CN110889234A - Aging life evaluation method for internal insulation oil paper of oil-immersed transformer - Google Patents
Aging life evaluation method for internal insulation oil paper of oil-immersed transformer Download PDFInfo
- Publication number
- CN110889234A CN110889234A CN201911224684.2A CN201911224684A CN110889234A CN 110889234 A CN110889234 A CN 110889234A CN 201911224684 A CN201911224684 A CN 201911224684A CN 110889234 A CN110889234 A CN 110889234A
- Authority
- CN
- China
- Prior art keywords
- oil
- insulation
- aging
- cellulose
- oil change
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Landscapes
- Housings And Mounting Of Transformers (AREA)
- Testing Resistance To Weather, Investigating Materials By Mechanical Methods (AREA)
Abstract
The invention discloses an oil-immersed transformer internal insulation oiled paper aging life evaluation method, belongs to the field of oiled paper insulation life evaluation, and provides an oiled paper insulation modelDPAnd kDPThe service life of oil paper insulation in the oil-immersed transformer under different oil change periods can be quantitatively analyzed, and the problem that in the prior art, only oil-immersed paperboards are analyzed, the influence of factors of the oil change periods on the aging service life is not considered, and the service life evaluation is not in accordance with actual working conditions is solved.
Description
Technical Field
The invention belongs to the field of oiled paper insulation life assessment, and particularly relates to an oil-immersed transformer internal insulation oiled paper aging life assessment method.
Background
The oil-immersed power transformer is an important link in the operation of a power grid, but due to the influence of a complex operation environment (moisture content, aging temperature and the like) all the year round, the oil paper insulation part in the oil-immersed power transformer is seriously aged, the insulation performance of the oil paper insulation part is greatly reduced, the stability of the power grid is seriously influenced, the service life of the oil-immersed power transformer depends on the aging degree of the oil paper insulation part in the oil paper insulation part, and the research on an evaluation algorithm for the aging life of the internal insulation of the high-voltage oil-immersed power transformer has important significance.
For oil-paper insulation equipment, the degree of reduction of the degree of polymerization of the insulation paper board becomes an important index for judging the service life of the equipment, but for oil-immersed power equipment, the aging degree of internal insulation is evaluated through sampling test, the service life is complex, the operation is not easy, the test result is more inaccurate due to the difference of temperature and moisture content, the measurement error is extremely large, quantitative analysis needs to be carried out on the degree of reduction of the insulation performance of the oil-paper in the oil-immersed power transformer, and therefore the service life of the oil-paper insulation equipment is accurately evaluated.
In the current stage, the power department evaluates an aging product in oil mainly by detecting substances such as furfural, water, gas and the like, a transformer can reduce the content of furfural and the like in the oil filtering process, the correctness of the aging evaluation of the transformer is greatly reduced due to the phenomenon, and the aging degree of an oil-immersed paperboard in the transformer cannot be visually represented; other research institutions predict the service life of the transformer through the polymerization degree of the oil-immersed paper board, a chemical kinetic model and the like, establish an aging kinetic equation of the aging of the oil-immersed paper board to indirectly calculate the insulation aging degree of the oil paper in the transformer, but influence of oil change conditions on the insulation aging state of the oil paper is not considered in numerous prediction models, so that how to consider field oil change factors to the insulation aging evaluation of the oil paper in the transformer is very important.
The invention patent CN 201310066515-a method for evaluating the aging state of oiled paper insulation, although the frequency-temperature translation theory is used and the activation energy is calculated through frequency-temperature translation, the method is mainly used for calculating the translation factor, the translation factor is expressed through the activation energy and the temperature, and further the dielectric loss curves at different temperatures are obtained, so that the influence of the temperature is eliminated. The patent mainly measures the dielectric spectrum in the aged state, and estimates the aged state by fitting the algebraic relation between the degree of polymerization and the dielectric constant and the dielectric loss.
The invention patent CN 201310134298-transformer oiled paper insulation aging evaluation and life prediction device and prediction method thereof measure polymerization degree indexes of aged transformer insulated paper and insulated paper board samples, perform mechanical strength test on the insulated paper, analyze furfural concentration change in oil in the insulating paper aging process, test moisture content in the paper and paper board aging process, and test gas content in the oil. The polymerization degree, the mechanical strength, the furfural, the water in the aging process and the gas in the oil are detected, and the service life is evaluated according to the parameters.
The invention patent CN 201810729552.4-an inside oil paper insulation life assessment algorithm of a high-voltage current transformer, although a frequency-temperature translation theory is used, only the activation energy of oil-immersed paper boards with different water contents is calculated by applying the algorithm, the invention patent mainly aims at the oil-immersed paper boards with different water contents, does not aim at oil paper insulation model calculation, and does not report the life assessment of the inside oil paper insulation of the oil-immersed transformer under different oil change periods at present, so that a novel technical scheme is urgently needed in the prior art to solve the problem.
