher accuracy. Moreover, the two parameters are easier to be detected online, which can greatly reduce the cost of judging the aging state of natural ester insulating oil.

[0012] S3, natural ester insulating oil treatment process.

[0013] Furthermore, the natural ester insulating oil treatment process in step S3 includes the following steps:

[0014] S31, first processing step: oil filtering process, if the physical and chemical properties of the filtered natural ester insulating oil meet the requirements, then return to step S1; if the filtered natural ester insulating oil does not meet the requirements, then proceed to step S32;

[0015] S32, second treatment process: adsorbent treatment. If the physical and chemical properties of the natural ester insulating oil after adsorption treatment meet the requirements, the process returns to step S1; if not, the process proceeds to step S33;

[0016] S33, the third treatment process: oil change treatment process.

[0017] Generally, natural ester insulating oil transformers have a good sealing degree, so the impurity content in the insulating oil is relatively small. Through the first treatment process in step S3, natural ester insulating oil with high purity and low dielectric loss can basically be obtained.

[0018] Furthermore, in step S2, the colorimetry of the natural ester insulating oil is measured by visual comparison or spectrophotometry. Furthermore, the colorimetric value (APHA) is measured using an optical colorimeter. The present invention employs a method for determining the colorimetry of natural ester insulating oil to assess its aging. Compared to conventional detection techniques, this method eliminates manual sampling and heating steps, enabling simpler and more efficient detection and assessment of the aging of natural ester insulating oil. Furthermore, the present invention employs an integrated detection method, thereby avoiding the impact of environmental factors on oil degradation in conventional detection methods and improving the reliability of the test results.

[0019] Furthermore, the natural ester insulating oil treatment process in step S3 includes vacuum oil filtration and vacuum oil injection processes.

[0020] Furthermore, the oil filtering process in step S31 uses a filter processing method to filter impurities in the natural ester insulating oil.

[0021] Furthermore, the adsorbent in step S32 includes clay, activated carbon, silica gel, and activated alumina.

[0022] Furthermore, the physical and chemical property parameters of the natural ester insulating oil in steps S31 and S32 include dielectric loss measurement, volume resistivity, relative dielectric constant, and insulation breakdown voltage.

[0023] Traditional methods for detecting the oil condition in natural ester insulating oil transformers typically involve manual sampling, sample transportation, laboratory testing, and result feedback, often employing periodic testing. This creates the risk of oil degradation between testing points impacting the operational reliability of the natural ester insulating oil transformer. Furthermore, traditional oil change methods simply filter and change the oil without classifying it based on its aging state, sometimes resulting in a "slaughtering a nut" approach to management. The detection method proposed in the present invention offers simple, real-time monitoring, overcoming the shortcomings of traditional methods with discontinuous testing. It also adds a processing step for classifying and sorting the natural ester insulating oil based on its aging state, achieving a targeted, graded oil change that is energy-efficient and highly effective while meeting target requirements.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention combines a real-time detection scheme with a refined oil-changing process, thereby simultaneously providing functions for collecting real-time data on the color and moisture content of the natural ester insulating oil in the equipment, as well as a corresponding grading treatment method for aged natural ester insulating oil. This not only enables more efficient and convenient real-time detection of the degree of aging of the natural ester insulating oil, but also allows for simultaneous processing based on the detection results. Corresponding oil treatment steps are run according to the degree of aging of the natural ester insulating oil, thereby achieving refined management of the aged natural ester insulating oil. This avoids problems such as inaccurate measurements and technical waste in conventional aged natural ester insulating oil detection and oil treatment processes, achieves target requirements with energy efficiency, and ensures the safe and reliable operation of natural ester insulating oil transformers. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are for illustrative purposes only and are not to be construed as limitations on this patent. To better illustrate this embodiment, some components of the accompanying drawings may be omitted, enlarged, or reduced in size, and do not represent the actual dimensions of the product. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted from the accompanying drawings.

[0027] Figure 1 Schematic diagram of the process of detecting and treating the natural ester insulating oil transformer insulating oil of the present invention;

[0028] Figure 2 The figure is a schematic diagram of a system using the natural ester insulating oil transformer insulating oil detection and processing method of the present invention.

[0029] Among them, 1. Oil tank; 2. Natural ester insulating oil; 3. Pipe joint 1; 4. Valve 1; 5. Oil guide pipe 1; 6. Water-in-oil sensor; 7. Oil temperature sensor; 8. Optical analyzer; 9. Data transmission line; 10. Data monitoring system; 11. Valve 2; 12. Oil guide pipe 2; 13. Valve 3; 14. Oil guide pipe 3; 15. Pipe joint 2; 16. Valve 4; 17. Oil guide pipe 4; 18. Valve 5; 19. Oil guide pipe 5; 20. Oil filter; 21. Filter device; 22. Adsorbent grabbing device. DETAILED DESCRIPTION

[0030] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] Unless otherwise specified, the experimental methods used in the examples are conventional methods, and the materials and reagents used are all commercially available unless otherwise specified.

