SENSOR DEVICE WITH SENSOR AND CURRENT CONVERTER

Abstract

The invention relates to a sensor device (200) having a sensor (210), having a circuit carrier, having conductor sections (230, 231, 233, 234) which serve for supplying electrical current to the sensor (210) and for detecting an output signal (U.sub.H) generated by the sensor (210) and by means of which the sensor (210) is connected to the circuit carrier, and having a supply and read-out device, wherein respective contact points (235, 236) of two of the conductor sections (230, 231) on the circuit carrier (220) are electrically connected by means of a capacitor (C.sub.1) such that the two conductor sections (230, 231), the capacitor (C.sub.1) and the sensor (210) form constituent parts of an electrical loop (L.sub.1), and to a current converter and to the use of such a sensor device (200).

Claims

1. A sensor device (200, 200′) comprising: a sensor (210), a circuit carrier (220), conductor sections (230, 231, 233, 234) for supplying current to the sensor (210) and for capturing an output signal (U.sub.H) generated by the sensor (210), which conductor sections connect the sensor (210) to the circuit carrier (220), and a supply and read-out apparatus (225), wherein respective contact points (235, 236) of two of the conductor sections (230, 231) on the circuit carrier (220) are electrically connected by means of a capacitor (C.sub.1), with the result that the two conductor sections (230, 231), the capacitor (C.sub.1) and the sensor (210) are constituent parts of an electrical loop (L.sub.1).

2. The sensor device (200, 200′) as claimed in claim 1, wherein the two conductor sections (230, 231), the capacitor (C.sub.1) and the sensor (210) are constituent parts of a common, first electrical loop (L.sub.1).

3. The sensor device (200, 200′) as claimed in claim 1, wherein the capacitor (C.sub.1) is geometrically arranged between the respective contact points (235, 236).

4. The sensor device (200, 200′) as claimed in claim 2, having a second electrical loop (L.sub.2) which is electrically connected to the capacitor (C.sub.1) and is designed in such a manner that a current flow, which is generated in the second electrical loop (L.sub.2) by a magnetic field (B) that permeates the first electrical loop (L.sub.1) and the second electrical loop (L.sub.2) at the same time, counteracts interference exerted on the output signal from the sensor by the magnetic field (B).

5. The sensor device (200, 200′) as claimed in claim 4, wherein the second electrical loop (L.sub.2) comprises a further capacitor (C.sub.2).

6. The sensor device (200) as claimed in claim 4, wherein the second electrical loop (L.sub.2) comprises at least one impedance (Z.sub.1, Z.sub.2).

7. The sensor device (200′) as claimed in claim 4, wherein the second electrical loop (L.sub.2) is electrically connected to the capacitor (C.sub.1) in such a manner that a direction of the current flow into the capacitor (C.sub.1) from the second electrical loop (L.sub.2) has a phase offset of a value between 0° and 360° with respect to a direction of the current flow into the capacitor (C.sub.1) from the first electrical loop (L.sub.1).

8. The sensor device (200, 200″) as claimed in claim 1, having a first electrical loop (L.sub.1), which comprises the two conductor sections (230, 231) and the sensor (210), and having a second electrical loop (L.sub.2) which comprises connection lines from the contact points to the capacitor (C.sub.1), wherein the second electrical loop (L.sub.2) is designed in such a manner that a current flow, which is generated in the second electrical loop (L.sub.2) by a magnetic field (B) that permeates the first electrical loop (L.sub.1) and the second electrical loop (L.sub.2) at the same time, counteracts interference exerted on the output signal from the sensor by the magnetic field (B).

9. The sensor device (200) as claimed in claim 8, wherein the second electrical loop (L.sub.2) comprises the capacitor (C.sub.1).

10. The sensor device (200) as claimed in claim 8, also having a third electrical loop (L.sub.3) which is designed in such a manner that a current flow, which is generated in the second and third electrical loops (L.sub.2) by a magnetic field (B) that permeates the first (L.sub.1), second (L.sub.2) and third electrical loops (L.sub.3) at the same time, counteracts interference exerted on the output signal from the sensor by the magnetic field (B).

