Device for temperature measurement and device for current determination

Abstract

The invention describes a device for temperature measurement, having a circuit board (2) and a temperature sensor (3), wherein the circuit board (2) has a milled groove (4) which extends substantially helically around the temperature sensor (3) such that the temperature sensor (3) can be displaced parallel to a normal vector of a plane of the circuit board (2) and, in the event of a displacement of the temperature sensor (3) relative to the plane of the circuit board (2), a resetting force acts between the circuit board (2) and the temperature sensor (3). The device can in particular be part of a current-sense device by a shunt and can determine the temperature of the shunt. Furthermore, a power converter having such a device is described.

Description

Technical Field

[0001] The present invention relates to a device for temperature measurement, a device for current determination having a temperature measurement component, and an electric power converter having a current determination component. Background Technology

[0002] Accurate measurement of an object's temperature using a temperature sensor, such as a temperature-dependent resistor, generally requires good thermal contact between the temperature sensor and the object being measured. Here, the temperature sensor and associated analytical processing electronics can be arranged on a circuit board such that the temperature sensor is positioned between the circuit board and the surface of the object being measured during operation. However, this arrangement results in the circuit board itself being spaced apart from the surface at least by the structural height of the temperature sensor.

[0003] To accurately determine current, especially high currents in the range of several thousand amperes, low-ohmic measuring resistors, so-called shunts, can be used. For example, a measuring assembly for measuring current is known from DE 10 2016 010 012 B4, wherein paired voltage taps measure the voltage drop across a resistive element, and the measuring circuit, according to Ohm's law, determines a measure of the current flowing through the resistive element from the dropped voltage and the resistance value of the resistive element. Here, the resistance value of the resistive element is temperature-dependent, such that a temperature sensor is arranged on the resistive element, and the measuring circuit adjusts the resistance value used to determine the current intensity according to the temperature measured by the temperature sensor.

[0004] Especially if the resistive element is made of a common material, such as copper, which has very good conductivity but whose conductivity is strongly dependent on temperature, then it is necessary to measure the temperature of the resistive material precisely where a relevant voltage drop also occurs. Although the known arrangement of the temperature sensor on the side of the circuit board facing the resistive element enables a good thermal connection with the resistive element, it results in a gap between the circuit board and the resistive element that is at least on the order of the structural height of the temperature sensor.

[0005] Additionally, it is worthwhile to arrange the connection between the voltage tap and the measuring circuit very closely on the resistive element, especially to avoid conductor loops. Conductor loops can cause significant damage or distortion to the measurement, particularly near high currents, due to electromagnetic effects, especially when the current contains periodic or transient components.

[0006] To avoid such a conductor loop, one possibility is to place the temperature sensor on the side of the circuit board away from the resistive element, so that the circuit board with the connection between the voltage tap and the measurement circuit can be arranged as close as possible to the resistive element. However, this increases the thermal resistance between the temperature sensor and the busbar, because heat flows from the resistive element into the circuit board first and must penetrate the circuit board.

[0007] Another possibility is to mount the temperature sensor on the side of the shunt opposite the circuit board, see again DE 10 2016 010 012 B4. However, this requires an additional connection between the temperature sensor and the measurement circuitry, which extends beyond the circuit board and incurs additional installation costs. Furthermore, for sufficiently accurate temperature measurement, a certain clamping pressure is required between the temperature sensor and the surface to be measured; however, this clamping pressure must not be excessive to avoid damaging the temperature sensor.

[0008] An electrical connection assembly is known from DE 10 2011 004 174 A1, wherein a circuit board has a highly flexible circuit board area in which electronic structural elements can be arranged. Here, the structural elements are mechanically connected to and thus fixed in place by functional units, wherein the mechanical connection with the functional units can be improved by additional spring elements between the circuit board and the structural elements. Summary of the Invention

[0009] The objective of this invention is to provide a device for temperature measurement that ensures good thermal contact between a temperature sensor and the surface of the object to be measured, and to elucidate a device for current determination in which the voltage drop across a resistive element having a temperature-dependent resistance value can be measured without interference, wherein the current is determined from the voltage drop and the resistance value, which is adjusted by means of a precise measurement of the temperature of the resistive element.

