transformers are unaffordable. That is why EDF R&D has
worked on a new insulating liquid, based on vegetable oil and
derivatives, which can be used in MV/LV transformers without
requiring any change in their current design.
This paper presents the low-viscosity ester composition
resulting from this project, which shows properties very similar
to those of the standard insulating mineral oils, and it reports
the results of the studies carried out to assess its behavior, in
laboratory and into real transformers on the distribution
network.