Device, method and vehicle for determining an electric current flowing through a conductor in a vehicle

Abstract

The invention relates to a device (2) for determining an electric current flowing through a conductor (3) in a vehicle (1). The device (2) has a magnetic core (4) which is designed to enclose the conductor (3) in a ring shape. The magnetic core (4) is at least partially interrupted along the ring-shaped course (7) by a first air gap (8). The device (2) has a magnetic field sensor (5) which is located within the first air gap (8) and is designed to generate a sensor signal (5a) from a magnetic flux caused by the electric current in the first air gap (8). The magnetic core (4) is at least partially interrupted along the ring-shaped course (7) by a second air gap (9). The gap width of the first air gap (8) is smaller than the gap width of the second air gap (9). The device (2) has an evaluation unit (6) in order to determine an actual value of the electric current from the sensor signal (5a). The invention also relates to a vehicle (1) and a method for determining an electric current flowing through a conductor (3) in a vehicle (1).

Description

Technical Field

[0001] This invention relates to an apparatus for determining the current flowing through a wire in a vehicle. Other aspects of the invention relate to a vehicle having such an apparatus and a method for determining the current flowing through a wire in the vehicle using such an apparatus. Background Technology

[0002] Devices for determining the current flowing through a conductor are known in the prior art. A variation of this could be a non-contact measuring device that uses a magnetic core to determine the current. Such devices are also known, in particular, for use in vehicles.

[0003] In some embodiments, the magnetic core is here looped around the conductor. For example, see document DE102021111412A1, which proposes a current measuring system for measuring, particularly indirectly, the current flowing through an electrical conductor. This current measuring system has a magnetic core with a through-hole and a maximum cross-sectional area. Here, the magnetic core is broken at one point to form an air gap. Two cross-sectional areas of the magnetic core are exposed there to define the air gap. At least one sensor is mounted on the magnetic core and precisely positioned within the air gap, more specifically, to measure the magnetic flux appearing in the magnetic core when the electrical conductor passes through the through-hole and a current flows through the conductor.

[0004] A current measuring device is known from WO2010 / 106304A, which has a first arm and a second arm made of a magnetically conductive material, arranged such that the first and second arms surround a cable that guides a current to be measured or detected. Here, the first and second arms converge at a connection point, wherein each arm and the connection point form a magnetic circuit around the cable. A magnetic sensor, such as a Hall effect sensor, is provided at at least one connection point for detecting or measuring the current. A sleeve made of the magnetically conductive material is arranged and positioned such that, when the arms are placed around the cable, the sleeve substantially surrounds the connection point housing the sensor to shield the first magnetic field sensor from stray magnetic fields. A gap may exist between the two arms at the connection point to prevent the magnetic field generated by the current to be measured from being conducted away from the sensor through the arms, and the sleeve may have an opening pointing towards the cable to prevent the sensor from being shielded relative to the magnetic field generated by the current.

[0005] Ideally, the current should be determined as accurately or reliably as possible. However, this can be reversed when the current is very high, as the core operates in its magnetic saturation region and therefore in a nonlinear region. Summary of the Invention

[0006] The objective of this invention is to determine the current flowing through a conductor with high accuracy and / or high reliability, especially without contact.

[0007] According to the present invention, this task is accomplished by the technical solutions of the independent claims. Advantageous embodiments of the present invention are the technical solutions of the dependent claims and the specification.

[0008] According to one aspect of the invention, an apparatus is provided for determining the current flowing through a conductor, particularly an electrical conductor, in a vehicle. The apparatus includes a magnetic core designed to loop around the conductor in a circular or substantially circular manner. The magnetic core is at least partially interrupted along its circular orientation by a first air gap. The apparatus includes a magnetic field sensor located within the first air gap and configured to generate a sensor signal based on the magnetic flux (also called magnetic flux) induced by the current in the first air gap. The magnetic core is at least partially interrupted along its circular orientation by a second air gap. The width of the first air gap is smaller than the width of the second air gap. The apparatus includes an evaluation unit configured to determine the actual value of the current flowing through the conductor based on the sensor signal.

[0009] The conductors herein can be, in particular, conductors used to provide electrical power to a vehicle's fully electric drive system or hybrid drive system. The conductors can be, in particular, buses having, for example, a rectangular cross-section. The conductors are particularly designed to be single-core, i.e., having exactly one core wire or strand, so that the possible return conductor is therefore located, for example, outside the loop. It is also possible that the conductor comprises multiple core wires, wherein the respective currents flowing through said multiple core wires are, in particular, in the same direction.

[0010] Magnetic cores, in particular, contain materials with high permeability, especially much higher than that of air. For example, magnetic cores may contain or be made of ferromagnetic materials.

[0011] The toroidal orientation can be circular and / or substantially circular and / or rectangular and / or substantially rectangular and / or elliptical and / or substantially elliptical. In other words, the core can be designed such that the toroidal orientation extends around the conductor in a loop or as a ring. In particular, the shape of the toroidal orientation can follow the cross-sectional geometry of the conductor, for example, it can be adapted to the cross-sectional geometry of the conductor. In particular, the core can be designed with the conductor located at its center by means of the toroidal orientation. For example, the inner diameter of the toroidal orientation or the core is larger than the outer diameter of the conductor's maximum cross-section. Therefore, the core can be designed in particular to allow the conductor to be guided through the toroidal orientation without contact. In other words, the core has a through opening by means of the toroidal orientation through which the conductor extends.

[0012] In at least one embodiment, the device may in particular have the wire.

[0013] In other words, the first air gap can also be referred to as a gap that interrupts the toroidal orientation of the magnetic core using a material with low magnetic permeability. The first air gap can, for example, mean the absence of ferromagnetic material and can, but is not necessarily, formed of air. The material with low magnetic permeability can, for example, be air and / or plastics and / or ceramics. In particular, the first air gap can also be a vacuum. In particular, the material with low magnetic permeability has low electrical conductivity. Similarly, the second air gap can partially or completely possess the characteristics of the first air gap.

