Determination method of moisture content of insulation paper

Abstract

The embodiment of the present invention discloses a method for determining the moisture content of insulating paper, the method comprising: obtaining a target insulating paper sample collected from a transformer and removing transformer oil; using a first dissolving reagent to dissolve the target insulating paper sample to obtain a pulp solution of the target insulating paper sample; using infrared spectroscopy and a standard curve to perform moisture content determination on the pulp solution to obtain a target moisture content of the target insulating paper sample, the standard curve being a curve of the relationship between the moisture concentration and the absorbance at the target wavenumber. The insulating paper sample from which the transformer oil has been removed is dissolved into a pulp solution by the above method, and the pulp solution is subjected to infrared spectroscopy for moisture content detection. After the transformer oil has been removed from the insulating paper, there is no extraction or other treatment process, so that the moisture content in the insulating paper is not affected by the environmental humidity or the problem of being unable to be accurately quantified due to the extraction process, thereby achieving complete quantification of the moisture content of the insulating paper, and the method is simple and quick.

Description

Technical Field

[0001] The invention relates to the field of measurement technology, and in particular to a method for measuring the moisture content of insulating paper. Background Art

[0002] The insulation inside the transformer is a composite insulation system composed of insulating oil and insulating paper. The insulating paper has irreplaceable and irreversible aging characteristics, which directly determines the service life of the transformer. On the one hand, moisture on the insulating paper will accelerate the aging process of the insulating paper and shorten the service life of the transformer; on the other hand, it will reduce the insulation strength of the transformer, causing equipment overheating or discharge failure, seriously affecting the safe operation of the power grid. Therefore, the moisture content of the insulating paper is a necessary parameter for judging the operating life of the transformer and analyzing equipment failures.

[0003] At present, the main methods for detecting the moisture content of insulating paper are Karl Fischer method and dew point method. Karl Fischer method requires methanol to extract the moisture in the insulating paper and then detect the moisture content of the methanol solution. Since there is a distribution balance between the moisture in the insulating paper and methanol, and the distribution balance is affected by temperature, it is impossible to completely extract the moisture in the paper, which will cause the final test result to deviate from the true value. The dew point method is suitable for the detection of new transformers that have been stored and transported by inflation or the detection of in-service transformers after oil drainage and inflation and drying. By detecting the moisture content of the gas inside the transformer, the moisture content in the insulating paper is inferred and calculated. This method is also affected by the distribution balance of moisture in the paper and in the dry gas, and it is not possible to take samples from the transformer for laboratory testing. It can only be tested on-site during transformer maintenance, which is time-consuming and labor-intensive, and there are many interference factors, and the quantitative accuracy is poor. The current method of using infrared spectroscopy to detect the moisture content of insulating paper is similar to the Karl Fischer method. It is necessary to extract the moisture in the insulating paper and then use infrared spectroscopy to detect the water content. This method also has the problem that the moisture cannot be accurately quantified due to the extraction process. Summary of the invention

[0004] The main purpose of the present invention is to provide a method for determining the moisture content of insulating paper, which can solve the problem of poor quantitative accuracy in determining the moisture content of insulating paper in the prior art.

[0005] To achieve the above object, the present invention provides a method for determining the moisture content of insulating paper in a first aspect, the method comprising:

[0006] Obtaining a target insulating paper sample, wherein the target insulating paper sample is an insulating paper sample collected from a transformer and from which transformer oil is removed;

[0007] Using a first dissolving reagent to dissolve the target insulating paper sample to obtain a pulp solution of the target insulating paper sample;

[0008] The moisture content of the pulp solution is measured by infrared spectroscopy using a standard curve to obtain a target moisture content of the target insulating paper sample. The standard curve is a curve showing the relationship between moisture concentration and absorbance at a target wave number.

[0009] In a feasible implementation, obtaining a target insulating paper sample includes:

[0010] Collecting an insulating paper sample from a first transformer oil of the transformer;

[0011] The insulating paper sample is placed in a second transformer oil for storage, wherein the second transformer oil is the same as the first transformer oil;

[0012] The stored insulating paper sample is subjected to grease removal treatment using a grease extractor and a grease extraction solvent to obtain the target insulating paper sample.

