DE102022003916A1 - DC and AC busbar with wavy geometry in the direction of current flow - Google Patents

Abstract

The advantage of the wavy busbar when using alternating current (AC) is that it counteracts the skin effect. The wavy geometry significantly increases the surface area. Depending on the thickness of the busbar and the technically possible bending parameters, even 50% or more can be achieved. The special wavy geometry is installed in the lengthwise direction of the busbar and thus in the direction of current flow in the busbar. The direction of current flow is always from one screwing point or screwing points or one side to other screwing points on the other side. The busbar can be made from the common materials for electrical applications, i.e. copper, aluminum, ceramic and other electrically conductive materials. The wavy geometry is used as a cooling geometry for the DC busbar. Due to the larger surface area with the same cross-section compared to a conventional busbar with rectangular geometry, more heat can be dissipated through thermal radiation. By avoiding heating of the busbars, the power loss can be kept low. The busbar is relatively robust due to its geometry and is significantly strengthened by the additional wavy geometry, which can absorb high vibrations.

Description

This invention is a current conductor, also called a busbar, with a special wavy geometry (6) and two or more contact surfaces for electrical conductors (1).

The busbar has a screwing point 1 ( ) and a screwing point 2 ( ,(3)) or several screwing points for busbars ( /7). The size and design, i.e. diameter of the screwing points and dimensions of the busbars can be designed as desired. From the screwing point 1 ( ) to screwing point 2 ( ) a current flows or vice versa depending on the direction of flow of the current (5). The screwing points 1 and 2 can also be designed with threads or with press-in nuts.

Multiple screwing points, i.e. 1 to 2,3,4 or 1,2 to 3,4,5 and so on are also part of this invention and can be manufactured.

The special wavy geometry is arranged in the longitudinal direction of the busbar (6) and thus in the current flow direction of the busbar. This also applies to angled or special forms of busbars ( until ) . The direction of current flow is always from one screwing point or screwing points or one side to the other screwing point or screwing points on the other side ( 1 , 3 , 5 ).

The advantage of this geometry is that it can be produced preferably in the punching and forming process with little additional cost for the tool.

The busbar can be made from common materials, i.e. copper, aluminum, ceramic and other electrically conductive materials. The wavy geometry significantly increases the surface area while maintaining the same cross-section.

1. 1) Als Anwendung als Wechselstromschiene AC kommt meistens der Skin-Effekt zum tragen. Der Skin-Effekt ist die Eigenschaft von Wechselströmen, bei der nur die Oberfläche eines Leiters für den Transport der Ladungsträger zur Verfügung steht. Beim Gleichstrom wird der komplette Leiterquerschnitt von Ladungsträgern durchflossen. Beim Wechselstrom werden in Abhängigkeit der Frequenz Wirbelströme und elektrische Felder erzeugt, die die Ladungsträger in die Haut (englisch: Skin) des Leisters verdrängen. Dabei dienen die elektrischen Felder als Träger der Energie dienen. Dabei verringert sich aber auch der für die Ladungsträger nutzbare Leiterquerschnitt, wobei der Wirkwiderstand des Leiters zunimmt. Durch die wellige Geometrie wird die Oberfläche deutlich vergrößert. Je nach dicke und technisch mögliche Biegeparameter können sogar 50% und mehr erreicht werden. Dem Skin Effekt kann also durch diese Wellige Geometrie entgegengesteuert werden.
2. 2) Bei der Gleichstromschiene DC wird die wellige Geometrie (6) als Kühlgeometrie genutzt. Durch die größere Oberfläche bei gleichbleibendem Querschnitt zu einer klassischen Stromschiene kann mehr Wärme durch die Wärmestrahlung abgeleitet werden. In vielen Anwendungen z.B. Hochvoltbereiche ist in der Praxis eine Erwärmung der elektronischen Bauteile und Stomschienen ein großes Problem. Hier kann durch die geriffelte Geometrie entgegengesteuert werden, und zusätzliche Kühlpads und Kühlkanäle in der Konstruktionen können vermieden werden. Dies spart erhebliche Kosten in der Produktion und Fertigung. Durch die Vermeidung der Erwärmung der Stromschienen kann die Verlustleitung gering gehalten werden.
3. 3) Die Anwendungsgebiete dieser Stromschienen können vielfältig sein. Sie kann in allen Bereichen für Hochvoltanwendung eingesetzt werden. z.B. Automobilindustrie, Gebäudetechnik, Luft- und Raumfahrt, Bahnindustrie und vielen anderen Bereichen. Die Stromschiene ist durch Ihre Geometrie relativ robust und wird durch die zusätzliche Riffelung noch deutlich verstärkt, was hohe Schwingungen abfedern kann. Gegenüber Hochvoltkabel ist dies ein erheblicher Vorteil, da die Kabel durch ihre Eigenfrequenz sehr Schwingungsfreudig sind.
4. 4) Ausserdem kann die wellige Stromschiene in vielen unterschiedlichen Stanzformen problemlos also Sonderform hergestellt werden.

This special busbar offers several advantages:

1. 1) When used as an AC busbar, the skin effect is usually used. The skin effect is the property of alternating currents in which only the surface of a conductor is available for the transport of charge carriers. With direct current, charge carriers flow through the entire conductor cross-section. With alternating current, eddy currents and electric fields are generated depending on the frequency, which displace the charge carriers into the skin of the conductor. The electric fields serve as carriers of the energy. However, the conductor cross-section that can be used for the charge carriers is also reduced, and the effective resistance of the conductor increases. The wavy geometry significantly increases the surface area. Depending on the thickness and technically possible bending parameters, even 50% or more can be achieved. The skin effect can therefore be counteracted by this wavy geometry.
2. 2) The DC busbar uses the wavy geometry (6) as a cooling geometry. Due to the larger surface area with the same cross-section compared to a classic busbar, more heat can be dissipated through thermal radiation. In many applications, e.g. high-voltage areas, heating of the electronic components and busbars is a major problem in practice. This can be counteracted by the corrugated geometry, and additional cooling pads and cooling channels in the construction can be avoided. This saves considerable costs in production and manufacturing. By avoiding heating of the busbars, the power loss can be kept low.
3. 3) The application areas of these busbars are diverse. They can be used in all areas for high-voltage applications, e.g. automotive industry, building technology, aerospace, rail industry and many other areas. The busbar is relatively robust due to its geometry and is significantly reinforced by the additional corrugation, which can absorb high vibrations. This is a significant advantage over high-voltage cables, as the cables are very prone to vibration due to their natural frequency.
4. 4) In addition, the corrugated busbar can easily be manufactured in many different punching shapes, including special shapes.

List of reference symbols

1

Contact surfaces on electrically conductive surfaces

2

Screwing point 1 or more

3

Screwing point 2

4

Screwing point 3 or more

5

Current flow direction

6

Wave-shaped contour in the direction of current flow (larger surface than classic busbar, “state of the art is the rectangular shape”)

Claims (6)

What is to be protected is the particularly wavy geometry in the direction of current flow between two or more screwing points, be it by machining, production as an extruded profile or embossed structure using a punching and bending tool or another tool. The patent claim from 1) applies to a single current rail with screwing point 1 of the current flow direction to screwing point 2 The patent claim from 1) applies to a busbar with several screwing points from one or more sides of the current flow direction to the other side or even several sides. The patent claim from 1) should also apply to special forms of busbars The patent claim applies to all common electrically conductive materials The patent claim also applies to similar wave-shaped geometries, e.g. rectangular or triangular wave-shaped arrangement in the direction of current flow

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