CN1226994A - Method for evaluating deterioration of insulating paper - Google Patents
Method for evaluating deterioration of insulating paper Download PDFInfo
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- CN1226994A CN1226994A CN 97196970 CN97196970A CN1226994A CN 1226994 A CN1226994 A CN 1226994A CN 97196970 CN97196970 CN 97196970 CN 97196970 A CN97196970 A CN 97196970A CN 1226994 A CN1226994 A CN 1226994A
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- insulating paper
- degree
- polymerization
- temperature
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Abstract
Insulating paper immersed in oil is deteriorated by heating the paper to a temperature below 110 in the operation temperature region of oil-filled electric apparatus and the rates of generation of carbon dioxide and carbon monoxide which generate when the insulating paper dissolved in insulating oil is thermally decomposed are estimated from the amounts of gases and the degree of polymerization lowering as the insulating paper deteriorates. The deterioration characteristic of the insulating paper is evaluated from the change of the degree of polymerization with time and the dependence of the rates of generation of the gases on the temperature. Since the deterioration of the insulating paper over 110 degree is different from that below 110 degree and the deterioration characteristic of the insulating paper on the low temperature side can be evaluated accurately.
Description
Technical field
The present invention relates to a kind of evaluation method of deterioration of insulating paper.More particularly, The present invention be more particularly directed to a kind of useful life, and estimate the method for its deterioration of insulating paper in operating temperature for oil immersion electrical equipment such as definite oil-immersed type transformer, liquid immersed reactors.
Background of invention
During insulating paper performance generation deterioration in the insulating oil, though the decline of its breakdown voltage is very little, the reduction of its mechanical strength is very big.In oil immersion electrical equipment such as transformer, reactor, when external short circuit takes place, in the big electromagnetic and mechanical power of the inner generation of electrical equipment.Therefore, the viewpoint that reduces from mechanical strength can be according to the useful life of inferring electrical equipment as (performance) degradation of the insulating paper of insulated electric conductor.
The degradation of insulating paper can be by the tension stress of measuring insulating paper, the degree of polymerization etc., or is estimated by its degradation speed of observation.Again, people also study, and measure the component content of the furfural that generated by deterioration of insulating paper, acetaldehyde, acetone, carbon dioxide, CO (carbon monoxide converter) gas etc., estimate the degradation of insulating paper by this.
The evaluation method of above-mentioned deterioration of insulating paper was undertaken by carry out activated deterioration test under the high temperature about 100-200 ℃ in the past.Usually, because oil immersion electrical equipment turns round, the operating temperature (usually 110 ℃ below) of its activated deterioration test data extrapolation at high temperature to oil immersion electrical equipment thus, can be able to be predicted the degradation of the insulation property of insulating paper below 110 ℃ temperature.
Aforesaid with below the high temperature activated deterioration test data extrapolation to 110 ℃, infer that thus the method for deterioration of insulating paper then can produce following problem.
Water (H
2O) and methane (CH
4) molecular weight identical all be 18, but the boiling point of water is 100 ℃, and the boiling point of methane is-164 ℃, both boiling points are absolutely different.The difference of their boiling point can be considered to be in and form the event of hydrogen bond in the hydrone.And the insulating paper material is generally cellulose, has many hydroxyls and (OH), so oxygen is the very strong atom of a kind of electronics feminine gender, has the attraction ability of electronics in the contiguous atom of combination.Therefore, by the electronics that attracts hydrogen, oxygen self is polarized to negative, and hydrogen polarization is for just.Hydrogen atom and oxygen atom are near each other, attract each other between the OH base, form hydrogen bond physically.As from the boiling point difference of water and methane as seen, hydrogen bond influences hot property to a great extent.Can expect, be that the insulating paper of material also kindred circumstances may take place with the cellulose with many hydroxyls.That is, can expect that insulating paper is near near 100 ℃ the time, by the intervention of hydrogen bond, variation has also taken place in the mechanism of its deterioration.
In view of the above, can understand:, its result is inserted to the evaluation method below 110 ℃ of electrical equipment operating temperature, its levels of precision existing problems outward according to the result of the activated deterioration test under in the past the high temperature as mentioned above.
Carry out in the activated deterioration test under the high temperature about 100-200 ℃ in the past, obtaining its test data needs the time of several months, so, then need the time more than 10 years if carrying out deterioration test under the low temperature till to 60 ℃ near the operating temperature of oil immersion electrical equipment.Time taking test like this may not be desirable from practical standpoint.Yet the data of low temperature degradation phenomena are as different with the data extrapolation value of high temperature deterioration test, and be correct just not talkative electrical equipment useful life of determining according to its result.Therefore, for improving definite accuracy in useful life, also be necessary to carry out described time-consuming permanent low temperature deterioration test.
