On-board electrical system layout and vehicle

Abstract

On-board electrical system arrangement (2) comprising at least one primary on-board electrical system (4) and one secondary on-board electrical system (5) for supplying a plurality of consumers (10.n) in a vehicle (1), characterized by the fact that the primary electrical system (4) for providing primary power (4.11) for supplying consumers (10.n) can be coupled to an electrical system battery (3) or is coupled and the secondary on-board network (5) is coupled to the on-board network battery (3) to provide a secondary power supply (5.11) for the redundant supply of a part (11.nm) of the consumers (10.n). wherein a switchable balancing device (8) is arranged between the primary electrical system (4) and the secondary electrical system (5), which couples or keeps coupled or decouples or keeps decoupled the primary electrical system (4) and the secondary electrical system (5) depending on the power supply, wherein in normal operation (100) of primary on-board network (4) and secondary on-board network (5) the balancing device (8) is open in order to decouple the primary on-board network (4) and the secondary on-board network (5) from each other, wherein in the coupled state of primary on-board network (4) and secondary on-board network (5) a current regulator for providing the primary power (4.11) is provided in the primary on-board network (4) as a regulator (20) and a voltage regulator for providing the secondary power (5.11) is provided in the secondary on-board network (5) and in the uncoupled state both in the primary on-board network (4) and in the secondary on-board network (5) a voltage regulator for providing the primary power (4.11) and the secondary power (5.11) is provided as a regulator (20, 22).

Description

[0001] The invention relates to an on-board electrical system arrangement having the features of the preamble of claim 1 and a vehicle with such an on-board electrical system arrangement.

[0002] On-board electrical systems for vehicles, especially motor vehicles, are generally known. Motor vehicles, particularly hybrid vehicles with an internal combustion engine and an electric motor, or purely electric vehicles with a high-voltage battery, typically comprise a primary electrical system to provide a first voltage to supply a plurality of consumers and a secondary electrical system to provide a second voltage, different from the first voltage, to supply the consumers.

[0003] From DE 10 2013 221 972 A1, such an on-board power supply arrangement with two on-board power supplies is known, which are galvanically coupled to each other via a switch in order to isolate these on-board power supplies from each other, for example in fault situations, in particular in the event of a voltage drop in one of the on-board power supplies. Further on-board power supply arrangements with two on-board power supplies and corresponding controls for these are known from DE 10 2022 001 268 A1 and DE 10 2021 118 869 A1.

[0004] The invention is based on the objective of providing an improved on-board electrical system arrangement with regard to safety and normal operation. Furthermore, a vehicle with such an improved on-board electrical system arrangement is to be provided.

[0005] The first problem is solved according to the invention by a vehicle electrical system arrangement with the features of claim 1. The second problem is solved according to the invention by a vehicle with the features of claim 10.

[0006] Advantageous embodiments of the invention are the subject of the dependent claims.

[0007] The on-board electrical system arrangement according to the invention comprises at least one primary on-board electrical system and one, in particular independent, secondary on-board electrical system for supplying a plurality of consumers in a vehicle, wherein the primary on-board electrical system can be coupled or is coupled to an on-board electrical system battery designed as a high-voltage battery for providing primary power to supply the consumers, and the secondary on-board electrical system is coupled to the on-board electrical system battery for providing secondary power for the redundant supply of some of the consumers, wherein a switchable balancing device is arranged between the primary on-board electrical system and the secondary on-board electrical system, which, depending on the power demand, couples or keeps the primary on-board electrical system and the secondary on-board electrical system to each other or decouples or keeps them decoupled from each other, and wherein, in normal operation of the primary on-board electrical system and the secondary on-board electrical system, the balancing device is open in order to decouple the primary on-board electrical system and the secondary on-board electrical system from each other.wherein, in the coupled state of the primary and secondary electrical systems, a current regulator is provided in the primary electrical system to supply the primary power, and in the uncoupled state, a voltage regulator is provided in both the primary and secondary electrical systems to supply the primary and secondary power, respectively.

