Abstract: In some embodiments, a shielded coil assembly is provided that includes (1) a coil having an outer surface, an inner surface, an upper end surface and a lower end surface and a first insulating material formed over the outer surface, inner surface, upper end surface and lower end surface of the coil; and (2) a conductive shield comprising a conductive paint applied along the first insulating material so that the conductive paint extends over at least a portion of each of the outer surface, inner surface, upper end surface, and lower end surface of the coil. In one or more embodiments, a dry-type transformer may be formed using the shielded coil assembly. Numerous other embodiments are provided.

Abstract: A transformer for mounting on a mast of an air-insulated energy distribution network has a core which is protected against corrosion and environmental influences, while at the same time stable retention is provided. The transformer contains a winding block having a solid insulating body, in which at least one upper voltage winding and at least one lower voltage winding are arranged. The winding block delimits a completely peripherally closed central retention opening. Furthermore, a core unit is provided which has at least one magnetizable core and is inductively coupled to each lower voltage winding by each upper voltage winding. The core unit extends through the retention opening via at least one core leg and annularly extends around the winding block on the outside by a ring portion. Retention devices are provided for fastening the ring portion to the mast.

Abstract: A winding unit for connecting to a high-voltage grid or network includes a winding embedded in a solid insulating body and a first main connection terminal connected to a first winding end of the winding and disposed on a first support formed on the insulating body. A second main connection terminal is connected to a second winding end of the winding. The winding has partial windings and taps for adjusting the number of windings of the partial windings connected in series. Outgoing lines extending in the insulating body connect the taps to a tap connection terminal accessible from the outside. The tap connection terminals are formed on the support in order to encapsulate the higher voltage in a resin block over the entire periphery by using a shielding cage.

Abstract: A sealed core-coil assembly in a submersible transformer includes a coil assembly having an inner coil with inner, outer, upper, and lower surfaces, and an outer coil with inner, outer, upper, and lower surfaces, a core assembly including a core window and core column of a magnetically-permeable material, the core column and core window having inner side surfaces, and an expandable sealing member including an inner cavity that is fillable or evacuatable so that a compliant insulation material is positioned in the inner cavity to block passage of water and prevent the formation of a loop of water, which otherwise would act like an electrical short in a submerged transformer.

Abstract: A transformer core for a dry-type transformer includes a laminated construction having several groups of stacked laminations that form a step-lap sequence of laminations. Each group in the step-lap sequence has a mean length different than an adjacent group in the step-lap sequence and has at least two identical laminations per group, wherein at least one group has at least four identical laminations. Methods of assembling a transformer core are also provided, as are other aspects.

Abstract: A tap changer assembly of a dry-type transformer. The tap changer assembly includes a first molding including multiple taps, a semi-conductive coating applied to the first molding, a conductive shield provided overtop some of the semi-conductive coating, a grounding member comprising a ring of bosses interconnected by a grounding conductor connected to the conductive shield, a second molding applied over at least a portion of the conductive shield and the grounding conductor, the second molding forming a molded sealing surface, a conductive cover coupled to the ring of bosses; and a sealing member sealing a space between the molded sealing surface and the conductive cover. Dry-type transformers and methods of forming a tap changer assembly of a dry-type transformer are provided, as are numerous other aspects.

Abstract: A sealed core-coil assembly includes a coil assembly having an inner coil with inner, outer, upper, and lower surfaces, and an outer coil with inner, outer, upper, and lower surfaces, a core assembly including a core window and core column of a magnetically-permeable material, the core column and core window having inner side surfaces, and an expandable sealing member including an inner cavity that is fillable or evacuatable. An expandable sealing member is provided between: one or more inner side surfaces of the core column and one or more inner surfaces of the inner coil, the outer surface of the inner coil and the inner surface of the outer coil, and between the upper and lower surfaces of the inner and outer coils and the inner side surfaces of the core window. Core-coil assemblies, sealing assemblies, and sealing methods are provided, as are numerous other aspects.

