DE102022115523A1 - Current measuring resistor - Google Patents

Abstract

The invention relates to a current measuring resistor (1) for measuring an electrical current (I), having two plate-shaped connection parts (2, 3) made of a conductor material and a plate-shaped resistance element (4) made of a resistance material, the resistance element (4) being connected electrically and mechanically the connection parts (2, 3) and is arranged in the current flow direction between the two connection parts (2, 3), so that the electrical current (I) to be measured flows through the resistance element (4). The invention provides that the resistance element (4) is at least partially arranged between the first connection part (2) located on the top of the resistance element (4) and the second connection part (3) located on the underside of the resistance element (4).

Description

Technical field of the invention

The invention relates to a current measuring resistor (“shunt”) for measuring an electrical current.

Background of the invention

1 shows a conventional current measuring resistor 1, for example EP 0 605 800 B1 is known and is used to measure current according to four-wire technology. The known current measuring resistor 1 initially has a plate-shaped connecting part 2, which consists of a conductor material (eg copper) and serves to introduce an electrical current I to be measured into the current measuring resistor 1. In addition, the known current measuring resistor 1 has a further plate-shaped connection part 3, which also consists of a conductor material (eg copper) and serves to lead the electrical current I to be measured back out of the current measuring resistor 1. In the direction of current flow between the two connection parts 2, 3, a resistance element 4 is arranged, which consists of a resistance material (eg Manganin®, ie CuMn12Ni) and is connected to the connection parts 2, 3 at its end edges by electron beam welding. The electrical current I to be measured is therefore introduced into the current measuring resistor 1 via the connecting part 2, then flows through the resistance element 4 and is finally led out of the current measuring resistor 1 again through the connecting part 3. In addition, the current measuring resistor 1 has two voltage taps, which are not shown for simplicity and serve to measure the voltage drop across the resistance element 4. The measured voltage drop across the resistance element 4 is then, in accordance with Ohm's law, a measure of the electrical current I that flows through the current measuring resistor 1. It should also be mentioned that a hole 5 or 6 is arranged in the two connecting parts 2, 3, which makes it possible to screw the connecting parts 2 and 3, for example, to a busbar.

However, this known current measuring resistor 1 is not yet completely satisfactory. In particular, the dissipation of the electrical heat loss generated in the resistance element 4 during operation via the connecting parts 2, 3 is not yet satisfactory.

Description of the invention

The invention is therefore based on the object of creating a correspondingly improved current measuring resistor.

This object is achieved by a current measuring resistor according to the invention according to the main claim.

The current measuring resistor according to the invention initially has, in accordance with the known current measuring resistor described above, a plate-shaped first connection part, which consists of an electrically conductive conductor material (e.g. copper) and serves to introduce the electrical current to be measured into the current measuring resistor.

In addition, the current measuring resistor according to the invention, in accordance with the known current measuring resistor described above, also has a second plate-shaped connection part, which also consists of a conductor material (e.g. copper) and serves to lead the electrical current back out of the current measuring resistor.

Furthermore, the current measuring resistor according to the invention, in accordance with the prior art, comprises a resistance element made of a resistance alloy (e.g. Manganin®, i.e. CuMn12Ni), which is arranged in the direction of current flow between the two connecting parts and is thus flowed through by the electrical current to be measured during operation.

The voltage drop across the resistance element is then, in accordance with Ohm's law, a measure of the electrical current that flows through the current measuring resistor, which conventionally enables current measurement according to the known four-wire technology, as shown, for example, in EP 0 605 800 B1 is described.

In the known current measuring resistor described at the beginning, the heat dissipation of the electrical heat loss arising in the resistance element into the plate-shaped connection parts is relatively poor, since the contact surfaces between the resistance element on the one hand and the adjacent plate-shaped connection parts are relatively small, which leads to correspondingly poor heat conduction from the resistance element into the Connecting parts leads.

To avoid this disadvantage, the invention provides that the resistance element is not connected to the connecting parts at its narrow end faces, but instead is sandwiched lies nicely between the connecting parts. The resistance element is therefore at least partially arranged between the first connection part located on the top of the resistance element and the second connection part located on the underside of the resistance element. This sandwich-shaped arrangement of the current measuring resistor according to the invention advantageously enables a significantly larger contact area between the resistance element on the one hand and the connection parts on the other hand, which in turn enables good heat dissipation of the electrical heat loss generated in the resistance element into the connection parts.

