ELECTRONIC VOLTAGE SUPPLY SYSTEM

Abstract

An electronic voltage supply system includes a first battery string providing an electrical medium voltage at a first battery output and a second battery string providing the medium voltage at a second battery output. A potential distributor has a plurality of electrical low-voltage connections, each of which is connectable to the first and/or battery strings via a voltage transformer unit. The voltage transformer unit reduces the medium voltage provided by the first or second battery string to a low voltage. The system also includes first and second medium-voltage paths, which can be or is electrically connected to the first and/or second battery string and a first or second medium-voltage connection at which the medium voltage generated by the first or second battery string is provided. The system further includes a bridge circuit that connects the first medium voltage connection and the at least one second medium-voltage terminal to the first and/or second battery string.

Claims

1-17. (canceled)

18. An electronic voltage supply system for providing electrical energy to a battery module, the electronic voltage supply system comprising: a first battery string, which outputs an electrical medium voltage at a first battery output; a second battery string, which outputs the medium voltage at a second battery output; a potential distributor having a plurality of electrical low-voltage connections, each of which is connectable to the first and second battery strings via a voltage transformer unit, wherein the voltage transformer unit is configured to reduce the medium voltage provided by the first and second battery strings to a low voltage; a first and second medium-voltage connection, at which the medium voltage generated by the first or second battery string is provided; and a bridge circuit configured to connect each of the plurality of low-voltage connections, the first medium voltage connection, and the second medium-voltage connection to the first or second battery string.

19. The electronic voltage supply system of claim 18, wherein the voltage transformer unit comprises: a first voltage transformer configured to connect the plurality of low-voltage connections, via the bridge circuit, to the first or second battery string; and a second voltage transformer configured to connect the plurality of low-voltage connections, via the bridge circuit, to the first or second battery string.

20. The electronic voltage supply system of claim 19, wherein the electronic voltage supply system is configured so that if there is a simultaneous failure of one of the first and second battery strings and one of the first and second voltage transformers, the medium voltage generated by a remaining one of the first and second battery strings is reduced to the low voltage by the bridge circuit by a remaining one of the first and second voltage transformers and is provided to the plurality of low-voltage connections.

21. The electronic voltage supply system of claim 18, wherein the bridge circuit has a bridging path connecting first and second medium-voltage paths between the first and second battery strings and the medium-voltage connections.

22. The electronic voltage supply system of claim 21, further comprising: a plurality of electrical or electronic switches, each of which is adjustable between an open state and a closed state, wherein a respective switch of the plurality of electrical or electronic switches, in the open state, electrically interrupts a line path section in which the respective switch is arranged, and in the closed state cancels the interruption; a control/regulation device configured to switch each of the plurality of electrical or electronic switches between the open state and the closed state.

23. The electronic voltage supply system of claim 18, wherein the voltage supply system has a nominal system state, a first battery string fault state, and a second battery string fault state and is adjustable or switchable at least between the nominal system state, the first battery string fault state, and the second battery string fault state, in the nominal system state, the bridge circuit is configured in such a way that the first medium voltage connection is connected to the first battery string and the second medium voltage connection is connected to the second battery string, in the first battery string fault condition, the bridge circuit configured in such a way that the first and second medium voltage connections are connected to the second battery string, and in the second battery string fault state, the bridge circuit is configured in such a way that the first and second medium voltage connections are connected to the first battery string.

24. The electronic voltage supply system of claim 23, wherein in the first battery string fault state, the voltage transformer unit is set in such a way that the plurality of low-voltage connections are connected to the second battery string, and in the second battery string fault state, the voltage transformer unit is set in such a way that the plurality of low-voltage connections are connected to the first battery string.

25. The electronic voltage supply system of claim 23, wherein the electronic voltage supply system has a first and second voltage transformer fault state that are combinable with the first and second battery string fault states, the plurality of low-voltage connections of the potential distributor are connected to the first or second battery string via the second voltage transformer in the first voltage transformer fault state and via the first voltage transformer in the second voltage transformer fault state.

