Article
Engineering, Electrical & Electronic
Jose E. Contreras, Josue Rodriguez, Carlos Gaytan
Summary: Currently, the use of new biodegradable dielectric liquids as an alternative to conventional mineral oil in transformers is being considered. However, the higher viscosity of ester liquids compared to mineral oil requires modifications in the impregnation process of insulation materials.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2022)
Article
Engineering, Electrical & Electronic
U. Mohan Rao, Issouf Fofana, Pawel Rozga, Patrick Picher, Dilip K. Sarkar, Rajan Karthikeyan
Summary: The focus of this study is on the oxidation aspects (gelling) of natural esters and its impact on the performance of transformer insulation systems. Even though natural esters are not suitable for breathing units, the scenario considered simulates a defect in the sealing system, allowing direct contact with atmospheric air. Commercially available natural ester liquids are thermally degraded under controlled aging conditions to observe the formation of sol and gel. The influence of sol and gel on the insulation is analyzed through physicochemical and electrical characterizations.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2023)
Article
Engineering, Electrical & Electronic
Matias Meira, Carlos Verucchi, Raul Alvarez, Leonardo Catalano
Summary: This study investigates the gas formation mechanisms of paraffinic-type mineral oil and soybean-based natural ester under thermal faults. Different gas profiles are generated for the two types of oils, with natural ester showing significant differences at low temperatures. The chemical structures of the natural ester behave similarly to carbon structures of mineral oil at temperatures above 700 degrees C.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2021)
Article
Chemistry, Analytical
Vijay V. Kondalkar, Jihoon Park, Keekeun Lee
Summary: This report introduces a MEMS gas sensor system for dissolved hydrogen gas analysis, providing effective monitoring of transformer operational status and maintenance of safety standards in the power grid.
SENSORS AND ACTUATORS B-CHEMICAL
(2021)
Article
Engineering, Electrical & Electronic
Josue Rodriguez, Jose Contreras, Carlos Gaytan
Summary: This study evaluates the gas generation of a new soybean-based natural ester liquid in distribution and power transformers through lab-scale testing, and discusses predicting transformer fault types using different diagnostic methods. Results show that overheating issues in natural esters are associated with ethylene, while high energy faults and partial discharge faults are linked to acetylene and hydrogen, respectively. The Duval triangle method is confirmed as the most reliable approach for diagnosing natural ester liquids.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2021)
Article
Engineering, Electrical & Electronic
Anupam Dixit, Chandima Ekanayake, Hui Ma, Tapan K. Saha, Muhammad Hafeez Ansari
Summary: This article investigates the temperature distribution of retrofilled layered winding natural cooling type distribution transformers. Computational fluid dynamics analysis and experimental data obtained through fiber optic sensors are used to compare the cooling performance of mineral oil-filled and natural ester oil-filled transformers. The findings can provide insights for decision-making regarding retrofilling of such transformers.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2022)
Article
Green & Sustainable Science & Technology
Anu Kumar Das, Dayal Ch Shill, Saibal Chatterjee
Summary: This paper examines the application of natural esters and new vegetable oils as alternatives to conventional mineral oils in the electric utility. It focuses on the dielectric performance and environmental safety of coconut oil, and discusses its sustainability and market potential.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2022)
Article
Energy & Fuels
Mateusz Cybulski, Piotr Przybylek
Summary: The research analyzed the application of molecular sieves in the drying process of transformer insulation systems, including the study and analysis of water sorption isotherms of various electro-insulating liquids, and the evaluation of the temperature effect on drying dynamics.
Review
Engineering, Electrical & Electronic
Mohd Syukri Ali, Ab Halim Abu Bakar, Azimah Omar, Amirul Syafiq Abdul Jaafar, Siti Hajar Mohamed
Summary: This review paper summarizes the discoveries made about dissolved gas analysis (DGA) conventional methods around the decade. It provides a brief introduction of DGA and reviews various fault detection methods such as the Key Gases Method, Duval Triangle Method, Duval Pentagon Method, and Ratio Methods. The paper highlights the importance of enhancing the reliability and accuracy of each DGA method in the diagnostic process to prevent further damage to transformers.
ELECTRIC POWER SYSTEMS RESEARCH
(2023)
Article
Engineering, Electrical & Electronic
Michel Duval, Jerzy Buchacz
Summary: Dissolved gas analysis and Duval Triangle 1 can differentiate between arcing faults in paper and in oil in transformers.
IEEE ELECTRICAL INSULATION MAGAZINE
(2022)
Article
Chemistry, Physical
Zaid B. Siddique, Soumen Basu, Prasenjit Basak
Summary: This paper focuses on studying the dielectric behavior of a mixture of natural ester oil and mineral oil blend dispersed with TiO2 and ZnO nanoparticles. The results show an overall enhancement in the dielectric properties of nanofluids, with improved breakdown voltage compared to pure mineral oil, pure ester oil, and the oil-blend. These nanofluids can be used as insulating oils in transformers, offering better cooling performance as well.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Engineering, Electrical & Electronic
Andres Montero, Belen Garcia, Juan Carlos Burgos
Summary: Retrofilling transformers with natural or synthetic esters reduces fire and environmental risks without requiring a large investment. While retrofilled transformers are currently predominantly used in medium power and voltage units, their use in higher rated power units is growing rapidly. Retrofilling presents challenges due to differences between mineral oil and esters, and the ability to perform the insulation and cooling functions must be reassessed. The study analyzed the electric field distribution of a retrofilled transformer and found that while certain parts of the insulation operate with lower stress when using esters, other regions experience significantly reduced dielectric margins.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2024)
Article
Chemistry, Physical
Bo Gao, Yanan Fang, Kai Liu, Haojie Yin, Yonghong Zeng, Guangning Wu
Summary: In this paper, molecular dynamics simulations were performed to study the thermal decomposition mechanism and product distribution of synthetic ester oils. The results show that the initial decomposition reaction is ester bond cleavage, followed by decarboxylation reaction and beta-C bond cleavage. The main decomposition products are CO2, C2H4, and some C2 and C3 species. The study of the generation process of these dissolved gases provides a theoretical basis for the research on the DGA method of synthetic ester oil.