The invention summary
The present invention system is that purpose is done with the evaluation method of the high insulating paper performance degradation of exploitation accuracy.The present inventor finds that insulating paper has special nature as described below: insulating paper is being lower than under about 110 ℃ low temperature, and is difficult like deterioration; Then its deterioration is quickened when being higher than this temperature, thus, has finished the present invention.That is, the present invention relates to a kind of evaluation method of insulating paper insulation property deterioration, described method is according to the characteristic of the physics of deterioration under the temperature of kraft pulp insulating paper in insulating oil, below 110 ℃ and/or chemistry, carries out the deterioration evaluation of this insulating paper.
As of the present invention one preferably the feature of mode be: above-mentioned physics and/or chemical characteristic are the degree of polymerization and the decomposition rate of insulating paper.
Feature as alternate manner of the present invention is: the degree of polymerization that the aforementioned degree of polymerization is represented in 1925≤A≤1930,3.6≤B≤3.7 scopes, with following formula:
D=D
0×10
-N×10{-A/(273+t)+B}
Here, D represents the degree of polymerization of insulating paper, D
0The initial polymerization degree of expression insulating paper; N represents a heating year number (year), t represent heating-up temperature (℃).
Feature as alternate manner of the present invention is: the decomposition rate that aforementioned decomposition rate is represented in 15.8≤α≤14.6,10500≤β≤10700 scopes, with following formula:
X=αexp(-β/RT)
Here, X represents (CO
2+ CO) generation speed (ml/gh); R is 1.987cal/moldeg; T represents absolute temperature (K).
Feature as alternate manner of the present invention is: the described degree of polymerization arrives the branch degree of polymerization that time of 450 represents in 0.7≤X≤1.7,8200≤Y≤8800 scopes, with following formula:
θ=Xexp(-Y/RT)
Here, θ represents that the degree of polymerization arrives for 450 time (h), and R is 1.987cal/moldeg; T represents absolute temperature (K).
The simple declaration of accompanying drawing
Figure 1 shows that according to the degree of polymerization of embodiments of the invention 1, insulating paper and the graph of a relation between the heating year number.
Figure 2 shows that according to embodiments of the invention 1, (CO
2+ speed dependent takes place in the graph of a relation of temperature CO).
Figure 3 shows that the degree of polymerization according to embodiments of the invention 1, insulating paper reach respectively 600,550,500,450 and 400 o'clock time-dependent in the graph of a relation of temperature.
Detailed Description Of The Invention
The insulating paper that the present invention uses is with the insulating paper of cellulose as material. Cellulose is that glucose combines β The Polysaccharides of-Isosorbide-5-Nitrae sugar alcohol (グ リ コ キ シ De) is with (C6H
10O
5)
nExpression. The so-called degree of polymerization means the number of n, Can determine according to the viscosimetric analysis of its cupri ethylene diamine lysate.
In insulating oil, when heating insulating paper with certain temperature, this insulating paper namely decomposes, its degree of polymerization Reduce. The relation curve that be made under each uniform temperature, heat time heating time of insulating paper and the degree of polymerization changes, root According to the mathematical expression that is derived by resulting chart, can estimate the degradation of insulating paper.
Because decomposition of cellulose generation carbon dioxide and CO gas, record under certain heating-up temperature again,, CO in the unit interval2And the growing amount of CO gas, calculate (CO2+ CO) generation speed. Connect The relation curve that be made under each heating-up temperature, gasification speed changes. According to by resulting figure Show the mathematical expression of derivation, can estimate the degradation of insulating paper.
Below, by embodiment, illustrate in greater detail the present invention.
Embodiment 1
The insulating paper that is applied to the oil immersion electrical apparatus insulation is kraft pulp system normally.The low temperature deterioration test is with the kraft pulp system insulating paper of the intensive drying (degree of polymerization: 1000) put into the insulating oil back sealing of sloughing gas, heat in the stove of 60 ℃, 80 ℃, 95 ℃ and 110 ℃.For preparing a plurality of hermetically sealed cans in each stove, hermetically sealed can takes out after doing suitably to heat the several years in stove.Measure the degree of polymerization of insulating paper and carry out the gas analysis (overview of dissolved gas analysis is narrated) of carbon dioxide and CO (carbon monoxide converter) gas in the oil in the explanation of following Fig. 2.The carrying out that test under the temperature of 60 ℃, 80 ℃ and 90 ℃ is the longest 12 years, investigate the relation of its degree of polymerization and heating years several.It the results are shown in Fig. 1.Can understand that from Fig. 1 along with the increase of heating time, the degree of polymerization of insulating paper reduces; And heating-up temperature is high more, and the decline of the insulating paper degree of polymerization is fast more.The result of Fig. 1 can following formula (1) expression.
