Present & future generation dielectric fluids for power transformers & shunt reactors

Today's transmission and distribution systems are continuously expanding to evacuate ever growing power generation in all parts of the world. Along with the continuous growth in demand for electrical energy the nature of demand has also become more complex. Large and growing urban agglomerations driving economic growth, demands safe uninterrupted quality electrical power. To ensure a high degree of reliability it is of utmost importance that all critical equipments like transformers, shunt reactors, switch gears and capacitors in the transmission & distribution grid perform at rated capacity unfailingly without compromising on the safety aspects.

Mineral oil based dielectric fluids have been integral part of transformers starting from 1890 and continue to be the preferred medium due its track record, good performance and competitive costs. As the generation and transmission systems grew from, LV, MV, HV, EHV & UHV the quality of dielectric fluids also kept pace to conform to the rigid standards, thanks to the technological advancements in refining. Modern catalytic hydro processed mineral dielectric fluids apart from meeting the thermal and electrical stresses constantly varying due to load factors have also proven characteristics to comply with environmental issues; a major factor in the present times. We have the present generation mineral oil based dielectric fluids, synthetic ester and natural ester-based fluids fulfilling all these requirements.

Dielectric fluids have to be chosen based on the specific applications involved. Distribution systems in densely populated areas, traction, marine and coal mines all require high fire point & flash point dielectric fluids with biodegradability. Outdoor substation transformers may demand highly reliable and eco-friendly modern catalytic hydro processed dielectric fluids. Similarly, hermetically sealed Instrument transformers & bushings may require environmentally friendly fluids with gas absorbing property.

In this paper we present the results of our extensive studies carried out on the performance of present & future generation dielectric fluids and synthetic esters in the laboratory condition and through field studies.