[0013] In a feasible implementation, the method further includes: performing infrared spectroscopy on the pulp solution to determine the moisture content of the target insulating paper sample using a standard curve to obtain the target moisture content of the target insulating paper sample;

[0014] configuring a plurality of second dissolving reagents with different water concentrations;

[0015] Using infrared spectroscopy and a preset sample pool to perform absorbance detection on each of the second dissolving reagents, respectively, to determine the absorbance characteristics of each of the second dissolving reagents, wherein the absorbance characteristics include a corresponding relationship between absorbance and wave number, and the sample pool is a reagent pool that is not affected by moisture;

[0016] The standard curve is established using the target wavenumber, the water concentration of each of the second dissolving reagents, and the target absorbance corresponding to the target wavenumber in the absorbance characteristic.

[0017] In a feasible implementation, the method of measuring the moisture content of the pulp solution by using infrared spectroscopy and a standard curve to obtain the target moisture content of the target insulating paper sample includes:

[0018] Using infrared spectroscopy to detect absorbance of the first dissolving reagent and the pulp solution respectively, to determine a first absorbance of the first dissolving reagent at a target wave number and a second absorbance of the pulp solution at a target wave number;

[0019] The target moisture content of the insulating paper sample is determined according to the mass of the target insulating paper sample, the standard curve, the first absorbance and the second absorbance.

[0020] In a feasible implementation, determining the target moisture content of the insulating paper sample according to the mass of the target insulating paper sample, the standard curve, the first absorbance, and the second absorbance includes the following mathematical expression:

[0021]

[0022] In the formula, A 样品 is the second absorbance, A 空白 is the first absorbance, a is the slope of the standard curve, b is the intercept of the standard curve, m 纸 is the mass of the target insulating paper sample, and w is the target moisture content of the insulating paper sample.

[0023] In a feasible implementation, the step of removing grease from the insulating paper sample using a grease extractor to obtain the target insulating paper sample further includes:

[0024] The target insulating paper sample is placed in a dry weighing bottle with a known mass for weighing, so as to determine the target mass of the target insulating paper sample.

[0025] In a possible implementation, the oil extractor comprises a Soxhlet extractor.

[0026] In a feasible implementation, the dissolving agent is copper ethylenediamine.

[0027] In a feasible implementation, the oil extraction solvent is pentane or n-hexane.

[0028] In a feasible implementation, the sample cell is a ZnSe sample cell.

[0029] The embodiments of the present invention have the following beneficial effects:

[0030] The present invention provides a method for determining the moisture content of insulating paper, the method comprising: obtaining a target insulating paper sample, the target insulating paper sample being an insulating paper sample collected from a transformer and having transformer oil removed; using a first dissolving reagent to dissolve the target insulating paper sample to obtain a pulp solution of the target insulating paper sample; using a standard curve to perform infrared spectroscopy on the pulp solution to determine the moisture content, to obtain a target moisture content of the target insulating paper sample, the standard curve being a curve of the relationship between the moisture concentration and the absorbance at the target wave number. By removing the transformer oil from the obtained insulating paper sample by the above method, the pulp solution is dissolved into a pulp solution, and the pulp solution is directly detected by infrared spectroscopy, so that the moisture content of the insulating paper can be completely quantified. Moreover, there is no extraction or other treatment process after the insulating paper is de-oiled from the transformer, and the moisture content is directly measured, so that the moisture content in the insulating paper is not affected by the environmental humidity or the problem of being unable to be accurately quantified due to the extraction process, and the method is simple and quick. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] in:

[0033] Figure 1 This is a flow chart of a method for determining moisture content of insulating paper in an embodiment of the present invention;

[0034] Figure 2 This is an infrared characteristic absorption peak spectrum of water in an embodiment of the present invention;

[0035] Figure 3 This is another flow chart of a method for determining moisture content of insulating paper in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments 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 creative work are within the scope of protection of the present invention.

