Vehicle on-board electrical system and vehicle comprising such a vehicle on-board electrical system

Abstract

The invention relates to a vehicle on-board electrical system (12), comprising: an energy distribution unit (18); a first DC-DC converter (22) which can be connected to the energy distribution unit (18) and to a high-voltage battery (14) of the vehicle (10) and is designed to convert a high voltage provided by the high-voltage battery (14) into a first on-board electrical system low voltage; a second DC-DC converter (26) which can be connected to the high-voltage battery (14), is connected or can be connected to the energy distribution unit (18) and is designed to convert the high voltage provided by the high-voltage battery (14) into a second on-board electrical system low voltage, said second on-board electrical system low voltage lying in a range below the first on-board electrical system low voltage; and a control unit (28) which is connected to the energy distribution unit (18) and is designed to supply low-voltage loads (16) of the vehicle on-board electrical system (12) with the first on-board electrical system low voltage in a first vehicle state and to supply the low-voltage loads (16) only with the second on-board electrical system low voltage in a second vehicle state.

Description

[0001] Description

[0002] Vehicle electrical system and vehicle with such a vehicle electrical system

[0003] The present invention relates to a vehicle electrical system for a vehicle, in particular for an electric vehicle or for an electrically powered vehicle, and to a vehicle with such a vehicle electrical system.

[0004] Vehicles typically have an electrical system that supplies the vehicle's electrical components with energy / power. These components are usually low-voltage devices, operating on a low-voltage electrical system voltage ranging from 5V to 16V.

[0005] Supplying power to low-voltage consumers such as lights, turn signals, fans, control units, air conditioning, heating, etc., while a vehicle is in operation is not critical. In electric vehicles, for example, the energy for these low-voltage consumers can be drawn directly from the high-voltage battery. Electric vehicles typically have at least one DC-DC converter for this purpose, which converts the high-voltage voltage from the battery into the low-voltage electrical system voltage required for the low-voltage consumers. The energy or power is then usually distributed throughout the vehicle by a power distribution unit.

[0006] The situation is different when the vehicle is in park mode, for example. In park mode, it is best if all non-critical loads and low-voltage consumers are switched off, and only the critical loads (key-off loads) are supplied by the vehicle's electrical system. Critical low-voltage consumers include, for example, the immobilizer, alarm system, GPS tracker, cameras, access control, and the like.

[0007] The object of the present invention is therefore to provide a vehicle electrical system and a vehicle, in particular an electrically powered vehicle, with such a vehicle electrical system, which can ensure an energy-saving and simple supply of critical loads or critical low-voltage consumers, especially in parking mode.

[0008] This task is solved by the subject matter of the independent claims.

[0009] Further advantages of the invention are the subject of the dependent claims. According to one aspect of the present invention, a vehicle electrical system for an electrically powered vehicle or electric vehicle is provided, wherein the vehicle electrical system comprises: a power distribution unit for distributing electrical energy or electrical power within the vehicle electrical system; a first DC-DC converter, which is connectable to or is connected to the power distribution unit and to a high-voltage battery of the vehicle, wherein the first DC-DC converter is configured to convert a high-voltage voltage provided by the high-voltage battery of the vehicle into a first low-voltage electrical system voltage, which is in the range of 24V to 60V; a second DC-DC converter, which is connectable to or is connected to the high-voltage battery of the vehicle and to the power distribution unit.is connected, wherein the second DC-DC converter is configured to convert the high-voltage voltage provided by the high-voltage battery into a second low-voltage on-board voltage, which is in a range below the first low-voltage on-board voltage and in particular in a range of 5V to 16V; and a control unit, which is connected to the power distribution unit and is configured to provide, in a first vehicle state, in particular in ferry operation of the vehicle, the first low-voltage on-board voltage provided by the first DC-DC converter to low-voltage consumers such as indicators, tailgate, A / C, ECUs, steering, lights, fans of the vehicle on-board network, and in a second vehicle state, in particular in park operation of the vehicle, to provide only the second low-voltage on-board voltage provided by the second DC-DC converter to the low-voltage consumers.

