CN113306410B

CN113306410B - Redundant on-board power system and motor vehicle

Info

Publication number: CN113306410B
Application number: CN202110215075.1A
Authority: CN
Inventors: M·施托尔茨; B·韦伯
Original assignee: Volkswagen AG
Current assignee: Volkswagen AG
Priority date: 2020-02-26
Filing date: 2021-02-26
Publication date: 2024-06-21
Anticipated expiration: 2041-02-26
Also published as: DE102020202466A1; CN113306410A

Abstract

The invention relates to a redundant on-board power system for a motor vehicle, comprising a first and a second sub-on-board power system for supplying a corresponding power to a first or a second drive. The first sub-electrical system has: a first high voltage power grid; a first low voltage power grid powered by the first high voltage power grid; and a first bus system powered by the first high-voltage power network or the first low-voltage power network for data transmission between components integrated into the first sub-vehicle power network in normal use. Similarly thereto, the second sub-vehicle electrical system has: a second high voltage power grid; a second low voltage power grid; and a second bus system for data transmission between components integrated into the second sub-vehicle electrical system in normal use. The first and second high-voltage networks have first or second accumulators respectively assigned. For the driving operation of the motor vehicle, the drive-related components and the safety-related components are coupled to the first and second bus systems in a data transmission manner in normal use. The first and the second high-voltage network are designed to have no feedback from each other at least during driving operation.

Description

Redundant on-board power system and motor vehicle

Technical Field

The invention relates to a redundant vehicle-mounted power system. The invention also relates to a motor vehicle having such a redundant on-board electrical system.

Background

In general, the electrical and/or electronic infrastructure of a vehicle, in particular also a motor vehicle, is understood to be the on-board electrical system. The infrastructure is used for coupling the consumers and in particular for supplying (operating) the consumers with energy. Although the on-board electrical system is also used in vehicles with internal combustion engines, the construction of the on-board electrical system is relatively complex in electrically driven vehicles. In this case, there are usually at least two different voltage levels, namely a high voltage level from which the traction motor is supplied, in particular, and a low voltage level from which other consumers, for example control devices for sensors, comfort functions, but also for safety-relevant components (for example airbags, electronic stability systems, etc.), are supplied.

Of particular interest in electrically driven vehicles is the redundant structure that functions when a fault occurs, for example, in an accumulator, in one of the above-mentioned consumers, in the infrastructure itself or the like. Currently, in particular in the field of purely electric vehicles, for example, efforts are made to enable relatively controlled coasting or parking of the vehicle in emergency operation.

DE 10 2016 215 564 A1 discloses, for example, an on-board power system having two sub-on-board power systems, one of which contains components that are not so relevant for vehicle safety. Such assemblies are more likely to fall into the comfort field or normal operation. These components are generally less security-relevant. The purpose of this division is to select: for emergency operation of the vehicle, the sub-onboard power system with less safety-relevant components can be separated from the other sub-onboard power system and disconnected.

DE 100,33,317 A1 discloses an on-board power system having an emergency battery for safety-relevant consumers. As long as the main battery is present for energy supply, the emergency battery is separated from the safety-relevant consumers by a relay. If the main battery fails, the emergency battery is coupled to these safety-relevant consumers, for example also to the drive, but not to non-critical consumers.

Disclosure of Invention

The invention is based on the task of: a particularly fail-safe vehicle system is achieved.

According to the invention, this object is achieved by a redundant electrical system for a vehicle according to the invention. According to the invention, this object is also achieved by a motor vehicle according to the invention. Advantageous and partly inventive embodiments and developments are explained in the following description.

