current sensor

Abstract

The invention relates to a current sensor (1) comprising an electrically conductive busbar (2) having an upper side (21) and a lower side (22), wherein a measurement current to be measured flows through the busbar (2). An opening (8) is formed in the region of a taper (6) of the busbar (2). A carrier (10) of at least one magnetic detection element (4) is positioned in the opening (8) such that the at least one magnetic detection element (4) is positioned above the upper side (21) or above the lower side (22) of the busbar (2) relative to the busbar (2).

Description

Technical Field

[0001] This invention relates to a current sensor. Specifically, the current sensor includes a conductive busbar having an upper side and a lower side, through which a measuring current flows. A tapered portion is formed in the busbar, and at least one magnetic sensing element is allocated to the busbar in the region of the tapered portion. Background Technology

[0002] Published German patent application DE 10 2017 114 377 A1 discloses a current sensor. To determine the current flowing in a busbar, the busbar has through-holes into which the current sensor is joined. The busbar is positioned between two shielding plates to shield against external magnetic fields. The current sensor can be designed as a giant magnetoresistive (GMR) sensor, an anisotropic magnetoresistive (AMR) sensor, a tunneling magnetoresistive (TMR) sensor, or a Hall effect IC sensor. A disadvantage of the prior art is the need to provide additional shielding plates to homogenize the magnetic field in the sensor's region.

[0003] German patent application DE 10 2018 125 404 A1 describes a current sensor comprising three busbars. A first and second shielding plate, made of magnetic material, are arranged to sandwich the three busbars. Three magnetic sensing elements are each arranged between the three busbars and the first shielding plate to detect the magnetic field strength generated by the corresponding busbar. A conductive plate is arranged such that the three busbars are sandwiched together between the conductive plate and the second shielding plate. The conductive plate is made of a non-magnetic conductive material. Another disadvantage here is the complex and cost-intensive structure.

[0004] German patent application DE 10 2018 130 954 A1 discloses a current sensor for measuring the current flowing through a busbar. The current sensor includes a circuit board mounted on the busbar, the circuit board having a magnetic sensing element for detecting the strength of the magnetic field generated by the current flowing in the busbar. A housing comprising a first housing and a second housing is formed such that the busbar and a plate are sandwiched between them along the thickness direction of the busbar.

[0005] The German translation of international patent application WO 2019 / 181170, DE 11 2019 001 437 T5, discloses a current sensor having a conductive element, a magnetoelectric transducer, and a shield. A portion of the conductive element and the magnetoelectric transducer are located between the surfaces of a first shield and a second shield. A portion of the conductive element located between the first and second shields extends along an extension direction extending along the surface of the second shield. The second shield has two sides aligned in a transverse direction perpendicular to the extension direction, and a plurality of extensions extending toward the first shield on said sides and aligned and spaced apart from each other along the extension direction. The magnetoelectric transducer is located between the plurality of extensions aligned and spaced apart along the extension direction.

[0006] German patent application DE 10 2011 076 933 A1 describes a current sensor comprising a conductive element and at least two magnetic field sensors arranged on the conductive element and adapted to detect a magnetic field generated by a current flowing through the conductive element. The at least two magnetic field sensors are arranged on opposite sides of a line perpendicular to the direction of current flow in the conductive element. An insulating layer is disposed between the conductive element and the magnetic field sensors, and a conductor track is connected to the magnetic field sensors.

[0007] Compared to cored current sensors, conventional coreless current sensors typically have several drawbacks. For example, there is an undesirable dependence of the output signal on the frequency of the applied current (skin effect). Current sensors also lead to an undesirable dependence on the precise positioning of the sensor element relative to the busbar. Furthermore, coreless current sensors have a lower signal level compared to cored current sensors. In addition, coreless current sensors are sensitive to external magnetic fields.

[0008] The drawbacks of coreless current sensors can be mitigated through various measures. For example, the cross-section of the busbar in the sensor region can be reduced. By reducing the cross-section, the signal level (magnetic flux density) increases on the one hand, and frequency dependence decreases on the other. However, at the same time, the positioning of the current sensor becomes more critical.

[0009] Another option is to use additional magnetic flux-conducting material as a shield. Using additional magnetic flux-conducting material can homogenize the field in the area of ​​the magnetic detection element (sensor). Therefore, the precise positioning of the magnetic detection element is no longer critical.