Disclosure of Invention
In order to overcome the defects in the prior art: the invention provides an oil paper insulation model which can quantitatively analyze the service life of oil paper insulation in an oil-immersed transformer under different oil change periods and is used for solving the problem that in the prior art, only oil-immersed paperboards are analyzed, and the influence of factors of the oil change periods on the aging service life is not considered, so that the service life evaluation is not in line with the actual working condition.
In order to achieve the purpose, the invention adopts the technical scheme that: an evaluation method for the aging life of insulating oil paper in an oil-immersed transformer comprises the following steps which are sequentially carried out,
establishing a plurality of insulation model samples, wherein the insulation models are insulation models simulating oil change periods of oil-immersed transformers;
step two, performing medium loss tests of different oil change periods on the insulation model sample to obtain low-frequency translation factors α suitable for different oil change periods, and performing accelerated thermal aging of different oil change periods with set temperature on the insulation model sampleTesting to obtain a characterization parameter k of the cellulose degradation rateDPAnd the characteristic parameter w of the degradation and storage capacity of the polymerization degreeDPSaid k isDPAnd wDPK for establishing a quantitative relationship with an oil change cycleDPAnd wDP(ii) a The set temperature is lower than the flash point of insulating oil in the insulating model; the oil change cycle number value distribution selected in the dielectric loss test is the same as the oil change cycle number value distribution selected in the accelerated thermal aging test;
step three, utilizing the known cellulose loss accumulation mathematical model
Wherein: wDPCharacterized by cumulative loss of cellulose polymerization degree, DP is the cellulose polymerization degree at a set aging time point, DP0The degree of polymerization of the cellulose without aging, kDPIs a parameter characterizing the degradation rate of cellulose; wDPIs a characteristic parameter of polymerization degree degradation storage capacity, t is the aging life of the insulating oilpaper in the insulating model under the condition of accelerated thermal aging, e is a natural constant,
translating the aging life t of the insulating oil paper in the insulation model under the accelerated thermal aging condition with the low-frequency translation factor α to obtain the aging life t of the insulating oil paper in the oil-immersed transformer at the actual working temperatureFruit of Chinese wolfberryThe translation expression is: t is tSubstantial and substantialα ═ t, corrected cellulose loss cumulative mathematical model was obtained
Wherein: wDPCharacterized by cumulative loss of cellulose polymerization degree, DP is the cellulose polymerization degree at a set aging time point, DP0The degree of polymerization of the cellulose without aging, kDPIs a parameter characterizing the degradation rate of cellulose; wDPFor the characteristic parameter of polymerization degree degradation storage capacity, α is a low-frequency translation factor suitable for different oil change periods, e is a natural constant, tFruit of Chinese wolfberryIs an oil immersed type transformerThe aging life of the insulating oil paper in the transformer at the actual working temperature;
step four, inputting the value of the low-frequency translation factor α and the characterization parameter k of the cellulose degradation rate establishing the quantitative relation with the oil change periodDPAnd the characteristic parameter w of the degradation and storage capacity of the polymerization degreeDPThe corrected cellulose loss accumulation mathematical model ⑵ is given to obtain the actual aging life t of the insulation oil paper in the oil-immersed transformerFruit of Chinese wolfberryUsing equivalent translation model p ═ pSubstantial and substantialα, calculating and obtaining the aging life t of the internal insulation oil paper of the oil-immersed transformer at the actual working temperatureFruit of Chinese wolfberryRequired actual oil change period pFruit of Chinese wolfberryWherein p is the oil change period value selected in the accelerated thermal aging test in the step two, and α is a low frequency shift factor suitable for different oil change periods.
The insulation model is an oiled paper insulation model made of common insulation paper boards and 45# naphthenic transformer mineral insulation oil.
The low-frequency translation factor α suitable for different oil change periods in the step two is obtained by the following steps:
① testing the dielectric loss factors of the insulation model samples at different temperatures under the set oil change period and aging time, drawing corresponding dielectric loss factor curves, wherein each dielectric loss factor curve corresponds to a specific temperature, the different temperatures are 30 ℃, 50 ℃, 70 ℃ and 90 ℃,
②, performing low-frequency translation treatment on the dielectric loss factor curve of the insulation model sample, calculating and obtaining a translation factor of the insulation model sample translated to 30 ℃, calculating and obtaining the activation energy of the oil-impregnated paperboard in the insulation model according to a relational expression of the translation factor and the activation energy, wherein the relational expression of the translation factor and the activation energy is as follows:
wherein α is translation factor under the same water content, exp is exponential function with natural constant e as base, TrefIs a reference temperature in degrees Kelvin, T is trueTemperature in degrees kelvin,. delta.e is the activation energy of the oil impregnated paperboard, R is the gas molecular constant, R ═ 8.314 joules/(mol. kelvin);
③ changing oil change periods and aging times, repeating the step ②, calculating and obtaining the activation energy of the oil-immersed paper board of the insulation model under different oil change periods and aging times to obtain an activation energy average value, and obtaining low-frequency translation factors α suitable for different oil change periods by using the activation energy average value, wherein the different aging times are 15 days, 30 days, 45 days and 60 days.
