03/03/2023
CIGRE's STUDIES SHOWED THAT ONE OF EVERY 200 POWER TRANSFORMERS FAILS EACH YEAR!
It is enormous capital annual loss (transformer replacement/repair costs, lost production, and penalties).
Power Transformers are one of the most expensive and vital power network elements. There have been many reliability and failure causes studies performed in the past covering different aspects such as Cigre TB 767, C57.93-2019 - IEEE Guide for Installation and Maintenance of Liquid-Immersed Power Transformers.
New materials are available on the market and technology is improving but on the other hand the market is pushing the design to reduced end prices. The effect of this is that the failure rate is not decreasing. 60 years ago, transformers were designed with 2 tons transformer oil per MWA. Now it is reduced 7 times to 2 tones per 14 MWA. The power and voltage levels are constantly growing and are now >7 times higher than 60 years ago.
Proper trainings can improve maintenance practices, and this can slightly reduce the failure rates by 20%. But the design will keep on pushing the limits and Transformers will continue to fail.
The challenge of technological improvement will be to reduce the rest of the 80% of failures or at least reduce their impact. With the monitoring possibilities available today all failures can be detected at the very early stage often resulting in millions of USD savings per failure.