In a variant of the invention, the resistance element completely overlaps with the first connection part, so that the first connection part completely covers the top side of the resistance element. In the same way, there is also the possibility that the resistance element completely overlaps with the second connection part, so that the second connection part completely covers the underside of the resistance element from below. The resistance element is completely covered by the connecting parts at the bottom and/or top.

In this variant of the invention, it is possible for the two connecting parts to be flush with one side of the resistance element in the direction of current flow, i.e. the connecting parts do not protrude beyond the resistance element in the direction of current flow or only in one direction, namely for current introduction or current output.

However, in this variant of the invention, there is also the alternative possibility that the connecting parts protrude beyond the resistance element in the direction of current flow, namely in both directions.

In another variant of the invention, however, the resistance element only partially overlaps with the first connection part or the second connection part. This means that part of the top of the resistance element is exposed, while another part of the top of the resistance element is covered by the first connection part. For the underside of the current measuring resistor, a part of the underside of the resistance element is exposed, while the remaining part of the underside of the resistance element is covered by the second connection part.

In general, it should be mentioned that the resistance element and the two connecting parts can be arranged plane-parallel to one another.

• • Quader,
• • Zylinder,
• • Hohlzylinder,
• • Kreisscheibe,
• • Prisma.

With regard to the shape of the resistance element, there are many possibilities within the scope of the invention. For example, the resistance element can have one of the following forms:

• • cuboid,
• • cylinder,
• • hollow cylinder,
• • circular disk,
• • Prism.

It has already been mentioned above that the two plate-shaped connecting parts have the task of introducing the electrical current to be measured into the current measuring resistor or leading it out of the current measuring resistor. In a variant of the invention, the two connecting parts protrude from the resistance element in the same direction, so that the current measuring resistor is U-shaped in a side view. In another variant of the invention, however, the two connecting parts protrude from the resistance element in opposite directions, so that the current measuring resistor is Z-shaped in the side view.

In addition, it should be mentioned that the connecting parts of the current measuring resistor can enclose an angle in a top view of the current measuring resistor, which can be, for example, 90 °, so that the current measuring resistor is L-shaped when viewed from above, with the two connecting parts then each having a leg of the Form L shape.

Alternatively, it is also possible for the connecting parts to enclose an angle in a top view of the current measuring resistor, which can be, for example, 30°, so that the current measuring resistor is V-shaped when viewed from above, with the two connecting parts each forming a leg of the V shape .

In another variant, however, the connecting parts enclose an angle in a top view of the current measuring resistor that is essentially 0°, so that the current measuring resistor is U-shaped in the side view. The connecting parts protrude from the resistance element in the same direction.

Alternatively, there is also the possibility that the connecting parts enclose an angle in a top view of the current measuring resistor that is essentially 180°, as is the case with the conventional current measuring resistor described at the beginning. The connection parts and the resistance element are in one line.

In addition, the current measuring resistor according to the invention can have two voltage taps that act on the two connecting parts in order to measure the voltage drop across the resistance element. According to Ohm's law, the voltage drop across the resistance element is then a measure of the electrical current that flows through the current measuring resistor.

Optionally, there is also the possibility of a third voltage tap, which acts on the resistance element and thus forms a center tap.

There are various options within the scope of the invention with regard to the spatial arrangement of the voltage taps. In a variant of the invention, the two voltage taps are located on the top side of the first connection part or on the underside of the second connection part, i.e. on the side of the respective connection part that faces away from the resistance element.

Alternatively, however, there is also the possibility that the voltage taps are each arranged on the narrow side edges of the connecting parts or the resistance element.

In a further development of the invention, the connecting parts can each be connected to a busbar, the connection being able to be made, for example, by a rivet.

The invention enables a variety of designs and designs. For example, the current measuring resistor can have the shape of a thin cuboid, with a central hole passing from the top to the bottom of the current measuring resistor in order to adjust the resistance value.

In addition, the connection parts can each have an exemption, as is known from the prior art and is also referred to as a current shadow. In a variant of such a current shadow, the exemption is an incision that runs from the top to the bottom and therefore completely prevents current flow across the incision. In another variant, however, the exemption is a groove on the top and/or on the bottom, which makes it more difficult for current to flow across the groove because the material cross section is reduced in the area of the groove.

Furthermore, within the scope of the invention there is the possibility that the connecting parts have an exemption that is used for fastening, for example by means of a rivet, a screw or a clinching connection (e.g. TOX®-eClinch connection).

There are various options within the scope of the invention with regard to the width of the connection parts and the resistance element transversely to the direction of current flow. For example, the two connection parts and the resistance element can all have the same width. Alternatively, it is possible for the connecting parts to have different widths. In addition, there is also the possibility that at least one of the connection parts has a different width than the resistance element.