In the second step, a characterization parameter k of the cellulose degradation rate establishing a quantitative relation with the oil change period is obtainedDPAnd the characteristic parameter w of the degradation and storage capacity of the polymerization degreeDPThe steps are as follows:
① executing accelerated thermal aging test of set temperature on the insulation model sample at different oil change periods, testing the DP value of the oil-immersed paper board in the insulation model every 15 days, and calculating and obtaining the accumulated loss W of the polymerization degree of celluloseDPNumerical value, plot WDPFitting a curve to the change of (c);
② cumulative loss W of cellulose polymerization degreeDPInputting the numerical value into a known cellulose loss accumulation mathematical model to obtain the parameter w under different oil change periodsDP、kDP；
③ fitting curves to the parameters w respectivelyDP、kDPPerforming exponential fitting with the oil change period to obtain a parameter w which establishes a quantitative relation with the oil change periodDP、kDP。
The set temperature for accelerated thermal aging in the second step is 130 ℃.
And the oil change cycle number value distribution selected in the dielectric loss test in the step two and the oil change cycle number value distribution selected in the accelerated thermal aging test are 5 days, 15 days and 30 days.
Through the design scheme, the invention can bring the following beneficial effects:
1. and carrying out translation calculation on the low-frequency section for representing the aging of the insulating paperboard in the oiled paper insulating model, and eliminating interference factors.
2. According to the oil paper insulation model structure of the transformer, the prediction of the oil paper insulation aging life inside the oil-immersed transformer in different oil change periods is realized, the structure is compact, and the experimental conditions are optimized;
3. obtaining a parameter w having a quantitative relationship with an oil change periodDPAnd kDPThe service life evaluation is more accurate and more in line with the actual working condition.
Drawings
Fig. 1 is a flow chart of the method for evaluating the aging life of the internal insulation oilpaper of the oil-immersed transformer.
FIG. 2 is a dielectric loss factor curve of an oil paper insulation model sample aged for 30 days with an oil change period of 30 days at different test temperatures in the example of the present invention.
FIG. 3 is a curve showing the change of dielectric loss tangent at 50 deg.C, 70 deg.C and 90 deg.C in the low frequency range shifted to 30 deg.C in the embodiment of the present invention.
FIG. 4 shows the cumulative loss W of the degree of polymerization of the cellulose in the oil-impregnated paper board in the oil-paper insulation model for different oil change periods in the embodiment of the present inventionDPAnd changing the fitted curve.
Detailed Description
The following detailed description of the embodiments of the invention is provided in connection with the accompanying drawings
Shown in attached figures 1-4: an evaluation method for the aging life of insulating oil paper in an oil-immersed transformer comprises the following steps which are sequentially carried out,
establishing a plurality of insulation model samples, wherein the insulation models can simulate the oil change period of an oil-immersed transformer;
secondly, performing medium loss tests of different oil change periods on the insulation model sample to obtain low-frequency translation factors α suitable for the different oil change periods, performing accelerated thermal aging tests of different oil change periods at set temperature on the insulation model sample to obtain a characterization parameter k of cellulose degradation rateDPAnd the characteristic parameter w of the degradation and storage capacity of the polymerization degreeDPSaid k isDPAnd wDPK for establishing a quantitative relationship with an oil change cycleDPAnd wDP(ii) a The deviceThe constant temperature is lower than the flash point of the insulating oil in the insulating model; the oil change cycle number value distribution selected in the dielectric loss test is the same as the oil change cycle number value distribution selected in the accelerated thermal aging test;
step three, utilizing the known cellulose loss accumulation mathematical model
Wherein: wDPCharacterized by cumulative loss of cellulose polymerization degree, DP is the cellulose polymerization degree at a set aging time point, DP0The degree of polymerization of the cellulose without aging, kDPIs a parameter characterizing the degradation rate of cellulose; wDPIs a characteristic parameter of polymerization degree degradation storage capacity, t is the aging life of the insulating oilpaper in the insulating model under the condition of accelerated thermal aging, e is a natural constant,
translating the aging life t of the insulating oil paper in the insulation model under the accelerated thermal aging condition with the low-frequency translation factor α to obtain the aging life t of the insulating oil paper in the oil-immersed transformer at the actual working temperatureFruit of Chinese wolfberryThe translation expression is: t is tSubstantial and substantialα ═ t, corrected cellulose loss cumulative mathematical model was obtained
