VEHICLE ELECTRICAL SYSTEM AND POWER MODULE THEREFOR

Abstract

A vehicle electrical system for a vehicle includes first and second subsystems, each connected to at least one energy source. The first and second subsystems have different voltage levels. At least one safety-relevant load is connected to one of the subsystems, this subsystem having two partial systems, and the load being connected to both partial systems so that the load is connected to the energy source of the subsystem via two separate supply lines. A power module, which connects the two subsystems to each other and is designed such that each of the two supply lines can be connected to both energy sources so that the load can be supplied from both energy sources via both supply lines. There is also described a corresponding power module.

Claims

1.-15. (canceled)

16. A vehicle electrical system for use in a vehicle, the electrical system comprising: a first electrical subsystem and a second electrical subsystem; each of said first and second electrical subsystems being connected to at least one energy source and said first electrical subsystem having a different voltage level than said second electrical subsystem; at least one safety-relevant consumer connected to one of said first or second electrical subsystems, wherein said one electrical subsystem has two component electrical systems and said consumer is connected to both said two component electrical systems, with said consumer being connected to said energy source of said one electrical subsystem via two separate power supply lines; a power module connecting said first and second electrical subsystems to one another, and configured to connect each of said two separate power supply lines to said two energy sources, and enabling power to be supplied to said consumer in each case from said two energy sources via both said two power supply lines.

17. The vehicle electrical system according to claim 16, wherein: said energy source of a respective electrical subsystem is connected directly only to said respective electrical subsystem and is connected to the other said electrical subsystem only indirectly via said power module; and said consumer is connected directly only to one said electrical subsystem and is connected to the other said electrical subsystem only indirectly via said power module.

18. The vehicle electrical system according to claim 16, wherein said first electrical subsystem has a lower voltage level than said second electrical subsystem.

19. The vehicle electrical system according to claim 16, wherein said consumer is connected to a respective said electrical subsystem which has a higher voltage level.

20. The vehicle electrical system according to claim 16, wherein said first electrical subsystem has a voltage level of 12 V, said second electrical subsystem has a voltage level of 48 V, and said consumer is connected to said second electrical subsystem.

21. The vehicle electrical system according to claim 16, wherein: a first electrical storage device is connected as a first energy source to said first electrical subsystem; a second electrical storage device is connected as a second energy source to said second electrical subsystem; and a generator is connected as an additional energy source.

22. The vehicle electrical system according to claim 16, wherein said generator and said second electrical storage device are connected to different component electrical systems of said second electrical subsystem.

23. The vehicle electrical system according to claim 16, wherein said power module has at least one DC-DC converter, configured to connect said first and second electrical subsystems to one another and to supply energy from said first electrical subsystem to said second electrical subsystem, and vice versa.

24. The vehicle electrical system according to claim 16, wherein: each of said first and second electrical subsystems has two component electrical systems, and the power module has two DC-DC converters, which represent a boundary between said first and second electrical subsystems; a first of said two DC-DC converters connects a first component electrical system of said first electrical subsystem to a first component electrical system of said second electrical subsystem; and a second of said two DC-DC converters connects a second component electrical system of said first electrical subsystem to a second component electrical system of said second electrical subsystem; wherein in each case two component electrical systems from different electrical subsystems are connected via a DC-DC converter.

25. The vehicle electrical system according to claim 16, wherein: each of said first and second electrical subsystems has two component electrical systems; said two component electrical systems of said first electrical subsystem are disconnectably connected to one another via a first switch; and said two component electrical systems of said second electrical subsystem are disconnectably connected to one another via a second switch.

26. The vehicle electrical system according to claim 25, wherein said first and second switches are integrated in said power module.

27. The vehicle electrical system according to claim 25, wherein said power module comprises a dedicated terminal for each of said component electrical systems.

28. The vehicle electrical system according to claim 16, wherein each of said first and second electrical subsystems has an electrical storage device forming said at least one energy source and each is integrated in said power module.

29. The vehicle electrical system according to claim 16, wherein at least one comfort consumer is connected in the vehicle electrical system, which comfort consumer is not safety-relevant and which is connected to one of said energy sources via only one power supply line.

30. A power module for a vehicle electrical system having two electrical subsystems each connected to at least one energy source and having different voltage levels, the power module comprising: connection lines for connecting the two electrical subsystems to one another, and to connect two separate power supply lines to two energy sources of the electrical subsystems; the power module being configured for supplying power to a consumer in each case from the two energy sources via both said two separate power supply lines.