11. The sensor device (200, 200′) as claimed in claim 2, wherein the first electrical loop (L.sub.1), at least insofar as it is formed on the circuit carrier (220), is designed in such a manner that it encloses an area which is as small as possible.

12. The sensor device (200, 200′) as claimed in claim 1, wherein the two conductor sections (230, 231) are used to supply current to the sensor (210).

13. The sensor device as claimed in claim 1, wherein, of the two conductor sections, one is used to supply current to the sensor (210) and one is used to capture the output signal generated by the sensor (210).

14. The sensor device (200, 200′) as claimed in claim 1, further comprising a flux concentrator (240) made of a ferromagnetic material and having a gap (241), wherein the sensor (210) is arranged in the gap (241).

15. The sensor device (200, 200′) as claimed in claim 1, wherein the sensor (210) is in the form of a magnetic field sensor.

16. A current converter (140) for an electrical machine (100), having at least one sensor device (200, 200′) as claimed in claim 1, which current converter is configured to capture a phase current.

17. The use of a sensor device (200, 200′) as claimed in claim 1 for capturing a phase current when operating an electrical machine (100) by means of a current converter (140).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 schematically shows a current converter in which a sensor device according to the invention can be used.

[0032] FIG. 2 schematically shows a sensor device according to the invention in one preferred embodiment.

[0033] FIG. 3 schematically shows a sensor device according to the invention in a further preferred embodiment.

[0034] FIG. 4 schematically shows a sensor device according to the invention in a further preferred embodiment.

[0035] FIG. 5 schematically shows a sensor device according to the invention in a further preferred embodiment.

[0036] FIGS. 6 to 11 schematically show sensor devices according to the invention in various further preferred embodiments.

DETAILED DESCRIPTION

[0037] FIG. 1 schematically illustrates a current converter 110 which is in the form of a bridge inverter, for example, in which a sensor device according to the invention can be used and which is used to control an electrical machine 100.

[0038] The current converter 110 has two DC voltage connections 131, 132 which, in addition to an intermediate circuit capacitor 135, are connected in a conventional manner to six semiconductor switches 120, for example MOSFETs, for example. A phase of the electrical machine 100, which is respectively denoted P.sub.1, P.sub.2 or P.sub.3, is connected between two of the semiconductor switches 120 in each case.

[0039] It should be mentioned at this point that the current converter cannot only be operated as an inverter but also, in particular, as a rectifier, with the result that the electrical machine as a whole can be operated both in a motor mode and in a generator mode.

[0040] The current converter 110 is also connected, by way of its DC voltage connections 131, 132, to a vehicle electrical system 170, for example in a vehicle. Further components or loads, which are not shown here however for the sake of clarity, are in turn typically connected to the vehicle electrical system 170.

[0041] During operation of the current converter 110, the individual semiconductor switches 120 are now actuated to open or close in a suitable manner by means of an actuation circuit or an actuation unit 150. During conventional actuation, one switch for each branch is always closed and the other is open, for example. In this case, a DC voltage U.sub.dc is converted into an AC voltage.

[0042] A preferred embodiment of a sensor device 200 according to the invention, which can be used to capture or measure a phase current, that is to say a current which flows in the phase P.sub.1, is also indicated by way of example. It goes without saying that further sensor devices of this type may be provided for the other phases.

[0043] In this case, the current converter 110 and the actuation unit 150 may together form power electronics 140 for the electrical machine 100 or may be part of such power electronics. In particular, the sensor device 200 may also be part of the latter.

[0044] FIG. 2 schematically illustrates a sensor device 200 according to the invention in one preferred embodiment. The sensor device 200 has, for example, a sensor 210 which is in the form of a Hall sensor here and is connected and fastened in an electrically conductive manner at a respective contact point, one of which is denoted 235, by means of conductor sections, one of which is denoted 230, on a printed circuit board 220 as a circuit carrier.

