A casting dry-type transformer and a manufacturing method thereof are disclosed. The transformer includes a coil, an iron core, a clamp and a leading wire. The leading wire is led out from the coil, the coil is arranged on the iron core, the coil and the iron core are fixed together by the clamp at two sides, the coil is provided with a casting die, the casting die is provided with evenly distributed channels, a transformer body is placed into a casting tank to cast a transformer, and a casting material is easy to penetrate into the coil through a reserved channel.

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.

Provided is a three-phase dry-type transformer. The three-phase dry-type transformer comprises three single-phase dry-type transformers connected to each other. Each single-phase transformer comprises an incoming line side high-voltage coil and an outgoing line side high-voltage coil, wherein the incoming line side high-voltage coil is provided with an incoming line end and an outgoing line end, and the outgoing line side high-voltage coil is provided with an incoming line end and an outgoing line end. The outgoing line end of the incoming line side high-voltage coil is connected to the incoming line end of the outgoing line side high-voltage coil, such that the incoming line side high-voltage coil and the outgoing line side high-voltage coil are connected in series. Further provided is an assembly method.

The present disclosure relates to electrical windings for a dry transformer which allows construction of a compact dry transformer even in relatively high voltage classes. For this purpose, the electrical winding has multiple windings of a winding conductor wound to form a coil. The coil has been embedded into a solid insulation body. In some embodiments, a coating of an electrically conductive material, comprising a resin matrix with at least 0.05% by weight of nanoscale filler, has been applied to at least one surface of the insulation body.

A transformer is disclosed. The transformer includes a first coil including a first stack of wire disks stacked in a first direction; an exterior barrier arranged to form a first air gap between outer sides of the wire disks of the first stack of wire disks and the exterior barrier; an interior barrier arranged to form a second air gap between inner sides of the wire disks of the first stack of wire disks and the interior barrier; a wind generator arranged to generate an air flow in the first direction; a core in the form of a cylinder that is surrounded by the first coil; and an air guiding plate fixed to one of the exterior barrier and the interior barrier, to guide the air flow in a second direction along first stack gaps between the wire disks of the first stack of wire disks. The transformer effectively improves the heat dissipation of the coil and thus allows a smaller transformer in size.

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.

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.

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.

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.

An apparatus includes a temperature sensor configured to measure a temperature of a dry-type transformer, and the temperature sensor is arranged on or proximate a conductor of the dry-type transformer and is covered by an insulating layer of the conductor. The apparatus further includes a passive wireless communication module configured to transmit the measured temperature to a reader. The temperature of the dry-type transformer can be measured accurately, thereby improving the reliability and safety of the dry-type transformer. Accordingly, temperature measurement for the dry-type transformer can work appropriately in a cost-effective and efficient way.