Electrical device with raised container

Abstract

An electrical device (9) for connection to a high-voltage power network, having a container filled with an insulating fluid, which container has at least one side wall (2) which forms a flat wall section (3) and a radially outwardly curved, convex section (4) which enlarges the inner volume of the container, which convex section extends between two axial edges (5, 6), and having an active component arranged in the container, which active component has a core (10) and at least one winding (7, 8) which surrounds a section of the core (10), and at least one winding barrier system (11) which surrounds one or more windings (7, 8), wherein the convex section (4) is designed complementarily to the section of the winding barrier system (11) and is mutually opposite at a distance from the winding barrier system, in order to provide the electrical device with a higher withstand voltage, it is proposed that an additional barrier (13) is arranged between the winding barrier system (11) and the convex section (4), which additional barrier has an arc-shaped section (14) which is curved radially outwardly and towards the convex section (4) and two flat, planar sections (15, 16), which planar sections each extend from the arc-shaped section (14) to a free end at an axial recess (17, 18).

Description

[0001] The present invention relates to an electrical device for connecting to a high-voltage power network, the electrical device having a container filled with an insulating fluid, the container having at least one side wall, the side wall forming a flat wall section and a radially outwardly arched convex section that expands the internal volume of the container, the convex section extending between two axial edges, the electrical device also having an active component arranged in the container, the active component having a core and at least one winding surrounding a section of the core, and the electrical device also having at least one winding barrier system surrounding one or more windings, wherein the convex section is designed to be complementary to the segment shape of the winding barrier system and is spaced apart from the winding barrier system.

[0002] Such electrical devices are known in practice. For example, a transformer has an active component comprising a magnetizable core composed of iron sheets placed against each other with their flat sides. The core forms a closed magnetic circuit. The iron sheets are pressed together by a pressing frame. For a three-phase active component, for example, the core comprises three arms connected to each other by a lower and upper yoke. Each core arm is surrounded by an inner secondary winding and an outer primary winding. The core and the windings are arranged concentrically with respect to each other.

[0003] Active components are growing larger due to increasing power and voltage, while the required transport dimensions of the container must remain constant. Consequently, the distance between the active components and the container is decreasing. However, due to the required operating voltage, this distance must not fall below a minimum.

[0004] To ensure this minimum distance, so-called raised containers are used, wherein the container has side walls that form so-called raised sections. These raised sections are located opposite the windings so that the distance between the windings and the container wall does not fall below the required minimum distance. However, a disadvantage of such raised containers is that high electric field strengths can occur due to the corners formed at the transition between the raised sections and the flat sections.

[0005] The object of the present invention is therefore to better reduce the field in the edge region and thus avoid electrical flashovers.

[0006] The present invention solves the technical problem as follows: an additional barrier is arranged between the winding barrier system and the raised section, the additional barrier having an arc section that is bent radially outward toward the raised section and two flat sections, which extend from the arc section to the free end at axial grooves.

[0007] According to the present invention, an additional barrier is arranged between the raised sections of the sidewalls to demarcate the free oil path. The additional barrier comprises an arcuate section that curves radially outward similarly to the raised section. Two flat sections are arranged on either side of the arcuate section, each extending in a plane. This creates a sharp bend, kink, or, in other words, a groove extending axially between each flat section and the arcuate section. The groove extends axially, while the arcuate section, like the raised section of the sidewall, curves radially outward and is thus arcuate. The two flat sections of the additional barrier extend from the arcuate section to its free end.

[0008] It has been shown that the additional barrier designed according to the invention divides the free oil path in an electrically advantageous manner, particularly at the bends in the side walls. Within the scope of the invention, an electrical device is thus provided whose active components can be designed for higher power, i.e., higher voltage or higher current, without having to deviate from the required transport dimensions.

[0009] The electrical device according to the present invention is, for example, a transformer or a choke valve. If the electrical device is a transformer, the transformer has one or more pairs of inductively coupled windings. The two windings of a winding pair are arranged concentrically with one another, for example, one winding being a low-voltage winding and the other being a high-voltage winding. The core arms extend through both windings as core segments.

