DE3446061A1 - Current busbar for a medium-voltage or high-voltage switching and distribution installation, and intermediate supports for this busbar - Google Patents

Abstract

For a current busbar (10) (from here on referred to only as a "busbar"), which can be allocated to a medium-voltage or high-voltage switching and distribution installation and has an essentially circular or elliptical external cross-sectional contour, and to which at least one insulating intermediate support (19) can be linked for its retention and in order to fix its position, it is proposed to provide it with at least two approximately U-shaped, groove-like constrictions (11, 12), which are distributed approximately uniformly on its circumference and whose side walls (13, 14; 15, 16) merge in a sharply curved manner into the circular or elliptical external cross-sectional contour. The intermediate support (19) is intended to be constructed, as the busbar (10), with a surrounding ring at a considerable distance from whose internal edge spoke-like supporting arms (20, 21) originate which point into the interior of the ring, whose number corresponds to the number of groove-like constrictions on the busbar, and whose free ends engage in the groove-like constrictions and here extend as far as the busbar, supporting it. In this way, the occurrence of partial discharges on the gaps of touching surfaces can be largely or completely prevented. <IMAGE>

Description

BROWN, BOVERI & CIE AKTIENGESELLSCHAFT

Mannheim - Dec. 14, 1984

Mp. No. 686/84 ZPT / P4-Pa / Sd

Busbar for a Kittelvoltage or high-voltage switching and distribution system and intermediate support for this busbar

The invention relates to a medium voltage od High-voltage switchgear and distribution system assignable busbar (hereinafter only referred to as "busbar"), which is substantially circular or elliptical Has outer cross-sectional contour and on which at least one insulating intermediate support for their support and fixing in position is attachable.

There are disc-shaped or funnel-shaped supports or intermediate supports are known which, for example, have widenings on their outer and inner edges, i.e. at their contact surfaces with the busbar to be supported and on the contact surfaces of their holder, for example within an encapsulation. The problem here is the occurrence of partial discharges in the gaps - the mentioned contact surfaces. To prevent this risk:

are the known supporters or intermediate supports with control electrodes equipped or with cast in the support

• Part number: 686/84 - 2 - ■ 3 A 46061

ν 'metal fittings, a so-called potential control to serve. This inevitably adversely affects the costs for the supporters; In addition, however, quality problems must also be taken into account and, in particular, a certain one arises Examination effort for checking for a gap-free fitting pouring.

The invention has for its object to provide intermediate support for To create busbars which are particularly inexpensive to manufacture, easy to assemble and which Cast-in fittings can be avoided without having to accept the disadvantages described, i.e. in other "words: these intermediate supports must be free of partial discharge up to to a desired degree of tension.

This object is achieved according to the invention by the following measures, namely to create a special busbar, which has at least two approximately U-shaped groove-like constrictions that are approximately evenly distributed on its circumference.

has, the side walls of which are strongly rounded into the otherwise essentially circular or elliptical ♦ Pass over the outer cross-sectional contour, and the rest of the intermediate support to be created as one with the busbar to form a clear distance surrounding ring, from its inner edge - corresponding to the number of groove-like constrictions on the busbar - go out into the ring interior directed spoke-like support arms, the free ends of which in the Engage groove-like constrictions on the busbar and extend here to the busbar - supporting it.

This ensures that the support or its support arms Connect to the busbars in an almost field-free space, so that a partial discharge in the inevitable gaps at the contact surface between the busbar and Intermediate support or its support arms cannot be expected in the first place. But for this it is - as already stated above - necessary, the two side surfaces or wall

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Mp. No. 686/84; _ ^ _.

fertilize said groove with a sufficiently large radius open into the outer contour of the busbar. *

An improvement of this effect just described can be achieved through a further development of the inventive concept, according to which the width of the base of the groove-like constrictions is at least a few millimeters larger than al £ the width of the engaging Tragarraendes of the intermediate support between the reaching to the busbar ends of the support arms and the side walls of the said groove-like constrictions are each two or more millimeters Distance.

