Over the past decade, the shift to revitalizing old transformers with natural or synthetic esters has triggered a significant trend. This approach has been working together to reduce the risk of fire and environmental damage while strengthening the transformer’s ability to handle increased loads. Compared to traditional mineral oils, these esters can be distinguished by their biodegradability and higher fire separation, which promises to be a safer and more sustainable alternative. In addition to safety, they also provide a blessing for the life of the transformer by slowing down the aging process of solid insulation. This is through the migration of enhanced moisture from solid insulation to liquids into liquid chemistry, a chemical process known as transesterification, which takes place in the presence of ester. As a result, transformers can tolerate higher operational needs without reducing their expected service life, a leap in enhancing the reliability and sustainability of power systems.
Leading an innovative research, Andrés Montero, Belén García and Juan Carlos Burgos of the University of Charles III in Madrid ) explores the electric field distribution of transformers modified with natural ester under alternating current (AC) pressure. Their findings, published in the International Journal of Electricity and Energy Systems, highlighted the critical transition from traditional mineral oils to natural esters. This shift is designed to mitigate fire hazards and minimize environmental impacts without the need for large financial expenditures.
The core of their research is the subtle influence of reversing the electric field distribution within the Transformers (replicating mineral oil with natural ester mineral oil), a key factor in ensuring operational safety and efficiency. The team used a finite element method, a complex modeling technique, to carefully examine the distribution of electric field in high-capacity transformers originally designed for mineral oil. This approach allows researchers to learn in detail how changes in insulation materials affect the internal electric field of the transformer.
Montero highlights the nature of their approach and explains: “We modeled a high-capacity transformer using advanced simulation software designed for major power loads. Our goal is to understand how natural esters can be used instead of mineral oil. This approach illuminates the potential benefits and challenges of using natural esters and demonstrates the team’s commitment to enhancing transformer safety.
Montero and his colleagues’ findings reveal the complexity of the electric field distribution, highlighting areas where insulation stress is reduced, thus potentially improving safety. However, in some areas, especially those involving solid insulation in high pressure areas, the dielectric distance is reduced. “When the transformer is refurbished, weaknesses may appear in the solid insulation layer on the surface of the conductor in the highest electric field area of the transformer,” Montero noted, emphasizing the complex balance between material properties and transformer performance. The implications of this study go beyond direct security improvements. “Reversal is not inherent to the transformer’s dielectric performance, despite significant changes in the electric field distribution,” Montero added. This nuanced understanding is crucial for developing safer and more environmentally friendly power systems.
Journal Reference
Andrés Montero, Belén García, Juan Carlos Burgos, “Electric Field Distribution in Deformer Transformers Used by Natural Persons under AC Pressure”, International Journal of Electric Power and Energy Systems, 2024.
doi: https://doi.org/10.1016/j.ijepes.2023.109549.
About the Author
Andres Montero (BSC’17, M’20, PhD’23) was born in Cuenca in 1995. In 2017, he received his bachelor’s degree. Degree in Industrial Engineering from the University of Valencia, Spain and degree in Industrial Engineering from the University of Valencia in 2020 and Masters in Electrical Engineering from Politecnico di Milano, Italy. He has been a PhD since 2020. Student of the Department of Electrical Engineering, Carlos III University. His main topic of interest is to study the inversion process of transformers with biodegradable fluids.