The redundant electrical system for a motor vehicle according to the invention has a first sub-electrical system which is designed and provided for supplying power to a first drive, in particular integrated into the first sub-electrical system in the normal use state of the electrical system in the motor vehicle. The on-board electrical system further has a second sub-on-board electrical system which is designed and provided for supplying the second drive, in particular integrated into the second sub-on-board electrical system in the normal use state of the on-board electrical system in the motor vehicle. The first sub-electrical system has: a first high voltage power grid; a first low voltage power grid powered by the first high voltage power grid; and a first bus system powered by the first high-voltage power network or the first low-voltage power network for data transmission between components integrated into the first sub-vehicle power network in normal use. The second sub-vehicle electrical system has: a second high voltage power grid; a second low voltage power grid powered by the second high voltage power grid; and a second bus system powered by the second high-voltage power supply system or the second low-voltage power supply system for data transmission between components integrated into the second sub-vehicle power supply system in a normal use state. The first and second high-voltage networks also have a first or second energy store respectively assigned. That is to say that the first high-voltage network has a first energy store and the second high-voltage network has a second energy store. Furthermore, the drive-related components for driving operation of the motor vehicle and, in particular, the safety-related components for driving operation as well, are coupled to the first and second bus systems in a data transmission manner in normal use. Furthermore, at least the first and the second high-voltage network are designed to be feedback-free from one another at least during operation.

The first or the second drive is in particular an electric drive, preferably an electric motor, which preferably has associated control devices and/or converters, for example pulse inverters, frequency converters or the like.

The term "integrated" is understood here and below in particular as: the corresponding components, for example the drive and/or the corresponding components, are connected (also referred to as "coupled") to the corresponding power supply system in an energy and/or signal transmission manner.

In general, the redundant on-board power system according to the invention described here and below has two on-board power systems, i.e. a first and a second sub-on-board power system, which are substantially independent of one another and independent of one another, which in turn are each divided into a high-voltage power system and a low-voltage power system and have an "own" bus system. Thus, a high redundancy is provided, since the assigned drives are each supplied by such an independent sub-vehicle electrical system. However, in order not to have to provide all vehicle components in the same double way, it is preferable that many of these vehicle components continue to be present singly in the usual manner ("only"), but that drive-and safety-relevant components, such as for example airbag systems, steering and driver assistance systems, antilock systems, other driving command input systems (for example accelerator pedal and brake pedal) etc., are coupled to the bus system of the two sub-vehicle electrical systems. In this way, energy can be saved on the one hand, but on the other hand, in the event of a simple failure, which leads to a failure of one of the two sub-electrical systems, the motor vehicle can continue to travel with only one drive and thus the other sub-electrical system.

Preferably, the first drive is set up and arranged for driving one of the plurality of drive shafts, and the second drive is correspondingly set up and arranged for driving another of the plurality of drive shafts of the motor vehicle. For example, one driving device constitutes a rear wheel drive, and the other driving device constitutes a front wheel drive. In this case, the motor vehicle, in particular the motor vehicle according to the invention described in more detail below, is preferably configured as an all-wheel-drive motor vehicle (or at least has a plurality of drive axles) during normal driving operation, which motor vehicle can continue to drive as a single-shaft-drive motor vehicle (i.e. for example with front-wheel drive or rear-wheel drive) if there is a failure of one of the drive units, for example due to a fault in one of the sub-vehicle systems.

In this way, in particular, in comparison with the emergency operation of the known solutions, which is often only possible for relatively controlled coasting and/or stopping of the motor vehicle at the roadside or the like, even in the event of failure of one of these drives (except that a multi-axis drive is no longer possible), an almost normal continued travel can be achieved, for example until the next repair shop or the like. This is particularly advantageous for fully autonomous vehicles, since in this case anchors on relatively long highways or road sections can be avoided.

In a preferred embodiment, the first and second high-voltage networks are galvanically separated from each other for feedback-free. Thereby, a failure in one of the two high-voltage networks, for example a failure of the first or second energy store, is effectively prevented from affecting the other high-voltage network.

Preferably, the first and second bus systems are set up so that they do not feed back to each other at least in the normal driving state.

In a suitable embodiment, the first and second bus systems are coupled without feedback (in particular galvanically separated) to the drive-related components and to the safety-related components in normal use conditions. In this way, a failure in one of the two sub-electrical systems is likewise prevented from affecting the other sub-electrical system across the respective component. These components have, for example, at least two interfaces (i.e., respectively assigned interfaces) for the first and second bus systems that are independent of one another. In addition or alternatively, the components are combined into one or more groups (for example within a so-called "bus plane") and the respective groups are themselves fed back to a respective one of the inputs of one of the two bus systems.

