Monitoring components for detecting faults in the feeder circuits of control devices

Abstract

The invention relates to a monitoring component (10) for identifying a feeder line fault of a control device (1), comprising: at least two mutually redundant current-carrying internal supply lines (LB1, LB2) arranged in the control device (1), which are electrically connected to external supply lines (L1_GND, L2_GND) at one end and to a common internal power supply potential level (C_GND) of the control device (1) at the other end; a signal detector (12), which inductively detects the current flowing through the respective internal supply line (LB1, LB2) and outputs at least one corresponding measurement signal; and an evaluation and control unit (16), which evaluates at least one measurement signal to identify a feeder line fault. The invention also relates to a method for identifying a feeder line fault of a control device (1), which is performed by the monitoring component (10). Here, two internal supply lines (LB1, LB2) each form a planar supply line coil (LG1, LG2) having at least one turn before an electrical connection point to a common internal power supply level (C_GND) of a control device (1), wherein a signal detector (12) has at least one planar sensor coil (LS1, LS2) for each planar supply line coil (LG1, LG2), which is respectively assigned to one of the supply line coils (LG1, LG2) and detects a high-frequency dynamic current caused by an internal switching process and passing through the corresponding planar supply line coil (LG1, LG2).

Description

Technical Field

[0001] The invention relates to a monitoring component for identifying a feeder line fault of a control device. The invention also relates to a method for identifying a feeder line fault of a control device. Background Art

[0002] Control devices, such as airbag control devices, are known from the prior art, which have a redundant ground supply. This redundancy also allows the control device to continue to operate without interference, even if one of the redundantly implemented grounding lines is no longer available due to defects such as cable breakage, oxidation of contacts in the connector, etc. This defect initially has no effect on the function of the control device itself, because at least one other grounding line is still available as a redundancy. However, in the ideal case, undetected (potential) faults should not occur or should occur rarely, especially in control devices with a high ASIL rating (ASIL: Automotive Safety Integrity Level). As a result, the following requirements are imposed on the maximum impedance of the individual grounding lines, that is, the ground potentials of the individual control devices should be prevented from differing too much from each other. The communication between the individual control devices is particularly susceptible to such deviations in the ground potential, also called "ground drift". In addition, there are EMC / ESD requirements that can only be met if the control devices are very well grounded. For redundantly implemented grounding lines, monitoring the increased impedance of one of the grounding lines (which may increase to the point of interruption) is a particular challenge. The required low impedance is still given by the redundant grounding line. For this reason, a normal resistance measurement between the ground potential of the vehicle power supply (usually the negative terminal of the vehicle battery) and the ground potential of the individual control devices fails here.

[0003] DE 10 2010 001 335 A1 discloses an electronic device with such a monitoring component for detecting a feeder line fault, the monitoring component comprising at least one redundant current-carrying feeder line located outside the device, which feeder line at least partially or completely supplies power to the device, wherein the redundant supply lines located outside are respectively electrically connected to internal conductors (e.g. conductor tracks) arranged in the device. The internal conductors extend adjacent to each other in a region, wherein in particular at least one magnetic field detector unit is arranged adjacent to the internal conductors between the internal conductors, with which a static and / or time-varying magnetic field can be measured. In the monitoring component there is a feeder line fault detection circuit, which obtains a fault signal from the signal obtained by the magnetic field detector unit, with which a fault in the power supply line can be determined. In the simplest case, the magnetic field detector unit is preferably a magnetic coil, which has a coil core made of a material with high magnetic permeability, in particular for increasing the signal strength. The coil core is made of a ferromagnetic material, for example. The number of windings of the electromagnetic coil is designed so that the highest possible measurement sensitivity is achieved with respect to the available installation space. The electromagnetic coil usually has a winding core, which is configured so that it can be compactly mounted on a printed circuit board. Thus, the coil can have, for example, a bobbin-shaped winding core, which has only a short cylindrical section. Summary of the invention