Wherein: wDPCharacterized by cumulative loss of cellulose polymerization degree, DP is the cellulose polymerization degree at a set aging time point, DP0The degree of polymerization of the cellulose without aging, kDPIs a parameter characterizing the degradation rate of cellulose; wDPFor the characteristic parameter of polymerization degree degradation storage capacity, α is a low-frequency translation factor suitable for different oil change periods, e is a natural constant, tFruit of Chinese wolfberryThe aging life of the insulation oilpaper in the oil-immersed transformer at the actual working temperature is prolonged;
step four, inputting the value of the low-frequency translation factor α and the characterization parameter k of the cellulose degradation rate establishing the quantitative relation with the oil change periodDPAnd degradation of degree of polymerizationCharacteristic parameter w of storage capacityDPThe corrected cellulose loss accumulation mathematical model ⑵ is given to obtain the actual aging life t of the insulation oil paper in the oil-immersed transformerFruit of Chinese wolfberryUsing equivalent translation model p ═ pSubstantial and substantialα, calculating and obtaining the aging life t of the internal insulation oil paper of the oil-immersed transformer at the actual working temperatureFruit of Chinese wolfberryRequired actual oil change period pFruit of Chinese wolfberryWherein p is the oil change period value selected in the accelerated thermal aging test in the step two, and α is a low frequency shift factor suitable for different oil change periods.
The insulation model is an oiled paper insulation model made of common insulation paper boards and 45# naphthenic transformer mineral insulation oil.
The low-frequency translation factor α suitable for different oil change periods in the step two is obtained by the following steps:
① testing the dielectric loss factors of the insulation model sample at different temperatures under the set oil change period and aging time, drawing corresponding dielectric loss factor curves, wherein each dielectric loss factor curve corresponds to a specific temperature;
②, performing low-frequency translation treatment on the dielectric loss factor curve of the insulation model sample, calculating and obtaining a translation factor of the insulation model sample translated to 30 ℃, calculating and obtaining the activation energy of the oil-impregnated paperboard in the insulation model according to a relational expression of the translation factor and the activation energy, wherein the relational expression of the translation factor and the activation energy is as follows:
wherein α is translation factor under the same water content, exp is exponential function with natural constant e as base, TrefIs a reference temperature in degrees kelvin, T is an actual temperature in degrees kelvin, Δ E is an activation energy of the oil-impregnated paperboard, R is a gas molecular constant, R is 8.314 joules/(mol. kelvin);
③, changing the oil change period and the aging time, repeating the step ②, calculating and obtaining the activation energy of the oil-immersed paper board of the insulation model under different oil change periods and aging times, obtaining an activation energy average value, and obtaining the low-frequency translation factor α suitable for different oil change periods by utilizing the activation energy average value.
The different temperatures in the step ① are 30 ℃, 50 ℃, 70 ℃ and 90 ℃, and the different aging times in the step ③ are selected to be 15 days, 30 days, 45 days and 60 days.
In the second step, a characterization parameter k of the cellulose degradation rate establishing a quantitative relation with the oil change period is obtainedDPAnd the characteristic parameter w of the degradation and storage capacity of the polymerization degreeDPThe steps are as follows:
① executing accelerated thermal aging test of set temperature on the insulation model sample at different oil change periods, testing the DP value of the oil-immersed paper board in the insulation model every 15 days, and calculating and obtaining the accumulated loss W of the polymerization degree of celluloseDPNumerical value, plot WDPFitting a curve to the change of (c);
② cumulative loss W of cellulose polymerization degreeDPInputting the numerical value into a known cellulose loss accumulation mathematical model to obtain the parameter w under different oil change periodsDP、kDP；
③ fitting curves to the parameters w respectivelyDP、kDPPerforming exponential fitting with the oil change period to obtain a parameter w which establishes a quantitative relation with the oil change periodDP、kDP。
The set temperature for accelerated thermal aging in the second step is 130 ℃.
And the oil change cycle number value distribution selected in the dielectric loss test in the step two and the oil change cycle number value distribution selected in the accelerated thermal aging test are 5 days, 15 days and 30 days.
The method comprises the following steps of manufacturing a plurality of oil paper insulation models by using common insulation paper boards and 45# naphthenic transformer mineral insulation oil under laboratory conditions, wherein the oil paper insulation models are vacuum containers with inlets and outlets, and the common insulation paper boards and the 45# naphthenic transformer mineral insulation oil are contained in the vacuum containers. The inlet and outlet of the container facilitate oil change.