[0010] The present invention is based, at least in part, on the realization that supplying energy to key-off loads in parking mode is costly. Currently, separate batteries are used to ensure power supply in parking mode. These batteries are intended to provide the energy / power for critical low-voltage consumers during parking. However, it has been recognized that this additional battery can be eliminated. It has been recognized that, particularly in an electric vehicle, the traction battery or the high-voltage battery can be used to supply energy / power to critical loads even in parking mode, without requiring an additional battery in the vehicle's electrical system. It has been recognized that, especially in vehicle electrical systems with a low-voltage system voltage of 48V or higher, the use of an additional battery is uneconomical for various reasons, such as cost, weight, and installation space.The invention proposes providing an additional DC-DC converter instead of a separate battery. This additional DC-DC converter can also be referred to as a micro-DC-DC converter. This additional DC-DC converter takes over the function of the separate battery. The additional DC-DC converter (second DC-DC converter) is connected to, or can be connected to, the high-voltage battery and provides a low-voltage electrical system voltage sufficient to power the key-off loads. A control unit detects whether the vehicle is in a first vehicle state, which may be, in particular, the vehicle being driven, or in a second vehicle state, which may be, in particular, the vehicle being parked. If the vehicle is in the first vehicle state, the control unit ensures that the low-voltage consumers are supplied with the (first) low-voltage electrical system voltage as usual.However, when the vehicle is in the second vehicle state, the low-voltage consumers and especially the key-off loads of the vehicle electrical system are only supplied by the power provided by the micro-DCDC converter.

[0011] Preferably, the second DC-DC converter is connected to the power distributor via a diode, and the second DC-DC converter provides the second low-voltage on-board voltage in both the first and second vehicle states, whereby the diode is designed such that in the first vehicle state, the first low-voltage on-board voltage provided by the first DC-DC converter is not present at the second DC-DC converter, or no current can flow into the second DC-DC converter.

[0012] Another preferred embodiment provides that the second DC-DC converter is designed for a maximum power output of 15 watts, preferably a maximum of 10 watts, and even more preferably a maximum of 5 watts. This preferred embodiment is based on the understanding that the second DC-DC converter needs to provide significantly less power than the first DC-DC converter, which is typically used, particularly because it only has to supply the key-off loads. The micro-DC-DC converter requires less installation space, is easier to control, and is more cost-effective. The micro-DC-DC converter therefore represents a genuine alternative to the separate batteries used to date. Another preferred embodiment provides that the first DC-DC converter is designed for a power output of at least 1000 watts. In other words, the first DC-DC converter is the one typically used to supply (all) low-voltage loads.Naturally, a modern vehicle architecture can have several, especially two, of these DC-DC converters, for example for redundancy reasons, as is necessary for autonomous or assisted ferry operation. However, the second DC-DC converter would also typically be designed for a power requirement of at least 1000 watts, since this second DC-DC converter would also have to supply all low-voltage consumers with power.

[0013] In vehicles with a zonal electrical system architecture, each low-voltage consumer can be connected to a converter, for example, a converter located in a zone control unit or zone controller of the vehicle's electrical system. This converter typically comprises a half-bridge with a high-side transistor circuit and a low-side transistor circuit. This converter, which is usually already present in zonal electrical system architectures, can selectively provide either the first or the second low-voltage electrical system voltage to supply the low-voltage consumers.The preferred embodiment now provides that the control unit is controllably connected to such converters in such a way that, in the first vehicle state, i.e., the vehicle state in which the low-voltage consumers are supplied with the first low-voltage on-board voltage, the high-side transistor circuit and the low-side transistor circuit are controlled in such a way that the low-voltage consumers can only be supplied with the first low-voltage on-board voltage, and that, in the second vehicle state, i.e., the vehicle state in which the low-voltage consumers are to be supplied with the second low-voltage on-board voltage (namely from the micro-DCDC), the low-side transistor circuit is opened and the high-side transistor circuit is closed, so that the low-voltage consumers can only be supplied with the second low-voltage on-board voltage.

[0014] In other words, the design envisages that in the first vehicle state, the (zone) converters operate as usual as (buck) DC-DC converters, i.e., converting a 48V vehicle electrical system voltage to 12V or 5V, and that in the second vehicle state, the (zone) converters are operated not as converters but as "pass-through" converters, by opening the low-side transistor circuit and closing the high-side transistor circuit. While the (zone) converters typically have an inductor that exhibits a certain inductance when current flows through it, this inductance has little or no effect because the inductor is supplied with a constant voltage / power. In other words, the loss through the (converter) inductor is negligible in the second vehicle state. The preferred embodiment therefore provides for the (zone) converters to be used not as converters but as (pass-through) switches in the second vehicle state.This allows the (zone) converter to be used in both the first and second low-voltage on-board voltage ranges.

