Abstract: A transformer includes a plurality of windings including a first winding and a second winding, wherein the first winding includes a first winding portion and a second winding portion at a second position in the axial direction and in the radial direction, the first position different from the second position, the number of turns of the first winding portion being different from the number of turns of the second winding portion, wherein the second winding includes a third winding portion at a third position and a fourth winding portion at a fourth position in the axial direction and in the radial direction, the third position different from the fourth position in the axial direction, and the number of turns of the third winding portion being different from the number of turns of the fourth winding portion.

Abstract: A transformer installation including at least one non-liquid immersed transformer having a magnetic core including at least two core legs each having a winding axis. The transformer further includes at least two coil windings wound around at least one of the core legs of the magnetic core about the winding axis. The transformer installation further includes at least one coil cooling tube defining a coil cooling channel for guiding a dielectric cooling fluid. The at least one cooling tube is wound about at least one of the at least two coil windings. The transformer installation further includes at least one core cooling channel arranged within the core. The core cooling channel is configured to guide a dielectric cooling fluid through the core.

Abstract: A coil for a transformer assembly is provided. The coil extends circumferentially around a longitudinal axis. The coil comprises a foil winding arrangement and a conductor element. The foil winding arrangement extends circumferentially around the longitudinal axis and has four edge regions. The conductor element covers at least partially at least one of the edge regions of the foil winding arrangement. The conductor element allows for a reduction in an electric field that arises during an operation of the transformer assembly at the edges of the foil winding arrangement. In this manner, a performance improvement in partial discharge tests and lightning impulse tests can be achieved.