[0010] The winding barrier advantageously consists of a series of barriers that define oil outlet channels between them, thereby effectively reducing the electric field in the radial direction. The barriers are here formed from laminated cardboard. However, such barrier systems are well known to those skilled in the art, so a detailed description of their construction is omitted here. The barrier system preferably has a cylindrical outer contour. Additional barriers extend between the barrier systems and are advantageously made of a non-conductive material, such as laminated cardboard. Alternatively, the additional barriers can also be made of paper or cardboard.

[0011] The arcuate section is advantageously designed to be complementary in shape to the convex section. According to this advantageous further development of the invention, the arcuate section has a constant distance from the convex section that is curved outward in an arcuate manner.

[0012] Further advantages arise if the flat sections extend parallel to the flat wall sections of the side walls. If the flat sections of the electrical device according to the invention are aligned parallel to the flat sections of the side walls, the electric field is further divided at the edges of the side walls.

[0013] In another advantageous variant of the invention, the additional barrier is kept at a distance from the winding barrier system and the raised section by means of at least one cover section arranged at a distance from the winding barrier system and by means of a holding band. The holding of the additional barrier is achieved within the scope of the invention by means of the holding band and by means of the cover section. Usually, the cover section that is originally installed in the container is used to hold the additional barrier. For example, a holding band designed as a flat band extends around the additional barrier system so that the holding band, for example, rests with its flat side on the outer contour of the additional barrier system. From there, the holding band is wound around the arc section of the additional barrier system, wherein suitable through-holes or gaps are provided in the additional barrier. Within the scope of the invention, the holding band is composed, for example, of cardboard, paper or other formable laminated cardboard.

[0014] An adjusting element is expediently provided, which extends between the winding barrier system and the flat section of the additional barrier. The adjusting element (which can also be synonymously referred to as a distance member) is likewise made of laminated cardboard, cardboard or paper and serves to orient the corresponding flat section of the additional barrier, the free ends of which would otherwise be freely oriented.

[0015] The adjusting elements are preferably fixed to the winding barrier system via retaining straps. For securing the corresponding flat sections, for example, the free ends of each flat section, a cord made of cardboard, paper, or another non-conductive material is used. The adjusting elements have suitable through-holes for this purpose. Each adjusting element is provided with a slot for receiving and threading the retaining strap through which the retaining strap can be guided.

[0016] The winding barrier system advantageously has a cylindrical outer contour, and the raised section defines a section of a hollow cylinder, wherein the winding barrier system and the raised section are arranged concentrically with respect to one another. As already explained above, the windings are designed cylindrically and are arranged concentrically with respect to one another and to the core arms enclosed by the windings. This embodiment of the invention also applies to the winding barrier system, which, due to its complementary shape, also acts on the raised section. The raised section is, in turn, a section or segment of a cylinder.

[0017] According to a related advantageous embodiment, the raised section and the curved section each define a section of a hollow cylinder, wherein the hollow cylinder has different radii and the raised section and the curved section are arranged concentrically with respect to one another. According to this variant, the above description of the raised section and the winding barrier system also applies to the curved section and the raised section.

[0018] Furthermore, it can be advantageous if the two edges of the side wall, between which the raised section extends, and the two recesses of the additional barrier, enclose the same angle relative to a common center point.

[0019] Further advantageous embodiments and advantages of the application result from the following description of embodiments of the application with reference to the drawings, in which the same reference symbols denote the same components, and in which

[0020] Figure 1 A cutaway top view of an electrical device according to the prior art is shown,

[0021] Figure 2 An embodiment of an electrical device according to the application is shown in a cutaway top view,

[0022] Figure 3 The fixing of the additional barrier on the winding barrier system is shown, and

[0023] Figure 4 The fixing of the cover plate section and the section of the winding barrier system is shown in a perspective view.

