Winding assembly

Abstract

A winding assembly for a transformer, in particular with a medium operating voltage of Um≥79.5 kV, wherein the winding assembly includes at least one winding, which ends in a winding conductor, where the winding conductor is connected to a switching line, which is configured to interconnect the winding to other windings, and where the connection of the switching line to the winding conductor is arranged inside the winding so as to reduce the danger of partial discharges and flashovers in the high-voltage end-line region for high-temperature applications.

Claims

1. A winding assembly for a transformer having a medium operating voltage of Um≥72.5 kV, comprising: a winding conductor; at least one winding which ends in the winding conductor, the winding conductor being connected to a switching line which is configured to connect the winding to other windings; and a connecting element which establishes the connection between the switching line and the winding conductor, the connecting element being surrounded by an electrical shielding; wherein the connection of the switching line to the winding conductor is arranged inside the winding; wherein the electrical shielding also surrounds a part of the winding conductor adjoining the connecting element and a part of the switching line adjoining the connecting element; and wherein the electrical shielding, the part of the winding conductor adjoining the connecting element and the part of the switching line adjoining the connecting element are surrounded by a common insulation.

2. The winding assembly as claimed in claim 1, wherein the connection between the switching line and the winding conductor is a crimp connection.

3. The winding assembly as claimed in claim 1, wherein the electrical shielding comprises a conductive layer which at least surrounds the connecting element.

4. The winding assembly as claimed in claim 1, wherein part of the at least one winding is still located both radially outside a connection of the switching line to the winding conductor and also axially before and after this connection of the switching line to the winding conductor.

5. The winding assembly as claimed in claim 1, wherein part of the at least one winding is still located both radially inside a connection of the switching line to the winding conductor and also axially before and after this connection of the switching line to the winding conductor.

6. The winding assembly as claimed in claim 1, wherein part of the winding is still located radially inside, radially outside, axially before and axially after a connection of the switching line to the winding conductor.

7. A transformer having the winding assembly as claimed in claim 1.

8. The transformer as claimed in claim 7, wherein the transformer is a power transformer.

9. The transformer as claimed in claim 8, wherein the power transformer is an oil-filled distribution transformer.

10. A winding assembly for a transformer having a medium operating voltage of Um≥72.5 kV, comprising: a winding conductor; at least one winding which ends in the winding conductor, the winding conductor being connected to a switching line which is configured to connect the winding to other windings; and a connecting element which establishes the connection between the switching line and the winding conductor, the connecting element being surrounded by an electrical shielding; wherein the connection of the switching line to the winding conductor is arranged inside the winding; wherein the electrical shielding comprises a conductive layer which at least surrounds the connecting element; and wherein the electrical shielding, the part of the winding conductor adjoining the connecting element and the part of the switching line adjoining the connecting element are surrounded by a common insulation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) To further explain the invention, reference is made in the following part of the description to the figures, from which further advantageous details and possible areas of application of the invention can be seen. The figures are to be understood as examples and are intended to set out the nature of the invention, but in no way narrow it down or even reproduce it conclusively, in which:

(2) FIG. 1 is a longitudinal cross-sectional illustration of the winding assembly in the region of the connection between switching line and winding conductor in accordance with the invention; and

(3) FIG. 2 is a longitudinal cross-sectional illustration of the region around the connection between the switching line and winding conductor of FIG. 1.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

(4) FIG. 1 shows the upper end of an inventive winding assembly with a winding 1, which is arranged around a winding axis 5. Further windings can be arranged radially inside and/or outside the winding 1. The winding 1 is generally wound around a core leg (not shown), of a transformer core and consists of one or more winding conductors 3. The winding conductor 3 can, for example, be a winding wire. In order to conduct the electrical energy out of the winding 1 and then out of the transformer housing that surrounds the windings 1, or to introduce the electrical energy from outside through the transformer housing into the winding 1, an “end lead” is provided, in other words a conductive connection that connects the end of the winding conductor 3 of the winding 1 through the transformer housing to a line outside the transformer.

(5) The end lead also comprises “switching lines” 2, via which the individual windings 1 of the transformer can still be interconnected inside the transformer housing. In this way, the three phases of a three-phase AC transformer can be interconnected.

(6) The winding 1 ends in a winding conductor 3 and is connected via a connecting element 4 to a switching line 2 that is used to connect the winding 1 to other windings. The connecting element 4 is arranged inside the winding. On the one hand, this means that in the radial direction of the winding 1, i.e., at right angles to the winding axis 5, a part of the winding 1 is still located at least outside the connecting element 4, here the majority of the winding 1. The end of the winding conductor 3 here forms the start of the winding 1, which is formed here as a high-side voltage winding. The start of the winding and thus the connecting element 4 lies here—viewed in the radial direction—on the inside of the insulation of the winding 1 to the main scattering gap, and this in turn lies between the high-side voltage winding and the low-voltage winding.

(7) Inside the winding also means that a part of the winding 1 is still located in the direction parallel to the winding axis 5 before and after the connecting element 4. In FIG. 1, there are thus also further winding conductors of the winding 1 above and below the connecting element 4. These further winding conductors of the winding 1 therefore insulate the connecting element 4 from the space outside the winding 1.

(8) The arrangement of the connection, i.e., the connecting element 4 here, corresponds in FIG. 1 to the previously described first embodiment for the start of the winding. However, in accordance with the second embodiment, the connecting element 4 could also be used for the end of the winding which, viewed in the radial direction of the winding 1, lies on the outside, see the alternative position 9 of the connecting element 4, drawn in as a perpendicular line. The connecting element 4 would then be radially outside, for example, only surrounded by the insulation of the winding 1, on all other sides (radially inside, axially) by the winding conductors of the winding 1. However, in accordance with the third embodiment, the connecting element 4 could also be used for a tap which, viewed in the radial direction of the winding 1, lies at any point between the start and end of the winding, see the exemplary alternative position 8 of the connecting element 4, drawn in as a perpendicular line. The connecting element 4 would then be surrounded on all sides by winding conductors of the winding 1.

(9) Because the switching line 2 has a larger conductor cross-section than the winding conductor 3, the electrical field strength on the outside of the switching line 2 outside the winding 2 is lower than in the case of the winding conductor 3, if this were to be led out of winding 1—in FIG. 1 above out of the winding 1—instead of the switching line 2.

(10) In FIG. 2 the connecting element and—partially in section—its immediate surroundings are shown enlarged. Both the switching line 2 and the winding conductor 3, which has a smaller cross-section than the switching line 2, are guided into the connecting element 4 and mechanically and electrically conductively connected to one another therein via a crimp connection. An electrical shielding 6 surrounds the connecting element 4, the part of the winding conductor 3 adjoining the connecting element 4 and the part of the switching line 2 adjoining the connecting element 4. In this region—seen in the direction parallel to the winding axis 5 (see FIG. 1)—and beyond an insulation 7 is provided that surrounds the electrical shielding 6, the part of the winding conductor 3 adjoining the connecting element 4 and the part of the switching line 2 adjoining the connecting element 4.

(11) Thus, while there have been shown, described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.