ELECTRONIC DEVICE WITH CURVE SENSOR INTEGRATED INTO A HEAT SURFACE

Description

[0001] The invention relates to an electronic device comprising at least one component to be cooled, a cooling element for cooling the component to be cooled, at least one power line, and a respective current sensor for detecting the current intensity of a current flowing through the respective power line. The cooling element has a recess into which the current sensor engages or in which the current sensor is arranged. The invention also relates to a motor vehicle.

[0002] In many applications, it is necessary to monitor the currents supplied to an electronic device or the currents provided by it. For example, traction inverters in motor vehicles typically require monitoring and control of the power or current supplied. AC sensors can be used for this purpose. Hall sensors, for example, can be used as AC sensors. To achieve high sensitivity with the simplest possible wiring, open-loop Hall sensors can be used. These sensors feature a flux concentrator, for example, a soft iron ring wrapped around the cable. With an open-loop sensor, the Hall voltage is measured directly.

[0003] The problem here is that corresponding Hall sensors are relatively large. Furthermore, the components of the Hall sensor can heat up during operation, which can potentially lead to measurement errors or reduce measurement accuracy.

[0004] From the publication DE 10 2004 054 317 A1, a current measuring device is known in which the current flows through a current channel arranged to surround a predetermined point on a substrate. A magnetic measuring element is provided at this point to convert the magnetic flux into a voltage. The current channel is applied in layers on a highly thermally conductive substrate, on the back of which a heat-dissipating heat sink is arranged. A disadvantage of this approach is that a relatively large installation space is still required for current measurement. Furthermore, it is not possible to use standard components for current measurement, which ultimately results in higher costs and greater complexity for the electronic device.

[0005] Document DE 10 2015 111 204 A1 discloses a power electronics module with load connection elements. A circuit carrier and a base plate have recesses that are aligned with one another, with a load connection element being guided through these recesses. The base plate can be a cooling device. A current sensor can be arranged partially or completely in an extension of the base plate recess.

[0006] The subsequently published document EP 3 236 724 A1 discloses a power electronics arrangement. A current sensor is arranged in a recess of a liquid cooling device.

[0007] Document DE 10 2015 202 770 A1 relates to a device for integrated current measurement within a high-voltage contact of a hybrid module. The current sensors are molded into a plastic housing of the high-voltage contact connector. Similar arrangements of current sensors are also known from documents US 2008 / 0048642 A1 and US 2006 / 0255793 A1.

[0008] From the document WO 94 / 27157 A1 a current measuring device is known in which the yokes of different current measuring devices are accommodated in separate recesses of a housing part.

[0009] The document EP 2 261 973 A2 describes a power electronic system with a housing, a cooling device and a power converter circuit.

[0010] The invention is therefore based on the object of providing a space-saving possibility for measuring a current in an electronic device, which can be implemented in particular with low technical complexity.

[0011] The object is achieved according to the invention by an electronic device of the type mentioned at the outset, wherein several of the current sensors are arranged together in the recess of the cooling element.

[0012] According to the invention, it is therefore proposed to at least partially integrate a current sensor into a cooling element already provided in the electronic device. By at least partially accommodating the current sensor in the cooling element, installation space can be saved. At the same time, this results in cooling of the current sensor, which potentially allows the size of the current sensor to be further reduced and / or its measurement sensitivity to be increased.

[0013] The cooling element can, for example, be a cooling plate, which can be used to cool electrical semiconductor switches or other heat-generating components of the electronic device. The cooling plate can, for example, be a metal plate, which, due to its high thermal conductivity, increases the surface area for heat dissipation. However, it is also possible for the cooling element or cooling plate to comprise active cooling. For example, the cooling element or cooling plate can be interspersed with cooling channels through which a cooling fluid flows.

[0014] The current sensor can be designed as a prefabricated module that is attached to the cooling plate, in particular via a current sensor housing. The current sensor can be screwed, riveted, latched, or glued to the cooling element. The current sensor can, in particular, be an alternating current sensor. For example, a Hall sensor with a flux concentrator can be used. The current sensor can, in particular, provide a voltage that depends on the measured current. This can be detected by a control device, in particular with the aid of an analog-to-digital converter.

