Monitoring device and method for an on-board power system of an at least partially electrically driven motor vehicle

Abstract

The invention relates to a monitoring device (14) for an on-board power system (12) of an at least partially electrically operated motor vehicle (10), having a switching device (16) designed to switch a high-voltage positive path (18) and a high-voltage negative path (20) of an energy store (22) of the on-board power system (12), wherein the switching device (16) has a control line (24, 24a, 24b, 24c) coupled to an explosive safety mechanism (26), wherein the switching device (16) opens the high-voltage positive path (18) and the high-voltage negative path (20) when the control line (24, 24a, 24b, 24c) is broken, wherein a control line switch device (28) is connected in the control line (24, 24a, 24b, 24c) in series with the explosive safety mechanism (26), wherein the control line switch device (28) opens the control line (24, 24a, 24b, 24c) in dependence on a control signal (30) of an electronic computing device (32) of the monitoring device (14). The invention also relates to a method.

Description

Technical Field

[0001] This invention relates to a monitoring device for an onboard electrical network of a motor vehicle, at least partially electric, according to the preamble of claim 1. The invention also relates to a method. Background Technology

[0002] In the high-voltage on-board electrical system of at least partially electric motor vehicles (also known as hybrid vehicles), especially in the case of fully electric vehicles, it is necessary to safely and quickly disconnect the power supply in the event of an accident. For this purpose, power supply components, especially storage devices and batteries, have specific control lines also known as terminal 30C (KL30C). Power is supplied through this cable, particularly to the main contactor of the storage device, so that any disconnection, such as that occurring during maintenance or as a circuit break caused by triggering a fuse ignited by the airbag controller, inevitably leads to the shutdown of the on-board electrical system, especially the high-voltage components. Once the voltage at KL30C drops, other components, such as drive inverters or potentially fuel cells, also have hardware and / or software-side preventative measures to activate safety-related procedures.

[0003] If a connection to other parallel power lines is now established due to a fault (such as cable wear), reliable shutdown is no longer guaranteed in the event of a collision or maintenance, as the contactor can still be powered via the cable terminals, which will also prevent other safety responses.

[0004] Another common practice is to transmit signals to all contactors and other components within the system via a single KL30C safety circuit. However, this is particularly disadvantageous in maintenance situations, where it may be desirable to close contactors, especially those that could potentially separate a local power grid from the main power grid, without the risk of unintended power connection, which would mean that voltages exceeding, for example, the 60-volt DC safety threshold might occur within the system.

[0005] DE 10 2009 036 672 A1 discloses a circuit-breaking procedure for a high-voltage system in a motor vehicle. To this end, a switching device is provided, comprising a first switch for disconnecting a first terminal from a second terminal and a second switch for disconnecting a third terminal from a fourth terminal. Furthermore, the switching device includes an operating element for triggering the first switch. A delay device is provided for automatically triggering the second switch after a predetermined time following the triggering of the first switch. Summary of the Invention

[0006] The objective of this invention is to provide a monitoring device and a method thereby enabling the safe operation of the onboard electrical network for at least partially electric motor vehicles.

[0007] This task is accomplished by the monitoring device and method according to the independent claim. Advantageous embodiments are described in the dependent claims.

[0008] One aspect of the invention relates to a monitoring device for an onboard electrical system of at least partially electric motor vehicles, having a switching device designed to switch the high-voltage positive path and high-voltage negative path of an energy storage device in the onboard electrical system, wherein the switching device has a control line connected to an explosive / explosive / pyrotechnic safety mechanism, wherein, in the event of disconnection of the control line, the switching device disconnects the high-voltage positive path and the high-voltage negative path. Such a switching device may, for example, be a high-voltage battery contactor, which can be disconnected as needed via the control line of so-called terminal 30C, thereby disconnecting the high-voltage battery from the onboard electrical system and the system.

[0009] It is stipulated that a control line switch device shall be connected in series with the explosion safety mechanism to the control line, wherein the control line switch device can disconnect the control line according to the control signal of the electronic computing device of the monitoring device.