• • Lötverbindung, insbesondere Weichlötverbindung oder Hartlötverbindung,
• • Press-Sinterverbindung, optional mit Kupfer oder Silber als Sintermaterial, optional mit einer Nanostrukturierung der Kontaktflächen des Widerstandselements und/oder der Anschlussteile,
• • Press-Klebeverbindung, optional mit einem Epoxidkleber, optional mit einer Nanostrukturierung der Kontaktflächen des Widerstandselements und/oder der Anschlussteile,
• • Schweißverbindung, insbesondere eine Punktschweißverbindung oder eine Laserschweißverbindung,
• • Nietverbindung,
• • Schraubverbindung,
• • Durchsetzfügeverbindung, insbesondere durch eine TOX®-eClinch-Verbindung.

It should also be mentioned that the resistance element can be connected to the connection parts, for example, by one of the following connections:

• • Solder connection, especially soft solder connection or hard solder connection,
• • Press-sinter connection, optionally with copper or silver as sintered material, optionally with nanostructuring of the contact surfaces of the resistance element and/or the connecting parts,
• • Press-adhesive connection, optionally with an epoxy adhesive, optionally with nanostructuring of the contact surfaces of the resistance element and/or the connecting parts,
• • Welded connection, in particular a spot welded connection or a laser welded connection,
• • rivet connection,
• • screw connection,
• • Reinforced joint connection, especially through a TOX®-eClinch connection.

However, with regard to the type of connection between the resistance element and the connection parts, the invention is not limited to the connection types mentioned above as examples.

Furthermore, within the scope of the invention there is the possibility that the resistance element is connected to the connection parts in the entire overlap area. This is advantageous because the contact area between the resistance element and the connecting parts is then maximum, which also contributes to optimizing heat dissipation.

Alternatively, however, there is also the possibility that the resistance element is only connected to the connection parts in a part of the overlap area, in particular only at certain points. For example, such a spatially limited invention can be achieved by a spot welding method binding, a rivet connection or a clinch connection.

It should also be mentioned that the resistance element in the overlap area with the connection parts can be coated on its underside with a coating in order to improve the adhesion of the resistance element to the connection parts. For example, this coating can have a layer thickness of at least 1 µm, 2 µm, 5 µm, 10 µm, 20 µm and/or at most 500 µm, 250 µm, 100 µm. It should also be mentioned that the coating can contain copper, nickel, silver, titanium and/or chromium.

It was already mentioned at the beginning that the conductor material of the connecting parts can be copper. However, the invention is not limited to copper with regard to the conductor material of the connecting parts, but can also be implemented, for example, with a copper alloy, aluminum or an aluminum alloy.

However, the conductor material of the connecting parts should have a smaller specific electrical resistance than the resistance material of the resistance element.

Regarding the current measuring resistor, it should be mentioned in general that the current measuring resistor is preferably low-resistance. This means that the current measuring resistor preferably has a small resistance value, which is preferably smaller than 50 µΩ, 100 µΩ, 250 µΩ, 500 µΩ, 1 mS2, 10 mS2, 50 mΩ or 100 mΩ.

There are various options within the scope of the invention with regard to the resistance material of the resistance element. For example, the resistance material can be a copper-manganese-nickel alloy, such as Manganin®, i.e. CuMn12Ni. Alternatively, there is also the possibility that the resistance material is a nickel-chrome alloy, such as ISAOHM® (i.e. NiCr20AlSi). There is also the possibility that the resistance material is a copper-manganese alloy or a copper-nickel alloy. However, the invention is not limited to the above examples of resistance materials.

However, the resistance material should have a small specific electrical resistance, which is preferably less than 10,000 µΩcm, 1,000 µΩcm or 500 µΩcm.

Furthermore, it should be mentioned that the resistance element preferably has a thickness that is at least 0.5 mm, 1 mm, 2 mm or 3 mm.

To further improve the dissipation of heat loss, the resistance element in the current measuring resistor according to the invention can be connected to a heat transfer element, such as a so-called heat pipe.

Regarding the current measuring resistor, it should also generally be mentioned that the current measuring resistor preferably has a current carrying capacity of at least 10 A, 50 A, 100 A, 200 A, 500 A or 1 kA under continuous load.

The current measuring resistor according to the invention was described above as a single component. However, the invention also claims protection for a current measuring device with such a current measuring resistor and a voltage measuring device for measuring the voltage drop across the resistance element of the current measuring resistor.