26. The electronic voltage supply system of claim 22, wherein the plurality of electrical or electronic switches comprise: one first switch is arranged between the bridging path of the bridge circuit and the first medium-voltage connection in a first medium-voltage path; a second first switch is arranged in each case between the bridging path of the bridge circuit and the second medium-voltage connection in a second medium-voltage path; one second switch is arranged between the bridging path of the bridge circuit in the first medium-voltage path and the first battery string; and another second switch is arranged between the bridging path of the bridge circuit in the second medium-voltage path and the second battery string.

27. The electronic voltage supply system of claim 26, wherein the plurality of electrical or electronic switches further comprise: a third switch provided between each of the first and second voltage transformers and the first or second battery strings; and a fourth switch provided between each of the first and second voltage transformers and the plurality of low-voltage connections of the potential distributor.

28. The electronic voltage supply system of claim 27, wherein the plurality of electrical or electronic switches further comprise: a fifth switch provided at all of the low-voltage connections of the potential distributor.

29. The electronic voltage supply system of claim 28, further comprising: a sixth switch provided at the first battery output and at the second battery output.

30. A battery module for a motor vehicle, the battery module comprising: an electronic voltage supply system, which comprises a first battery string, which outputs an electrical medium voltage at a first battery output; a second battery string, which outputs the medium voltage at a second battery output; a potential distributor having a plurality of electrical low-voltage connections, each of which is connectable to the first and second battery strings via a voltage transformer unit, wherein the voltage transformer unit is configured to reduce the medium voltage provided by the first and second battery strings to a low voltage; a first and second medium-voltage connection, at which the medium voltage generated by the first or second battery string is provided; and a bridge circuit configured to connect each of the plurality of low-voltage connections, the first medium voltage connection, and the second medium-voltage connection to the first or second battery string; at least one first electrical consumer connected to one of the plurality of low-voltage connections to supply the at least one first electrical consumer with the low voltage; at least one second electrical consumer connected to the first or second medium-voltage terminal to supply the at least one second electrical consumer with the medium voltage.

31. The battery module of claim 30, further comprising: at least one DC-DC or DC-AC converter connected to the first or the second medium-voltage connection, wherein the at least one DC-DC or DC-AC converter is configured to raise the medium voltage to a DC or AC voltage of a higher value.

32. The battery module of claim 30, wherein the at least one first electrical consumer is: a fan for cooling an internal combustion engine of a motor vehicle, a braking device for braking the motor vehicle, a vehicle steering device for steering the motor vehicle, or a lighting device for illuminating a vehicle interior of the motor vehicle.

33. The battery module of claim 32, wherein the at least one second electrical consumer is: a PTC heater for heating the vehicle interior of the motor vehicle, a refrigerant compressor of an air conditioning system in the motor vehicle, or a starter generator for starting the internal combustion engine of the motor vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0030] Preferred exemplary embodiments of the invention are depicted in the drawings and will be explained in more detail in the following description, wherein identical reference numerals refer to identical or similar or functionally identical components.

[0031] Here are shown, schematically in each case:

[0032] FIG. 1 an example of a voltage supply system according to the invention in a depiction in the manner of a circuit diagram,

[0033] FIG. 2 an example of a battery module according to the invention having a voltage supply system according to the invention in a schematic, highly simplified depiction.

