Sensor device with sensor and current converter

Abstract

The invention relates to a sensor device (200) comprising: a sensor (210); a circuit carrier (220); a current supply for the sensor (210) and a circuit for detecting an output signal (U) generated by the sensor (210) H ) conductor segments (230, 231, 233, 234), the sensor (210) being connected to the circuit carrier (220) by means of the conductor segments; and a supply and reading device (225), wherein two of the conductor segments (230, 231) are electrically connected at corresponding contact points (235, 236) on the circuit carrier (220) by means of a capacitor (C1), so that the two conductor segments (230, 231), the capacitor (C1) and the sensor (210) form a component of an electrical circuit (L1). The present invention also relates to a current transformer and the use of such a sensor device (200).

Description

Technical Field

[0001] The present invention relates to a sensor arrangement comprising a sensor, a current transformer comprising such a sensor arrangement, and the use of such a sensor arrangement. Background Art

[0002] Converters are used to control or operate electric motors, for example in hybrid or electric vehicles. Converters are generally suitable and designed to operate the motor both motorically and generator-wise, depending on the current requirements. Synchronous motors, for example, operate with three-phase AC current, so three phase lines are provided between the corresponding connections in the converter (also called an inverter) and the motor. To control the motor, the currents in or on the phase lines must generally be measured.

[0003] The current measurement required for this purpose can be performed, for example, according to the conventional principle of current sensors, in which a Hall sensor is inserted into the air gap of a so-called flux concentrator. The flux concentrator (typically made of or comprising a ferromagnetic material) has the task of concentrating, intensifying, and homogenizing the magnetic field generated, for example, by the current in the phase line (or of course also in other ways), so that the Hall sensor can provide values that are as accurate as possible.

[0004] In this case, the Hall effect sensor can be connected to a printed circuit board or a conventional circuit board, for example, via a pin strip (in a so-called SIP or single in-line package). Due to the increasing intermediate circuit voltage and the increasingly rapid switching processes in the converter, relatively large, previously unnoticed, interferences occur. In particular, the Hall effect sensor, between the conductor segments for connection to the printed circuit board (e.g., two supply pins), spans a surface through which the magnetic flux lines of the magnetic field to be measured pass. Since the magnetic flux, which typically varies over time, passes through the magnetic field, a voltage is induced in this surface. The magnitude of this voltage is proportional to the surface area penetrated, the strength of the magnetic field, and the frequency of the signal.

[0005] Typically, the currents to be measured themselves usually do not have very high frequencies, for example, less than 10 kHz. However, with each switching process of the power electronics in the converter, parasitic capacitances (e.g., shielding capacitances of the phase lines and / or capacitances of the load or motor to the housing or ground) must be recharged. The currents required for this also flow through the phase lines. The resulting magnetic field not only penetrates the Hall sensor but can also penetrate other surfaces between the conductor tracks and, at frequencies exceeding 1 MHz, for example, can induce relevant interference voltages between the sensor legs (pins).

[0006] If there is little damping, an oscillation occurs, which can have a higher frequency, for example, exceeding 1 MHz. The larger the capacitance and the higher the intermediate circuit voltage switched to the capacitance during the switching process, the greater the current amplitude generated by the oscillation. Depending on the damping, the oscillation can include only a few cycles (for example, fewer than 5) or a larger number of cycles (for example, more than 20) before it decays to a low value.

[0007] The voltage induced between the two conductor sections of the Hall sensor due to the relatively high-frequency oscillation process is thus modulated onto the supply voltage of the Hall sensor. Consequently, the Hall sensor may, if necessary, respond to the output pin (i.e., the terminal for detecting the voltage induced in the Hall sensor, i.e., the Hall voltage) with a non-average-free interference signal for a certain period of time (typically a few microseconds from the switching process), and the voltage signal to be read, which should correspond to the level of the current to be measured, is distorted or falsified. Summary of the Invention

[0008] According to the present invention, a sensor device having a sensor, a current transformer, and a use of the sensor device are proposed. Advantageous embodiments are the subject of the following description.