For example, the first and the second bus system are optically coupled for galvanic separation (if necessary directly from each other and/or from the above-described drive-and safety-related components).

Alternatively, a CAN bus is used as the bus system.

In a further advantageous embodiment, the first bus system is set up as a master for driving the relevant component and the safety-relevant component, and the second bus system is set up as a slave for driving the relevant component and the safety-relevant component. In this case, the first bus system communicates with these components during normal driving operation (also referred to as "normal state"), while the second bus system takes over this communication, in particular only if the first sub-onboard power supply system (and thus also the first bus system) fails.

Alternatively, the first bus system forms a master for a first part of the drive-related component and/or the safety-related component, and forms a slave for the respective other second part, wherein the second bus system correspondingly forms a master for the second part and a slave for the first part.

Preferably, in addition to the two main voltage grids, the first and second low voltage grids are also feedback-free from each other, in particular galvanically separated from each other, at least in normal driving conditions.

In a suitable embodiment, in normal use, the control devices (or at least some of them) of the respective other (that is to say non-safety-relevant) components of the first and second sub-onboard electrical systems are supplied with energy only by the first or second low-voltage electrical system, respectively. In other words, for energy supply, these components are coupled with a corresponding electrical power grid. Such components are, for example, seat heating devices, motors for movable vehicle parts (e.g., trunk lids, doors, windows, etc.), audio and media playback devices, etc.

The drive-related component and the safety-related component have, in particular: the element to be actuated, in the case of a steering system, is, for example, an electric motor which generates the required steering force; and an assigned control unit (steering control unit in the present case).

In an advantageous embodiment, the control unit driving the relevant components and the safety relevant components (and optionally also the components themselves) is coupled for energy supply to both the first and the second low voltage network in normal use conditions. In this case, the first and the second power supply system are expediently connected to the respective control unit without feedback, in particular galvanically separated from each other. These components are therefore not only connected redundantly in terms of data transmission technology, but also in terms of energy supply technology.

In one suitable variant, the above-mentioned control unit of the drive-related component and the safety-related component has two control devices that are galvanically separated from one another, i.e. in particular circuit logic that are separated from one another (i.e. for example two circuit boards each having a processor), which are arranged in a common housing or alternatively in separately assigned housings. Thus, these control units contain circuit logic that is implemented redundantly. The circuit logics are in turn independent of one another and are therefore connected to a respective one of the two bus systems or low-voltage systems in a galvanically separated manner. Thereby, it is possible to prevent: for example, if there is a short circuit in one of the two sub-electrical systems, the entire control unit for the respective drive-related or safety-related component is not switched off, but only the correspondingly assigned circuit logic is switched off.

In an alternative variant, the above-mentioned control unit of the drive-related component and the safety-related component has only one circuit logic (which forms the sole control device), which is galvanically connected separately from the two sub-onboard electrical systems (in particular the two bus systems and the low-voltage system). In this case, the circuit logic preferably also includes a fault detection, which detects a fault on one of the two sub-vehicle electrical systems and switches over to the other sub-vehicle electrical system as little delay as possible in the event of a fault, that is to say cuts off the supply from one of the sub-vehicle electrical systems and switches on the supply from the other sub-vehicle electrical system.

In a suitable embodiment, in normal use conditions, the air conditioning device (in particular the electric air conditioning compressor and/or the heater, for example the high-voltage heater) is coupled for energy supply only to the first sub-onboard electrical system, in particular-unlike the other components described above-to the high-voltage electrical system. In particular, since the cooling of the two energy storages (and/or the associated electric motor) is preferably likewise supplied by the air conditioning system in the normal operating state, the control system of the second drive is designed in this case to reduce the power of the second drive in the event of a failure of the first sub-vehicle electrical system. In this way, overheating or at least a comparatively rapid heating of the second energy store (or of the associated electric motor) can be prevented, so that the voyage in the event of a failure of the first sub-vehicle electrical system can be kept as large as possible.

