Impact of new uses on the thermal behaviour of a 30-40-year-old distribution transformer

Enedis operates 870,000 distribution transformers, some of which are more than 40 years old and will be facing new challenges: (i) the impact of climate change, which is likely to lead to a rise in temperature in MV/LV substations; (ii) new uses (electric vehicles, integration of renewable energies, etc.), which will globally increase the load on transformers. The article focuses on a realistic but rather pessimistic case study: a 400 kVA class C0Ck transformer, in a substation at the foot of a building, in an urban residential environment, supplying 265 households and located in Toulon (a city on the Mediterranean coast).The thermal calculations assess the ability of the 30-to 40-year-old transformers currently in service to meet the challenges of the next quarter century, which combine the effects of climate change and the integration of new residential uses.