Dielectric Properties of Natural Esters and their Influence on Transformer Insulation System Design and Performance

Prevost, Thomas

doi:10.1109/tdc.2006.1668448

Cited by 43 publications

(22 citation statements)

References 2 publications

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“…Table 3 shows the relative permittivity and dielectric dissipation factor at different temperature. The relative permitivitty and dielectric dissipation factor are sensitive to temperature changing [25]. For pressboards impregnated under mineral oil, the relative permittivity (capacitance) value increases with the increasing temperature.…”

Section: B Pd and Pdiv Measurement Results Partial Discharge Inceptimentioning

confidence: 99%

Considerations for Dielectric Properties Measurements of Oil Immersed Pressboard

Pratomosiwi¹,

Pattanadech²,

Wieser³

et al. 2012

ijeei

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Dielectric properties including relative permittivity, dielectric dissipation factor (DDF) and dc resistivity has been used widely as a design parameter of insulation system. In measuring dielectric properties of oil immersed material (OIM), we have to make some adaptations from IEC 60093 and IEC 60250.This paper is focused on dielectric properties measurement of oil immersed pressboard (OIP) i.e. related to the effect of live electrode corner shape, the effect of electrode's weight, and the applied the electric field stress and temperature.In this experiment, the solid and liquid dielectric wereoil immersed transformer board type B 3.1A and operated under mineral oil bath, Nynas Nytro 4000x. We concluded that, round-cornered electrode yields steep electric field enhancement at the oil side. This phenomena makes it easier to generate oil discharge in the wedgewhen compared to sharp-cornered electrode. For measuring dielectric properties at high voltage level, this phenomenon should take into account. It was also found that electrode with pressure higher than 1.9 N/cm2 gives enough pressure to prevent a thin oil layer that present on surface.We also notice that for small g h ⁄ ratio (the gap of guard and guarded electrode is small compared to the sample) or thick sample, the fringing effect is high. Therefore calculation of effective area according to IEC 60093 is considerably applicable for thick sample. These results could be used as a consideration when measuring dielectric properties of oil immersed pressboardin compliment with IEC 60093 and IEC 60250.

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Section: B Pd and Pdiv Measurement Results Partial Discharge Inceptimentioning

confidence: 99%

Considerations for Dielectric Properties Measurements of Oil Immersed Pressboard

Pratomosiwi¹,

Pattanadech²,

Wieser³

et al. 2012

ijeei

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“…K.J. Rapp et al [27] in June 2005 and T.A.Prevost, in May 2006 [28] explained lower degradation rate of paper is due to higher affinity of esters to water due to which water shifts to esters and keeps the paper dry which reduces the aging and increases the life time of paper. D. Martin et al [29] in July 2007, described AC impulse with stand voltage for insulation paper impregnated in esters is more than insulation paper impregnated in mineral oil.…”

Section: Insulation Paper Studiesmentioning

confidence: 99%

Review on ester based dielectric liquids for transformer insulation technology

Rao

Sood

Jarial

2015

2015 International Conference on Condition Assessment Techniques in Electrical Systems (CATCON)

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Ester based dielectric fluids were found to beat mineral oils in thermal and environmental aspects. Hence there is a great need of research on ester oils. The present paper is a review of 84 published articles. Owing to length of the document; exceptions were made to include a citation if a publication contributed a significantly technical viewpoint on usage of ester oils for transformer insulation technology. The selected literature has been classified into relevant sections to make researchers convenient in obtaining literature. Some citations spanned for more than one section, efforts were made to include such citations in one of the most relevant section. The present paper will be useful to the industry and researchers to know the significance and need of ester based dielectrics to the present day scenario.

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“…Table I shows the temperature rise significantly increases the DC conductivity of the test object. The possibility that natural ester-based oils generate more amounts of gases when subject to thermal overstress may cause the significant discrepancy in the conductivity of mineral and biodegradable oil [9][10][11][12]. Also, the hydrophilic nature of the biodegradable oil as well as its chemical makeup which makes it have more polar character can give a rise to the test object conductivity [5,13,14].…”

Section: B Effect Of Tempraturementioning

confidence: 99%

Dielectric response of transformer insulation oils

Shareghi

Phung

Naderi

et al. 2012

2012 10th International Power &Amp; Energy Conference (IPEC)

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Dielectric diagnosis with polarization and depolarization currents (PDC) which employs the dielectric response of system in time domain is applied to investigate differences between PDC patterns produced by two types of transformer insulating fluids, mineral and bio-degradable oil. The mineral oil used is Shell Diala BX, and the biodegradable one is Envirotemp FR3. The latter is ester-based, and a relatively new transformer insulating fluid introduced as an environmentally-friendly alternative to conventional mineral oil. The DC conductivity of the two oil types is obtained under the effects of various temperature and moisture levels. The experiment is conducted for two levels of moisture when temperature factor is changed from ambient to 90 °C. The oil water content measurement is conducted using Karl-FischerTitration. Also, an attempt was made to investigate the effects that different testing voltages and time durations have on the polarization and depolarization spectrum. A range of DC voltages up to 1000V, and time durations from 1000 to 10000 seconds have been applied. Finally, all the PDC patterns obtained under the effect of mentioned factors are evaluated.

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Dielectric Properties of Natural Esters and their Influence on Transformer Insulation System Design and Performance

Cited by 43 publications

References 2 publications

Considerations for Dielectric Properties Measurements of Oil Immersed Pressboard

Considerations for Dielectric Properties Measurements of Oil Immersed Pressboard

Review on ester based dielectric liquids for transformer insulation technology

Dielectric response of transformer insulation oils

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