D=D
0×10
-N×10{-A/(273+t)+B}
1925≤A≤1930、3.6≤B≤3.7
Here, D represents the degree of polymerization of insulating paper; D
0The initial polymerization degree of expression insulating paper; N represents heating year number (year); T represent heating-up temperature (℃).
After the insulating paper heating and decomposition, generate carbon dioxide (CO
2) and CO (carbon monoxide converter) gas (CO), these gas dissolvings are in insulating oil.Dissolved gas in can extracting fuel-displaced is done gas analysis with gas chromatography.
The CO that the generation speed of above-mentioned gas took place with every 1g insulating paper in 1 hour
2And the mist scale of CO shows.In other words, generation speed is relevant with the decomposition rate of insulating paper, so the molten gas flow of depositing has correlation in the degradation of insulating paper and the oil.The degradation of insulating paper can be inferred from this relation.
Fig. 2 shows (CO
2+ CO) generation speed is to dependence on temperature.Its result represents with following formula (2).
X=αexp(-β/RT)
15.8≤α≤14.6、10500≤β≤10700
Here, X represents (CO
2+ CO) generation speed (ml/gh), R is 1.987cal/moldeg; T represents absolute temperature (K).
For determining whether with low temperature deterioration test data and high temperature deterioration test data representation on same chart, also to have carried out the high temperature deterioration test in the lump.
For carrying out high temperature deterioration test as the deterioration of insulating paper evaluation method, making is as same hermetically sealed can sample used in the low temperature deterioration test, these hermetically sealed cans are heated the relation between the research insulating paper degree of polymerization and the heating year number in the stove of 130 ℃, 150 ℃ and 180 ℃.Reaching 500 o'clock time for the degree of polymerization, is that high temperature deterioration test data and low temperature deterioration test data are made a chart, shows that in Fig. 3 it is to dependence on temperature.
As for the low temperature deterioration test, except the degree of polymerization reached time of 500 o'clock, its degree of polymerization reached 400,450,550,600 o'clock time and the dependence of temperature also is shown in Fig. 3 in the lump.Wherein the degree of polymerization reaches 450 o'clock time usefulness following formula (3) expression.
θ=Xexp(-Y/RT)
0.7≤X≤1.7、8200≤Y≤8800
Here, θ represents that the degree of polymerization arrives for 450 time (h); R is 1.987Cal/moldeg; T is absolute temperature (K).Can understand that from Fig. 3 there is not the extrapolation to high temperature one side in the low temperature one side straight line of Arrhenius curve chart, but locate complications being about 110 ℃.The slope of this straight line low temperature one side is steady than its high temperature one side.This demonstration: the at high temperature easy deterioration of insulating paper is difficult for deterioration at low temperatures.
Therefore, be appreciated that as described above the influence of hydrogen bond also has influence on the deterioration of insulating paper.That is, the result of Fig. 3 shows, with the operating temperature of high temperature deterioration test data extrapolation to oil immersion electrical equipment, can not infer the degree of deterioration of insulating paper.
Thus, Fig. 1, Fig. 2 and the Fig. 3 from the low temperature deterioration test can understand: accuracy that can be very high is inferred the degradation that is in the insulating paper under the oil immersion electrical equipment operating temperature.
Again, self-evident, (1) formula also can be used the evaluation form of exponential function, and perhaps, (2) formula and (3) formula can be represented with the evaluation form of common logarithm.
In addition, in recent years, also in research by the furfural that insulating paper decompose to generate, estimate the deterioration of insulating paper degree methods, but since its degradation influence each other with the degree of polymerization, so in the method, the consideration of low temperature deterioration evaluation method is still indispensable.
In the past, with the operating temperature of about 100～200 ℃ high temperature deterioration test data extrapolation, carried out the deduction of deterioration of insulating paper degree by this to oil immersion electrical equipment.The present invention illustrates first: insulating paper is by the low temperature deterioration test of high temperature deterioration test and 12 years, and its degradation phenomena that is heated is boundary and difference with about 110 ℃; Therefore, it is very poor using the deduction accuracy of deduction method deterioration of insulating paper degree in the past.
