CHENNAI: TANGEDCO's Research and Development wing has a patent for the concept of "Flexible External Bellow for Insulation Protection of Transformer" to protect transformers from moisture.

In a statement, TANGEDCO said that the patent has been granted for 20 years from April 16, 2015.

Pointing out that moisture is one of the degrading agents to the transformer's life, it said that the conventional procedures employed to reduce moisture are inadequate, costly and complex.

"In this invention, a sealed expandable bellow is connected after the silica gel breather of the transformer. The conservator air space is filled with dry Nitrogen. When transformer oil expands, nitrogen gas in the conservator is pushed into the bellow. The reverse action happens at low loads. The size of the bellow can be decided based on the capacity of the transformer. The system would make a transformer a sealed type, providing complete immunity from external moisture and oxygen. It reduces transformer maintenance costs, time and failures, " it said.