[0024] Figure 1 An embodiment of an electrical device 1 according to the prior art is shown from above in a cutaway cross-sectional view. The electrical device 1 shown is designed as a power transformer 1 having a tank filled with an insulating fluid, only the side wall 2 of which can be seen. The side wall 2 has a flat wall section 3 and a radially outwardly curved bulge section 4 which expands into the interior volume of the tank. The bulge section is arranged between two axially extending axial edges 5 and 6. In Figure 4 The axial edges 5 and 6 are directed axially in the drawing plane or out of the drawing plane.

[0025] The tank is shown only partially with its side wall 2, in which a high-voltage winding 7 and a low-voltage winding 8 are arranged, which are arranged concentrically relative to one another and relative to a core limb not shown in the drawing.

[0026] It can be seen that the bulge section 4 curves the interior volume of the tank outwardly in an expanded manner, so that the required minimum distance between the high-voltage winding 7 and the side wall 2 is maintained, and high electrical field strengths with voltage flashovers are avoided inside the transformer 1. However, as already set out in the above explanations, high electrical field strengths occur at the edges, which are indicated as corners in the cutaway view shown, so that the operating voltage of the power transformer cannot be increased further without voltage flashovers occurring at these corners or bends, which cause irreparable damage to the electrical device.

[0027] Figure 2 An embodiment of an electrical device 9 according to the application is shown, which is still designed as a transformer 9. The transformer 9 shown only partially in a cutaway top view has a tank or container, in Figure 2Only its side wall 2 is shown, which still comprises a flat wall section 3 and a radially outwardly curved raised section 4. The raised section 4 extends between axially extending edges 5 and 6, which extend at Figure 2 In the figure, corners 5 and 6 are shown due to the selected cross-sectional view.

[0028] The transformer 9 is filled with an insulating fluid, such as mineral oil or ester liquid. A magnetizable core is arranged inside the transformer. Figure 2 Only the core arms 10 of the core can be seen. These are concentrically surrounded by the low-voltage winding 8 and the high-voltage winding 7. The two windings 7 and 8 are in turn surrounded by a barrier system 11, which consists of individual barriers 12 spaced radially apart from one another. Oil channels are formed between the barriers 12 of barrier system 11, which increase the dielectric strength of transformer 9.

[0029] Furthermore, the additional barrier 13 can be seen, which has an arcuate section 14 facing the raised section 4, from which two flat sections 15 and 16 extend towards the free end. The arcuate section 14 is designed to be complementary to the cylindrical outer contour of the winding barrier system 11 and is designed to be complementary in shape to the raised section 4 of the side wall 2. The flat sections 15 and 16 extend essentially parallel to the flat wall section 3 of the side wall 2. In other words, the flat sections 15 and 16 extend from axial grooves 17 and 18, which extend in the direction of the winding barrier system 11. Figure 2 In the figure, it is represented as a corner due to the two-dimensional view.

[0030] exist Figure 2 In the illustrated embodiment, the curved section 14 transitions into the flat sections 15 and 16 at the axial grooves 17 and 18, respectively. In other words, the additional barrier 13 is designed as a single piece. In the illustrated embodiment, the additional barrier, like barrier 12 of winding barrier system 11, is made of laminated cardboard. However, other non-conductive materials can also be used to produce the additional barrier. For example, the additional barrier can be made of cardboard, paper, or even non-conductive plastic.

[0031] Figure 3 The attachment of the additional barrier 13 is shown in greater detail. It can be seen that the additional barrier is held at a distance from the outer barrier 12 of the winding barrier system 11 by means of a cover section 19. The cover section 19, which is also curved, is L-shaped in longitudinal section and is clamped at its shorter leg ends by a lower attachment system 20. The attachment system 20 also serves to secure the barrier 12 of the winding barrier system 11 and is arranged on the tank floor. A longitudinal gap is formed between the two adjacent cover sections 19, through which each flat section 16 of the additional barrier 13 extends.