[0045] The conductor sections are used to supply current to the Hall sensor 210 and to capture a Hall voltage generated by the Hall sensor 210, as will be explained in yet more detail below, specifically, for example, by means of a supply and read-out apparatus 225 which is arranged on the printed circuit board 220 and is appropriately electrically connected.

[0046] The sensor device 200 also has a flux concentrator 240 which is annular here and is composed of a ferromagnetic material, for example iron, and has a gap 241. The Hall sensor 210 is arranged in this gap 241 in which flux lines of a magnetic field B, which forms in the flux concentrator if a current flows in a line routed through the central opening of the flux concentrator 240 for example, form in a particularly rectilinear manner. In this manner, such a magnetic field can be captured in a particularly simple and accurate manner, in principle.

[0047] It should also be recognized that, in the case of such a sensor device having a Hall sensor and a flux concentrator, the conductor sections are also located in the magnetic field B, but the magnetic field B also likewise permeates the printed circuit board 220 (albeit possibly to a lesser extent).

[0048] FIG. 3 schematically shows a sensor device 200 according to the invention in a further preferred embodiment, specifically as a circuit diagram. This may also be the sensor device shown in FIG. 2.

[0049] The Hall sensor 210 arranged in a housing 211 is connected to the printed circuit board 220 by means of four conductor sections 230, 231, 233 and 234, for example. In this case, the conductor sections 230 and 231 are used to supply current to the Hall sensor 210, that is to say a current flow Is can be applied through or to the Hall sensor 210 via said conductor sections (and with the supply and read-out apparatus shown in FIG. 2).

[0050] The conductor section 233 or 234 (together with that conductor section of the supply which is connected to ground) is used to capture a Hall voltage U.sub.H which is generated in the presence of a magnetic field B and the current Is. It goes without saying that, in the case of a different type of sensor, an output signal other than the Hall voltage is also present. Irrespective of the type of sensor, processing of the output signal is then generally also provided, with the result that, for example, a digitally generated, ratiometric signal with a center voltage of 2.5 V is output. The supply and read-out apparatus, which is not shown here for the sake of clarity, can then likewise be used to read out and evaluate the Hall voltage U.sub.H.

[0051] A capacitor C.sub.1 which is also used here as a back-up capacitor is connected between two contact points 235 and 236, at which the conductor sections 230 and 231 are connected to the printed circuit board (not shown here) (these are therefore feed-in points of the supply, based on the sensor, for example). This forms a (closed) first electrical loop L.sub.1 which comprises the capacitor C.sub.1, the conductor sections 230 and 231 and parts of the Hall sensor 210.

[0052] A second electrical loop L.sub.2 is also provided, which second electrical loop comprises a further capacitor C.sub.2 and two impedances Z.sub.1 and Z.sub.2 and is electrically connected to the capacitor C.sub.1. In this case, the second electrical loop L.sub.2 is formed on the printed circuit board, for example using suitable conductor tracks (for example made of copper). In this respect, it should be noted that, although the electrical loops L.sub.1 and L.sub.2 are in a plane in the illustration shown, the first electrical loop L.sub.1 is approximately at an angle of 90° with respect to the second electrical loop L.sub.2 in the actual embodiment, as is clear from FIG. 2. In this case, the second electrical loop L.sub.2 may be formed on the left-hand side or right-hand side with respect to the conductor sections or contact points.

[0053] The selected area of the second electrical loop L.sub.2 on the printed circuit board and the area between the two conductor sections 230, 231 (those for supplying current in this example) are permeated by the magnetic field B. Induction voltages U.sub.ind,1 and U.sub.ind,2 are dropped across the capacitors C.sub.1 and C.sub.2 and across the impedances. An induction voltage U.sub.ind,H is dropped across the supply connections of the Hall sensor. This is indicated by means of the circular arrows.

