On the Estimation of Elapsed Life of Oil-Immersed Power Transformers

Pradhan, Manoj Kumar; Ramu, T.S.

doi:10.1109/tpwrd.2005.848663

Cited by 104 publications

(35 citation statements)

References 15 publications

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“…Therefore other measure has to be used to estimate the degradation of dielectric paper, for instance the concentration of furanic compounds. There are different authors [11,[15][16][17][18] who developed equations which relate one or more properties of the insulating system and the life expectancy of the transformer, Tables IV. This expectancy is based on the aging of the insulation paper.…”

Section: Estimation Of Transformer's Life Expectancy Through Mathematmentioning

confidence: 99%

“…In order to evaluate the suitability of some of these equations, it was estimated firstly the DP using the mathematical expressions proposed by [6][7][8][9][10][11][12][13][14]. Secondly, using the equations from [11,[15][16][17][18], the lifetime of the transformer based on paper aging was obtained. This methodology was applied to all the transformer that were studied in this work.…”

Section: Estimation Of Transformer's Life Expectancy Through Mathematmentioning

confidence: 99%

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Estimating the age of power transformers using the concentration of furans in dielectric oil

Fernández¹,

Fernández²,

Santisteban³

et al. 2016

REPQJ

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Abstract.Transformers have an insulation system based on dielectric oil and paper. Several factors as shortcircuits, high load, or overheating influence the aging of the insulating system. Thus, these materials are decomposed during transformer operation, and its state determines the status of the transformer. The degree of polymerization of dielectric paper is an indicator of its real condition. The concentration of furanic compounds in oil offer an estimation of paper degradation. Moreover, these compounds are easy to measure from oil samples. This paper review equations which relate one or more properties of the insulating system with the life expectancy of the transformer. These equations were used in a fleet of transformers in order to estimate the accuracy of these mathematical models. Results show that these methods achieve the most reliable estimation when the transformers have operated less than 8 years. Nevertheless, when the transformers are older, the estimation of lifetime based on furanic compounds is quite erratic and should be improved.

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Section: Estimation Of Transformer's Life Expectancy Through Mathematmentioning

confidence: 99%

Section: Estimation Of Transformer's Life Expectancy Through Mathematmentioning

confidence: 99%

Estimating the age of power transformers using the concentration of furans in dielectric oil

Fernández¹,

Fernández²,

Santisteban³

et al. 2016

REPQJ

View full text Add to dashboard Cite

show abstract

“…In the transformer oil paper insulation system, the moisture absorption ability of insulation paper is approximately 10 4 times stronger than that of insulating oil, and the vast majority of moisture exists in the insulation paper when the moisture is in balance in the oil-paper insulation system [16]. For condenser bushing, the thickness of insulation paper is thinner than that of insulation paper in transformers and the moisture absorption ability is stronger, so the moisture is almost completely concentrated in the insulation paper, accelerating the insulation aging.…”

Section: Change Trend Of the Moisture Content In Insulating Papermentioning

confidence: 99%

Study of the Impact of Initial Moisture Content in Oil Impregnated Insulation Paper on Thermal Aging Rate of Condenser Bushing

et al. 2015

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This paper studied the impact of moisture on the correlated characteristics of the condenser bushings oil-paper insulation system. The oil-impregnated paper samples underwent accelerated thermal aging at 130˝C after preparation at different initial moisture contents (1%, 3%, 5% and 7%). All the samples were extracted periodically for the measurement of the moisture content, the degree of polymerization (DP) and frequency domain dielectric spectroscopy (FDS). Next, the measurement results of samples were compared to the related research results of transformer oil-paper insulation, offering a theoretical basis of the parameter analysis. The obtained results show that the moisture fluctuation amplitude can reflect the different initial moisture contents of insulating paper and the mass ratio of oil and paper has little impact on the moisture content fluctuation pattern in oil-paper but has a great impact on moisture fluctuation amplitude; reduction of DP presents an accelerating trend with the increase of initial moisture content, and the aging rate of test samples is higher under low moisture content but lower under high moisture content compared to the insulation paper in transformers. Two obvious "deceleration zones" appeared in the dielectric spectrum with the decrease of frequency, and not only does the integral value of dielectric dissipation factor (tan δ) reflect the aging degree, but it reflects the moisture content in solid insulation. These types of research in this paper can be applied to evaluate the condition of humidified insulation and the aging state of solid insulation for condenser bushings.

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“…Also, the incremental time duration of these blocks is adjusted such that the amount of aging during each block remains nearly the same, in accordance with the norms of equated aging procedure. Throughout the experimental run, the electrical stress was kept at normal levels (i.e., transformers were operated at rated voltage) (Pradhan 2004(Pradhan , 2006(Pradhan , 2005. …”

Section: A Prototype Modelmentioning

confidence: 99%

Review of Different Prorated Models Which Detects the Effect of Accelerated Stresses on Power Transformer Insulation

Singh¹,

Sood²,

Verma³

2010

IJCEE

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Abstract--Transformer protection and safety is based on large number of tests. On the basis of these test results, vital decision on transformer diagnostic and condition monitoring is done. But some times it is not possible to conduct the tests on transformer in service because it may destructive in nature so, in order to perform these tests, scaled-down or prorated models of actual power transformers are used in experimental study. In this paper, different prorated models with their aging cycles have been studied.

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On the Estimation of Elapsed Life of Oil-Immersed Power Transformers

Cited by 104 publications

References 15 publications

Estimating the age of power transformers using the concentration of furans in dielectric oil

Estimating the age of power transformers using the concentration of furans in dielectric oil

Study of the Impact of Initial Moisture Content in Oil Impregnated Insulation Paper on Thermal Aging Rate of Condenser Bushing

Review of Different Prorated Models Which Detects the Effect of Accelerated Stresses on Power Transformer Insulation

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