[0014] In other words, the interruption of the magnetic core by the first and / or second air gap can be understood as a change in permeability along the annular direction due to changes in material properties. Specifically, the magnetic core may have a first boundary surface at the first air gap, where the permeability changes abruptly from a high value to a low value within the first air gap. Similarly, the magnetic core may have a second boundary surface at the first air gap, exhibiting the opposite change.

[0015] In particular, here and below, the term "gap width" can also be referred to as the length of the gap. Therefore, the gap width of the first air gap can be referred to as the length of the first air gap and the gap width of the second air gap can be referred to as the length of the second air gap.

[0016] Magnetic reluctance characterizes the saturation properties of a magnetic core; in other words, it characterizes the saturation magnetization of the core. The saturation properties of a core can, in particular, depend on the cross-sectional area of ​​the core and / or the material of the core and / or the gap width of the first air gap and / or the gap width of the second air gap. Specifically, the first air gap and / or the second air gap can result in a higher magnetic reluctance value compared to cores with the same external geometry and no air gap or only one of two air gaps. In particular, the saturation properties related to the magnetic field induced by the current flowing through the conductor are observed here and below.

[0017] A high current flowing through a conductor can result in a high magnetic field, i.e., a high magnetic flux density. In a saturated core, a linear increase in current can, for example, lead to a nonlinear increase in magnetic flux density. In particular, in an unsaturated core, a linear increase in current can, for example, lead to a linear increase in magnetic flux density. It is especially advantageous, in terms of resolution accuracy, to use the region where the magnetic flux density increases linearly with the aid of an unsaturated core to determine the current flowing through the conductor.

[0018] In particular, the second air gap is not adjacent to the first air gap. For example, the second air gap is located on a circumferential orientation opposite to the first air gap.

[0019] In particular, the width of the first air gap is at least twice, at least five times, or at least ten times smaller than the width of the second air gap. The second air gap may also be referred to as a saturation gap based on its larger width compared to the first air gap.

[0020] In other words, a magnetic field sensor can also be called a magnetometer. A magnetic field sensor can include sensing devices for determining the magnetic field and / or magnetic flux and / or magnetic flux density. In particular, the magnetic field sensor can provide a sensor signal, which corresponds, for example, to a voltage. The amplitude of this voltage may, for example, depend on the magnetic flux density or magnetic flux value of the magnetic field at the location of the magnetic field sensor. In particular, the magnetic field sensor can be located at a fixed position within a first air gap.

[0021] In particular, the evaluation unit can be configured to evaluate the determined current and / or provide the determined current to other vehicle systems, such as the electronic control unit (ECU). Specifically, the evaluation unit itself can also be part of the ECU. The evaluation unit can have a data processing system.

[0022] A data processing system can be characterized, for example, as a device having processing circuitry for processing data. A data processing system can, for example, perform computational operations, and in particular, includes database access for reading and / or storing data.

[0023] The data processing system may, for example, have a computer and / or a microcontroller and / or one or more integrated circuits. Here, the data processing system may have at least one processor and / or at least one semiconductor chip. Furthermore, the data processing system may have at least one hardware interface and / or software interface, which may be configured, for example, to receive and / or provide data.

[0024] Data processing systems may also have storage units for storing data, such as volatile data memory and / or non-volatile data memory and / or permanent data memory. In particular, data processing systems may have semiconductor memory.

[0025] The advantage of this invention is that the gap widths of the first air gap and the second air gap can be designed independently of each other. Therefore, the gap width of the first air gap can be optimized for measurements using a magnetic field sensor. Furthermore, a very small gap width can be chosen for this purpose, as the resulting high field density and field uniformity of the magnetic field are beneficial for determining the magnetic flux. In particular, a small air gap is advantageous for determining the magnetic flux with high accuracy. The magnetic field can be uniform, and especially uniform with respect to the geometry of the magnetic field sensor. Specifically, the standard deviation of the absolute values ​​of the magnetic field and / or magnetic flux within the first air gap can be 50 to 100 times smaller than the standard deviation of the absolute values ​​of the magnetic field and / or magnetic flux within the second air gap. That is, the magnetic field sensor in the first air gap can therefore be significantly less sensitive to slight positional changes and / or vibrations compared to an alternative magnetic field sensor arranged in the second air gap.

[0026] Furthermore, the width of the second air gap can be optimized to meet the requirements of the magnetic core's saturation characteristics. In particular, the width of the second air gap can be larger than, and significantly larger than, the width of the first air gap to accommodate measurements with high current intensities. The second air gap can function as a saturation gap and correspondingly enable the device to operate under conditions of high or extremely high current intensities.

[0027] In particular, the requirements for the optimal gap width due to sensor placement and adaptation to the saturation region can be contradictory, thus necessitating a compromise, especially in devices with only one air gap, that may compromise the achievement of both optimization objectives. Specifically, in the device according to the invention, the saturation characteristics of the magnetic core can be adapted solely by changing the gap width of the second air gap, independent of the potential reduction in the high-precision determination of magnetic flux using a magnetic field sensor.

[0028] According to at least one embodiment, the magnetic core is at least partially interrupted along its annular orientation by a third air gap. The device includes an additional magnetic field sensor located within the third air gap and configured to generate an additional sensor signal based on additional magnetic flux induced by current within the third air gap. Furthermore, the gap width of the third air gap is smaller than the gap width of the second air gap. Additionally, an evaluation unit is configured to determine an additional actual value for the current flowing through the conductor based on the additional sensor signal.

[0029] In particular, the width of the third air gap may be the same as or different from the width of the first air gap. In other words, the additional magnetic field sensor may also be referred to as an additional magnetometer. The additional magnetic field sensor may include sensing devices for determining the magnetic field and / or magnetic flux and / or magnetic flux density within the third air gap. In particular, the additional magnetic field sensor may have the same or some of the features of the aforementioned magnetic field sensor.

[0030] By appropriately selecting the gap width of the first air gap in combination with the gap width of the third air gap, it is possible to cover different measurement ranges of the current using the device. Accordingly, for example, the magnetic field sensor can cover a first measurement range of the current with high accuracy, and the additional magnetic field sensor can cover a second measurement range of the current with high accuracy. Here, the first and second measurement ranges can overlap.

