VEHICLE ELECTRICAL SYSTEM

Abstract

In a vehicle electrical system, a method supplies a number of consumers of the system, which consumers are classified with different safety classifications, the differently classified consumers being supplied power from either one or more of a plurality of electrical subsystems according to their classifications or lack of classification.

Claims

1-11. (canceled)

12. An electrical system comprising: a plurality of electrical subsystems that each includes its own energy supply; a plurality of consumers, wherein: at least one of the consumers, which is classified with an average safety classification, is able to be supplied with power from at least two of the electrical subsystems; and at least one of the consumers, which is not classified with a safety classification, is able to be supplied with power from only one of the electrical subsystems.

13. The electrical system of claim 12, further comprising: at least one switch via which the at least one consumer classified with the average safety classification is supplied from the at least two of the electrical subsystems.

14. The electrical system of claim 12, further comprising: at least one switch by which at least one of the electrical subsystems is separable from the electrical system.

15. The electrical system of claim 12, further comprising: at least one switch by which one of the consumers is separable from the electrical system.

16. The electrical system of claim 12, wherein the at least one consumer classified with the average safety classification is situated symmetrically between two of the electrical subsystems.

17. The electrical system of claim 12, wherein the electrical system is part of a motor vehicle.

18. The electrical system of claim 12, wherein the electrical system is part of a mobile work machine.

19. The electrical system of claim 12, wherein the energy supplies of the electrical subsystems are located in a base vehicle electrical system.

20. A method for supplying a consumer classified with an average safety classification and a consumer not classified with a safety classification, the method comprising: supplying power to the consumer classified with the average safety classification from at least two of a plurality of vehicle electrical subsystems; supplying power to the consumer that is not classified with a safety classification from only one of the plurality of vehicle electrical subsystems.

21. The method of claim 20, further comprising: separating at least one of the consumers from at least one of the electrical subsystems by operating a switch.

22. The method of claim 20, further comprising: separating at least one of the electrical subsystems from a vehicle electrical system by operating at least one switch.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 is a diagram of a circuit system according to an example embodiment of the present invention.

[0021] FIG. 2 is a diagram of a circuit system according to another example embodiment of the present invention.

[0022] FIG. 3 is a diagram of a circuit system according to another example embodiment of the present invention.

DETAILED DESCRIPTION

[0023] Example embodiments of the present invention are schematically shown in the figures and are described in detail in the following text with reference to those figures.

[0024] Consumers are basically able to be subdivided into multiple categories in accordance with their safety relevance. The topologies introduced in the following text are based on consumers of the following three categories. [0025] Consumer R1: high safety relevance and redundant supply, where the consumer is assigned a high safety classification; [0026] Consumer R2: average safety relevance, where the consumer is assigned an average safety classification; and [0027] Consumer R3: no safety relevance, where the consumer is assigned no safety classification.

[0028] FIG. 1 shows a vehicle electrical system 10 according to an example embodiment, in which a consumer having an average safety relevance is supplied from two vehicle electrical subsystems. The illustration shows a first vehicle electrical subsystem 12 and a second vehicle electrical subsystem 14. A first generator 16 and a first battery 18 are allocated to first vehicle electrical subsystem 12. A second generator 20 and a second battery 22 are allocated to second vehicle electrical subsystem 14. In addition, the illustration shows a consumer R3a 24, a consumer R2 26, and a consumer R3b 28. Moreover, a first switch unit 30 having a first switch 32 and a first diode 34 as well as a second switch unit 40 having a second switch 42 and a second diode 44 are depicted.

[0029] Hereinafter, consumers R3a 24 and R3b 28 are independent consumers of safety category 3, or in other words, they are consumers without safety relevance. This means that no redundant supply of a consumer is involved as would be the case with consumers of category 1, i.e., consumers of high safety relevance. Consumer R2 26 is a consumer of safety category 2 and thus a consumer of average safety relevance. It is disposed symmetrically with respect to the two vehicle electrical subsystems 12, 14.

[0030] The consumers are integrated into vehicle electrical system 10 in accordance with this classification. As described at the outset, in the vehicle electrical system topologies introduced herein, consumers having at most an average safety relevance are supplied predominantly or even exclusively. Vehicle electrical system 10 of FIG. 1 is basically made up of the two vehicle electrical subsystems 12, 14 to the left and right; each has a generator 16 or 20 and battery 18 or 22, which supply a consumer of average safety relevance, i.e., consumer R2 26, by way of intelligent switch units 30, 40. Intelligent switch units 30, 40 have a diode function, which means that they permit a current flow only from one of the vehicle electrical subsystems 12 or 14 to consumer R2 26. In the event that a source, e.g., a generator 16 or 20, of a vehicle electrical subsystem 12 or 14 causes an overvoltage, respective intelligent switch unit 20 or 40 carries out a separation as well. Generators 16, 20 may exist as two separate generators 16, 20 or as two generators 16, 20 on a shaft and possibly inside a housing.