Description

[0036] In the text which follows, exemplary embodiments of the invention will be explained in more detail with reference to a drawing, in which, in each case schematically:

[0037] FIG. 1 shows a vehicle having a vehicle electrical system,

[0038] FIG. 2 shows a first variant of the vehicle electrical system from FIG. 1,

[0039] FIG. 3 shows a second variant of the vehicle electrical system from FIG. 1.

[0040] FIG. 1 shows a vehicle 2, which has a vehicle electrical system 4, which is merely indicated in very schematized form by connecting lines between a plurality of components of the vehicle 2. The vehicle 2 is a motor vehicle, for example a passenger vehicle or a heavy-goods vehicle, and is driven for example electrically or by an internal combustion engine or both. FIG. 2 shows, in more detail, an exemplary embodiment of a first variant of the vehicle electrical system 4, and FIG. 3 shows, in more detail, an exemplary embodiment of a second variant.

[0041] The vehicle electrical system 4 generally has a first electrical subsystem 6 and a second electrical subsystem 8, to which in each case at least one energy source 10, 12, 14 is connected. The first electrical subsystem 6 has a different, in this case a lower, voltage layer than the second electrical subsystem 8. At least one first energy source 10 is connected to the first electrical subsystem 6, and at least one second energy source 12 is connected to the second electrical subsystem 8. The energy source 10, 12, 14 of the respective electrical subsystem 6, 8 fixes the voltage layer thereof. In the exemplary embodiments shown, the voltage layer of the first electrical subsystem 6 is 12 V, and the voltage layer of the second electrical subsystem 8 is 48 V, but in principle other voltages are also possible and suitable.

[0042] The vehicle electrical system 4 has at least one, and in this case by way of example four, safety-relevant consumers 16, which are each connected to one of the electrical subsystems 6, 8. In this case, each electrical subsystem 6, 8 has two component electrical systems 18, 20, 22, 24, and a respective consumer 16 is connected to the two component electrical systems 18, 20, 22, 24 of a single electrical subsystem 6, 8, with the result that the consumer 16 is connected to the energy source 10, 12, 14 of the corresponding electrical subsystem 6, 8 via two separate power supply lines V1, V2. This is shown by way of example in FIGS. 2 and 3 for one of the consumers 16, but as will become clear, all four consumers 16 are each connected separately via two connecting lines V1, V2. The respective energy source 10, 12, 14 is connected to only one of the component electrical systems 18, 20, 22, 24, but the two component electrical systems 18, 20, 22, 24 of a respective electrical subsystem 6, 8 are connected to one another in such a way that power is supplied to the two component electrical systems 18, 20, 20, 24 from the associated energy source 10, 12, 14. Therefore, each of the two electrical subsystems 6, 8 is divided into two component electrical systems 18, 20, 22, 24, which both each comprise one of the power supply lines V1, V2, with the result that energy can be supplied to the consumer 16 via different component electrical systems 18, 20, 22, 24, i.e. said consumer is connected to the energy source 10, 12, 14 with redundancy. One or more comfort consumers 26 which may be present are in contrast each connected only to a single component electrical system 18, 20, 22, 24, i.e. are not supplied power with redundancy.

[0043] The safety-relevant consumers 16 each perform a safety-relevant function and serve the purpose of ensuring the safety and the integrity of the vehicle 2 or one or more occupants of a vehicle 2 or other road users in a reliable and operationally safe manner. Safety-relevant consumers of a vehicle are, for example, as shown in FIG. 1, a brake system or a steering system or, in a variant which is not shown, alternatively or additionally active roll stabilization, a drive system, a chassis control system, an airbag, a system for ensuring the vehicle stability or the like. Safety-relevant consumers 16 should be distinguished from comfort consumers 26, which do not actually perform any safety-relevant function, but merely one or more comfort functions. Examples of comfort consumers 26 are a seat adjustment system, as can be seen in FIG. 1, or alternatively or in addition an air-conditioning system, an audio system or the like.

