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 core comprises a longitudinal axis, at least one multi-stranded conductor, at least one first conductor turn wound around the longitudinal axis, at least one second conductor turn wound around the longitudinal axis, the at least one first conductor turn being adjacent the at least one second conductor turn. Each of the at least one first and second conductor turns is provided with an electrically insulating member which extends about part but not an entire cross-sectional perimeter of the respective conductor turn, such that the at least one first and second conductor turns are insulated against each other. The electrically insulating member does not extend the entire cross-sectional perimeter of the respective conductor turn.

Abstract: A dry-type transformer, comprises a magnetic core, at least one high voltage (HV) winding, and at least one low voltage (LV) winding inductively coupled to the magnetic core. The transformer is made by determining a shape of an electric field that is generated, 3D printing a dielectric structure shaped to conform to the determined shape of the electric field, and mounting the dielectric structure between the HV and LV windings. A dielectric barrier arrangement for electrically isolating a coil of a transformer assembly from a further coil of the transformer assembly or from a core of the transformer assembly comprises a first dielectric structure having a first cylindrical dielectric structure extending along a longitudinal axis (L).

Abstract: Non-liquid immersed transformers and methods of measuring aging degree of the transformers' insulation are disclosed. The transformers comprise a solid insulation inside the conductive coil and one or more floating electrodes in the solid insulation. At least a part of the conductive coil and the one or more floating electrodes may form one or more capacitive elements, respectively. An electrical parameter, e.g. complex permittivity, of the capacitive element is measured and the aging degree is calculated as a function of the electrical parameter measurement.

Abstract: Dry-type transformers with insulating modules are disclosed. Example insulating modules include dielectric screens and supporting blocks. The supporting blocks support the dielectric screens over windings of the transformer. The dielectric screens have first substantially even portions configured to adapt in spaces defined by corresponding cylindrical barriers arranged between first and second windings of the transformers and second substantially even portions, transversal to the first portions and to the first windings of the transformers and extending outwards from the first portions and beyond the supporting blocks. The dielectric screens partly extend around a winding.

Abstract: A transformer may comprise a winding wrapped around a magnetic core, the winding having at least one winding portion extending between the magnetic core and the exterior of the winding in radial direction. The winding may comprise at least a first conductor and at least a second conductor, arranged radially adjacent to each other in each winding portion with the interposition of an insulating layer, wherein the first conductor is arranged radially inwardly with respect to the second conductor for part of each winding portion length, and radially outwardly with respect to the second conductor for another part of each winding portion length.

Abstract: A dry-type electrical transformer includes a coil assembly having at least one winding wound into a plurality of concentric turns, at least one cooling sector defined between adjacent concentric turns, spacers positioned inside the cooling sector and spaced from each other to allow a plurality of air ducts each defined between two adjacent spacers, and at least one electrical shield positioned in the cooling sector and arranged to electrically shield the air ducts. At least one electrical shield is positioned in the cooling sector and arranged to electrically shield the air ducts. The electrical shield include a first end edge connected to the turn at the inner side of the cooling sector, a second end edge which is free and electrically insulated from the surrounding parts, and a central portion extending between the first and second end edges and is positioned at the outer side of the spacers.