DETAILED DESCRIPTION

[0034] FIG. 1 illustrates, in a depiction in the manner of a circuit diagram, an example of an electronic voltage supply system 1 for providing electrical energy in a motor vehicle. The voltage supply system 1 comprises a first battery string 2a, which provides a medium voltage U.sub.MS at a first battery output 12a. The voltage supply system 1 further comprises a second battery string 2b, which provides the same electrical medium voltage U.sub.MS at a second battery output 12b as the first battery string 2a provides at the first battery output 12a. Typically, the first and second battery strings 2a, 2b each comprise the same number of rechargeable batteries 20 electrically connected in series. The voltage supply system 1 further comprises a so-called potential distributor 14 for distributing the low voltage U.sub.NS with a plurality of electrical low-voltage connections 4, each of which can be selectively connected to the first or second battery strings 2a, 2b via a voltage transformer unit 5. For this purpose, a first electrical supply path 3a extends from the voltage transformer unit 5 to the first battery terminal 12a and a second electrical supply path 3b extends to the second battery connection 12b. The voltage transformer unit 5 is designed in such a way that it reduces the medium voltage U.sub.MS provided by the first or second battery string 2a, 2b to a low voltage U.sub.NS, which is thus available at the low-voltage connections 4. Expediently, the medium voltage U.sub.MS is 48 volts and the low voltage U.sub.NS is 12 volts.

[0035] According to FIG. 1, the voltage transformer unit 5 comprises a first voltage transformer 5a, by means of which the low-voltage connections 4 can be connected to the first battery string 2a. Furthermore, the voltage transformer unit 5 comprises a second voltage transformer 5b, by means of which the low-voltage connections 4 can be connected to the second battery string 2b. Each of the two voltage transformers 5a, 5b contains in a known manner a choke 21 and electronic switches 22 for voltage transformation of the medium voltage U.sub.MS to the low voltage U.sub.NS.

[0036] Furthermore, the voltage supply system 1 comprises a first medium voltage path 6a and a second medium voltage path 6b electrically connected to the first battery string 2a and to the second battery string 2b, and has a first and a second medium voltage connection 7a, 7b, in which the medium voltage U.sub.MS generated by the first or second battery string 2a, 2b is provided. Furthermore, the voltage supply system 1 comprises a bridge circuit 8 via which both the first medium voltage connection 7a and the second medium voltage connection 7b can be connected to the first and second battery strings 2a, 2b independently of each other. The bridge circuit 8 is configured so as to be adjustable between different circuit states. Depending on the set circuit state, the first medium voltage connection 7a is connected to the first and/or second battery string 2a, 2b. Likewise, depending on the set circuit state, the second medium-voltage connection 7b is optionally connected to the first or second battery string 2a, 2b. The bridge circuit 8 also has a bridging path 9, which is arranged between the battery strings 2a, 2b and the medium-voltage connections 7a, 7b and connects the first medium-voltage path 6a to the second medium-voltage path 6b.

[0037] The voltage supply system 1 further comprises a control/regulation device 25. The control/regulation device 25 serves to control the two battery strings 2a, 2b as well as the two voltage transformers 5a, 5b of the voltage transformer unit 5.

[0038] In the example of FIG. 1, the control/regulation device 25 has a main control unit 26 by means of which four further auxiliary control units 27a, 27b, 27c, 27d can be controlled. All four auxiliary control units 27a to 27d are in communication with the main control unit 26. These communication links are indicated in FIG. 1 by arrows marked with the reference numeral 11. The four auxiliary control units 27a to 27d are used to control the battery strings 2a, 2b and the two voltage transformers 5a, 5b. The first auxiliary control unit 27a controls the first battery string 2a. The second auxiliary control unit 27b controls the second battery string 2b. The third auxiliary control unit 27c controls the first voltage transformer 5a. The fourth auxiliary control unit 27d controls the second voltage transformer 5b. The main control unit 26 can be connected to a field bus—for example a LIN or CAN bus—of the motor vehicle via a communication interface 13.

[0039] The voltage supply system 1 further comprises several electrical or electronic switches 10, which are assigned to the aforementioned components of the voltage supply system 1 and can be controlled by the control/regulation device 25—in particular by the main control unit 26. In this way, different system states can be implemented in the voltage supply system 1. In particular, it is thus possible to react to different fault states that may occur in the voltage supply system 1.