[0037] See also Figure 1 , Figure 1 Flow chart of a method for determining moisture content of insulating paper according to an embodiment of the present invention, Figure 1 The method shown comprises the following steps:

[0038] 101. Obtain a target insulating paper sample, where the target insulating paper sample is an insulating paper sample collected from a transformer and from which transformer oil is removed;

[0039] It should be noted that the present application provides a method for determining the moisture content of insulating paper, wherein insulating paper and insulating oil constitute a composite insulation system of a transformer to achieve insulation inside the transformer. In order to achieve the measurement of the insulating paper inside the transformer, the first step is sampling, that is, collecting insulating paper samples. Furthermore, after obtaining the insulating paper samples, the present embodiment performs sample pre-treatment on the insulating paper samples so as to finally obtain the target insulating paper samples, wherein the target insulating paper samples are insulating paper samples collected from the transformer and the transformer oil is removed.

[0040] Exemplarily, a transformer insulation paper sample of no less than 1 g is taken, and the collected insulation paper sample reduces contact with the external environment of the transformer and reduces contact with the environment other than the transformer oil of the transformer, so as to reduce the impact of environmental humidity on the paper sample and remove the transformer oil of the insulation paper sample.

[0041] 102. Dissolve the target insulating paper sample using a first dissolving reagent to obtain a pulp solution of the target insulating paper sample;

[0042] Further, after obtaining the target insulating paper sample from which the transformer oil is removed, the target insulating paper sample is dissolved by a first dissolving agent to obtain a pulp solution of the target insulating paper sample, that is, after obtaining the target insulating paper sample from which the transformer oil is removed, the paper sample is dissolved into a pulp solution by step 102, wherein the dissolving agent is used to dissolve the insulating paper sample into a pulp solution. The dissolving agent includes but is not limited to solvents having the ability to dissolve paper samples, such as copper ethylenediamine, and is not limited to this example.

[0043] Exemplarily, the treated target insulating paper sample is immediately placed in a polyethylene dissolution bottle containing 40 mL of a 1 mol / L copper ethylenediamine solution, the residual air in the dissolution bottle is removed, the rubber stopper is plugged, and the dissolution bottle is stirred with an oscillator to dissolve the paper sample into pulp. The dissolution time is preferably 1.5 h to 2 h, thereby obtaining a pulp solution.

[0044] It should be noted that the terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order.

[0045] 103. Perform infrared spectroscopy on the water content of the pulp solution using a standard curve to obtain a target water content of the target insulating paper sample, wherein the standard curve is a curve showing the relationship between water concentration and absorbance at a target wave number.

[0046] In this embodiment, the moisture content of the insulating paper is detected by infrared spectroscopy. Specifically, the obtained pulp solution is subjected to infrared spectroscopy moisture content measurement and detection, and a curve of the relationship between the moisture concentration and the absorbance at the target wavenumber is predetermined as a standard curve for moisture content measurement. The standard curve reflects the relationship between the moisture concentration and the absorbance at the target wavenumber, and then the standard curve can be used to perform infrared spectroscopy moisture content measurement on the pulp solution to obtain the target moisture content of the target insulating paper sample. Exemplarily, the absorbance of the pulp solution at the target wavenumber can be measured by infrared spectroscopy, and the moisture concentration of the absorbance can be obtained by combining the relationship between the moisture concentration and the absorbance in the standard curve. The target moisture content of the target insulating paper sample can be analyzed based on the moisture concentration. Among them, the target wavenumber can be 3406cm-1 .

[0047] For further information, please refer to Figure 2 , Figure 2 is an infrared characteristic absorption peak spectrum of water in an embodiment of the present invention, Figure 2 It can be seen that the water content is 3406cm -1 The characteristic absorption peak at has the maximum absorbance, and in this embodiment, the target wave number is selected as 3406cm -1 The moisture content was corrected by the infrared characteristic absorption peak at , and a standard curve was established.