CHEMICAL PHYSICS LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Jiefeng Liu, Boshu Song, Enze Zhang, Heng Zhang, Yiyi Zhang, Hui Hwang Goh
Summary: This work proposes a two-stage residual lifespan prediction model for insulating paper based on methanol and furfural indicators. The changes in the contents of methanol and furfural in the oil are examined to determine two demarcation points for dividing the insulation's life into different aging stages. By coupling with the second-order aging kinetic equation, the two-stage residual lifespan model is obtained. The proposed model is proven to be valid with a mean absolute percentage error of 5.6% for insulating paper's residual lifespan when compared to the conventional method of using a single indicator.
IEEE TRANSACTIONS ON POWER DELIVERY
(2023)
Article
Engineering, Electrical & Electronic
Yusuf Cilliyuz, Yunus Bicen, Faruk Aras, Guzide Aydugan
Summary: The use of natural esters as an insulating liquid has become popular since the early 2000s. While studies emphasize their environmental friendliness and safety, there is still a need for further experimental verification regarding their effectiveness in delaying the aging of cellulosic insulation material.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2021)
Article
Engineering, Electrical & Electronic
Daniel Martin, Tapan Saha, Tony Gray, Ken Wyper
IEEE ELECTRICAL INSULATION MAGAZINE
(2015)
Article
Engineering, Electrical & Electronic
Daniel Martin, Tapan Saha, Caesar Perkasa, Nick Lelekakis, Tim Gradnik
IEEE ELECTRICAL INSULATION MAGAZINE
(2016)
Article
Engineering, Electrical & Electronic
Yi Cui, Hui Ma, Tapan Saha, Chandima Ekanayake, Daniel Martin
IEEE TRANSACTIONS ON POWER DELIVERY
(2016)
Article
Engineering, Electrical & Electronic
Yi Cui, Hui Ma, Tapan Saha, Chandima Ekanayake, Daniel Martin
IET SCIENCE MEASUREMENT & TECHNOLOGY
(2016)
Article
Engineering, Electrical & Electronic
Daniel Martin, Judith Marks, Tapan Saha
IEEE ELECTRICAL INSULATION MAGAZINE
(2017)
Editorial Material
Engineering, Electrical & Electronic
Dan Martin
IEEE ELECTRICAL INSULATION MAGAZINE
(2017)
Review
Engineering, Electrical & Electronic
Daniel Martin, Tapan Saha
IEEE ELECTRICAL INSULATION MAGAZINE
(2017)
Article
Engineering, Electrical & Electronic
Daniel Martin, Olav Krause, Tapan Saha
IEEE TRANSACTIONS ON POWER DELIVERY
(2017)
Article
Engineering, Electrical & Electronic
Daniel Martin, Tapan Saha, Lindsay McPherson
IEEE ELECTRICAL INSULATION MAGAZINE
(2017)
Proceedings Paper
Computer Science, Interdisciplinary Applications
D. Martin, T. Saha, O. Krause, V. Clarkson
2016 IEEE INNOVATIVE SMART GRID TECHNOLOGIES - ASIA (ISGT-ASIA)
(2016)
Proceedings Paper
Computer Science, Interdisciplinary Applications
D. Martin, T. Saha, O. Krause
2016 IEEE INNOVATIVE SMART GRID TECHNOLOGIES - ASIA (ISGT-ASIA)
(2016)
Proceedings Paper
Engineering, Electrical & Electronic
Yi Cui, Daniel Martin, Tapan Saha, Hui Ma, Chandima Ekanayake, Nick Lelekakis
2015 IEEE 11TH INTERNATIONAL CONFERENCE ON THE PROPERTIES AND APPLICATIONS OF DIELECTRIC MATERIALS
(2015)
Proceedings Paper
Engineering, Electrical & Electronic
C. Y. Perkasa, N. Lelekakis, T. Czaszejko, D. Martin, T. Saha
2015 IEEE 11TH INTERNATIONAL CONFERENCE ON THE PROPERTIES AND APPLICATIONS OF DIELECTRIC MATERIALS
(2015)
Proceedings Paper
Engineering, Electrical & Electronic
D. Martin, O. Krause, T. Saha, C. Feely
2015 IEEE 11TH INTERNATIONAL CONFERENCE ON THE PROPERTIES AND APPLICATIONS OF DIELECTRIC MATERIALS
(2015)
Proceedings Paper
Energy & Fuels
Yi Cui, Hui Ma, Tapan Saha, Chandima Ekanayake, Daniel Martin
2015 IEEE POWER & ENERGY SOCIETY GENERAL MEETING
(2015)
