CN113306410B - Redundant onboard electrical system and motor vehicle - Google Patents

Abstract

The present invention relates to a redundant onboard power system for a motor vehicle, which has a first and a second sub-onboard power system for supplying power to a first or a second drive device. Here, the first sub-onboard power system has: a first high-voltage power system; a first low-voltage power system supplied by the first high-voltage power system; and a first bus system supplied by the first high-voltage power system or the first low-voltage power system, for data transmission between components integrated into the first sub-onboard power system under normal use. Similarly, the second sub-onboard power system has: a second high-voltage power system; a second low-voltage power system; and a second bus system for data transmission between components integrated into the second sub-onboard power system under normal use. The first and second high-voltage power systems have respectively assigned first or second energy storage devices. 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 technology manner under normal use. The first and second high-voltage power systems are set up to have no feedback to each other at least during driving operation.

Description

Redundant onboard electrical system and motor vehicle

Technical Field

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

Background technique

Generally, the electrical and/or electronic infrastructure of a vehicle, especially also a motor vehicle, is understood as an onboard power system. This infrastructure is used to connect electrical consumers and in particular to supply (operating) energy to the electrical consumers. Although the onboard power system is also used in vehicles with internal combustion engines, the structure of the onboard power 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 electrical consumers, such as sensors, comfort functions, but also control devices for safety-related components (such as airbags, electronic stability systems, etc.) are supplied.

Of particular interest in electrically driven vehicles are redundancy structures which come into play in the event of a fault, for example in an energy storage device, in one of the above-mentioned electrical consumers, in the infrastructure itself or the like. Currently, efforts are being made, in particular in the field of purely electric vehicles, to enable relatively controlled coasting or stopping of the vehicle in emergency operation, for example.

For example, DE 10 2016 215 564 A1 discloses an onboard power system with two onboard power subsystems, one of which contains components that are less relevant for vehicle safety. Such components are more likely to belong to the comfort area or normal operation. These components are usually less safety-related. The purpose of selecting this division is that for emergency operation of the vehicle, the onboard power subsystem with the less safety-related components can be separated from the other onboard power subsystem and disconnected.

DE 100 33 317 A1 discloses an onboard power system having an emergency battery for safety-related electrical consumers. As long as the main battery is available for energy supply, the emergency battery is disconnected from the safety-related electrical consumers by means of a relay. If the main battery fails, the emergency battery is coupled to the safety-related electrical consumers, for example also the drive, but not to non-critical electrical consumers.

Summary of the invention

The object of the present invention is to create a vehicle system which is particularly fail-safe.

According to the invention, this object is achieved by a redundant onboard power supply system 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 onboard power system for a motor vehicle according to the present invention has a first sub-onboard power system, which is set up and arranged to supply power to a first drive device, especially integrated into the first sub-onboard power system in a normal use state of the onboard power system in a motor vehicle. The onboard power system also has a second sub-onboard power system, which is set up and arranged to supply power to a second drive device, especially integrated into the second sub-onboard power system in a normal use state of the onboard power system in a motor vehicle. Here, the first sub-onboard power system has: a first high-voltage power system; a first low-voltage power system supplied by the first high-voltage power system; and a first bus system supplied by the first high-voltage power system or the first low-voltage power system, for data transmission between components integrated into the first sub-onboard power system in a normal use state. The second sub-onboard power system has: a second high-voltage power system; a second low-voltage power system supplied by the second high-voltage power system; and a second bus system supplied by the second high-voltage power system or the second low-voltage power system, for data transmission between components integrated into the second sub-onboard power system in a normal use state. The first and second high-voltage power systems also have respectively assigned first or second energy storage devices. That is, the first high-voltage network has a first energy storage device and the second high-voltage network has a second energy storage device. In addition, for the driving operation of the motor vehicle, drive-related components and (especially also for the driving operation) safety-related components are coupled to the first and second bus systems in a data transmission technology manner in normal use. In addition, at least the first and second high-voltage networks are designed to have no feedback to each other at least during driving operation.

The first or second drive device is in particular each an electric drive, preferably an electric motor, which preferably has an associated control device and/or converter, for example a pulse-controlled inverter, a frequency converter or the like.

The term “integrated” is to be understood here and hereinafter to mean in particular that corresponding elements, for example drives and/or corresponding components, are connected (also referred to as “coupled”) to a corresponding power system in terms of energy and/or signal transmission.