In an alternative embodiment, in addition to the above-mentioned air conditioning device, a further air conditioning device is present which is in turn (preferably exclusively) coupled to the second sub-onboard electrical system, in particular the second high-voltage electrical system, in the normal use state. In this way, in the event of a failure of whichever sub-vehicle electrical system, and therefore its air conditioning system, the vehicle can continue to run even without a reduction in power due to cooling (i.e. due to lack of cooling). In this case, moreover, a comparatively high comfort of the member is possible even in emergency operation (i.e. in the event of a failure of the sub-onboard electrical system).

Preferably, the respective electrical power network is coupled to the high-voltage electrical power network by means of a direct-current voltage converter (also referred to as "DC-DC converter"). For example, the corresponding high voltage power network has a rated voltage value of 400 or 800 volts, and the corresponding low voltage power network has a rated voltage value of 12, 24 or 48 volts.

The motor vehicle according to the invention has the first and second (in particular all-electric) drive described above and the redundant on-board electrical system described above. The motor vehicle thus has the same features and advantages as the onboard electrical system described above.

Preferably, the motor vehicle is configured as a completely autonomous motor vehicle. Particularly preferably, the motor vehicle is a robotic taxi, which the user can reserve, for example, to a pick-up point and be carried to the destination. In this case, it is particularly advantageous that: a further travel beyond the above-mentioned, usual emergency operation is possible, since this prevents a possibly individually traveling, possibly disabled person from "stopping" on a long highway or state road section, for example, due to a failure of an energy store or the like.

The term "and/or" is understood here and in the following in particular to mean that the features which are associated by means of the term can be configured both jointly and alternatively to one another.

Drawings

Embodiments of the present invention are further described below with reference to the accompanying drawings. Wherein:

fig. 1 shows a schematic side view of a motor vehicle with an on-board electrical system;

fig. 2 shows a schematic circuit diagram of a high-voltage region and a low-voltage region of the on-board power system;

fig. 3 shows a schematic circuit diagram of a high-voltage region of the on-board electrical system; and

Fig. 4 shows a schematic diagram of a bus area of the on-board system.

In all the figures, parts corresponding to each other are provided with the same reference numerals throughout.

Detailed Description

Fig. 1 schematically shows a motor vehicle 1. The motor vehicle 1 is configured as an electric vehicle and has an onboard electrical system 2 which is set up and provided for supplying energy. The motor vehicle 1 further has a first drive 4 and a second drive 6. The first drive 4 has a first drive motor 8, and the second drive 6 has a second drive motor 10. The two drives 4 and 6 each also have a pulse inverter 12 (see fig. 3) assigned to the corresponding drive motor 8 or 10. The first drive 4 is assigned to the rear axle of the motor vehicle 1 and forms a rear wheel drive accordingly. Correspondingly, the second drive means 6 constitute a front wheel drive.

The on-board electrical system 2 has a first sub-on-board electrical system 14 for supplying power to the first drive 4 and a second sub-on-board electrical system 16 for supplying power to the second drive 6. The first and second sub-onboard electrical systems 14 and 16 are identical in terms of energy supply and are configured independently. The first and second sub-vehicle electrical systems 14 and 16 here comprise a first or second (high-voltage) energy store 18 or 20, a first or second high-voltage electrical system 22 or 24 and a first or second low-voltage electrical system 26 or 28 downstream of these high-voltage electrical systems, respectively. The two voltage networks 26 and 28 are each coupled by means of a dc voltage converter 30 to the high voltage network 22 or 24 respectively assigned to them. Optionally, both electrical networks 26 and 28 also have a low pressure accumulator 32.

