Method and system for aging detection of natural ester insulating oil transformer insulation system

Abstract

This invention relates to the field of transformer technology and discloses an aging detection method and system for the insulation system of a natural ester insulating oil transformer. The method includes collecting oil temperature data, trace moisture content, and colorimetric data of the insulating oil in the natural ester insulating oil transformer insulation system; performing aging analysis on the insulating paper in the natural ester insulating oil transformer insulation system based on the oil temperature data and the trace moisture content to obtain aging degree data of the insulating paper; performing aging analysis on the insulating oil based on the colorimetric data to obtain aging degree data of the insulating oil; and analyzing the aging degree of the natural ester insulating oil transformer insulation system based on the aging degree data of the insulating paper and the aging degree data of the insulating oil to obtain aging analysis results. This invention can simply and efficiently detect the aging degree of transformers, improving the safety and stability of transformer operation.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, and in particular to an aging detection method and system for the insulation system of a natural ester insulating oil transformer. Background Technology

[0002] Currently, many power transformers in my country's power grid system are nearing or exceeding their service life. Due to cost considerations, these transformers are still in operation. A problem they face is that as the insulation ages, the electrical and mechanical properties of the insulation materials gradually decline, significantly reducing the transformer's insulation performance and short-circuit withstand capability, thus affecting its operational safety and reliability. While natural ester-insulated oil transformers are not widely used and have a short application history, with the formulation of my country's dual-carbon targets, their use will be gradually promoted. Therefore, research on the aging of natural ester-insulated oil transformers is necessary. The aging of liquid-immersed transformers is mainly caused by the aging of the insulating oil and insulating paper. However, detecting the aging degree of insulating paper is difficult and time-consuming. Therefore, using insulating paper to infer the aging degree of transformers is not only costly but also inefficient. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides an aging detection method and system for the insulation system of a natural ester insulating oil transformer. This method solves the problems of high detection difficulty and long detection cycle, and enables online analysis of the aging degree of the insulation system of the natural ester insulating oil transformer, achieving the effect of real-time monitoring of the aging of the insulation system.

[0004] In a first aspect, the present invention provides an aging detection method for the insulation system of a transformer using natural ester insulating oil, the method comprising:

[0005] Data on oil temperature, trace water content, and color of insulating oil in the insulation system of a natural ester insulating oil transformer were collected.

[0006] Based on the oil temperature data and the trace moisture content, the aging analysis of the insulating paper in the insulation system of the natural ester insulating oil transformer was performed to obtain the aging degree data of the insulating paper.

[0007] The aging analysis of the insulating oil is performed based on the colorimetric data to obtain the aging degree data of the insulating oil;

[0008] Based on the aging data of the insulating paper and the insulating oil, the aging degree of the insulation system of the natural ester insulating oil transformer is analyzed, and the aging analysis results are obtained.

[0009] Furthermore, the step of performing aging analysis on the insulating paper in the natural ester insulating oil transformer insulation system based on the oil temperature data and the trace moisture content includes:

[0010] Based on the oil temperature data, the corresponding water content threshold is obtained, and the difference between the trace water content and the water content threshold is calculated.

[0011] Based on the difference, the aging degree data of the insulating paper in the insulation system of the natural ester insulating oil transformer are obtained.

[0012] Furthermore, the step of obtaining the corresponding water content threshold based on the oil temperature data includes:

[0013] Obtain the equilibrium state curve of micro-water content between insulating oil and insulating paper in the insulation system of the natural ester insulating oil transformer at a given temperature;

[0014] Based on the equilibrium curve, the water content threshold corresponding to the oil temperature data is obtained.

[0015] Furthermore, the step of performing aging analysis on the insulating oil based on the chromaticity data includes:

[0016] Based on the chromaticity data, the corresponding dielectric loss data is obtained;

[0017] Based on the dielectric loss data, the aging degree data of the insulating oil is obtained.

[0018] Further, the step of obtaining the corresponding dielectric loss data based on the chromaticity data includes:

[0019] Obtain the relationship curve between the color of the insulating oil and the dielectric damage in the insulation system of the natural ester insulating oil transformer;

[0020] Based on the relationship curve, the dielectric loss data corresponding to the chromaticity data is obtained.

[0021] Furthermore, the method also includes:

[0022] The aging analysis results of the insulation system of the natural ester insulating oil transformer are compared with the aging threshold. If the aging threshold is reached, an aging alarm is issued.

[0023] In a second aspect, the present invention provides an aging detection system for the insulation system of a natural ester insulating oil transformer, comprising a natural ester insulating oil transformer, the aging detection system further comprising:

[0024] A data acquisition module and an aging analysis module are sequentially connected to the natural ester insulating oil transformer.

