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EP-4735901-A1 - SHUNT COMPRISING REGIONS WITH DIFFERENT DENSITIES

EP4735901A1EP 4735901 A1EP4735901 A1EP 4735901A1EP-4735901-A1

Abstract

The invention relates to a shunt for measuring an electric current. The shunt has an input region (1) with at least one input contact (4), and the shunt has an output region (3) with at least one output contact (5), wherein the shunt has at least one measuring section (2) which is arranged between the input region (1) and the output region (3). The invention is characterized in that the input region (1), the measuring section (2), and the output region (3) have the same material, and the measuring section (2) has a lower density than the input region (1) and the output region (3).

Inventors

  • KARANOVIC, Stefan
  • KLUG, ANDREAS
  • NEUWIRTH, WERNER
  • REISINGER, ERWIN

Assignees

  • AVL List GmbH

Dates

Publication Date
20260506
Application Date
20240628

Claims (10)

  1. 1. Shunt for measuring electrical current, wherein the shunt has an input area (1) with at least one input contact (4) and the shunt has an output region (3) with at least one output contact (5), and wherein the shunt has at least one measuring section (2) which is arranged between the input region (1) and the output region (3), characterized in that the input region (1), the measuring section (2) and the output region (3) comprise the same material and the measuring section (2) has a different density than the input region (1) and the output region (3).
  2. 2. Shunt according to claim 1, characterized in that the measuring section (2) has a lower density than the input region (1) and the output region (3).
  3. 3. Shunt according to claim 1 or 2, characterized in that the measuring section (2) has a porosity which is higher than the porosity of the input region (1) and the output region (3).
  4. 4. Shunt according to claim 1 or 2, characterized in that the measuring section (2) has a porosity which is lower than the porosity of the input region (1) and the output region (3).
  5. 5. Shunt according to one of claims 1 to 4, characterized in that at least the measuring section (2), preferably also the input region (1) and the output region (3), are manufactured additively.
  6. 6. Shunt according to one of claims 1 to 5, characterized in that a cross-sectional area of the measuring section (2) and cross-sectional areas of the input region (1) and the output region (3) in the region of the connection to the measuring section (2) have substantially the same sizes.
  7. 7. Shunt according to one of claims 1 to 6, characterized in that both the input region (1) and the output region (3) each have at least one measuring contact (6).
  8. 8. Shunt according to one of claims 1 to 7, characterized in that the density of the measuring section (2) along the measuring section (2) is substantially uniform.
  9. 9. Current measuring device with a shunt for the current to be determined to flow through, wherein the shunt is designed according to one of the preceding claims, and wherein the current measuring device has a voltmeter (14) for measuring the voltage drop along the measuring section (6), which is electrically connected to measuring contacts (6) of the shunt and the current measuring device has an evaluation unit (13) for calculating the current flowing through the shunt (1), and that the evaluation unit (13) is connected to the first voltmeter (14).
  10. 10. A method for measuring an electric current with a shunt, comprising the following steps: Providing at least one shunt according to one of claims 1 to 8 or a current measuring device according to claim 9; Conducting the current to be determined through the measuring section of the shunt, which has a different density than the input area (1) and the output area (3); Measuring the voltage drop along the measuring section (2); and Calculate the current to be determined taking into account the voltage drop along the measuring section (3) and the resistance of the measuring section (2).

Description

shunt with areas of different density The invention relates to a shunt for measuring electrical current, wherein the shunt has an input region with at least one input contact and the shunt has an output region with at least one output contact, and wherein the shunt has at least one measuring section which is arranged between the input region and the output region. The invention also relates to a method for measuring an electric current with a shunt and to a current measuring device with a shunt. A shunt, also called a shunt resistor or current measuring resistor, is an electrical component that is used to measure electrical currents, especially larger currents, such as those in the range of over 100 amps. To do this, the current to be measured is passed through the shunt. A measuring section of the shunt has a defined resistance and by measuring the voltage drop along this measuring section, the current strength can be determined. For this purpose, the measuring section is usually made of a material with a higher resistance than the input and output areas, which should generally have the lowest possible resistance in order to keep heat production as low as possible. US 3273027 A discloses a device which has a section consisting of a hollow cylinder, wherein the cylinder is filled with a different material than its casing. This structure is complex and expensive to manufacture. Smaller shunts for low currents sometimes have measuring sections that are made of the same material as the input and output areas. However, this is no longer possible with high currents due to the heat production and losses in the input and output areas. The object of the invention is therefore to provide a shunt, a current measuring device and an above-mentioned method which can be manufactured as simply as possible and yet is as stable as possible and is suitable for measuring larger currents. This object is achieved according to the invention in that the input area, the measuring section and the output area have the same material and the measuring section has a different density than the input area and the output area. It is also solved by the fact that the procedure includes the following steps: Providing at least one shunt according to the invention or one current measuring device according to the invention; Conducting the current to be determined through the measuring section of the shunt, which has a different density than the input area and the output area; Measuring the voltage drop along the measuring section; and Calculation of the current to be determined taking into account the voltage drop along the measuring section as well as the resistance of the measuring section. The process steps can sometimes be carried out simultaneously or in a different order. Steps can also be carried out in between, before or after. The electrical resistance of the measuring section is usually known very precisely. Using Ohm's law, the current flowing can be determined by measuring the voltage drop along the measuring section. The current to be determined can be calculated using the formula I = U / R, where I is the current to be determined, U is the measured voltage drop and R is the electrical resistance of the measuring section. Density adjustment makes it possible to precisely adjust the electrical resistance of the measuring section in a particularly simple manner, regardless of the cross-sections or lengths of these components. This means that the electrical resistance can be adjusted independently of the resistances of the input and output areas, without the need to change the material. The manufacturing process only needs to be adjusted slightly to produce shunts whose measuring sections have different densities. This makes manufacturing easier. Furthermore, the inventive solution made from a single material can avoid undesirable interactions between different materials at interfaces. It is particularly advantageous if the measuring section has a lower density than the input area and the output area. The lower density of the measuring section means that the electrical resistance of the measuring section is higher than that of the output area or the input area. This means that the input and output areas have low thermal loads and low voltage drops, but the measuring section can still be made of the same material. In addition, the thermal load on the measuring section itself is lower because its surface is large. This requires a design that is easy to manufacture, but still has low thermal losses and is also suitable for measuring high currents. "Arranged between the input area and the output area" means that the measuring section is electrically connected between the input area and the output area. The current to be measured therefore flows from the input area through the measuring section to the output area. As a rule, this means that the measuring section is also spatially arranged between the input and output areas. However, curv