[0054] In this case, the capacitor C.sub.1 can be used to support the supply voltage for the Hall sensor. In addition, the area of the first electrical loop L.sub.1, in which a parasitic interfering voltage is induced in the case of high-frequency magnetic fields, is kept as small as possible between the conductor sections by arranging the capacitor C.sub.1 as directly as possible below the Hall sensor on the printed circuit board.

[0055] The induced interference voltages U.sub.ind,1 and U.sub.ind,H are therefore also kept as low as possible. As already mentioned, it should be ensured here that the capacitor C.sub.1 should be fitted as directly as possible below the Hall sensor 210 or its housing 211 (at the level of the contact point 235 in FIG. 2).

[0056] The further capacitor C.sub.2 in the second electrical loop L.sub.2 is used to avoid a short circuit on the supply lines or other pins or conductor sections which are intended to be influenced. The impedances Z.sub.1 and Z.sub.2 can be used to provide additional passive components in order to generate an impedance in the second electrical loop L.sub.2 which favorably influences a phase and/or amplitude of the voltage U.sub.ind,1 and thus the current flow caused thereby.

[0057] The amplitude, phase and possibly a frequency (that is to say the natural resonance of the electrical loop) of the induced voltage at the capacitor C.sub.1, that is to say U.sub.ind,1 can be set in such a manner that the erroneous reaction of the Hall sensor to the interfering (high-frequency) magnetic field is reduced. In other words, the second electrical loop L.sub.2 is therefore formed in such a manner that a current flow (or a charge transfer), which is generated in the second electrical loop L.sub.2 by a magnetic field B that permeates both electrical loops at the same time, counteracts interference exerted on the output signal from the sensor by the magnetic field (B).

[0058] In this case, a voltage is induced on account of the law of induction. Initially, these voltages are not dropped across the capacitances, but rather across the inductances (each area always has an inherent inductance, irrespective of the components). Current flows which give rise to charge transfers in the capacitors only then build up. As a result, the voltages across the capacitors change (if the capacitor is large, its voltage change is small). It is therefore possible to refer to induced voltages at the capacitors.

[0059] Generally, these need not be the supply pins or conductor sections for supplying current to the Hall sensor; other signals or pins or conductor sections may also be provided with a loop, as described.

[0060] FIG. 4 schematically illustrates a sensor device 200′ according to the invention in a further preferred embodiment, likewise as a circuit diagram. The sensor device 200′ largely corresponds to the sensor device 200, with the result that reference can be made to the statements there.

[0061] In contrast to the embodiment according to FIG. 3, the second electrical loop L.sub.2 is electrically connected to the capacitor C.sub.1 in a crossed manner here, with the result that the phase angle of the voltage U.sub.ind,1 is rotated through 180°. Impedances, like in FIG. 3, could also be provided here, if necessary or desired. The induced rotational voltage in the area of the second loop L.sub.2 rotates or shifts the components through 180°. This means that any previous amplification of output interference can now result in attenuation, specifically on account of the 180° shift. At this point, however, it should be mentioned that the value of 180° is used here purely by way of example and for explanation.

[0062] Depending on the internal behavior and structure of the generally complex sensor device or of a corresponding sensor chip, different variants of an electrical loop, as explained above using examples, can be used to improve the measurement signal.

[0063] FIG. 5 schematically illustrates a sensor device 200″ according to the invention in a further preferred embodiment, likewise as a circuit diagram. The sensor device 200″ largely corresponds to the sensor device 200′, with the result that reference can be made to the statements there.

[0064] In contrast to the embodiment according to FIG. 4, however, the second electrical loop L.sub.2 is arranged directly downstream of the first electrical loop here and the capacitor C.sub.1 is—in addition to connection lines 237, 238 from the contact points 235, 236 to the capacitor C.sub.1—a constituent part of the second electrical loop, wherein the phase angle of the voltage U.sub.ind,1 is also shifted here with respect to the voltage U.sub.ind,H. Impedances, like in FIG. 3, could also be provided here, if necessary or desired.