[0010] Solution

[0011] This task is accomplished by a device for temperature measurement having the features of claim 1, or by a device for current determination having the features of independent claim 14, and a power converter according to claim 22. Preferred embodiments are defined in the dependent claims.

[0012] Description of the present invention

[0013] The device for temperature measurement includes a circuit board, an analysis and processing unit, and a temperature sensor. The circuit board has milled grooves... Essentially, it extends spirally around the temperature sensor, allowing the sensor to be positioned on the circuit board platform and shifted parallel to the normal vector of the circuit board plane. When the temperature sensor shifts relative to the plane of the circuit board, a restoring force acts between the circuit board and the temperature sensor.

[0014] The device for temperature measurement is particularly advantageously suited for direct placement on the surface of an object whose temperature is to be detected by a temperature sensor. The temperature sensor can be positioned on a circuit board platform such that the platform is located at the center of a helical milled groove and thus at the inner end of a verbleibend circuit board tab formed by the groove. When the circuit board is placed flush with the surface of the object to be measured, with the temperature sensor between the circuit board and the surface, the circuit board platform is pressed out of the plane of the circuit board at the structural height of the temperature sensor, so that not only the circuit board itself but also the temperature sensor can rest against the surface. This is especially convenient for mounting the device for temperature detection on the surface of the object to be measured.

[0015] The temperature sensor is preferably spring-loaded by residual circuit board tabs between coils in a helical milled groove. If the circuit board platform moves out of the plane of the circuit board, the same helical residual circuit board tabs generate a spring-loaded effect acting on the circuit board platform and thus on the temperature sensor. This is particularly achieved when the circuit board is planarly placed on the surface of the object to be measured, and the milled grooves extending around the temperature sensor ensure height compensation, such that the temperature sensor shifts parallel to the normal vector of the circuit board plane. Here, the temperature sensor can be shifted by a spring-loaded distance, which at least includes the structural height of the temperature sensor.

[0016] The milled grooves in the circuit board can preferably extend along a continuous helical shape. Here, the helical rotation can include multiple substantially straight segments and changes in direction between said segments, wherein the changes in direction particularly achieve substantially right angles between said segments; here, the changes in direction themselves can be continuous, i.e., for example, having a quarter circle. In particular, continuous helical shapes can be manufactured particularly easily in one go and have a reproducible restoring force when the circuit board platform is moved out of the circuit board plane.

[0017] The milled groove can be configured such that the radius vector of the groove's trajectory covers an angle of at least 600 degrees, preferably at least 700 degrees, such that the remaining circuit board tabs encircle the temperature sensor at least three-quarters of a turn, preferably at least one turn. This causes the circuit board platform to shift out of the circuit board plane at the structural height of the temperature sensor, resulting in elastic deformation of the remaining circuit board tabs. This elastic deformation is less than the limit of plastic deformation of the circuit board material, so that the restoring force of the circuit board tabs is permanently maintained and not significantly weakened even under temperatures above 100 degrees Celsius.

[0018] In a configuration with straight segments, the number of straight segments can be chosen such that the sum of the angles of directional changes between the straight segments reaches the aforementioned degree. Therefore, for example, in the case of right-angle directional changes, more than six segments can be provided.

[0019] In one embodiment of the device, the width of the circuit board tab, the width of the milled groove, and the length of the milled groove can be designed such that when the temperature sensor (Temperaturfühler) shifts with respect to its structural height along its normal vector parallel to the plane of the circuit board, the restoring force between the circuit board and the temperature sensor is between 0.1 Newtons and 10 Newtons, preferably between 1 Newton and 5 Newtons. Thus, when the circuit board and the temperature sensor are placed planarly on the surface of the object to be measured, a force is applied to the temperature sensor, ensuring safe thermal contact between the temperature sensor and the surface. Specifically, the thickness of the circuit board can be between 0.5 mm and 3 mm, while the width of the milled groove and the remaining width of the circuit board tab can be between 0.3 mm and 3 mm, respectively.

[0020] In an advantageous embodiment, the area enclosed by the outer edge of the milled groove is less than 200 square millimeters, preferably less than 100 square millimeters. This allows the use of a temperature sensor with a small housing that essentially occupies the total area of ​​the circuit board platform, wherein possible peripheral components can be arranged on the circuit board very close to the temperature sensor, particularly on the side of the circuit board horizontally away from the temperature sensor.