[0031] In particular, the third air gap is not adjacent to the first or second air gap. For example, the third air gap is located on a circumferential orientation opposite to the first air gap and spaced apart from the second air gap.

[0032] In other words, the third air gap can also be called an additional gap, which utilizes a material with low magnetic permeability to interrupt the toroidal orientation of the magnetic core. The third air gap can, for example, represent the absence of ferromagnetic material. The material with low magnetic permeability can be, for example, air and / or plastics and / or ceramics. In particular, the material with low magnetic permeability has low electrical conductivity. In particular, the third air gap can also be a vacuum.

[0033] The additional actual value may be nominally the same as or nearly the same as the actual value. For example, the current may be determined by the additional magnetic field sensor for redundancy reasons.

[0034] The evaluation unit may, in particular, be configured to compare the sensor signal with the additional sensor signal. For example, the evaluation unit may be configured to determine and provide an average of the actual value and the additional actual value. In particular, the evaluation unit may also provide only the actual value and / or the additional actual value. Similarly, the apparatus may also include an additional evaluation unit to determine the additional sensor signal.

[0035] The advantage of these implementations is that the device is fail-safe due to the failure or malfunction of the additional magnetic field sensor relative to one of the magnetic field sensors. Similarly, the accuracy of current determination can be improved based on the determination by the additional magnetic field sensor, for example, by appropriately selecting the gap width for the measurement range. In particular, the gap width of the third air gap can be smaller than the gap width of the second air gap, and correspondingly, the third air gap can have a uniform magnetic field. The saturation characteristics of the magnetic core can remain substantially unchanged compared to the saturation characteristics of a magnetic core without a third air gap, based on the third air gap, and can be adapted by means of the gap width of the second air gap.

[0036] According to at least one other embodiment, the device has a casting material, particularly a casting material made of a non-magnetic material.

[0037] According to at least one other embodiment, the magnetic field sensor is surrounded, in particular completely surrounded, by a casting material.

[0038] According to at least one other embodiment, the magnetic core is at least partially surrounded by a casting material.

[0039] The casting material here may, for example, be bitumen and / or resin and / or wax and / or plastic. Similarly, the wires may, for example, be encased in the casting material. Likewise, the additional magnetic field sensor may, for example, be encased in the casting material.

[0040] The casting material can protect the device from environmental influences, such as moisture and / or gases and / or solids and / or vibrations. Similarly, the casting material can mechanically stabilize the device, especially when the magnetic core is interrupted by a first air gap and / or a second air gap and / or a third air gap. The casting material can, in particular, be a material with low magnetic permeability.

[0041] The advantage of these implementations is that the casting material ensures protection of the device, especially protection from environmental influences. Furthermore, the casting material improves the mechanical stability of the device.

[0042] According to at least one other embodiment, the second air gap is completely filled with a non-magnetic material.

[0043] Non-magnetic materials here have low magnetic permeability, for example, due to the absence of ferromagnetic materials. In particular, non-magnetic materials can be air, plastics, ceramics, or casting materials.

[0044] For example, the first air gap and / or the third air gap can be completely filled with a non-magnetic material.

[0045] According to at least one embodiment, the device has a ferromagnetic tab that bridges, in particular, the second air gap along a circumferential direction.

[0046] The ferromagnetic tab can, in particular, contain the same material as or be made of the same material as the magnetic core. Specifically, except for the region containing the ferromagnetic tab, the second air gap is filled with a non-magnetic material along an annular direction. In other words, the ferromagnetic tab can be referred to as the connection between the first part and the second part of the magnetic core. In other words, the ferromagnetic tab can be referred to as a magnetic short circuit in the second air gap.

[0047] The advantage of these implementations is that the mechanical stability of the magnetic core can be improved based on the ferromagnetic tabs. Similarly, the saturation characteristics of the magnetic core can be affected, for example, by the width of the ferromagnetic tabs.

[0048] According to another embodiment, the cross-sectional area of ​​the ferromagnetic contact is less than 20% or 5% of the cross-sectional area of ​​the magnetic core at the second air gap.

[0049] In other words, the ferromagnetic connector only partially bridges the second air gap. In particular, the second air gap is mostly made of non-magnetic material.

[0050] The ratio of the cross-sectional area of ​​the ferromagnetic contact to that of the magnetic core can be designed, for example, such that the ferromagnetic contact saturates at low current intensities and therefore has only a small or no effect on the saturation characteristics of the magnetic core at higher and / or very high current intensities. For this reason, the cross-sectional area of ​​the ferromagnetic contact can be made as small as possible, for example.

[0051] The introduction of ferromagnetic tabs can, in particular, only slightly affect the saturation characteristics of the core at higher and / or higher current intensities. Furthermore, due to their small cross-sectional area, the ferromagnetic tabs can have a small effect on the enhancement characteristics of the core at higher and / or higher current intensities, i.e., with saturated ferromagnetic tabs. Here, the enhancement characteristics involve an increase in the detectable magnetic field in the first air gap of the core, related to the current flowing through the conductor surrounding the core.

[0052] The advantage of these implementations is that the core can be designed to saturate in the direction of high current intensity, because the small cross-sectional area of ​​the ferromagnetic tabs means that, for example, at high current intensity, the ferromagnetic tabs may have only a slight effect on the saturation characteristics and / or enhancement characteristics.

[0053] According to at least one other embodiment, the device has an additional ferromagnetic tab that bridges the second air gap along an annular path.

[0054] In particular, the features of the aforementioned ferromagnetic contacts can be applied partially or completely to the other ferromagnetic contacts.

[0055] The advantage of these implementations is that the additional ferromagnetic tabs can further improve mechanical stability.

[0056] According to at least one other embodiment, the magnetic core has a lamination group and / or the magnetic core is implemented as a lamination group and / or the magnetic core is implemented as a lamination.

[0057] The lamination assembly may, in particular, contain materials with high magnetic permeability, such as iron and / or iron alloys and / or steel and / or steel alloys. In particular, the lamination assembly may contain ferromagnetic materials.

