SE511161C2 - Winding in electric machine with stationary parts e.g. power transformer - Google Patents

Abstract

The winding is wound onto prefabricated drums (14,15) which are completely wound at the factory and then transported to the site where a transformer is to be used, where they are mounted on respective phases of the core. The winding consists of a high voltage cable which comprises a number of strands, an inner semiconductor layer surrounding the core, an insulating layer surrounding the inner semiconducting layer and an outer semiconducting layer surrounding the insulating layer. Preferably, the cable has a diameter in the range of 20-200mm and a conducting area in the range of 80-3000 mm2. Preferably, tubes or ducts for cooling the windings are arranged in the drums at manufacture before they are transported to the site where the transformer is to be used.

Description

10 15 20 25 30 35 511 161 2 The invention is primarily intended to be used and its benefits become particularly prominent with a high voltage cable of the type made up of a core with a plurality of strands, a core enclosing the inner semiconductor layer, an insulating layer of the inner semiconducting layer layer and an outer half enclosing the insulating layer. conductive layer. In particular, such a cable with a diameter is meant in the range 20 - 200 mm and a cable area in the range 80 - 3000 mmß. Such applications of the invention constitute thus preferred embodiments thereof.

The invention will now be described in more detail with reference to to the accompanying drawing, on which Fig. 1 shows a schematic section through a phase of a power transformer according to the invention and Fig. 2 shows a cross section through a tower according to the invention used winding cable.

Fig. 1 shows a part of a power transformer in section with a transformer core 11, a low voltage winding 12 and a high voltage winding 13. According to the invention the windings made on prefabricated drums 14 and 15.

These drums are pre-wound at the factory and then transported transported to the stand of the transformer, where they mounted on each phase of the core (in Fig. 1 is shown only a phase of the transformer).

In the example shown in Fig. 1, the high voltage winding 13 for manufacturing or transport reasons divided into two drums 15. When the winding is divided into several drums, tie the cables in the different windings on the mounting the site by means of a cable connection 16.

Fig. 2 shows a section through a power cable 1, used in a dry power transformer according to the invention.

The cable 1 comprises one consisting of a number of strands 2 conductors with a circular cross section and of, for example, copper.

This conductor is arranged in the middle of the cable 1. Around the conductor there is a first semiconducting layer 3. Around the first the semiconducting layer 3 has an insulating layer 4, e.g. PEX- insulation. Around the insulation layer 4 there is a second half 10 15 20 25 30 35 511 161 3 conductive layer 5. In this case, the cable thus does not include the outer protective sheath normally surrounding such a cable power distribution. The cable can be of the one specified in the preamble the order of magnitude.

For cooling the winding in the transformer according to the invention can be arranged pipes or ducts for cooling air between the winding cables. These pipes or ducts are suitably arranged in drums 14 and 15 during their manufacture before transport to the location of the transformer.

The invention provides a dry power transmission formator whose manufacture is simpler than in conventional transformers. Because the whole transformer does not need transported in its entirety from the factory to the space, both transport and assembly will be cheaper.

The invention is of course not limited to one power transformer but also applies to other electrical machines with fixed parts, such as inductive reactors.

Claims (8)

511 161 4 PATENT REQUIREMENTS Winding for an electric machine with fixed parts, which winding is in the form of ready-to-assemble drums (15), which drums (15) are intended to be mounted in the machine first at its installation site, characterized in that the winding (13) consists of high voltage cable (1). Winding according to Claim 1, characterized in that the high-voltage cable (1) consists of a core (2) with a plurality of strands, an inner semiconducting layer (3) enclosing the core (2), an insulating layer (4) enclosing the inner semiconducting layer. and an outer semiconductor layer (5) enclosing the insulating layer. Winding according to claim 2, characterized in that the high-voltage cable (1) has a diameter in the range 20 - 200 mm and a line area in the range 80 - 3000 mmz. Winding according to one of Claims 1 to 3, in which the machine consists of a power transformer with a core (11) and this enclosing low and high voltage windings (12, 13), characterized in that the windings (12, 13) are in the form of ready-to-assemble drums (14, 15) on which the cable (1) forming the windings (12, 13) is wound, Winding according to Claim 4, characterized in that the high-voltage winding (13) is divided into a number of drums (15) ° on each phase, cable connections (16) between the drums (15) being arranged during assembly on site. Winding according to Claim 1 or 2, characterized in that pipes or ducts for cooling the windings (12, 13) are arranged in the drums (14, 15) during their manufacture before transport to the location of the transformer. Power transformer, characterized by a winding according to one of claims 1 to 6. Inductive reactor, characterized by a winding according to one of Claims 1 to 3.