[0021] To enable contact between the temperature sensor and the analysis and processing unit, printed conductors can extend along the remaining circuit board contacts. Here, the width of the printed conductors can be between 50 mm and 1000 mm, and the conductors can be spaced apart from each other within the range of 50 mm to 1000 mm. In particular, this eliminates the need for external contact of the temperature sensor via metal wires, cables, or the like.

[0022] The temperature sensor can be implemented as a passive component, which is connected to the analysis and processing unit via at least two printed wires. Alternatively, the temperature sensor can be designed as an active component and can be connected to the analysis and processing unit via at least three printed wires.

[0023] In one embodiment of the device, the temperature sensor may be arranged on a first circuit board side, and the analysis processing unit may be arranged on a second circuit board side, such that the analysis processing unit is arranged on the side of the circuit board opposite to the temperature sensor. In particular, the first circuit board side may essentially contain only the temperature sensor, while all other components are arranged on the second side opposite the temperature sensor. This advantageously allows the first circuit board side to lie flush with the surface of the object to be measured, in a manner flush with the spring-supported surface of the temperature sensor. The printed wiring between the temperature sensor and the analysis processing unit may here have plated through-holes penetrating the circuit board.

[0024] In an alternative implementation, the temperature sensor and the analysis processing unit can be arranged on the same side of the circuit board. This allows for a thermal connection between the underside of the temperature sensor and the surface of the object being detected via the circuit board, wherein the circuit board can be optimized for thermal conductivity at the temperature sensor location (Stele).

[0025] The device for current determination includes a shunt and a device for temperature measurement as described above. The shunt has two connection regions and a resistive region electrically located between the connection regions, the resistive region having a substantially flat surface. The device for current determination is arranged on the surface of the shunt in the resistive region such that a temperature sensor is arranged in a manner thermally connected to the resistive region of the shunt. Here, voltage taps are arranged on both sides of the temperature sensor, the voltage taps electrically contacting the surface of the shunt to detect the potential difference along the resistive region.

[0026] In one embodiment of the device, a circuit board is laid flat on a shunt, such that the voltage taps are in electrical contact with the surface of the shunt and a temperature sensor is laid flat on the surface of the shunt. Here, in the installed state of the device, the temperature sensor is displaced relative to the plane of the circuit board by the structural height of the temperature sensor, such that the remaining circuit board tabs apply a reset force to the circuit board platform and thus a clamping force to the temperature sensor. This embodiment satisfies the important requirements of the device for current acquisition in an optimized manner by placing the temperature sensor directly on the resistive region and thermally connecting it to the resistive material in an optimized manner through the spring action of the remaining circuit board tabs, enabling temperature measurement with high accuracy. Additionally, the temperature sensor can be placed at the center of the resistive region and centrally positioned between the voltage taps, so that the temperature is measured precisely in the region where the voltage drop is measured based on the current flowing through the shunt. Thus, in the scope of acquiring the current flowing through the shunt, the temperature-induced changes in the resistance of the material in the resistive region of the shunt can be compensated for in an optimized manner. Meanwhile, the circuit board is laid flat on the surface of the resistive region with minimal distance, so that the printed wires on the circuit board are also only in contact with the surface of the resistive region and largely avoid conductor loops during voltage measurement. The printed wires connect the voltage taps to the measuring circuitry used to determine the voltage drop between the voltage taps.

[0027] In an alternative embodiment of the device, the temperature sensor and analysis processing unit are arranged on the side of the circuit board opposite the shunt. Here, the circuit board platform is mechanically connected to the surface of the shunt, and the circuit board platform is movable relative to the plane of the circuit board. In particular, the side of the circuit board platform opposite the temperature sensor can be connected to the shunt, especially by means of adhesive. Here, possible vertices between the plane of the circuit board and the surface of the shunt, at the location of the circuit board platform, are compensated for by displacing the circuit board platform, and therefore the temperature sensor, relative to its resting position in the plane of the circuit board by such vertices. This embodiment also satisfies the requirements for the device for current acquisition in an optimized manner because the temperature sensor is thermally connected to the resistive material, especially via its underside, through the circuit board platform, and this is maintained even if the position of the circuit board changes relative to the surface of the shunt.

