EP1529296B1 - Winding arrangement - Google Patents

Description

The invention relates to a winding arrangement with at least two windings arranged side by side in a row. From the U.S. Patent 4,318,066 For example, a transformer winding coaxially surrounded by a tubular electrostatic shield is known. The shield extends over the entire axial length of the winding and terminates with both winding end faces. Between the winding and the electrostatic shield three more tubular shields surrounding the winding are provided, which decrease stepwise from outside to inside in their axial length and complete all with the upper winding end face of the winding. There is also provided the connection of the winding. The variable in length electrostatic shields are intended to achieve a uniform voltage distribution along the winding at a pulse voltage stress of the winding; The electrostatic signs act as capacitors for voltage dissipation.

In the US 3,353,129 there is disclosed a winding arrangement with a low voltage winding wound around a transformer core. The low-voltage winding is surrounded by a high-voltage winding having concentrically extending winding planes, wherein the windings of the winding planes are wound on insulating elements. In addition, a shield is provided, which encloses both windings concentrically. The shield has, in addition to a supporting structure made of insulating material, inter alia, a conductive layer which is electrically connected to the high voltage side. At the two free ends of the shield forms tubular shields, which in axial Toward the outermost winding layer.

The US 3,039,042 discloses a transformer having primary and secondary windings and a shield for electrostatic shielding of the windings.

Other transformers with shielding are in the US 4,295,654 A as well as in the US 4,864,265 A described.

Winding arrangements with at least two windings arranged in series next to one another, as provided, for example, for inductors, may, for example, have a corresponding core, wherein each of the windings encloses a leg of the core, which are magnetically connected outside the windings with core yoke to form a closed circuit. Furthermore, it is customary to accommodate such a winding arrangement in a boiler formed with conductive walls and to fill the boiler with an insulating medium, for example cooling oil.

Also, such winding arrangements may be provided for transformers, wherein each of the two windings each forms a transformer winding of a respective transformer winding combination. The transformer windings formed with the windings are in each case assigned to a phase and an electrical side, for example the primary side of the transformer, wherein each of the transformer winding combinations has a second transformer winding, which forms the other electrical side of the corresponding phase.

In particular, in an application of the winding arrangement in a choke or a transformer for high-voltage DC transmission applications (HVDC) occurs in addition to an application of the windings with a harmonic-charged electrical AC voltage to a Gleichspannungsbeaufschlagung. Accordingly, the windings must be designed for the application of such harmonics or DC voltages. Accordingly, the windings are subjected before commissioning a corresponding AC and DC voltage test. In such a DC voltage test, the windings are one after the other or all acted upon together with a test DC voltage.

The object of the invention is to provide a winding arrangement which has a high electrical strength.

The object is provided with a winding arrangement with at least two windings arranged next to one another in a row, which are each surrounded by a barrier arrangement formed with an insulating material and each having a tubular electric shield in the area of each of the two Winding end faces of at least one of the windings, each shield surrounding the at least one winding coaxially leaving a gap and extending outwardly axially beyond the respective winding end face such that its axial height relative to the respective winding end face is equal to or greater than half of the radial Width of the gap is.

