what is the function of buchholz relay in power transformer?

The Buchholz relay is a safety device used in oil-filled power transformers. Its primary function is to detect gas accumulation and oil flow changes within the transformer. When a fault occurs, such as a short circuit, it generates gas bubbles that rise to the relay. The Buchholz relay triggers an alarm or disconnects the transformer, preventing further damage. This early detection helps ensure the safe operation of the transformer and protects against catastrophic failures.