[0009] The present invention relates to a sensor device comprising: a sensor; a circuit carrier; a conductor segment for supplying the sensor with power and detecting an output signal generated by the sensor, the sensor being connected to the circuit carrier by means of the conductor segment; and a supply and readout device. The supply and readout device, which may also be arranged on the circuit carrier, serves in particular for supplying the sensor with current or voltage and for detecting and also reading out and, if necessary, evaluating the output signal, in particular a voltage or current signal, emitted by the sensor. The conductor segment may also include any pins on the sensor or on the sensor housing.

[0010] Such sensor arrangements are primarily used to measure arbitrary measured variables, such as current. However, particularly when measuring current (and also directly when measuring magnetic fields), the measurement can be negatively influenced by the magnetic field, as explained above. The present invention therefore exhibits particular advantages in current and magnetic field sensors, such as Hall sensors or sensors based on AMR (anisotropic magnetoresistance), GMR (giant magnetoresistance), TMR (tunnel magnetoresistance), IMC (integrated magnetic concentrator), or other magnetoresistive effects, particularly when current changes or, if appropriate, magnetic field changes are mapped to (particularly linear) voltage changes at the sensor output.

[0011] The sensor arrangement preferably also includes a flux concentrator with a gap, in particular an annular flux concentrator, which is preferably made of or comprises a ferromagnetic material. The sensor, in particular a magnetic field sensor, is arranged in the gap, more specifically, preferably such that the magnetic flux lines present in the gap are oriented perpendicular to the sensor plane of the typically flat sensor. The sensor arrangement can also be used in this manner to measure currents through conductors, for example, as previously mentioned with reference to phase currents in electric machines. Independently of this, however, the principle underlying the present invention does not depend on how high-frequency disturbances in the magnetic field penetrating the sensor are generated.

[0012] In the proposed sensor device, two of the conductor segments are now electrically connected at corresponding contact points on the circuit carrier via a capacitor (and in particular also via corresponding connecting lines between the contact points and the capacitor), so that the two conductor segments, the capacitor, and the sensor are components of an electrical circuit. These components can belong to a common first electrical circuit, or to two different electrical circuits, as will be explained in more detail below. In the case of a common electrical circuit, the first electrical circuit then includes the conductor segments, the contact points, and the capacitor, and in particular also the sensor itself or a portion of the sensor. The contact points of the conductor segments on the circuit carrier are, in particular, locations on the circuit carrier, such as soldering points, at which the conductor segments are electrically and / or mechanically connected to the circuit carrier—and then to corresponding further conductors therein.

[0013] In this way, that is, by (directly) connecting the capacitors, preferably below the housing, the smallest possible surface area can be achieved in a particularly simple and cost-effective manner between two housing legs or two conductor segments (circuits) penetrated by the magnetic field. This, in turn, results in a lower effect of high-frequency interference in the magnetic field, i.e., a lower interference voltage modulated on the (supply) voltage applied to the conductor segments.

[0014] For example, a sensor such as in the sensor device described above may have four such conductor segments (which also include corresponding pins on the sensor or its housing), two of which are used to supply current to the sensor, and one (usually together with a ground conductor segment of the power supply) for detecting the output signal. The fourth pin or conductor segment often performs a special function. However, it is also conceivable to provide only three or even more conductor segments, for example, one conductor segment could be used for both current supply and voltage detection, as just mentioned.

[0015] Which two of these conductor segments are components of an electrical circuit can then be selected in principle depending on the requirements. It is also conceivable and sometimes particularly advantageous that multiple pairs of conductor segments are components of a corresponding electrical circuit with a corresponding capacitor.

[0016] For example, it is conceivable that two conductor sections (which are components of the electrical circuit) are used for the current supply of the sensor. However, it is also conceivable that one of the two conductor sections is used for the current supply of the sensor and one is used for detecting the output signal generated by the sensor.

[0017] The first electrical circuit, at least with respect to its arrangement on the circuit carrier, is preferably designed such that it encompasses the smallest possible surface area. If this relates to a portion of the electrical circuit on the circuit carrier, this means, in particular, that the shortest possible (electrical and geometric) connection between two contact points of a conductor segment should be selected. This can be, for example, a straight connection.

[0018] In this context, it is also expedient to arrange the capacitors geometrically between the corresponding contact points on the circuit carrier. This results in the area penetrated by the magnetic field being as small as possible, especially when the sensor device is designed to be outside the circuit carrier, mainly because the capacitors separate the electrical circuit from the remaining components. This arrangement of the capacitors geometrically means that the capacitors are arranged directly below the sensor or a possible housing of the sensor. Although these areas occupy a certain proportion It still exists, but is separated by the capacitor. The capacitor supports the voltage, so the effect of the connected line (not the sensor) is reduced.