[0058] In particular, the lamination assembly may have at least one layer in the form of at least one electrical steel sheet, which is cut and / or stamped into a predetermined geometry. For example, the lamination assembly may be constructed in multiple layers and accordingly include a plurality of such electrical steel sheets, especially stacked on top of each other. In particular, the lamination assembly may be made based on at least one layer of electrical steel sheet by means of a stamping process and / or by means of an adhesive process.

[0059] The advantage of these implementations is that the magnetic core can be manufactured quickly and / or repeatedly and / or at low cost as a stack.

[0060] According to at least one embodiment, the lamination group has the ferromagnetic tab and / or the additional ferromagnetic tab.

[0061] In other words, the ferromagnetic tab and / or the additional ferromagnetic tab are part of a stack.

[0062] In particular, at least one layer of electrical steel sheet can also form the ferromagnetic tab and / or the additional ferromagnetic tab. In particular, the stacked assembly can be designed as a single piece and has the magnetic core and the ferromagnetic tab and / or the additional ferromagnetic tab.

[0063] The advantage of this implementation is that the stacked assembly can be manufactured at low cost and repeatedly by means of a stamping process or by means of a bonding process, and the ferromagnetic tabs and / or the additional ferromagnetic tabs can be produced, for example, in the same process.

[0064] According to at least one other embodiment, the magnetic field sensor has a Hall sensor or a Hall sensor.

[0065] A Hall sensor may have a surface and be configured to provide an output voltage whose value depends on a magnetic field extending perpendicularly to the surface of the Hall sensor. A Hall sensor can, for example, detect magnetic flux using the Hall effect.

[0066] The advantages of these implementations are that the Hall sensor can be placed in the first air gap and the accuracy of current determination can be further improved based on its structural type and measurement principle. Furthermore, cost advantages can also be achieved by using a Hall sensor.

[0067] According to another aspect of the invention, a vehicle is provided having a conductor and a device according to any one of the preceding claims, wherein the magnetic core of the device is annularly wrapped around the conductor.

[0068] According to at least one embodiment, the vehicle has a fully electric drive system or a hybrid drive system with electrical subsystems, wherein the device is a component of the electric drive system or the hybrid drive system.

[0069] Another aspect of the invention relates to a method for determining the current flowing through a conductor in a vehicle using a device according to the invention. In this method, a magnetic core of the device is annularly wound around the conductor. Furthermore, a sensor signal is generated based on the magnetic flux induced by the current in a first air gap. Additionally, the actual value of the current flowing through the conductor is determined based on the sensor signal.

[0070] Other features of the invention are derived from the claims, drawings, and description of the drawings. The features and combinations thereof mentioned above in the specification, as well as those mentioned below in the description of the drawings and / or shown separately in the drawings, can be used not only in the combinations given separately, but also in other combinations or individually. Attached Figure Description

[0071] The embodiments of the present invention will now be described in more detail with the aid of schematic drawings. Wherein:

[0072] Figure 1A schematic diagram of a motor vehicle is shown, which is an embodiment of a vehicle according to one aspect of the present invention and has an embodiment of a device according to the present invention for determining the current flowing through a wire in the vehicle; and

[0073] Figure 2 A schematic diagram illustrating one embodiment of the device according to the invention; and

[0074] Figure 3 A perspective view showing one embodiment of the device according to the invention; and

[0075] Figure 4 A schematic diagram illustrating another embodiment of the device according to the invention; and

[0076] Figure 5 A perspective view showing another embodiment of the device according to the invention; and

[0077] Figure 6 A schematic diagram illustrating another embodiment of the device according to the invention; and

[0078] Figure 7 A perspective view showing another embodiment of the device according to the invention; and

[0079] Figure 8 A schematic diagram illustrating another embodiment of the device according to the invention; and

[0080] Figure 9 A schematic diagram illustrating another embodiment of the device according to the invention; and

[0081] Figure 10 A perspective view showing another embodiment of the device according to the invention; and

[0082] Figure 11 A graph showing simulation data for at least one embodiment of the device according to the invention; and

[0083] Figure 12 A graph showing simulation data for at least one embodiment of the device according to the invention; and

[0084] Figure 13 A graph showing simulation data for at least one embodiment of the device according to the invention; and

[0085] Figure 14 A graph showing simulation data for at least one embodiment of the device according to the invention. Detailed Implementation

[0086] exist Figure 1The diagram shows vehicle 1. Vehicle 1 is a motor vehicle. For example, a vehicle could be a car, a truck, or a bus.

[0087] Vehicle 1 has a device 2 according to the invention for determining the current flowing through conductor 3. The device has at least one magnetic core 4, a magnetic field sensor 5, and an evaluation unit 6.

[0088] The conductor 3 can be designed, for example, to provide electrical power to the drive system of the vehicle 1. In particular, the drive system can drive the vehicle 1 either fully electrically or in a hybrid manner (i.e., partially electrically).

[0089] In at least one embodiment of device 2, the magnetic core 4 is in Figure 2 The figure is shown in a schematic cross-sectional view. Here, the magnetic core 4 is annularly wrapped around the wire 3. In other words, the wire 3 extends orthogonally to the plane of the figure through a through opening in the magnetic core 4. The wire 3 is shown as a bus in the figure. In one embodiment, the device 2 may include the wire 3.

[0090] The magnetic core 4 is at least partially interrupted along the annular direction 7 by the first air gap 8, and in the illustrated embodiment, completely interrupted. In other words, the first air gap 8 specifically represents the complete interruption of the magnetic core 4 along the annular direction 7, particularly by a material having low permeability (especially a permeability value in the range of 1). This material can be, for example, air and / or plastic and / or ceramic and / or casting material. The first air gap 8 may extend uniformly toward the direction of the wire 3.

[0091] A magnetic field sensor 5 is located within the first air gap 8 and is configured to generate a sensor signal 5a based on the magnetic flux induced by the current in the first air gap 8. The sensor signal 5a can be provided, in particular, to the evaluation unit 6. The sensor signal 5a can be, for example, a voltage whose amplitude depends on the value of the magnetic flux in the first air gap 8.

[0092] The magnetic field sensor 5 is specifically located at or near the center of the first air gap 8. For example, the magnetic field sensor 5 may be cast or injection molded within the first air gap 8 and / or the magnetic core 4.