[0048] The present invention provides a method for determining the moisture content of insulating paper, the method comprising: obtaining a target insulating paper sample, the target insulating paper sample being an insulating paper sample collected from a transformer and having transformer oil removed; using a first dissolving reagent to dissolve the target insulating paper sample to obtain a pulp solution of the target insulating paper sample; using a standard curve to perform infrared spectroscopy on the pulp solution to determine the moisture content, to obtain a target moisture content of the target insulating paper sample, the standard curve being a curve of the relationship between the moisture concentration and the absorbance at the target wave number. By removing the transformer oil from the obtained insulating paper sample by the above method, the pulp solution is dissolved into a pulp solution, and the pulp solution is directly detected by infrared spectroscopy, so that the moisture content of the insulating paper can be completely quantified. Moreover, there is no extraction or other treatment process after the insulating paper is de-oiled from the transformer, and the moisture content is directly measured, so that the moisture content in the insulating paper is not affected by the environmental humidity or the problem of being unable to be accurately quantified due to the extraction process, and the method is simple and quick.

[0049] See also Figure 3 , Figure 3 FIG. 1 is another flow chart of a method for determining moisture content of insulating paper according to an embodiment of the present invention. Figure 3 The method shown comprises the following steps:

[0050] 301. Collect an insulating paper sample from the first transformer oil of the transformer;

[0051] 302. Preserve the insulating paper sample in a second transformer oil, wherein the second transformer oil is the same as the first transformer oil;

[0052] It should be noted that, in order to reduce the influence of the external environment on the moisture content of the insulating product in the present embodiment, after collecting the insulating paper sample in the first transformer oil of the transformer in step 301, the insulating paper sample needs to be placed in the second transformer oil that is the same as the first transformer oil for storage, so as to reduce the interference of the external environment on the moisture. Exemplarily, when collecting the insulating paper sample, the transformer oil can be directly collected inside the transformer where the insulating paper sample is located to reduce the change of its storage environment.

[0053] Exemplarily, take a transformer insulation paper sample of no less than 1g, and quickly store the taken insulation paper sample in a glass wide-mouth bottle filled with transformer oil. The paper sample needs to be completely immersed in the transformer oil to prevent the environmental humidity from affecting the paper sample. The transformer oil is the transformer oil of the transformer corresponding to the insulation paper sample.

[0054] 303. Using a grease extractor and a grease extraction solvent to remove grease from the stored insulating paper sample to obtain a target insulating paper sample;

[0055] The sample stored in transformer oil is subjected to grease removal treatment by a grease extractor and a grease extraction solvent to obtain a target insulating paper sample. Exemplarily, the grease extractor is a Soxhlet extractor, and the grease extraction solvent is pentane or n-hexane. The Soxhlet extractor is used to extract the insulating paper sample with pentane or n-hexane to remove the transformer oil adsorbed in the insulating paper to obtain the target insulating paper sample.

[0056] 304. Put the target insulating paper sample into a dry weighing bottle with known mass for weighing, so as to determine the target mass of the target insulating paper sample;

[0057] Further, the target mass of the target insulating paper sample is obtained through step 304, wherein the target mass is also the mass of the target insulating paper sample. For example, the target insulating paper sample is taken out of the Soxhlet extractor and quickly placed in a dry weighing bottle with a known mass, and the weighing bottle cap is covered. The weighing bottle containing the insulating paper sample is placed on an analytical balance, and the target mass m of the target insulating paper sample is accurately weighed and calculated. 纸 .

[0058] Among them, the target mass m 纸 The calculation can refer to the following mathematical expression:

[0059] m 纸 =m 总 -m 瓶 ;

[0060] In the formula, m 纸 -- Target mass (g);

[0061] m 总 --Mass obtained by weighing on an analytical balance (g);

[0062] m 瓶 --Weighing bottle mass (g).

[0063] 305. Dissolve the target insulating paper sample using a first dissolving reagent to obtain a pulp solution of the target insulating paper sample;

[0064] 306. Perform infrared spectroscopy on the water content of the pulp solution using a standard curve to obtain a target water content of the target insulating paper sample, wherein the standard curve is a curve showing the relationship between water concentration and absorbance at a target wave number.

[0065] It should be noted that steps 305 and 306 are Figure 1 The contents of steps 102 and 103 are similar, and are not described here to avoid repetition. For details, please refer to the contents of the aforementioned steps 102 and 103.