[0028] The thermal connection on the underside of the temperature sensor can be further improved by having a circuit board platform with a thermal conductor, such as a metal pad or multiple copper layers that are at least partially interconnected. By arranging the circuit board on the shunt in a manner as flush as possible, deformation of the shunt and / or the circuit board can occur, particularly through thermal and electromagnetic effects acting on the shunt under high operating currents. This deformation causes the circuit board to lift at least partially off the shunt. This, however, does not affect the thermal connection between the temperature sensor and the shunt, because the circuit board platform is mechanically and securely connected to the shunt and compensates for any misalignment between the plane of the circuit board and the surface of the shunt.

[0029] Specifically, voltage taps can be arranged symmetrically around the temperature sensor and can optionally be implemented as press-in pins, spring contacts, solder connections to the shunt, or threaded connections to the shunt.

[0030] In one embodiment, the shunt can be designed for conducting current with an amplitude greater than 100 amperes, preferably greater than 1000 amperes. Here, the shunt can be constructed from a single material in one piece, wherein the resistive region is formed essentially by a narrowing of the cross-section relative to the connection area of ​​the shunt. This avoids material transitions and reduces manufacturing and installation costs.

[0031] Alternatively, the resistive region of the shunt can be constructed of a different material than the connecting region, for example, a material with different electrical properties, and may optionally include a narrowing of the shunt's cross-section. Here, further improved accuracy in current determination can be achieved by knowing the electrical properties of the material in the resistive region more accurately than the electrical properties of the material in the connecting region, particularly regarding the temperature dependence of the conductivity of the material in the resistive region. It is not necessarily required that the material used in the resistive region of the shunt has a particularly low temperature dependence of conductivity; rather, it is sufficient to understand and / or determine the temperature dependence as accurately and reproducibly as possible.

[0032] In one embodiment, the narrowing of the shunt cross-section in the resistive region may include a value reducing the cross-section to between 10% and 60% of the cross-section of the shunt's connection region. This results in a higher current density in the resistive region than in the shunt's connection region, which in turn causes a higher voltage drop for a given current flowing through the shunt. While this locally increased current density is accompanied by an increased temperature in the resistive region, this effect is neutralized by temperature compensation based on temperature measurements representative of the resistive region and overcompensated by a locally confined and well-defined measurement area.

[0033] To avoid potentially unwanted electrical contact, an electrically insulating film can be placed between the surface of the temperature sensor and the shunt.

[0034] The power converter has current-carrying lines (stromführende Leitungen) for guiding DC and / or AC current processed by the power converter. At least one of the current-carrying lines has a device for current determination as described above, wherein the device bridges an interruption in the current-carrying line or is integrated into the current-carrying line. The power converter is configured to determine the current flowing through the current-carrying lines during operation of the power converter from the potential difference along the resistive region of the shunt, detected by means of a voltage tap, and the resistance value of the resistive region, wherein the resistance value used to calculate the current intensity accordingly is a function of the temperature detected by a temperature sensor.

[0035] In a preferred embodiment, the power converter is designed for rated power greater than 10kW, preferably greater than 100kW, and particularly preferably greater than 1000kW. At these power levels, the determination of the DC and / or AC current processed by the power converter is particularly demanding due to its correspondingly high amplitude, and can be performed with particular accuracy using the described current determination device, which can be readily integrated into the construction of the power converter. Attached Figure Description

[0036] The present invention will now be further illustrated and described with reference to embodiments shown in the accompanying drawings.

[0037] Figure 1 The device used for temperature measurement is shown.

[0038] Figure 2 The apparatus used for current determination is shown.

[0039] Figure 3 A cross-section of one embodiment of a device for current determination is shown, and

[0040] Figure 4 A cross-section of another embodiment of the device for current determination is shown. Detailed Implementation

[0041] Figure 1The illustration shows a temperature measuring assembly 1 as an embodiment of a temperature measuring device according to this application. The temperature measuring assembly 1 includes a circuit board 2. A temperature sensor 3 is arranged on the circuit board 2. A milled groove 4 extends around the temperature sensor 3 in the circuit board 2. The milled groove 4 can be formed in the circuit board 2 before or after mounting the circuit board. The milled groove 4 extends substantially spirally around the temperature sensor 3, leaving a circuit board tab 5, which is bounded on both sides by the milled groove 4 and also extends substantially spirally.

