ELECTRICAL DEVICE HAVING A TANK WITH A CONVEX BULGING PORTION

Abstract

An electrical device for connection to a high-voltage system has a tank filled with insulating fluid. The tank has at least one side wall forming a planar wall portion and a radially outwardly curved bulging/convex portion, which increases the interior volume of the tank. An active part with a core and at least one winding is arranged in the tank. A winding barrier system encloses one or more windings. The convex bulging portion has a shape that complements a portion of the winding barrier system and lies opposite it at a distance, such that the electrical device has increased dielectric strength. An additional barrier is disposed between the winding barrier system and the convex bulging portion which has a round portion, bent radially outwards and facing the convex bulging portion, and two planar flat portions, which at an axial crease respectively extend out of the round portion towards a free end.

Claims

1-10 (canceled)

11. An electrical device for connection to a high-voltage system, the electrical device comprising: a tank filled with insulating fluid, said tank having at least one side wall with a planar wall portion and a radially outwardly curved convex bulging portion, which extends between two axial edges and increases an interior volume of said tank; an active part disposed in said tank, said active part having a core and at least one winding enclosing a portion of said core; at least one winding barrier system enclosing one or more of said windings; said convex bulging portion having a shape that complements a portion of said winding barrier system and lies opposite said winding barrier system at a spacing distance; and an additional barrier between said winding barrier system and said convex bulging portion, said additional barrier having a round portion facing toward said convex bulging portion and being bent radially outwards, and two planar flat portions respectively extending via an axial crease from said round portion toward a free end.

12. The electrical device according to claim 11, wherein said round portion is formed with a shape that complements the convex bulging portion.

13. The electrical device according to claim 11, wherein each of said flat portions extends parallel to said planar wall portion of said side wall.

14. The electrical device according to claim 11, wherein said additional barrier is supported by way of at least one lid segment arranged at a spacing distance from said winding barrier system and by way of a support band at a spacing distance from said winding barrier system and said convex bulging portion.

15. The electrical device according to claim 11, further comprising at least one adjuster, which extends between said winding barrier system and said flat portion of said additional barrier.

16. The electrical device according to claim 15, wherein said at least one adjuster is secured to said winding barrier system by way of said support band.

17. The electrical device according to claim 15, wherein said at least one adjuster is secured to the respective said flat portion by a securing line.

18. The electrical device according to claim 11, wherein said winding barrier system has a circular-cylindrical outer contour and said convex bulging portion delimits a portion of a circular hollow cylinder, and wherein said winding barrier system and said convex bulging portion are arranged concentrically with respect to one another.

19. The electrical device according to claim 11, wherein said convex bulging portion and said round portion each delimit a portion of a respective hollow cylinder, wherein the hollow cylinders have different radii and said convex bulging portion and said round portion are arranged concentrically with respect to one another.

20. The electrical device according to claim 19, wherein, in a plan view, said two axial edges of said side wall and said two creases of said additional barrier span the same angle with respect to a center point.

Description

[0019] Further expedient configurations and advantages of the invention are the subject of the following description of exemplary embodiments of the invention with reference to the figures of the drawings, wherein the same reference signs refer to components with the same effect and wherein

[0020] FIG. 1 shows a sectional plan view of an electrical device according to the prior art,

[0021] FIG. 2 shows an exemplary embodiment of the electrical device according to the invention in a sectional plan view,

[0022] FIG. 3 shows the securing of the additional barrier to the winding barrier system and

[0023] FIG. 4 shows the securing of the lid segment and the segments of the winding barrier system in a perspective view.

[0024] FIG. 1 shows an exemplary embodiment of an electrical device 1 according to the prior art in a cut-away cross-sectional view from above. The electrical device 1 shown is embodied as a power transformer 1, which has a tank filled with an insulating fluid, of which only one side wall 2 can be seen. The side wall 2 has a flat wall section 3 and a radially outwardly curved convex bulging portion 4, which increases an interior volume of the tank. The convex bulging portion is arranged between two axial edges 5 and 6 that extend in an axial direction. In FIG. 4, the axial direction goes into the plane of the drawing or comes out of the plane of the drawing.

[0025] Inside the tank, which is illustrated only partly by way of the side wall 2 thereof, a high-voltage winding 7 and a low-voltage winding 8 are arranged, these being arranged concentrically with respect one another and with respect to a core limb that is not illustrated in the figures.

[0026] It can be seen that the convex bulging portion 4 is outwardly curved in a manner that increases the internal volume of the tank such that a required minimum distance remains between the high-voltage winding 7 and the side wall 2 and high electrical field strengths with voltage flashovers are prevented within the transformer 1. As has already been stated further above in the description, however, high electrical field strengths can occur at the edges, which are illustrated as corners in the sectional view shown, such that the operating voltage of the power transformer cannot be further increased without voltage flashovers occurring at said corners or splays; these voltage flashovers would irreparably damage the electrical device.

