Solutions for improving maintenance operations on power transformers in primary substations

The maintenance of apparatus operating on the electrical networks can be improved following the total cost evaluation approach. Power transformers to be installed in primary substations - typical ratings: 40 MVA, 150 kV/20 kV - have been implemented taking into account the maintenance operations to be performed in all their expected life. This paper describes the main improvements that have been adopted or that are going to be adopted on transformers and relevant accessories in Enel Distribuzione. Moreover economical evaluations, quality of energy supply implications as well as safety and environmental considerations are reported.