The dielectric loss factor curves of different oil change periods (5 days, 15 days and 30 days) and different aging times (15 days, 30 days, 45 days and 60 days) are measured at different temperatures (30 ℃, 50 ℃, 70 ℃ and 90 ℃) on the oil paper insulation model.
Taking a dielectric loss factor curve of an oil paper insulation model sample with an oil change period of 30 days and aging for 30 days as an example, the dielectric loss factor curves at different temperatures are shown in figure 2, a plurality of dielectric loss factor curves are tested at the same temperature to obtain an average value, the low-frequency sections of the dielectric loss factor curves at 50 ℃, 70 ℃ and 90 ℃ are translated to 30 ℃ to calculate the translation factors, the translation curves are shown in figure 3, the activation energy of the oil-impregnated paper board in the oil paper insulation model is calculated according to the translation factors, the method for calculating the activation energy of the oil-impregnated paper board in the oil paper insulation model is repeated to obtain the activation energy of the oil-impregnated paper board of the oil paper insulation model in different oil change periods (5 days, 15 days and 30 days), the average value of delta E is 99 +/-10 kJ/mol, and the low-frequency translation factor α suitable for different oil change periods is obtained
Wherein T isrefIs a reference temperature in degrees kelvin; t is the actual temperature in degrees Kelvin,
in the test, three groups of insulation model samples with different oil change periods are subjected to an accelerated thermal aging test at the temperature of 130 ℃, the DP value of the degree of polymerization of an oil-immersed paperboard in the insulation model is tested every 15 days, and the accumulated loss W of the degree of polymerization of cellulose is calculatedDPNumerical value, plot WDPFitting a curve to the change of (2) to accumulate the polymerization degree of cellulose to be lost WDPThe values are input into a known cumulative mathematical model of cellulose loss,
obtaining the parameter w under different oil change periodsDP、kDPSeparately aligning the parameters w by fitting curvesDP、kDPPerforming exponential fitting on the oil change period to obtain a parameter w related to the oil change periodDP、kDP. The fitting equation is as follows:
w* DP＝13.43exp(-p/1.692)+0.952
kDP＝-0.0535exp(-p/4.946)+0.031
wherein: p is characterized as the oil change period under aging conditions at 130 ℃.
Using known mathematical models of cellulose loss accumulation
Translating the aging life t of the insulating oil paper in the insulation model under the accelerated thermal aging condition with the low-frequency translation factor α to obtain the aging life t of the insulating oil paper in the oil-immersed transformer at the actual working temperatureFruit of Chinese wolfberryThe translation expression is: t is tFruit of Chinese wolfberryX α ═ t, corrected accumulated mathematical model of cellulose loss was obtained
Inputting a low-frequency translation factor α value and a characterization parameter k of cellulose degradation rate establishing a quantitative relation with an oil change periodDPCharacteristic parameter w of polymerization degradation storage capacityDPThe numerical value of the total loss of the corrected cellulose is used for a mathematical model, and then the insulation life of the transformer oil paper under different oil change periods is predicted, wherein the life calculation equation is as follows:
and T is the actual working temperature of the oil-immersed transformer.
Using equivalent translation model p ═ pFruit of Chinese wolfberryX α, calculating and obtaining the aging life t of the internal insulation oil paper of the oil-immersed transformer at the actual working temperatureFruit of Chinese wolfberryRequired actual oil change period pFruit of Chinese wolfberryWherein p is the accelerated heat aging in the second stepThe oil change period value selected in the chemical test is α low-frequency translation factors suitable for different oil change periods through the service life evaluation algorithm, the service life of the transformer which can be operated is about 31.3 years when the oil change period is oil change every 3.5 years and the operation temperature is 70 ℃.
