Condition monitoring of transformer oil using thermal analysis and other techniques

Degeratu, Sonia; Rotaru, P.; Rizescu, Sabin; Dănoiu, Suzana; Bizdoaca, Nicu George; Alboteanu, Laurentiu; Manolea, Horia Octavian

doi:10.1007/s10973-014-4276-3

Cited by 35 publications

(14 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Traditionally, mineral oils [1] are used as the electroinsulating fluid in the transformers, a strong biodegradable petroleum derivative [2], which, although having acceptable physical and dielectric characteristics and a relatively low cost, has a number of disadvantages such as: limited thermal stability [3][4][5][6][7][8], corrosive aggressivity due to sulfur content [8][9][10][11][12][13][14][15][16][17], reduced compatibility with the cellulose from Kraft paper -furanic products formation [18][19][20][21][22], relatively low flammability (below 150 o C) and excessive flammable gases formation [30] (high risk of explosions and devastating fires), etc. To increase thermal stability and to reduce the corrosive aggressiveness of electro-insulating oils, manufacturers often use antioxidant additives and / or corrosion inhibitors [15][16][17]31].…”

mentioning

confidence: 99%

Thermooxidative Behavior of Some Paint Materials in Natural Ester Based Electro-insulating Fluid

Lungulescu¹,

Lıngvay²,

Ungureanu³

et al. 2018

Mat.Plast.

View full text Add to dashboard Cite

ATR / FTIR and DSC techniques have been used to evaluate the thermal stability of some ageing paint materials by heat treatment while immersion in natural ester-based electro-insulating oil. Experimental determinations have highlighted the fact that the investigated paint materials (epoxy resins) have a high oxygen affinity and thus, in closed systems (such as power transformers), they oxidize before coming into contact with the transformer oil. This behavior indicates that the paint layer (suitably chosen) applied on the inside of the transformer vat functions as an antioxidant and results in increasing the thermal stability of the oil.

show abstract

mentioning

confidence: 99%

Thermooxidative Behavior of Some Paint Materials in Natural Ester Based Electro-insulating Fluid

Lungulescu¹,

Lıngvay²,

Ungureanu³

et al. 2018

Mat.Plast.

View full text Add to dashboard Cite

show abstract

“…Power transformer oil undergoes continuous deterioration and degradation because of electrical, thermal, mechanical, and environmental stresses occurring during operation [4]. Therefore any deterioration in the oil can lead to premature failure of the equipment.…”

Section: Introductionmentioning

confidence: 99%

“…Megger OTS 100 AF/2 installation for breakdown testing the mineral: (a) general view, (b) testing oil tank.4.2 Ageing RateVarious physicochemical and electric properties were measured to detect changes and determine the rates of ageing of the fluids[19]: Dissipation Factor (Tan δ), Resistivity, Total acid number (TAN) and Water Content in both new and regenerated insulating fluids. The ageing rates were assessed according to the equations (1)-(4). The reference values were obtained with initial new and regenerated oils samples.…”

mentioning

confidence: 99%

Comparative study of the degradation rate of new and regenerated mineral oils following electrical stress

Oumert

Boucherit

Zafour

et al. 2018

IET Generation, Transmission & Distribution

View full text Add to dashboard Cite

The objective of this contribution was to study the behaviour of new and regenerated insulating oil used in power transformers under the influence of an electric stress. To estimate the degradation rate of the dielectric fluids, one thousand (1000) successive breakdowns were generated according to the IEC 60156 standard. The parameters such as dissipation factor (Tan ), resistivity, total acid number (TAN) and oil water Content were measured and examined following IEC/ISO standards. Good correlations have been obtained between TAN/resistivity and Tan  which might provide a "picture" of the fluid condition. The dissolved oxidation products for the two dielectric fluids (after the application of electric breakdowns), was evaluated by infrared spectroscopy (FT-IR). The results obtained indicate that the degradation of the parameters is significant and confirms the influence of an alternative electric field (AC) on the new and regenerated oils. It was also suspected that inhibitors and antioxidants were removed from the oil after regeneration. Their concentration should therefore be monitored and replenished when necessary.

show abstract

“…It should be underlined that, further to the thermooxidative ageing of the oil transformers [40][41][42][43][44][45][46] and the degradation of the electro insulating paper, highly determined by the dissolved oxygen and the humidity of the oil transformer, several toxic furfural products [47][48][49][50] and / or of flammable gases are produced [51][52][53][54][55][56][57][58] which may lead to the explosion of the oil transformer followed by devastating wildfires [55,57].…”

mentioning

confidence: 99%

Ageing of Some Painting Materials Subjected to Thermal Treatment in Natural Esters

Rus¹,

Caramitu²,

Ungureanu³

et al. 2018

Mat.Plast.

View full text Add to dashboard Cite

This paper describes the evaluation of the aging process of some polymeric painting materials subjected to a thermal treatment in electro insulating fluids, based on natural esters (vegetable oils). The paint layers surface morphology was comparatively characterized by FESEM technique, prior to the exposure, and after 1000 h of exposure to vegetable oil, heated at 130oC. The results show a substantial increase in the pulling resistances for all the painting materials subjected to this investigation, especially in the presence of the Kraft insulating paper and copper foil (inserted compulsory to emulate the actual working environment), due to an increase in the painting material adhesion, as well as an increase of the tensile strength of the paint layer. These findings may open new theoretical and practical research prospects, particularly in the field of preliminary treatments for materials used for heavy duty industrial transformers.

show abstract

Condition monitoring of transformer oil using thermal analysis and other techniques

Cited by 35 publications

References 40 publications

Thermooxidative Behavior of Some Paint Materials in Natural Ester Based Electro-insulating Fluid

Thermooxidative Behavior of Some Paint Materials in Natural Ester Based Electro-insulating Fluid

Comparative study of the degradation rate of new and regenerated mineral oils following electrical stress

Ageing of Some Painting Materials Subjected to Thermal Treatment in Natural Esters

Contact Info

Product

Resources

About