Characterized in that the windings are each surrounded by a formed with insulating barrier arrangement, is a high electrical insulation against a possibly existing core legs and also against a possibly existing boiler, which may have inside magnetic Kesselwandabschirmungen and in which the winding assembly is arranged, ie opposite outside the winding lying electrical parts, given. In addition, with the tubular electrical shields in the region of each winding end face, it is achieved that the electric field is guided there in such a way that the lowest possible electrical load on the barrier arrangement takes place there. Assuming that the barrier arrangement has at least one wall of insulating material surrounding the winding and in particular surrounds the radially outer, formed by the winding jacket surface and the winding end side winding edge on the winding end faces of a winding, so is achieved with the shields in particular in that the electric field strength which forms between the shield and the corresponding winding, in particular its winding edge, which occurs, for example, when the windings are subjected to direct voltage or direct voltage testing, stands substantially vertically on the surface of the wall of the barrier arrangement and emerges from it exit. So there are very few here tangential, ie along the surface of the wall of the barrier assembly directed electric field strength components. In the case of an embodiment without shields, in the case of such DC voltage application, in particular in the areas of the barrier arrangement in which the winding edges of the two adjacent windings lie close to each other, an electric field directed essentially in the axial direction is established. This has the effect that strong tangential electric field strengths directed along the surface of the wall of the barrier arrangement occur precisely in the region of the barrier arrangement adjacent to the outer winding edge, which can lead to an electrical fault. In the design of the signs with respect to the relative to the respective winding end face related height by which each shield exceeds the winding end face, it has been found that it is sufficient for a good field guidance, if this height is at least half the radial width of the intermediate gap. In that regard, the height must also increase correspondingly with increasing radial width of the intermediate gap. In particular, when using the winding arrangement according to the invention for a throttle, in which the two electrical windings are connected in parallel, the inventive design of the winding arrangement proves to be particularly advantageous. By providing the barrier arrangement and the electrostatic shields a particularly compact construction of the winding arrangement with the boiler is also possible, since the in particular at a DC voltage forming electrical fields - as described - out and evened outwards, whereby the probability of Rollover between one of the windings and arranged outside the windings electrically conductive parts is reduced to other potential. An electrically particularly safe winding arrangement results when all windings have in the region of their winding end faces such signs, as provided in the at least one winding.

In a preferred embodiment, the two electrical shields are formed together with a continuous, axially extending over the entire winding tubular overall shield. As a result, a corresponding shielding is achieved to the outside along the entire winding. This proves to be particularly advantageous in an arrangement of the winding arrangement according to the invention in a boiler, are provided for better magnetic field guidance outside the winding parallel to the core yokes aligned and arranged inside the boiler on the boiler wall magnetic core. In the case of winding arrangements without electrical shields, field strength increases which are usually formed in the case of the magnetic laminated cores can lead to flashovers between the winding and the magnetic laminated cores. By electrical signs of the electric field waveform between the winding and the boiler wall or the magnetic laminated cores is uniformed, whereby the risk of electrical flashover between the winding and the boiler wall is greatly reduced.

Preferably, the winding assembly forms a choke for high voltage direct current (HVDC) transmission systems. The winding arrangement according to the invention is particularly suitable for such a throttle.

According to another preferred embodiment, each of the two windings each forms an outer transformer winding of a respective transformer winding combination, wherein each transformer winding combination forms the outer transformer winding which coaxially surrounds an inner transformer winding. The two transformer windings are magnetically coupled and serve to transform an electrical phase, for example a polyphase electrical network.

The winding arrangement is preferably part of a transformer for HVDC systems. In such HVDC systems, the transformer may be exposed to a high DC voltage; Due to the inventive design, the winding arrangement is therefore particularly well suited for such a transformer.

The barrier arrangement can be designed, for embracing the outer winding edge, for example in such a way that the wall is formed with a tube of insulating material which radially surrounds the winding and projects beyond the winding end side, and with an insulating disk which closes the insulating material in a cover-like manner on each end face. In a preferred embodiment, each barrier arrangement in the region of the winding end faces in each case has at least one rounded outer angle ring, which surrounds the outer winding edge.

In a preferred embodiment, the shields each have a shield for field guidance in the region of their ends. With the shielding for field management high concentrations of electric field strength in the region of the ends of the shields are avoided.

Preferably, the winding assembly is disposed in a conductive vessel.

In the following, the winding arrangement according to the invention is explained in more detail with reference to the drawing.

• Figur 1 eine Schnittdarstellung einer Drossel mit der erfindungsgemäßen Wicklungsanordnung,
• Figur 2 einen Transformator mit der erfindungsgemäßen Wicklungsanordnung,
• Figur 3 einen Ausschnitt einer Wicklungsanordnung mit einer Abschirmung zur Feldführung in einer ersten Modifikation und
• Figur 4 einen Ausschnitt einer Wicklungsanordnung mit einer Abschirmung zur Feldführung in einer zweiten Modifikation.