[0042] The spiral shape along which the milled groove 4 extends can be implemented in different ways; in particular, the spiral shape can have substantially straight sections and substantially right-angled directional changes (see...). Figure 1 Alternatively, the spiral shape could be composed of arc segments with different radii. Similarly, non-right-angled directional changes can also be considered. It should be understood that a certain minimum radius cannot be avoided when milling directional changes due to manufacturing technology reasons. Here, directional changes typically involve arcs, and in the case of a 90-degree bend, this can especially be a quarter circle. Therefore, the milled groove 4 can be cost-effectively manufactured in one step, especially using standard tools themselves.

[0043] A circuit board platform 2a is located at the end of the remaining circuit board tab 5, on which a temperature sensor 3 is arranged. The circuit board platform 2a is completely surrounded by a milled groove 4. Additionally, the remaining circuit board tab 5 extends around the circuit board platform 2a in a complete circle. The radius vector of the trajectory of the milled groove 4, i.e., the vector from the center of the circuit board platform 2a to a point in the milled groove 4, extends around the temperature sensor 3 almost twice; that is, this radius vector extends from... Figure 1 The milled groove covers an angle of approximately 700 degrees from its start to its end. In an alternative embodiment, the milled groove 4 may also be shorter and, for example, only encircle the temperature sensor 3 one and a half or one and three-quarters turns, corresponding to an angle of approximately 500 or 600 degrees.

[0044] The temperature measurement assembly 1 also includes an analysis and processing unit 7. The analysis and processing unit 7 can be arranged on the same side of the circuit board 2 or on the opposite side of the temperature sensor 3. The temperature sensor 3 is connected to the analysis and processing unit 7 via printed conductors 6. The printed conductors 6 extend along the remaining circuit board tabs 5.

[0045] The temperature sensor 3 can be implemented as an active or passive component. An active temperature sensor 3 typically requires connection to the analysis and processing unit 7 via at least three lines, while a passive temperature sensor 3 connects to the analysis and processing unit 7 via two to four lines. Accordingly, the printed conductors 6 comprise a suitable number of individual lines extending side-by-side or overlapping each other in the remaining board contacts 5. When using an active component as the temperature sensor 3, the analysis and processing unit 7 can also be located outside the board 2, for example, on another component, allowing the temperature sensor 3 to be connected to suitable programmable logic or a microcontroller via the printed conductors 5 and additional cabling.

[0046] Figure 2 A device for current acquisition is shown, comprising a current acquisition component 10 and a shunt 11. In this example, the shunt 11 is constructed as a single piece and includes a connection region 11a and a resistive region 11b. The connection region 11a is designed here for connection to a bus, which is, for example, part of a power converter and delivers high DC or AC current. For this purpose, the shunt 11 can bridge an interruption of the bus or can form a bus itself, for example, by connecting the input port of the power converter or a semi-printed wire to one end of the shunt 11 and / or by connecting an induction coil to another end of the shunt 11. Alternatively, a relay. Alternatively or additionally, the connection region 11a may be configured for connection to other types of current-carrying lines, such as cables, and may have connection elements 14 for electrical and / or mechanical connection to adjacent components. In principle, the resistive region 11b may also be integrated into the current-carrying line such that the connection region 11a represents only the electrical contact structure between the resistive region 11b and adjacent components.

[0047] The current obtaining component 10 has a current obtaining component based on Figure 1 A device for temperature measurement, comprising a circuit board 2, a temperature sensor 3, and a milled groove 4 extending around the temperature sensor 3. The temperature sensor 3 may be arranged on the side of the circuit board 2 facing the shunt 11, i.e., between the surface of the circuit board 2 and the surface of the resistor region 11b, see [reference needed]. Figure 3 Temperature sensor 3 can also be arranged on the side of circuit board 2 opposite to shunt 11, that is, on the same side as analysis and processing unit 7, see [reference]. Figure 4Additionally, the current acquisition assembly 10 has two voltage taps 12 arranged in front of and behind the temperature sensor 3 along the flow direction of the current I, and conductively connected to the surface of the resistive region 11b. The voltage taps 12 are connected to a voltage measuring device 13, which detects the voltage difference between the potentials on the surface of the resistive region 11b at the locations of the voltage taps 12.