[0008] In the following, the term "on-board battery" refers to a high-voltage battery. Additionally, partial on-board batteries, particularly low-voltage batteries, may be provided in the partial on-board networks, such as the primary and / or secondary on-board networks, and / or buffer batteries.

[0009] By forcing a current limit in the primary electrical system in combination with the voltage regulator in the secondary electrical system in a coupled state, a parallel connection of two electrical systems (channels) can be achieved in a coupled electrical system arrangement. In particular, oscillations of the two, potentially opposing, control systems can be reduced or even avoided. This enables stable and safe operation of the electrical system arrangement.

[0010] In other words, during normal operation of the electrical system, when the primary power supplied by the primary electrical system exceeds the power required by all currently active consumers, the balancing device is open to decouple or keep decoupled the primary and secondary electrical systems. The primary electrical system then supplies all active consumers, particularly all active comfort consumers and all active safety consumers. No power balancing takes place between the two electrical systems (also called sub-systems), and voltage regulation occurs in both sub-systems.

[0011] The advantages achieved with the invention lie particularly in the fact that, during normal operation, the primary and secondary electrical systems independently supply both comfort consumers and safety consumers with redundancy requirements. Such an electrical system arrangement with two independent electrical systems (also called electrical system channels) can meet the requirements and overall integrity of the so-called ASIL classification (according to ISO 26262). The invention is based on the consideration that if both electrical systems are operated in a coupled state, transitions in their control systems can occur, leading to unwanted control oscillations.

[0012] For example, if the primary and secondary electrical systems are decoupled during normal operation and a momentary dynamic power demand from the consumers exceeds the available power in the primary system, the voltage regulator in the primary system may not be able to adjust quickly enough, and voltage regulation may not be maintained, potentially leading to undersupply. To prevent this, the balancing device is power-dependent and can be switched to act as a controllable energy interface. This allows dynamic power demands to be met more quickly and reliably than before by utilizing the voltage-controlled, available dynamic buffer power of the secondary system in the current-controlled primary system. Specifically, if such undersupply is identified in the primary system, it switches to current-controlled operation.This transition is recorded as an indicator of the need for coupling and is used for coupling.

[0013] The primary electrical system (also called the first electrical system or first electrical system channel) is the main electrical system that supplies both comfort and safety consumers with power, especially direct current, from the vehicle's battery. The secondary electrical system (also called the second electrical system or second electrical system channel) is a safety electrical system that supplies only the safety consumers with redundancy requirements with power, especially direct current, from the vehicle's battery.

[0014] For the primary power supply of consumers, especially all comfort and safety consumers in the vehicle, the primary electrical system can be coupled to a buffer battery in addition to the vehicle battery. The buffer battery is, for example, a conventional low-voltage battery. In an emergency, the primary electrical system can be disconnected from the vehicle battery by means of a safety contactor. The primary electrical system is designed to provide a defined static primary power supply and, via the buffer battery, a dynamic buffer power supply.

[0015] For the secondary (also redundant) power supply of safety-related devices, the secondary electrical system can be directly connected to the vehicle's battery. Such a direct connection of the secondary electrical system ensures the continued power supply to safety-related devices, particularly those with redundancy requirements, even in the event of a fault in the primary electrical system and a disconnection of the primary electrical system from the battery. The secondary electrical system is designed to provide a defined, continuous static secondary power supply. In addition, the secondary electrical system is designed to provide a dynamic buffer power supply in addition to the static secondary power supply, for example, to handle short-term high current demands on the primary electrical system due to steering or braking maneuvers, allowing for the flexible supply of higher dynamic power levels.

[0016] The term battery refers in particular to a rechargeable galvanic cell (also called accumulator).