[0010] Specifically, it is stipulated that the so-called relay, as a control line switching device, is connected in series with the explosion-proof safety mechanism. This safety line is also specifically referred to as the KL30C line. The relay is controlled by a controller, i.e., an electronic computing device. This also allows for checking the potential within the KL30C line, for example, before voltage is applied, i.e., especially within the so-called on-board electrical system startup procedure. If there is voltage on the KL30C line with the relay already open, this can be identified from the components connected to the KL30C line. Because all components or controllers are connected via corresponding bus components, especially CAN bus components, the check result can be transmitted to the central controller and compared with the target value there. If the result is incorrect, the battery is prevented from connecting to the on-board electrical system. If there is no voltage on the line with the relay open, the relay is closed and the user is supplied with the corresponding voltage on the control line and a positive check is performed. If the desired voltage is then present at the KL30C input terminals of all relevant components, the system is functioning normally and the battery startup can proceed without danger.

[0011] In other words, it is proposed that, in addition to the explosion-proof safety mechanism, which can also be referred to as an explosive fuse, a control line switch device is connected in series on the terminal 30C for safely disconnecting the voltage connection, so as to better guarantee and extend the safety conditions. For this purpose, the control line switch device can be advantageously arranged in series upstream of the explosion-proof safety mechanism so as to simultaneously allow for the inspection of this control line area.

[0012] The relay, connected in series upstream as a control line switch, can therefore disconnect in the event of a fault in the control line area prior to the exploding fuse. Additionally, the relay can also disconnect the voltage in the control line even in the event of a collision where the airbag is not triggered (in which case the exploding fuse would normally disconnect the control line).

[0013] Furthermore, other states of motor vehicles can be considered, in which reversible disconnection of the control line and consequently disconnection of the high-voltage components may be meaningful and can be achieved using the present invention, without resorting to irreversible disconnection by means of explosive fuses due to safety concerns.

[0014] It is particularly proposed to connect the relay in series with the explosive fuse, which thus serves as another safety trigger in the event of a failure of the explosive fuse itself, and / or can be controlled separately to disconnect the voltage in the control line and thus switch the high-voltage components to no voltage via downstream switching devices.

[0015] According to an advantageous embodiment, the electronic computing device is designed to check the voltage potential in the control line via a control line switching device before connecting the battery to the vehicle's electrical grid.

[0016] Another advantage is that when another switching device is disconnected, the actual voltage in the control line, as evaluated by an electronic computing device, is compared with the target voltage, and a control signal is generated based on the comparison result.

[0017] It also proves advantageous that the control line has a maintenance interface, which is designed to disconnect the control line upon operation. This is also commonly referred to as "maintenance disconnection" because by manually operating the maintenance interface, especially when working on motor vehicles within the factory, the high-voltage components can be safely switched to de-energized status by disconnecting the control line, thus enabling safe operation of the motor vehicle.

[0018] In another advantageous embodiment, the monitoring device has another safety mechanism within the control line, wherein this other safety mechanism is connected to at least one power auxiliary output device. This other safety mechanism advantageously includes a diode for preventing power from being fed back from the power auxiliary output device to the control line. Therefore, it is necessary to prevent voltage feedback from the power auxiliary output device to the control line, which could cause the control line to malfunction.

[0019] Another safety mechanism can also advantageously include a fuse for short-circuit protection of the control lines. This prevents the entire vehicle electrical network from having to be forcibly disconnected due to a short circuit in the auxiliary power output device.

[0020] Another aspect of the invention relates to an onboard electrical grid having a monitoring device according to a prior aspect. Yet another aspect of the invention relates to a motor vehicle having an onboard electrical grid.

[0021] Another aspect of the invention relates to a method for operating a monitoring device for an onboard electrical network of a motor vehicle that is at least partially electric, wherein a high-voltage positive path and a high-voltage negative path of an energy storage device of the onboard electrical network are switched by means of a switching device, wherein the switching device has a control line connected to an explosion safety mechanism, wherein the switching device is disconnected when the control line is disconnected, and the high-voltage positive path and the high-voltage negative path are disconnected.