[0015] Another preferred embodiment provides that the power distribution unit typically includes a switching device that acts as an electrical safety device (such as an eFuse), wherein the switching device typically has a first switching state (e.g., "off" or "closed") and a second switching state (e.g., "on" or "open"), and wherein the first switching state is typically assumed in the first vehicle state and the second switching state is typically assumed in the second vehicle state (as a safety function). The preferred embodiment provides that the control unit is configured such that the first switching state of the switching device is set in the first vehicle state, and the second switching state of the switching device is set in the second vehicle state.In other words, the preferred embodiment provides that the eFuse, which is normally inactive in the first vehicle state, remains in the first switching state, whereas the eFuse, which is normally active in the second vehicle state, is actively switched from the second switching state to the first switching state. The preferred embodiment is based on the understanding that an eFuse, such as those commonly used as a safety device in power distribution units, can be actively deactivated by the control unit, or actively switched from the second (open) switching state to the first (closed) switching state, when the vehicle is in the second vehicle state and key-off loads still need to be supplied with power.

[0016] It is further preferred that the second DC-DC converter is connected to the high-voltage battery in such a way that it provides the second low-voltage electrical system voltage in both the first and second vehicle states. In other words, the micro-DC-DC converter is always active and always provides the second low-voltage electrical system voltage, both in the first and second vehicle states (even though it would not be needed in the first state). The low power consumption of the micro-DC-DC converter allows for continuous operation without significant losses.

[0017] It is further preferred that the first DC-DC converter is connected to the high-voltage battery in such a way that it is only supplied with high voltage in the first vehicle state. In other words, the first DC-DC converter is only active in the first vehicle state and is switched off in the second vehicle state (parking mode). This avoids the comparatively high power consumption of the first DC-DC converter, at least in the second vehicle state.

[0018] Another aspect of the present invention provides for a vehicle that has such a vehicle electrical system. The vehicle is in particular an electric vehicle, wherein a high-voltage battery of the electric vehicle is used to supply the electrical power to the first and second DC-DC converters.

[0019] Further features and functions of the present invention will become apparent to the person skilled in the art by carrying out the teaching presented here and by examining the accompanying drawings. These show:

[0020] FIG 1 shows a schematic view of an embodiment of a vehicle electrical system according to the invention,

[0021] FIG 2 shows a schematic view of another embodiment of a vehicle electrical system according to the invention,

[0022] FIG 3 shows a schematic view of a possible control of a half-bridge, where the half-bridge is operated as a converter, and

[0023] FIG 4 shows a schematic view of another possible control of the half-bridge of FIG 3. Elements of the same construction or function are provided with the same reference numerals across figures.

[0024] Reference is first made to FIG. 1, which shows a schematic view of a vehicle 10 with a vehicle electrical system 12. In the specific example of FIG. 1, the vehicle 10 is an electric vehicle or an electrically powered vehicle with a high-voltage battery or traction battery 14, wherein the high-voltage battery can provide a high-voltage voltage in a range of more than 60V, preferably at least 400V, and more preferably at least 800V.

[0025] The vehicle electrical system 12 has several low-voltage consumers 16, which can also be referred to as low-voltage loads or simply loads.

[0026] Low-voltage consumers 16 are required in the vehicle's electrical system 12 to ensure various functions and / or operations, as is well known to experts. Examples of low-voltage consumers 16 include: immobilizer, alarm system, GPS tracker, cameras, access control, turn signals, tailgate, A / C, ECUs, steering, lights, fans, etc.

[0027] To supply the low-voltage consumers 16 with energy / power, the vehicle electrical system 12 also includes a power distribution unit 18. This unit 18 typically serves to distribute energy / power within the vehicle electrical system 12. In the specific example shown in FIG. 1, the vehicle electrical system 12 also includes so-called zone controllers 32. The zone controllers 32 are connected to the power distribution unit 18 and, in turn, distribute the energy to the low-voltage consumers 16 connected to the respective zone controller 32. In other embodiments not shown, zone controllers 32 may not be present.

[0028] Particularly in electric vehicles, the low-voltage consumers 16 are powered from the high-voltage battery 14 during ferry operation of the vehicle 10. The vehicle's electrical system 12 typically includes a DC / DC converter (first DC / DC converter) 22 for this purpose, which converts the high-voltage voltage into a low-voltage electrical system voltage (first low-voltage electrical system voltage). This low-voltage electrical system voltage is usually in the range of 24 V to 48 V, but can also be in the range up to 60 V. The DC / DC converter 22 is connected to the high-voltage battery 14 and provides the low-voltage electrical system voltage required in the vehicle's electrical system 12. In the specific example shown in FIG. 1, two DC / DC converters 22 are shown, one of which is present for redundancy. In other examples not shown, only a single DC / DC converter 22 may be provided.

