Improvements for the Drying and Insulation of Power Transformers with Related Technology

Power transformers in different designs and sizes are used for many decades. When it comes to drying and insulation methods, many improvements have been made in the past.

For oil-filled transformers, the hot-air drying process has been substituted mainly by Vapour Phase for high-voltage transformers.

For medium-voltage transformers, the low-frequency heating process (LFH) becomes more and more applicable. An alternative method for insulation is dry-type transformers according to different casting methods for epoxy resin.

The methods and the related machinery is presented in this paper.