[0040] Typically, each of the switches 10 is a transistor, preferably a field effect transistor (FET), most preferably a metal oxide field effect transistor (MOSFET). Each switch 10 can be switched or adjusted by the control device 25 at least between an open state and a closed state. In the open state, the respective switch 10 interrupts the line path in which the switch 10 is arranged and cancels this interruption in the closed state. The switch 10 thus fulfils an electrical disconnecting or interrupting function in a known manner.

[0041] The voltage supply system 1 can be switched or adjusted between different states with the aid of the switch 10, which will be explained in more detail below. First, the various switches 10 installed in the voltage supply system 1 will be discussed:

[0042] Between the bridging path 9 of the bridge circuit 8 and the first and second medium-voltage terminals 7a, 7b, a first switch 10.1 is provided in each of the first and second medium-voltage paths 6a, 6b respectively, which can be actuated by the control/regulation device 25. The first switches 10.1 assume the function of conventional fuses.

[0043] A second switch 10.2 is provided in the first or second medium-voltage paths 6a, 6b between the bridging path 9 of the bridge circuit 8 and the first and second battery strings 2a, 2b. In the event of a fault, these enable the medium-voltage connections 7a, 7b or the electrical consumers connected to the medium-voltage connections 7a, 7b to be disconnected from the voltage supply system 1. The two switches 10.2 on the input side of the bridge circuit 8 also enable the two voltage transformers 5a, 5b to be partially disconnected from the two battery strings 2a, 2b in the event of a fault. The switches 10.2 can also be controlled by the control/regulation device 25.

[0044] A third switch 10.3 is arranged between the first voltage transformer 5a and the first battery string 2a. A third switch 10.3 is also arranged between the second voltage transformer 5b and the first battery string 2b. The two third switches 10.3 can be integrated into the first or second voltage transformers 5a, 5b on the input side. The switches 10.3 can also be controlled by the control/regulation device 25. A fourth switch 10.4 is provided between the first voltage transformer 5a and the low-voltage connections 4. Similarly, a fourth switch 10.4 is provided between the second voltage transformer 5b and the low-voltage connections 4. The third and fourth switches 10.3, 10.4 serve to electrically isolate the respective first or second voltage transformers 5a, 5b from the voltage supply system 1.

[0045] The fourth switches 10.4 are moved to the open state if the relevant voltage transformer 5a, 5b has a defect, in particular if the voltage transformer 5a, 5b generates an electrical short circuit to earth due to a defect. So that this has no influence on the potential distributor 14, the voltage transformer is then disconnected from the potential distributor 14 on the output side. The low-voltage connections 4 are then supplied with the low voltage U.sub.NS from the remaining voltage transformer 5b, 5a.

[0046] The third switches 10.3 disconnect the relevant voltage transformer 5a, 5b from the battery strings 2a, 2b in two fault scenarios, firstly in the event of a short circuit to earth in the faulty voltage transformer 5a, 5b and secondly in the event of an imminent breakdown of the medium voltage U.sub.MS to the potential distributor 14 due to a faulty voltage transformer 5a, 5b. The third and fourth switches 10.3, 10.4 can also be controlled by the control/regulation device 25.

[0047] A fifth switch 10.5 can be provided at each of the low-voltage connections, which can act as a fuse. The switches 10.5 can also be controlled by the control/regulation device 25.

[0048] A sixth switch 10.6 is respectively provided at each of the first battery output 12a and the second battery output 12b. In the event of a fault, the two switches 10.6 enable the first or second battery strings 2a, 2b to be disconnected from the voltage supply system 1.

[0049] The voltage supply system 1 can be switched between a nominal system state, a first battery string fault state and a second battery string fault state by means of the switches 10.1 to 10.6 presented above.

[0050] In the nominal system state, the two battery strings 2a, 2b function in a fault-free manner, i.e., nominally, and both generate the electrical medium voltage U.sub.MS. Likewise, in the nominal state, the voltage transformer unit 5 generates the low voltage U.sub.NS from the medium voltage U.sub.MS.