In a preferred embodiment of the invention, the voltage measuring device has two measuring channels in order to measure two different voltage drops at two pairs of voltage taps on the current measuring resistor.

In a variant of the invention, the two measuring channels of the voltage measuring device are connected to the pairs of voltage taps in such a way that the voltage drops are measured crosswise, as shown, for example DE 10 2021 103 241.5 is known.

In another variant of the invention, however, the two measuring channels are connected to the voltage taps in such a way that the voltage drops are measured in parallel next to each other, as shown, for example WO 2014/161624 A1 is known.

In another variant of the invention, the voltage measuring device has three measuring channels which measure three voltage drops at three voltage taps. The three voltage taps form a closed mesh over the resistance element, for example DE 20 2021 105 281 U1 is known.

Other advantageous developments of the invention are characterized in the subclaims or are explained in more detail below together with the description of the preferred exemplary embodiments of the invention with reference to the figures.

Brief description of the drawings

• 1 shows a perspective view of a conventional current measuring resistor according to the prior art.
• 2 shows a perspective view of an exemplary embodiment of a current measuring resistor according to the invention.
• 3 shows a perspective view of a further embodiment of a current measuring resistor according to the invention.
• 4 shows a schematic side view of the current measuring resistor according to 2 .
• 5 shows a schematic side view of the current measuring resistor according to 3 with an additional voltage measuring device.
• 6 shows a modified embodiment of the current measuring resistor according to 2 and 4 .
• 7 shows a further modification of a current measuring resistor according to the invention.
• 8th shows a schematic top view of the current measuring resistor according to the invention 3 .
• 9 shows a schematic top view of a modified embodiment of a current measuring resistor according to the invention.
• 10 shows a modification, whereby the current measuring resistor is V-shaped when viewed from above.
• 11 shows a modification of the current measuring resistor according to 10 with an additional through hole.
• 12 shows another embodiment with a through hole.
• 13 and 14 show different views of the current measuring resistor according to 12 with two power rails.

Detailed description of the drawings

The following will now be the in 2 illustrated embodiment of a current measuring resistor 1 according to the invention is described, which is partly similar to that described at the beginning and in 1 conventional current measuring resistor 1 shown corresponds, so that to avoid repetition, reference is made to the above description, the same reference numbers being used for corresponding details.

A special feature of this exemplary embodiment is that the resistance element 4 is not connected to the connecting parts 2, 3 with its narrow end faces. Instead, the resistance element 4 is sandwiched between the two connection parts 2, 3. This is advantageous because the contact area between the resistance element 4 on the one hand and the connecting parts 2, 3 on the other hand is significantly larger than in the case described above and in 1 conventional current measuring resistor 1 shown. This enlarged contact area in turn leads to improved heat dissipation from the resistance element 4 into the connecting parts 2, 3.

In this exemplary embodiment, the resistance element 4 completely overlaps with the connection parts 2, 3. This means that the resistance element 4 is completely covered on its top by the connection part 2. Accordingly, the resistance element 4 is completely covered on its underside by the connecting part 3.

3 shows a modification of the current measuring resistor 1 according to the invention 2 , so that to avoid repetition, reference is made to the above description, with the same reference numbers being used for corresponding details.

A special feature of this exemplary embodiment is that the resistance element 4 does not completely overlap with the two connection parts 2, 3. Thus, the resistance element 4 only partially overlaps the connecting part 2 on its upper side, so that part of the upper side of the resistance element 4 is exposed, while the remaining part of the upper side of the resistance element 4 is covered by the connecting part 2. In the same way, the resistance element 4 only partially overlaps the connection part 3 on its underside, so that part of the underside of the resistance element 4 is exposed, while the remaining part of the underside of the resistance element 4 is covered from below by the connection part 3.

4 shows a schematic side view of the current measuring resistor 1 according to 2 .

From this side view it can be seen that a coating 7, 8 is arranged between the resistance element 4 and the two connection parts 2, 3, the coatings 7, 8 being merely optional. The coatings 7, 8 can improve the adhesion of the resistance element 4 to the connecting parts 2, 3.

5 shows a schematic side view of the current measuring resistor 1 according to 3 , so that to avoid repetition, reference is made again to the above description, with the same reference numbers being used for corresponding details.

The drawing also shows two voltage taps 9, 10, which act on the connecting part 2 and the connecting part 3, respectively. It should be mentioned here that the two voltage taps 9, 10 each act on the outside of the two connection parts 2, 3, ie on the side that faces away from the resistance element 4.