[0004] The monitoring component for detecting a fault in a feeder line of a control device and the method for detecting a fault in a feeder line of a control device with the features according to the invention each have the following advantages: By analyzing and evaluating the current distribution in the corresponding supply line, an increase in the impedance of one of the redundantly implemented supply lines can be detected. For this purpose, the high-frequency component of the return current of the control device on the redundant supply line is inductively transmitted to the evaluation and control unit. In order to improve the signal quality, a signal processor can be connected upstream of the evaluation and control circuit. The control device is powered by a DC voltage source, usually a battery. In the case of hybrid vehicles or pure electric vehicles, it is also conceivable to use a DC converter power supply unit to provide the necessary DC voltage. This current flows from the positive pole through the circuit of the control device back to the negative pole of the DC voltage source. Due to various switching processes in the control device, the current flowing out of the positive pole in the control device ECU is not constant. These switching processes in the control device can be triggered by the DC converter in the control device and by switching processes of computer units, sensors, actuators, etc. and by internal communication in the control device via a communication bus (SPI, address and data bus of a memory, etc.) and by external communication with other control devices via a vehicle bus system (e.g. CAN, FlexRay, Ethernet, etc.). This high-frequency dynamic current consumption of the control unit caused by internal switching processes is used in control units with redundant supply lines to detect supply line faults in order to locate the defective supply line with a significantly higher impedance.

[0005] An embodiment of the present invention provides a monitoring component for detecting a feeder line fault in a control device, comprising: at least two mutually redundant current-carrying internal supply lines arranged in the control device, which are connected to an external supply line at one end and to a common internal power supply potential level of the control device at the other end; a signal detector, which inductively detects the current flowing through the respective internal supply line and outputs at least one corresponding measurement signal; and an evaluation and control unit, which evaluates the at least one measurement signal for detecting a feeder line fault. In this case, the two internal supply lines each form a planar supply line coil with at least one turn before the electrical connection point to the common internal power supply potential level, wherein the signal detector has at least one planar sensor coil for each supply line coil, which is respectively assigned to one of the supply line coils and detects a high-frequency dynamic current caused by the internal switching process and flowing through the corresponding supply line coil.

[0006] Furthermore, a method for detecting a supply line fault in a control device is proposed, which can be performed with such a monitoring arrangement. In this case, the currents in at least two mutually redundant current-carrying internal supply lines are inductively detected in the control device, which are each connected to an external supply line at one end and to a common supply potential level at the other end, wherein the detected current signals are compared with one another and evaluated. In this case, the high-frequency dynamic currents caused by the internal switching process are detected as currents by at least one planar sensor coil respectively assigned to the respective planar supply line coil, which flow through at least two of the at least two planar supply line coils, which each form an internal supply line before the electrical connection point to the common internal supply potential level.

[0007] In the normal case where there is an equally good power supply connection in at least two redundant power supply lines, the supply current of the control device is evenly distributed on the redundant power supply lines that exist. The evaluation and control unit evaluates the difference between the redundant power supply lines. In the case where the current distribution in the redundant power supply lines is approximately the same, the difference is very small or close to zero. If the impedance on one of the redundant power supply lines increases significantly, for example due to a cable break, oxidation of contacts in the connector, etc., the current will now be asymmetrically distributed on the redundant power supply line or only flow through the remaining one or more power supply lines. The evaluation and control unit now determines the significant difference between the redundant power supply lines, and can provide the processed and filtered signals in analog or already digital form to the microcontroller or microprocessor or computing unit for further processing. In addition, the evaluation and control unit itself can be implemented as part of the microcontroller or microprocessor or computing unit. Then, the corresponding application or function on the computing unit can take further steps to provide driver information or store the error in an error memory.

[0008] In this article, evaluation and control unit can be understood as an electronic device for processing or evaluating detected sensor signals. The evaluation and control unit can have at least one interface based on hardware and / or software construction. In a hardware-based construction mode, the interface can be, for example, a part of the various functions of the evaluation and control unit of a so-called ASIC system. It is also feasible that the interface is a separate integrated circuit or is at least partially composed of discrete components. In a software-based construction mode, the interface can be, for example, a software module coexisting with other software modules on a microcontroller. It is also advantageous to have a computer program product with a program code, which is stored on a machine-readable carrier such as a semiconductor memory, a hard disk memory or an optical memory, and is used to perform evaluation when the program is run by the evaluation and control unit.