[0019] In the case where two conductor segments with a capacitor arranged between them are used for the current supply of the sensor, this capacitor can also serve as a backup capacitor. However, due to the (direct) connection of the contact points and, in particular, the arrangement of the capacitor below the sensor or due to the minimal possible surface area of the electrical circuit, the influence of high-frequency interference in the magnetic field can be reduced.

[0020] The sensor device particularly preferably includes a second electrical circuit electrically connected to a capacitor and configured such that the current generated in the second electrical circuit by the magnetic field running through both the first and second electrical circuits cancels out interference exerted by the magnetic field on the sensor's output signal, i.e., reduces such interference. This can be achieved, for example, by canceling out the current generated by the magnetic field in the first electrical circuit, particularly the (high-frequency) AC component, in the second electrical circuit. However, it should be noted that such a sensor can, in principle, be very complex in design and that all conductor segments can have an influence, which may also require an increase in the voltage across the conductor segments to supply the current in order to reduce interference with the output signal. In this sense, this may mean that the current generated by the magnetic field in the first electrical circuit is amplified in the second electrical circuit. This second electrical circuit advantageously includes an additional capacitor to prevent possible short circuits.

[0021] According to the law of induction and assuming a constant geometry of the circuit, this current is caused exclusively by the (time-varying) magnetic field and therefore has in particular a (high-frequency) alternating current component.

[0022] To this end, it should be noted that, due to the connection of the second electrical circuit to the capacitor and, therefore, also to the first electrical circuit, the two currents or the charge transfer caused by the magnetic field superimpose, particularly at the node between the two circuits. This result can be influenced, for example, by a phase shift of the current generated in the second electrical circuit relative to the current generated in the first electrical circuit. To this end, an impedance (e.g., an inductor) can be provided in the second electrical circuit, the impedance being selected so as to minimize interference with the output signal of the sensor.

[0023] It may also be expedient to electrically connect the second electrical circuit to the capacitor in such a way that the direction of the current flowing from the further electrical circuit into the capacitor is phase-shifted by a value between 0° and 360°, for example, 180°, compared to the direction of the current flowing from the first electrical circuit into the capacitor. Furthermore, if necessary, an impedance or other passive components or elements may also be provided. The second electrical circuit, including any components, can generally be adapted to the (first) electrical circuit in such a way that undesirable interference in the Hall voltage is minimized.

[0024] Because interference can be particularly effectively reduced by the second circuit, it is also preferred that the first circuit include the two conductor segments and the sensor, but not the capacitor, and that the second circuit include the connection lines between the contact point and the capacitor and, optionally, also the capacitor. The second circuit is thus also designed such that the current generated in the second circuit by the magnetic field running through both the first and second circuits cancels out interference imparted by the magnetic field to the output signal of the sensor. The wires can then cross, for example, at one or more locations, thereby creating a transition from the first circuit to the second circuit.

[0025] In this case, the second electrical circuit can include (possibly only one) capacitor, which can then be used as a backup capacitor depending on the situation, as already explained. However, it is also conceivable that the capacitor, while electrically closing the second electrical circuit, is located outside the circuit plane, i.e., is not part of either the first or the second electrical circuit, as will be illustrated in particular in the figures using the following exemplary embodiments. The aforementioned embodiments with a second electrical circuit, which can generate a voltage that cancels the voltage generated in the first electrical circuit and thus reduces interference, also apply here.

[0026] It may be expedient to also provide a third electrical circuit, which is also constructed in such a way that the current generated in the second and third electrical circuits by the magnetic field simultaneously passing through the first, second and third electrical circuits cancels out the interference exerted by the magnetic field on the output signal of the sensor.

[0027] The present invention also relates to a converter for an electric machine, comprising at least one sensor arrangement according to the invention, which is provided for detecting phase currents.

[0028] Furthermore, the present invention relates to the use of the sensor device according to the invention for detecting phase currents by means of a current converter during operation of an electric machine.

[0029] Further advantages and configurations of the invention are apparent from the description and the accompanying drawings.