It is to be understood that the above-described embodiments are only some, and not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Claims (7)
1. An oil immersed transformer internal insulation oilpaper aging life assessment method is characterized in that: comprises the following steps which are sequentially carried out,
establishing a plurality of insulation model samples, wherein the insulation models are insulation models simulating oil change periods of oil-immersed transformers;
secondly, performing medium loss tests of different oil change periods on the insulation model sample to obtain low-frequency translation factors α suitable for the different oil change periods, performing accelerated thermal aging tests of different oil change periods at set temperature on the insulation model sample to obtain a characterization parameter k of cellulose degradation rateDPAnd the characteristic parameter w of the degradation and storage capacity of the polymerization degreeDPSaid k isDPAnd wDPK for establishing a quantitative relationship with an oil change cycleDPAnd wDP(ii) a The set temperature is lower than the flash point of insulating oil in the insulating model; the oil change cycle number value distribution selected in the dielectric loss test is the same as the oil change cycle number value distribution selected in the accelerated thermal aging test;
step three, utilizing the known cellulose loss accumulation mathematical model
Wherein: wDPCharacterized by cumulative loss of the degree of polymerization of the cellulose, and DP is the cellulose at a set aging time pointDegree of polymerization, DP0The degree of polymerization of the cellulose without aging, kDPIs a parameter characterizing the degradation rate of cellulose; wDPIs a characteristic parameter of polymerization degree degradation storage capacity, t is the aging life of the insulating oilpaper in the insulating model under the condition of accelerated thermal aging, e is a natural constant,
translating the aging life t of the insulating oil paper in the insulation model under the accelerated thermal aging condition with the low-frequency translation factor α to obtain the aging life t of the insulating oil paper in the oil-immersed transformer at the actual working temperatureFruit of Chinese wolfberryThe translation expression is: t is tSubstantial and substantialα ═ t, corrected cellulose loss cumulative mathematical model was obtained
Wherein: wDPCharacterized by cumulative loss of cellulose polymerization degree, DP is the cellulose polymerization degree at a set aging time point, DP0The degree of polymerization of the cellulose without aging, kDPIs a parameter characterizing the degradation rate of cellulose; wDPFor the characteristic parameter of polymerization degree degradation storage capacity, α is a low-frequency translation factor suitable for different oil change periods, e is a natural constant, tFruit of Chinese wolfberryThe aging life of the insulation oilpaper in the oil-immersed transformer at the actual working temperature is prolonged;
step four, inputting the value of the low-frequency translation factor α and the characterization parameter k of the cellulose degradation rate establishing the quantitative relation with the oil change periodDPCharacteristic parameter w of degradation of storage capacity by degree of polymerizationDPThe corrected cellulose loss accumulation mathematical model ⑵ is given to obtain the actual aging life t of the insulation oil paper in the oil-immersed transformerFruit of Chinese wolfberryUsing equivalent translation model p ═ pSubstantial and substantialα, calculating and obtaining the aging life t of the internal insulation oil paper of the oil-immersed transformer at the actual working temperatureFruit of Chinese wolfberryRequired actual oil change period pFruit of Chinese wolfberryWherein p is the oil change period value selected in the accelerated thermal aging test in the step two, and α is a low frequency shift factor suitable for different oil change periods.
2. The method for evaluating the aging life of the internal insulation oilpaper of the oil-immersed transformer according to claim 1, wherein the method comprises the following steps: the insulation model is an oiled paper insulation model made of common insulation paper boards and 45# naphthenic transformer mineral insulation oil.
3. The method for evaluating the aging life of the internal insulation oilpaper of the oil-immersed transformer according to claim 1, wherein the low-frequency translation factor α applicable to different oil change periods in the second step is obtained by the following steps:
① testing the dielectric loss factors of the insulation model sample at different temperatures under the set oil change period and aging time, drawing corresponding dielectric loss factor curves, wherein each dielectric loss factor curve corresponds to a specific temperature;
②, performing low-frequency translation treatment on the dielectric loss factor curve of the insulation model sample, calculating and obtaining a translation factor of the insulation model sample translated to 30 ℃, calculating and obtaining the activation energy of the oil-impregnated paperboard in the insulation model according to a relational expression of the translation factor and the activation energy, wherein the relational expression of the translation factor and the activation energy is as follows:
α is the translation factor under the same water content, exp is the exponential function with natural constant e as the base, TrefIs a reference temperature in degrees kelvin, T is an actual temperature in degrees kelvin, Δ E is an activation energy of the oil-impregnated paperboard, R is a gas molecular constant, R is 8.314 joules/(mol. kelvin);
③, changing the oil change period and the aging time, repeating the step ②, calculating and obtaining the activation energy of the oil-immersed paper board of the insulation model under different oil change periods and aging times, obtaining an activation energy average value, and obtaining the low-frequency translation factor α suitable for different oil change periods by utilizing the activation energy average value.
4. The method for evaluating the aging life of the internal insulation oilpaper of the oil-immersed transformer according to claim 3, wherein the different temperatures in the step ① are 30 ℃, 50 ℃, 70 ℃ and 90 ℃, and the different aging times in the step ③ are selected from 15 days, 30 days, 45 days and 60 days.
5. The method for evaluating the aging life of the internal insulation oilpaper of the oil-immersed transformer according to claim 1, wherein the method comprises the following steps: in the second step, a characterization parameter k of the cellulose degradation rate establishing a quantitative relation with the oil change period is obtainedDPAnd the characteristic parameter w of the degradation and storage capacity of the polymerization degreeDPThe steps are as follows:
① executing accelerated thermal aging test of set temperature on the insulation model sample at different oil change periods, testing the DP value of the oil-immersed paper board in the insulation model every 15 days, and calculating and obtaining the accumulated loss W of the polymerization degree of celluloseDPNumerical value, plot WDPFitting a curve to the change of (c);
② cumulative loss W of cellulose polymerization degreeDPInputting the numerical value into a known cellulose loss accumulation mathematical model to obtain the parameter w under different oil change periodsDP、kDP；
③ fitting curves to the parameters w respectivelyDP、kDPPerforming exponential fitting with the oil change period to obtain a parameter w which establishes a quantitative relation with the oil change periodDP、kDP。
6. The method for evaluating the aging life of the internal insulation oilpaper of the oil-immersed transformer according to claim 1, wherein the method comprises the following steps: the set temperature for accelerated thermal aging in the second step is 130 ℃.