[0093] Furthermore, the magnetic core 4 is at least partially interrupted along the annular direction 7 by the second air gap 9, or completely interrupted in the illustrated embodiment. All or part of the features of the first air gap 8 can be applied to the second air gap 9. In particular, there is no magnetic field sensor 5 within the second air gap 9.

[0094] The width of the first air gap 8 is smaller than the width of the second air gap 9. For example, the width of the first air gap 8 is at least 2 times, at least 5 times, or at least 10 times smaller than the width of the second air gap 9.

[0095] exist Figure 3The perspective view is shown in the middle. Figure 2 Device 2 is selected here. The following embodiment is chosen, which allows the determination of a current range, for example, up to 1000 A, flowing through the conductor 3. For this purpose, the magnetic core 4 has a width, for example, 35 mm in the x-direction, a height, for example, 20 mm in the y-direction, and a thickness, for example, 8 mm in the z-direction. The first air gap 8 has a width, for example, 1 mm, and the second air gap 9 has a width, for example, 6 mm. The dimensions given here and below are reference values ​​or guiding aids and may have tolerances.

[0096] Figure 4 Another embodiment of device 2 is shown. This embodiment may in particular include... Figure 2 and / or Figure 3 All or some of the features of the implementation methods described herein.

[0097] Especially in Figure 4 The device 2 has a third air gap 10, which at least partially interrupts, and in particular completely interrupts, the annular orientation 7 of the magnetic core 4. The third air gap 10 is neither adjacent to the first air gap 8 nor to the second air gap 9.

[0098] An additional magnetic field sensor 11 is located within the third air gap 10. This additional sensor is configured to generate an additional sensor signal 11a based on the magnetic flux caused by the current flowing through the wire 3 in the third air gap 10 and to provide it, for example, to the evaluation unit 6. The additional sensor signal 11a may be, for example, an additional voltage whose amplitude depends on the measured value of the magnetic flux in the third air gap 10.

[0099] In the illustrated embodiment, the gap width of the third air gap 10 is the same as the gap width of the first air gap 8. Therefore, sensor signal 5a and the other sensor signal 11a can be within similar value ranges. Similarly, by changing the gap width of the first air gap 8 in combination with the gap width of the third air gap 10, different value ranges for sensor signal 5a and the other sensor signal 11a can be achieved in a targeted manner.

[0100] In particular, sensor signal 5a may depend on the position of magnetic field sensor 5 within the first air gap 8 and additional sensor signal 11a may depend on the position of additional magnetic field sensor 11 within the third air gap 10.

[0101] exist Figure 5 The perspective view is shown in the middle. Figure 4Device 2 is selected here. The following embodiment is chosen, which allows the current range flowing through the conductor 3 to be determined, for example, up to 1000 A. For this purpose, the magnetic core 4 has a width of 35 mm in the x-direction, a height of 20 mm in the y-direction, and a thickness of 8 mm in the z-direction. The first air gap 8 has a width of 1 mm, and the second air gap 9 has a width of 6 mm. The third air gap 10 has a width of 1 mm.

[0102] Figure 6 Another embodiment of device 2 is shown. This embodiment may in particular include... Figure 2 , Figure 3 , Figure 4 and / or Figure 5 All or some of the features of the implementation method.

[0103] Especially in Figure 6 The device 2 has a ferromagnetic connector 12a. This ferromagnetic connector 12a completely bridges the second air gap 9; in other words, the magnetic core 4 is partially interrupted, particularly incompletely interrupted, at the second air gap 9 by means of the ferromagnetic connector 12a. This ferromagnetic connector is, in particular, made of a material with high magnetic permeability. For example, the magnetic core 4 can have the same material as the ferromagnetic connector 12a. The following embodiments are possible, in which the magnetic core 4 and the ferromagnetic connector 12a form a single unit, in other words, are designed as a single piece.

[0104] In particular, the width of the ferromagnetic patch 12a in the radial direction about the center of the magnetic core 4 can be small or very small compared to the gap width of the second air gap 9 and / or compared to the wall thickness of the magnetic core 4 in the radial direction. In other words, most of the volume of the second air gap 9 can be filled with a material with low permeability and only a small portion of the ferromagnetic patch 12a can be filled with a material with high permeability.

[0105] Furthermore, device 2 may have an additional ferromagnetic contact 12b. The characteristics of the ferromagnetic contact 12a may be wholly or partially adapted to the additional ferromagnetic contact 12b. Figure 6 and Figure 7 In this embodiment, the ferromagnetic contact 12a is located on the outer radius of the magnetic core 4, while the other ferromagnetic contact 12b is located on the inner radius of the magnetic core 4.

[0106] exist Figure 7 The perspective view is shown in the middle. Figure 6Device 2. Here, the following embodiment is selected, which allows for the determination of a current range, for example, up to 1000 A, flowing through the conductor 3. For this purpose, the magnetic core 4 has a width of 35 mm in the x-direction, a height of 20 mm in the y-direction, and a thickness of 8 mm in the z-direction. The first air gap 8 has a width of 1 mm, and the second air gap 9 has a width of 6 mm. The ferromagnetic contact 12a has a width of 0.5 mm perpendicular to the annular direction 7. The additional ferromagnetic contact 12b also has a width of 0.5 mm perpendicular to the annular direction 7.

[0107] Figure 8 , Figure 9 and Figure 10 Further examples of embodiments of device 2 are shown. These embodiments may include, in particular, […]. Figure 2 , Figure 3 , Figure 4 and / or Figure 5 All or some of the features of the implementation method.

[0108] In particular, device 2 has a ferromagnetic contact 12a, which is connected to... Figure 6 and Figure 7 The implementation in [the text] rotates 90° around the axis of rotation (see especially [the text]). Figure 10 ,and Figure 7 In contrast, the axis of rotation extends from one end of the second air gap 9 to the opposite end of the second air gap 9. The ferromagnetic connector 12a completely bridges the second air gap 9; in other words, the magnetic core 4 is not completely interrupted at the second air gap 9 by means of the ferromagnetic connector 12a.

