SE426116B - POWER TRANSFORMER OR REACTOR - Google Patents

Description

According to the invention, the conductor is composed of relatively few, preferably only two, two conductors. These are not transposed within any winding disk and essentially retain their respective relative positions during buckling and other similar shape changes. A disk winding according to the invention contains for the most part winding disks in which each turn is formed by sub-conductors which are arranged next to each other in the horizontal direction. These winding disks are arranged in the part of the winding body where the leakage flow runs mainly vertically, ie parallel to the transformer leg. In addition, the winding body contains at least one winding disk which is arranged in an end portion of the winding body and which contains a plurality of winding turns of a conductor, the sub-conductors of which are arranged one above the other. Since the leakage flow at the ends of the winding body is rather horizontally directed, it is thus achieved that the flow also in the end points (s) of the winding runs substantially parallel to the insulation layers existing between adjacent sub-conductors, which generally means that a division of the conductor into a plurality of sub-conductors a significant reduction in the addition losses of the winding.

The various discs of the winding are connected in series, whereby a plurality is formed, for example two groups of sub-conductors connected in series in the case of a double-wound laser cross section.

These groups ü are connected in parallel by being connected in the winding. A division of the conductor into a plurality of sub-conductors usually results in reduced buckling strength of a transformer winding and thus less ability to withstand short-circuit forces.

According to a further development of the invention, the parts are glued to each other. in such a way that the division of the conductor into sub-conductors does not entail any appreciable deterioration of the mechanical properties of the winding.

Each sub-section can then be completely surrounded by sub-section insulation. Preferably, however, the insulation between adjacent sub-conductors is provided only in the form of an insulating layer arranged between them. By allowing this layer to be formed to a greater or lesser extent by a binder, the above-mentioned gluing of sub-conductors can be achieved in a winding according to the invention. The insulation surrounding the conductor may be of a conventional type and consist of a spiral thread, with overlapping wound tape of cellulosic paper or of polymer film, such as a film of polyethylene glycol terephthalate, polycarbonate, in i._.._ .., 8102746-8 polyimide, polyamidimide, polypropylene, polymethylpentene or polysulfone. The insulation can also last, among other things. of a wrapping of a yarn of any of the said materials.

As an example of. Suitable materials for the material which can be heated to form the adhesive joint are hardenable resins such as epoxy resins, polysmide-modified epoxy resins, urethane resins, isoyanate-modified ester resins, urethane-resin-modified epoxy resins and some adhesives. from Du Pont, USA) and thermoplastic resins (hot melt adhesives) such as polyethylene glycol terephthalate, polyamide and polycarbonate. The adhesive-forming material can advantageously be arranged in the form of a separate film between the conductor parts. It is also possible to apply the material in the form of a layer arranged on at least one of the two flat sides of the conductor parts facing each other by coating one of the conductor parts t e: with a solution of the material. The adhesive joint is only achieved after a winding has been made by the conductor, ie the conductor has been given its final shape, and thereby preferably in connection with the winding being dried, whereby it is heated sufficiently for the adhesive joint-forming material to provide a joint between the conductor parts. On. due to the fact that the outer conductor part of the conductor is stretched relative to the inner conductor part during the winding work, the insulating layer is subjected to a radial pressure, which favorably affects the production of a mechanically strong joint.

The spacer element of insulating material in the material forming the adhesive joint has the task of ensuring that the conductor parts are held on. distance from each other and do not make contact with each other, especially when gluing when the material for the glue joint is liquid or soft. Although the conductor term terminals are interconnected at the ends of the winding, the magnetic flux in them becomes somewhat different. that a voltage arises between them in operation, so an insulation is required between them. Suitable dispersing elements are paper, blankets or webs of fibrous material, such as cellulose fibers, polyethylene glycol terephthalate, polyamide, polyvinyl acetate, polyalyl nitrile, polypropylene and glass. In paper or blankets, the fibers may be bound. to each other, for example by mechanical means by felting, or by melting or with an adhesive. The spacer element can be solid or provided with through pores or holes, which are filled with adhesive joint-forming material. Used paper, blankets or fabrics can be sparse. It is also possible to use as spacer elements conventional powdered fillers, such as powders of lime, glitter, quartz or alumina, or conventional fibrous fillers, such as fibers of cellulose, glass or other for paper, blankets and woven fabrics: fiber materials exemplified above. The invention will be explained in more detail by describing a power trans; The apparatus according to the invention with reference to the accompanying schematic drawings, in which Figs. sig 2 more hm. the transformer, while Fig. 5 shows the windings on a larger scale. Fig. 4A and Fig. 43 show a partial vertical section through the high voltage winding at a middle portion and an end portion, respectively. The low-voltage winding is designed as a bearing winding and the high-voltage winding as a disk winding. Pig 1G shows in cross section an alternative embodiment of the on. Fig. 115 »showed the conductor.