Furthermore, a voltage measuring device 11 is shown here, which is connected to the two voltage taps 9, 10 and measures the voltage drop across the resistance element 4, this voltage drop being a measure of the electrical current I that flows through the current measuring resistor 1 in accordance with Ohm's law.

6 shows a further exemplary embodiment of a current measuring resistor 1 according to the invention, which partially corresponds to the exemplary embodiments described above, so that reference is made to the above description to avoid repetition.

A special feature compared to the exemplary embodiment 4 is that the two connecting parts 2, 3 protrude beyond the resistance element 4 on both sides in the direction of current flow.

A special feature compared to the exemplary embodiment 5 is that the voltage taps 9, 10 each engage the insides of the connecting parts 2, 3, ie on the sides that face the resistance element 4.

7 shows a further exemplary embodiment of a current measuring resistor 1 according to the invention, which partially corresponds to the exemplary embodiments described above, so that to avoid repetition, reference is made to the above description, the same reference numbers being used for corresponding details.

A special feature of this exemplary embodiment is that a center tap is provided, which consists of a further voltage tap 12 on the resistance element 4.

In addition, two further voltage measuring devices 13, 14 are provided, so that the voltage measuring devices 11, 13 and 14 measure three voltages U ₁₃ , U ₁₂ , U ₂₃ along a closed mesh.

The 8th and 9 show a schematic top view of two exemplary embodiments of a current measuring resistor 1 according to the invention. In the exemplary embodiment according to 8th the connecting parts 2, 3 and the resistance element 4 all have the same width transverse to the direction of current flow b _A1 =b _A2 =b _W.

In the exemplary embodiment according to 9 On the other hand, the connecting part 2 has a smaller width b _A1 than the connecting part 3 and the resistance element 4 with b _A2 >b _A1 and b _W >b _A1 .

10 shows a schematic top view of a further exemplary embodiment of a current measuring resistor 1 according to the invention, which again partially corresponds to the exemplary embodiments described above.

A special feature here is that the two connecting parts 2, 3 enclose an angle α≅30°, so that the current measuring resistor 1 is V-shaped when viewed from above.

The exemplary embodiment according to 11 largely agrees with the exemplary embodiment 10 agree. A special feature here is that a hole 15 passes through the entire current measuring resistor 1. The hole 15 can also serve to adjust the resistance value of the current measuring resistor 1.

12 shows a further exemplary embodiment of a current measuring resistor according to the invention, which partially corresponds to the exemplary embodiments described above, so that to avoid repetition, reference is made to the above description, the same reference numbers being used for corresponding details.

A special feature here is that contact tags 16, 17 are molded onto the two connecting parts 2, 3.

Another special feature is the continuous bore 15.

Finally they show 13 and 14 different views of the current measuring resistor 1 according to 12 with two busbars 18, 19, which are connected to the current measuring resistor 1 by a rivet 20. The rivet 20 can pass through the holes 15 in the current measuring resistor individually.

The invention is not limited to the preferred embodiments described above. Rather, the invention includes a large number of variants and modifications that also make use of the inventive idea and therefore fall within the scope of protection. In particular, the invention also claims Protection for the subject matter and the features of the subclaims regardless of the claims referred to and in particular without the features of the main claim. The invention therefore encompasses various aspects of the invention, which enjoy protection independently of one another.

Advantages of the invention

• • Durch die Sandwichbauweise bestehen weitere Konstruktionsfreiheitsgrade:
  • • Der Widerstandswert kann für eine große Bandbreite von spezifischen Widerständen eingestellt werden.
  • • Der effektive, gemessene Widerstandswert ist variabel einstellbar durch eine Positionierung der Spannungsabgriffe entlang und quer zur Stromflussrichtung.
  • • Der Temperaturkoeffizient des elektrischen Widerstands (TCR: Temperature coefficient of resistance) ist ebenfalls einstellbar durch Freistellungen und Positionierung der Spannungsabgriffe entlang und quer zur Stromflussrichtung.
  • • Freistellungen sind nutzbar für eine zusätzliche mechanische Befestigung.
  • • Es ist eine neue und weniger komplexe Aufbau- und Verbindungstechnik möglich durch Stapeln, dann Löten, Press-Sintern oder Press-Kleben (optional dabei Erwärmen) und optional durch zusätzliches Einbringen einer Befestigung (Niet, Clinch-Punkt).
  • • Es sind mehr Freiheitsgrade für die Anbindung des Strommesswiderstands auf Kundenseite möglich. Die Anschlussteile können flexibel auf Kundenwunsch designt werden und einen Winkel von 0° bis 360° zueinander einschließen und somit flexibel an die Einbaugeometrie des Kunden angepasst werden.
• • Es erfolgt eine bessere intrinsische Wärmeabfuhr durch die größere Kontaktfläche von Widerstandselement einerseits und Anschlussteilen andererseits.
• • Der erfindungsgemäße Strommesswiderstand hat eine bessere Langzeitstabilität durch:
  • • Weniger Oberfläche des Widerstandselements ist der Oxidation ausgesetzt.
  • • Anwendbarkeit der Widerstandslegierung ISAOHM® ist gegeben aufgrund der höheren Konstruktionsfreiheitsgrade.