[0010] The frequency response of a magnetic sensing element is corrected by additional external filters (resistors, inductors, capacitors). However, this typically reduces the output voltage range of the magnetic sensing element. For example, at least 6%–94% of the supply voltage is required for a “full” output voltage range, meaning the signal must be amplified again by an operational amplifier in a subsequent stage. Therefore, the filtering measures shift the DC operating point. Summary of the Invention

[0011] The present invention aims to create a current sensor that avoids all the disadvantages of the prior art, such as complex filtering measures or strong sensitivity to positioning tolerances, while still ensuring reliable measurement of the current carried in the busbar.

[0012] The above objective is achieved by a current sensor including the features of claim 1.

[0013] The current sensor is characterized by the presence of an opening in the tapered region. Furthermore, a carrier for at least one magnetic sensing element is positioned within the opening, such that the at least one magnetic sensing element is positioned above or below the busbar relative to the busbar.

[0014] The tapered section of the busbar helps reduce the skin effect. The skin effect is the current displacement effect in an electrical conductor through which high-frequency alternating current flows, meaning that the current density inside the conductor is lower than that on the surface. The skin effect is caused by the high conductivity of the material, which significantly attenuates the alternating field penetrating the conductor before it reaches the interior.

[0015] The skin effect occurs in conductors with a relatively thick skin depth, and also in conductive shielding and cable shielding. As frequency increases, the skin effect increases the transmission impedance of shielded cables and the shielding attenuation of conductive shielding, and also increases the cable's resistance.

[0016] To further reduce the skin effect and maintain a uniform field in the middle above or below the busbar, an opening (elongated hole) is milled or punched in the middle of the busbar.

[0017] The present invention is based on the objective of creating a current sensor that avoids all the disadvantages of the prior art while still ensuring reliable measurement of the current carried in the busbar.

[0018] The above objective is achieved by a current sensor including the features of claim 1.

[0019] According to the invention, an opening is formed in the region of the tapered portion. Evaluation can occur above or below the busbar. For this purpose, at least one magnetic sensing element is positioned above or below the upper side of the busbar relative to it. For this purpose, a carrier of at least one magnetic sensing element is positioned in the opening such that at least one magnetic sensing element is positioned above or below the upper side of the busbar relative to it.

[0020] The advantage of the current sensor according to the invention is that it requires no or only optical filtering and no operational amplifier. Furthermore, the current sensor according to the invention is insensitive to positioning tolerances relative to the busbar, or only slightly sensitive.

[0021] According to one embodiment, the carrier can hold two magnetic sensing elements. The carrier can have a cubic shape. When two magnetic sensing elements are provided on the carrier, it is designed such that, as the carrier passes through an opening in the busbar, one magnetic sensing element is positioned above the upper side of the busbar, and the other magnetic sensing element is positioned above the lower side of the busbar. When only a single magnetic sensing element is provided on the carrier, as the carrier passes through an opening in the busbar, the magnetic sensing element can be positioned either above the upper side or above the lower side of the busbar.

[0022] According to another embodiment, the carrier (plate) can be C-shaped, such that the carrier is clamped around the busbar, thereby positioning the two magnetic sensing elements accordingly above the upper side and above the lower side of the busbar. In the case where only a single magnetic sensing element is provided on the carrier (C-shape), if the carrier partially surrounds the busbar in the area of ​​the opening, the magnetic sensing element can be positioned above the upper side or above the lower side of the busbar.

[0023] According to the embodiments of the carrier described herein, the carrier may be designed as a circuit board, which, in addition to at least one magnetic detection element, also provides at least one electronic system for evaluating, filtering, and / or amplifying values ​​detected by at least one magnetic detection element.

[0024] The design advantage of a current sensor lies in its low positioning tolerance relative to a magnetic sensing element. If the magnetic sensing element is positioned at Y=0, the effect of this positioning tolerance is minimal there. However, if the magnetic sensing element is positioned there, it exhibits low-pass behavior, and the current sensor is more sensitive to low frequencies than high frequencies. To compensate for this, for example, an external high-pass filter can be used, which further attenuates low frequencies.

[0025] According to another embodiment of the present invention, the magnetic detection element above the upper side of the busbar and the magnetic detection element above the lower side of the busbar can be electronically combined to form a magnetic detection element.

[0026] This has the following advantages: the external magnetic field can be at least partially compensated through differential evaluation.

[0027] The carrier is positioned in the opening along the Z-coordinate direction, so that the carrier is oriented perpendicular to the busbar.