Another advantageous embodiment of the inventor Dung can be seen in the proposal, the flat basic surfaces of the groove-like constrictions with at least one raised protrusions in the cross-sectional shape: and / or to be equipped with a groove-like recess and formations in the same direction at the free ends of the support arms provide that engage positively in these first-mentioned formations. This is a well-defined Guaranteed position of the intermediate support in the said groove-like constriction.

Further useful refinements relate to the intermediate support. For this purpose, it is suggested, for example, to make the support arms relatively wide in their area starting from the inner edge of the ring, i.e. double or three times as wide as its free end, the

3Q support arm contour approximately conical towards its free end or hyperbolically tapered. Here it is necessary to make the transition from the ring part to the support arm with sufficient to provide large radii. Such a training can still be improved in its desired mode of action, if a triangular outbreak is found on the (i.e. wide) area of the support arm facing the inner edge of the ring with strongly rounded corner areas. Such

x. In this context it should be mentioned that the previously mentioned "Strong edges" are meant with comparatively large radii, but not only geometrically exact circular arc shapes are meant.

Mp. No. 686/84 - L * -

Measure meets the knowledge that cavities or airways or gas routes, if they are in favorable places be introduced, able to reduce the electric field strength. Also, through an outbreak like him was mentioned, a material saving was achieved.

To further improve the freedom from partial discharge of the intermediate support, it is further proposed at least to widen the outer ring area significantly compared to the somewhat further inner ring area and above all compared to the thickness of the support arms.

An appropriate design proposal is also included therein see to externally surround the ring area with a hoop-like circumferential projection which can be inserted in a groove for a holder for the intermediate support. Such The holder can be an encapsulation, for example. In this Case, the proposal is made, the bracket and precise definition of the position for the intermediate support at the joint 'two Provide encapsulation elements, the tire-like projection around the ring area of the intermediate support in corresponding recesses engage at the ends of the encapsulation elements.

Based on the drawing and the explanations of the individual figures in this drawing, the invention and its advantageous design options are explained again.

It shows:

Fig. 1 is a section through a massive busbar with a intermediate supports attached to it,

2 shows a section through an essentially tubular busbar with an intermediate support applied to it,

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Mp.-No. _V 686/84

3 shows a specially designed support arm of an intermediate support /

Modifications of the training according to FIG. 3 and

4 shows a small longitudinal section of an encapsulation with a busbar arranged therein and a Intermediate supporters.

Figure 1 shows a massive busbar, '10, with some essentially circular cross-sectional contour. It can be seen that the circular shape of this cross-sectional contour is two-sided opposite, approximately U-shaped groove-like constrictions' and 12, the side walls 13 and 14 (in de Constriction 11) or 15 and 16 (with constriction 12) mj strong curves in the otherwise circular cross-sectional contour the busbar 10 pass. Not unexpected at this point it remains that on the actually flat base surface these groove-like constrictions 11 and 12 each have a recess 17 and 18 formed therein. In these wells 1? and 18 do not apply more detailed numbered formations of an au the busbar 10 applied intermediate support 19 a ο more precisely: formations on support arms 20 and 21, which Intermediate support 19 go out. This intermediate support 19 is a kind of ring, which with a clear distance d Busbar 10 surrounds and from which, as just mentioned, the support arms 20 and 21 go out. Remarkable here is that the transitions from the ring part of the intermediate stud Zers 19 in the inwardly directed support arms 20 and 21 st are rounded, and further that the width of the support arms; and 21 at their free ends, which are thus in the groove-like in lacing 11 and 12 engage, is significantly less than the width of the groove bottom of these constrictions. There are as < each a few millimeters distance 'between the side Ra] fertilize these support arms 20 and 21 and the adjacent side Walls 13 and 14 or 15 and 16 of the constrictions 11 and available. In addition, what cannot be inferred from this illustration is the outer area of the ring part

Mp. No. '' 686/84 - · · - # - ο / / r n c-ι

. · 'Of the intermediate support 19 widened on both sides, i.e. in the longitudinal direction of the busbar 10.