[0022] It is stipulated that a control line switch device shall be connected in series with the explosion safety mechanism within the control line, wherein the control line shall be disconnected by means of the control line switch device based on the control signal of the electronic computing device of the monitoring device.

[0023] Advantageous embodiments of the monitoring device should be considered advantageous embodiments of the on-board electrical network, the motor vehicle, and the method. The monitoring device, the on-board electrical network, and the motor vehicle therefore possess the subject matter characteristics that allow the execution of the method or its advantageous embodiments. Attached Figure Description

[0024] Other advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and in conjunction with the drawings. The features and combinations thereof mentioned above in the specification, as well as those mentioned below in the description of the drawings and / or shown individually in the unique drawings, may be used not only in their respective specified combinations, but also in other combinations or individually, without departing from the scope of the invention.

[0025] Here, the only illustration is a schematic block diagram of a motor vehicle embodiment having an on-board electrical grid embodiment with a monitoring device. Detailed Implementation

[0026] In the figure, identical or functionally identical parts are labeled with the same reference numerals.

[0027] The only illustration is a schematic block diagram showing an embodiment of the motor vehicle 10. The motor vehicle 10 is shown here purely schematically. The motor vehicle 10 is at least partially electric. In particular, the motor vehicle 10 is fully electric. The motor vehicle 10 has an on-board electrical network 12. The on-board electrical network 12 has, in particular, a monitoring device 14. The monitoring device 14 has a switching device 16, which is designed to switch the high-voltage positive path 18 and the high-voltage negative path 20 of the battery 22 of the on-board electrical network 12. The switching device 16 has control lines 24, 24a, 24b, 24c connected to the explosion-proof safety mechanism 26. When the control lines 24, 24a, 24b, 24c are disconnected, the switching device 16 disconnects the high-voltage positive path 18 and the high-voltage negative path 20.

[0028] Control lines 24, 24a, 24b, and 24c, which can also be referred to as KL30C lines, are described in particular. To better describe control line 24, different areas of control line 24a, 24b, and 24c are labeled with their own reference numerals, but they always involve the common control line. Therefore, control lines 24, 24a, 24b, and 24c are generally referred to as control lines 24 below.

[0029] It is specified that a control line switch device 28 is connected in series with the explosion safety mechanism 26 within the control line 24, wherein the control line switch device 28 can disconnect the control line 24 based on the control signal 30 of the electronic computing device 32 of the monitoring device 14. In particular, the control line switch device 28 is designed as a relay. If the control line 24 is disconnected via the control line switch device 28, the control line regions 24a, 24b, and 24c downstream of the control line switch device 28 are switched to de-voltage without causing a malfunction.

[0030] Hereinafter, control line 24 will always be described in relation to power-on or power-off control. However, in this case, current naturally flows when the connection is made; the current is not negligible and should not be ignored, and its magnitude can also depend on the switching devices 16, 38a, and 46 to be switched. Corresponding to the switching devices connected to control line 24 that are to be controlled and switched, the current in this case should of course also have a minimum intensity, but this is clear and known to those skilled in the art regarding control. Therefore, this aspect is not described in detail below, and the corresponding size and dimensions are specified here according to the system design.

[0031] In this case, "no voltage in the control line" also means that the voltage in the control line is so low that it is impossible to switch or close the switching devices 16, 38a, and 46, and therefore the voltage threshold required for switching is not exceeded.

[0032] The explosive safety mechanism 26 may be triggered, for example, by an airbag controller or other controller (not shown), to quickly and safely disconnect the vehicle electrical network 12 or at least a portion of the vehicle electrical network in the event of a hazardous situation or malfunction. This explosive safety mechanism 26 is also referred to as an explosive fuse and indicates the irreversible disconnection of the control line 24.

