Contribution to static electrification of mineral oils and natural esters

Kolcunová, Iraida; Kurimský, Juraj; Cimbala, Roman; Petráš, Jaroslav; Dolník, Bystrík; Džmura, Jaroslav; Balogh, Jozef

doi:10.1016/j.elstat.2017.01.024

Cited by 21 publications

(7 citation statements)

References 3 publications

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“…It is observed that streaming current did not show much variation with disc velocity upto 300 rpm but at higher disc velocities (>300 rpm), a significant change in the current has been noticed. This sudden increase in the current could be associated with higher friction exerted between the fluid/pressboard [39]. With increase in the temperature, the rise in the current observed at 90°C is around six times higher than that measured at ambient temperature (30°C).…”

Section: E Electrostatic Charging Tendency (Ect) Of Punga Oilmentioning

confidence: 73%

Investigation on Impact of Magnetic Field on the Corona Discharge Activity in Punga Oil Using Fluorescent Fiber and UHF Sensor Techniques

Murugesan¹,

Amalanathan

Sarathi

et al. 2021

IEEE Access

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This paper reports the experimental investigation of the corona discharge activity of punga oil under the influence of a local magnetic field and different voltage profiles (AC and DC voltages) using fluorescent fiber sensor as well as UHF sensor technique. The corona inception voltage (CIV) of punga oil is higher under negative DC voltage followed by positive DC and AC voltage, with a marginal reduction in its CIV magnitude observed on the impact of external magnetic field. The dominant frequency of the UHF signal obtained under AC voltage shifted towards lower frequency (0.6 GHz) with the influence of magnetic flux density to about 85 mT. The rise time, pulse width and energy content of the fluorescent signal formed due to corona activity under AC voltage is found to vary under high magnetic fields confirming the inception results. The fluorescent signals formed due to corona discharge under both AC and DC voltages has its dominant frequency at 1 MHz with no shift observed in the presence of magnetic field. Also, there is no variation in the phase resolved partial discharge (PRPD) pattern observed due to corona discharge (with and without magnetic field) signal using both UHF sensor and the fluorescent sensor. The fluorescent fiber-based technique provides a better accuracy on detecting the corona discharges in punga oil at an early stage compared to conventional UHF sensor. The breakdown voltage of punga oil under different voltage profiles with and without the effect of magnetic field follows normal distribution. The dielectric dissipation factor and electrostatic charging tendency (ECT) of punga oil is observed to be higher than the limit set for insulating fluids towards power transformer operation.INDEX TERMS corona discharge, magnetic field, fluorescent fiber, UHF sensor, rise time, streaming current.

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Section: E Electrostatic Charging Tendency (Ect) Of Punga Oilmentioning

confidence: 73%

Investigation on Impact of Magnetic Field on the Corona Discharge Activity in Punga Oil Using Fluorescent Fiber and UHF Sensor Techniques

Murugesan¹,

Amalanathan

Sarathi

et al. 2021

IEEE Access

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“…An increase in the current is observed with spinning velocity due to the effect of the variation of the Debye length. This increase may also be attributed to the friction exerted between the solid and liquid insulation [30]. A positive streaming current is observed in all oil samples (Figure 13b) and it was higher for Sample C compared with Samples A and B.…”

Section: Resultsmentioning

confidence: 97%

Impact of adding activated bentonite to thermally aged ester‐based TiO₂nanofluids on insulation performance

Amalanathan

Harid

Griffiths

et al. 2021

IET Nanodielectrics

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The authors report the key findings from an experimental study that explored the use of activated bentonite for the reclamation of thermally aged ester‐based transformer nanofluids to improve their insulation performance. Bentonite activated with acid treatment caused an increase in the specific surface area and pore volume of bentonite compared to the bentonite sample before treatment, thus imparting an improved adsorption capability. Physico‐chemical diagnostic studies were carried out to characterise the activated bentonite. The insulation performance of the reclaimed natural ester and nano‐filled ester fluid samples was assessed by measuring the corona inception voltage and breakdown voltage of each fluid sample, apart form measuring the flow electrification current using the spinning disk method. The results revealed that the reclamation process improved the corona inception voltage, dissipation factor and the breakdown voltage of the base ester fluid sample due to attraction of carbon particles to activated bentonite, but no significant variation was observed with nanofluids due to the depletion of the electrical double layer. The flow electrification current of ester and ester nanofluids reduced after treatment with activated bentonite, may be attributed to the interaction between copper and bentonite that alters the double layer formation responsible for the separation of charges.

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“…The research carried out by various authors indicates a general tendency towards stronger static electrification of esters in relation to mineral oils [67,68,155]. As is shown by the research presented by Paillat et al [156], the electrification current tends to increase with the increasing ester oil rate of movement relative to the solid phase as well as the function of flow time and temperature.…”

Section: Static Electrification Of Synthetic Estersmentioning

confidence: 83%

“…As is shown by the research presented by Paillat et al [156], the electrification current tends to increase with the increasing ester oil rate of movement relative to the solid phase as well as the function of flow time and temperature. Kolcunova et al [155] explained the increase in the value of current with an increase in the speed of phase movement by the changes in the thickness of the laminar sub-layer in relation to the Debye-length. This is a general property also confirmed for mineral oil by researchers [157,158].…”

Section: Static Electrification Of Synthetic Estersmentioning

confidence: 99%

A Review on Synthetic Ester Liquids for Transformer Applications

et al. 2020

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Synthetic esters have become more and more popular in last few decades, explaining the increasing number of units filled with this liquid year by year. They have been investigated under different aspects, both from the fundamental point of view and breakdown mechanisms, well as from the application point of view. However, their use in high voltage equipment is always a challenge and deeper knowledge of the various aspects that can be encountered in their exploitation is needed. The intent of this review paper is to present the recent research progress on synthetic ester liquid in relation to the selected issues, most important for ester development in the authors’ opinion. The described issues are the breakdown performance of synthetic esters, lightning impulse strength and pre-breakdown phenomena of synthetic esters, synthetic esters-based nanofluids, combined paper-synthetic ester based insulating systems, application of synthetic ester for retro-filling and drying of mineral oil-immersed transformers, DGA(dissolved gas analysis)-based diagnosis of synthetic esters filled transformers as well as static electrification of synthetic esters. The different sections are based both on the data available in the literature, but above all on the authors’ own experience from their research work on synthetic ester liquids for electrical application purposes.

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Contribution to static electrification of mineral oils and natural esters

Cited by 21 publications

References 3 publications

Investigation on Impact of Magnetic Field on the Corona Discharge Activity in Punga Oil Using Fluorescent Fiber and UHF Sensor Techniques

Investigation on Impact of Magnetic Field on the Corona Discharge Activity in Punga Oil Using Fluorescent Fiber and UHF Sensor Techniques

Impact of adding activated bentonite to thermally aged ester‐based TiO₂nanofluids on insulation performance

A Review on Synthetic Ester Liquids for Transformer Applications

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Contribution to static electrification of mineral oils and natural esters

Cited by 21 publications

References 3 publications

Investigation on Impact of Magnetic Field on the Corona Discharge Activity in Punga Oil Using Fluorescent Fiber and UHF Sensor Techniques

Investigation on Impact of Magnetic Field on the Corona Discharge Activity in Punga Oil Using Fluorescent Fiber and UHF Sensor Techniques

Impact of adding activated bentonite to thermally aged ester‐based TiO2nanofluids on insulation performance

A Review on Synthetic Ester Liquids for Transformer Applications

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Product

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Impact of adding activated bentonite to thermally aged ester‐based TiO₂nanofluids on insulation performance