Natural esters for life and capacity enhancement of distribution transformers

Abstract

Ageing assets of any electrical utility are a reality; the challenge is not in replacing these assets by incurring huge capital expenditure but in enhancing the life of existing assets. This involves re-engineering of existing installations by developing retrofit solutions so as to accommodate the reengineered solutions in the existing space and at a substantially reduced capital expenditure. Retro filling of mineral oil filled transformers by natural esters has given multiple benefits of enhanced fire safety, enhanced life of the paper by virtue of the fact that natural esters have an inherent property of absorbing moisture from the paper insulation that is impregnated with, further the temperature rise offered by natural esters are higher than that by mineral oil. Tata Power has adopted the best practice of retro filling mineral oil filled transformers that are optimally loaded and more than 15 years old with natural esters. Condition monitoring of these transformers over a period of time has clearly depicted that retro filling of distribution transformers by replacing traditional mineral oil with natural ester oil is a financially viable solution for enhancement of transformer capacity, life, safety, & environment friendly.