[0025] The data acquisition module is used to collect the oil temperature data, trace water content and color data of the insulating oil in the insulation system of the natural ester insulating oil transformer;

[0026] The aging analysis module is used to perform aging analysis on the insulating paper in the insulation system of the natural ester insulating oil transformer based on the oil temperature data and the trace moisture content, to obtain aging degree data of the insulating paper; to perform aging analysis on the insulating oil based on the color data, to obtain aging degree data of the insulating oil; and to analyze the aging degree of the insulation system of the natural ester insulating oil transformer based on the aging degree data of the insulating paper and the aging degree data of the insulating oil, to obtain aging analysis results.

[0027] Furthermore, the data acquisition module is connected to the pipe joint on the oil tank of the natural ester insulating oil transformer via connecting pipes and valves, and the data acquisition module is connected to the aging analysis module via a data transmission line.

[0028] Furthermore, the data acquisition module includes: an oil temperature sensor, a micro-water sensor, and a spectrophotometer.

[0029] Furthermore, the aging analysis module also includes:

[0030] The aging warning module is used to compare the aging analysis results of the insulation system of the natural ester insulating oil transformer with the aging threshold. If the aging threshold is reached, an aging alarm is issued.

[0031] The present invention provides an aging detection method and system for the insulation system of a natural ester insulating oil transformer. This method utilizes effective data on oil temperature, trace amounts of water in the oil, and color values ​​to perform online analysis of the aging degree of the insulation system, thereby enabling real-time monitoring of the aging process. This not only improves the efficiency and accuracy of transformer aging detection but also enhances the safety and stability of transformer operation. Attached Figure Description

[0032] Figure 1 This is a schematic flowchart of an aging detection method for the insulation system of a natural ester insulating oil transformer provided in an embodiment of the present invention;

[0033] Figure 2 yes Figure 1 A flowchart illustrating step S20;

[0034] Figure 3 yes Figure 1 A flowchart illustrating step S30;

[0035] Figure 4This is a curve showing the relationship between the color and dielectric loss data of a certain rapeseed-based natural ester insulating oil provided in an embodiment of the present invention;

[0036] Figure 5 This is a schematic diagram of the aging detection system for the insulation system of a natural ester insulating oil transformer provided in an embodiment of the present invention;

[0037] Figure 6 This is a schematic diagram of the structural connection relationship of an aging detection system for the insulation system of a natural ester insulating oil transformer provided in an embodiment of the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Please see Figure 1 The first embodiment of the present invention provides an aging detection method for the insulation system of a natural ester insulating oil transformer, comprising steps S10 to S40:

[0040] Step S10: Collect oil temperature data, trace water content and color data of the insulating oil in the insulation system of the natural ester insulating oil transformer.

[0041] In existing natural ester-insulated oil-immersed transformers, the insulation system includes insulating oil and cellulose insulating paper. The aging of liquid-immersed transformers is mainly caused by the aging of insulating oil and insulating paper. However, it is difficult to directly detect the aging degree of the insulating paper and the detection cycle is long. Therefore, this invention proposes to infer the aging degree of insulating oil and insulating paper by analyzing the insulating oil, thereby inferring the aging degree of the transformer, so as to improve detection efficiency and reduce detection costs.

[0042] In the process of analyzing insulating oil, the relevant data of insulating oil used in the embodiments of the present invention include oil temperature data, trace water content and color data. The oil temperature data of insulating oil can be collected by an oil temperature sensor, the trace water content of insulating oil can be collected by a trace water sensor, and the color data of insulating oil can be collected by an optical analyzer. These data can be collected by conventional sensors or equipment, and will not be described in detail here.

[0043] Step S20: Based on the oil temperature data and the trace moisture content, perform aging analysis on the insulating paper in the insulation system of the natural ester insulating oil transformer to obtain the aging degree data of the insulating paper.

[0044] Since it is difficult to directly test the aging of insulating paper, this embodiment of the invention uses data from insulating oil to deduce the aging degree of insulating paper. Therefore, it is first necessary to confirm the correlation between the aging degree of insulating oil and insulating paper.