[0009] In this context, a supply line is understood to be a ground line or a voltage supply line which provides a corresponding voltage potential for the control device. Thus, for example, a redundant ground supply of a control device can be realized by at least two redundant ground lines. In the control device, corresponding redundant internal ground lines can be brought together at a common ground potential level. A redundant voltage supply can be realized accordingly by at least two redundant voltage supply lines. In the control device, corresponding redundant internal voltage supply lines can be brought together at a common voltage potential level.

[0010] The monitoring arrangement for detecting a feeder line fault of a control unit and the method for detecting a feeder line fault of a control unit described above can be advantageously improved by the measures and developments listed below.

[0011] It is particularly advantageous that at least two planar power supply line coils can be implemented identically. In addition, at least two planar sensor coils can be identically designed to have more turns than at least two power supply line coils. In order to minimize the impact on the common voltage potential level in the control device and the vehicle power supply line, the high-frequency dynamic current caused by the internal switching process, which is collected from all circuit components to the common power supply potential level, is now conducted to the redundant internal power supply line through the same planar power supply line coil. The planar power supply line coil has relatively few "turns" and the conductor track is wider in order to meet the current requirements of the control device. The high-frequency dynamic current caused by the internal switching process induces a smaller electromagnetic field in the planar power supply line coil. This electromagnetic field can now be picked up by one or more planar sensor coils and fed to the evaluation and control unit. The planar sensor coil usually includes more "turns" with narrower conductor tracks than the planar power supply line coil, so that each planar sensor coil is more sensitive to the smaller induced electromagnetic field. Depending on the available space on the printed circuit board, the planar power supply line coil or the planar sensor coil can have various shapes such as round, oval, square, rectangular, symmetrical polygonal and asymmetrical polygonal. For all angular variants, a change in direction of the conductor track can be made in a chamfered or rounded conductor track routing.

[0012] In an advantageous embodiment of the monitoring component, at least two planar supply line coils can be arranged in a first circuit board layer of a multilayer circuit board, and the at least one assigned planar sensor coil can be arranged in a second circuit board layer above or below the first circuit board layer. Thus, at least two planar supply line coils can be arranged side by side in the same first circuit board layer, for example, and the planar sensor coils assigned to the planar supply line coils can be arranged side by side in a second circuit board layer located above or below the first circuit board layer. This means that the circuit board is preferably implemented as a multilayer printed circuit board (PCB). Alternatively, the planar sensor coils and the planar supply line coils can be arranged in different circuit board layers, respectively. This means that, for example, two planar supply line coils and two assigned sensor coils are arranged as a stack in four circuit board layers.

[0013] In another advantageous embodiment of the monitoring assembly, the at least one assigned planar sensor coil can at least partially, preferably completely, cover the corresponding planar supply line coil. The planar sensor coil is ideally located in an overlapping manner above or between the planar supply line coils in another circuit board layer in order to maximize the coupling coefficient between the planar supply line coils and the planar sensor coils.

[0014] In another advantageous design of the monitoring assembly, a signal processor can form a loop between the signal detector and the evaluation and control unit, which can process at least one detected measurement signal. The signal quality can thus be improved before the evaluation. The signal processor can, for example, comprise a rectifier and / or a filter and / or an amplifier. The voltage induced in the planar sensor coil can be processed in terms of signal technology by the signal processor. Thus, the still small measurement signal can be amplified after optional rectification and filtering. Here, a multi-stage operational amplifier or a low-noise instrument amplifier can be used as an amplifier. The measurement signal processed in this way can now be fed to an analog-to-digital converter for more complex evaluation and further processed in a computer unit. Alternatively, a comparator circuit can be used for a simple evaluation.