[0044] Furthermore, the vehicle electrical system 4 has a power module 28, which connects the two electrical subsystems 6, 8 to one another, and which is designed in such a way that each of the two power supply lines V1, V2 is connectable to all of the energy sources 10, 12, 14, with the result that power can be supplied to the consumer 16 via the two power supply lines V1, V2 in each case from all of the energy sources 10, 12, 14. The consumer 16 is therefore connected not only to an individual energy source 10, 12, 14 in the same electrical subsystem 6, 8 with redundancy, but is also connected to one or more energy sources 10, 12, 14 from the other electrical subsystem 6, 8. In addition to the redundancy of the connection, accordingly also a redundancy of the energy supply is realized.

[0045] The power module 28 is overall used for distributing the electrical energy from the energy sources 10, 12, 14 amongst the various electrical subsystems 6, 8 and component electrical systems 18, 20, 22, 24 and therefore ensures the described redundancy of the energy supply to the consumer 16. The power module 28 in the exemplary embodiments shown is an electrical circuit, which in this case has a printed circuit board 30, on which suitable component parts for realizing the functionality of the power module 28 are arranged and interconnected.

[0046] A respective energy source 10, 12, 14 is connected directly only to one of the electrical subsystems 6, 8 and is connected to the other electrical subsystem 6, 8 only indirectly via the power module 28. The same similarly applies to the consumers 16 and also to the comfort consumers 26, which are each connected directly only to one electrical subsystem 6, 8, but to the other electrical subsystem 6, 8 only indirectly via the power module 28. A respective energy source 10, 12, 14 is additionally also connected only to one of the component electrical systems 18, 20, 22, 24 and is therefore connected to the remaining component electrical systems 18, 20, 22, 24 only indirectly, namely via the power module 28. A respective consumer 16, on the other hand, is connected directly to at least two component electrical systems 18, 20, 22, 24 of one of the electrical subsystems 6, 8, with the result that a redundant link is realized. A respective comfort consumer 26, on the other hand, is connected to only one component electrical system 18, 20, 22, 24.

[0047] As described already, the first electrical subsystem 6 in FIGS. 2 and 3 has a voltage layer of 12 V, and the second electrical subsystem 8 has a higher voltage layer than this of 48 V. A particular feature is that at least one safety-relevant consumer 16 is connected to the second electrical subsystem 8 and is operated on the higher voltage and in this case is supplied energy with redundancy. This is in principle independent of which and how many consumers 16 and comfort consumers 26 are connected to the first electrical subsystem 6 at 12 V and how the energy sources 10, 12, 14 are distributed.

[0048] The energy sources 10, 12 are in this case in each case in the form of electrical stores, in this case even in the form of a battery. As an alternative, a configuration as a supercap is also suitable. A generator is also suitable as energy source 14. In the exemplary embodiments shown, a first electrical store is connected as first energy source 10 to the first electrical subsystem 6, and a second electrical store is connected as second energy source 12 to the second electrical subsystem 8, and a generator is connected as an additional energy source 14, with the result that the shown vehicle electrical systems 4 each have three energy sources 10, 12, 14. Alternatives with a different number of and distribution of energy sources 10, 12, 14 are in principle possible and also suitable if at least one energy source 10, 12, 14 is connected to each of the electrical subsystems 6, 8, with the result that at least one energy source 10, 12, 14 is provided per electrical subsystem 6, 8.

[0049] In the exemplary embodiments in FIGS. 2 and 3, the generator 14 and the second electrical store 12 are connected to different component electrical systems 22, 24 of the second electrical subsystem 8. This is not essential per se, but has the advantage that the two energy sources 12, 14 of the second electrical subsystem 8 are distributed among different component electrical systems 22, 24 and, in the event of a fault in one of the component electrical systems 22, 24, potentially only one energy source 12, 14 fails, while the other can continue to be used. This concept is similarly also applicable to the first electrical subsystem 6.

[0050] The power module 28 connects the two electrical subsystems 6, 8 and therefore also different voltage layers. In order to supply energy to one electrical subsystem 6, 8 from the other electrical subsystem 6, 8, and vice versa, the power module 28 has at least one and in this case two DC-DC converters 32, 34, via which the two electrical subsystems 6, 8 are connected to one another. The DC-DC converters 32, 34 serve to convert the voltage layers and are in this case specifically in each case in the form of 48 V/12 V converters. The DC-DC converters 32, 34 also represent a boundary between the two electrical subsystems 6, 8.