In sum, by using the low temperature deterioration test data in the operating temperature field of oil immersion electrical equipment of the present invention, can carry out the deteriorate performance evaluation of pinpoint accuracy to insulating paper.The present invention is big in industrial meaning.
Claims (5)
1. the evaluation method of an insulating paper performance degradation is characterized in that, is index with physics and/or the chemical characteristic that deterioration takes place under the temperature of kraft pulp insulating paper in insulating oil, below 110 ℃.
2. the evaluation method of insulating paper performance degradation as claimed in claim 1 is characterized in that, above-mentioned physics and/or chemical characteristic are expressed as the degree of polymerization and the decomposition rate of insulating paper.
3. the evaluation method of insulating paper performance degradation as claimed in claim 2 is characterized in that, the degree of polymerization that the described degree of polymerization is represented in 1925≤A≤1930,3.6≤B≤3.7 scopes, with following formula:
D=D
o* 10
-N * 10{-A/ (273+t)+B}Here, D represents the degree of polymerization of insulating paper; D
0The initial polymerization degree of expression insulating paper; N represents a heating year number (year), t represent heating-up temperature (℃).
4. the evaluation method of insulating paper performance degradation as claimed in claim 2 is characterized in that, the decomposition rate that described decomposition rate is represented in 15.8≤α≤14.6,10500≤β≤10700 scopes, with following formula:
(β/RT) here, X represents (CO to X=α exp
2+ CO) generation speed (ml/gh); R is 1.987cal/moldeg; T represents absolute temperature (K).
5. as the evaluation method of claim 2 and 3 described insulating paper performance degradations, it is characterized in that, the aforementioned degree of polymerization arrive time of 450 o'clock in 0.7≤X≤1.7,8200≤Y≤8800 scopes, below state bounds evaluation and represent:
θ=Xexp(-Y/RT)
Here, θ represents that the degree of polymerization arrives for 450 time (h); R is 1.987cal/moldeg, and T represents absolute temperature (K).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB971969701A CN1161799C (en) | 1997-06-03 | 1997-06-03 | Method for evaluating deterioration of insulating paper |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB971969701A CN1161799C (en) | 1997-06-03 | 1997-06-03 | Method for evaluating deterioration of insulating paper |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1226994A true CN1226994A (en) | 1999-08-25 |
| CN1161799C CN1161799C (en) | 2004-08-11 |
Family
ID=5179768
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB971969701A Expired - Lifetime CN1161799C (en) | 1997-06-03 | 1997-06-03 | Method for evaluating deterioration of insulating paper |
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| Country | Link |
|---|---|
| CN (1) | CN1161799C (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101762680A (en) * | 2008-12-24 | 2010-06-30 | 上海宝钢工业检测公司 | Method for detecting oil service lift of large-scale transformer |
| CN104081184A (en) * | 2011-11-23 | 2014-10-01 | 特英普科技股份责任有限公司 | Device and method for assessing the degradation of the insulation of an oil-insulated transformer |
| CN105866390A (en) * | 2016-06-21 | 2016-08-17 | 林光琴 | Evaluation method for insulating properties of power transformer |
| CN107390258A (en) * | 2017-09-12 | 2017-11-24 | 广东电网有限责任公司电力科学研究院 | The confirmation method of point of discharge on a kind of insulating paper |
-
1997
- 1997-06-03 CN CNB971969701A patent/CN1161799C/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101762680A (en) * | 2008-12-24 | 2010-06-30 | 上海宝钢工业检测公司 | Method for detecting oil service lift of large-scale transformer |
| CN104081184A (en) * | 2011-11-23 | 2014-10-01 | 特英普科技股份责任有限公司 | Device and method for assessing the degradation of the insulation of an oil-insulated transformer |
| CN105866390A (en) * | 2016-06-21 | 2016-08-17 | 林光琴 | Evaluation method for insulating properties of power transformer |
| CN105866390B (en) * | 2016-06-21 | 2017-12-29 | 江苏惠聪科技有限公司 | Electric power transformer insulated method of evaluating performance |
| CN107390258A (en) * | 2017-09-12 | 2017-11-24 | 广东电网有限责任公司电力科学研究院 | The confirmation method of point of discharge on a kind of insulating paper |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1161799C (en) | 2004-08-11 |
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