[0048] The analysis and processing unit, not shown here, can be implemented in conjunction with or independently of the analysis and processing unit 7. It can determine the magnitude of the current I flowing through the shunt 11 based on the measured value of the voltage measuring device 13 and the resistance of the resistance region 11b according to Ohm's law. The resistance of the resistance region 11b is typically temperature-dependent. Therefore, the resistance used in the calculation when determining the current intensity is predetermined based on the temperature of the resistance region 11b obtained by the temperature sensor 3.

[0049] The cross-section of the resistive region 11b is smaller than that of the connecting region 11a. Therefore, the current density of the current I flowing through the shunt 11 increases in the resistive region 11b. Since the shunt 11 itself is optimized for minimal losses, this increase in current density is advantageous to create a voltage difference between the voltage taps 12 that is sufficiently high to be safely within the measurement range of the voltage measuring device 13. (Alternative to or additional to according to...) Figure 2 In the narrowed section of the cross-section, the material composition of the resistive region 11b may be different from that of the connecting region 11a, for example, a material with (slightly) increased resistance and / or a temperature-dependent material with decreased resistance.

[0050] Figure 3 Showing according to Figure 2 The device for current determination has a cross-section at the height of the resistive region 11b. The circuit board 2 is placed flush with the surface of the shunt 11. The temperature sensor 3 is arranged on the side of the circuit board 2 facing the shunt 11, i.e., between the surface of the circuit board 2 and the resistive region 11b, and is also placed flush with the surface of the resistive region 11. Thus, the temperature sensor 3 has been displaced relative to the plane of the circuit board 2 by its structural height 8a compared to its static position in the unmounted state, in such a way that the normal vector of the circuit board platform 2a parallel to the plane of the circuit board 2 is offset by the structural height 8a. This is possible because the circuit board platform 2a is connected to the rest of the circuit board 2 only through the remaining circuit board tab 5. Therefore, the offset of the circuit board platform 2a by the structural height 8a is distributed across the elastic deformation of the entire circuit board tab 5, which has a moderate slope relative to the plane of the circuit board 2.

[0051] The elastic deformation of the circuit board contact 5 generates a restoring force that presses the temperature sensor 3 against the surface of the resistive region 11b. Simultaneously, the voltage tap 12 is pressed against the surface of the resistive region 11b by the circuit board 2 itself, and thus makes electrical contact with it. Alternatively or additionally, the voltage tap 12 also establishes a mechanical connection between the circuit board 2 and the shunt 11, for example, by configuring the voltage tap 11 as a press-in contact that is pressed into corresponding drilled holes in the surfaces of the circuit board 2 and the shunt 11. Other electrical and / or mechanical contact structures between the voltage tap 12 and the resistive region 11b are also conceivable, such as by spring pins, threaded connections, welded connections, or the like.

[0052] The offset of the circuit board platform 2a, achieved by milling groove 4, allows the circuit board 2 to be arranged flush with the surface of the resistive region 11b, even though the temperature sensor 3 is arranged between the surface of the circuit board 2 and the shunt 11. Thus, the electrical connections required for measuring the voltage drop between the voltage taps 12, especially the lines between the voltage taps 12 and the voltage measuring device 13, can extend close to the surface of the resistive region 11b, and the conductor loops that are disadvantageous in this respect, especially those oriented perpendicularly to the surface of the shunt 11, can be minimized to a large extent.

[0053] Figure 4 Showing according to Figure 2 Another embodiment of the device for current determination shows a cross-section at the height of the resistive region 11b. The temperature sensor 3 is arranged on the side of the circuit board 2 opposite to the shunt 11, i.e., on the same side as the analysis and processing unit 7. The circuit board platform 2a, on which the temperature sensor 3 is arranged, rests flat on the surface of the resistive region 11b and is mechanically connected to the shunt 11, for example, by means of an adhesive 9a, which can be a thermally conductive adhesive and can be optimized for high thermal conductivity. A thermal conductor 9b, such as a copper inlay or multiple copper layers at least partially interconnected, can be arranged in the circuit board platform 2a, thereby improving the thermal connection between the underside of the temperature sensor 3 and the side of the circuit board platform 2a facing the shunt 11.