[0051] In the nominal system state of the voltage supply system 1, the bridge circuit 8 is set in such a way that the first medium-voltage connection 7a is electrically connected to the first battery string 2a—but not to the second battery string 2b—and the second medium-voltage connection 7b is electrically connected to the second battery string 2b—but not to the first battery string 2a. In the nominal system state, the low voltage connections 4 are connected to the first battery string 2a or to the second battery string 2b or to both battery strings 2a, 2b. In the nominal system state, all switches 10.1 to 10.6 are in the closed state.

[0052] In the first battery string fault state—i.e., when a fault occurs in the first battery string 2a—the bridge circuit 8 is set accordingly such that the first and second voltage connections are both connected to the second battery string 2b, but not to the first battery string 2a. This state is activated when a fault occurs in the first battery string 2a—in particular when this cannot provide the nominal medium voltage U.sub.MS due to the fault. In the first battery string fault state, the second battery string 2b additionally assumes the function of the first battery string 2a, which means that it also provides the medium voltage U.sub.MS at the first medium voltage connection 7a. Therefore, in the first battery string fault condition, the voltage transformer unit 5 is set in such a way that the low-voltage connections 4 are connected to the second battery string 2b—but not to the first battery string 2a.

[0053] In the first battery string fault state, the first two switches 10.1, 10.3, 10.4 and 10.5 are in the closed state. The switch 10.2 assigned to the second medium voltage path 6b is in the closed state, the switch 10.2 assigned to the first medium voltage path 6a is in the open state. The switch 10.6 assigned to the second battery string 2b is in the closed state. The switch 10.6 associated with the first battery string 2a is in the open state. In this way, the low voltage U.sub.NS is provided at all low-voltage connections 4 and the medium voltage U.sub.MS is provided at both medium voltage connections 7a, 7b from the second battery string 2b, whereas the faulty second battery string 2b is electrically isolated from the voltage supply system 1.

[0054] In the second battery string fault state—i.e., when a fault occurs in the second battery string 2b—the bridge circuit 8 is set in such a way that the first and second medium voltage connections are both connected to the first battery string 2a, but not to the second battery string 2b. This state is activated when a fault occurs in the second battery string 2b—in particular when this cannot provide the nominal medium voltage U.sub.MS due to the fault. In the second battery string fault state, the first battery string 2a additionally assumes the function of the second battery string 2b, which means that it also provides the medium voltage U.sub.MS at the second medium voltage connection 7b. Therefore, in the second battery string fault state, the voltage transformer unit 5 is set in such a way that the low-voltage connections 4 are connected to the first battery string 2a—but not to the second battery string 2b.

[0055] In the second battery string fault state, the first two switches 10.1, 10.3, 10.4 and 10.5 are in the closed state. The switch 10.2 assigned to the first medium voltage path 6a is in the closed state, the switch 10.2 assigned to the second medium voltage path 6b is in the open state. The switch 10.6 associated with the first battery string 2a is in the closed state, the switch 10.6 associated with the second battery string 2b is in the open state. In this way, the low-voltage U.sub.NS is provided at all low-voltage terminals 4 and the medium voltage U.sub.MS is provided at both medium-voltage connections 7a, 7b from the first battery string 2a, whereas the faulty second battery string 2b is electrically isolated from the voltage supply system 1.

[0056] Furthermore, the voltage supply system 1 can—independently of the battery string fault states explained above—additionally have a first and second voltage transformer fault state. These two fault states can be combined with the first and second battery string fault states.

[0057] If the voltage supply system 1 is in the first voltage transformer fault state, there is a fault in the first voltage transformer 5a such that it cannot generate the low voltage U.sub.NS. In this case, the voltage transformation from the medium voltage U.sub.MS to the low voltage U.sub.NS is carried out exclusively by the second voltage transformer 5b. For this purpose, the control/regulation device 25 switches the switches 10.3 and 10.4 associated with the first voltage transformer 5a to the open state and the switches 10.3 and 10.4 associated with the second voltage transformer 5b to the closed state, starting from the nominal system state. In this way, the first voltage transformer 5a that has the malfunction is bypassed.