[0015] In an advantageous embodiment of the method for detecting a feeder line fault in a control device, the absence of a feeder line fault is detected if the current distributions in at least two supply line coils are identical within a predefined tolerance range, otherwise a feeder line fault is detected. Furthermore, different accuracy levels can be preset for the detected feeder line faults by means of different tolerance ranges. Depending on the topology used and the arrangement of the planar supply line coils in the internal supply path, the number or arrangement of the planar sensor coils, the winding directions of the planar supply line coils relative to each other and to the planar sensor coils, and the complexity of the evaluation and control unit, different levels and accuracy levels of feeder line fault detection can be achieved, from simple to complex.

[0016] In simple line fault detection, it is possible to detect that the impedance of one of the redundant power supply lines has increased significantly without having to determine which of the power supply lines is involved. In addition, no judgment can be made about the quality of the remaining power supply lines. In more complex line fault detection, it is possible to determine which of the redundant power supply lines has increased impedance. In addition, the redundant power supply lines can be divided into different fault levels. Thus, if the impedance difference is within a narrow tolerance range, the redundant power supply line can be classified as fault-free. In the case of a slight increase in the impedance difference and within a wider but still acceptable tolerance range, the fault can be stored internally, but the driver information will not be output. The internally stored fault can then be read out via the diagnostic interface during the next visit to the repair shop. If the impedance difference increases significantly, that is, exceeds the still acceptable tolerance range, the fault can be stored internally and the corresponding driver information can be output, for example, via a warning light or a multi-function display. If the power supply line is interrupted and there is a maximum impedance difference, the fault can be stored internally and the corresponding driver information can be output, for example, via a warning light or a multi-function display. As a result, scaling and optimization according to customer requirements can be achieved in terms of circuit board area, the number of components used in the evaluation and control unit, and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Embodiments of the present invention are shown in the drawings and explained in more detail in the following description.In the drawings, the same reference numerals represent components or elements that perform the same or similar functions.

[0018] Figure 1 A schematic diagram of a control unit is shown, which has an exemplary embodiment of a monitoring arrangement according to the invention for detecting a feeder line fault of a control unit.

[0019] Figure 2 Shown for Figure 1 FIG. 1 is a schematic top view of a first embodiment of a signal detector of a monitoring assembly according to the present invention, without showing a multilayer printed circuit board in which the signal detector is arranged.

[0020] Figure 3 Shown for Figure 2 A schematic perspective view of a planar supply line coil and a planar sensor coil of a signal detector in FIG. 1 and a schematic cross-sectional view of a corresponding multilayer printed circuit board in which the signal detector is arranged.

[0021] Figure 4 A schematic perspective view of a planar supply line coil and a planar sensor coil for a second exemplary embodiment of a signal detector and a schematic cross-sectional view of a corresponding multilayer printed circuit board in which the signal detector is arranged are shown.

[0022] Figure 5 A schematic flow chart of an embodiment of a method for detecting a feeder line fault of a control device according to the present invention is shown. DETAILED DESCRIPTION

[0023] from Figures 1 to 4As can be seen, the illustrated embodiments of the monitoring assembly 10 according to the invention for detecting a feeder line fault of a control device 1 respectively comprise: at least two mutually redundant current-carrying internal supply lines LB1, LB2 arranged in the control device 1, which are electrically connected at one end to the external supply lines L1_GND, L2_GND respectively and at the other end to the common internal supply potential level C_GND of the control device 1 respectively; a signal detector 12, which inductively detects the current flowing through the internal supply lines LB1, LB2 and outputs at least one corresponding measurement signal; and an evaluation and control unit 16, which evaluates at least one measurement signal for detecting a feeder line fault. In this case, the two internal supply lines LB1, LB2 respectively form a planar supply line coil LG1, LG2 with at least one turn before the electrical connection point to the common internal supply potential level C_GND of the control device 1. The signal detector 12 has at least one planar sensor coil LS1, LS2 for each planar power supply line coil LG1, LG2, which is respectively assigned to one of the power supply line coils LG1, LG2 and detects a high-frequency dynamic current caused by internal switching processes and flowing through the corresponding power supply line coil LG1, LG2.