The invention offers, among other things, the following advantages:

• • The sandwich construction offers additional degrees of design freedom:
  • • The resistance value can be adjusted for a wide range of specific resistances.
  • • The effective, measured resistance value can be variably adjusted by positioning the voltage taps along and across the direction of current flow.
  • • The temperature coefficient of electrical resistance (TCR: Temperature coefficient of resistance) can also be adjusted by releasing and positioning the voltage taps along and across the direction of current flow.
  • • Releases can be used for additional mechanical fastening.
  • • A new and less complex assembly and connection technology is possible by stacking, then soldering, press-sintering or press-gluing (optionally heating) and optionally by additionally introducing a fastener (rivet, clinch point).
  • • More degrees of freedom are possible for connecting the current measuring resistor on the customer side. The connecting parts can be designed flexibly according to customer requirements and include an angle of 0° to 360° to each other and can therefore be flexibly adapted to the customer's installation geometry.
• • There is better intrinsic heat dissipation due to the larger contact area between the resistance element on the one hand and the connecting parts on the other.
• • The current measuring resistor according to the invention has better long-term stability due to:
  • • Less surface area of the resistance element is exposed to oxidation.
  • • The resistance alloy ISAOHM® can be used due to the higher degrees of design freedom.

Reference symbol list

1

Current measuring resistor

2

Connection part for introducing the current into the current measuring resistor

3

Connection part for discharging the current from the current measuring resistor

4

resistance element

5

Hole in the connecting part for introducing the current into the current measuring resistor

6

Hole in the connecting part for discharging the current from the current measuring resistor

7

Coating between the resistance element and the connecting part for introducing the current into the current measuring resistor

8th

Coating between the resistance element and the current measuring resistor for discharging the current from it

9

Voltage tap on the connecting part for introducing the current into the current measuring resistor

10

Voltage tap on the to drain the current from the current measuring resistor

11

Voltage measuring device

13, 14

Voltage measuring device

12

Voltage tap on the resistance element

15

Hole through the current measuring resistor

16

Contact flags on the connection part for introducing the current

17

Contact flags on the connecting part for discharging the current

18

Busbar for introducing the current into the current measuring resistor

19

Busbar for discharging the current from the current measuring resistor

20

Rivet for connecting the busbars to the current measuring resistor

bA1

Width of the connecting part for introducing the current into the current measuring resistor

bA2

Width of the connection part for discharging the current from the current measuring resistor

bW

Width of the resistance element

I

Current through the current measuring resistor

U12

Voltage between resistance element and the connecting part for introducing the current into the current measuring resistor

U23

Voltage between the resistance element and the connecting part for discharging the current from the current measuring resistor

U13

Voltage between the two connecting parts

α

Angle between the connecting parts

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0605800 B1 [0002, 0009]
• DE 102021103241 [0047]
• WO 2014/161624 A1 [0048]
• DE 202021105281 U1 [0049]

Claims (22)