[0015] The electronic device can be an electronic module that has at least one defined connection for connecting to other components. The components of the electronic module can, in particular, be arranged within a housing. The recess of the cooling element can, in particular, be an opening.

[0016] The power line can supply power to the electronic device, or it can be used to supply power from the electronic device to another component. For example, if the electronic device is a current transformer, the current of one or more output lines can be measured. Alternatively or additionally, it is also possible for the power line to connect several components of the electronic device.

[0017] Preferably, the power line is routed through a recess in the current sensor. Current measurement can, in particular, be contactless. The recess can be surrounded at least partially by a flux concentrator of the current sensor, for example, by an open soft iron ring. The recess can, in particular, extend through a housing of the current sensor. The power line can terminate at least on one side with an open contact area, which serves to connect a connecting means. For example, the power line can terminate in a plug or a socket.

[0018] The recess of the cooling element can be an opening through which the current line is passed. In particular, the current sensor can be arranged in the opening and the current line can be passed through the current sensor. By passing the current line through the opening, cooling of the current line can be achieved, particularly in the area of ​​the current sensor. This can make it possible to use a current line that has a smaller cross-section, at least in the area of ​​the current sensor, than would be required for an uncooled line. When using a smaller cross-section, however, a flux concentrator with a smaller inner diameter can be used at the same time, thereby making it possible to realize a smaller current sensor overall.

[0019] According to the invention, several current sensors are arranged together in the recess of the cooling element. The current sensors can, in particular, be arranged in a common housing. This allows for a simpler construction of the electronic device. If several current sensors are arranged together in an opening, with the power lines each routed through the current sensors, a connecting element, for example a plug or socket, for all power lines can be formed, in particular through contact areas of the power lines on one side of the cooling element. This allows for a simple connection of several power lines.

[0020] A housing containing one or more current sensors can be shaped such that it is guided or held by the recess of the cooling element. If the recess is an opening, the housing can have a support section that protrudes beyond the opening, so that after insertion into the opening, the housing rests with the support section on the cooling element. This allows for particularly simple installation of the current sensor(s). The support section can have a recess or opening, for example, to guide a screw or rivet with which the current sensor is attached to the cooling element.

[0021] The current sensor can have a flux concentrating element that surrounds the power line and has an opening in the circumferential direction in which a Hall probe is arranged. The flux concentrating element can, for example, have an open ring shape or a C-shape. Hall probes with flux concentrators are known in principle in the prior art and will not be explained in detail. With a Hall probe, at least in open-loop measurements, a fixed current is applied to the Hall probe, and a voltage drop essentially perpendicular to this current is measured. Since there is a clear relationship between the induced field and a conducted current, a voltage drop across a Hall probe, and a field permeating the Hall probe, a current in the power line can thus be measured without contact. The relationship between a voltage drop across the Hall probe and the current can be assumed to be approximately linear.However, it is also possible to measure this relationship beforehand and, for example, to store it as a table of values ​​in a control device that records the measurement data from the Hall sensor.

[0022] The flux concentration element can be made of soft iron or another paramagnetic or soft-magnetic material, for example. The flux concentration element and / or the Hall probe can be located at least partially, preferably completely, within the recess of the cooling element. By cooling the Hall probe and / or the flux concentration element, the sensitivity of the Hall probe can be improved, and a smaller overall current sensor can be realized.

[0023] The electronic device can be a power converter or comprise a power converter. It can, in particular, be an inverter, particularly for an electric motor, for example, a drive motor of a motor vehicle.

[0024] The component to be cooled, or at least one of the components to be cooled, can be a semiconductor switch. The semiconductor switch can be a transistor, for example an IGBT or a MOSFET. Circuits for converting currents using semiconductor switches are known in the art and will therefore not be explained here. Compared to relays, for example, semiconductor switches allow significantly shorter switching intervals. Semiconductor switches can now be realized that have very low resistance when the switch is closed. Nevertheless, a certain amount of power is lost at the semiconductor switch, particularly in the case of high currents in one direction, as required, for example, for drive motors, which typically cools corresponding circuits. A cooling element required for this purpose can be used in the electronic device according to the invention simultaneously to accommodate and cool the current sensor.