A high-voltage consumer 34 (also referred to as a "high-voltage component") is integrated in the high-voltage networks 22 and 24 in the form of an energy supply technology. In addition to the two drive motors 8 and 10, the high-voltage consumers 34 according to fig. 3 in the first high-voltage network 22 are in particular an electric air-conditioning compressor 36 and a high-voltage heater 38 (for example an in-vehicle heating system). A low-voltage consumer 40 (also referred to as a "low-voltage component") is integrated in the energy supply technology in the low-voltage networks 26 and 28. On the one hand, these low-voltage consumers 40 are components which are not critical for the drive and safety of the motor vehicle 1, in particular, for example, a trunk lid drive 42 and interior lighting 44 which are integrated in the first low-voltage network 26 in the normal use state of the on-board electrical system 2 in the motor vehicle 1, and a seat heating device 46 which is integrated in the second low-voltage network 28. On the other hand, these low-voltage consumers 40 are also components critical (or "relevant") for the drive and safety of the motor vehicle 1, in particular for the driving operation, in particular an electronic stabilization system 48 integrated into the first low-voltage network 26 and a driving light 50 integrated into the second low-voltage network 28.

For the data transmission of the components, in particular of the components, to the control unit, which in turn comprises the control device, the first sub-electrical system 14 has a first bus system ("bus 52"), in particular a CAN bus, and the second sub-electrical system 16 has a second bus system ("bus 54"), in particular also a CAN bus.

During normal driving operation, first and second sub-vehicle electrical systems 14 and 16 are galvanically separated from one another without feedback, in particular reversibly (represented by connection 56 between high-voltage electrical networks 22 and 24 and, optionally, connection 58 between electrical networks 26 and 28). If one of the sub-vehicle electrical systems 14 and 16 fails, the vehicle can still continue to travel with only one of the two drives 4 or 6. For this purpose, components critical for drive and safety are coupled to the two buses 52 and 54 in a data transmission technology, so that corresponding information can also be used and is available to the respective further sub-vehicle electrical system 14 or 16.

As can be seen from fig. 4, the two buses 52 and 54 each have a bus control device 60 and 62, respectively, which forms a central computer or "gateway" and serves to route signals of the individual "bus levels" 64, in which components of the different functional areas of the motor vehicle 1, for example components associated with comfort functions (for example, the seat heating device 46 and the interior illumination 44), energy supply, drive functions (for example, the electronic stability system 48) and the like are combined. Shown in fig. 4: the corresponding control units of the components critical for operation and safety are connected by means of additional signal lines 66 to the corresponding bus level 64 of the respective further bus 52 or 54. In a preferred embodiment (not further shown), the control units each comprise two control devices or circuit logic, which are each wired to one of the two buses 52 or 54. The signal line 66 is coupled without feedback to the corresponding control device on the respective further bus 52 or 54. In this way, in the event of a failure of one of the sub-onboard electrical systems 14 or 16, the other sub-onboard electrical system 16 or 14, respectively, can use data relating to the drive and safety.

The vehicle control device, not shown further, is also set up to: the motor vehicle 1 is selectively operated (at least as a function of the availability of the two sub-vehicle electrical systems 14 and 16) in all-wheel drive, front-wheel drive or rear-wheel drive.

The on-board electrical system 2 further has a switching device 68 for connecting the two high-voltage electrical networks 22 and 24 to an energy supply point, in particular a charging socket 70 of the motor vehicle 1 in the charging mode in which the motor vehicle 1 is not running. For this purpose, the switching device 68 actuates the corresponding high-voltage contactor 72.

In order to separate the respective energy store 18 or 20 in the event of a short circuit or other fault, the two high-voltage networks 22 and 24 each have an explosion-proof safety device 74 and at least one further safety device 76. For controlled separation, for example for maintenance, the two high-voltage networks 22 and 24 have contactors 78 upstream of the accumulators 18 and 20.

The subject matter of the present invention is not limited to the embodiments described hereinabove. Rather, other embodiments of the invention may be derived by those skilled in the art from the foregoing description.

