New technology to lower environmental impact of HV transformers

ABB has successfully tested a new solution to replace petroleum-based mineral oil insulating medium with environmentally friendly natural ester fluid in the world’s largest sealed 200 MVA, 420 kV single-phase transformer.

Ester insulators made from synthetic or vegetable oil are biodegradable, non-toxic and offer greater fire resistance.

The new solution 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, according to the manufacturer.

Using the simulation and evaluation tools, the manufacturer converted an existing 420 kV transformer from mineral oil to ester by only changing the bushings, tap changer and insulation medium.

Source: ABB