[0025] The cooling element can be made of metal, at least in the area of ​​the recess. A cooling element made of metal, in particular a cooling plate, has good thermal conductivity and can thus serve to increase the surface area over which heat can be dissipated. As already explained, it can be advantageous to additionally provide active cooling, for example, whereby cooling fluid can be guided through cooling channels of the cooling element. Constructing the cooling element from metal, at least in some areas, improves the electromagnetic shielding of the current sensor against external influences. This can serve to further increase measurement accuracy. Alternatively or additionally, a smaller current sensor can also be realized due to the improved electromagnetic shielding.

[0026] In addition to the electronic device according to the invention, the invention relates to a motor vehicle comprising an electronic device according to the invention. The electronic device can be used in particular as an inverter for an engine of the motor vehicle, specifically a drive motor of the motor vehicle.

[0027] Preferably, the motor vehicle comprises a control device that regulates the power supplied to the motor. At least one of the current sensors detects a current supplied to the motor, and a sensor signal from this sensor can be used as an input variable for a power control system. The control system can regulate the current to a desired value, for example, by pulse-width control of the semiconductor switches used in the reverse direction.

[0028] Further advantages and details of the invention will become apparent from the following exemplary embodiments and the accompanying drawings. These schematically show: Fig. 1 shows an embodiment of an electronic device according to the invention, Figs. 2 and 3 show detailed views of a further embodiment of an electronic device according to the invention, and Fig. 4 shows an embodiment of a motor vehicle according to the invention.

[0029] Fig. 1 shows an electronic device 1 with several components 2 to be cooled, which are arranged on a printed circuit board 3 and are cooled by a cooling device 4. In the example shown, the electronic device 1 is an inverter that converts a direct current provided by a battery 5 and supplies an alternating current to a motor 6. The motor 6 can, for example, be a drive motor of a motor vehicle. The alternating current is supplied via a power line 7. For a clearer illustration, Fig. 1 only one power line 7 is shown. However, as will be explained later, several power lines 7 can preferably be used to supply current to the motor 6 in order to provide a three-phase current to the motor 6.

[0030] The components 2 to be cooled can, in particular, be semiconductor switches used to convert the current. For this purpose, appropriate switching signals or pulse widths and phase positions can be specified by a control device 8. The cooling element 4 can be a cooling plate, which can be designed, for example, as a metal plate. Optionally, cooling channels could be provided in the cooling element 4, through which a cooling fluid can be passed to further improve the cooling of the component 2 to be cooled.

[0031] In order to regulate the current supplied via the power line 7 to a desired value, an actual current value is to be determined by the control device 8. For this purpose, the electronic device 1 has a current sensor 9, which is arranged in a recess 10, namely an opening, in the cooling element 4. The structure of the current sensor 9 will be described in more detail later with reference to Fig. 2 and 3The current sensor 9 is formed by a flux concentrator that surrounds the power line 7 and has an opening in which a Hall probe is arranged. If a fixed current is conducted via two contacts with such a Hall probe, a voltage can be tapped via two additional contacts that is approximately proportional to the current flowing through the power line 7. Nonlinearities of this sensor can be compensated for by a prior calibration, for which purpose, for example, a look-up table can be stored in the controller 8.

[0032] The power cable 7 is guided through a recess 11, namely an opening, of the current sensor 9 in order to enable a contactless measurement of the current.

[0033] The illustrated design of the electronic device 1 enables the integration of a current measurement with minimal installation space by arranging the current sensor 9 in the cooling device 4. Furthermore, since both the current sensor 9 and the power line 7 in the area of ​​the current sensor 9 are cooled by the cooling element 4, the measurement accuracy of the current sensor 9 can be improved and the cross-section of the power line 7 can be reduced, thus also enabling the use of a more compact current sensor 9.