[0024] from Figure 1 It can also be seen that in the illustrated embodiment, the control device 1 includes a redundant grounded power supply having two mutually redundant current-carrying internal power supply lines LB1, LB2 arranged within the control device 1, which are connected at one end to the external power supply lines L1_GND, L2_GND, respectively. In addition, another power supply line not shown in detail provides the control device 1 with the onboard power supply voltage VB of the corresponding vehicle. In addition, in the illustrated embodiment, the control device 1 includes a DC voltage converter 5, which generates different internal voltages for the computing unit 7 and the communication unit 3 of the control device 1 from the onboard power supply voltage VB. In the illustrated embodiment, the computing unit 7 has an analog-to-digital converter 7.1, which converts the analog measurement signal of the monitoring circuit 10 into a digital signal. In addition, the computing unit 7 assumes the function of the evaluation and control unit 16 of the monitoring component 10 and evaluates the measurement signal to identify a feeder line fault. From Figure 1 It can also be seen that the monitoring assembly 10 shown includes a signal processor 14, which forms a loop between the signal detector 12 and the evaluation and control unit 16 and processes the detected at least one measurement signal. To this end, in the embodiment shown, the signal processor 14 includes a rectifier 14.1, a filter 14.2 and an amplifier 14.3. The signal processor 14 receives the two detected current signals and forms a difference signal as a measurement signal, which is further evaluated and classified by the downstream evaluation and control unit 16.

[0025] Especially from Figures 2 to 4It can be seen that the at least two planar supply line coils LG1 , LG2 are designed identically. The at least two planar sensor coils LS1 , LS2 are also identical, but have a greater number of turns than the at least two supply line coils LG1 , LG2 .

[0026] In the exemplary embodiment shown, the monitoring arrangement 10 comprises two internal supply lines LB1, LB2, which each form a planar supply line coil LG1, LG2. In this case, a planar sensor coil LS1, LS2 is respectively assigned to the planar supply line coil LG1, LG2.

[0027] from Figure 2 and Figure 3 It can also be seen that in the first embodiment of the signal detector 12A shown, two planar supply line coils LG1, LG2 are respectively arranged in the third circuit board layer S3 of the multilayer circuit board 20, which in the shown embodiment is implemented as a multilayer printed circuit board 20A with six circuit board layers S1 to S6. The two planar sensor coils LS1, LS2 assigned to the supply line coils LG1, LG2 are respectively arranged in the fourth circuit board layer S4 below the third circuit board layer S3. In the shown embodiment, other signals in the corresponding conductor tracks are transmitted in the first circuit board layer S1 and the sixth circuit board layer S6. Other signals different from the coil signals are also transmitted in the corresponding conductor tracks in the third circuit board layer S3 and the fourth circuit board layer S4. A common voltage potential level C_GND is provided in the second circuit board layer S2, which is the common ground level of the control device 1. The planar supply line coils LG1, LG2 are electrically connected to the common voltage potential level C_GND in the second circuit board layer S2 via through holes (not shown in detail). A common return path for the two planar sensor coils LS1 and LS2 is provided in the fifth circuit board layer S5 and is connected to the signal processor 14. The respective ends of the planar sensor coils LS1 and LS2 are electrically connected to the return path in the fifth circuit board layer S5 through corresponding plated through holes or through common through holes. The other ends of the planar sensor coils LS1 and LS2 are electrically connected to the signal processor 14 through corresponding conductor tracks. In addition, other signals can also be transmitted through the corresponding conductor tracks in the circuit board layer S5. Figure 2 and Figure 3 It can also be seen that the planar sensor coils LS1 , LS2 are arranged in such a way that they each completely cover the corresponding planar supply line coil LG1 , LG2 .