[0109] In particular, the width of the ferromagnetic patch 12a in the extension direction of the conductor 3 can be small or very small compared to the gap width of the second air gap 9 and / or compared to the wall thickness of the magnetic core 4 in the extension direction of the conductor 3. In other words, the volume of the second air gap 9 is mostly filled with a material with low permeability and only a small portion of the ferromagnetic patch 12a is filled with a material with high permeability.

[0110] The magnetic core 4 can be implemented as a laminate or as a stack of laminates. In other words, the magnetic core 4 can have at least one layer 13a, 13b in the form of electrical steel sheets (especially stamped electrical steel sheets). In particular, the first layer 13a of the at least one layer 13a, 13b can have an electrical steel sheet different from the second layer 13b of the at least one layer 13a, 13b. For example, the ferromagnetic contact 12a can be part of the first layer 13a (see...). Figure 8 ), and the second layer 13b has a second air gap 9 at the same location (see Figure 9By connecting at least one electrical steel sheet—whose geometry corresponds to that of the first layer 13a—to at least one additional electrical steel sheet—whose geometry corresponds to that of the second layer 13b—a stack of sheets can be produced, as in… Figure 10 As shown in the diagram.

[0111] exist Figure 10 The perspective view is shown in the middle. Figure 8 and Figure 9 Device 2. Ferromagnetic contact 12a has a width of 0.3 mm in the direction of extension of conductor 3. The width of ferromagnetic contact 12a may correspond in particular to the thickness of a single electrical steel sheet (i.e., the thickness of the second layer 13b, for example) or a multiple of the thickness of the electrical steel sheet.

[0112] According to various embodiments of device 2, the magnetic core 4 can be implemented as partially saturable, for example, through a stepped design of the second air gap 9, a contracted design of the magnetic core 4, or a combination of multiple materials with corresponding properties. This allows for high sensitivity when a low current flows through the wire 3. When a medium current flows through the wire 3, the saturable region saturates and the magnetic core 4 exhibits transitional characteristics. When a high current flows through the wire 3, the saturable region can be deeply saturated, thereby closely approximating the magnetic properties of air and thus extending the effective second air gap. This reduces the magnetic field strength under high current conditions and therefore prevents overdriving of the magnetic field sensor 5.

[0113] By designing the size of the saturable region, it is possible to achieve sensitivity design in the low current range without calibration, as well as overdrive protection design for the magnetic field sensor 5 in the high current range.

[0114] The saturation characteristics of electrical steel sheets are typically given as curves depicting magnetic polarization (J) with respect to magnetic field strength (H). Alternatively, magnetic flux density (B) with respect to magnetic field strength can also be shown. These two diagrams can be considered equivalent in particular.

[0115] Within a low magnetic field strength range, electrical steel sheets can exhibit a sharp increase in the resulting magnetic flux density, corresponding to a high relative permeability (μ). r This rise can begin at, for example, a magnetic field strength of about 100 A / m and then transition to a significantly gentler rise, during which the material saturates. At high field strengths, the material can be considered nearly fully saturated, and the slope of the curve at this point corresponds to the permeability of free space (or the permeability of air), i.e., the absolute permeability μ0.

[0116] In many technical applications of magnetic materials (i.e., materials with a relative permeability greater than 1, such as electrical steel sheets or ferrite materials), saturation characteristics are considered detrimental. For example, in motors (electric motors, generators), reduced permeability leads to weakened coupling between the rotor and stator, resulting in decreased efficiency. Another effect is the increase in the power required for motor magnetization, i.e., an increase in magnetization demand. Similar effects can be observed in inductors or transformers. Here, the significantly increased current due to the saturation of magnetic components leads to increased losses in the surrounding circuitry. Increased losses can, in particular, cause damage to magnetic components or surrounding circuitry. This generally detrimental effect of magnetic material saturation can be utilized in arrangements used to detect current in measurement techniques.

[0117] In at least one embodiment of device 2, a ferromagnetic tab 12a is introduced into the second air gap 9. This ferromagnetic tab can also be referred to as the contraction portion of the magnetic core 4 in the second air gap 9 (see [link]). Figure 7 and Figure 10 Obviously, this contraction can also exist at any other or multiple locations on the magnetic core 4.

[0118] The contraction section can be made of the same material as the magnetic core 4. Alternatively, the ferromagnetic contact 12a may be made of a different material with different desired properties. One possibility is that the saturation of certain regions can be designed differently from that of other regions.

[0119] The ferromagnetic contact 12a (which may also be referred to below as the saturated contact) can be made of the same material as the laminate assembly. The following parameters can be considered as possible design parameters for device 2:

[0120] The gap width of the first air gap 8, which can also be referred to as the length or gap width of the sensor air gap, and / or

[0121] The gap width of the second air gap 9, which may also be referred to as the length or gap width of the saturation gap, and / or

[0122] The width of the saturated patch.

[0123] The width of the saturation contact can be considered, under a first-order approximation, as a design parameter used to design the current value that causes the saturation contact to saturate. The gap width of the second air gap 9 (which can also be called the length of the saturation contact) and the gap width of the sensor air gap can be considered as design parameters used to design the field strength of the magnetic field at the magnetic field sensor 5 under maximum current and when the saturation contact is approximately fully saturated.

[0124] There are different possibilities for elucidating the effect of the saturation patch length. For example, the length of the sensor air gap can be kept constant, and the effects of introducing saturation patches of different lengths or different gap widths of the second air gap 9 can be studied. Figure 11 The diagram shows simulation data for one embodiment of the device. Here, different effective total air gap lengths are generated after the saturation of the saturation tabs of different lengths.

[0125] exist Figure 11 , Figure 12 , Figure 13 and Figure 14 The graph shows simulation data for different embodiments of device 2. Here, the current (I) through wire 3 is shown on the x-axis. busbar The values ​​of / A are shown, and the resulting values ​​of the magnetic field strength (|H| / Am) caused by the corresponding values ​​of the current are displayed on the y-axis. -1 ).