In general, the redundant onboard power system according to the present invention described here and below has two onboard power systems that are basically independent of each other and independent of each other, namely the first and second sub-onboard power systems, which are respectively divided into a high-voltage power system and a low-voltage power system and have a "own" bus system. Therefore, since the allocated drive devices are respectively powered by such independent sub-onboard power systems, a high redundancy is provided. However, in order not to have to set all vehicle components in duplicate, it is preferred that many of these vehicle components continue to exist in a common way ("only"), but drive and safety-related components, such as airbag systems, steering systems, steering and driver assistance systems, anti-lock braking systems, other driving command input systems (such as accelerator pedals and brake pedals), etc., are coupled to the bus systems of the two sub-onboard power systems. As a result, energy can be saved on the one hand, but on the other hand, at least in the case of a simple fault that causes one of the two sub-onboard power systems to fail, the motor vehicle can continue to drive with only one drive device and therefore the other sub-onboard power system.

Preferably, the first drive device is set up and arranged to drive one of the plurality of axles, and the second drive device is correspondingly set up and arranged to drive another of the plurality of axles of the motor vehicle. For example, one drive device forms a rear-wheel drive and the other drive device forms a front-wheel drive. In this case, the motor vehicle using the redundant onboard power system, in particular according to the invention described in more detail below, is preferably configured as an all-wheel drive (or at least with a plurality of drive axles) motor vehicle during normal driving operation, which can continue to travel as a single-axle drive motor vehicle (i.e., for example with front-wheel drive or rear-wheel drive) when one drive device fails, for example due to a fault in one of the onboard power subsystems.

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

In a preferred embodiment, the first and second high-voltage grids are galvanically separated from each other for the purpose of preventing feedback. This effectively prevents a failure in one of the two high-voltage grids, for example a failure of the first or second energy store, from affecting the other high-voltage grid.

Preferably, the first and second bus systems are designed to have no feedback to one another, at least in normal driving conditions.

In a suitable embodiment, the first and second bus systems are coupled to the drive-related components and the safety-related components without feedback (especially galvanically separated) in normal use. This also prevents a failure in one of the two sub-onboard power systems from affecting the other sub-onboard power system across the corresponding components. These components have, for example, at least two mutually independent interfaces for the first and second bus systems (i.e., respectively assigned interfaces). Additionally or alternatively, these components are combined into one or more groups (for example within the so-called "bus level"), and the corresponding groups themselves are directed to one input of each of the two bus systems without feedback.

For example, the first and the second bus system are optically coupled for galvanic separation (if necessary directly with one another and/or with the aforementioned drive and safety-related components).

Optionally, a CAN bus is used as bus system.

In another advantageous embodiment, the first bus system is set up as a master for drive-related and safety-related components, and the second bus system is set up as a slave for drive-related and safety-related components. 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 the communication, in particular only if the first onboard power subsystem (and therefore also the first bus system) fails.

Alternatively, for a first part of the drive-related and/or safety-related components, the first bus system constitutes the master and for a respectively different second part, the first bus system constitutes the slave, wherein correspondingly, conversely, the second bus system constitutes the master for the second part and the slave for the first part.

Preferably, in addition to the two main voltage electrical systems, a first and a second low-voltage electrical system are also non-feedback-free, in particular galvanically separated from one another, at least in normal driving conditions.

In a suitable embodiment, in normal use, the control devices of the corresponding other (that is, non-safety-related) components of the first and second onboard power subsystems (or at least some of these control devices) are supplied with energy only from the first or second low-voltage power grid, respectively. In other words, these components are coupled to the corresponding low-voltage power grid for energy supply. Such components are, for example, seat heating devices, electric motors for movable vehicle parts (such as trunk lids, doors, windows, etc.), audio and media playback devices, etc.

Drive-related and safety-related components have, in particular, an element to be actuated, in the case of a steering system, for example an electric motor which generates the required steering force, and an associated control unit, in the present case a steering control unit.

In an advantageous embodiment, in normal use, the control units of the drive-related components and the safety-related components (and optionally also the components themselves) are coupled to both the first and second low-voltage power grids for energy supply. In this case, the first and second low-voltage power grids are preferably connected to the respective control units without feedback from one another, in particular galvanically separated. Thus, the components are not only redundantly connected in terms of data transmission technology, but also redundantly connected in terms of energy supply technology.

In a suitable variant, the above-mentioned control unit of the drive-related component and the safety-related component has two control devices separated from each other by current, that is, specifically, circuit logics separated from each other (that is, for example, two circuit boards each having a processor), which are arranged in a common housing or alternatively arranged in a separately assigned housing. Therefore, these control units contain redundantly implemented circuit logics. These circuit logics are in turn independent of each other and are therefore connected to one of the two bus systems or low-voltage systems in a current-separated manner. This can prevent: for example, when there is a short circuit in one of the two sub-onboard power systems, not the entire control unit for the corresponding drive-related or safety-related component is disconnected, but only the correspondingly assigned circuit logic is disconnected.