[0028] According to another embodiment of the invention, the opening in the tapered region is offset along the Y-coordinate direction relative to the axis of symmetry of the busbar. Therefore, the busbar forms a first connecting plate having a first thickness and a second connecting plate having a second thickness in the region of the opening, the first and second connecting plates being different in thickness.

[0029] This configuration offers the advantage of a further smoothed frequency response and the ability to save on operational amplifiers. Therefore, in this specific embodiment, the region of least mechanical tolerance influence is shifted to y = 2 mm. Since high-pass behavior is prevalent there, there is no need to reduce the output signal for lower frequencies. In other embodiments, the region of least mechanical tolerance influence can have different values.

[0030] At least one magnetic sensing element disposed on the carrier may be equipped with electronic devices for evaluating the measurements of the magnetic sensing element. For example, the electronic devices may include an additional filter circuit (buffer) that can be used to further adjust the frequency response.

[0031] The current sensor according to the invention can be used in the output busbar of a three-phase electric motor. In this case, there are particularly stringent requirements for the accuracy of the current sensor, which is achieved through the design according to the invention. Therefore, shielding or core material is omitted, and a "coreless" current sensor is used. Compared with current sensors with a core, it has no hysteresis near zero. Other advantages include lighter weight and lower cost. Attached Figure Description

[0032] Exemplary embodiments of the present invention and their advantages will now be described in more detail with reference to the accompanying drawings. The scale in the drawings does not always correspond to actual scale because, for better illustration, some shapes are simplified while others are shown enlarged relative to other elements. In the drawings:

[0033] Figure 1 shows a perspective view of a current sensor according to the prior art;

[0034] Figure 2 shows a perspective view of another embodiment of a current sensor according to the prior art;

[0035] Figure 3 A perspective view of a current sensor according to the present invention is shown;

[0036] Figure 4 A top view of an embodiment of the busbar according to the present invention is shown;

[0037] Figure 5 A possible implementation of a carrier for a magnetic detection element is shown;

[0038] Figure 6Another possible implementation of the carrier for the magnetic detection element is shown;

[0039] Figure 7 An embodiment of a carrier for positioning two magnetic detection elements relative to a busbar is shown;

[0040] Figure 8 A perspective view of another embodiment of the current sensor is shown, in which a carrier partially surrounds the busbar to position two magnetic sensing elements;

[0041] Figure 9 It shows Figure 8 A side view of the embodiment shown in the figure;

[0042] Figure 10 illustrates a possible implementation of an additional filter circuit in the prior art that can adjust the frequency response;

[0043] Figure 11 The compensated voltage signal from the magnetic detection element is shown compared to the uncompensated voltage signal;

[0044] Figure 12 A graphical representation of the tolerances for the positioning of the magnetic sensing element according to the present invention is shown;

[0045] Figure 13 The compensated voltage signals from the two magnetic sensing elements are shown compared to the uncompensated voltage signal; and

[0046] Figure 14 A graphical representation of the tolerances for the positioning of the two magnetic sensing elements according to the present invention is shown.

[0047] The same reference numerals are used for the same or equivalent elements in this invention. Furthermore, for clarity, only those reference numerals necessary for describing the respective figures are shown in the various figures. Detailed Implementation

[0048] Figure 1 shows a perspective and schematic diagram of a current sensor 1 according to the prior art. In the embodiment shown here, the magnetic sensing element 4 is arranged above the upper side 21 of the busbar 2 of the current sensor 1. The shield 3 is an additional magnetic flux conducting material that can homogenize the magnetic field in the region of the magnetic sensing element 4 of the current sensor 1. In the embodiment shown here, the shield 3 is U-shaped and arranged relative to the busbar 2 such that the shield 3 is opposite the lower side 22 of the busbar 2 and one leg 31 of the shield 3 is positioned opposite each side 23 of the busbar 2. Therefore, the exact positioning of the magnetic sensing element 4 relative to the busbar 2 is no longer critical.

[0049] Figure 2 shows a perspective view of another embodiment of the current sensor 1 according to the prior art. The busbar 2 has a tapered portion 6 on which the magnetic sensing element 4 is positioned. At the tapered portion 6, the cross-section 24 of the busbar 2 is reduced compared to the original cross-section 25. By reducing the cross-section 24, the signal level (magnetic flux density) increases on the one hand, and the dependence on frequency decreases on the other. However, at the same time, the positioning of the magnetic sensing element 4 becomes more critical.

