Comparison of dielectric properties of olive oil, mineral oil, and other natural and synthetic ester liquids under AC and lightning impulse stresses

Reffas, Abderrahim; Moulai, H.; Béroual, Abderrahmane

doi:10.1109/tdei.2018.007218

Cited by 57 publications

(23 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These issues concerning effects on streamer development, including the analysis and modeling of streamers, which will be useful for researchers and designers, are documented in [82], [83]. Recently, rapeseed oil, soybean oil and modified palm oil have been investigated for streamer characteristics in comparison to mineral oils [84]- [89]. The emphasis was on streamer shape (horizontal and vertical) for point plane electrode configuration under positive and negative polarities.…”

Section: Pre-breakdown Phenomenamentioning

confidence: 99%

Alternative Dielectric Fluids for Transformer Insulation System: Progress, Challenges, and Future Prospects

et al. 2019

View full text Add to dashboard Cite

Ester-based dielectric fluids have gained widespread popularity for applications in high voltage apparatus. Synthetic and natural esters have been subjected to research for decades vis-à-vis mineral insulating oils around the world. Although many researchers favor the application of ester fluids, utilities are still uncertain and application of these alternatives remains a challenge. The intent of this survey is to present recent research progress and highlight the state of the art of key aspects that should be emphasized in future research. The contemporary research scenarios pertaining to the performance of ester fluids versus mineral oils, miscibility, and retrofilling of insulating fluids are discussed. In addition, pre-breakdown phenomena, usage of esters in on-load tap changers, environmental and fire resistance properties, and use of esters in cold climates are also discussed. Importantly, challenges and future aspects that should be investigated to improve the existing knowledge of ester dielectric fluids for applications in transformer technology are highlighted.

show abstract

Section: Pre-breakdown Phenomenamentioning

confidence: 99%

Alternative Dielectric Fluids for Transformer Insulation System: Progress, Challenges, and Future Prospects

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Therefore, the underlying mechanisms of this phenomenon have been receiving increasing attention. The comparison of pre-breakdown phenomenon (streamers) characteristics in MO and NEO has been reported [15,[17][18][19]. The inception voltage of streamers in NEO is lower under both polarities compared with that of MO in the non-uniform field.…”

Section: Introductionmentioning

confidence: 99%

“…2020, 21, 974 2 of 13The LI V b of ester insulation oil is comparable to that of MO in a quasi-uniform field [12][13][14]. However, in a non-uniform field, the LI V b of NEO is considerably lower than that of MO for large oil gaps [11,15,16], which limits the application of NEO in large power transformers. Therefore, the underlying mechanisms of this phenomenon have been receiving increasing attention.…”

mentioning

confidence: 99%

Relationship between the Electrical Characteristics of Molecules and Fast Streamers in Ester Insulation Oil