[0058] If the voltage supply system 1 is in the second voltage transformer fault state, there is a fault in the second voltage transformer 5b so that it cannot generate the low voltage U.sub.NS. In this case, the voltage transformation from the medium voltage U.sub.MS to the low voltage U.sub.NS takes place exclusively via the first voltage transformer 5a. For this purpose, the control/regulation device 25 switches the switches 10.3 and 10.4 associated with the second voltage transformer 5b to the open state and the switches 10.3 and 10.4 associated with the first voltage transformer 5a to the closed state, starting from the nominal system state. In this way, the second voltage transformer 5b that has the malfunction is bypassed.

[0059] Since the two voltage transformers 5a, 5b are both connected in parallel with the potential distributor 14, there is double redundancy for the low-voltage connections 4 with regard to the voltage supply, namely against the failure of a battery string 2a or 2b, as well as against the failure of a voltage transformer 5a or 5b. The low-voltage connections 4 are thus protected against the failure of a battery string 2a or 2b—regardless of which one—and separately or additionally simultaneously, the failure of a voltage transformer 5a, 5b—regardless of which one. As long as at least one battery string 2a, 2b and at least one voltage transformer remain in function, the supply of the low-voltage connections, among others, the safety-critical on-board power system control units are supplied with voltage.

[0060] The independence of the battery string fault states from the voltage transformer fault states described above—and vice-versa—implements a double redundancy in the voltage supply system 1, such that the full functionality of the voltage supply system 1 is guaranteed even in the event of simultaneous failure of one of the two voltage transformers 5a, 5b and one of the two battery strings 2a, 2b.

[0061] FIG. 2 shows a schematic depiction of an example of a battery module 30 according to the invention. This comprises a voltage supply system 1 according to the invention to each of whose low-voltage connections 4 an electrical consumer 31 is connected, such that it is supplied with a supply voltage of 12V by the voltage supply system 1. By way of example, a fan for cooling the internal combustion engine of the motor vehicle, a braking device for braking the motor vehicle, a vehicle steering device for steering the motor vehicle, and a lighting device for illuminating the interior of the motor vehicle can be considered as an electrical consumer 31.

[0062] An electrical consumer 32 is also connected to each of the two medium-voltage connections 7a, 7b in such a way that it is supplied with a supply voltage of 48V by the voltage supply system 1. In the example of the figures, the consumers 32 are a PTC heater for heating a vehicle interior of the motor vehicle, a refrigerant compressor of an air conditioning system present in the motor vehicle, and a starter generator for starting an internal combustion engine of the motor vehicle.

[0063] The battery module 30 can optionally have a third medium-voltage connection 7c—not depicted in the exemplary voltage supply system 1 of FIG. 1—to which a DC-DC transformer 33 is connected, which raises the medium voltage U.sub.MS of 48V provided at the medium-voltage connection 7c to a DC high voltage of between 600V and 700V and provides it on the output side at transformer output 34. The high voltage generated by means of the DC-DC transformer 33 can be used to drive a motor vehicle with a purely electric drive.

[0064] Although the invention has been illustrated and described in detail by way of preferred embodiments, the invention is not limited by the examples disclosed, and other variations can be derived from these by the person skilled in the art without leaving the scope of the invention. It is therefore clear that there is a plurality of possible variations. It is also clear that embodiments stated by way of example are only really examples that are not to be seen as limiting the scope, application possibilities or configuration of the invention in any way. In fact, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete manner, wherein, with the knowledge of the disclosed inventive concept, the person skilled in the art is able to undertake various changes, for example, with regard to the functioning or arrangement of individual elements stated in an exemplary embodiment without leaving the scope of the invention, which is defined by the claims and their legal equivalents, such as further explanations in the description.