[0066] In a feasible implementation, before performing the water content determination by infrared spectroscopy, a standard curve needs to be established to obtain the water content by absorbance, so the following steps A1-A3 are also included before step 306:

[0067] A1. Preparing a plurality of second dissolving reagents with different water concentrations;

[0068] It should be noted that in order to obtain the relationship between different water concentrations and absorbance, and in the present application, a dissolving reagent is used to dissolve the sample into a pulp solution, therefore, a plurality of second dissolving reagents with different water concentrations are configured to obtain dissolving reagents with different water concentrations.

[0069] Exemplarily, copper ethylenediamine standard solutions with water contents of 250 mg / L, 500 mg / L, and 750 mg / L are prepared respectively. It can be understood that the concentration of copper ethylenediamine is consistent with the concentration of the sample pretreatment solution, that is, the concentration of the second dissolving reagent is consistent with the concentration of the first dissolving reagent in step 305. The above water concentration is only for example and is not specifically limited.

[0070] A2. Using infrared spectroscopy and a preset sample pool to perform absorbance detection on each of the second dissolving reagents, respectively, to determine the absorbance characteristics of each of the second dissolving reagents, wherein the absorbance characteristics include a corresponding relationship between absorbance and wave number, and the sample pool is a reagent pool that is not affected by moisture;

[0071] Exemplarily, the sample cell is a ZnSe sample cell.

[0072] A3. Establish the standard curve using the target wavenumber, the water concentration of each of the second dissolving reagents, and the target absorbance corresponding to the target wavenumber in the absorbance characteristic.

[0073] For example, steps A2-A3 may be to use a ZnSe sample cell or other sample cell that is not affected by moisture to test the above three standard solutions (second dissolving reagents) with different moisture concentrations, and select 3406 cm -1 The water content was corrected by the infrared characteristic absorption peak at 3406cm -1The maximum absorbance at the absorption peak is A 3400cm -1 The standard curve is established by using the concentration of the standard solution C as the ordinate and the concentration of the standard solution C as the abscissa. The standard curve can be expressed as formula (2):

[0074]

[0075] In the formula, A 3400cm -1 --The maximum absorbance of the absorption peak at 3400cm-1;

[0076] C--water concentration of standard solution (mg / L);

[0077] a--the slope of the standard curve;

[0078] b – The intercept of the standard curve.

[0079] In a feasible implementation, step 306 includes the following steps B1-B2:

[0080] B1. Using infrared spectroscopy to detect absorbance of the first dissolving reagent and the pulp solution respectively, to determine a first absorbance of the first dissolving reagent at a target wave number and a second absorbance of the pulp solution at a target wave number;

[0081] B2. Determine the target moisture content of the insulating paper sample according to the mass of the target insulating paper sample, the standard curve, the first absorbance and the second absorbance.

[0082] It should be noted that when performing sample determination, it is necessary not only to perform absorbance detection on the pulp solution, but also to perform absorbance detection on the first dissolving reagent, so as to obtain the first absorbance of the first dissolving reagent without dissolving the paper sample at the target wave number as a blank reference value, and the second absorbance of the pulp solution at the target wave number. Furthermore, the target moisture content of the insulating paper sample can be determined by the mass of the target insulating paper sample, the first absorbance, the second absorbance, and the standard curve.

[0083] That is, in the application, the water content of the pulp solution is directly measured by dissolving the paper sample into pulp, without extracting or otherwise treating the paper sample. Therefore, the subsequent measurement of the water content of the pulp solution will not be affected by the distribution equilibrium of water in the paper and in the dry gas or extract, and the water content of the paper sample can be fully quantified, with a simple test and small errors.

[0084] For example, the sample determination can refer to steps B1-B2, firstly, the water content of the copper ethylenediamine solution with a concentration of 1 mol / L is determined, and the first absorbance is obtained as the blank value A. 空白The treated pulp solution was measured under the same detection conditions as those used to establish the standard curve, and the 3406 cm -1 The maximum absorbance at the absorption peak is A 样品 , and then the second absorbance is substituted into the standard curve to calculate the water content of the sample solution. Finally, the target water content w of the insulating paper sample is calculated by the following formula:

[0085]

[0086] In the formula, A 样品 is the second absorbance, A 空白 is the first absorbance, a is the slope of the standard curve, b is the intercept of the standard curve, m 纸 is the mass of the target insulating paper sample, and w is the target moisture content of the insulating paper sample.