[0017] One possible embodiment provides that the primary electrical system includes a primary DC / DC converter for supplying primary power. This converter is connected to the vehicle battery on its input side and to the loads on its output side. The converter acts as a regulator, comprising a subordinate current regulator and a superordinate voltage regulator, which provides a base load current at the output corresponding to a base load or a static power requirement of the loads. The term "loads" refers in particular to all loads connected to the primary battery in the primary electrical system, for example, all comfort loads such as seat heating, interior lighting, and the like, and all safety loads such as safety assistance systems, in particular brake assist systems, steering assist systems, and the like.

[0018] The secondary electrical system can include a secondary DC / DC converter to provide secondary power. This converter is connected on the input side to the vehicle battery and on the output side to some of the loads, particularly all safety devices, for redundant power supply. For example, the electrical system configuration can include a dedicated DC / DC converter, specifically a current converter (e.g., a DC-DC converter), which is connected in series with the loads to be supplied. Alternatively, a voltage converter can be provided for each electrical system, which is connected in parallel with the loads to be supplied. The secondary DC / DC converter can also include a subordinate current regulator and a superordinate voltage regulator.

[0019] To optimize the on-board power supply arrangement, in particular to save on a third on-board power supply or on-board power supply channel and / or additional buffer batteries, the primary DC converter and / or the secondary DC converter are set up to provide a dynamic buffer power in addition to providing the primary power or the secondary power respectively.

[0020] For example, the primary DC converter and the secondary DC converter are designed identically with regard to voltage conversion, whereby they convert the same DC voltage from the vehicle battery at the input into an equally high lower DC voltage at the output, for example a battery input voltage of 800 V at the input into a respective vehicle electrical system voltage (primary electrical system voltage and secondary electrical system voltage) of, for example, 10 V to 18 V at the output.

[0021] With regard to their performance, availability, and / or dynamics, the primary and secondary converters may preferably be designed differently. In particular, the primary output power available at the primary converter is designed to be greater than the secondary output power at the secondary converter. The primary and secondary output powers represent operating parameters of the primary and secondary converters, and in particular, the maximum output powers that can be provided at the primary and secondary converters, respectively.

[0022] Regarding dynamics, the secondary DC-DC converter for providing secondary power to safety-critical devices must be designed with high dynamics, particularly with a dynamic range in the microsecond range (e.g., 100 µs). In contrast, the primary DC-DC converter can be designed with lower dynamics, for example, in the millisecond range (e.g., 1 ms or 10 ms).

[0023] Regarding availability, the secondary DC-DC converter for providing secondary power to safety-critical loads must be designed for high availability; in particular, the secondary DC-DC converter is directly connected to the vehicle's electrical system battery to supply these loads even in the event of a fault. In contrast, the primary DC-DC converter is indirectly connected to the vehicle's electrical system battery via a safety switch, specifically a safety contactor, which, in the event of a fault, such as an overload in the vehicle's electrical system, particularly in the high-voltage system (e.g., the primary electrical system), or similar, disconnects this system from the vehicle's electrical system battery.

[0024] The underlying principle of this different design of the primary and secondary DC-DC converters is that safety-critical components, such as a steering assist system or a brake assist system, which are supplied at least by the secondary DC-DC converter, require highly dynamic and highly available power supplies with high current peaks only briefly, for example, during a strong steering input and / or a strong braking input. In contrast, comfort-critical components, such as seat heating, can be supplied with low current continuously, possibly with a delay. These short load peaks for the safety-critical components result in a sufficiently large dynamic secondary buffer capacity of the secondary DC-DC converter during normal operation when no safety-critical components are active.According to a further development of the invention, this correspondingly large dynamic secondary buffer power in the secondary on-board network is used to supply the consumers in the primary on-board network.

[0025] In other words, the available dynamic buffer power, preferably that in the secondary electrical system, can be used by means of the balancing device, in particular as a buffer for dynamic processes, especially required load peaks such as current peaks and thus power peaks, in the other electrical system, especially the primary electrical system. Furthermore, the balancing device and its electrical interaction with the primary DC-DC converter and the secondary DC-DC converter ensure that when the available dynamic secondary buffer power of the secondary electrical system is used, more consumers with comfort functions can be activated or remain activated in the primary electrical system.