7. The method for evaluating the aging life of the internal insulation oilpaper of the oil-immersed transformer according to claim 1, wherein the method comprises the following steps: and the oil change cycle number value distribution selected in the dielectric loss test in the step two and the oil change cycle number value distribution selected in the accelerated thermal aging test are 5 days, 15 days and 30 days.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911224684.2A CN110889234B (en) | 2019-12-04 | 2019-12-04 | Aging life evaluation method for internal insulation oil paper of oil-immersed transformer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911224684.2A CN110889234B (en) | 2019-12-04 | 2019-12-04 | Aging life evaluation method for internal insulation oil paper of oil-immersed transformer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110889234A true CN110889234A (en) | 2020-03-17 |
| CN110889234B CN110889234B (en) | 2023-04-07 |
Family
ID=69750289
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911224684.2A Active CN110889234B (en) | 2019-12-04 | 2019-12-04 | Aging life evaluation method for internal insulation oil paper of oil-immersed transformer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110889234B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111596181A (en) * | 2020-05-28 | 2020-08-28 | 华北电力大学（保定） | Transformer solid insulation aging evaluation method based on bubble escape temperature |
| CN112014702A (en) * | 2020-08-31 | 2020-12-01 | 广西大学 | Method for evaluating aging state of transformer insulating paper after oil change |
| CN112924788A (en) * | 2020-12-31 | 2021-06-08 | 广东电网有限责任公司电力科学研究院 | Early warning method and device for short circuit accumulation effect of transformer |
| CN114778606A (en) * | 2022-04-25 | 2022-07-22 | 国网黑龙江省电力有限公司电力科学研究院 | Assessment method for transient distribution of oilpaper insulation moisture migration in composite electric field |
| CN115238865A (en) * | 2022-07-19 | 2022-10-25 | 贵州电网有限责任公司 | Electric-heating combined life assessment model construction method for power transformer |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102722193A (en) * | 2012-06-25 | 2012-10-10 | 甘景福 | Method for slowing down aging of solid insulation of oil-paper insulating transformer |
| CN103149452A (en) * | 2013-03-01 | 2013-06-12 | 中国南方电网有限责任公司超高压输电公司贵阳局 | Method for evaluating ageing state of paper oil insulation |
| CN103245519A (en) * | 2013-04-17 | 2013-08-14 | 华北电力大学 | Device and method for evaluating oil paper insulation aging and predicting service life of transformer |
| CA3006890A1 (en) * | 2015-12-01 | 2017-06-08 | General Electric Technology Gmbh | An intelligent assessment method of main insulation condition of transformer oil paper insulation |
| CN107894444A (en) * | 2017-11-10 | 2018-04-10 | 哈尔滨理工大学 | A kind of Oil-Paper Insulation moisture content fitting algorithm |
| CN108872814A (en) * | 2018-07-05 | 2018-11-23 | 国网吉林省电力有限公司电力科学研究院 | A kind of high-tension current inductor inside paper oil insulation lifetime estimation method |
| CN110009236A (en) * | 2019-04-10 | 2019-07-12 | 哈尔滨理工大学 | A kind of oil-immersed power transformer built-in electrical insulation degree of aging quantitative evaluating method |
-
2019
- 2019-12-04 CN CN201911224684.2A patent/CN110889234B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102722193A (en) * | 2012-06-25 | 2012-10-10 | 甘景福 | Method for slowing down aging of solid insulation of oil-paper insulating transformer |
| CN103149452A (en) * | 2013-03-01 | 2013-06-12 | 中国南方电网有限责任公司超高压输电公司贵阳局 | Method for evaluating ageing state of paper oil insulation |
| CN103245519A (en) * | 2013-04-17 | 2013-08-14 | 华北电力大学 | Device and method for evaluating oil paper insulation aging and predicting service life of transformer |
| CA3006890A1 (en) * | 2015-12-01 | 2017-06-08 | General Electric Technology Gmbh | An intelligent assessment method of main insulation condition of transformer oil paper insulation |
| US20190041450A1 (en) * | 2015-12-01 | 2019-02-07 | Yandong LV | An intelligent assessment method of main insulation condition of transformer oil paper insulation |
| CN107894444A (en) * | 2017-11-10 | 2018-04-10 | 哈尔滨理工大学 | A kind of Oil-Paper Insulation moisture content fitting algorithm |
| CN108872814A (en) * | 2018-07-05 | 2018-11-23 | 国网吉林省电力有限公司电力科学研究院 | A kind of high-tension current inductor inside paper oil insulation lifetime estimation method |