[0027] FIG. 2 shows an exemplary embodiment of the electrical device 9 according to the invention, which is again embodied as a transformer 9. The transformer 9, illustrated only partly in a sectional plan view, has a tank, of which only one side wall 2 is illustrated in FIG. 2, which again has a flat wall section 3 and a radially outwardly curved convex bulging portion 4. In this case, the old charging/convex portion 4 extends between edges 5 and 6 that extend in the axial direction, these being illustrated as corners 5 and 6 in FIG. 2 due to the selected sectional illustration.

[0028] The transformer 9 is filled with an insulating fluid, for example a mineral oil or an ester liquid. Arranged in the interior of said transformer is a magnetizable core, of which only one core limb 10 can be seen in FIG. 2. The core limb 10 is surrounded concentrically by a low-voltage winding 8 and a high-voltage winding 7. The two windings 7 and 8 are enclosed in turn by a barrier system 11, which consists of individual barriers 12 that are radially spaced apart from one another. Oil channels, which increase the electric strength of the transformer 9, are formed between the barriers 12 of the barrier system 11.

[0029] Furthermore, it is possible to identify an additional barrier 13, which has a round portion 14, which faces the convex bulging portion 4 and from which two flat portions 15 and 16 each extend towards a free end. The round portion 14 is formed with a shape that complements the circular-cylindrical outer contour of the winding barrier system 11 and with a shape that complements the convex bulging portion 4 of the side wall 2. The flat portions 15 and 16 extends substantially parallel to the planar wall portions 3 of the side wall 2. In other words, the flat portions 15 and 16 extend from the axial creases 17 and 18, which are again illustrated as corners in FIG. 2 due to the two-dimensional illustration.

[0030] In the exemplary embodiment shown in FIG. 2, the round portion 14 transitions in each case into one of the flat portions 15 and 16 at said axial creases 17 and 18. In other words, the additional barrier 13 is formed in one piece. In the exemplary embodiment illustrated, it consists of pressboard, like the barriers 12 of the winding barrier system 11. However, in a deviation therefrom, other electrically non-conductive materials can also be used to produce the additional barrier. For example, the additional barrier consists of cardboard, paper or also even of an electrically non-conductive plastic.

[0031] FIG. 3 shows the securing of the additional barrier 13 in more detail. It can be seen that lid segments 19 are used to keep said additional barrier at a distance from the outer barrier 12 of the winding barrier system 11. The lid segments 19, which are also round in design, are formed in an L-shaped manner in a longitudinal sectional view and are clamped to a lower securing system 20 at the shorter lower end thereof. The securing system 20 is also used to secure the barriers 12 of the winding barrier system 11 and in this case is arranged on the bottom of the tank. Longitudinal slots, through which a respective flat portion 16 of the additional barrier 13 extends, are formed between two lid segments 19 that are arranged next one another.

[0032] In addition to the lid segments, provision is made of a support band 21, which consists of cardboard and is embodied as a flat band. The support band lies by way of its flat side on the outer contour of the winding barrier system 11 and from there is led through a slot 22 in the round portion 14 of the additional barrier 13 such that the support band 21 surrounds the round portion from the outside and thus ensures additional support of the additional barrier 13.

[0033] Furthermore, it is possible to identify a spacer or adjuster 22, which has a bent lower-end portion 23 by way of which it lies on the outer contour of the winding barrier system 11. The support band is led via the lower-end portion such that the lower-end portion 23 is pressed against the winding barrier system 11 by the support band 21. An adjuster slot 24, through which the support band 21 is led, is formed in the lower region of the adjuster 22.

[0034] Provided on the end of the adjuster 22 facing away from the lower-end portion 23 are clearance holes, which are arranged flush with the clearance holes in the flat portion 16 of the additional barrier 13. A securing line 25 made of paper is led through the clearance holes of the adjuster 22 and the clearance holes of the flat portion 16 such that the adjuster 22 is secured to the flat portion 16. In the context of the invention, the securing line can also be made from another electrically non-conductive material. The adjuster 22 is formed so as to be dimensionally stable such that it ensures fixed and stable orientation of the flat portions 16 with respect to the flat wall sections.

[0035] FIG. 4 illustrates the securing of the lid segments 19 to the securing system 20. It is possible to identify in particular the configuration of the lid segments 19 in an L-shaped manner in longitudinal section. It is also possible to identify the inner barriers 12 of the winding barrier system 11 due to a partly transparent illustration.