[0030] The invention is schematically illustrated in the drawings using exemplary embodiments and is explained below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A current transformer is schematically shown in which the sensor device according to the invention can be used;

[0032] Figure 2 A sensor device according to the invention is schematically shown in a preferred embodiment;

[0033] Figure 3 A sensor device according to the invention is schematically shown in another preferred embodiment;

[0034] Figure 4 A sensor device according to the invention is schematically shown in another preferred embodiment;

[0035] Figure 5 A sensor device according to the invention is schematically shown in another preferred embodiment;

[0036] Figures 6 to 11 The sensor device according to the invention is schematically shown in various further preferred embodiments. DETAILED DESCRIPTION

[0037] exist Figure 1 Schematically shows a converter 110 , which is designed as a bridge inverter, for example, in which the sensor device according to the invention can be used and which serves to control the electric machine 100 .

[0038] The converter 110 has two DC voltage terminals 131, 132, which are connected in a conventional manner to, for example, six semiconductor switches 120, such as MOSFETs, in addition to an intermediate circuit capacitor 135. Phases of the electric machine 100, each designated P1, P2, or P3, are connected between two of the semiconductor switches 120.

[0039] It should be mentioned here that the converter can be operated not only as an inverter but also, in particular, as a rectifier, so that the electric machine as a whole can be operated both motoringly and generator-wise.

[0040] Furthermore, the converter 110 is connected, for example, to an onboard electrical system 170 in a vehicle with its DC voltage connections 131, 132. Further components or electrical consumers are typically connected to the onboard electrical system 170, but are not shown here for the sake of clarity.

[0041] During operation of the converter 110, the individual semiconductor switches 120 are now driven in a suitable manner for opening or closing by means of a drive circuit or a drive unit 150. Under conventional control, for example, one switch per branch is always closed and another switch is always open. dc Converted into AC voltage.

[0042] Furthermore, a preferred embodiment of a sensor device 200 according to the invention is shown as an example, by means of which the phase current, ie the current flowing in phase P1, can be detected or measured. Of course, further such sensor devices can also be provided for other phases.

[0043] The converter 110 and the control unit 150 may together form the power electronics 140 for the electric machine 100 or may be part of such power electronics. The sensor device 200 may also be part of the power electronics.

[0044] exist Figure 2 Schematically, a sensor device 200 according to the invention is shown in a preferred embodiment. Sensor device 200 comprises, for example, a sensor 210, designed here as a Hall sensor, which is electrically conductively connected and fixed to corresponding contacts (one of which is designated by reference numeral 235) on a printed circuit board 220 as a circuit carrier by means of conductor segments (one of which is designated by reference numeral 230).

[0045] The conductor segments serve to supply current to the Hall sensor 210 and to detect the Hall voltage generated by the Hall sensor 210 , as will be explained in greater detail below, for example by means of a supply and readout device 225 arranged on the printed circuit board 220 and electrically connected accordingly.

[0046] Sensor device 200 also includes an annular flux concentrator 240, which is made of a ferromagnetic material, such as iron, and has a gap 241. Hall sensor 210 is arranged in this gap 241 (in which the magnetic flux lines of a magnetic field B formed in the flux concentrator are particularly straight, when a current flows, for example, in a line passed through the central opening of flux concentrator 240). In this way, such a magnetic field can, in principle, be detected particularly simply and accurately.

[0047] Furthermore, it can be seen that in such a sensor arrangement with Hall sensors and flux concentrators, the conductor segments are also located in the magnetic field B, but the magnetic field B also penetrates (if necessary to a lesser extent) the printed circuit board 220 .

[0048] exist Figure 3 Schematically shows a sensor device 200 according to the invention in another preferred embodiment, more precisely as a circuit diagram. Figure 2 The sensor device shown in FIG.

[0049] The Hall sensor 210 arranged in the housing 211 is connected to the printed circuit board 220 by means of, for example, four conductor segments 230, 231, 233 and 234. Here, the conductor segments 230 and 231 are used to supply current to the Hall sensor 210, that is, the current I S By means of the conductor segment (and Figure 2The supply and reading device shown in FIG) can flow through the Hall sensor 210 or be applied to the Hall sensor.