[0034] Fig. 2 and 3 show detailed views of another embodiment of an electronic device. The structure essentially corresponds to that shown in Fig. 1 shown device, wherein instead of one power line 7, three power lines 7 are used to provide three phases of alternating current to an external device, for example the motor 6. Already with reference to Fig. 1 Elements discussed are designated by the same reference numerals.

[0035] Three current sensors 9 for the three power lines 7 are arranged in the recess 10 of the cooling element 4. These are attached to the cooling element 4 via a common housing 12. The housing 12 can be Fig. 2 be inserted into the recess 10 from above and rests on the edge of the recess 10 with support sections 13. These have openings in order to fasten the housing 10 and thus the current sensors 9 to the cooling element 4 with fastening elements 14, for example with screws.

[0036] The individual current sensors 9 are formed by a flux concentration element 15 surrounding the current line 7 and a Hall probe 16, wherein the flux concentration element 15 has an opening in the circumferential direction in which the Hall probe 16 is arranged. The wiring of the Hall probe 16 is not shown for reasons of clarity. The sections 17 of the current lines 7, in which they traverse the cooling element 4 and the current sensor 9, have a narrowed cross-section. This is made possible by the fact that the current line 7 is cooled in this area 17 by the cooling element 4, thereby improving the current-carrying capacity. This also allows the recess 11 of the current sensor 9 or the flux concentration element 15 to have a smaller diameter than would otherwise be necessary, whereby the current sensor 9 can be constructed more compactly overall.

[0037] The power lines 7 have contacts 19 that are open on one side, forming a connector 18 in the area of ​​the cooling element. The motor 6, for example, can be connected to this connector via a corresponding connector.

[0038] If the cooling element 4 is formed of metal at least in the region of the recess 10, the cooling element 4 can simultaneously serve for electromagnetic shielding of the current sensor 9, whereby its measuring accuracy can be improved.

[0039] Fig. 4 shows a motor vehicle 20 having an electronic drive motor as the motor 6, which is powered by the battery 5, for example a high-voltage battery. In order to convert the direct current provided by the battery 5 into a three-phase alternating current, an electronic device 1 is provided, which, as shown in Fig. 1 explained, where as with reference to Fig. 2 and 3As explained above, separate power lines 7 are used for the individual phases of the alternating current. The control device 8 acquires data from a plurality of vehicle devices 21, for example from an accelerator pedal sensor, in order to specify a target power for the motor 6. In order to set this target power, the control device 8, on the one hand, acquires the currently supplied current via the current sensors 9 of the electronic device 1 and, on the other hand, specifies pulse widths for the semiconductor switches of the electronic device in order to regulate the actually supplied current to the target current.

Claims

1. Electronic apparatus with at least one component (2) to be cooled, a cooling element (4) for cooling the component (2) to be cooled, at least one power line (7) and a corresponding current sensor (9) for detecting a current intensity of a current flowing through the corresponding power line (7), wherein the cooling element (4) has a recess (10), in which the current sensor (9) engages or in which the current sensor (9) is arranged, characterised in that multiple of the current sensors (9) are arranged together in the recess (10) in the cooling element (4).

2. Electronic apparatus according to claim 1, characterised in that the power line (7) is guided through a recess (11) in the current sensor (9).

3. Electronic apparatus according to claim 1 or 2, characterised in that the recess (10) in the cooling element (4) is an opening though which the power line (7) is guided.

4. Electronic apparatus according to any one of the preceding claims characterised in that the current sensors (9) are arranged in a common housing (12).

5. Electronic apparatus according to any one of the preceding claims, characterised in that the current sensor (9) has a flow concentration element (15) surrounding the power line (7), which has an opening in the circumferential direction, in which a Hall probe (16) is arranged.

6. Electronic apparatus according to any one of the preceding claims, characterised in that it is a power converter or comprises a power converter.

7. Electronic apparatus according to claim 6, characterised in that the component (2) to be cooled or at least one of the components (2) to be cooled is a semiconductor switch.

8. Electronic apparatus according to any one of the preceding claims, characterised in that the cooling element (4) consists of metal, at least in the region of the recess (10).

9. Motor vehicle characterised in that it comprises an electronic apparatus (1) according to any one of the preceding claims.