Patent Application
20100300852
This application claims priority as a continuation application under 35 U.S.C. ยง120 to PCT/EP2008/010260, which was filed as an International Application on Dec. 4, 2008 designating the U.S., and which claims priority to European Application 07023713.6 filed in Europe on Dec. 7, 2007. The entire contents of these applications are hereby incorporated by reference in their entireties.
The disclosure relates to a low-voltage, medium-voltage or high-voltage switchgear assembly, such as assemblies with at least one moveable contact piece, in which the moveable contact is connected to a stationary connection piece electrically with a flexible connection means.
Switching devices are known, in for example, the medium-voltage range. These switching devices can be equipped with so-called pole parts, in which vacuum interrupter chambers can be installed or cast in as actual switching elements.
The pole parts can have two stationary connection pieces, to which the switching device in the switchgear assembly can be connected to further components. The stationary connection pieces can be connected to the feed lines of the vacuum interrupter chamber within the pole part. This connection can be designed to be rigid on one side, for example, the fixed contact side. On the other side, for example, the switching contact side, the stationary connection piece of the pole part can be connected to the moveable feed line of the vacuum interrupter chamber in such a way that a relative movement of the moveable feed line is made possible. This can be achieved, for example, by a rolling contact, a multi-contact system or a connector strip. Connector strips are usually in the form of separate component parts, which also need to be fitted separately.
DE 9017054 U1 discloses a switch pole arrangement with a moveable connector strip. This document describes an arrangement of an open pole part, in which a vacuum interrupter chamber can be installed in the tubular pole part via corresponding mounts. The moveable feed line can be connected to the connection piece of the pole part, in this case in the form of a busbar, by a connector strip. The fixing of the connector strip in this case takes place by screws.
Ring-type connector strips are also known.
The sum of all the electrical resistances in the pole part can result, during operation with current flow, in heating of the pole part which should not exceed a specific temperature level (predetermined by standards and material properties). For this reason, reducing the total resistance of the pole part (greater conductor cross sections, material selection, optimization of the transfer resistances) can be desirable.
Connecting the connector strip to the connection piece of the pole part by screw connections can result in the connecting point having a relatively high electrical transfer resistance. This is brought about by the only partial surface contact of the connector strip and the connection piece in the region of the screw connection. Furthermore, the screwed connecting point can have a relatively high thermal resistance. Since the thermal energy which arises in the pole part is principally dissipated via the connection pieces and the conductors connected thereto, the screw connection not only can result in an increase in the thermal energy produced but also in a reduction in the thermal conduction and therefore overall in greater heating of the pole part.
A voltage switchgear assembly is disclosed comprising at least one moveable contact piece, and a connection piece electrically connected to the moveable contact piece with a flexible connecting means, wherein the flexible connecting means is cohesively connected to the connection piece.
A voltage switchgear assembly is disclosed comprising at least one moveable contact piece, and a connection piece electrically connected to the moveable contact piece with a flexible connecting means, wherein the flexible connecting means is cohesively connected to an intermediate piece which is cohesively connected to the connection piece.
The disclosure is illustrated in the drawings and described in more detail below.
The connection between a connector strip and a connection piece of a pole part which has an electrical and thermal resistance is disclosed which can be low while maintaining the mechanical properties of a known connector strip.
In the connector strip, a flexible connecting means is connected to a connection piece directly or with an intermediate piece, which can be connected to the connection piece, cohesively or at least unreleasably.
In the case of known designs, the connector strip between the contact piece feed line and the connection piece, can be a separate component part, which is fitted to the contact piece feed line of the contact piece, but also additionally is fitted to the connection piece. Releasable connections produce transfer resistances, however. As a result of the high potential current levels, a high power can be released via the transfer resistances, and this can result in a heat flow from the conductors.
In this case moreover the term connection piece is intended to reference a connection piece which runs through the pole part wall for an external contact to the outside.
In order to reduce thermal heating within the pole part, the transfer resistance between a connecting means, such as a connector strip and a connection piece can be reduced in a manner as disclosed herein. In this case, the connecting point may be a cohesive (e.g., a materially cohesive), transition between the connection piece and the connector strip.
A further exemplary configuration provides a connecting means integrally formed materially cohesively on the connection piece or on the intermediate piece in such a way that it forms, with the connection piece or the intermediate piece, an integral unit. This form can provide the least transfer resistance.
A further exemplary configuration provides that the connecting point between the connection piece and the connecting means, for example, the connector strip, can be a pressed or cast connection.
A further exemplary configuration provides that the connection piece can be a hollow-cylindrical metallic component part, in which the hollow cylinder can be parallel to the contact piece actuation axis and at least one connecting means can be arranged within the hollow cylinder and is connected to the hollow cylinder section integrally and materially cohesively or in pressed fashion.
A further exemplary configuration can include two connector strips that can be arranged on diametrically opposite sides and can be attached centrally one above the other to the contact piece feed line of the moveable contact piece.
In alternate embodiments, the connector strips can be designed to be flexible.
A further exemplary configuration can include connector strips that can be fitted in such a way that they are bent forwards in one direction. In this case, greater flexibility in the mechanical actuation excursion is made possible.
A special but likewise effective exemplary configuration includes four connector strips, in each case two diametrically positioned connector strips, arranged in such a way that they are bent forwards in one direction.
An exemplary embodiment includes a type of sheet membrane can be provided as the connecting means. The sheet membrane can be connected centrally with screws on the moveable contact pin and at the edge to the hollow-cylindrical section of the connection piece.
As a result of the configuration in which the sheet membrane is a concentrically corrugated membrane, increased flexibility when implementing the membrane can be achieved.
In the previous embodiment, it has been assumed that the pressed or fused-in connector strips are known connector strips. The connection to the vacuum interrupter chamber then takes place via the existing drilled-through holes in the end faces of the connector strips by a pushed-through connection.
As in the case of the connector strips, it can be desirable to place a large number of corrugated washers one above the other for sufficient current-carrying capacity. In an essentially air-tight embodiment shown, during switching, the compression or decompression of the air enclosed between the membrane and the vacuum interrupter chamber can result in damping of the switching process. This can lead to an optimized switching response of the circuit breaker as a result of the reduced rebound response or reverse response during opening of the contact pieces. In order to vary the damping, it is possible to provide the corrugated washers with defined openings (for example drilled holes) in order to produce targeted pressure compensation. In addition, the openings can contribute to the cooling of the current transfer as a result of the air exchange produced.
Thus, it will be appreciated by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restricted. The scope of the invention is indicated by the appended claims rather than the foregoing description and all changes that come within the meaning and range and equivalence thereof are intended to be embraced therein.
| Number | Date | Country | Kind |
|---|---|---|---|
| 07023713.6 | Dec 2007 | EP | regional |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2008/010260 | Dec 2008 | US |
| Child | 12795093 | US |