[0050] Figure 3 A perspective view of the current sensor 1 according to the invention is shown. To further reduce the skin effect and simultaneously maintain a uniform field above or below the center of the busbar 2, an opening 8 (elongated hole) of the busbar 2 is introduced into the tapered portion 6 of the open busbar 2. The opening 8, having an elongated slot (elongated hole) shape, can be milled or stamped. The opening 8 is aligned longitudinally along the X-coordinate direction. The shape of the opening 8 (elongated hole with rounded corners) and the shape of the tapered portion 6 described herein should not be construed as limiting the invention. As shown in FIG2, the tapered portion 6 can also be circular or angular (see Figure 2). Figure 3 (In the implementation of the above). Alternatively, a rectangular opening 8 and a rectangular notch can also be considered as the tapered portion 6.

[0051] like Figure 3 As shown, the carrier 10 is positioned in the opening 8 along the Z-coordinate direction Z such that at least one magnetic sensing element 4 held on the carrier 10 is positioned above the upper side 21 of the busbar 2. The distance 5 between the magnetic sensing element 4 and the upper side 21 of the busbar 2 can be adjusted by positioning the carrier 10 in the opening 8. Although Figure 3 The diagram shows the positioning of the magnetic detection element 4 relative to the upper side 21 of the busbar 2, but this should not be construed as a limitation of the invention. According to the invention, the magnetic detection element 4 can be positioned relative to the lower side 22 or relative to the upper side 21 of the busbar 2. Similarly, the magnetic detection element 4 can be positioned relative to both the upper side 21 and the lower side 22 of the busbar 2. Therefore, the evaluation of the value detected by the magnetic detection element 4 does not occur within the opening 8, but rather above and / or below the busbar 2, as shown in... Figure 3 The information is indicated by the magnetic detection element 4. Appropriate electronics 11 are mounted on the carrier 10 for evaluation. As shown here, when the carrier is positioned in the opening 8, the carrier 10 is aligned perpendicular to the busbar 2. The electronics 11 on the carrier 10 can be a filter circuit. Alternatively, a ground surface can be optionally introduced on the carrier 10 to improve electromagnetic compatibility (EMC). This can also be used for further compensation of the frequency response.

[0052] Figure 4A plan view of an embodiment of the current sensor 2 according to the present invention is shown. An opening 8 is located in the region of the tapered portion 6, offset along the Y-coordinate direction relative to the axis of symmetry 12 of the busbar 2. This displacement of the opening 8 results in a first connecting plate 26 having a first thickness 27 and a second connecting plate 28 having a second thickness 29 in the region of the opening 8, the first and second connecting plates differing in thickness. This asymmetrical structure of the busbar 2 has the advantage of further smoothing the frequency response and saving on operational amplifier requirements.

[0053] Figure 5 and Figure 6 A possible embodiment of the carrier 10 for the magnetic detection element 4 is shown. In both figures, the magnetic detection element 4 is disposed on one side of the carrier 10. Similarly, the magnetic detection element 4 is provided with electronic devices 11 for evaluating the measured values. Figure 5 The implementation method described herein is used to position the magnetic detection element 4 relative to the upper side 21 of the busbar 2. Figure 6 The implementation method described herein is used to position the magnetic detection element 4 relative to the lower side 22 of the busbar 2.

[0054] Figure 7 Another embodiment of the carrier 10 for the two magnetic detection elements 4 is shown. Using this embodiment, measurements can be performed using the magnetic detection elements 4 located on the upper side 21 and the lower side 22 of the busbar 2. Electronic devices 11 are each assigned to one of the magnetic detection elements 4.

[0055] Figure 8 and Figure 9 Another embodiment of the carrier 10 is shown, which is C-shaped for positioning two magnetic sensing elements 4 relative to the busbar 2. Although the two magnetic sensing elements 4 are positioned relative to the busbar 2 together with the carrier 10 using the embodiment described herein, this should not be construed as limiting. With only one magnetic sensing element 4 attached to the C-shaped carrier 10, the magnetic sensing element can be positioned at a predetermined distance 5 along the Z-coordinate direction Z above the upper side 21 or the lower side 22 of the busbar 2.

[0056] The C-shaped carrier 10 has a base 15 and two legs 16. In the embodiment shown here, each leg 16 carries a magnetic sensing element 4. The C-shaped carrier 10 is positioned relative to the busbar 2 such that the carrier partially surrounds the busbar 2. This means that one leg 16 is positioned above the upper side 21 of the busbar 2, and the other leg 16 is positioned above the lower side 22 of the busbar 2. The magnetic sensing elements 4 held on the legs 16 are each positioned at a distance 5 from the upper side 21 or lower side 22 of the busbar 2 along the Z-coordinate direction.