[0054] The circuit board 2 may have a certain offset 8b from the surface of the shunt 11. This offset may be intentional, for example, for structural reasons. During manufacturing, the offset between the plane of the circuit board 2 and the surface of the shunt 11 can also be minimized, in particular by placing the circuit board flat on the shunt 11; however, after installation, additional offset may occur, particularly at the location of the circuit board platform 2a, for example if the shunt 11 and / or the circuit board 2 are to deform. Undesirable deformation of the shunt 11 itself may occur, for example, due to mechanical forces during installation or transport, and due to thermal expansion and / or electromagnetic forces during operation, especially when the shunt 11 is mechanically fixed in the connection area 11a by means of the connecting element 14.

[0055] Through the mechanical connection between the circuit board platform 2a and the shunt 11, the temperature sensor 3 is displaced parallel to the normal vector of the plane of the circuit board 2, more precisely, by the same amount as the correct offset between the surfaces of the circuit board 2 and the shunt 11 at its location on the circuit board platform 2a. This is possible because the circuit board platform 2a is connected to the rest of the circuit board 2 only via the remaining circuit board tab 5. The offset of the circuit board 2 relative to the surface of the shunt 11 is thus distributed across the elastic deformation of the entire circuit board tab 5, which has a moderate slope relative to the plane of the circuit board 2. Here, this offset generates a restoring force between the fixed circuit board level 2a and the circuit board 2, such that the circuit board 2 is also pulled by the circuit board tab 5 in addition to the shunt 11. Additionally, the circuit board tab 5 allows for compensation for possible lateral offsets of the circuit board 2 relative to its normal mounting position.

[0056] In this configuration, voltage tap 12 is electrically and mechanically connected to resistive region 11b, for example, by press-fit contact, spring pin, threaded connection, plug connection, or welded connection or the like.

[0057] Therefore, the offset of the circuit board 2 is achieved by milling the groove 4 while simultaneously ensuring thermal connection between the temperature sensor 3 and the resistive region 11b. This allows for tolerance of some deformation of the shunt 11 during operation. Alternatively or additionally, the requirements for the shape stability of the shunt 11 can be reduced depending on thermal and / or mechanical edge conditions, for example, by making the shunt 11 thinner overall and correspondingly more cost-effective.

[0058] According to Figure 4In this embodiment, the lower side of the temperature sensor 3 is thermally connected to the resistive region 11b of the shunt 11 via the circuit board platform 2a. Here, the temperature sensor 3 can be decoupled from the surrounding air by means of a cover, so that the upper side of the temperature sensor 3 is not affected by possible airflow above the circuit board 2, but is largely in thermal equilibrium only with the resistive region. This further improves the measurement of the temperature of the resistive region.

[0059] List of reference numerals

[0060] 1 Temperature Measurement Component

[0061] 2 Circuit Boards

[0062] 2a Circuit Board Platform

[0063] 3 Temperature sensor

[0064] 4. Milling grooves

[0065] 5. Circuit board connector

[0066] 6. Printed wires

[0067] 7. Analysis and Processing Unit

[0068] 8a Structural height

[0069] 8b offset

[0070] 9a Adhesive

[0071] 9b Thermal conductor

[0072] 10 Current Calculation Component

[0073] 11 shunt

[0074] 11a Connection Area

[0075] 11b Resistor Region

[0076] 12 voltage taps

[0077] 13 Voltage measuring instrument

[0078] 14 Connecting elements

Claims

1. A device for current determination, the device comprising a shunt (11) and a circuit board (2), an analysis and processing unit (7) and a temperature sensor (3), wherein, The shunt has a resistive region (11b) having a substantially flat surface, wherein the device for current determination is arranged on the surface of the shunt (11) in the resistive region (11b) such that the temperature sensor (3) is arranged thermally connected to the resistive region (11b) of the shunt (11), wherein voltage taps (12) are arranged on both sides of the temperature sensor (3) and electrically contact the surface of the shunt (11) to detect the potential difference along the resistive region (11b), wherein the circuit board (2) has milled The groove (4) extends substantially spirally around the temperature sensor (3), such that the temperature sensor (3) is arranged on the circuit board platform (2a) and is spring-supported by the circuit board tabs (5) remaining between the coils of the spiral groove (4), wherein the temperature sensor (3) is capable of shifting parallel to the normal vector of the plane of the circuit board (2), and in the event of the shift of the temperature sensor (3) relative to the plane of the circuit board (2), a restoring force is generated between the circuit board (2) and the temperature sensor (3) by means of the circuit board tabs (5).