Figure 2 illustrates, also in cross section, a tubular busbar 25, the essential contour of which is made up of approximately semi-tubular areas 26 and 27 and one Connecting web 28 composed. Compared to a massive busbar, as it has been indicated in Fig. 1, a busbar, as shown here, has significantly better heat dissipation results and therefore a higher current carrying capacity per unit cross-sectional area. The formations on the side edges of the semi-tubular areas or 27 are irrelevant here, but of interest are the groove-like constrictions 29 and 30, which are also present here, their training, as far as the outer contour of the busbar is concerned, the constrictions 11 and 12 in FIG. 1 practically completely the same, so that further explanations are unnecessary. Also in these groove-like constrictions 29 and 30 free ends of support arms 31 and 32 of an intermediate support 53 engage. This intermediate support 33, which incidentally is in the illustration is shown broken off on both sides for reasons of space, corresponds completely to that (19) in Fig. 1, with the exception of the fact that its support arms 31 and 32 in the area of the ring part are wider than theirs free ends, i.e. they taper conically or wedge-shaped in their course towards the free end. But here too clearly the large roundings at their exit area from the ring part of the intermediate support 32 and here too are at the free ends (not numbered) projections arranged, which in corresponding recesses in the groove base of the groove-like Constrictions 29 and 30 engage.

Fig. 3 shows a smaller part of an intermediate support 35 with a support arm 36 extending therefrom. This support arm has, at least in this view, a hyperbolic one Tapering towards its free end and is in

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Mp. No. «« D / 04 - - * f -

The rest is provided with a triangular cutout 37, but the corner areas ¹¹ are very strongly rounded. This carbon black break 37 not only serves to save material, but also reduces the dielectric properties of the intermediate support 35 - as already indicated at the beginning - definitely improve to OO. As can be seen in this illustration, the free end of this support arm 36 also extends into a groove-like constriction 38 of an only partially indicated busbar 39 and abuts this busbar 39. Here, too the groove-like constriction 38 is formed with a significantly larger clear width than is the case at the free end of the support arm 36. In contrast to the previously shown embodiments, the constriction 38 is here on the groove bottom instead of a depression (e.g. 17 in FIG. 1) now a projection 40 is formed and accordingly a (not numbered) recess at the free end of the support arm 36. The effect of these formations is to be assessed as the same in both cases and practically also as equivalent.

Modifications of the outbreak 37 according to FIG. 3 show the figure 3a with a strongly drawn up triangular outbreak 41 and Figure 3b with

a circular eruption 42. /

Finally to Figure 4. There is a small area here an encapsulation with encapsulation elements 45 and 46 their joint shown in section. Within this encapsulation, a busbar 47 can be seen, which is attached to this Place is carried or supported by an intermediate supporter 48. Of this intermediate support 48 is, however only the lower area (in the illustration) is shown, i.e. it has been broken off towards the top to create recesses 49 and 50 to make it easier to see which are located at the joints between the encapsulation elements 45 and 46. In these recesses 49 and 50 are joined by a projection 51, which projects over the ring part of the intermediate support 48 and - through its insertion into the recesses 49 and 50 - the precise position fixing of the intermediate support 48 is used. Has been mentioned and in this illustration the widening on the outer area of the ring part of the intermediate support can now also be seen 48, which extends to both sides and is formed by corresponding formations 52 and 53.

. - "As already said at the beginning of the description of the figures, the illustrations are merely illustrative embodiments of the invention Manifold variations thereof are conceivable, in particular is es.möglich and in certain cases.

5 even expedient, instead of just providing two support arms, three or more support arms and these at regular intervals to arrange the busbar. This would be the case in particular with busbars that are very heavy in terms of weight or those, .the extreme electrodynamic

10 forces could be exposed.