Show it:

• FIG. 1 a sectional view of a throttle with the winding arrangement according to the invention,
• FIG. 2 a transformer with the winding arrangement according to the invention,
• FIG. 3 a section of a winding assembly with a shield for field guidance in a first modification and
• FIG. 4 a section of a winding arrangement with a shield for field guidance in a second modification.

In FIG. 1 is a winding assembly having two juxtaposed in a row windings 1 and 2, each extending along an axis 85 and 86, shown. The electrical connections of the windings 1 and 2 are for the sake of clarity in FIG. 1 omitted. Each of the windings 1 and 2 is surrounded by a respective barrier arrangement 3 or 4 formed of insulating material. Each of the barrier assemblies 3 and 4 has on each of the winding end faces 5, 6, 7 and 8 an outer angle ring 9, 10 and 11, 12, respectively. Likewise, at the winding end faces 5, 6 and 7, 8, an inner angle ring 13, 14 and 15, 16 are provided. The outer angle rings 9, 10 and 11, 12 each encompass the winding outer surface 5, 6 and 7 or 8 formed with the winding jacket surface 17 and 18 and the adjacent, radially outer winding edge 19 and 20 and. 21 or 22. The inner angle rings 13, 14 and 15, 16 respectively engage around a radially inner winding edge 19A, 20A and 21A, 22A.

For shielding present in both windings 1 and 2 in the areas of their winding end faces 5, 6 and 7, 8, the tubular overall shields 23 and 24 are provided. The overall shields 23 and 24 surround the windings 1 and 2, leaving a gap 23A and 24A and are hinged to ground potential, d. H. Connected to earth potential via a connection. In the present case, the overall shields 23 and 24 each extend over the entire axial length of the associated windings 1 and 2 and on the winding end faces 5, 6 and 7, 8 beyond the winding end faces, in such a way that - as exemplified in the overall shield 23 - The axial, relative to the winding end face 5 related height B is more than half the radial width A of the intermediate gap 23A.

Considering, for example, the winding edge 19, it is particularly well with the outer angle ring 9 electrically opposite outside of the winding 1 arranged conductive parts - such. B. the core 25, the boiler 26 or arranged in the boiler 26 on the wall 27 of the magnetic laminated core 28 - isolated. With the overall shield 23, it is additionally achieved in this area that the electric field originating from the winding end face 5 and the winding jacket surface 17 in the region of the winding edge 19, which is established during operation or during a DC voltage test, is guided on the surfaces 29 and 30 of the outer angle ring 9 is almost vertical and ends on the plate 23. In that regard, as a result, the electrical load on the barrier assembly 3 in the region of the winding edge 19 when exposed to a DC voltage during operation or in a DC voltage test low.

If the overall shields 23 and 24 were not present, an electric field would result, in particular in the case of direct-current loading of the windings 1 and 2 in the region of the winding edges 19 and 21 which are very close to each other, ie in the core window 31 of the core 25, which extends substantially in the axial direction, that is no longer perpendicular to the surfaces 29 and 39 of the outer angle ring 9 and the corresponding surfaces of the outer angle ring 11 is. This would lead to a strong electrical stress along the surface 29 or 30, in particular in the region close to the winding edge 19, which can lead to an electrical fault.

The barrier assemblies 3 and 4 with their outer angle rings 9, 10, 11 and 12 and the inner angle rings 13, 14, 15 and 16 are formed in particular from Presspan.

The transformer tank 26 may be filled with an insulating medium such as cooling oil.

In addition, it is also possible to omit the overall shield 24. Likewise, the core 25 can be omitted, so that there is a coreless throttle.

In FIG. 2 is a sectional view through a provided for a two-phase transformer winding arrangement shown.