[0051] In the configurations shown in FIGS. 2 and 3, the first electrical subsystem 6 has a first component electrical system 18 and a second component electrical system 20, and the second electrical subsystem 8 likewise has a first component electrical system 22 and a second component electrical system 24. The first DC-DC converter 32 connects the first component electrical system 18 of the first electrical subsystem 6 to the first component electrical system 22 of the second electrical subsystem 8. The second DC-DC converter 34 similarly connects the second component electrical system 20 of the first electrical subsystem 6 to the second component electrical system 24 of the second electrical subsystem 8. Therefore, on the one hand, the first component electrical systems 18, 22 and the second component electrical systems 20, 24 are connected via a respective DC-DC converter 32, 34. Since the component electrical systems 18, 20, 22, 24 of an electrical subsystem 6, 8 are also connected to one another, even in the event of a fault in one of the DC-DC converters 32, 34, power can continue to be supplied to each component electrical system 18, 20, 22, 24 and each consumer 16 connected thereto from any other component electrical system 18, 20, 22, 24 to which an energy source 10, 12, 14 is connected.

[0052] The two component electrical systems 18, 20 of the first electrical subsystem 6 are connected disconnectably to one another via a first switch 36. Similarly, the two component electrical systems 22, 24 of the second electrical subsystem 8 are also connected disconnectably to one another via a second switch 38. The switches 36, 38 serve to disconnect a respective component electrical system 18, 19, 22, 24 in the event of a fault by virtue of the corresponding switch 36, 38 being opened. Moreover, i.e. during normal operation and without a fault event, the switches 36, 38 are closed, on the other hand. In the exemplary embodiments shown, the two switches 36, 38 are integrated in the power module 28, namely on the printed circuit board 30. In a variant which is not shown, the DC-DC converters 32, 34 are also fitted on the printed circuit board 30.

[0053] As becomes clear from FIGS. 2 and 3, the switches 36, 38 connect a respective first component electrical system 18, 22 to the associated second component electrical system 20, 24 within the same electrical subsystem 6, 8, whereas the DC-DC converters 32, 34 connect the different electrical subsystems 6, 8 to one another. By virtue of corresponding switchover of the switches 36, 38 and of the DC-DC converters 32, 34, the component electrical systems 18, 20, 22, 24 can be connected to one another and disconnected from one another virtually as desired.

[0054] In this case, the power module 28 has a dedicated terminal 40 for each component electrical system 18, 20, 22, 24, i.e. in this case four terminals 40. As a result, the component electrical systems 18, 20, 22, 24 of an electrical subsystem 6, 8 are merely connected to one another via the power module 28 and at the consumers 16. The terminals 40 are in each case in the form of a pole to which the consumers 16, comfort consumers 26 and energy sources 10, 12, 14 of the respective component electrical system 18, 20, 22, 24 are connected outside the power module 28. The terminals 40 of a respective electrical subsystem 6, 8 are connected via one of the switches 36, 38. On the other hand, one of the DC-DC converters 32, 34 is arranged between two terminals 40 of different electrical subsystems 6, 8.

[0055] A respective energy source 10, 12, 14 is either arranged outside the power module 28 and separately therefrom, as shown in FIG. 2, or alternatively is integrated in the power module 28, as shown in FIG. 3. Specifically in FIG. 3, the energy sources 10, 12 in the form of electrical stores are integrated in the power module 28, whereas the generator 14, as in FIG. 2, is arranged outside the power module 28. The power module 28 in FIG. 3 therefore has an energy source 10, 12 in the form of an electrical store for each of the two electrical subsystems 6, 8, with the result that such an electrical store does not also need to be connected externally in addition.

LIST OF REFERENCE SYMBOLS

[0056] 2 vehicle

[0057] 4 vehicle electrical system

[0058] 6 first electrical subsystem (12 V)

[0059] 8 second electrical subsystem (48 V)

[0060] 10 first energy source, first electrical store

[0061] 12 second energy source, second electrical store

[0062] 14 energy source, generator

[0063] 16 safety-relevant consumer

[0064] 18 first component electrical system (in the first electrical subsystem)

[0065] 20 second component electrical system (in the first electrical subsystem)

[0066] 22 first component electrical system (in the second electrical subsystem)

[0067] 24 second component electrical system (in the second electrical subsystem)

[0068] 26 comfort consumer

[0069] 28 power module

[0070] 30 printed circuit board

[0071] 32 first DC-DC converter

[0072] 34 second DC-DC converter

[0073] 36 first switch

[0074] 38 second switch

[0075] 40 terminal

[0076] V1, V2 connecting line