In an alternative variant, the above-mentioned control units of the drive-related and safety-related components have only one circuit logic (constituting a single control device) which is galvanically separated from the two onboard power subsystems (specifically 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 onboard power subsystems and switches to the other onboard power subsystem as quickly as possible in the event of a fault, that is, disconnects the power supply from one of the onboard power subsystems and switches on the power supply from the other onboard power subsystem.

In a suitable embodiment, in normal use, the air conditioning device (in particular the electric air conditioning compressor and/or the heater, for example the high-voltage heater) is connected only to the first onboard power subsystem for energy supply, in particular - unlike the other components described above - to the high-voltage power system. In particular, since in normal use the cooling of the two energy storage devices (and/or the assigned electric motors) is preferably also supplied by the air conditioning device, in this case the control device of the second drive device is set up to reduce the power of the second drive device in the event of a failure of the first onboard power subsystem. As a result, overheating of the second energy storage device (or the assigned electric motor) or at least relatively rapid heating can be prevented, so that the range can be kept as large as possible in the event of a failure of the first onboard power subsystem.

In an alternative embodiment, in addition to the above-mentioned air conditioning system, another air conditioning system is present in the normal use state, which is in turn (preferably only) connected to the second onboard sub-system, in particular the second high-voltage system. As a result, even if any onboard sub-system and thus its air conditioning system fails, driving can continue without a power reduction caused by cooling (that is, caused by a lack of cooling). In addition, in this case, even in emergency operation (that is, when a sub-system fails), a relatively high comfort of the passengers is possible.

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

The motor vehicle according to the invention has the above-described first and second (especially fully electric) drive units and the above-described redundant onboard power supply system. The motor vehicle therefore has the same features and advantages as the above-described onboard power supply system.

Preferably, the motor vehicle is designed as a fully autonomous motor vehicle. Particularly preferably, the motor vehicle is a robot taxi, which a user can order, for example, at a pick-up point and be taken to the destination. In this case, it is particularly advantageous to be able to travel further than the above-mentioned, common emergency operation, since this prevents a person who may be traveling alone or may have a disability from being "stuck" on a long stretch of highway or state road, for example due to a malfunction of an energy storage device or the like.

The conjunction “and/or” is to be understood here and hereinafter in particular to mean that the features linked by means of this conjunction can be configured not only together but also as an alternative to one another.

BRIEF DESCRIPTION OF THE DRAWINGS

Subsequently, the embodiments of the present invention are further described with reference to the accompanying drawings.

FIG. 1 shows a schematic side view of a motor vehicle having an onboard electrical system;

FIG2 shows a high-voltage area and a low-voltage area of an on-board power system in a schematic circuit diagram;

FIG3 shows a schematic circuit diagram of the high-voltage region of the onboard electrical system; and

FIG. 4 shows a bus area of an onboard electrical system in a schematic principle diagram.

In all the figures, parts which correspond to one another are always provided with the same reference symbols.

Detailed ways

FIG. 1 schematically shows a motor vehicle 1. The motor vehicle 1 is configured as an electric vehicle and has an onboard power system 2, which is set up and configured to provide energy. The motor vehicle 1 also has a first drive device 4 and a second drive device 6. Here, the first drive device 4 has a first drive motor 8, and the second drive device 6 correspondingly has a second drive motor 10. The two drive devices 4 and 6 also each have a pulse inverter 12 assigned to the corresponding drive motor 8 or 10 (see FIG. 3). The first drive device 4 is assigned to the rear axle of the motor vehicle 1 and correspondingly forms a rear wheel drive. Correspondingly, the second drive device 6 forms a front wheel drive.

The onboard power system 2 has a first onboard sub-power system 14 for supplying power to the first drive device 4, and has a second onboard sub-power system 16 for supplying power to the second drive device 6. The first and second onboard sub-power systems 14 and 16 are identically and independently constructed with respect to energy supply. Here, the first and second onboard sub-power systems 14 and 16 include a first or second (high-voltage) energy storage device 18 or 20, a first or second high-voltage power grid 22 or 24, and a first or second low-voltage power grid 26 or 28 downstream of these high-voltage power grids, respectively. The two low-voltage power grids 26 and 28 are coupled to the high-voltage power grids 22 or 24 respectively assigned to them by means of a DC voltage converter 30. Optionally, the two low-voltage power grids 26 and 28 also have a low-voltage energy storage device 32.