[0045] In reality, the water-holding capacity of the insulating oil in a liquid-immersed transformer increases significantly with rising oil temperature. Therefore, the water content in the oil is always measured based on data from a specific temperature. The trace amounts of water within the transformer are primarily dissolved in the insulating oil and cellulose insulating paper. When the temperature is maintained at a constant level, the water content between the insulating oil and the insulating paper reaches an equilibrium. As the aging degree of the insulating paper increases, more molecular bonds break, leading to a decrease in its moisture-retaining capacity. Therefore, for the same water content in the paper, a higher degree of aging in the insulating paper results in a higher water content in the insulating oil. Based on this relationship between the insulating oil and the insulating paper, we can derive the following... Figure 2 The steps for insulating paper aging analysis are shown below:

[0046] Step S201: Based on the oil temperature data, obtain the corresponding water content threshold and calculate the difference between the trace water content and the water content threshold.

[0047] Step S202: Based on the difference, obtain the aging degree data of the insulating paper in the insulation system of the natural ester insulating oil transformer.

[0048] First, based on the relationship between the insulating oil and the insulating paper in the transformer, an equilibrium curve of the trace moisture content between the insulating oil and the insulating paper at a given temperature can be obtained. This equilibrium curve allows us to obtain the trace moisture content at different oil temperatures. We use this equilibrium trace moisture content as a moisture content threshold and then calculate the difference between the collected trace moisture content and the moisture content threshold. Clearly, the larger the difference, the greater the moisture content in the insulating oil, meaning the higher the degree of aging of the insulating paper. This method provides a simple and efficient way to detect the degree of aging of the insulating paper.

[0049] Step S30: Perform aging analysis on the insulating oil based on the colorimetric data to obtain the degree of aging of the insulating oil.

[0050] After obtaining the aging degree of the insulating paper, we also need to analyze the aging degree of the insulating oil. In oil-immersed electrical equipment such as transformers, cables, and capacitors, natural ester insulating oil has been increasingly widely used due to increasingly stringent environmental requirements. However, when used in electrical equipment, natural ester insulating oil is prone to moisture absorption due to its physicochemical properties, and impurities dissolve into the oil after the equipment is put into operation. Especially in oil-immersed power transformers with natural ester insulation, the intrusion of impurities or moisture into the natural ester insulating oil often leads to an increase in dielectric loss, which becomes an important indicator for judging whether the natural ester insulating oil has aged. However, the dielectric loss detection of natural ester insulating oil is easily affected by the environment and equipment. First, the container holding the natural ester insulating oil needs to be thoroughly cleaned; second, the dielectric loss measurement of natural ester insulating oil needs to be carried out at 80 or 90 degrees Celsius, requiring a relatively long heating time for the natural ester insulating oil.

[0051] For the reasons mentioned above, this invention employs a method to determine the dielectric loss of natural ester insulating oil by detecting its color, and subsequently, its degree of aging. Compared to directly measuring the dielectric loss of the insulating oil, this method improves the efficiency of the determination. The steps are as follows: Figure 3 As shown:

[0052] Step S301: Obtain the corresponding dielectric loss data based on the chromaticity data.

[0053] Step S302: Based on the dielectric loss data, obtain the aging degree data of the insulating oil.

[0054] This invention first tests the APHA (Advanced Percentage Harmony) chromaticity reference value of the natural ester insulating oil at the time of manufacture. Then, during the production, commissioning, and maintenance of natural ester insulating oil-immersed transformers, the aging degree of the natural ester insulating oil (2) is determined by testing its chromaticity. In reality, the chromaticity deviation of each oil-based natural ester insulating oil during aging is different. The IEEE Guide for Acceptance and Maintenance of Natural Ester Insulating Liquid stipulates that the dielectric loss of unused natural ester insulating oil should not exceed 4%. Therefore, we can pre-obtain the relationship curve between the chromaticity and dielectric damage data of insulating oils of different oil bases. For example... Figure 4 The curve showing the relationship between the chromaticity and dielectric loss data of a certain rapeseed-based natural ester insulating oil demonstrates how the dielectric loss of the insulating oil can be easily derived from the collected chromaticity data.

[0055] In other words, we obtained the correlation between the APHA of natural ester insulating oil and the dielectric loss, which is an indicator of the aging of natural ester insulating oil. Specifically, the higher the APHA of natural ester insulating oil, the higher the dielectric loss value of natural ester insulating oil. The method of inferring the degree of aging of insulating oil using colorimetric data in this invention is not only simple but also efficient.

[0056] Step S40: Based on the aging data of the insulating paper and the aging data of the insulating oil, analyze the aging degree of the insulation system of the natural ester insulating oil transformer to obtain the aging analysis results.