[0029] The first DC-DC converter(s) 22 are connected to a switching device 24 of the power distribution unit 18. The switching device 24 functions as a safety device and is, for example, an electronic fuse (eFuse). The switching device 24 can have a first switching state and a second switching state, and it can be switched between these two states. In the first switching state, an electrical connection is typically established between the first DC-DC converter 22 and the power distribution unit 18. In other words, in the first switching state, the low-voltage loads 16 can be supplied with electrical energy / power. In the second switching state, an electrical connection between the first DC-DC converter 22 and the power distribution unit 18 is typically interrupted. The second switching state can be understood as a safety shutdown in the sense of an eFuse functionality.For example, in park mode, not all low-voltage consumers 16 should be supplied with electrical power. The interruption of the supply to these low-voltage consumers 16 is ensured by the eFuse functionality.

[0030] In a ferry operation of vehicle 10, which is an example of a first vehicle state, the low-voltage consumers 16 are typically supplied with electrical power provided by the first DC-DC converters 22. In the first vehicle state, the switching device is therefore typically in the first (closed) switching state, so that the electrical connection between DC-DC converter 22 and low-voltage consumers 16 exists.

[0031] However, if the vehicle is in a parking mode, which is an example of a second vehicle state, the switching device 24 typically switches to the second (open) switching state according to its eFuse functionality. In this state, the low-voltage consumers 16 would not be supplied with electrical power.

[0032] For safety and other reasons, it is necessary that some low-voltage consumers, such as immobilizers, alarm systems, GPS trackers, cameras, access controllers, etc., continue to receive power even in parked mode. These so-called key-off loads must be supplied with power.

[0033] Until now, these key-off loads were powered by a separate battery.

[0034] The present invention proposes a different approach.

[0035] As shown in FIG. 1, the vehicle electrical system 12 has an additional, second DC-DC converter 26 for this purpose. The second DC-DC converter 26 can be connected to, or is connected to, the high-voltage battery 14 and converts the high-voltage voltage of the high-voltage battery 14 into a second low-voltage electrical system voltage, which is in a range below the first low-voltage electrical system voltage, and in particular in a range of 5 V to 16 V, preferably 12 V. The second low-voltage electrical system voltage is suitable for supplying energy / power to the critical low-voltage consumers 16.

[0036] The second DC-DC converter 26, unlike the first DC-DC converter 22, is designed only for key-off loads. For example, the second DC-DC converter 26 is designed for a maximum power output of 15 watts, preferably a maximum of 10 watts, and more preferably a maximum of 5 watts. In contrast, the first DC-DC converter 22 is typically designed for power outputs of at least 1000 watts, since, unlike the second DC-DC converter 26, it must be able to supply energy not only to key-off loads but also to all low-voltage consumers 16 of the vehicle electrical system 12. The second DC-DC converter 26 has a simpler design, is easier to control, is less expensive, lighter, and requires less installation space than the first DC-DC converter 22. The second DC-DC converter 26 can also be referred to as a micro-DC-DC converter.The second DC voltage converter 26 can be connected to the high-voltage battery 14, so that it always provides power, i.e., in both the first and second vehicle states; the losses generated thereby are negligible.

[0037] The vehicle electrical system 12 also includes a control unit 28, which is connected, among other things, to the power distribution unit 18. The control unit 28 is designed such that, in the first vehicle state, the low-voltage consumers 16 are supplied with the first low-voltage electrical system voltage or power, and in the second vehicle state, the low-voltage consumers 16 are supplied only with the second low-voltage electrical system voltage or power.

[0038] If, for example, it has been determined that the first vehicle state exists, the switching device 24 will typically be in the first (closed) switching state and the low-voltage consumers 16 will be supplied with the power provided by the first DC-DC converter 22. In such a case, the control unit 28 will not change the switching state of the switching device 24.