[0028] from Figure 4It can also be seen that in the second embodiment of the signal detector 12B shown, the planar sensor coils LS1, LS2 and the planar supply line coils LG1, LG2 are respectively arranged in different circuit board layers S4, S5, S6, S7 of the multilayer circuit board 20B, which in the shown embodiment is implemented as a multilayer printed circuit board 20B having ten circuit board layers S1 to S10. Of course, other embodiments of the multilayer circuit board 20 can also be used, which have more or less than six or ten circuit board layers.

[0029] from Figure 4 It can also be seen that in the second embodiment of the signal detector 12B shown, the first planar supply line coil LG1 is arranged in the fourth circuit board layer S4. Here, the first planar sensor coil LS1 assigned to the first supply line coil LG1 is arranged in the fifth circuit board layer S5 below the first supply line coil LG1 in the fourth circuit board layer S4. In the second embodiment of the signal detector 12B shown, the second planar supply line coil LG2 is arranged in the seventh circuit board layer S7. Here, the second planar sensor coil LS2 assigned to the second supply line coil LG2 is arranged in the sixth circuit board layer S6 above the second planar supply line coil LG2 in the seventh circuit board layer S7. Thus, in the second embodiment of the signal detector 12B shown, the two planar sensor coils LS1, LS2 are arranged between the two planar supply line coils LG1, LG2. In the embodiment shown, other signals in the corresponding conductor tracks are transmitted in the first circuit board layer S1, the second circuit board layer S2, the ninth circuit board layer S9 and the tenth circuit board layer S10. Other signals different from the coil signal are also transmitted in the corresponding conductor tracks in the fourth circuit board layer S4 to the seventh circuit board layer S7. A common voltage potential level C_GND is provided in the third circuit board layer S3, which is the common ground level of the control device 1. The planar power supply line coils LG1 and LG2 are electrically connected to the common voltage potential level C_GND in the third circuit board layer S3 via through holes (not shown in detail). A common return path for two planar sensor coils LS1 and LS2 is arranged in the eighth circuit board layer S8 and is connected to the signal processor 14. The respective ends of the planar sensor coils LS1 and LS2 are electrically connected to the return path in the eighth circuit board layer S8 via corresponding plated through holes. The other ends of the planar sensor coils LS1 and LS2 are electrically connected to the signal processor 14 via corresponding conductor traces, respectively. In addition, other signals can also be transmitted via the corresponding conductor traces in the printed circuit board layer S8. From Figure 4 It can also be seen that the planar sensor coils LS1 , LS2 are arranged such that they completely cover the corresponding planar supply line coils LG1 , LG2 , respectively.

[0030] from Figure 5It can also be seen that in step S100, according to the illustrated embodiment of the method 100 for detecting a feeder line fault of a control device 1, the current is inductively detected in each of at least two mutually redundant current-carrying internal supply lines LB1, LB2 in the control device 1, which are connected to the external supply line L1_GND, L2_GND at one end and to the common supply potential level C_GND at the other end. In this case, the high-frequency dynamic current caused by the internal switching process is detected as a current by at least one planar sensor coil LS1, LS2 assigned to the respective planar supply line coil LG1, LG2, which flows through at least two internal supply lines LB1, LB2 of the at least two planar supply line coils LG1, LG2, which form the internal supply line LB1, LB2 before the electrical connection point to the common internal supply potential level C_GND. In step S110, the detected current signals are compared with each other and evaluated. For this purpose, a difference signal is formed from the detected current signals, and the difference signal is evaluated as a measurement signal. Thus, for example, if the current distribution in at least two supply line coils LG1, LG2 is identical or the determined current difference is within a preset tolerance range, then no feeder line fault is detected. Otherwise, a feeder line fault is detected. In the illustrated embodiment, an optional classification of the detected feeder line fault is performed in step S120. Thus, different accuracy levels are preset for the detected feeder line faults by means of different tolerance ranges. Depending on the topology used and the arrangement of the planar supply line coils LG1, LG2 in the internal supply path, the number or arrangement of the planar sensor coils LS1, LS2, the winding direction of the planar supply line coils LG1, LG2 relative to each other and to the planar sensor coils LS1, LS2, and the complexity of the evaluation and control unit 16, different levels and accuracy levels of feeder line fault detection can be realized, from simple to complex.

