ABB has successfully tested a cost-effective way to replace petroleum-based mineral oil insulating medium with environmentally friendly natural ester fluid in the world's largest sealed 200 megavolt ampere (MVA), 420 kilovolt (kV) single-phase transformer. This significant technology breakthrough pushes the development of environmentally friendly high-voltage (HV) power transformers to a new level.
Transformer manufacturers have traditionally used petroleum-derived mineral oil as an insulating fluid. Today, ABB increasingly uses ester insulators made from synthetic or vegetable oil, because they are biodegradable, non-toxic and offer much greater fire resistance.
"This project is very much in line with our vision of making new and existing high-voltage transformer products safer and greener, without compromising their performance," said Markus Heimbach, head of ABB's Transformers business, a part of the company's Power Grids division. "We are committed to supporting our customer's environmental initiatives with high-performance transformer products and designs that are environmentally friendly, energy efficient and provide a reliable high-voltage alternative for a sustainable future."
ABB developed a solution that avoids changing the costliest, most complex parts of a transformer so units already in service can be drained of mineral oil and refilled with natural ester fluid, keeping costs and conversion times to a minimum. Using state-of-the-art simulation and evaluation tools, ABB converted an existing 420 kV transformer from mineral oil to ester by only changing the bushings, tap changer and insulation medium.
ABB pioneered the use of ester fluid in the 1990s, and has extensive knowledge and research data on its performance in different transformer types and voltages and this insulating solution can also be applied to new power transformers rated up to 550 kV.