[0026] Both the primary and secondary electrical systems can therefore be configured to supply consumers with static and / or dynamic power.

[0027] During operation of the vehicle electrical system, depending on the number of active consumers in the respective vehicle electrical system, a currently available dynamic primary buffer power and a currently available dynamic secondary buffer power can result if the current power consumption of all active consumers in the primary vehicle electrical system or in the secondary vehicle electrical system is less than a maximum possible primary output power or a maximum possible secondary output power.

[0028] The invention enables an intelligent connection of the two separate vehicle electrical systems (also called vehicle electrical system channels, consumer electrical systems, LV electrical system channels or load consumer electrical system channels) in order to utilize the vehicle electrical system battery and, in interaction with the two DC converters (primary DC converter and secondary DC converter), in particular their available dynamic buffer capacities, and optionally the buffer battery as efficiently as possible, thus avoiding an increase in the size of the vehicle electrical system battery, the DC converters and / or the buffer battery.

[0029] Furthermore, by means of on-board network management software, which is implemented, for example, in the compensation device and / or a battery control unit (not shown), independence of the on-board networks and a safe, in particular redundant, supply of safety-relevant consumers, especially safety-relevant systems (also called ASIL systems (with ASIL = Automotive Safety Integrity Level)), such as braking systems, steering systems, steer-by-wire systems, brake-by-wire systems and / or ADAS systems, is made possible.

[0030] For example, if many loads are activated in the primary electrical system or a first electrical system channel, and only a few in the secondary electrical system or a second electrical system channel, the balancing device can support the primary electrical system (also called the first electrical system channel) with additional power (= available dynamic secondary buffer power of the secondary DC-DC converter) by coupling the two electrical systems (also called electrical system channels). For this purpose, the balancing device interacts electrically with the primary DC-DC converter and the secondary DC-DC converter to couple or keep coupled, or decouple or keep decoupled, the primary and secondary electrical systems depending on the power demand.

[0031] In a further embodiment of the electrical system arrangement, it is provided that if the primary power supplied by the primary electrical system is less than the power required by all currently active consumers, and if the resulting shortfall in peak power can be provided by available secondary buffer power from the secondary electrical system, the balancing device closes to couple the primary electrical system with the secondary electrical system. This alternative embodiment is provided, for example, if the comfort consumers and / or safety consumers are supplied by both the primary and secondary electrical systems, for example, at 50% or 60% and 40% respectively, or the like.

[0032] The primary power output of the vehicle's electrical system, particularly the primary DC-DC converter, can be designed to supply all electrical consumers, including safety-related consumers (also known as safety consumers). This means, for example, that the maximum primary power output can correspond to the power consumption of all electrical consumers in the vehicle. Alternatively, the maximum primary power output, particularly of the primary DC-DC converter, can correspond to the power consumption of at least a proportion of all electrical consumers in the vehicle, for example, a proportion greater than 60%, especially 70% or 80%, since typically not all consumers are active at any one time, but only a portion of them.Depending on the maximum primary power that can be specified as the output power of the primary DC-DC converter, and / or the number of active consumers, the corresponding available dynamic primary buffer power of the primary DC-DC converter can vary.

[0033] The secondary electrical system is designed as a redundant system for some of the vehicle's electrical consumers, particularly safety-related ones. The maximum secondary power output of the secondary electrical system corresponds to the power consumption of all those consumers that are safety-related and / or systems with safety-relevant functions. Since safety-related consumers are rarely active during normal operation, and then only for short periods, the secondary DC-DC converter can have a correspondingly large dynamic secondary buffer capacity.