[0065] In other words, the capacitor C.sub.1 shown in FIG. 4 is missing in the embodiment according to FIG. 5 and the capacitor C.sub.2 there instead undertakes its function. Therefore, the area of the first electrical loop L.sub.1 (comprising the sensor) should be delimited by the conductors, for example by bringing the conductors close together with a subsequent transition to the second electrical loop L.sub.2 which has the task of compensating for the induced voltage of the first area by means of the opposed rotational voltage. In this case, the second area of the second electrical loop need not be symmetrically divided between both conductors, but rather can also be implemented in various ways using only one conductor, for example, as also shown by way of example below.

[0066] The (single) capacitor C.sub.1 then has the task of the back-up capacitor for the supply voltage and has the task of the filter capacitor for the output voltage (depending on which conductor sections are a constituent part of the loop).

[0067] The induced rotational voltage in the area of the second loop L.sub.2 rotates or shifts the components through 180°. This means that any previous amplification of output interference can now result in attenuation, specifically on account of the 180° shift. However, it should be mentioned at this point that the value of 180° is used here purely by way of example and for explanation.

[0068] Depending on the internal behavior and structure of the generally complex sensor device or of a corresponding sensor chip, different variants of an electrical loop, as explained above using examples, can be used to improve the measurement signal.

[0069] Further examples of this type are schematically shown in FIGS. 6 to 11, wherein only a few of the components are denoted. In particular, possible ways of configuring the second electrical loop, and possibly a third electrical loop, also taking into account the positioning of the capacitor C.sub.1, are intended to be shown on the basis of the following exemplary embodiments. In this case, as in the preceding examples as well, the first electrical loop is formed between the two conductor sections 230, 231. As mentioned, it may also be formed between other conductor sections.

[0070] The second area of the second electrical loop L.sub.2 should expediently always be close to the sensor or Hall sensor 210 so that the magnetic field is large enough for this second area. The second area should be as large as the first area of the first electrical loop L.sub.1 if possible. However, there is also a positive effect even in the case of smaller areas. In this respect, FIG. 6 shows an example in which the second electrical loop is formed in such a manner that its (second) area is smaller than the (first) area of the first electrical loop L.sub.1. In this case, the second electrical loop is substantially formed by the connection line 237. In addition, the capacitor C.sub.1 is not a constituent part of the second electrical loop L.sub.2, which is insignificant for the functionality of both the second electrical loop L.sub.2 and the capacitor C.sub.1.

[0071] In the example in FIG. 7, the second electrical loop L.sub.2 is formed in such a manner that its (second) area corresponds approximately to the (first) area of the first electrical loop L.sub.1. In this case, the second electrical loop is substantially formed by the connection lines 237 and 238.

[0072] In the example in FIG. 8, the second electrical loop L.sub.2 is formed in such a manner that its (second) area corresponds approximately to the (first) area of the first electrical loop L.sub.1. In this case, the second electrical loop is substantially formed by the connection line 237.

[0073] In the example in FIG. 9, the second electrical loop L.sub.2 is formed in such a manner that its (second) area is smaller than the (first) area of the first electrical loop L.sub.1. In this case, the second electrical loop is substantially formed by the connection line 238. In this case, the connection line 238 is crossed in order to form the loop.

[0074] In the example in FIG. 10, a third electrical loop L.sub.3 is also provided in addition to the second electrical loop, wherein the second and third electrical loops are each formed in such a manner that their (second or third) area respectively corresponds approximately to half the (first) area of the first electrical loop L.sub.1. In this case, the second electrical loop is substantially formed by the connection line 237 and the third electrical loop is formed by the connection line 238. Like in the example in FIG. 9, each of the connection lines 237, 238 is crossed in order to form the respective loop.

[0075] In the example in FIG. 11, the second electrical loop L.sub.2 is formed in such a manner that its (second) area corresponds approximately to the (first) area of the first electrical loop L.sub.1. In this case, the second electrical loop is substantially formed by the connection line 237. In this case, the connection line 237 is crossed in order to form the loop.