[0057] The detection method of this invention first assesses the aging state of the insulating paper based on the equilibrium curve of the micro-moisture content between the insulating oil and the insulating paper at a given temperature. Then, it assesses the aging state of the insulating oil through colorimetric detection. Finally, it combines the aging data of the insulating paper and the insulating oil to estimate the aging degree of the transformer insulation system. This method is not only convenient but also allows for rapid and effective real-time detection of the transformer, improving the safety and stability of transformer operation.

[0058] Step S50: Compare the aging degree of the insulation system of the natural ester insulating oil transformer with the aging threshold. If the aging degree reaches the aging threshold, an aging alarm is issued.

[0059] To further improve the safety of transformers, this invention also provides an early warning function. When the detected aging level reaches or exceeds a preset warning value, an alarm will be issued immediately, prompting relevant personnel to maintain the transformer in a timely manner, such as by degassing and filtering the oil or changing the oil, thereby further improving the safety and stability of transformer operation.

[0060] This embodiment provides an aging detection method for the insulation system of a natural ester insulating oil transformer. Compared with traditional methods, which have the problems of difficult and long cycle for aging detection of insulating paper and complicated steps for dielectric loss detection of insulating oil, this invention uses effective data on oil temperature, trace water in the oil, and color values ​​to perform online analysis of the aging degree of the insulation system of the natural ester insulating oil transformer. It can simply and efficiently detect the aging degree of the transformer, improve the safe operation level of the transformer, and detect defects in advance, thereby extending the life cycle of the transformer and further improving the economic operating efficiency.

[0061] Please see Figure 5 Based on the same inventive concept, the second embodiment of the present invention proposes an aging detection system for the insulation system of a natural ester insulating oil transformer, comprising a natural ester insulating oil transformer, and the aging detection system further comprising:

[0062] The data acquisition module 10 and the aging analysis module 20 are connected in sequence to the natural ester insulating oil transformer.

[0063] The data acquisition module is used to collect the oil temperature data, trace water content and color data of the insulating oil in the insulation system of the natural ester insulating oil transformer;

[0064] The aging analysis module is used to perform aging analysis on the insulating paper in the insulation system of the natural ester insulating oil transformer based on the oil temperature data and the trace moisture content, to obtain aging degree data of the insulating paper; to perform aging analysis on the insulating oil based on the color data, to obtain aging degree data of the insulating oil; and to analyze the aging degree of the insulation system of the natural ester insulating oil transformer based on the aging degree data of the insulating paper and the aging degree data of the insulating oil, to obtain aging analysis results.

[0065] The following is an example Figure 6 The connection diagram of the aging detection system shown below illustrates the specific connection relationships between the system modules of this invention:

[0066] The natural ester insulating oil transformer 1 contains natural ester insulating oil 2. The pipe joint 3 of its oil tank is connected to a valve 4 and a connecting pipe 5, thereby realizing the connection between the natural ester insulating oil transformer 1 and the data acquisition module 10. The data acquisition module 10 includes a micro water sensor 6, an oil temperature sensor 7 and an optical analyzer 8. The data acquisition module 10 is connected to the aging analysis module 20 through a data transmission line 9.

[0067] Through the above connection, the natural ester insulating oil 2 can enter the data acquisition module 10 through the pipe joint 3 and the connecting pipe 5 to collect data. The valve 4 is normally open, and the data collected by the data acquisition module 10 is sent to the aging analysis module 20 for aging analysis through the data transmission line 9.

[0068] Furthermore, the aging analysis module 20 also includes:

[0069] The aging warning module 204 is used to compare the aging analysis results of the insulation system of the natural ester insulating oil transformer with the aging threshold. If the aging threshold is reached, an aging alarm is issued.

[0070] The technical features and effects of the aging detection system for the insulation system of natural ester insulating oil transformers proposed in this invention are the same as those of the method proposed in this invention, and will not be repeated here. Each module in the above-mentioned aging detection system for the insulation system of natural ester insulating oil transformers can be implemented entirely or partially through software, hardware, or a combination thereof. Each module can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0071] In summary, the aging detection method and system for the insulation system of a natural ester insulating oil transformer proposed in this invention involves: collecting oil temperature data, trace water content, and colorimetric data of the insulating oil in the natural ester insulating oil transformer insulation system; performing aging analysis on the insulating paper in the natural ester insulating oil transformer insulation system based on the oil temperature data and the trace water content to obtain aging degree data of the insulating paper; performing aging analysis on the insulating oil based on the colorimetric data to obtain aging degree data of the insulating oil; and analyzing the aging degree data of the insulating paper and the insulating oil to obtain the aging analysis result. This invention performs online analysis of the aging degree of the natural ester insulating oil transformer insulation system through effective data on oil temperature, trace water content in the oil, and colorimetric values, enabling simple and efficient detection of the transformer's aging degree and improving the safety and stability of transformer operation.