[0033] In this case, the control line switch device 28 is designed as a reversible switch device, thereby always being able to electrically connect and disconnect the control line 24. For this purpose, in the illustrated embodiment, the control line switch device 28 is arranged in series before / upstream of the explosion safety mechanism 26, so that the control line region 24a between the control line switch device 28 and the explosion safety mechanism 26 can be switched to voltage-free mode by the control line switch device 28 instead of the explosion safety mechanism 26. In this case, the control line region 24a can also be monitored by the monitoring device 14. The control line region 24b after / downstream of the explosion safety mechanism 26 can then be switched to voltage-free mode not only reversibly by the control line switch device 28 but also irreversibly by the explosion safety mechanism 26.

[0034] Specifically, it can be specified that the electronic computing device 32 is designed to check the voltage potential in the control line 24 according to the function of the control line switch device 28 before connecting the battery 22 to the vehicle power grid 12. Accordingly, it can be specified that the actual voltage in the control line 24 evaluated by the electronic computing device 32 with the control line switch device 28 being open is compared with the target voltage, and a control signal 30 is generated or the connection of the battery 22 is prevented based on the comparison result.

[0035] The figure also shows that the control line 24 has a maintenance interface 34, also referred to as a maintenance disconnect device, wherein the maintenance interface 34 is designed to disconnect the control line 24 upon operation. Therefore, the disconnection of the control line 24 is achieved, especially by manually operating the maintenance interface 34 when working on the vehicle 10 in the factory, thereby safely switching the high-voltage component 48 to de-voltage and thus enabling safe operation of the vehicle 10.

[0036] By operating the maintenance interface 34, the control line 24 is disconnected such that control line region 24c is de-energized, and thus the switching device 16 disconnects the high-voltage positive path 18 and the high-voltage negative path 20. Therefore, with the maintenance interface 34 operated, control line region 24c is de-energized, and thus the contactor of the accumulator 22 is disconnected, which also switches the high-voltage component 48 to de-energized. Other switching devices connected to and thus controlled by control line region 24c are also disconnected when the maintenance interface 34 is operated, thereby disconnecting the connected regions and / or components.

[0037] Other components of the vehicle electrical network 12 that are connected to the control line area 24b and whose switching devices and / or contactors are controlled through the control line area 24b, especially the local electrical network or charging sockets, are not affected by the disconnection through the maintenance interface 34.

[0038] In this configuration, the maintenance interface 34, in the illustrated embodiment, is arranged in series within the control line region 24b, downstream of the explosion-proof safety mechanism 26. Thus, the control line region 24b is unaffected by the maintenance interface 34, and only the control line region 24c can be switched to voltage-free mode. Correspondingly, the control line switching device 28 switches the control line region 24c to voltage-free mode in a reversible manner, while the explosion-proof safety mechanism 26 switches it to voltage-free mode along with the control line region 24b in an irreversible manner.

[0039] In an alternative implementation, in the event of no voltage or undervoltage in the control line 24 or in the control line areas 24a, 24b, 24c, the connected switching device can still be closed instead of opened, depending on the function and application of the vehicle electrical network 12 area or corresponding component switched by the switching device.

[0040] Furthermore, the figure shows that the monitoring device 14 may have another safety mechanism 36 in the control line area 24b, wherein the other safety mechanism 36 is connected to at least one power auxiliary output device 38, which may also be referred to as an electric auxiliary output device (ePTO). An electric auxiliary output device refers to another user that is not necessarily part of the actual on-board electrical network 12 of the motor vehicle 10 and may only be connected to it.

[0041] The term "electric auxiliary output device" is also used for "electric auxiliary output mechanism" (ePTO), which typically functions to drive additional components by being connected to the power supply device of the motor vehicle 10, similar to the mechanical output device of the motor vehicle drive system.

[0042] The connection between control line area 24b, specifically another safety mechanism 36, and the auxiliary output device switch 38a of the power auxiliary output device 38, still allows the power auxiliary output device 38 to be controlled and correspondingly connected and disconnected with the rest of the vehicle's electrical network via the auxiliary output device switch 38a and, consequently, via control line 24. Other power-consuming users, such as vehicle body components like cooling structures, lifting mechanisms, garbage compactors, and hydraulic pumps, can be connected to this power auxiliary output mechanism.