[0087] For example, to make the implementation of the present application clearer, the following inspection process may be referred to:

[0088] (1) Sampling

[0089] Take a transformer insulation paper sample of no less than 1g and quickly store it in a glass jar filled with transformer oil. The paper sample must be completely immersed in the transformer oil to prevent the environmental humidity from affecting the paper sample. The transformer oil is the same as the transformer oil of the transformer corresponding to the insulation paper.

[0090] (2) Sample pretreatment

[0091] Use a Soxhlet extractor to extract the insulating paper sample with pentane or n-hexane to remove the transformer oil adsorbed in the insulating paper. After taking out the treated insulating paper sample from the Soxhlet extractor, quickly put it into a dry weighing bottle with a known mass and cover the weighing bottle cap. Place the weighing bottle containing the insulating paper sample on an analytical balance, accurately weigh and calculate the sample mass m 纸 .

[0092] m 纸 =m 总 -m 瓶 (1)

[0093] Where: m 纸 --Mass of insulation paper sample (g)

[0094] m 总 --Mass obtained by weighing on analytical balance (g)

[0095] m 瓶 --Weighing bottle mass (g).

[0096] The weighed insulating paper sample is immediately placed in a polyethylene dissolution bottle containing 40 mL of 1 mol / L copper ethylenediamine solution. The residual air in the dissolution bottle is removed, the rubber stopper is plugged tightly, and the dissolution bottle is stirred with an oscillator to dissolve the paper sample into pulp. The dissolution time should be 1.5 h to 2 h.

[0097] (3) Establishing a standard curve

[0098] Prepare copper ethylenediamine standard solutions with water contents of 250 mg / L, 500 mg / L, and 750 mg / L respectively (the concentration of copper ethylenediamine is consistent with the concentration of sample pretreatment solution). Use a ZnSe sample cell or other sample cell that is not affected by water to test the above three standard solutions. Select 3406 cm -1 The water content was corrected by the infrared characteristic absorption peak at 3406cm -1 The maximum absorbance at the absorption peak is A 3400cm -1 The standard curve is established with the concentration of the standard solution C as the ordinate and the concentration of the standard solution C as the abscissa. The standard curve can be expressed as formula (2).

[0099]

[0100] In the formula, A 3400cm -1 3400cm -1 The maximum absorbance at the absorption peak; C--water concentration of the standard solution (mg / L); a--slope of the standard curve; b--intercept of the standard curve.

[0101] (4) Sample measurement

[0102] Before the sample is measured, the water content of the copper ethylenediamine solution with a concentration of 1 mol / L is measured to obtain the first absorbance as the blank value A. 空白 The treated pulp solution was measured under the same detection conditions as those used to establish the standard curve, and the 3406 cm -1 The maximum absorbance at the absorption peak is A 样品 Then, it is substituted into formula (2) as the second absorbance to calculate the water content of the sample solution. Finally, the moisture content of the insulating paper, i.e. the target moisture content w, is calculated by formula (3).

[0103]

[0104] In the formula, A 样品 is the second absorbance, A 空白 is the first absorbance, a is the slope of the standard curve, b is the intercept of the standard curve, m 纸 is the mass of the target insulating paper sample, and w is the target moisture content of the insulating paper sample.