There are two transformer winding combinations 32 and 33, each extending along an axis 87 and 88, respectively, with the transformer winding combination 32 having an outer transformer winding 34 and an inner transformer winding 35 and the second transformer winding combination 33 has an outer transformer winding 37 and an inner transformer winding 36. The respective outer transformer windings 34 and 37 surround the respective inner transformer windings 35 and 36 coaxially. Again, the electrical connections of the transformer windings 34, 35, 36 and 37 are not shown for clarity. Each of the transformer windings 34, 35, 36, 37 is surrounded by a barrier arrangement 38, 39, 40, 41 assigned to it. Each of the barrier assemblies 38, 39, 40, 41 faces the outer angle rings 9, 10, 11, and 12, respectively FIG. 1 Comparable outer angle rings 42, 43, 44, 45, 46, 47, 48 and 49 and to the inner angle rings 13,14, 15 and 16 according to FIG. 1 comparable inner angle rings 50, 51, 52, 53, 54, 55, 56, 57 on.

In the region of the winding end faces 58, 59, 60 and 61 of the outer transformer windings 34 and 37 tubular, the transformer windings 34 and 37 surrounding electrical shields 62, 63 and 64 and 65 are provided. The electrical shields 62, 63, 64 and 65 surround their respective windings forming a respective intermediate gap 62A, 63A, 64A and 65A, respectively. Compared to the winding arrangement according to FIG. 1 Here, for example, instead of the overall shield 23, the two individual shields 62 and 63 are provided which each extend over only a part of the axial length of the transformer winding 34. In other words, the overall shields 23 and 24 each combine the function of the two shields 62 and 63 or 64 and 65. The shields 62, 63, 64 and 65 extend in the axial direction over the respective winding end face 58, 59, 60 and 61 such that - as explained in the example of the shield 62 - their respective axial relative to the winding end face 58, 59, 60, 61 related Height D is at least equal to half the radial width C of the intermediate gap 62A.

The winding arrangement according to FIG. 2 is disposed within a transformer tank 66. Each of the transformer winding combinations 32 and 33 surrounds a core leg 67 and 68, respectively, of a transformer core 69; the core legs 67 and 68 are magnetically connected via core yokes 70 and 71 to form a closed magnetic circuit. On the inner sides 72 and 73 of the transformer armature 66, magnetic-laminated cores 74 and 75 are provided for better magnetic field guidance.

In this arrangement too, the barrier arrangements 38 to 41 may be formed of pressboard, and the transformer tank 66 may also be filled with an insulating medium, for example cooling oil.

The electric shields 62, 63, 64 and 65 have the same function as the overall screens 23 and 24 according to FIG FIG. 1 namely, in particular in the core window 76 of the transformer core 69 to guide the electric field so that it passes tangentially through the outer angle rings 46 and 42 or 43 and 47 and a small electrical load of the barrier assembly 38 and 40 occurs.

Instead of the total screens 23 and 24 according to FIG. 1 can there also the in FIG. 2 Shields 62 to 64 shown may be provided.

Conversely, the shields 62 and 63 and / or 64 and 65 according to FIG. 2 in the winding arrangement according to FIG. 2 each by corresponding axially continuous overall screens, as in FIG. 1 shown to be replaced. The shields 62 and 63 are then together, so in one piece, formed with a continuous, extending axially over the entire winding overall shield; The same applies to the shields 64 and 65. In addition, the transformer core 69 can also be omitted here. The shields 64 and 65 can also be omitted in this embodiment, the shields 62 and 63 are sufficient for shielding; However, in order to achieve a particularly good shielding, 58 to 60 shields 62, 63, 64 and 65 are provided in the region of all winding end faces.

Also, the barrier arrangements 3, 4 according to FIGS. 1 and 38 to 41 according to Fig. 2 be formed with multiple layers, ie with multiple outer angle rings and inner angle rings.

The shields 62 to 65 and 84 and the overall shields 23 and 24 may have in the region of their ends shields for field guidance, as in the FIGS. 3 and 4 each shown.

