A three-phase dry distribution transformer adapted for mounting outdoors on a pad or to a utility pole. The distribution transformer includes one or more winding assemblies mounted to a ferromagnetic core. Each winding assembly includes a low voltage winding and a high voltage winding. In each winding assembly, an encasement comprised of an insulating resin encapsulates the low voltage and high voltage windings. The encasement includes a body and a pair of high voltage bushings and a pair of low voltage bushing.

A transformer cooling system, includes a dry transformer having a core including a leg, a winding body arranged around the leg, and a cooling channel extending in a direction of a longitudinal axis of the winding body. The cooling channel is disposed between an inner part of the winding body and an outer part of the winding body. The transformer cooling system further includes a housing for containing the dry transformer. The housing has an inlet portion for receiving air from outside the housing and an outlet portion for expelling air outside the housing. The transformer cooling system further includes a flow generating device arranged at the outlet portion and adapted to generate an under pressure for sucking the air from the inlet portion towards the flow generating device and to expel the air through the outlet portion outside the housing.

A dry transformer to be mounted on or under or in a vessel or means of transportation, in particular a rail car or power car of a train or a ship, includes at least one core and at least one winding. The winding surrounds the core and the core and the winding are parts of a coil. The coil and/or the core and/or the winding are mechanically connected to an outer support structure by at least one strut. The transformer is able to master the required typical dynamic loads in at least one direction in transportation applications, such as railway applications.