[0126] Figure 11 (The variable total air gap length is the sum of the sensor air gap length (1.4 mm) and the saturation contact length as a parameter.) For example, it is shown that, within the range of small currents flowing through wire 3, when the current is less than approximately 50 A, the magnetic field strength that can be detected by measurement techniques in the sensor air gap by the magnetic field sensor 5 is remarkably similar in all four illustrated cases. The only critical factor for the characteristics within this range is the relatively short length of the sensor air gap. According to simulation data, the introduction of the saturation contact does not limit the sensitivity of the device in the case of small currents. Therefore, a good usable signal-to-noise ratio can be obtained even when the detected current is small.

[0127] Starting with currents greater than, for example, 100A, the saturation contact can be approximately fully saturated, thus, for example, in... Figure 11 No transition region is visible. If we assume that the magnetic field sensor 5 can detect, for example, magnetic fields up to 300 A / mm⁻¹ without overdrive, then the following relationship arises: without saturated contacts ( Figure 11 The curve marked with an asterisk (i.e., without the second air gap 9) indicates that the sensor signal 5a of the magnetic field sensor 5 can only be used to detect current, for example, when the current is less than or equal to 425 A. With the introduction of a 1mm length (…), Figure 11 The curve marked with a circle in the middle), 2 mm long ( Figure 11 (The curve marked with a diamond) or 3 mm long ( Figure 11 In the case of a saturated patch (with the curve marked by a square in the middle), the measurement range of device 2 can be extended to, for example, 600 A, 700 A or 775 A.

[0128] A secondary effect of longer saturation contacts and / or longer saturation gaps is a current shift towards higher values, at which the core 4 saturates overall. The advantage of device 2 is that it can reliably detect larger maximum currents using measurement techniques while maintaining the same sensitivity at low currents. This is in Figure 11 As can be seen, up to about 50A, all four options are very similar in implementation, so no signal degradation is expected at low current.

[0129] Observe below: the effect of the saturable region after the saturable patch saturates, while keeping the effective total air gap length constant. Here, the effective total air gap length is also approximately composed of the sum of the sensor air gap portion and the saturable region portion. In other words, during design, the effective total air gap length that is effectively present under high current can be chosen as a fixed value, which is approximately composed of the length of the sensor air gap and the length of the (saturated) saturable patch and / or the length of the saturable gap.

[0130] exist Figure 12 An alternative method for visualizing the effect of the saturation patch length is illustrated in a graph of simulated data, using a constant total air gap length (4.4 mm) as the sum of the sensor air gap length and the saturation patch length as a parameter. Figure 12 In the diagram, the simulation data without a saturated joint, i.e. without the second air gap 9, is marked with an asterisk; the simulation data with a saturated joint length of 1 mm is marked with a circle; the simulation data with a saturated joint length of 2 mm is marked with a rhombus; and the simulation data with a saturated joint length of 3 mm is marked with a square.

[0131] Therefore, a detailed partial image was selected at low current, specifically in the region where the saturated contact transitions from unsaturated to saturated. This clearly demonstrates that by altering the division of the sensor's air gap length and the length of the saturated contact, the sensitivity at low current can be improved.

[0132] The disadvantage of not changing the effective total air gap length is that the measurement range for high currents is limited when the measurement range is restricted by the magnetic field sensor 5.

[0133] However, this characteristic can be avoided by appropriately selecting the length of the sensor air gap and the length of the saturation contact. In other words, by appropriately selecting the length of the sensor air gap and the length of the saturation contact, a combination of high sensitivity at low current and extended measurement range at high current can be achieved.

[0134] Figure 13 (optimized single air gap length, which has higher sensitivity at low currents and extended measurement range at high currents) shows simulation data with such selected parameters. Figure 13In the diagram, the simulated data without a saturation patch, i.e. without a second air gap 9 and with a sensor air gap length of 4.4 mm, is marked with an asterisk; the simulated data with a sensor air gap length of 4.4 mm and a saturation patch length of 5 mm is marked with a circle; and the simulated data with a sensor air gap length of 2.5 mm and a saturation patch length of 12 mm is marked with a diamond.

[0135] Following the argument limited by magnetic field sensor 5, in this case, it is assumed that magnetic field sensor 5, for example, operates at 140 A / mm. -1 The drive is activated. In the arrangement structure according to the prior art, for example, a maximum current of approximately 640 A can be measured, which corresponds to... Figure 13 The curves are marked with an asterisk. In one embodiment of device 2—in which the length of the sensor air gap is the same and the length of the saturation patch is 5 mm—currents up to 1075 A can be measured with the same sensitivity over a small current range. Figure 13 (The curve marked with a circle in the middle).

[0136] By selecting a 2.5mm sensor air gap length and a 12mm saturation patch length, the sensitivity in the low current range can be improved while simultaneously extending the measurement range to 800A. Figure 13 (The curve is indicated by a diamond).

[0137] By using corresponding adaptive values, device 2 can be designed to achieve improved sensitivity at low currents while extending the measurement range at maximum currents. Figure 13 The example shown here is a device 2 whose analog data is graphically represented as curves marked with circles and diamonds.

[0138] As another characteristic to be studied, the effect of the width of the saturation patch is shown below. Figure 14 Simulation data are shown in (with variable saturation patch width as a parameter and a constant saturation gap length of 4.4 mm), demonstrating the characteristics of different arrangement structures. Figure 14 In the simulation, the width of the saturation patch is marked with a circle for 0.3 mm, a diamond for 0.6 mm, a square for 0.9 mm, and a cross for 1.2 mm. The simulation data corresponding to the width of the magnetic core 4 (i.e., the magnetic core of the device without a saturation gap, i.e., without a second air gap 9) is marked with an asterisk.

[0139] The range of measurable current, that is, for example, a region with a linear direction such as Figure 14As can be seen, a larger current can be applied by changing the width of the saturation contact. By changing the width of the saturation contact, the current that causes the contact to saturate can be adjusted. The larger the width of the saturation contact, the higher the value of the current that causes the contact to saturate.