[0057] FIG. 10 shows a possible embodiment of an additional filter circuit 40 in the prior art, by means of which the frequency response can be adjusted. For example, the frequency response of the current sensor 1 can be straightened by the filter circuit 40 comprising a resistor 41 and a capacitor 42. It is self-evident to those skilled in the art that inductors and active components, such as operational amplifiers, can also be used.

[0058] Figure 11 shows the compensated voltage signal from the magnetic sensing element 4 compared with the uncompensated voltage signal. Here, the ratio of the compensated voltage signal to the uncompensated voltage signal is plotted in % based on the positioning of the magnetic sensing element 4 along the Y coordinate direction Y. Four curves are plotted for different distances 5 (see Figure 3 ) of the magnetic sensing element 4 from the busbar 2 along the Z coordinate direction Z. The distance 5 of 3 mm is shown by a solid line. The distance 5 of 4 mm is shown by a dashed line. The distance 5 of 5 mm is shown by a dash-dotted line. The distance 5 of 6 mm is shown by a dash-dotted line and a double dash-dotted line.

[0059] Figure 12 shows a graphical representation of the tolerance for the positioning of the magnetic sensing element 4 of the present invention. With the current geometry, the positioning of the magnetic sensing element 4 relative to the busbar 2 already has small tolerances. In FIG. 10, the magnetic field strength in mT is plotted based on the positioning of the magnetic sensing element 4 along the Y coordinate direction Y. Four curves are plotted for different distances 5 (see Figure 3 ) of the magnetic sensing element 4 from the busbar 2 along the Z coordinate direction Z. The distance 5 of 3 mm is shown by a solid line. The distance 5 of 4 mm is shown by a dashed line. The distance 5 of 5 mm is shown by a dash-dotted line. The distance 5 of 6 mm is shown by a dash-dotted line and a double dash-dotted line. At y=0, all curves have a slight slope other than zero. In addition, the curves there are very close to each other. Therefore, the influence of positioning tolerances has the lowest effect there. However, in the case where the magnetic sensing element 4 is placed in the range from y=0 to approximately y=2 mm, the magnetic sensing element exhibits low-pass behavior (the magnetic sensing element 4 is more sensitive to low frequencies than to high frequencies). To compensate for this, for example, an external high-pass filter can be used, which additionally attenuates low frequencies. For the current case, this is necessary in the range of y<2 mm.

[0060] Figure 11 and Figure 12 described in the conditions occur for connection plates with different thicknesses (see Figure 4 ). From Figure 12 it can be seen that the range of 0<y<approximately 2 mm is relatively tolerant to positioning errors. From y>approximately 2 mm, there is no longer a need to increase the signal (see Figure 11 ), so that the optimal positioning of the magnetic sensing element 4 is given as y=2 mm.

[0061] Figure 13 shows the compensated voltage signals from two magnetic detection elements 4 compared with uncompensated voltage signals. Here, the ratio of the compensated voltage signal to the uncompensated voltage signal is plotted in % according to the positioning of the magnetic detection elements 4 along the Y coordinate direction Y. Four curves are plotted for different distances 5 of the magnetic detection elements 4 from the busbar 2 along the Z coordinate direction Z (see Figure 3 ). A distance 5 of 3 mm is shown by a solid line. A distance 5 of 4 mm is shown by a dashed line. A distance 5 of 5 mm is shown by a dash-dot line. A distance 5 of 6 mm is shown by a dash-dot line and a double dash-dot line. After the filter, an operational amplifier must be used to increase the signal to 100% again.

[0062] Figure 14 shows a graphical representation of the positioning tolerances for the two magnetic sensing elements 4 of the present invention. With the current geometry, the positioning of the magnetic detection elements 4 relative to the busbar 2 already has small tolerances. In Figure 14 , the magnetic field strength in mT is plotted according to the positioning of the magnetic detection elements 4 along the Y coordinate direction Y. Four curves are plotted for different distances 5 of the magnetic detection elements 4 from the busbar 2 along the Z coordinate direction Z (see Figure 3 ). A distance 5 of 3 mm is shown by a solid line. A distance 5 of 4 mm is shown by a dashed line. A distance 5 of 5 mm is shown by a dash-dot line. A distance 5 of 6 mm is shown by a dash-dot line and a double dash-dot line. All curves have a slope of zero at y=0. In addition, the curves there are very close to each other. Therefore, the influence of positioning tolerances has the lowest effect there. However, in the case where the two magnetic detection elements 4 are placed there, they have a low-pass behavior (the magnetic detection elements 4 are more sensitive to low frequencies than to high frequencies). To compensate for this, for example, an external high-pass that additionally attenuates low frequencies can be used. For this case, this is necessary in the range of -7 mm < y < +7 mm.