In FIG. 3 a section in the region of a winding end side 79 of a winding 77 lying cutout is shown. The winding 77 extends along an axis 78 and is surrounded by an intermediate gap 80 surrounded by a shield 81, which is representative of the shields 62 to 65 or the overall shields 23 and 24 can be seen. In the region of its end 82, the shield 81 has a shield 83 for field guidance. This surrounds the axis 78 and extends in the circumferential direction of the shield 81 along the end 82. The shield has two conductive wires 84 and 84 A, which are each electrically insulated with a corresponding insulation 89 and 89 A and together with a total insulation 90. The two conductive wires 84 and 84A are connected to ground potential. The two wires 84 and 85 are along their Length along the circumference of the shield 81 interrupted at least once, so that there is no closed turn. The shield 83 serves to avoid field elevations or high field concentrations in the region of the end 82 of the screen 81.

In FIG. 4 a modified shield 91 for field guidance is shown; it has in comparison to the shield 93 after FIG. 3 a single conductive wire 92 surrounded by electrical insulation 93. The wire 92 is also connected to earth potential and interrupted along its length along the circumference of the shield 81 at least once, so that there is no closed turn.

The shields 83 and 91 are to ensure that no field peaks occur at the end 82 of the shield 81. They can also be designed as an electrical conductive tube, for example with a circular or elliptical cross section, running around the axis 78 along the end of the shield 81. Likewise, instead of a tube, a conductive foil may be provided on a correspondingly shaped carrier body. Also, the shields 83 and 91 can be formed with the shield 81 itself by the shield 81 is bent so that a rounded brim is formed, or it can also be bent so far that the bent part gives a kind of circumferential tube.

The shields 62 to 65 and the overall shields 23 and 24 may each have a shield 83 or 91 for field guidance in the region at their ends.

Claims (9)

1. Winding arrangement having at least two windings (1, 2, 34, 37), which are arranged next to one another in a row and each of which is surrounded by a barrier arrangement (3, 4, 38, 40) formed exclusively of insulating material, and each having a tubular electric shield (23, 62, 63) in the region of each of the two winding end sides (5, 6, 58, 59) of at least one of the windings (1, 34), each shield (23, 62, 63) coaxially surrounding the at least one winding (1, 34) leaving an intermediate gap (23A, 62A, 63A) and extending axially outwards beyond the respective winding end side (5, 6, 58, 59) such that its axial height (B, D), in relation to the respective winding end side (5, 6, 58, 59), is equal to or greater than half the radial width (A, C) of the intermediate gap (23A, 62A, 63A).
2. Winding arrangement according to Claim 1,
   characterized in that
   the two electric shields are formed jointly with a continuous, tubular, joint shield (23, 24) which extends axially over the entire winding (1, 2).
3. Winding arrangement according to Claim 1 or 2,
   which forms an inductor for high-voltage DC transmission systems.
4. Winding arrangement according to Claim 1 or 2,
   characterized in that each of the two windings (34; 37) forms a respective external transformer winding (34; 37) of a respective transformer winding combination (32; 33), each transformer winding combination (32; 33) having the external transformer winding (34; 37) which coaxially surrounds an internal transformer winding (35; 36).
5. Winding arrangement according to Claim 4, which is part of a transformer for high-voltage DC transmission systems.
6. Winding arrangement according to one of the preceding claims,
   characterized in that,
   in the region of the respective winding end side (5, 6; 7, 8; 58, 59; 60, 61), the barrier arrangement (3, 4; 38, 40) has in each case at least one outer flange ring (9-12; 42, 43, 46, 47) which engages around the radially outer winding edge (19-21).
7. Winding arrangement according to one of the preceding claims,
   characterized in that
   the shields (62-64; 23, 24) each have a screen (83, 91) for field guidance purposes in the region of their ends.
8. Winding arrangement according to one of the preceding claims, which is arranged in a conductive tank (26, 66).
9. Winding arrangement according to one of the preceding claims, characterized in that the windings (1, 2; 34, 37, 35, 36) each surround a core limb (67; 68) of a transformer core (25, 69).

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