[0034] For example, such dynamic power transfer (dynamic power balancing) from the secondary electrical system to the primary electrical system occurs in the event of an overload in the primary electrical system. This is done, in particular, to prevent the primary electrical system from being disconnected from the vehicle's battery within a predefined fault tolerance time if safety parameters / limits are at risk of being violated. Such dynamic power transfer (dynamic power balancing) from the secondary electrical system to the primary electrical system can also occur to prevent the discharge of a buffer battery, especially a 12V battery, in the primary electrical system. Otherwise, if the primary electrical system's buffer battery is discharged and the overload persists, the primary electrical system would experience undervoltage, causing a safety switch, such as a high-voltage contactor, to trip and open.In other words, by providing the secondary power buffer of the secondary electrical system to the primary electrical system, the latter can be protected from overload and decoupling from the vehicle battery can be avoided. Thus, power balancing to prevent overload takes precedence over decoupling the primary electrical system from the vehicle battery.

[0035] Furthermore, it may be provided that, if the primary and secondary electrical systems are coupled and the primary power supplied is equal to or greater than the required consumer power, the balancing device opens again to decouple the primary and secondary electrical systems from each other, particularly while maintaining the necessary fault tolerance times. In other words, the primary and secondary electrical systems return to normal operation.

[0036] Additionally, it may be provided that if, in the coupled state of the primary and secondary electrical systems, an electrical system fault, for example a short circuit, undervoltage, overvoltage or overcurrent, is identified, the compensating device opens again to decouple the primary and secondary electrical systems from each other, in particular while adhering to the required fault tolerance times.

[0037] In one possible embodiment, the balancing device is arranged between the primary and secondary electrical systems, downstream of the primary and secondary electrical systems. The balancing device is self-contained. It can, for example, be a smart switch. This smart switch can be equipped with an integrated electronic circuit, for instance, for measuring current, voltage, and / or power, and / or for processing the measured signals and / or input signals, such as input signals from the primary and / or secondary electrical systems, to generate a switching signal for the switch, which acts as a disconnect switch, to couple or keep the primary and secondary electrical systems coupled or to decouple or keep them decoupled.

[0038] Preferably, the on-board battery is a high-voltage battery, for example an 800 V battery, and the secondary and primary on-board networks are low-voltage on-board networks, in particular with a voltage range between 10 V and 18 V.

[0039] The vehicle according to the invention is equipped with the on-board electrical system arrangement described above.

[0040] Exemplary embodiments of the invention are explained in more detail below with reference to drawings.

[0041] This shows: Fig. 1 schematically a vehicle with an on-board electrical system arrangement, Fig. 2. Schematic representation of the on-board electrical system arrangement in detail with a primary on-board electrical system and a secondary on-board electrical system and an intermediate balancing device in normal operation. Fig. Figure 3 schematically compares a primary DC-DC converter and a secondary DC-DC converter with regard to their power design. Fig. 4. Schematic representation of the vehicle electrical system arrangement in detail, showing a primary vehicle electrical system and a secondary vehicle electrical system, and an intermediate balancing device in case of overload in the primary vehicle electrical system. Fig. 5 schematically the on-board network arrangement in detail with a primary on-board network and a secondary on-board network and an intermediate compensation device in case of an on-board network fault in the primary on-board network.

[0042] Corresponding parts are marked with the same reference symbols in all figures.

[0043] Fig. Figure 1 schematically shows a vehicle 1 with an on-board electrical system arrangement 2. The vehicle 1 is, in particular, an electric vehicle.

[0044] The on-board electrical system 2 includes an on-board electrical system battery 3, in particular a high-voltage battery, for example an 800 V battery, for an electric drive 6, such as an electric motor.

[0045] The on-board electrical system arrangement 2 comprises at least one primary on-board electrical system 4 and one secondary on-board electrical system 5 for supplying a plurality of consumers 10.n (shown in Fig. 2).

[0046] Fig. Figure 2 schematically shows the on-board power supply arrangement 2 in detail with the primary on-board power supply 4 and the secondary on-board power supply 5 and an intermediate compensating device 8 in normal operation 100 of the on-board power supply arrangement 2. In normal operation 100, the compensating device 8 is open and the primary on-board power supply 4 and the secondary on-board power supply 5 are decoupled from each other and independent.