High-voltage loads 34 (also referred to as “high-voltage components”) are integrated in the high-voltage power grids 22 and 24 in an energy supply technical manner. In addition to the two drive motors 8 or 10, such high-voltage loads 34 in the first high-voltage power grid 22 according to FIG. 3 are specifically an electric air conditioning compressor 36 and a high-voltage heater 38 (e.g., a vehicle interior heating device). Low-voltage loads 40 (also referred to as “low-voltage components”) are integrated in the low-voltage power grids 26 and 28 in an energy supply technical manner. On the one hand, these low-voltage loads 40 are components that are not critical for the drive and safety of the motor vehicle 1, specifically, for example, a trunk lid drive 42 and an interior lighting 44 integrated in the first low-voltage power grid 26 in the normal use state of the onboard power system 2 in the motor vehicle 1, and a seat heating device 46 integrated in the second low-voltage power grid 28. On the other hand, these low-voltage loads 40 are also critical (or “relevant”) components for the drive and safety of the motor vehicle 1 , specifically for driving operation, specifically an electronic stability control system 48 integrated into the first low-voltage network 26 and driving lights 50 integrated into the second low-voltage network 28 .

For data transmission of the above-mentioned components, specifically to a control unit which in turn includes a control device, first onboard power subsystem 14 has a first bus system (“bus 52 ”), specifically designed as a CAN bus, and second onboard power subsystem 16 has a second bus system (“bus 54 ”), specifically likewise designed as a CAN bus.

During normal driving operation, first onboard power subsystem 14 and second onboard power subsystem 16 are electrically isolated from each other without feedback, specifically reversibly (indicated by connecting line 56 between high-voltage power systems 22 and 24 and optionally connecting line 58 between low-voltage power systems 26 and 28). If one of onboard power subsystems 14 and 16 fails, driving can still be continued with only one of the two drive devices 4 or 6. For this purpose, components critical to drive and safety are coupled to the two buses 52 and 54 in a data transmission manner, so that corresponding information can also be used and made available to the other onboard power subsystem 14 or 16, respectively.

As can be seen from FIG. 4 , the two buses 52 or 54 each have a bus control device 60 or 62 for this purpose, which forms a central computer or “gateway” and is used to route the signals of the individual “bus levels” 64 , in which components of different functional areas of the motor vehicle 1 , for example, components related to comfort functions (such as seat heating 46 and interior lighting 44 ), energy supply, drive functions (such as electronic stability system 48 ), etc., are combined. FIG. 4 shows that the corresponding control units of the components that are critical for the drive and safety are connected to the corresponding bus level 64 of the respective other bus 52 or 54 by means of additional signal lines 66. In a preferred (not further shown) embodiment, these control units each include two control devices or circuit logics, which are each connected to one of the two buses 52 or 54. In this case, the signal line 66 is coupled to the corresponding control device on the respective other bus 52 or 54 without feedback. In this way, in the event of a failure of one of onboard electrical system subsystems 14 or 16 , the respective other onboard electrical system subsystem 16 or 14 can access data relevant for the drive and safety.

The vehicle control unit (not shown in further detail) is also configured to selectively operate motor vehicle 1 with all-wheel drive, front-wheel drive or rear-wheel drive (at least depending on the availability of the two onboard electrical system subsystems 14 and 16 ).

The onboard power system 2 also has a switching device 68, which is used to connect the two high-voltage power grids 22 and 24 to an energy feed point, specifically a charging socket 70 of the motor vehicle 1, when the motor vehicle 1 is not driving. To this end, the switching device 68 controls corresponding high-voltage contactors 72.

In order to disconnect the respective energy storage device 18 or 20 in the event of a short circuit or other fault, the two high-voltage power grids 22 and 24 each have an explosion protection device 74 and at least one further protection device 76. For controlled disconnection, for example for maintenance, the two high-voltage power grids 22 and 24 have contactors 78 upstream of the energy storage devices 18 and 20.

The subject matter of the present invention is not limited to the embodiments described above. Rather, other embodiments of the present invention can be derived by those skilled in the art based on the above description.

Reference numerals list

1 Motor Vehicle

2 On-board power grid system

4 Drive device

6 Drive device

8. Drive Motor

10. Drive Motor

12-pulse inverter

14 Sub-vehicle power grid

16 Sub-vehicle power grid

18 Accumulator

20 Accumulator

22 High voltage power grid

24 High voltage power grid

26 Low voltage power grid

28 Low voltage power grid

30 DC voltage converter

32 Low pressure accumulator

34 High voltage electrical appliances

36 Air conditioning compressor

38 High pressure heater

40 Low voltage electrical appliances

42 Trunk lid drive

44 Interior space lighting

46 Seat heating equipment

48 Electronic Stability System

50 Driving lights

52 Bus

54 Bus

56 Connection line

58 Connection cable

60 Bus control device

62 Bus control device

64 Bus Level

66 signal line

68 Switching device

70 Charging socket

72 High voltage contactor

74 explosion-proof safety device

76 Safety device

78 Contactor.

Claims (11)

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.