[0050] The conductor segment 233 or 234 (together with the grounded conductor segment of the power supply) is used to detect the Hall voltage U H , the Hall voltage in the presence of magnetic field B and current I S Of course, other types of sensors also have other output signals as Hall voltages. Regardless of the type of sensor, the output signal is usually also processed, so that, for example, a digitally generated ratiometric signal with an average voltage of 2.5 V is output. The Hall voltage U can then be read or evaluated using a supply and reading device (not shown here for clarity). H .

[0051] A capacitor C1, which also serves as a backup capacitor, is connected between the two contact points 235 and 236, at which the conductor segments 230 and 231 are connected to a printed circuit board (not shown here) (thus, for example, the power supply feed point for the sensor). In this way, a (closed) first electrical circuit L1 is formed, which includes capacitor C1, conductor segments 230 and 231, and part of Hall sensor 210.

[0052] Furthermore, a second electrical circuit L2 is provided, which comprises a further capacitor C2 and two impedances Z1 and Z2 and is electrically connected to the capacitor C1. The second electrical circuit L2 is constructed on a printed circuit board, for example, using suitable conductor tracks (e.g., copper). It should be noted that in the illustration shown, the electrical circuits L1 and L2 are arranged in one plane, but in a practical embodiment, the first electrical circuit forms an angle of approximately 90° with the second electrical circuit L2, for example, as shown by Figure 2 As can be seen, the second electrical loop L2 can be formed on the left or on the right with respect to the conductor segment or the contact point.

[0053] The second electrical loop L2 is penetrated by the magnetic field B at the selected surface on the printed circuit board and between the two conductor segments 230, 231 (in this example, the conductor segments for current supply). At the capacitors C1 and C2, the induced voltage U ind,1 and U ind,2 At the supply terminal of the Hall sensor, the induced voltage U ind,H This is indicated by the circular arrow.

[0054] Capacitor C1 can be used to support the supply voltage for the Hall sensor. Furthermore, the area of the first electrical loop L1, in which parasitic interference voltages are induced by high-frequency magnetic fields, is kept as small as possible between the conductor segments by arranging capacitor L1 as directly below the Hall sensor as possible on the printed circuit board.

[0055] Therefore, the induced interference voltage U ind,1 and U ind,H Here, as already mentioned, it should be noted that the capacitor C1 should be installed as directly as possible below the Hall sensor 210 or its housing 211 (at Figure 2 at the height of the contact point 235).

[0056] The additional capacitor C2 in the second electrical circuit L2 serves to prevent short circuits on the affected supply lines or other pins or conductor segments. Impedances Z1 and Z2 can be used to provide additional passive components in order to generate an impedance in the second electrical circuit L2 that positively influences the voltage U ind,1 of the and therefore the phase and / or amplitude of the current induced thereby.

[0057] The induced voltage at capacitor C1 can be set as follows: ind,1 The amplitude, phase, and, if necessary, frequency (i.e., the self-resonance of the electrical circuit) of the second electrical circuit L2 are optimized to minimize erroneous responses of the Hall sensor to interfering (high-frequency) magnetic fields. In other words, the second electrical circuit L2 is designed so that the current (or charge transfer) generated in the second electrical circuit L2 by the magnetic field B that simultaneously passes through both electrical circuits cancels out any interference that the magnetic field (B) imparts to the sensor's output signal.

[0058] Here, voltages are induced due to the law of induction. At first, these voltages do not drop across the capacitors, but rather across the inductors (every surface always has an inherent inductance, regardless of the structural element). Only then does a current build up, which can cause a charge transfer in the capacitor. This changes the voltage across the capacitor (larger capacitors have smaller voltage changes). Therefore, we can speak of an induced voltage across the capacitor.

[0059] This generally does not necessarily involve supply pins or conductor sections for the current supply of the Hall sensor; other signal pins or conductor sections can also be provided with loops, as described.

[0060] exist Figure 42 shows schematically a sensor device 200 ′ according to the invention in another preferred embodiment, also as a circuit diagram. The sensor device 200 ′ corresponds largely to the sensor device 200 , so reference can be made to the description there.