[0047] The primary electrical system 4 can be indirectly connected to the electrical system battery 3 via a safety switch 14 to supply primary power 4.11 to consumers 10.1 to 10.3 as primary consumers 10.0. The primary electrical system 4 can also be directly connected to the electric drive 6. The safety switch 14 is closed during normal operation 100 and supplies power to the primary electrical system 4.

[0048] The secondary electrical system 5 is directly coupled to this electrical system battery 3 to provide a secondary power 5.11 for the redundant supply of part 11.nm of the consumers 10.n as secondary consumers 11.0.

[0049] The compensating device 8 is arranged between the primary electrical system 4 and the secondary electrical system 5. It is designed to couple or keep coupled, or decouple or keep decoupled, the primary electrical system 4 and the secondary electrical system 5 depending on the power output, as described in more detail below with reference to the exemplary embodiments: In the primary electrical system 4, a regulator 20 (also called primary regulator), comprising a superimposed voltage regulator and a subordinate current regulator, is provided for supplying the primary power 4.11. The regulator 20, in particular both regulators, can be an integral part of a DC-DC converter 4.1 in the primary electrical system 4 and / or the equalization device 8.

[0050] In the secondary electrical system 5, a further regulator 22 (also called secondary regulator), in particular a superimposed voltage regulator and a subordinate current regulator, is provided for supplying the secondary power 5.11. The further regulator 22, in particular both regulators, can be an integral part of a secondary DC-DC converter 5.1 in the secondary electrical system 5 and / or the equalization device 8.

[0051] The primary electrical system 4 serves to supply the primary power to all consumers 10.n, in particular all safety consumers, such as a vehicle communication device 10.1, a steering assistance system 10.2, a brake assistance system 10.3, and all comfort consumers, such as a seat heater 10.4 or the like, in the vehicle 1.

[0052] The secondary electrical network 5 serves for redundant supply, in particular the secondary supply of a part 11.nm of the consumers 10.n, in particular all safety consumers, such as a redundant vehicle communication device 11.1, a redundant steering assistance system 11.2, a redundant brake assistance system 11.3, control units which are used for example for autonomous driving functions (ADAS), or the like, in the vehicle 1.

[0053] For dynamic load supply, in particular overload supply or peak load supply, the primary on-board network 4 can be coupled with a buffer battery 12 in addition to the on-board network battery 3.

[0054] To ensure a reliable power supply for the safety consumers, the secondary electrical system 5 is directly connected to the main electrical system battery 3.

[0055] In contrast, the primary electrical system 4 is protected in the event of a fault, for example a short circuit (exemplified as electrical system fault 106 in Fig. (5 shown) in the primary electrical system 4, the primary DC-DC converter 4.1 can be switched off. The safety loads in the primary electrical system 4 can continue to be supplied due to the direct coupling of the secondary electrical system 5 with the electrical system battery 3. A short circuit in the high-voltage electrical system of the electrical system battery 3, which is designed as a high-voltage battery, leads to the opening of the safety switch 14.

[0056] To provide the primary power 4.11, the primary electrical system 4 includes the primary DC converter 4.1, in particular a primary DC converter (also called DC / DC converter or DC / DC primary converter), which is indirectly coupled on the input side via the safety switch 14 to the electrical system battery 3 and on the output side to the consumers 10.n, in particular all comfort consumers and all safety consumers.

[0057] To provide the secondary power 5.11, the secondary on-board network 5 includes the secondary DC converter 5.1, in particular a secondary DC converter (also called DC / DC converter DC / DC secondary converter), which is directly coupled on the input side to the on-board battery 3 and on the output side to the safety-relevant part 11.nm of the consumers 10.n for the redundant supply of this safety-relevant part 11.nm.

[0058] In the example, both the primary DC converter 4.1 and the secondary DC converter 5.1 are connected in parallel with the consumers to be supplied 10.n and with the redundant part 11.nm of these respectively.