Claims

1. A monitoring component (10) for identifying a feeder line fault of a control device (1), comprising: At least two mutually redundant current-carrying internal power supply lines (LB1, LB2) arranged in the control device (1), the internal power supply lines being electrically connected at one end to the external power supply lines (L1_GND, L2_GND) respectively and at the other end to a common internal power supply potential level (C_GND) of the control device (1); a signal detector (12) which inductively detects a current flowing through each of the internal power supply lines (LB1, LB2) and outputs at least one corresponding measurement signal; and an evaluation and control unit (16) which evaluates the at least one measurement signal in the form of a difference signal of the current signal in order to detect a feeder line fault, It is characterized in that At least two of the internal power supply lines (LB1, LB2) each form a planar power supply line coil (LG1, LG2) having at least one turn before the electrical connection point with the common internal power supply potential level (C_GND), The signal detector (12) has at least one planar sensor coil (LS1, LS2) for each planar power supply line coil (LG1, LG2), the planar sensor coil being respectively assigned to one of the power supply line coils (LG1, LG2) and detecting a high-frequency dynamic current flowing through the corresponding power supply line coil (LG1, LG2) caused by an internal switching process, At least two planar power supply line coils (LG1, LG2) are respectively arranged in a first circuit board layer of a multilayer circuit board (20), and at least one associated planar sensor coil (LS1, LS2) is arranged in a second circuit board layer above or below the first circuit board layer.

2. The monitoring component (10) according to claim 1, characterized in that The at least two planar power supply line coils (LG1, LG2) are designed identically, wherein the at least two planar sensor coils (LS1, LS2) are designed identically with a greater number of turns than the at least two planar power supply line coils (LG1, LG2).

3. The monitoring component (10) according to claim 1 or 2, characterized in that: The planar sensor coils (LS1, LS2) and the planar supply line coils (LG1, LG2) are respectively arranged in different circuit board layers.

4. The monitoring component (10) according to claim 1, characterized in that The at least one associated planar sensor coil (LS1, LS2) at least partially covers the corresponding planar supply line coil (LG1, LG2).

5. The monitoring component (10) according to claim 1, characterized in that The at least one associated planar sensor coil (LS1, LS2) completely covers the corresponding planar supply line coil (LG1, LG2).

6. The monitoring component (10) according to claim 1 or 2, characterized in that: A signal processor (14) forms a loop between the signal detector (12) and the evaluation and control unit (16) and processes the at least one detected measurement signal.

7. The monitoring component (10) according to claim 6, characterized in that The signal processor (14) comprises a rectifier (14.1) and / or a filter (14.2) and / or an amplifier (14.3).

8. A method (100) for identifying a feeder line fault of a control device (1), wherein the control device (1) comprises a monitoring component (10) according to any one of claims 1 to 7 for carrying out the method, wherein the currents in at least two mutually redundant current-carrying internal power supply lines (LB1, LB2) are respectively detected inductively in the control device (1), wherein the internal power supply lines (LB1, LB2) are connected at one end to an external power supply line (L1_GND, L2_GND) and at the other end to a common supply potential level (C_GND), wherein the detected current signals are compared with each other and evaluated, It is characterized in that High-frequency dynamic currents caused by internal switching processes are detected as currents by at least one planar sensor coil (LS1, LS2) respectively assigned to the corresponding planar supply line coil (LG1, LG2), which flow through at least two internal supply lines (LB1, LB2) of at least two planar supply line coils (LG1, LG2), which respectively form the internal supply lines (LB1, LB2) before an electrical connection point to a common internal power supply potential level (C_GND).

9. The method (100) according to claim 8, characterized in that: If the current distributions in the at least two planar power supply line coils (LG1, LG2) are identical within a predefined tolerance range, then no feeder line fault is detected, otherwise a feeder line fault is detected.

10. The method (100) according to claim 9, characterized in that: Different tolerance ranges are used to predetermine different accuracy levels for detected feeder line faults.

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