Current measuring resistor (1) for measuring an electrical current (I), with a) a plate-shaped first connection part (2) made of an electrically conductive conductor material, in particular for introducing the current (I) to be measured into the current measuring resistor (1), b) a plate-shaped second connection part (3) made of an electrically conductive conductor material, in particular for discharging the current (I) to be measured from the current measuring resistor (1), and c) a plate-shaped resistance element (4) made of a low-resistance resistance material, wherein the resistance element (4) is electrical and mechanically connected to the connection parts (2, 3) and arranged in the current flow direction between the two connection parts (2, 3), so that the electrical current (I) to be measured flows through the resistance element (4), characterized in that d) that Resistance element (4) is at least partially arranged between the first connection part (2) located on the top of the resistance element (4) and the second connection part (3) located on the underside of the resistance element (4). Current measuring resistor (1). Claim 1 , characterized in a) that the resistance element (4) completely overlaps with the first connection part (2), so that the first connection part (2) completely covers the top of the resistance element (4), and / or b) that the resistance element (4 ) completely overlaps with the second connection part (3), so that the second connection part (3) completely covers the underside of the resistance element (4) from below. Current measuring resistor (1). Claim 2 , characterized in that a) that the first connection part (2) projects beyond the resistance element (4) on both sides in the current flow direction, and / or b) that the second connection part (3) projects beyond the resistance element (4) on both sides in the current flow direction. Current measuring resistor (1). Claim 1 , characterized in a) that the resistance element (4) only partially overlaps with the first connection part (2), so that the top of the resistance element (4) is only partially covered by the first connection part (2), and / or b) that the resistance element (4) only partially overlaps with the second connection part (3), so that the underside of the resistance element (4) is only partially covered by the second connection part (3). Current measuring resistor (1) according to one of the preceding claims, characterized in that the resistance element (4) and the two connecting parts (2, 3) are arranged plane-parallel to one another. Current measuring resistor (1) according to one of the preceding claims, characterized in that the resistance element (4) has one of the following shapes: a) cuboid, b) cylinder c) hollow cylinder, d) circular disk, e) prism. Current measuring resistor (1) according to one of the preceding claims, characterized in that a) that the current measuring resistor (1) is U-shaped in a side view, so that the two connecting parts (2, 3) protrude from the resistance element (4) in the same direction , or b) that the current measuring resistor (1) is Z-shaped in a side view, so that the two connecting parts (2, 3) protrude from the resistance element (4) in opposite directions. Current measuring resistor (1) according to one of the preceding claims, characterized in that a) that the connecting parts (2, 3) in a top view of the current measuring resistor (1) enclose an angle (α) which is essentially 90 °, with deviations from a maximum ±15°, ±10°, ±5° or ±2°, so that the current measuring resistor (1) is L-shaped when viewed from above, or b) that the connecting parts (2, 3) are viewed from above on the current measuring resistor (1 ) include an angle (α) that is between 15° and 60° or between 25° and 45°, in particular 30°, so that the current measuring resistor (1) is V-shaped when viewed from above, or c) that the connecting parts ( 2, 3) in a top view of the current measuring resistor (1) include an angle that is essentially 0°, with deviations of a maximum of ±15°, ±10°, ±5° or ±2°, so that the current measuring resistor (1 ) is Z-shaped in the side view, or d) that the connecting parts (2, 3) in a top view of the current measuring resistor (1) enclose an angle that is essentially 180 °, so that the current measuring resistor (1) in the side view is U-shaped. Current measuring resistor (1) according to one of the preceding claims, characterized in that a) that the current measuring resistor (1) has a first voltage tap (9) on the first connecting part (2), b) that the current measuring resistor (1) has a second voltage tap (10) on the second connection part (3), c) that the current measuring resistor (1) optionally has a third voltage tap (12) on the resistance element (4). , especially when the resistance element (4) only partially overlaps with the connecting parts (2, 3). Current measuring resistor (1). Claim 9 , characterized in that a) the first voltage tap (9) is arranged on the first connection part (2) on the top side of the first connection part (2) facing away from the resistance element (4), and b) that the second voltage tap (10) on the second connection part (3) is arranged on the underside of the second connection part (3) facing away from the resistance element (4). Current measuring resistor (1). Claim 9 , characterized in a) that the first voltage tap (9) is arranged on a side edge of the first connection part (2), b) that the second voltage tap (10) is arranged on a side edge of the second connection part (3), and / or c ) that the optional third voltage tap is arranged on a side edge of the resistance element (4). Current measuring resistor (1) according to one of the preceding claims, characterized in that a) that the first connecting part (2) is electrically and mechanically connected on its top to a first busbar (18), in particular by a rivet, and b) that the second connecting part (3) is electrically and mechanically connected on its underside to a second busbar (19), in particular by a rivet. Current measuring resistor (1) according to one of the preceding claims, characterized