[0043] In this embodiment, safety mechanism 36 includes a diode 40 and a fuse 42, which should not only limit the current flow within control line 24b but also prevent energy backflow. In particular, diode 40 can be designed as a replacement for or supplement to fuse 42.

[0044] To prevent potential malfunctions in the externally manufactured vehicle body, particularly in the power auxiliary output device 38, or to prevent undesirable feedback or power supply to the KL30C vehicle system in the event of a malfunction, thus ensuring at least continued operation, an additional diode 40 and / or fuse 42 may be installed in this branch of the KL30C power grid. In this case, the diode 40 serves as a feedback protection mechanism and the additional fuse 42 serves as a short-circuit protection mechanism, preventing the entire vehicle electrical grid 12 from being forcibly disconnected from the vehicle body due to a short circuit, as described above.

[0045] It is also shown that the battery 22 can be connected to other users 44 of the vehicle 10 via high-voltage positive path 18 and high-voltage negative path 20. Other users 44 are shown only schematically. Users 44 connected to high-voltage paths 18 and 20 may also be collectively referred to as high-voltage components 48, and include, for example, high-voltage inverters or DC / AC converters, DC / DC converters, high-voltage charging systems, high-voltage auxiliary heaters, or other components powered or connected to the high voltage of the vehicle electrical network 12, in addition to the battery of the battery 22.

[0046] Therefore, it is proposed to add a control line switch device 28, which can also be called a relay, to the control line 24. This relay can be specifically referred to as a KL30C relay, and can be controlled by an electronic computing device 32, which can also be designed as a central computing device. This allows the potential of the KL30C line to be checked before voltage is applied, particularly during the “start-up procedure” of the battery 22. If voltage is present on the KL30C line, specifically in control line areas 24a, 24b, and 24c when the relay is open, it can be identified from the components connected to the KL30C line. Because all components or controllers are connected via a CAN bus, the check result can be transmitted to the electronic computing device 32 and compared with a target value there. If the result is incorrect, it indicates a fault in the control line 24, particularly in control line areas 24a, 24b, and 24c, and prevents the battery 22 from being turned on. If there is no voltage on the control line 24 when the relay is open, the relay is closed and a positive check is performed. If the desired voltage is present at the KL30C input terminals of all relevant components, the on-board electrical grid 12 is functioning normally and the start-up and operation of the battery 22 can proceed without danger. Accordingly, the control line 24 prevents the switching device, especially the switching device 16, from being disconnected, so the user 44 can be supplied with electrical energy from the battery 22 accordingly.

[0047] Furthermore, the control line switch device 28 can also be used to reversibly disconnect the vehicle electrical network 12 in the event of a minor collision in which the explosive safety mechanism 26 is not triggered by the airbag controller. A corresponding signal can be used for this purpose. Alternatively, when an unavoidable accident is detected (e.g., through an auxiliary system that generates a corresponding pre-collision recognition signal), the KL30C relay can be disconnected shortly before the collision, particularly shortly before the cold deformation of the vehicle 10, thus prompting the system to reach a safe state earlier than known from the prior art.

[0048] To address the aforementioned necessity of local power grid interconnection while ensuring maximum safety by maintaining power disconnection, a branch is provided in control line 24 between the explosion-proof safety mechanism 26 and the maintenance interface 34, i.e., in control line area 24b. Components that are not powered or lack power, such as charging sockets and especially their contactors, can be connected to this branch. This allows certain contactors, such as the charging contactor, to continue operating even when the vehicle power grid 12 or high-voltage component 48 is disconnected for system fault diagnosis, during maintenance where the maintenance disconnect device performs an on / off locking function. All other components connected to KL30C in control line area 24c reliably remain disconnected when the maintenance disconnect device is de-energized. Furthermore, by monitoring the voltage of control line 24, and especially by comparing the voltage between control line areas 24b and 24c, it can be immediately identified whether the maintenance disconnect device is still operating when the ignition is on, and an alarm may be displayed on the vehicle 10's display device.

[0049] This invention generally demonstrates the generation of secure line monitoring.