[0072] The various embodiments in this specification are described in a progressive manner. For directly identical or similar parts of the embodiments, refer to each other. Each embodiment focuses on its differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. It should be noted that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0073] The embodiments described above are merely preferred embodiments of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various improvements and substitutions without departing from the technical principles of this invention, and these improvements and substitutions should also be considered within the scope of protection of this application. Therefore, the scope of protection of this patent application should be determined by the scope of the claims.

Claims

1. A method for detecting aging of a natural ester insulating oil transformer insulation system, characterized by, The method comprises the following steps: Collecting oil temperature data, micro water content data and colorimetric data of insulation oil in a natural ester insulation oil transformer insulation system; Performing aging analysis on insulation paper in the natural ester insulation oil transformer insulation system according to the oil temperature data and the micro water content data to obtain aging degree data of the insulation paper; Performing aging analysis on the insulation oil according to the colorimetric data to obtain aging degree data of the insulation oil; Analyzing the aging degree of the natural ester insulation oil transformer insulation system according to the aging degree data of the insulation paper and the aging degree data of the insulation oil to obtain an aging analysis result; The step of performing aging analysis on the insulation paper in the natural ester insulation oil transformer insulation system according to the oil temperature data and the micro water content data comprises the following steps: Obtaining a corresponding water content threshold value according to the oil temperature data, and calculating a difference value between the micro water content and the water content threshold value; Obtaining aging degree data of the insulation paper in the natural ester insulation oil transformer insulation system according to the difference value; The step of performing aging analysis on the insulation oil according to the colorimetric data comprises the following steps: Obtaining corresponding dielectric loss data according to the colorimetric data; Obtaining aging degree data of the insulation oil according to the dielectric loss data; The step of obtaining a corresponding water content threshold value according to the oil temperature data comprises the following steps: Obtaining an equilibrium state curve of micro water content between insulation oil and insulation paper in the natural ester insulation oil transformer insulation system at a given temperature; Obtaining a corresponding water content threshold value according to the oil temperature data according to the equilibrium state curve.

2. The method for detecting aging of a natural ester insulating oil transformer insulation system according to claim 1, characterized by, The step of obtaining corresponding dielectric loss data according to the colorimetric data comprises the following steps: Obtaining a relationship curve between colorimetric data and dielectric loss of insulation oil in the natural ester insulation oil transformer insulation system; Obtaining corresponding dielectric loss data according to the colorimetric data according to the relationship curve.

3. The method for detecting aging of a natural ester insulating oil transformer insulation system according to claim 1, characterized by, The method further comprises the following steps: Comparing the aging analysis result of the natural ester insulation oil transformer insulation system with an aging threshold value, and issuing an aging warning if the aging threshold value is reached.

4. A system for detecting aging of a natural ester insulating oil transformer insulation system, the system for detecting aging being applied to the method according to any one of claims 1 to 3, comprising a natural ester insulating oil transformer, characterized in that, The aging detection system further comprises the following steps: A data acquisition module and an aging analysis module connected in sequence with the natural ester insulation oil transformer; The data acquisition module is used to collect oil temperature data, micro water content data and colorimetric data of insulation oil in the natural ester insulation oil transformer insulation system; The aging analysis module is used to perform aging analysis on insulation paper in the natural ester insulation oil transformer insulation system according to the oil temperature data and the micro water content data to obtain aging degree data of the insulation paper, perform aging analysis on the insulation oil according to the colorimetric data to obtain aging degree data of the insulation oil, and analyze the aging degree of the natural ester insulation oil transformer insulation system according to the aging degree data of the insulation paper and the aging degree data of the insulation oil to obtain an aging analysis result.

5. The aging detection system for natural ester insulating oil transformer insulation system according to claim 4, characterized in that, The data acquisition module is connected with a pipe joint on an oil tank of the natural ester insulation oil transformer through a joint pipe and a valve, and the data acquisition module is connected with the aging analysis module through a data transmission line.

6. The aging detection system for natural ester insulating oil transformer insulation system according to claim 4, characterized in that, The data acquisition module comprises an oil temperature sensor, a micro water sensor and a spectrophotometric detector.

7. The aging detection system for natural ester insulating oil transformer insulation system according to claim 6, characterized in that, The aging analysis module further comprises: An aging early warning module is configured to compare the aging analysis result of the natural ester insulating oil transformer insulation system with an aging threshold value, and issue an aging warning if the aging threshold value is reached.

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