[0031] The advantage of the topology in FIG. 1 is that if either the right or the left vehicle electrical subsystem 12 or 14 fails completely, e.g., also with a short circuit, the supply of consumer R2 26 is still ensured on a permanent basis. In theory it is also possible to supply a plurality of consumers of category 2 in parallel. However, it must then be ensured that no such consumer causes a short circuit or an overvoltage that leads to the failure of the other consumers.

[0032] If no permanent supply independent of a random single fault is required, then an example topology according to FIG. 2 can be selected, including a vehicle electrical system having two vehicle electrical subsystems, including a battery in each case, which are supplied from a generator. FIG. 2 shows a vehicle electrical system, which is denoted by reference numeral 100 as a whole. It includes a first vehicle electrical subsystem 102 and a second vehicle electrical subsystem 104. Both vehicle electrical subsystems 102, 104 are allocated a generator 106. It supplies a first battery 108 in first vehicle electrical subsystem 102 and a second battery 110 in second vehicle electrical subsystem 104.

[0033] The illustration furthermore shows a first switch unit S1a 120 having a first switch 122 and a first diode 124, a second switch unit S1b 130 having a second switch 132 and a second diode 134, a third diode D2a 140, a fourth diode 142, a consumer R3a 150, a consumer R2 152, as well as a consumer R3b 154.

[0034] In this specific example embodiment, a generator is dispensed with and the two vehicle electrical subsystems 102, 104, each having a respective battery 108 and 110, are supplied via a single generator, i.e., generator 106, and if necessary, are decoupled from it via intelligent switch units S1a 120, S1b 130. If generator 106 causes a short circuit or an overvoltage, then both vehicle electrical systems 102, 104 are separated from it and may continue to operate until batteries 108, 110 are drained. Consumer R2 152, which represents a consumer of average safety relevance, can thus still be supplied until both vehicle electrical subsystems 102, 104 have failed.

[0035] Instead of diodes D2a 140 and D2b 142, it is also possible to use intelligent switches that have a diode function. If generator 106 fails in such a case, then the driver should be warned that his or her vehicle or safety-related systems might fail in the foreseeable future. In the event of a battery short circuit, affected battery 108 or 110 is separated from consumer R2 152 via corresponding diode 140 or 142, and generator 106 is likewise separated from battery 108 or 110 via intelligent switch unit 120 or 130. Consumer R2 152, having an average safety relevance, can continue to be supplied via other battery 108 or 110. During the operation, consumer R3a 150 without safety relevance is supplied from first vehicle electrical subsystem 102, and consumer R3b 154 without safety relevance is supplied from second vehicle electrical subsystem 104.

[0036] To simplify matters, it is also possible to omit the second battery. An example of such a topology including a generator and a battery is illustrate in FIG. 3. FIG. 3 shows a vehicle electrical system 200.

[0037] In this case, a vehicle electrical subsystem made up of generator and consumer could be indicated in the event of a failure of the battery, and a vehicle electrical subsystem made up of battery and consumer could be indicated in the event of a failure of the generator.

[0038] The illustration shows a generator 206, a battery 208, a first switch 210 parallel to a first diode D1 212, a switch unit 220 having a switch S1 222 and a diode 224, a switch S2 226 in series with a second diode 228, a switch S3 230 as well as a consumer R2 240 of average safety relevance, a consumer R3a 242 with no safety relevance, and a consumer R3b 244 with no safety relevance.

[0039] In this specific example embodiment, consumer R2 240 having an average safety relevance may be supplied either by way of generator 206 or battery 208 in the event that the other component fails. Generator 206 may fail both with a short circuit and an overvoltage. Vehicle electrical system 200 is effectively shielded from such a failure via switch S1 222 or switch S2 226. A battery, in this case battery 206, exhibits no overvoltage. As a result, only the short circuit of battery 208 is separated from vehicle electrical system 200 via diode D1 212.

[0040] However, in this case it should be taken into account that with a non-available battery 208, its buffer effect is lost as well. Consumers that draw steep and high power pulses from vehicle electrical system 200 are therefore unable to be supplied or can be supplied only with derating, i.e., choking. Provided battery 208 exhibits no short circuit, and parallel first switch 210 enables charging also via energy currents from vehicle electrical system 200, e.g., during braking of electrical drives.

[0041] If a consumer without safety relevance, in this case consumer R3a 242 or consumer R3b 244, causes a short circuit or an overvoltage, such an event is kept away from consumer R2 240 by switch S3 230 opening. Switch unit 220 between battery 208 and generator 206 prevents that a short circuit of generator 206 or battery 208 also short-circuits the respective other component, and enables charging of battery 208 by generator 206.

[0042] In the illustrated specific example embodiments of FIGS. 1 through 3, switches are therefore provided by which back-and-forth switching between the two vehicle electrical subsystems is possible for consumer R2 with an the average safety classification. In addition, switches are provided that make it possible to separate vehicle electrical subsystems, energy supplies, i.e., battery and/or generator, and/or consumers from the vehicle electrical system.