[0061] and press Figure 3 In contrast to the embodiment of the present invention, the second electrical circuit L2 is electrically connected to the capacitor C1 in a cross-connected manner, so that the voltage U ind,1 The phase of the Figure 3 If necessary or desired, the impedance can be adjusted accordingly. The circulating voltage induced in the surface of the second loop L2 affects the structural element by being rotated or shifted by 180°. This means that any previous amplification of the output interference can now be attenuated, more precisely, due to the 180° shift. However, it should be noted that the value of 180° is purely exemplary and serves for illustrative purposes.

[0062] Due to the generally complex internal behavior and structure of the sensor device or the corresponding sensor chip, different variants of the electrical circuit, as explained above by way of example, can be used to improve the measurement signal.

[0063] exist Figure 5 Schematically, a sensor device 200 ″ according to the invention is shown in another preferred embodiment, also as a circuit diagram. The sensor device 200 ′ corresponds largely to the sensor device 200 ′, so that reference can be made to the embodiments there.

[0064] But with the Figure 4 In contrast to the embodiment of the invention, the second electrical circuit L2 is arranged directly after the first electrical circuit and the capacitor C1 is a component of the second electrical circuit except for the contact points 235, 236 and the connecting lines 237, 238 of the capacitor C1, wherein the voltage U ind,1 The phase of the voltage U ind,H Move. You can also set Figure 3 such impedance, if needed or desired.

[0065] In other words, when pressing Figure 5 The implementation of Figure 4The capacitor C1 shown in FIG1 and the capacitor C2 therein take over its function instead. Therefore, the surface of the first electrical circuit L1 (including the sensor) should be defined by conductors, for example by bringing the conductors close together and then transitioning into the second electrical circuit L2, the task of which is to compensate for the voltage induced on the first surface by an opposite circulating voltage. The surface of the second electrical circuit does not have to be divided symmetrically between two conductors but can also be implemented in a different manner, for example using only one conductor, as will be shown below by way of example.

[0066] The (single) capacitor C1 then has the function of a backup capacitor for the supply voltage and, depending on which conductor section is part of the loop, of a smoothing capacitor for the output voltage.

[0067] The induced circulating voltage in the surface of the second loop L2 affects the structural element by rotating or shifting it by 180°. This means that any previous amplification of the output disturbance can now be attenuated, more precisely, due to the 180° shift. However, it should be noted that the value of 180° is purely exemplary and serves for illustrative purposes.

[0068] Due to the generally complex internal behavior and structure of the sensor device or the corresponding sensor chip, different variants of the electrical circuit, as explained above by way of example, can be used to improve the measurement signal.

[0069] exist Figures 6 to 11 , wherein only some of the components are labeled with reference numerals. In particular, the following exemplary embodiments will illustrate the possible configurations of a second and, if necessary, a third electrical circuit, also taking into account the positioning of capacitor C1. Here, as in the previous examples, a first electrical circuit is formed between two conductor segments 230, 231. As mentioned, this first electrical circuit can also be formed between other conductor segments.

[0070] The second side of the second electrical circuit L2 should preferably always be close to the sensor or Hall sensor 210 so that the magnetic field is sufficiently large for this second side. The second side should be as large as possible as the first side of the first electrical circuit L1. However, a positive effect can also be achieved with smaller sides. Figure 6 , an example is shown in which the second electrical circuit is designed such that its (second) surface is smaller than the (first) surface of the first electrical circuit L1. The second electrical circuit is primarily formed by the connecting line 237. Furthermore, capacitor C1 is not part of the second electrical circuit L2, which is not critical for the functionality of either the second electrical circuit L2 or capacitor C1.

[0071] exist Figure 7 In the example of FIG, the second electrical circuit L2 is configured such that its (second) surface corresponds approximately to the (first) surface of the first electrical circuit L1 .

[0072] exist Figure 8 In the example of FIG, the second electrical circuit L2 is configured such that its (second) surface corresponds approximately to the (first) surface of the first electrical circuit L1 .

[0073] exist Figure 9 In the example of FIG, the second electrical circuit L2 is configured such that its (second) surface is smaller than the (first) surface of the first electrical circuit L1. The second electrical circuit is primarily formed by connecting lines 238. The connecting lines 238 intersect to form a loop.