[0032] like Figure 1 As shown in the flowchart, step S1 begins testing the oil in the natural ester insulating oil transformer. Then, step S2 is executed as a determination step, using the coulometric method to test the moisture content of the natural ester insulating oil. The moisture test results are analyzed. If the moisture content of the natural ester insulating oil exceeds the standard, the process proceeds to step S3. If the moisture content of the natural ester insulating oil meets the requirements, the process returns to step S1. Simultaneously, the natural ester insulating oil is tested for colorimetry, using visual comparison or a spectrophotometer to measure the color. To shorten the measurement time, an optical colorimeter is preferably used to measure the colorimetric value (APHA) of the natural ester insulating oil. The APHA value is then used to determine the degree of aging. A higher APHA value indicates a higher degree of aging. If the detected APHA exceeds a set APHA threshold, meaning the oil is aged beyond the standard, the process proceeds to step S3 if the colorimetric result does not meet the requirements. If the colorimetric result meets the requirements, the process returns to step S1.

[0033] Furthermore, the first treatment process (step S31) in step S3 is executed, and an oil filtration process is used to remove impurities present in the natural ester insulating oil. After the oil filtration process is completed, the physical and chemical properties of the natural ester insulating oil, such as dielectric loss measurement, volume resistivity, relative dielectric constant, and insulation breakdown voltage, are measured. Based on the measured data results, it is determined whether the filtered natural ester insulating oil meets the corresponding index requirements. If not, the second treatment process of step S32 is executed; if it meets the corresponding index requirements, the treatment process is terminated at this time, and the aging evaluation process is then repeated starting from the measurement process of step S1.

[0034] Furthermore, the second treatment process of step S32 is executed, and an adsorbent treatment process is adopted to further treat the impurities in the natural ester insulating oil by adding adsorbent components such as white clay and activated carbon. Thereafter, the natural ester insulating oil after the adsorbent treatment is also subjected to dielectric loss measurement, volume resistivity, relative dielectric constant, insulation breakdown voltage and other physical and chemical properties to determine whether the natural ester insulating oil after the second treatment process meets the corresponding index requirements. If not, the final treatment process of step S33 is executed; if it meets the corresponding index requirements, the treatment process is terminated at this time, and the aging evaluation is then repeated starting from the measurement process of step S1.

[0035] Furthermore, the third processing step S33 is executed to perform an oil changing process on the natural ester insulating oil in the equipment, and the natural ester insulating oil is replaced by a vacuum oil filling process.

[0036] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A method for detecting and processing the oil status in a natural ester insulating oil transformer, characterized in that: The following steps are involved: S1. Initial process: Start testing the oil in the natural ester insulating oil transformer; S2, determination process; The moisture content of the natural ester insulating oil is tested using the coulometric method, and the moisture test results are analyzed. If the moisture content of the natural ester insulating oil exceeds the standard, the process proceeds to step S3; if the moisture content of the natural ester insulating oil meets the requirements, the process returns to step S1; At the same time, the natural ester insulating oil is subjected to colorimetric testing, and analysis is performed based on the colorimetric test results. If the colorimetric results meet the requirements, the process returns to step S1; if the colorimetric results do not meet the requirements, the process proceeds to step S3. S3, natural ester insulating oil treatment process.

2. The method for detecting and processing the oil status in a natural ester insulating oil transformer according to claim 1, characterized in that: The natural ester insulating oil treatment process in step S3 comprises the following steps: S31, first processing step: oil filtering process, if the physical and chemical properties of the filtered natural ester insulating oil meet the requirements, then return to step S1; if the filtered natural ester insulating oil does not meet the requirements, then proceed to step S32; S32, second treatment process: adsorbent treatment. If the physical and chemical properties of the natural ester insulating oil after adsorption treatment meet the requirements, the process returns to step S1; if not, the process proceeds to step S33; S33, the third treatment process: oil change treatment process.

3. The method for detecting and processing the oil status in a natural ester insulating oil transformer according to claim 1, characterized in that: In step S2, the colorimetry of the natural ester insulating oil is measured by visual comparison or spectrophotometry.

4. The method for detecting and processing the oil status in a natural ester insulating oil transformer according to claim 2, wherein: The oil filtering process in step S31 uses a filter processing method to filter impurities in the natural ester insulating oil.

5. The method for detecting and processing the oil status in a natural ester insulating oil transformer according to claim 2, characterized in that: The adsorbent in step S32 includes clay, activated carbon, silica gel or activated alumina.

6. The method for detecting and processing the oil status in a natural ester insulating oil transformer according to claim 2, characterized in that: The physical and chemical property parameters of the natural ester insulating oil in steps S31 and S32 include dielectric loss measurement, volume resistivity, relative dielectric constant and insulation breakdown voltage.

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