Impact of the recent EU regulation on HV/MV transformers: Possible technical-economic benefits arising from the replacement of old transformers. Two case studies

The paper presents an economic study concerning the replacement of HV/MV power transformers (TRs) according to the requirements recently introduced in the Commission Regulation EU n°548/2014 (Tier I and Tier II class transformers). Two case studies based on measured yearly load profiles of existing TRs, referring to two primary substations in a MV distribution network, have been carried out. A Monte Carlo procedure has been implemented in order to predict 20-year timespan load profiles, according to three different scenarios (constant load, load increase and load decrease). Results show that the convenience of transformer replacement is strongly dependent on the energy cost.