Investigation of aging degradation status of insulating elements in oil-immersed transformer and its diagnostic method based on field measurement data

Okabe, Shigemitsu; Ueta, Genyo; Tsuboi, Toshihiro

doi:10.1109/tdei.2013.6451376

Cited by 68 publications

(22 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Their reliability is significant for the safety and stability of power grids [1]. It is well known that dissolved CO and CO 2 [2,3], furans [4,5] and dielectric properties of oil [6,7] can be used for the aging evaluation of an operating transformer [8]. Under the long-term operation, mineral oil will react with dissolved oxygen to form carboxylic acids of varying molecular weight and then dissolve in transformer oil [9].…”

Section: Introductionmentioning

confidence: 99%

A Novel Method to Directly Analyze Dissolved Acetic Acid in Transformer Oil without Extraction Using Raman Spectroscopy

Wan

Chen

et al. 2017

Energies

View full text Add to dashboard Cite

Analyzing the concentration of low molecular acids dissolved in oil is vital in the oil-paper insulation aging diagnostic procedure of power transformers. The existing methods cannot distinguish between different acid types and their strengths. In this study, an improved solution Raman detection platform is fabricated. The direct measurement of dissolved acetic acid, a kind of low molecular acids, is observed in transformer oil without extraction. The Raman shift line of oil-dissolved acetic acid at 891 cm −1 corresponding to H-C-H symmetrical swing and O-H swing modes is taken as its characteristic value. Taking Raman shift line of pure oil at 932 cm −1 as an internal standard, a linear regression curve for quantitative analysis is obtained with a slope of 0.19. The best platform parameter of accumulation number is 300, which is determined by Allan deviation analysis. The current concentration detection limit and accuracy for oil-dissolved acetic acid are obtained at about 0.68 mg/mL and 91.66%, separately. The results show that Raman spectroscopy could be a useful alternative method for evaluation insulation aging state of an operating power transformer in the future.

show abstract

Section: Introductionmentioning

confidence: 99%

A Novel Method to Directly Analyze Dissolved Acetic Acid in Transformer Oil without Extraction Using Raman Spectroscopy

Wan

Chen

et al. 2017

Energies

View full text Add to dashboard Cite

show abstract

“…The permissible concentrations of furfural in oil is 1.5 mg/L at caution and 15 mg/L at danger level respectively. 6 The proposed method in this paper has ability to alarm when abnormal ageing occurs in transformer, and meet the basic requirements of engineering application. …”

Section: Resultsmentioning

confidence: 99%

“…Therefore, the evaluation of insulation ageing condition is usually achieved by detecting the content of furfural in oil. [3][4][5][6] High-performance liquid chromatography (HPLC), colorimetric method and ultraviolet (UV) spectrophotometry were traditionally used to detect furfural content in oil. However, HPLC requires professionals to perform complex operations in lab, and has elution difficulty and extra column effect.…”

Section: Introductionmentioning

confidence: 99%

Application of surface enhanced Raman scattering and competitive adaptive reweighted sampling on detecting furfural dissolved in transformer oil

et al. 2018

View full text Add to dashboard Cite

Detecting the dissolving furfural in mineral oil is an essential technical method to evaluate the ageing condition of oil-paper insulation and the degradation of mechanical properties. Compared with the traditional detection method, Raman spectroscopy is obviously convenient and timesaving in operation. This study explored the method of applying surface enhanced Raman scattering (SERS) on quantitative analysis of the furfural dissolved in oil. Oil solution with different concentration of furfural were prepared and calibrated by high-performance liquid chromatography. Confocal laser Raman spectroscopy (CLRS) and SERS technology were employed to acquire Raman spectral data. Monte Carlo cross validation (MCCV) was used to eliminate the outliers in sample set, then competitive adaptive reweighted sampling (CARS) was developed to select an optimal combination of informative variables that most reflect the chemical properties of concern. Based on selected Raman spectral features, support vector machine (SVM) combined with particle swarm algorithm (PSO) was used to set up a furfural quantitative analysis model. Finally, the generalization ability and prediction precision of the established method were verified by the samples made in lab. In summary, a new spectral method is proposed to quickly detect furfural in oil, which lays a foundation for evaluating the ageing of oil-paper insulation in oil immersed electrical equipment.

show abstract

“…The safety and stability of such transformers are both important and necessary in operating power systems [3]. Oil-paper insulation is an important form of power transformer insulation system; the remaining life of the transformer largely depends on the insulation status of oil-paper which is affected by thermal, mechanical, partial discharge and other aging factors in the long-running process [4][5][6]. Therefore, using an accurate assessment tool to evaluate the condition of oil-paper insulation has become a popular research topic.…”

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

View full text Add to dashboard Cite

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.

show abstract

Investigation of aging degradation status of insulating elements in oil-immersed transformer and its diagnostic method based on field measurement data

Cited by 68 publications

References 7 publications

A Novel Method to Directly Analyze Dissolved Acetic Acid in Transformer Oil without Extraction Using Raman Spectroscopy

A Novel Method to Directly Analyze Dissolved Acetic Acid in Transformer Oil without Extraction Using Raman Spectroscopy

Application of surface enhanced Raman scattering and competitive adaptive reweighted sampling on detecting furfural dissolved in transformer oil

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

Contact Info

Product

Resources

About