[0074] exist Figure 10 In the example of , in addition to the second electrical circuit, a third electrical circuit L3 is also provided, wherein the second and third electrical circuits are respectively configured such that the (second or third) surface of the second and third electrical circuits corresponds approximately to half of the (first) surface of the first electrical circuit L1. The second electrical circuit is mainly formed by the connecting line 237, and the third electrical circuit is formed by the connecting line 238. As in Figure 9 As in the example of FIG, each of the connecting lines 237, 238 crosses so as to form a corresponding loop.

[0075] exist Figure 11 In the example of FIG, the second electrical circuit L2 is configured such that its (second) side corresponds approximately to the (first) side of the first electrical circuit L1. The second electrical circuit is primarily formed by connecting lines 237. Here, the connecting lines 238 cross to form a loop.

Claims

1. A sensor device (200, 200') comprising: a sensor (210); a circuit carrier (220); a current supply for the sensor (210) and a circuit for detecting an output signal (U H ), by means of which the sensor (210) is connected to the circuit carrier (220); and a supply and reading device (225), in, Two of the conductor segments (230, 231) are electrically connected at corresponding contact points (235, 236) on the circuit carrier (220) by means of a capacitor (C1), so that the two conductor segments (230, 231), the capacitor (C1) and the sensor (210) are components of a first electrical loop (L1). The sensor device (200, 200') has a second electrical circuit (L2), which is electrically connected to the capacitor (C1) and is configured such that a current generated in the second electrical circuit (L2) by a magnetic field (B) simultaneously passing through the first electrical circuit (L1) and the second electrical circuit (L2) cancels out interference exerted on an output signal of the sensor by the magnetic field (B).

2. The sensor device (200, 200') according to claim 1, wherein The capacitor (C1) is arranged geometrically between the corresponding contact points (235, 236).

3. The sensor device (200, 200') according to claim 1 or 2, wherein The second electrical circuit (L2) comprises a further capacitor (C2).

4. The sensor device (200) according to claim 1 or 2, wherein The second electrical circuit (L2) includes at least one impedance (Z1, Z2).

5. The sensor device (200') according to claim 1 or 2, wherein The second electrical circuit (L2) is electrically connected to the capacitor (C1) such that the direction of the current flowing from the second electrical circuit (L2) into the capacitor (C1) is phase-shifted by a value between 0° and 360° compared to the direction of the current flowing from the first electrical circuit (L1) into the capacitor (C1).

6. The sensor device (200, 200") according to claim 1, wherein the second electrical circuit (L2) comprises a connection line between the contact point and the capacitor (C1).

7. The sensor device (200) according to claim 6, wherein The second electrical circuit (L2) includes the capacitor (C1).

8. The sensor device (200) according to claim 6 or 7 further comprises a third electrical circuit (L3), wherein the third electrical circuit is constructed so that the current generated in the second electrical circuit (L2) and the third electrical circuit by the magnetic field (B) that simultaneously passes through the first electrical circuit (L1), the second electrical circuit (L2) and the third electrical circuit (L3) cancels out the interference exerted on the output signal of the sensor by the magnetic field (B).

9. The sensor device (200, 200') according to claim 1 or 2, wherein The first electrical loop (L1), at least insofar as it is arranged on the circuit carrier (220), is designed such that it covers the smallest possible area.

10. The sensor device (200, 200') according to claim 1 or 2, wherein The two conductor segments (230, 231) are used for supplying current to the sensor (210).

11. The sensor device according to claim 1 or 2, wherein: One of the two conductor segments is used for supplying current to the sensor (210) and one is used for detecting an output signal generated by the sensor (210).

12. The sensor device (200, 200') according to claim 1 or 2, further comprising a flux concentrator (240), wherein the flux concentrator (240) comprises a gap (241), wherein: The sensor (210) is arranged in the gap (241).

13. The sensor device (200, 200') according to claim 12, wherein the flux concentrator (240) is made of a ferromagnetic material.

14. The sensor device (200, 200') according to claim 1 or 2, wherein The sensor (210) is designed as a magnetic field sensor.

15. The sensor device (200, 200') according to claim 14, wherein The sensor (210) is designed as a Hall sensor.

16. A current transformer (140) for an electric machine (100) having a sensor device (200, 200') according to any one of claims 1 to 15, the current transformer being designed to detect phase currents.

17. Use of the sensor device (200, 200') according to any one of claims 1 to 15 for detecting phase currents during operation of an electric machine (100) by means of a current converter (140).

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