Wang

Lou

et al. 2020

IJMS

View full text Add to dashboard Cite

The effects of C=C, ester and β-H groups on the ionization potential (IP) and electron affinity (EA) of molecules in natural ester insulation oil were investigated by density functional theory (DFT). The major contribution to the highest occupied molecular orbital (HOMO) comes from the carbon atoms adjacent to C=C. Thus, the IPs of triglycerides decrease as the number of C=C double bonds increases. The C=C in alkanes may also lower the IP. However, the β-H in triglycerides has little effect on the IP, and C=C and β-H have only a small effect on the EAs of the triglycerides because of the major contributions of atoms near the ester group in triglycerides to the lowest unoccupied molecular orbital (LUMO). This study calculated the IPs of 53 kinds of molecules in FR3, which are significantly lower compared with those of molecules in mineral oil (MO) and trimethylolpropane triester without C=C. However, the lightning impulse breakdown voltage (LI V b ) of trimethylolpropane triester is still significantly lower than that of MO at the large gap. Therefore, the transition from slow to fast streamers under low lighting impulse voltage is determined by the ester group rather than by C=C and β-H. The ester group may attract more electrons, impacting itself more compared to alkane in MO and facilitating the transition from slow to fast streamers. Int. J. Mol. Sci. 2020, 21, 974 2 of 13The LI V b of ester insulation oil is comparable to that of MO in a quasi-uniform field [12][13][14]. However, in a non-uniform field, the LI V b of NEO is considerably lower than that of MO for large oil gaps [11,15,16], which limits the application of NEO in large power transformers. Therefore, the underlying mechanisms of this phenomenon have been receiving increasing attention. The comparison of pre-breakdown phenomenon (streamers) characteristics in MO and NEO has been reported [15,[17][18][19]. The inception voltage of streamers in NEO is lower under both polarities compared with that of MO in the non-uniform field. Streamer propagation in NEO evolves easily to fast mode, which results in its considerable low LI V b at large oil gaps [16,20]. Comparisons of discharge parameters between NEO and MO were performed by many researchers. However, the reasons why streamer propagation in NEO evolves more easily to fast mode compared with that in MO is still unknown. Therefore, it is necessary to study the relationship between the electrical characteristics of the molecules and fast streamers in insulation oils.The IP and EA of molecules are related to the propagation of streamers in insulation oils [21,22]. Thus, density functional theory (DFT) was applied to calculate the IP and EA values of the molecules; DFT is the most widely used theoretical method to simulate the properties of both organic and inorganic molecules [23]. Specifically, the C=C, ester and β-H groups are the important groups in NEO. Therefore, in this work, the effects of the C=C, ester and β-H groups on the IP and EA values of molecules in NEO were investigated. Then, compari...

show abstract

“…As it was seen in the section 2.2.1, one of the most important parameters to know the quality of an insulating oil is the AC BV. Many authors have studied the effect of dispersing NP in the AC BV of the MO as part of the method of characterization of oils, as described by [101,102,103]. This method has also been used to see if there is an improvement in the NDF respect to their base oils as reference [104].…”

Section: Chapter 4 Ac Breakdown Voltage Of Mineral Oil Based Nanodielectric Fluidsmentioning

confidence: 99%

Analysis of Water Solubility in natural-ester based nanodielectric fluids

Perez

García

Primo

et al. 2019

2019 IEEE 20th International Conference on Dielectric Liquids (ICDL)

View full text Add to dashboard Cite

Una tesis doctoral viene firmada por una sola persona, pero hay mucha gente que de un modo u otro ha participado en que esta sea posible, por eso quiero agradecérselo a todas esas personas.En primer lugar, quiero expresar mi más sincera gratitud a mis tutores Dr. Juan Carlos Burgos y Dra. Belén García, por darme la oportunidad de realizar mi tesis doctoral con ellos. Su amplio conocimiento y su nivel de esfuerzo e implicación son inestimables para la finalización de este trabajo. Desde un primer momento creyeron en mi y me han ayudado en todo momento durante este recorrido de más de cuatro años. Gracias.También quiero aprovechar la oportunidad para agradecer a la Universidad Carlos III de Madrid la oportunidad que brinda ofreciendo los contratos predoctorales para poder cursar una tesis doctoral formándonos, además, como profesores. Así mismo, quiero agradecer al resto de personal del departamento de Ingeniería Eléctrica, especialmente al Dr. Guillermo Robles y al Dr. Juan Manuel Martínez con los que he compartido congresos y buenos momentos y a Cristina Vega por su buen humor todas las mañanas.Además, en el plano profesional tengo que dar mi gratitud a los profesores

show abstract

Comparison of dielectric properties of olive oil, mineral oil, and other natural and synthetic ester liquids under AC and lightning impulse stresses

Cited by 57 publications

References 28 publications

Alternative Dielectric Fluids for Transformer Insulation System: Progress, Challenges, and Future Prospects

Alternative Dielectric Fluids for Transformer Insulation System: Progress, Challenges, and Future Prospects

Relationship between the Electrical Characteristics of Molecules and Fast Streamers in Ester Insulation Oil

Analysis of Water Solubility in natural-ester based nanodielectric fluids

Contact Info

Product

Resources

About