Fig. 5 shows in a perspective view a disc winding as carried out according to the invention and in substantially the same manner as that on. Fig. 3 shown. Fig. 6 illustrates an interconnection principle, which in a winding according to the invention gives an even current distribution between the sub-conductors.

In Fig. 1A are two. sub-conductors denoted 10 and 11, respectively. In accordance with Figs. Each conductor part has a thickness of 2 mm 'and a width of. wicker side of 12 mm. An insulating layer 12 is arranged between the flat sides.

This. is made up of a curable resin and a 0.15 mm thick and 12 mm wide spacer element 13 in the form of a sparse and very fibrous felt, which consists of a mixture of polyvizylacetate fiber and polyamide fiber bonded with an elcoylate binder and having a basis weight of 30 g / me (such as Non-woven Storalen 670-50 from Stora Kopparbergs LB). The curable. The bertset with which the spacer element is impregnated consists of an epoxy resin (such as Araldit B from Ciba, Switzerland) provided with dioyandiamide as a hardener, using 3 parts by weight harder per 100 parts by weight of epoxy resin. The insulating layer, which is tack-free, is arranged loosely between the conductor parts as a separate band. and is thus not glued to the joint parts. The conductor parts 10 and 11 and the insulating layer 12 together form the conductor 8. The conductor is surrounded by a wrap 217 of helical paper tape.

In the transformer, 41 denotes a high voltage bushing, 42 a low voltage bushing, 43 the transformer box, 44 a press flange, 45 an insulated support for the low voltage connection 46, 47 spacers etc., 48 the low voltage winding, 49 the high voltage winding, 50 a vertical leg of the transformer. 48 ooh 49, 51 inserts of press pan and 53 insulating cylinders of press pan.

The high-voltage winding 49 is designed as a disk winding with a plurality of winding disks arranged in each horizontal plane, of which the two uppermost ___... ...___..., _..._.-._ í ...._. hd- __ _> 15 25 8102746-8 and the bottom two are denoted by 60, while the other winding discs. i are denoted by 61. The winding disks 61 are made according to fi; 1A and Fig. 4A, while the winding disks 60 are made according to Figs. 13 and Fig. 43. Each ooh of the winding disks 61 contains a plurality of turns of a conductor 8 arranged in an ooh and the same horizontal plane, comprising the two. sub-conductors 10 and 11 and a vertically dry insulating layer 12 arranged therebetween.

In an upper and a lower part of the winding 49, the leakage flow passing through the winding has a substantially horizontal course, so that the winding disks 60 are wound by a conductor 8 'which is divided into two sub-conductors 10' and 11 ', which are insulated from each other by means of a layer 12 ', which lies in one in a horizontal plane, but which is otherwise made in the same way as on. Fig. 1A shows the layer 12. Layer 12 'contains spacers 13' of the same material as the spacers 13. The conductor 8 'is provided with conductor insulation 17' of the same type as the conductor insulation 17.

Alternatively, the discs can. 60 lindss of a leader who is heaped by two. sub-conductors 10 "and 11", each of which is enclosed by sub-insulator and preferably glued to each other.

From: Big 6 it appears that a disk winding, the end disks of which are made according to Fig. 13, i.e. with the sub-conductor 10 'at the top and the sub-conductor 11' at the bottom of each conductor at both ends of the winding lcropy, has an even current distribution between the two sub-conductors. containing all sub-conductors 10 'has the same relation to the leakage flow overall as an eerie group containing all sub-conductors 11'.

The curable resin in the insulating layers 12 and 12 'cures and forms a mechanically strong adhesive joint between the conductor parts when the winding is dried at about 130% for about 12 hours.

After drying, the transformer box 45 is completely filled with transformer oil.

Claims (3)

s 8102746-8 PÅTEHIKRAV A power transformer or reactor comprising a core made of magnetic material with a yoke and having at least one leg (50) arranged with a vertical longitudinal axis, which is enclosed by a winding body (49), which contains a plurality, vertically arranged one after the other and interconnected winding discs (60, 61), while each disc. contains a plurality of turns of a conductor (8, 8 ') which is composed of at least two mutually insulated sub-conductors, characterized in that at least one in said winding: - body included and at one end thereof. arranged winding coil (60) contains a plurality of winding turns, each of which contains a plurality of 6 sub-conductors (10 ', 11') arranged only in their respective horizontal planes, while the others of the winding body. Winding coils (61) are wound by conductors (8) joined by a plurality of horizontally adjacent sub-conductors (10, 11). 2. A power transformer or reactor according to claim 1, characterized in that said sub-conductors (10 ', 11') arranged in different horizontal planes are glued together. * 3. A power transformer or reactor according to claim 1, characterized in that said winding body comprises an upper winding disk (60) arranged at the top of the winding cup and a lower winding lever (60) arranged at the bottom of the winding body. ), which each contain an upper (1o ~) een a neare (w) aeueme, var-via the upper dans-en (1o ') 1 nämen öm nnaningsskim av eeriekoppnea maa den övre aeneamn (1o') i said lower delekiva.