Abstract: In some embodiments, a connection bar is provided for connecting multiple high voltage coils of a dry-type transformer along a top or bottom of the dry-type transformer. The connection bar includes (1) an electrically insulating body having a plurality of openings, each opening sized to receive at least one of high voltage terminals of the transformer; (2) an electrical connection pathway within the electrically insulating body configured to create a predetermined electrical connection between multiple high voltage coils of the transformer; (3) external connector terminals embedded within and extending from the electrically insulating body, the external connector terminals connected to the electrical connection pathway; and (4) a ground shield embedded within the electrically insulating body and configured to shield high voltage terminals of each high voltage coil of the transformer. Numerous other aspects are provided.

Abstract: In some embodiments, a shielded coil assembly is provided that includes (1) a coil having an outer surface, an inner surface, an upper end surface and a lower end surface and a first insulating material formed over the outer surface, inner surface, upper end surface and lower end surface of the coil; and (2) a conductive shield comprising a conductive paint applied along the first insulating material so that the conductive paint extends over at least a portion of each of the outer surface, inner surface, upper end surface, and lower end surface of the coil. In one or more embodiments, a dry-type transformer may be formed using the shielded coil assembly. Numerous other embodiments are provided.

Abstract: A transformer core for a dry-type transformer includes a laminated construction having several groups of stacked laminations that form a step-lap sequence of laminations. Each group in the step-lap sequence has a mean length different than an adjacent group in the step-lap sequence and has at least two identical laminations per group, wherein at least one group has at least four identical laminations. Methods of assembling a transformer core are also provided, as are other aspects.

Abstract: A tap changer assembly of a dry-type transformer. The tap changer assembly includes a first molding including multiple taps, a semi-conductive coating applied to the first molding, a conductive shield provided overtop some of the semi-conductive coating, a grounding member comprising a ring of bosses interconnected by a grounding conductor connected to the conductive shield, a second molding applied over at least a portion of the conductive shield and the grounding conductor, the second molding forming a molded sealing surface, a conductive cover coupled to the ring of bosses; and a sealing member sealing a space between the molded sealing surface and the conductive cover. Dry-type transformers and methods of forming a tap changer assembly of a dry-type transformer are provided, as are numerous other aspects.

Abstract: In some embodiments, a connection bar is provided for connecting multiple high voltage coils of a dry-type transformer along a top or bottom of the dry-type transformer. The connection bar includes (1) an electrically insulating body having a plurality of openings, each opening sized to receive at least one of high voltage terminals of the transformer; (2) an electrical connection pathway within the electrically insulating body configured to create a predetermined electrical connection between multiple high voltage coils of the transformer; (3) external connector terminals embedded within and extending from the electrically insulating body, the external connector terminals connected to the electrical connection pathway; and (4) a ground shield embedded within the electrically insulating body and configured to shield high voltage terminals of each high voltage coil of the transformer. Numerous other aspects are provided.

Abstract: A transformer for mounting on a mast of an air-insulated energy distribution network has a core which is protected against corrosion and environmental influences, while at the same time stable retention is provided. The transformer contains a winding block having a solid insulating body, in which at least one upper voltage winding and at least one lower voltage winding are arranged. The winding block delimits a completely peripherally closed central retention opening. Furthermore, a core unit is provided which has at least one magnetizable core and is inductively coupled to each lower voltage winding by each upper voltage winding. The core unit extends through the retention opening via at least one core leg and annularly extends around the winding block on the outside by a ring portion. Retention devices are provided for fastening the ring portion to the mast.

Abstract: A winding unit for connecting to a high-voltage grid or network includes a winding embedded in a solid insulating body and a first main connection terminal connected to a first winding end of the winding and disposed on a first support formed on the insulating body. A second main connection terminal is connected to a second winding end of the winding. The winding has partial windings and taps for adjusting the number of windings of the partial windings connected in series. Outgoing lines extending in the insulating body connect the taps to a tap connection terminal accessible from the outside. The tap connection terminals are formed on the support in order to encapsulate the higher voltage in a resin block over the entire periphery by using a shielding cage.

Abstract: In a cost-effective and qualitatively better method for producing spacers for a winding unit of an electrical high-voltage device, at least two starting components are mixed together in a mixing chamber under vacuum to form a component mixture. The component mixture is transferred to an extrusion housing, likewise under vacuum, of an extruder in which a transport device is arranged and which is equipped with a mouthpiece delimiting an outlet opening. The extrudate exiting from the mouthpiece is cured by the addition of heat in a vacuum in order to obtain the spacers.