[0050] List of reference numerals

[0051] 10 Motor vehicles

[0052] 12 Vehicle-mounted power grid

[0053] 14 Monitoring devices

[0054] 16 Switching devices

[0055] 18 High-voltage positive path

[0056] 20 High-voltage negative path

[0057] 22 Storage devices

[0058] 24 control lines

[0059] 24a Control Line Area

[0060] 24b control line area

[0061] 24c control line area

[0062] 26 Explosion-proof safety mechanisms

[0063] 28. Control line switch device

[0064] 30 Control Signals

[0065] 32 Electronic computing devices

[0066] 34 Maintenance Interface

[0067] 36 Other security agencies

[0068] 38. Power Auxiliary Output Device

[0069] 38a Auxiliary output device switching device

[0070] 40 diode

[0071] 42. Insurance

[0072] 44 users

[0073] 46 Another switching device

[0074] 48 High-voltage components

Claims

1. A monitoring device (14) for an onboard electrical network (12) of a motor vehicle (10) that is at least partially electric, the monitoring device having a switching device (16) designed to switch the high-voltage positive path (18) and the high-voltage negative path (20) of an energy storage device (22) of the onboard electrical network (12), in, The switching device (16) has control lines (24, 24a, 24b, 24c) connected to the explosion safety mechanism (26), wherein, when the control lines (24, 24a, 24b, 24c) are disconnected, the switching device (16) disconnects the high-voltage positive path (18) and the high-voltage negative path (20), and A control line switch device (28) is connected in series with the explosion safety mechanism (26) in the control line (24). The control line switch device (28) disconnects the control lines (24, 24a, 24b, 24c) based on the control signal (30) from the electronic computing device (32) of the monitoring device (14). Its characteristics are, The electronic computing device (32) is designed to check the voltage potential in the control lines (24, 24a, 24b, 24c) via the control line switch device (28) before connecting the battery (22) to the vehicle electrical network (12). The actual voltage evaluated by the electronic computing device (32) in the control lines (24, 24a, 24b, 24c) when the control line switch device (28) is disconnected is compared with the target voltage, and the control signal (30) is generated based on the comparison result.

2. The monitoring device (14) according to claim 1, characterized in that, The control lines (24, 24a, 24b, 24c) have a maintenance interface (34) which is designed to disconnect the control lines (24, 24a, 24b, 24c) based on operation.

3. The monitoring device (14) according to claim 1 or 2, characterized in that, The monitoring device (14) has another safety mechanism (36) within the control line (24b), wherein the other safety mechanism (36) is connected to at least one power auxiliary output device (38).

4. The monitoring device (14) according to claim 3, characterized in that, The other safety mechanism (36) has a diode (40) for preventing power from being fed back from the power auxiliary output device (38) to the control line (24b).

5. The monitoring device (14) according to claim 3, characterized in that, The other security unit (36) has a safety device (42) for protecting the control line (24b).

6. A method for operating a monitoring device (14) for an onboard electrical network (12) of a motor vehicle (10) that is at least partially electric, wherein, A switching device (16) is used to switch the high-voltage positive path (18) and high-voltage negative path (20) of the battery (22) of the vehicle-mounted electrical network (12). The switching device (16) has control lines (24, 24a, 24b, 24c) connected to an explosive safety mechanism (26). When the control lines (24, 24a, 24b, 24c) are disconnected, the high-voltage positive path (18) and the high-voltage negative path (20) are disconnected by the switching device (16). A control line switching device (28) is connected in series with the explosive safety mechanism (26) in the control lines (24, 24a, 24b, 24c). 24c) The control line switch (28) is disconnected according to the control signal (30) of the electronic computing device (32) of the monitoring device (14), characterized in that the electronic computing device (32) is designed to check the voltage potential in the control line (24, 24a, 24b, 24c) by means of the control line switch (28) before connecting the battery (22) to the vehicle electrical network (12). The actual voltage evaluated by the electronic computing device (32) in the control lines (24, 24a, 24b, 24c) when the control line switch device (28) is disconnected is compared with the target voltage, and the control signal (30) is generated based on the comparison result.

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