[0039] However, if, for example, it is determined that the second vehicle state exists because the vehicle 10 is in park mode, the switching device 24 will typically be in the second (open) switching state, and the low-voltage consumers 16 will typically not be supplied with power. In such a case, however, the control unit 28 will control the switching device 24 in such a way that the switching device 24 changes from the second (open) state to the first (closed) state. The low-voltage consumers 16 can then be supplied with power, specifically with the power provided by the second DC-DC converter (micro-DC-DC) 26. The first DC-DC converter(s) 22 are typically inactive in the second vehicle state and can remain inactive, because the necessary power for the key-off loads is provided by the micro-DC-DC 26.A separate battery, usually provided for the second vehicle state, can be omitted.

[0040] The control unit 28 can be a separate control unit or it can be a functional unit within a control unit already existing in the vehicle architecture. For example, a typical vehicle electrical system architecture usually has a master controller, which is schematically indicated by reference numeral 30 in FIG. 1. It is conceivable that the control unit 28 could be integrated into the master controller 30. Other configurations of the control unit 28 are, of course, also possible.

[0041] As already indicated, modern vehicle electrical system architectures may exhibit zonal structures. As an example, FIG. 1 shows various zone control units 32. These control units, also referred to as zone controllers, supply power to several low-voltage consumers 16. These zone control units 32 are connected to the power distribution unit 18 and may, for example, themselves include further converters 33, such as DC-DC converters. These converters 33 convert the vehicle electrical system voltage provided by the power distribution unit 18 into the low-voltage voltage relevant / necessary for the low-voltage consumers 16. If, for example, a typical low-voltage vehicle electrical system voltage 10 is 48 V, then the converters 33 of the zone control units 32 would convert this 48 V into, for example, 16 V, 12 V, or 5 V, depending on the voltages for which the low-voltage consumers 16 are designed.

[0042] Another aspect of the present invention is therefore to use these converters 33 by means of clever control of the control unit 28 in such a way that the low-voltage consumers 16 can be supplied with electrical power in both the first and second vehicle states. One possibility of control is explained in FIGS. 3 and 4.

[0043] First, however, reference is made to FIG 2, which shows a further embodiment of the vehicle electrical system 12 or of the vehicle 10 according to the invention.

[0044] In contrast to the embodiment according to FIG. 1, the embodiment according to FIG. 2 includes a blocking diode 34 between the output of the second DC-DC converter 26 and the input of the power distribution unit 18 or the switching device 24. The blocking diode 34 prevents electrical power or current from flowing into the second DC-DC converter 26 in the first vehicle state and with the first DC-DC converter 22 active. In other words, the diode 34 blocks the electrical path towards the second DC-DC converter 26.

[0045] Figures 3 and 4 now show schematic parts of the previously mentioned converter 33.

[0046] The converter 33 typically comprises a half-bridge 36 with a high-side transistor circuit 38 and a low-side transistor circuit 40. An inductor 42 is arranged between the transistor circuits 38 and 40, as is well known to those skilled in the art of such converters.

[0047] As shown in FIG. 3, in the first vehicle state, the converter 33 operates as usual, i.e., as a converter that transforms a low-voltage on-board voltage Vin into a low-voltage on-board voltage Vout. FIG. 3 shows the typical case of the first vehicle state, in which the initial low-voltage on-board voltage Vin is 48V in this example. The converter 33 would convert this voltage into the voltage Vout required for the low-voltage consumers, which is 12V in this example.

[0048] In the second vehicle state, e.g., in park mode, the control unit would control the converter 33 differently. An example is shown in FIG. 4. The control unit would, for example, control the converter 33 or the half-bridge 36 such that the low-side transistor circuit 40 is open or interrupted, and the high-side transistor circuit 38 is closed. In such a case, the converter 33 would not be used as a converter, but as a switch, so that the second low-voltage on-board voltage provided by the micro-DC-DC converter in the second vehicle state can be supplied directly (i.e., without conversion) to the low-voltage consumers. The control unit essentially repurposes the existing converter 33 as a switch, so that the low-voltage consumers can be supplied with the required power even in park mode. In the specific example, the micro-DC-DC converter would, for example,They would provide 12V and the converters 33 would be able to pass this 12V on to the low-voltage consumers without conversion, so that a supply to the key-off loads is ensured even in park mode.

[0049] The vehicle electrical system architecture according to the invention eliminates the need for a separate battery to supply the key-off loads. Instead, a micro-DC-DC converter, powered by the high-voltage battery, and a control unit are proposed that selectively ensures the supply of low-voltage consumers with either the first or the second low-voltage electrical system voltage, depending on the vehicle's state. Further, more complex architectural modifications are unnecessary, as, for example, the eFuse in the power distribution unit and converters in any existing zone control units can be used accordingly.