[0059] The primary DC-DC converter 4.1 and the secondary DC-DC converter 5.1 can, for example, be configured as intelligent converters (also called smart converters). Such an intelligent converter, in particular a DC-DC converter, can, for example, be equipped with an integrated electronic circuit that is configured, for example, to measure a current, a voltage, and / or a power, and / or to process the measured signals, and / or to generate a switching signal for the balancing device 8.

[0060] For example, the primary DC-DC converter 4.1, as controller 20, can include the previously described superimposed voltage control and subordinate current control, which provide a base load current for the primary electrical system 4 at the output, corresponding to a base load or a static power requirement of the consumers 10.n. The secondary DC-DC converter 5.1, for example, as a further controller 22, can also include a superimposed voltage control and a subordinate current control, which provides an adjustable DC voltage for the secondary electrical system 5 at the output.

[0061] Preferably, the primary DC-DC converter 4.1 includes the controller 20, which is voltage-controlled in the uncoupled state and, in the absence of power in the primary electrical system 4, is configured to current-controlled for current limiting in the primary electrical system 4. In other words, only if the power of the primary DC-DC converter 4.1 is insufficient does the controller 20 switch from the higher-level voltage control to the lower-level current control. Consequently, the primary electrical system 4 and the secondary electrical system 5 are coupled to each other via the equalizing device 8.

[0062] By combining current limiting via controller 20 (also called primary controller) in primary DC-DC converter 4.1 and voltage limiting via the additional controller 22 (also called secondary controller) in secondary DC-DC converter 5.1 when primary electrical system 4 and secondary electrical system 5 are coupled, oscillations of the two potentially opposing control circuits can be reduced or even avoided. This enables stable operation of the electrical system 2. In particular, the voltage regulator of controller 20 and / or the additional controller 22 can provide voltage limiting with an adjustable or dynamically defined limit. The current regulator of controller 20 and / or the additional controller 22 can provide current limiting with an adjustable or dynamically defined limit.

[0063] In particular, the current regulator of controller 20 (= primary regulator) sets a current limit such that a minimum number of consumers 10n can be supplied. For example, the current regulator of controller 20 can be configured to provide a base load of, for example, 95% for a specified minimum number of consumers 10n. If this value is exceeded by a dynamic load demand from additional consumers 10n, the voltage regulator of the further controller 22 (= secondary regulator) can provide a dynamic buffer power up to the specified voltage limit for both networks by switching on the balancing device 8 and coupling both networks (primary on-board network 4 and secondary on-board network 5) and superimposing it on the current limit. For this purpose, the primary converter 4.1 and the secondary converter 5.1 are in the coupled state, in which the balancing device 8 is closed, as shown in Fig. 3 shown, connected in parallel to each other.

[0064] The invention enables an intelligent connection of the two vehicle electrical systems, the primary electrical system 4 and the secondary electrical system 5, by means of the balancing device 8, in order to utilize the vehicle electrical system battery 3 in interaction with the two DC converters, the primary DC converter 4.1 and the secondary DC converter 5.1, in particular their available dynamic buffer capacities in addition to the static capacities (primary capacity 4.11, secondary capacity 5.11), and optionally the buffer battery 12 as efficiently as possible, thus avoiding an increase in the size of the vehicle electrical system battery 3, the two DC converters (primary DC converter 4.1, secondary DC converter 5.1) and / or the buffer battery 12 and using fewer components.

[0065] In normal operation, 100 of the on-board power supply arrangement 2, as described in Fig. As shown in Figure 2, the balancing device 8 is not electrically interacting with the primary DC-DC converter 4.1 and the secondary DC-DC converter 5.1 and is open to decouple or keep decoupled the primary electrical system 4 and the secondary electrical system 5. The primary electrical system 4 supplies all active consumers 10.n, in particular all active comfort consumers and all active safety consumers. No power balancing takes place between the two electrical systems.

