Assessment of power transformer insulation condition

Соколов, В. В.; Bulgakova, V.; Berler, Z.

doi:10.1109/eeic.2001.965766

Cited by 6 publications

(4 citation statements)

References 1 publication

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“…The water released from paper insulation, which is in electric field, can lead to dangerous partial discharges [15] and also to dangerous pressure increase in the transformer's tank. High pressure in the tank can cause pressing the oil out through the silica gel breather or any leaks [16].…”

Section: Bubble Effectmentioning

confidence: 99%

The influence of cellulose insulation aging degree on its water sorption properties and bubble evolution

Przybyłek

2010

IEEE Trans. Dielect. Electr. Insul.

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The paper concerns the issue of water in a oil-paper insulating system of a transformer. The author described the influence of Kraft paper ageing on its water sorption and desorption properties. The research was done for new and substantially aged paper. The paper ageing degree was described by means of the cellulose polymerization degree. Volume absorption and line sorption of new and aged paper were investigated. The research was done taking into consideration moisture distribution in the transformer's insulating system and possibilities to generate a particular kind of water desorption called the bubble effect. The article discusses this effect, which is dangerous for the transformer. The author refers to factors which affect the initiation temperature of the bubble effect. Moreover, the article presents research results of the bubble effect initiation temperature for new and aged paper as a function of water content in paper insulation. Formulae describing the initiation temperature of the bubble effect are given for some assumed conditions.

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Section: Bubble Effectmentioning

confidence: 99%

The influence of cellulose insulation aging degree on its water sorption properties and bubble evolution

Przybyłek

2010

IEEE Trans. Dielect. Electr. Insul.

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“…Reações de hidrólise que ocorrem no interior dos equipamentos por ação de metais, também produzem este gás (Pugh, 1973). Alguns tipos de metais utilizados na constituição de equipamentos possuem em seu interior hidrogênio em função de seu processo de fabricação (Sokolov et al,2001).…”

Section: Alguns Fatores Que Geram Incertezas Na Análise De Gasesunclassified

“…Este fenômeno depende da temperatura do meio e pode levar à determinação de concentrações de gases bastante diferentes (Kan e Miyamoto, 1995). Um exemplo desta variação é apresentado na Tabela 1 (Sokolov et al,2001), onde para um mesmo transformador é feita a amostragem dos gases dissolvidos no óleo em duas temperaturas diferentes.…”

Section: Alguns Fatores Que Geram Incertezas Na Análise De Gasesunclassified

Metodologias para avaliação e diagnóstico do estado de isolamentos de papel impregnado com óleo mineral

Zirbes

Rolim

Zurn

2005

Sba Controle & Automação

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O isolamento elétrico mais comumente utilizado em subestações de média, alta ou extra alta tensão é o de celulose impregnada com óleo mineral isolante, em função de sua eficácia e custo reduzido. Sua utilização abrange transformadores de potência e suas buchas, reatores e transformadores de medição de corrente e tensão. Este artigo discute as metodologias tradicionais utilizadas na análise de estado e no diagnóstico do isolamento a partir do fator de dissipação e da concentração de gases dissolvidos no óleo, considerando os principais fatores que afetam estes valores. São também abordados alguns aspectos que causam incerteza na medição e nas metodologias de análise. É apresentada a modelagem de uma rede neural artificial para diagnóstico e identificação de estado do isolamento a partir de dados de concentração de gases dissolvidos no óleo, sendo os resultados obtidos comparados com os das metodologias tradicionais baseadas em normas.
Cellulose impregnated with mineral oil is the most used insulating material in medium, high or extra high voltage substations, due to its efficacy and low cost. This material is employed in power transformers and its bushings, reactors, capacitors and measurement voltage and current transformers. This paper discusses the methodologies traditionally used to assess the insulating state of impregnated paper and to diagnose faults through the dissipation factor and the concentration of gases dissolved in the oil, regarding some factors that may affect those variables. Uncertainties in measured parameters and analysis methods are also considered. Some results obtained with the application of traditional methodologies (standards) for incipient fault detection based on gas analysis are compared with results obtained from the application of a artificial neural network proposed for this task

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“…For many decades, identifying technique of PD source has been the critical issue in insulation diagnosis of large power transformer [1]. Extensive experiments have introduced PD locating techniques by integration process of signals from AE sensors installed on power transformer tank wall [2], [3].…”

Section: Introductionmentioning

confidence: 99%

A proposal for Hybrid PD sensor identifying absolute distance from PD source

Kim

Hikita

2013

2013 Annual Report Conference on Electrical Insulation and Dielectric Phenomena

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In this paper, the authors proposed a Hybrid PD (AE) sensor which could tell us an absolute distance from PD source. The proposed sensor installed at one fixed position of power transformer tank wall could detect HF signal and ultrasonic one simultaneously. Ignoring faster arrival time of HF signal, an approximated absolute distance from PD source could be derived easily. Moreover, applying time series measurement to the scheme, a pair of PD signals could enable us to discriminate true PD signals from noise spectra. This paper also shows the laboratory experimental results from an oil transformer of 6 kV.

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Assessment of power transformer insulation condition

Cited by 6 publications

References 1 publication

The influence of cellulose insulation aging degree on its water sorption properties and bubble evolution

The influence of cellulose insulation aging degree on its water sorption properties and bubble evolution

Metodologias para avaliação e diagnóstico do estado de isolamentos de papel impregnado com óleo mineral

A proposal for Hybrid PD sensor identifying absolute distance from PD source

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