2. The device according to claim 1, wherein, The circuit board (2) is laid flat on the shunt (11) such that the voltage tap (12) is in electrical contact with the surface of the shunt (11), and the temperature sensor (3) is laid flat on the surface of the shunt (11), wherein the temperature sensor (3) is displaced relative to the plane of the circuit board (2) by the structural height (8a) of the temperature sensor, such that the remaining circuit board tab (5) applies a reset force to the circuit board platform (2a) and thus applies a clamping force to the temperature sensor (3).

3. The device according to claim 1, wherein, The temperature sensor (3) and the analysis and processing unit (7) are arranged on the side of the circuit board (2) opposite to the shunt (11), wherein the circuit board platform (2a) is mechanically connected to the surface of the shunt (11), wherein the circuit board platform (2a) is capable of displacement relative to the plane of the circuit board (2) and compensating for the offset between the plane of the circuit board (2) and the surface of the shunt (11) at the location of the circuit board platform (2a).

4. The device according to claim 3, wherein, The circuit board platform (2a) has a thermal conductor (9b) for establishing a thermal connection between the temperature sensor (3) and the resistive region (11b).

5. The device according to any one of claims 1 to 4, wherein, The printed conductor (6) extends along the remaining circuit board tab (5) to make the temperature sensor (3) contact the analysis and processing unit (7).

6. The device according to any one of claims 1 to 4, wherein, The voltage tap (12) is implemented as a press-in pin in the circuit board (2), a spring contact, a welded connection to the shunt (11), or a threaded connection to the shunt (11).

7. The device according to any one of claims 1 to 4, wherein, The shunt (11) is designed for conducting currents with an amplitude greater than 100 amperes.

8. The device according to claim 7, wherein, The amplitude of the current is greater than 1000 amperes.

9. The device according to any one of claims 1 to 4, wherein, The shunt (11) has two connection regions (11a), wherein the resistive region (11b) is arranged between the connection regions (11a) and is formed substantially by a narrowing of the cross-section of the connection region (11a) of the shunt (11).

10. The device according to any one of claims 1 to 4, wherein, The shunt (11) has two connection regions (11a), wherein the resistive region (11b) is arranged between the connection regions (11a), and the resistive region is made of a material different from that of the connection regions (11a), and the resistive region optionally includes a narrowing of the cross-section of the shunt (11).

11. The device according to claim 9, wherein, The narrowing includes reducing the cross-section to a value between 10% and 60% of the cross-section of the connection region (11a) of the splitter (11).

12. The device according to claim 10, wherein, The narrowing includes reducing the cross-section to a value between 10% and 60% of the cross-section of the connection region (11a) of the splitter (11).

13. The device according to claim 2, wherein, An electrically insulating film is arranged between the surface of the temperature sensor (3) and the shunt (11).

14. The device according to claim 3 or 4, wherein, The circuit board platform (2a) is mechanically connected to the surface of the shunt (11) by means of an adhesive (9a).

15. A power converter having current-carrying lines for guiding direct current and / or alternating current processed by the power converter, wherein, At least one of the current-carrying lines has a device for current determination according to any one of claims 1 to 14, the device for current determination bridging an interruption of the current-carrying line or being integrated into the current-carrying line, wherein the power converter is configured to determine the current flowing through the current-carrying line during operation of the power converter by means of the potential difference along the resistive region (11b) of the shunt (11) detected by means of the voltage tap (12) and the resistance value of the resistive region (11b), wherein the resistance value is a function of the temperature detected by the temperature sensor (3).

16. The power converter according to claim 15, wherein, The power converter is designed for the following rated power: the rated power is greater than 10kW.

17. The power converter according to claim 16, wherein, The rated power is greater than 100kW.

18. The power converter according to claim 17, wherein, The rated power is greater than 1000kW.

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