[0050] The proposed vehicle board can be easily and cost-effectively integrated into existing or future vehicle electrical system architectures. Integration costs are minimal, as the micro-DC-DC converter and the relatively simple control unit, which can ultimately function as a comparator, are inexpensive and cost-effective.

Claims

Patent claims 1. Vehicle electrical system (12) for an electric vehicle (10), comprising: a power distribution unit (18) for distributing electrical energy within the vehicle electrical system (12), a first DC-DC converter (22) that is connectable to the power distribution unit (18) and to a high-voltage battery (14) of the vehicle (10), wherein the first DC-DC converter (22) is configured to convert a high-voltage voltage provided by the high-voltage battery (14) of the vehicle into a first low-voltage electrical system voltage in the range of 24V to 60V, a second DC-DC converter (26) that is connectable to the high-voltage battery (14) of the vehicle (10) and is connectable to or connected to the power distribution unit (18), wherein the second DC-DC converter (26) is configured to convert the high-voltage voltage provided by the high-voltage battery (14) into a second Low-voltage electrical system voltageto convert the voltage in a range below the first low-voltage on-board network voltage, and in particular in a range of 5V to 16V, and a control unit (28) which is connected to the power distribution unit (18) and is configured to provide, in a first vehicle state, in particular when the vehicle (10) is in ferry operation, the first low-voltage on-board network voltage provided by the first DC-DC converter (22) to low-voltage consumers (16) of the vehicle's on-board network (12), and in a second vehicle state, in particular when the vehicle (10) is in parking mode, only the second low-voltage on-board network voltage provided by the second DC-DC converter (26) to the low-voltage consumers (16).

2. Vehicle electrical system (12) according to claim 1, wherein the second DC-DC converter (26) is connected to the power distribution unit (18) via a diode (34), the second DC-DC converter (26) provides the second low-voltage vehicle electrical system voltage in both the first and second vehicle states, and the diode (34) is configured such that, in the first vehicle state, the first low-voltage vehicle electrical system voltage provided by the first DC-DC converter (22) is not present at the second DC-DC converter (26) or no current flows into the second DC-DC converter (26).

3. Vehicle electrical system (12) according to claim 1 or 2, wherein the second DC voltage converter (26) is designed for a power output of a maximum of 15 watts, preferably a maximum of 10 watts, and more preferably a maximum of 5 watts.

4. Vehicle electrical system (12) according to one of claims 1 to 3, wherein the first DC voltage converter (16) is designed for a power output of at least 1000 watts.

5. Vehicle electrical system (12) according to one of claims 1 to 4, wherein the low-voltage consumers (16) are each connected to a converter (33) which has a half-bridge (36) with a high-side transistor circuit (38) and a low-side transistor circuit (40), wherein the converter (33) selectively provides either the first low-voltage vehicle electrical system voltage or the second low-voltage vehicle electrical system voltage for supplying the low-voltage consumers (16) by means of appropriate control by the control unit (28), and wherein the control unit (28) is further configured to control the high-side transistor circuit (38) and the low-side transistor circuit (40) in the first vehicle state such that the low-voltage consumers (16) can only be supplied with the first low-voltage vehicle electrical system voltage, and to open the low-side transistor circuit (40) and to close the high-side transistor circuit (38) in the second vehicle state.so that the low-voltage consumers (16) can only be supplied with the second low-voltage on-board power supply voltage.

6. Vehicle electrical system (12) according to one of claims 1 to 5, wherein the energy distribution unit (18) has a switching device (24) which is designed as an electrical safety device and has a first, closed switching state and a second, open switching state, and wherein the control unit (18) is further configured such that in the first vehicle state the first switching state of the switching device (24) is set, and that in the second vehicle state the second switching state of the switching device (24) is set.

7. Vehicle electrical system (12) according to one of claims 1 to 6, wherein the second DC voltage converter (26) is connected to the high-voltage battery (14) in such a manner, that the second DC-DC converter (26) provides the second low-voltage on-board power supply voltage in both the first and second vehicle states.

8. Vehicle electrical system (12) according to one of claims 1 to 7, wherein the first DC voltage converter (22) is connected to the high-voltage battery (14) in such a way that the first DC voltage converter (22) is only active in the first vehicle state.

9. Vehicle (10), in particular an electric vehicle or an electrically powered vehicle, with a vehicle electrical system (12) according to one of the preceding Claims.

Images