List of reference numerals

1. Motor vehicle

2. Vehicle-mounted electric system

4. Driving device

6. Driving device

8. Driving motor

10. Driving motor

12. Pulse inverter

14. Sub-vehicle electrical system

16. Sub-vehicle electrical system

18. Energy accumulator

20. Energy accumulator

22. High-voltage power grid

24. High-voltage power grid

26. Low-voltage power network

28. Low-voltage power network

30. DC voltage converter

32. Low-pressure accumulator

34. High-voltage electric consumer

36. Air conditioner compressor

38. High-pressure heater

40. Low-voltage electric consumer

42. Trunk lid drive

44. Interior space illumination

46. Seat heating apparatus

48. Electronic stabilization system

50. Driving lamp

52. Bus line

54. Bus line

56. Connecting wire

58. Connecting wire

60. Bus control device

62. Bus control device

64. Bus layer

66. Signal line

68. Switching device

70. Charging socket

72. High-voltage contactor

74. Explosion-proof safety device

76. Safety device

78. A contactor.

Claims

1. A redundant on-board electrical system (2) for a motor vehicle (1), having:

A first sub-onboard electrical system (14) for supplying power to the first drive (4) and a second sub-onboard electrical system (16) for supplying power to the second drive (6), wherein

-The first sub-onboard electrical system (14) has: a first high voltage network (22); -a first high voltage network (26) powered by said first high voltage network (22); and a first bus system (52) supplied by the first high-voltage power network (22) or the first low-voltage power network (26) for data transmission between components (34, 40) integrated into the first sub-vehicle electrical system (14) in normal use,

-The second sub-onboard electrical system (16) has: a second high voltage grid (24); -a second electric power grid (28) powered by said second high-voltage electric power grid (24); and a second bus system (54) supplied by the second high-voltage network (24) or the second low-voltage network (28) for data transmission between components (34, 40) integrated into the second sub-vehicle electrical system (16) in normal use,

The first high-voltage network (22) has an associated first energy store (18) and the second high-voltage network (24) has an associated second energy store (20),

-A drive-related component (48) and a safety-related component (50) are coupled to the first and second bus systems (52, 54) in a data transmission manner in normal use conditions for the driving operation of the motor vehicle (1), and

The first and second high-voltage networks (22, 24) are designed to be feedback-free from one another at least during driving operation,

Wherein the first and second bus systems (52, 54) are coupled without feedback to the drive-related component (48) and to the safety-related component (50) under normal use conditions.

2. The redundant onboard electrical system (2) according to claim 1,

Wherein the first and second high voltage networks (22, 24) are galvanically separated for feedback-free.

3. The redundant onboard electrical system (2) according to any one of claims 1 to2,

Wherein the first bus system (52) is set up as a master for the drive-related component (48) and the safety-related component (50), and the second bus system (54) is set up as a slave for the drive-related component (48) and the safety-related component (50).

4. The redundant onboard electrical system (2) according to claim 1 or 2,

Wherein in normal use, the control devices of the respective other components of the first and second sub-onboard electrical systems (14, 16) are supplied with energy only by the first or second low-voltage electrical systems (26, 28), respectively.

5. The redundant onboard electrical system (2) according to claim 1 or 2,

Wherein in normal use the control unit of the drive-related component (48) and the safety-related component (50) is coupled for energy supply to both the first and the second low-voltage network (26, 28), wherein the first and the second low-voltage network (26, 28) are coupled to each other without feedback to the respective control device.

6. The redundant onboard power system (2) of claim 5,

Wherein the first and second low-voltage networks (26, 28) are galvanically separated from each other and coupled to the respective control devices.

7. The redundant onboard electrical system (2) according to claim 1 or 2,

Wherein in normal use, an air conditioning device (36) is coupled for energy supply only to the first sub-vehicle electrical system (14), and wherein the control device of the second drive device (6) is designed to reduce the power of the second drive device (6) in the event of a failure of the first sub-vehicle electrical system (14).

8. The redundant onboard electrical system (2) according to claim 1 or 2,

In which, in the normal use state, for the energy supply, an air-conditioning device (36) is coupled only to the first sub-vehicle electrical system (14) and another air-conditioning device is coupled only to the second sub-vehicle electrical system (16).

9. Motor vehicle (1) having an all-electric first drive and an all-electric second drive and having a redundant on-board electrical system (2) according to any one of claims 1 to 8.

10. Motor vehicle (1) according to claim 9, which is configured as a completely autonomous motor vehicle.

11. Motor vehicle (1) according to claim 10, wherein the fully autonomous motor vehicle is configured as a robotic taxi.