[0140] The magnetic core 4 can be implemented as a stacked assembly. The stacked assembly of the magnetic core 4 can be made of multiple, for example, stamped electrical steel sheets. Figure 8 An example of the shape of this electrical steel sheet is given. This electrical steel sheet has a specified thickness (e.g., 0.3 mm), where using a thinner sheet allows for better suppression of eddy currents in the stack. Multiple electrical steel sheets can be joined together to form a stack by welding, bonding, or other methods. A notch in the upper leg of the magnetic core 4 forms a first air gap 8 for introducing the magnetic field sensor 5.

[0141] In device 2, a saturated contact can be generated simply by, for example, by: taking a portion of such electrical steel sheets according to... Figure 8 They are joined together, while the remaining electrical steel sheets are arranged according to... Figure 9 They join together. Here, a notch is placed at another location, and this notch is aligned with... Figure 8 The electrical steel sheets can be combined to form a narrow section in the lamination assembly.

[0142] This laminated structure also allows for the combination of electrical steel sheets with different material properties. For example, electrical steel sheets that should saturate under a selected current can be selected based on their corresponding material properties, thus forming a saturated contact. Here, the saturated contact, i.e., according to... Figure 8 The electrical steel sheets can be arranged either centrally within the lamination assembly or outside the center. According to... Figure 8 and Figure 9 It is also conceivable that the electrical steel sheets can be arranged in a continuous or discontinuous alternating manner.

[0143] In one embodiment of device 2, a current of 25A can induce approximately 500mVs / m in the saturated contact. -2 The magnetic flux density is 500 mT. At this current, the saturable region can remain unsaturated at the saturation junction. The magnetic field generated in the sensor's air gap can, for example, correspond to 17 A / mm². -1 .

[0144] At a current of 250A, 1.8Vsm can be induced in the saturated junction. -2 The magnetic flux density value is 1.8T. Unlike the case at 25A, the saturable region can be fully saturated at 250A. In this case, the magnetic field value in the sensor air gap can be approximately 100A / mm. -1 .

[0145] The saturation of the entire saturation patch can well approximate the magnetic properties of a vacuum. The length of the saturation patch can therefore contribute to the total air gap length and affect the field strength in the sensor air gap under high current, especially from the point where the saturation patch saturates.

[0146] When using the magnetoresistive model, it can be considered that the sum of the length of the sensor air gap and the length of the saturation patch, i.e., the length of the saturation gap, can be shorter than the effective total air gap length.

[0147] List of reference numerals

[0148] 1 vehicle

[0149] 2 devices

[0150] 3 wires

[0151] 4 magnetic cores

[0152] 5 magnetic field sensors

[0153] 5a sensor signal

[0154] 6 assessment units

[0155] 7. Circular Direction

[0156] 8 First air gap

[0157] 9 Second air gap

[0158] 10 Third air gap

[0159] 11. Other magnetic field sensors

[0160] 11a Other sensor signals

[0161] 12a ferromagnetic connector

[0162] 12b additional ferromagnetic contacts

[0163] 13a First Layer

[0164] 13b Second Layer

Claims

1. A device (2) for determining the current flowing through a wire (3) in a vehicle (1), wherein The device (2) has a magnetic core (4) designed to be used to wrap around the conductor (3) in a ring. The magnetic core (4) is at least partially interrupted along the annular direction (7) by the first air gap (8); The device (2) has a magnetic field sensor (5) located within a first air gap (8) and the magnetic field sensor is configured to generate a sensor signal (5a) based on the magnetic flux caused by the current in the first air gap (8). The magnetic core (4) is at least partially interrupted along the annular direction (7) by the second air gap (9); The gap width of the first air gap (8) is smaller than the gap width of the second air gap (9); and The device (2) has an evaluation unit (6) configured to determine the actual value of the current flowing through the conductor (3) based on the sensor signal (5a).

2. The apparatus (2) according to claim 1, wherein, The magnetic core (4) is at least partially interrupted along the annular direction (7) by the third air gap (10); The device (2) has an additional magnetic field sensor (11) located within the third air gap (10) and the additional magnetic field sensor is configured to generate an additional sensor signal (11a) based on an additional magnetic flux caused by an electric current in the third air gap (10). The gap width of the third air gap (10) is smaller than the gap width of the second air gap (9); and The evaluation unit (6) is configured to determine an additional actual value for the current flowing through the conductor (3) based on the additional sensor signal (11a).

3. The apparatus (2) according to any one of the preceding claims, wherein, The device (2) has a casting material and the magnetic field sensor (5) is surrounded by the casting material and / or the magnetic core (4) is at least partially surrounded by the casting material.

4. The apparatus (2) according to any one of the preceding claims, wherein, The second air gap (9) is completely filled with non-magnetic material.

5. The apparatus (2) according to any one of claims 1 to 3, wherein, The device has a ferromagnetic connector (12a) that bridges the second air gap (9) along the annular direction (7).

6. The apparatus (2) according to claim 5, wherein, The cross-sectional area of ​​the ferromagnetic contact (12a) is less than 20% or less than 5% of the cross-sectional area of ​​the magnetic core (4) at the second air gap (9).

7. The apparatus (2) according to any one of the preceding claims, wherein, The magnetic core (4) has a lamination group and / or the magnetic core (4) is implemented as a lamination group and / or the magnetic core (4) is implemented as a lamination.

8. The apparatus (2) according to any one of claims 7 and 5 or 6, wherein, The stacked assembly has the ferromagnetic tab (12a).

9. The apparatus (2) according to any one of the preceding claims, wherein, The magnetic field sensor (5) has a Hall sensor or a Hall sensor.

10. A vehicle (1), said vehicle having a wire (3) and a device (2) according to any one of the preceding claims, wherein, The magnetic core (4) of the device (2) is circularly wrapped around the wire (3).

11. The vehicle (1) according to claim 10, wherein, The vehicle has a fully electric drive system or a hybrid drive system with electrical subsystems, wherein the device (2) is a component of the electric drive system or the hybrid drive system.

12. A method for determining the current flowing through a wire (3) in a vehicle (1) using the apparatus (2) according to any one of claims 1 to 9, wherein, The magnetic core (4) of the device (2) is circularly wrapped around the wire (3). A sensor signal (5a) is generated based on the magnetic flux caused by the current in the first air gap (8); and The actual value of the current flowing through the conductor (3) is determined based on the sensor signal (5a).

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