Statistical analysis of AC dielectric breakdown in transformer oil-based magnetic nanofluids

Rajňák, Michal; Kurimský, Juraj; Cimbala, Roman; Čonka, Zsolt; Bartko, Pavol; Šuga, Matej; Paulovičová, K.; Tóthová, Jana; Karpets, Maksym; Kopčanský, P.; Τimko, M.

doi:10.1016/j.molliq.2020.113243

Cited by 22 publications

(13 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, transferring high voltages leads to an increase in internal heat generation and power dissipation of the transformer [1]. The statistical report confirms that, due to poor thermophysical and dielectric properties of the transformer oil, the life span of a transformer is decreased to 17.8 years, which is practically half of its expected life (35-40 years) [2]. Thus, the stable operation and the reliability of a transformer relies mainly on the thermophysical and dielectric properties of the transformer oil used.…”

Section: Introductionmentioning

confidence: 57%

Experimental Studies on Thermophysical and Electrical Properties of Graphene–Transformer Oil Nanofluid

Almeida

Paul

Asirvatham

et al. 2020

Fluids

View full text Add to dashboard Cite

The thermophysical and electrical properties of graphene–transformer oil nanofluid at three weight percentage concentrations (0.01%, 0.03%, and 0.05%) were experimentally studied. Experiments conducted to find viscosity, surface tension, density, specific resistance, electrical conductivity, and dielectric dissipation at various temperatures ranging from 20 °C to 90 °C. It was noted that the nanofluid with 0.05% concentration showed an enhancement of 2.5% and 16.6% for density and viscosity, respectively, when compared to transformer oil. In addition, an average reduction in surface tension is noted to be 10.1% for the maximum concentration of nanofluid. Increase in heat load and concentration improves Brownian motion and decreases the cohesive force between these particles, which results in a reduction in surface tension and increases the heat-transfer rate compared to transformer oil. In addition, for the maximum concentration of nanoparticles, the electrical conductivity of nanofluid was observed to be 3.76 times higher than that of the transformer oil at 90 °C. The addition of nanoparticles in the transformer oil decreases the specific resistance and improves the electrical conductivity thereby enhancing the breakdown voltage. Moreover, the thermophysics responsible for the improvement in thermophysical and electrical properties are discussed clearly, which will be highly useful for the design of power transmission/distribution systems.

show abstract

Section: Introductionmentioning

confidence: 57%

Experimental Studies on Thermophysical and Electrical Properties of Graphene–Transformer Oil Nanofluid

Almeida

Paul

Asirvatham

et al. 2020

Fluids

View full text Add to dashboard Cite

show abstract

“…Characteristics that could condition the convection performance of a coolant oil, such as viscosity, especially with natural flux, were not generally harmed by the presence of nanoparticles. Although slight increases were found [ 49 , 51 , 56 , 58 , 61 , 81 , 86 , 91 , 94 , 111 , 115 , 127 , 180 ], they were just as frequent as those with no effects [ 12 , 25 , 26 , 51 , 59 , 60 , 62 , 64 , 98 , 119 , 121 , 123 , 130 ]. Indeed, reductions in the viscosity were also noticed [ 22 , 51 , 84 , 91 , 95 ].…”

Section: Achievements Found In Literaturementioning

confidence: 99%

Mineral and Ester Nanofluids as Dielectric Cooling Liquid for Power Transformers

et al. 2022

View full text Add to dashboard Cite

Amidst the new techniques facing the improvement of cooling and insulating efficiency and the design of electric transformers, constrained by the current technologies, one of the more promising is the substitution of traditional dielectric oils for nanofluids. Research on nanofluids for their application in transformers as a coolant and dielectric medium have been performed during the last two decades and continue today. This review tries to collect and analyze the available information in this field and to offer it already dissected to researchers, focusing on the preparation methods and how nanoparticles affect the main properties of the base fluids. Here we also addressed the influence of different parameters as particle characteristics or environmental conditions in nanofluids performance, the evolution with time of the measured properties, or the neighboring relationship of nanofluids with other transformer components. In this sense, the most reviewed articles reflect enhancements of thermal conductivity or dielectric strength, as well as an improvement of time evolution of these properties, with respect to those that are found in base fluids, and, also, a better interaction between these nanofluids and dielectric cellulosics. Thus, the use of dielectric nanofluids in transformers may allow these machines to work safer or over their design parameters, reducing the risk of failure of the electrical networks and enhancing their life expectancy. Nevertheless, these advantages will not be useful unless a proper stability of nanofluids is ensured, which is achieved in a small part of revised articles. A compendium of the preparation methodology with this aim is proposed, to be checked in future works.

show abstract

“…The thermally influenced breakdown performance of nanofluids exhibited deteriorative behavior with increasing nanoparticle concentration. Recently, Rajnak et al [127] showed that the presence of magnetite nanoparticles in transformer oil does not necessarily yield an enhancement in the AC breakdown voltage. They discuss that the nanoparticle surface modification may play a decisive role in the breakdown mechanism.…”

Section: Li-bdvmentioning

confidence: 99%

Dielectric Fluids for Power Transformers with Special Emphasis on Biodegradable Nanofluids

2021

Self Cite

View full text Add to dashboard Cite

This review is focused on the research of dielectric fluids, especially commonly used power transformer oils enhanced by nanoparticles, i.e., nanofluids. There are differences between various combinations of base fluids and nanoparticles prepared in different ways. The main goal of this review was to present recent research in this field sorted by the used nanoparticles. Nanofluids based on mineral oils, natural, or synthetic esters were investigated in terms of the nature of nanoparticles, particularly Al2O3, TiO2, Fe2O3, Fe3O4, graphene, fullerene, and others. The combinations of environmentally friendly oils and nanoparticles were presented. Finally, the article focused on the description of current dielectric fluids usable in power transformers and the possibilities of improving new and existing fluids with nanoparticles, especially their physical, dielectric, and chemical properties, but with regard to environmental aspects.

show abstract

Statistical analysis of AC dielectric breakdown in transformer oil-based magnetic nanofluids

Cited by 22 publications

References 33 publications

Experimental Studies on Thermophysical and Electrical Properties of Graphene–Transformer Oil Nanofluid

Experimental Studies on Thermophysical and Electrical Properties of Graphene–Transformer Oil Nanofluid

Mineral and Ester Nanofluids as Dielectric Cooling Liquid for Power Transformers

Dielectric Fluids for Power Transformers with Special Emphasis on Biodegradable Nanofluids

Contact Info

Product

Resources

About