On the frequency domain dielectric response of oil-paper insulation at low temperatures

Fofana, I.; Hemmatjou, H.; Meghnefi, F.; Farzaneh, M.; Setayeshmehr, A.; Borsi, H.; Gockenbach, E.

doi:10.1109/tdei.2010.5492253

Cited by 120 publications

(88 citation statements)

References 11 publications

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“…Therefore, we adopt the maximum time constant (τmax1) and the second maximum time constant (τmax2) of the extended Currently, how to quantize the ageing effect and water effect of cellulose insulation (especially the ageing effect) on PDC characteristics has become a research hotspot for experts and scholars. The authors in [22,23] proposed a system pole technique to obtain the water content in transformer cellulose insulation. The system pole can be written as:…”

Section: Large Time Constant Techniquementioning

confidence: 99%

“…The research in [22,23] has found that since the terms ρ, ε 0 and ε r have nothing to do with the insulation size, therefore the system pole P is not affected by the size of the cellulose insulation. In addition, the authors also found that the system pole P has a good correlation with the water content and ageing condition in cellulose insulation.…”

Section: Large Time Constant Techniquementioning

confidence: 99%

“…So far, many of the research findings in relation to PDC behavior have been commonly reported for diagnosing water content and ageing condition in transformer cellulose insulation [16][17][18]. However, it is somewhat difficult for power utilities to reliably and accurately predict the water content and ageing condition using the PDC technique due to the different insulation size and geometry in transformers [22][23][24][25]. Fofana et al [22] and Hadjadj et al [23] investigated whether the poles could be utilized for predicting the ageing condition of the whole transformer insulation.…”

Section: Introductionmentioning

confidence: 99%

“…However, it is somewhat difficult for power utilities to reliably and accurately predict the water content and ageing condition using the PDC technique due to the different insulation size and geometry in transformers [22][23][24][25]. Fofana et al [22] and Hadjadj et al [23] investigated whether the poles could be utilized for predicting the ageing condition of the whole transformer insulation. This new idea represented a major contribution because the poles are geometry independent.…”

Section: Introductionmentioning

confidence: 99%

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Study on Quantitative Correlations between the Ageing Condition of Transformer Cellulose Insulation and the Large Time Constant Obtained from the Extended Debye Model

et al. 2017

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Polarization-depolarization current (PDC) measurements are now being used as a diagnosis tool to predict the ageing condition of transformer oil-paper insulation. Unfortunately, it is somewhat difficult to obtain the ageing condition of transformer cellulose insulation using the PDC technique due to the variation in transformer insulation geometry. In this literature, to quantify the ageing condition of transformer cellulose insulation using the PDC technique, we firstly designed a series of experiments under controlled laboratory conditions, and then obtained the branch parameters of an extended Debye model using the technique of curve fitting the PDC data. Finally, the ageing effect and water effect on the parameters of large time constant branches were systematically investigated. In the present paper, it is observed that there is a good exponential correlation between large time constants and degree of polymerization (DP). Therefore, the authors believe that the large time constants may be regard as a sensitive ageing indicator and the nice correlations might be utilized for the quantitative assessment of ageing condition in transformer cellulose insulation in the future due to the geometry independence of large time constants. In addition, it is found that the water in cellulose pressboards has a predominant effect on large time constants.

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Section: Large Time Constant Techniquementioning

confidence: 99%

Section: Large Time Constant Techniquementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Study on Quantitative Correlations between the Ageing Condition of Transformer Cellulose Insulation and the Large Time Constant Obtained from the Extended Debye Model

et al. 2017

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“…Various methods have been developed to help to evaluate the condition of the insulating paper, including the breakdown voltage, the tensile strength, the degree of polymerization and Karl Fischer coulometric titration [9,10]. More recently, Frequency Domain Spectroscopy (FDS) [11][12][13], Polarization and Depolarization Current (PDC) [14][15][16] and Recovery Voltage Measurement (RVM) [17], which are based on dielectric response, have become a hotspot for scholars to study because of easy operation and no need for sampling. Compared with PDC and RVM, FDS has the advantages of rich insulation information and strong anti-interference ability, so it has great potential in oil-paper insulation condition evaluation [18].…”

Section: Introductionmentioning

confidence: 99%

A New Method for Evaluating Moisture Content and Aging Degree of Transformer Oil-Paper Insulation Based on Frequency Domain Spectroscopy

Xia

Gao

et al. 2017

Energies

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Abstract:The condition of oil-paper insulation is closely related to the life expectancy of a transformer. The accurate results of oil-paper have not been obtained due to the impact of influencing factors. Therefore, in order to improve the evaluation accuracy of oil-paper insulation, in this paper, oil-paper samples which were prepared with different aging and moisture content were analyzed by frequency domain spectroscopy (FDS). Results show that when the moisture content is less than 2%, the range of 10 1~1 0 3 Hz is mainly affected by moisture and aging has little effect. However, with the increase of moisture content, the effect of aging degree on this band became increasingly prominent. S m , which represents the integral value from 10 −1 to 10 −3 Hz, and S DP , which represents the integral value from 10 1 to 10 3 Hz, were extracted as characteristic parameters of moisture content and aging degree respectively. Compensation factors γ which represents the influence ratio of moisture on S DP and φ which represents the influence ratio of aging on S m were introduced to compensate for the influence of moisture content and aging degree on characteristics respectively. Then, a new method was proposed to evaluate the condition of oil-paper based on compensation factors. Through this method, the influence in characteristics can be eliminated by the obtained actual compensation factors, thus distinguishing the internal influence between moisture content and aging degree on FDS. Finally, this method was verified by field test.

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Investigation of characteristic parameters for condition evaluation of transformer oil-paper insulation using frequency domain spectroscopy

Wang

Gao

Liao

et al. 2014

Int. Trans. Electr. Energ. Syst.

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SUMMARYFrequency domain spectroscopy (FDS) is employed to evaluate the moisture content and aging state of oil-paper insulation in power transformers. Oil-paper insulation samples with different moisture content and aging states were primarily prepared in the laboratory. A method was proposed based on a study of the influence of the aging state and moisture content on the frequency domain dielectric property of oil-paper insulation. This method distinguishes the influence of moisture content and aging state on FDS through the imaginary part of complex relative permittivity (ε r ″). Relevant characteristic parameters that characterize the moisture content and aging state of oil-impregnated pressboards were also extracted. Results reveal that the extracted characteristic parameters are sensitive to moisture content in the range of 10 À1 Hz to 10 1 Hz and in the range of 10 À3 Hz to 10 À1 Hz for the aging state. An obvious exponential relationship exists between the maximum values of the characteristic parameters in the given frequency ranges and degree of polymerization and moisture content. The new method can be utilized for a non-destructive condition assessment of oil-paper insulation of transformers.

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On the frequency domain dielectric response of oil-paper insulation at low temperatures

Cited by 120 publications

References 11 publications

Study on Quantitative Correlations between the Ageing Condition of Transformer Cellulose Insulation and the Large Time Constant Obtained from the Extended Debye Model

Study on Quantitative Correlations between the Ageing Condition of Transformer Cellulose Insulation and the Large Time Constant Obtained from the Extended Debye Model

A New Method for Evaluating Moisture Content and Aging Degree of Transformer Oil-Paper Insulation Based on Frequency Domain Spectroscopy

Investigation of characteristic parameters for condition evaluation of transformer oil-paper insulation using frequency domain spectroscopy

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