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Reference numerals

Busbar

groove-like constrictions on the side walls and 11

Indentations

Intermediate support arms on

- free -

and 12

at 11 at 12

Fig. 1

25 26 ^> 27J 28

29} 30)

Busbar

semi-tubular areas v .. 25

Connecting web

groove-like constrictions on 25

Support arms v.

Intermediate supporters

- free -

Fig. 2

copy I.

Reference numerals

35 Zv / ischenstützer 36 Beam 37 triangular outbreak 38 groove-like constriction 39 Busbar 40 head Start 41 42 43 44 45)
46J Encapsulation is e j
47 Busbar 48 Intermediate supporters 49]
5OJ 45
Recesses on
46 51 Head Start i
53) Notches at 48 54

Fig. 3

Fi £ 4 COPY

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Claims (8)

Expectations 1. A current busbar (hereinafter referred to as "busbar") that can be assigned to a medium-voltage or cooking voltage switchgear and distribution system, which essentially has a circular or elliptical outer cross-sectional contour and to which at least one insulating intermediate support can be attached to hold it and fix it in position, characterized in that the busbar (10, 25, 39, 47) at least two approximately U-shaped groove-like constrictions that are approximately evenly distributed over its circumference (11, 12; 29, 30: 38), the side walls (13, 14; 15, 16) of which are strongly rounded into the circular or elliptical outer cross-sectional contour pass over, and that the intermediate support (19,33,35,48) as the busbar at a clear distance surrounding ring is formed, of the inner edge corresponding to the number of groove-like Constrictions on the busbar in the interior of the ring directed spoke-like support arms (20, 21: 31 »32; 56) from- · Go, the free ends of which engage in these groove-like constrictions and here up to the busbar - supporting them - are sufficient. 2. busbar and intermediate support according to claim 1, Width of the characterized in that the base surfaces of the nutaruigen Constrictions (11, 12; 29, 30; 38) is at least a few millimeters larger than the width of the engaging free support arm ends (ends of 20, 21; 31, 32; 36) of the intermediate supports (19, 33, 35, 48).
35 COPY . Mp.-No ... 686/84 ... --W- - o // rnri β 344bUb ι 3. busbar and intermediate support according to claims 1 or 2, characterized in that the to flat base surfaces of the groove-like constrictions (11, 12; 29, 30; 38) at least one in the cross-sectional shape representative raised projection (40, Fig. 3) . themselves
and / or have a corresponding groove-like recess (17, 18, Fig. 1) and that these formations in the same direction formations on the free ends of the support arms (20, 21; 31, 32; 36) of the intermediate support (19, 33, 35) intervene positively. 4. intermediate support according to one of claims 1 to 3, characterized in that the support arms (31, 32; 36) in Their area starting from the inner edge of the ring has a width that is about twice or several times greater than at its free end, the support arm contour approaching its free end conical or conical. wedge-shaped or hyperbolically tapered (Fig. 2 and 3). 5. intermediate support according to claim 4, characterized in that the support arms (36) in their inner edge of the ring facing area have a triangular breakout (37,41) with strongly rounded corner areas or instead an at least approximately circular recess (42) or a combination of two or more such outbursts. 6. Zv / i schens does ζ he according to one of claims 1 to 5, characterized in that at least its outer ring area is significantly widened compared to the thickness of the from the ring area outgoing support arms (Fig. 4). Mp.-No. '''686/84.' -Jn-- of / ΩΠΩΛ 7. intermediate support according to one of claims 1 to 6, characterized in that its ring area is surrounded by a tire-like, circumferential projection (51), which can be inserted into a groove (49 + 50) of a holder for the intermediate support (48). 8. intermediate support according to claim 7, characterized in that the holder for the intermediate support (48) is formed at the joint between two encapsulation elements (45, 46) and is fixed by means of these encapsulation elements in that the tire-like projection (51) around the ring area in corresponding recesses (49, 50) engage in the mutually facing ends of the encapsulation elements.