[0032] In addition to the cover section, a holding strip 21 is provided, which is made of cardboard and is designed as a flat strip. The holding strip rests with its flat side on the outer contour of the winding barrier system 11 and is guided from there through a gap 22 in the arc-shaped section 14 of the additional barrier 13, so that the holding strip 21 surrounds the arc-shaped section from the outside and thus additionally holds the additional barrier 13.

[0033] Furthermore, the spacer or adjusting element 22 can be seen, which has a bent leg section 23, via which it rests against the outer contour of the winding barrier system 11. A holding strip is guided through the leg section, so that the leg section 23 is pressed against the winding barrier system 11 by the holding section 21. An adjusting element slot 24 is provided in the lower region of the adjusting element 22, through which the holding strip is guided.

[0034] A through-hole is provided at the end of the adjusting member 22 facing away from the foot section 23, and is aligned with the through-hole of the flat section 16 of the additional barrier 13. A fixing cord 25 made of paper is guided through the through-hole of the adjusting member 22 and the through-hole of the flat section 16, thereby securing the adjusting member 22 to the flat section 16. The fixing cord can also be made of other non-conductive materials within the scope of the present invention. The adjusting member 22 is designed to be dimensionally stable, so that it serves to securely and stably align the flat section 16 relative to the flat wall section.

[0035] Figure 4 The fixing of the cover section 19 to the fixing system 20 is shown. In particular, the L-shaped design of the cover section 19 in longitudinal section can be seen. In addition, the inner barrier 12 of the winding barrier system 11 can be seen due to the partially transparent view.

Claims

1. An electrical device (9) for connection to a high voltage power grid, having A container filled with an insulating fluid, comprising at least one side wall (2), which forms a flat wall section (3) and a radially outwardly curved convex section (4) which enlarges the inner volume of the container and extends between two axial edges (5, 6), - an active component arranged in the container, the active component having a core (10) and at least one winding (7, 8) surrounding a section of the core (10), and - at least one winding barrier system (11) surrounding one or more windings (7, 8), in, The raised section (4) is designed to complement the section shape of the winding barrier system (11) and is spaced apart from the winding barrier system, and is characterized in that an additional barrier (13) is arranged between the winding barrier system (11) and the raised section (4), and the additional barrier has an arc section (14) that is bent radially outward toward the raised section (4) and two flat sections (15, 16), and the flat sections extend from the arc section (14) to the free end at axial grooves (17, 18), respectively, wherein at least one adjusting member (22) is provided, which extends between the winding barrier system (11) and the flat sections (15, 16) of the additional barrier (13).

2. The electrical device (9) according to claim 1, characterized in that The arc section (14) is designed to be complementary in shape to the convex section (4).

3. The electrical device (9) according to claim 1 or 2, characterized in that The flat sections (15, 16) each extend parallel to a flat wall section of the side wall.

4. The electrical device (9) according to claim 1 or 2, characterized in that The additional barrier (13) is held at a distance from the winding barrier system (11) and the raised section (4) by means of at least one cover section (19) arranged at a distance from the winding barrier system (11) and by means of a holding strip (21).

5. The electrical device (9) according to claim 1 or 2, characterized in that Each adjusting element (22) is fixed to the winding barrier system (11) by means of a retaining strap (21).

6. The electrical device (9) according to claim 1 or 2, characterized in that Each adjusting member (22) is fixed to the corresponding flat section (16, 16) by means of a fixing rope (25).

7. The electrical device (9) according to claim 1 or 2, characterized in that The winding barrier system (11) has a cylindrical outer contour and the raised section (4) defines a section of a hollow cylinder, wherein the winding barrier system (11) and the raised section (4) are arranged concentrically with respect to one another.

8. The electrical device (9) according to claim 1 or 2, characterized in that The convex section (4) and the arc section (14) respectively define sections of a hollow cylinder, wherein the hollow cylinder has different radii and the convex section (4) and the arc section (14) are arranged concentrically with each other.

9. The electrical device (9) according to claim 8, characterized in that In a top view, the two edges (5, 6) of the side wall (2) and the two recesses (17, 18) of the additional barrier (13) enclose the same angle relative to a common center point.

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