[0105] The present invention provides a method for determining the moisture content of insulating paper, the method comprising: collecting an insulating paper sample from a first transformer oil of a transformer; placing the insulating paper sample in a second transformer oil for storage, the second transformer oil being the same as the first transformer oil; using a grease extractor and a grease extraction solvent to perform grease removal treatment on the stored insulating paper sample to obtain a target insulating paper sample; using a first dissolving reagent to perform dissolution treatment on the target insulating paper sample to obtain a pulp solution of the target insulating paper sample; using a standard curve to perform infrared spectroscopy water content determination treatment on the pulp solution to obtain a target moisture content of the target insulating paper sample, the standard curve being a curve of the relationship between moisture concentration and absorbance at a target wave number. By the above method, the obtained insulating paper sample is stored in the transformer oil in the same environment as the insulating paper in the transformer, reducing the influence of environmental humidity on the moisture content of the insulating paper, further, after removing the transformer oil, it is dissolved into a pulp solution, and the pulp solution is directly detected by infrared spectroscopy, so that the moisture content of the insulating paper can be completely quantified. After the transformer oil is removed from the insulation paper, there is no extraction or other treatment process, and the moisture content is directly measured, so that the moisture content in the insulation paper is not affected by the ambient humidity, and there is no problem of inaccurate quantification due to extraction treatment. The method is simple and fast. It is also suitable for the detection of moisture content of new insulation paper and insulation paper in operating transformers.

[0106] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0107] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0108] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for determining the moisture content of insulating paper, characterized in that: The method comprises: Obtaining a target insulating paper sample, wherein the target insulating paper sample is an insulating paper sample collected from a transformer and from which transformer oil is removed; Using a first dissolving reagent to dissolve the target insulating paper sample to obtain a pulp solution of the target insulating paper sample; Using a standard curve to perform infrared spectroscopy on the pulp solution to determine the moisture content, to obtain a target moisture content of the target insulating paper sample, wherein the standard curve is a curve showing a relationship between moisture concentration and absorbance at a target wave number; Wherein, obtaining the target insulating paper sample comprises: Collecting an insulating paper sample from a first transformer oil of the transformer; The insulating paper sample is placed in a second transformer oil for storage, wherein the second transformer oil is the same as the first transformer oil; Using a grease extractor and a grease extraction solvent to remove grease from the stored insulating paper sample to obtain the target insulating paper sample; The method of measuring the moisture content of the pulp solution by infrared spectroscopy and a standard curve to obtain the target moisture content of the target insulating paper sample includes: Using infrared spectroscopy to detect absorbance of the first dissolving reagent and the pulp solution respectively, to determine a first absorbance of the first dissolving reagent at a target wave number and a second absorbance of the pulp solution at a target wave number; Determining a target moisture content of the insulating paper sample according to the mass of the target insulating paper sample, the standard curve, the first absorbance, and the second absorbance; Wherein, determining the target moisture content of the insulating paper sample according to the mass of the target insulating paper sample, the standard curve, the first absorbance, and the second absorbance includes the following mathematical expression: In the formula, A 样品 is the second absorbance, A 空白 is the first absorbance, a is the slope of the standard curve, b is the intercept of the standard curve, m 纸 is the mass of the target insulating paper sample, and w is the target moisture content of the insulating paper sample.

2. The method according to claim 1, characterized in that: The method of using the standard curve to perform infrared spectroscopy on the pulp solution to determine the moisture content to obtain the target moisture content of the target insulating paper sample also includes: configuring a plurality of second dissolving reagents with different water concentrations; Using infrared spectroscopy and a preset sample pool to perform absorbance detection on each of the second dissolving reagents, respectively, to determine the absorbance characteristics of each of the second dissolving reagents, wherein the absorbance characteristics include a corresponding relationship between absorbance and wave number, and the sample pool is a reagent pool that is not affected by moisture; The standard curve is established using the target wavenumber, the water concentration of each of the second dissolving reagents, and the target absorbance corresponding to the target wavenumber in the absorbance characteristic.

3. The method according to claim 1, characterized in that: The step of removing grease from the insulating paper sample using a grease extractor to obtain the target insulating paper sample further comprises: The target insulating paper sample is placed in a dry weighing bottle with a known mass for weighing, so as to determine the target mass of the target insulating paper sample.

4. The method according to claim 1, characterized in that: The oil extractor is a Soxhlet extractor.

5. The method according to claim 1, characterized in that: The dissolving agent is copper ethylenediamine.

6. The method according to claim 1, characterized in that: The oil extraction solvent is pentane or n-hexane.

7. The method according to claim 2, characterized in that: The sample cell is a ZnSe sample cell.

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