in that a) that the current measuring resistor (1) has the shape of a cuboid, a prism or a circular disk, and b) that through the current measuring resistor (1) there is a central bore (15) from the Top goes through to the bottom. Current measuring resistor (1) according to one of the preceding claims, characterized in that the first connection part (2) and / or the second connection part (3) has an exemption, in particular a) as an incision that goes through from the top to the bottom and a current flow across via the incision, or b) as a groove on the top or bottom, which makes it difficult for current to flow across the groove. Current measuring resistor (1) according to one of the preceding claims, characterized in that the first connection part (2) and/or the second connection part (3) has an exemption, the exemption serves for fastening, in particular by means of a) rivet (20), b) Screw, c) clinching joint, in particular through a TOX®-eClinch connection. Current measuring resistor (1) according to one of the preceding claims, characterized in that a) that the first connecting part (2) has the same width (b _A1 ) as the resistance element (4) or a different width transversely to the direction of current flow, and / or b) that second connection part (3) has the same width (b _A2 ) transversely to the direction of current flow as the resistance element (4) or a different width, and / or c) that the first connection part (2) has the same width (b _A1 ) as that transverse to the direction of current flow second connection part (3) or a different width. Current measuring resistor (1) according to one of the preceding claims, characterized in that the resistance element (4) is connected to the connecting parts (2, 3) by one of the following types of connection: a) solder connection, in particular soft solder connection or hard solder connection, b) press-sinter connection, optionally with copper or silver as sintered material, optionally with a nanostructuring of the contact surfaces of the resistance element (4) and/or the connecting parts (2, 3), c) press-adhesive connection, optionally with an epoxy adhesive, optionally with a nanostructuring of the contact surfaces of the resistance element ( 4) and/or the connecting parts (2, 3), d) welded connection, in particular a spot welded connection or a laser welded connection, e) rivet connection, f) screw connection, g) clinching connection, in particular by a TOX®-eClinch connection. Current measuring resistor (1) according to one of the preceding claims, characterized in that a) that the resistance element (4) in the entire overlap area with the connection share (2, 3) is connected, and / or b) that the resistance element (4) is connected to the connecting parts (2, 3) only within a part of the overlap area, in particular only at points, in particular by b1) a spot welded connection, b2 ) a rivet connection or b3) a clinch connection. Current measuring resistor (1) according to one of the preceding claims, characterized in that a) that the resistance element (4) is coated on its underside with a coating (7, 8) in the overlap area with the connecting parts (2, 3) in order to ensure the adhesion of the To improve the resistance element (4) on the connecting parts (2, 3), b) that the coating (7, 8) optionally has a layer thickness of at least 1 µm, 2 µm, 5 µm, 10 µm, 20 µm and/or a maximum of 500 µm , 250 µm, 100 µm, c) that the coating (7, 8) optionally contains copper, nickel, silver, titanium and / or chromium. Current measuring resistor (1) according to one of the preceding claims, characterized in that a) that the conductor material of the connecting parts (2, 3) is copper, a copper alloy, aluminum or an aluminum alloy, and / or b) that the conductor material of the connecting parts (2, 3 ) has a smaller specific electrical resistance than the resistance material of the resistance element (4), and / or c) that the current measuring resistor (1) has a resistance value that is smaller than 50 µΩ, 100 µΩ, 250 µΩ, 500 µΩ, 1 mS2, 10 mS2, 50 mΩ or 100 mS2, and/or d) that the resistance material is one of the following alloys: d1) nickel-chromium alloy, in particular NiCr20AlSi, d2) copper-manganese alloy, d3) copper-manganese-nickel Alloy, d4) copper-nickel alloy, and / or e) that the resistance material of the resistance element (4) has a specific electrical resistance that is smaller than 10000 µΩcm, 1000 µΩcm or 500 µΩcm, and / or f) that the resistance material the resistance element (4) has a thickness that is at least 0.5 mm, 1 mm, 2mm or 3mm, and/or g) that the resistance element (4) is connected to a heat transfer element, in particular to a heat pipe, in order to dissipate lost heat, and/or h) that the current measuring resistor (1) has a current carrying capacity of at least 10 A, 50A, 100A, 200 A, 500A or 1 kA under continuous load. Current measuring device with a) a current measuring resistor (1) according to one of the preceding claims, and b) a voltage measuring device (11; 13, 14) for measuring the voltage drop across the resistance element (4) of the current measuring resistor (1). Current measuring device Claim 21 , characterized in a) that the current measuring resistor (1) has at least two voltage taps (9, 10, 12), b) that the first voltage tap (9) acts on the first connection part (2), c) that the second voltage tap (10 ) acts on the second connection part (3), and d) that the optional third voltage tap (12) acts on the resistance element (4), e) that the voltage measuring device (11, 13, 14) has at least one measuring channel, f) that a Measuring channel of the voltage measuring device (11, 13, 14) measures the voltage (U ₁₃ ) between the first voltage tap (9) and the second voltage tap (10), and / or g) that a measuring channel of the voltage measuring device (11, 13, 14) the Voltage (U ₁₂ ) between the first voltage tap (9) and the third voltage tap (12) measures, and / or h) that a measuring channel of the voltage measuring device (11, 13, 14) measures the voltage (U ₂₃ ) between the second voltage tap (10 ) and the third voltage tap (12).

Images