[0063] List of reference numerals

[0064] 1 Current sensor

[0065] 2 Conductive rail

[0066] 3 Shielding member

[0067] 4 Magnetic detection element

[0068] 5 Distance

[0069] 6 Tapering portion

[0070] 8 Opening

[0071] 10 Carrier member

[0072] 11 Electronic device

[0073] 12 Axis of Symmetry

[0074] 15. Base

[0075] 16. Legs

[0076] 21 upper side

[0077] 22 Lower side

[0078] 23 Side

[0079] 24. Reduced cross-section

[0080] 25 Original cross-section

[0081] 26 First connecting plate

[0082] 27 First Thickness

[0083] 28 Second connecting plate

[0084] 29 Second Thickness

[0085] 31 Legs

[0086] 40 Filter Circuit

[0087] 41 Resistor

[0088] 42 Capacitor

[0089] XX coordinate direction

[0090] YY coordinate direction

[0091] ZZ coordinate direction

Claims

1. A current sensor (1), comprising: A conductive busbar (2) has an upper side (21) and a lower side (22), through which the measurement current to be measured flows. The tapered portion (6) formed in the busbar (2), and At least one magnetic detection element (4) is assigned to the busbar (2) in the region of the tapered section (6). Its features An opening (8) is formed in the region of the tapered portion (6); and The carrier (10) of at least one magnetic detection element (4) is positioned relative to the opening (8) such that the at least one magnetic detection element (4) is positioned above the upper side (21) and / or below the lower side (22) of the busbar (2). The busbar (2) is planar in the region of the tapered section (6).

2. The current sensor (1) according to claim 1, wherein, The carrier (10) has a rectangular cube shape, and in the case of the magnetic sensing element (4), the magnetic sensing element is positioned above the upper side (21) or below the lower side (22) of the busbar (2), and in the case of two magnetic sensing elements (4), the two magnetic sensing elements are positioned above the upper side (21) and below the lower side (22) of the busbar (2) when the carrier (10) passes through the opening (8).

3. The current sensor (1) according to claim 2, wherein, The carrier (10) is positioned in the opening (8) along the Z coordinate direction (Z) and is oriented perpendicular to the busbar (2).

4. The current sensor (1) according to claim 1, wherein, The carrier (10) has a C-shaped shape, and in the case of the magnetic detection element (4), the magnetic detection element is positioned above the upper side (21) or below the lower side (22) of the busbar (2), and in the case of two magnetic detection elements (4), if the carrier (10) partially surrounds the opening (8) in the busbar (2), the two magnetic detection elements are positioned above the upper side (21) and below the lower side (22) of the busbar (2).

5. The current sensor (1) according to claim 1, wherein, The magnetic detection element (4) above the upper side (21) of the busbar (2) and the magnetic detection element (4) below the lower side (22) of the busbar (2) are electronically combined to form the magnetic detection element (4).

6. The current sensor (1) according to any one of claims 1-5, wherein, The opening (8) in the region of the tapered section (6) is offset in the Y-coordinate direction (Y) relative to the axis of symmetry (12) of the busbar (2), thereby the busbar (2) in the region of the opening (8) has a first connecting plate (26) with a first thickness (27) and a second connecting plate (28) with a second thickness (29) that are different in terms of thickness.

7. The current sensor (1) according to any one of claims 1-5, wherein, The opening (8) is an elongated hole that is milled or punched in the region of the tapered portion (6) of the busbar (2) aligned along the X coordinate direction (X).

8. The current sensor (1) according to any one of claims 1-5, wherein, The at least one magnetic detection element (4) arranged on the carrier (10) is equipped with electronic devices (11) for evaluating the measured value of the magnetic detection element (4).

9. The current sensor (1) according to any one of claims 1-5, wherein, The magnetic detection element (4) is assigned to each output side busbar (2) of the three-phase motor.

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