| CN110009236A (en) * | 2019-04-10 | 2019-07-12 | 哈尔滨理工大学 | A kind of oil-immersed power transformer built-in electrical insulation degree of aging quantitative evaluating method |
Non-Patent Citations (2)
| Title |
|---|
| H. -Z. DING Æ Z. D. WANG: "On the degradation evolution equations of cellulose", 《SPRINGER》 * |
| 张明泽、刘骥: "换油周期对变压器油纸绝缘老化性能影响规律", 《电工技术学报》 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111596181A (en) * | 2020-05-28 | 2020-08-28 | 华北电力大学（保定） | Transformer solid insulation aging evaluation method based on bubble escape temperature |
| CN111596181B (en) * | 2020-05-28 | 2022-05-06 | 华北电力大学（保定） | Transformer solid insulation aging evaluation method based on bubble escape temperature |
| CN112014702A (en) * | 2020-08-31 | 2020-12-01 | 广西大学 | Method for evaluating aging state of transformer insulating paper after oil change |
| CN112924788A (en) * | 2020-12-31 | 2021-06-08 | 广东电网有限责任公司电力科学研究院 | Early warning method and device for short circuit accumulation effect of transformer |
| CN114778606A (en) * | 2022-04-25 | 2022-07-22 | 国网黑龙江省电力有限公司电力科学研究院 | Assessment method for transient distribution of oilpaper insulation moisture migration in composite electric field |
| CN115238865A (en) * | 2022-07-19 | 2022-10-25 | 贵州电网有限责任公司 | Electric-heating combined life assessment model construction method for power transformer |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110889234B (en) | 2023-04-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110889234B (en) | Aging life evaluation method for internal insulation oil paper of oil-immersed transformer | |
| CN108872814B (en) | Method for evaluating insulation life of oil paper in high-voltage current transformer | |
| CN110009236B (en) | Quantitative evaluation method for internal insulation aging degree of oil-immersed power transformer | |
| CN103149452B (en) | Method for evaluating ageing state of paper oil insulation | |
| CN109239546B (en) | Transformer insulation life prediction and reliability test method | |
| CN106855605B (en) | Frequency domain test analysis system and method for evaluating overall aging life of cable | |
| CN108680613B (en) | Method for evaluating moisture content in insulating paper by using initial slope of complex dielectric constant | |
| Lin et al. | Effect of oil replacement on furfural analysis and aging assessment of power transformers | |
| CN110297167A (en) | A kind of transformer ageing state evaluation method based on Multi-source Information Fusion | |
| CN108828413B (en) | Quantitative evaluation method for aging of transformer insulating paperboard based on dielectric response characteristic | |
| CN108872820B (en) | Method and system for evaluating insulation aging state of oil impregnated paper in high-voltage current transformer | |
| CN107862114A (en) | Small echo PSO SVM Diagnosis Method of Transformer Faults based on three ratio feature amounts | |
| CN107860894B (en) | Method for predicting furfural content in transformer insulating oil based on frequency domain complex dielectric constant initial slope | |
| CN102759690A (en) | Method for judging insulation aging degrees of alternating current (AC) cables | |
| CN108089038B (en) | Test device and method for analyzing influence of winding defect heating on oil paper insulation performance | |
| CN112557834B (en) | Aging diagnosis method for oiled paper insulation equipment based on Raman spectrum | |
| CN104914364A (en) | Capacitance oilpaper transformer sleeve insulation state assessment method | |
| CN107941862A (en) | A kind of transformer oil Aging of Oil-paper Insulation in Oil diagnostic system based on frequency domain dielectric response | |
| CN110286303A (en) | A kind of coaxial cable insulation cable ageing state appraisal procedure based on BP neural network | |
| CN106248912A (en) | A kind of characterizing method of transformer oil ageing | |
| CN112269105A (en) | Moisture prediction and aging evaluation method for field bushing oil-immersed cellulose insulation | |
| Silva et al. | Noninvasive ageing assessment by means of polarization and depolarization currents analysis and its correlation with moisture content for power transformer life management | |
| Chen et al. | An improved method of detection and concentration of methanol in oil-paper insulation | |
| CN112666232A (en) | Frequency domain dielectric response prediction method for oil-immersed cellulose insulating materials with different temperatures and humidities | |
| CN112082930A (en) | Method for diagnosing aging state of solid insulation of transformer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |