Device for Conducting Electrical Direct Current

Abstract

A device for conducting electrical direct current, wherein the device includes at least one bus bar and at least one electrically conducting edge element that is connected to the bus bar in an electrically conducting manner and has a lower electrical conductivity than the bus bar, where the edge element is arranged on a lateral outer face of the bus bar and extends along the bus bar.

Claims

1.-9. (canceled)

10. A device for conducting electrical direct current, comprising: at least one bus bar; and at least one electrically conducting edge element having an electrically conducting bond to the bus bar and having a lower electrical conductivity than the bus bar, said at least one electrically conducting edge element being arranged on a lateral external surface of the bus bar and extending along the at least one bus bar; wherein at least two edge elements are arranged on the at least one bus bar on lateral external surfaces of said at least one bus bar which lie opposite each other.

11. The device as claimed in claim 10 wherein a plurality of bus bars are arranged alongside each other in a stack-like manner.

12. The device as claimed in claim 11 wherein at least one edge element which extends across the plurality of bus bars arranged alongside each other in the stack-like manner; wherein said least one edge element is arranged on lateral external surfaces of the plurality of bus bars and is bonded to each of the plurality of bus bars in an electrically conducting manner.

13. The device as claimed in claim 10, wherein the at least one bus bar is made of one of copper and aluminum.

14. The device as claimed in claim 10, wherein the at least one edge element is made of one of iron or a steel.

15. The device as claimed in claim 14, wherein the at least one edge element is made of stainless steel.

16. The device as claimed in claim 10, wherein the at least one bus bar has one of a strip and plate-shaped construction.

17. The device of claim 10, wherein the device limits electrical short-circuit currents in an electrical circuit arrangement; and wherein the at least one bus bar of the device is electrically bonded to one pole of an electrical direct current source.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The properties, characteristics and advantages of this invention described above, together with the way and manner in which these are achieved, will become more clearly and plainly comprehensible in conjunction with the following description of exemplary embodiments, which are explained in more detail in conjunction with the drawings, in which:

[0018] FIG. 1 is an exemplary graphical plot of a short circuit current in a direct current circuit arrangement; and

[0019] FIG. 2 is a cross-sectional view of a device in accordance with the invention for conducting electrical direct current.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0020] FIG. 1 shows an exemplary graphical plot I(t) of a short-circuit current I in a direct current circuit arrangement, as a function of time t. The current strength of the short-circuit current I changes with a high frequency about a mean value that decreases over time. Here, the high-frequency changes in the short-circuit current I can be caused and influenced by various electrical components in a direct current circuit arrangement, such as by rectifiers or capacitors.

[0021] FIG. 2 shows a cross-sectional view of a device 1 in accordance with the invention for conducting an electrical direct current. The device 1 incorporates two bus bars 3 and two edge elements 5.

[0022] The two bus bars 3 are of the same type, and are each made in a strip-shaped form with a rectangular cross-sectional area, and is made, for example, out of copper or aluminum. The two bus bars 3 are arranged alongside and parallel to each other in a stacked manner, with a space between them.

[0023] The two edge elements 5 are of the same type and are each made in a plate-like form with a rectangular cross-sectional area and are made, for example, of iron or steel, particularly stainless steel.

[0024] Each edge element 5 lies against both bus bars 3, with the edge elements being arranged against opposite sides of the bus bars 3. In this way, a surface of each edge element 5 lies against a lateral external surface 7 of each bus bar 3, and has an electrically conducting bond to both bus bars 3 via these lateral external surfaces 7. Each of the two edge elements 5 extends, orthogonally to the plane of the drawing in FIG. 2, over the entire length of the bus bars 3.

[0025] The edge elements 5 are, for example, spaced apart by the bus bars 3 by about ten times the spacing between the bus bars 3. The thicknesses of the bus bars 3 and the edge elements 5 each correspond, for example, to about the spacing of the bus bars 3 from each other. For example, the thicknesses of the bus bars 3 and the edge elements 5, and the spacing of two bus bars 3 from each other, is in each case about 10 mm, and the spacing of the edge elements 5 from each other amounts to about 100 mm. Here, the thickness of a bus bar 3 or of an edge element 5, as applicable, is in each case to be understood as the length of one of the shorter sides of the rectangular contour of the cross-sectional area respectively of the bus bar 3 or the edge element 5.

[0026] In direct current circuit arrangements use is made, for example, of two of the devices 1 shown in FIG. 2, where the bus bars 3 of one of these devices 1 are electrically connected to one pole of an electrical direct current source and the bus bars 3 of the other device 1 are electrically connected to the other pole of the electrical direct current source.

[0027] Electrical currents that are changing at a high frequency are diverted by the skin effect and the proximity effect out of the bus bars 3 and into the edge elements 5, and are suppressed by the high electrical resistance of the edge elements 5. Simulations have shown that with this advantageous arrangement the electrical resistance of a device 1 as shown in FIG. 2 is increased, for electrical currents which are changing at a high frequency, several times over as compared to the electrical resistance of the bus bars 3, for example, by a factor of 39 for current change frequencies of 1000 Hz, when use is made of copper bus bars 3 with a cross-sectional area of 2000 mm.sup.2 and edge elements 5 made of iron. In the case of a short-circuit current I with a pulse height of 220 kA, this leads to a voltage drop of some 75 V/m across a device 1. If stainless steel is used instead of iron for the material of the edge elements 5, the electrical resistance of a device 1 for currents changing with a high frequency, and the voltage drop across the device 1, can be further increased.

[0028] Although the invention has been illustrated and described in more detail by preferred exemplary embodiments, the invention is not restricted by the examples disclosed, and the person skilled in the art can deduce other variations from it without going outside the scope of the protection for the invention.

[0029] 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 element 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.