[0066] The balancing device 8 is particularly self-contained, for example, as a separate intelligent switch 8.1 (also called a smart switch). The intelligent switch 8.1 can, for example, be equipped with an integrated electronic circuit (not shown), for example, for measuring current, voltage, and / or power in the respective vehicle electrical system (primary electrical system 4 and / or secondary electrical system 5) and / or for processing the measured signals, in particular the current signals, voltage signals, and / or power signals, and / or input signals 8.2, for example, a primary input signal 8.21 of the primary DC-DC converter 4.1 and / or a secondary input signal 8.22 of the secondary DC-DC converter 5.1, to generate a switching signal for the switch 8.1, which is designed as a disconnect switch, to couple or keep coupled the primary electrical system 4 and the secondary electrical system 5, or to decouple or keep decoupled from each other.

[0067] The compensating device 8 can be easily integrated into existing on-board network arrangements 2 of a vehicle 1 with multiple on-board networks, in particular retrofitted.

[0068] Furthermore, the on-board network arrangement 2 can be configured to couple, keep coupled, uncouple or keep uncoupled the two on-board networks (primary on-board network 4 and secondary on-board network 5) by means of the compensating device 8 during a journey of the vehicle 1 or when the vehicle 1 is stationary.

[0069] In the example shown, switch 8.1 is open in normal operation 100 of the on-board power supply arrangement 2 when the primary power 4.11 supplied by the primary on-board power supply 4 is greater than the power 11 required by all currently active consumers 10.n.

[0070] The secondary electrical system 5 supplies the safety-relevant part 11.nm of the consumer 10.n. during normal operation 100 of the electrical system arrangement 2.

[0071] Alternatively, switch 8.1 can be closed in normal operation (not shown), so that the safety consumers are supplied equally by both the primary on-board network 4 and the secondary on-board network 5.

[0072] Fig. Figure 3 schematically shows the primary DC converter 4.1 and the secondary DC converter 5.1 in comparison with regard to their power design.

[0073] To optimize the on-board network arrangement 2, the primary DC converter 4.1 and / or the secondary DC converter 5.1 are set up to provide, in addition to the primary power 4.11 or the secondary power 5.11 respectively, a dynamic buffer power, in particular a dynamic primary buffer power 4.12 or a dynamic secondary buffer power 5.12 respectively.

[0074] In the operation of the on-board power supply arrangement 2, depending on the number of active consumers, 10.n and 11.nm (shown in Fig. 2) in the respective on-board network (the primary on-board network 4 and / or the secondary on-board network 5) an instantaneously available dynamic primary buffer power 4.12 and / or an instantaneously available dynamic secondary buffer power 5.12 results when an instantaneous consumer power 11 of all active consumers 10.n or a part thereof 11.nm (represented in Fig. 2) of which in the primary electrical system 4 or in the secondary electrical system 5 is less than a maximum possible primary output power of the primary DC converter 4.1 or than a maximum possible secondary output power of the secondary DC converter 5.1.

[0075] The primary output power of the primary DC-DC converter 4.1 is a predetermined operating parameter of the primary DC-DC converter 4.1.

[0076] The secondary output power of the secondary DC converter 5.1 is a predefined operating parameter of the secondary DC converter 5.1.

[0077] The secondary DC converter 5.1 differs in its design from the primary DC converter 4.1 in at least the following operating parameters: - Level of output power, where the primary output power of the primary DC-DC converter 4.1 is higher than the secondary output power of the secondary DC-DC converter 5.1; - Availability, whereby the secondary DC converter 5.1 is highly available by being directly coupled to the on-board battery 3; - Dynamics, wherein the secondary DC converter 5.1 is designed to be highly dynamic, in that it is designed with a dynamics in the microsecond range, for example with a 100 µs clocking to provide the secondary power 5.11.

[0078] Both the primary electrical system 4 and the secondary electrical system 5 can thus be configured to supply consumers 10.n or the redundant part 11.nm thereof with static power (= primary power 4.11, secondary power 5.11) and / or dynamic buffer power (= dynamic primary buffer power 4.12, dynamic secondary buffer power 5.12) by means of a power transfer 16 between the primary electrical system 4 and the secondary electrical system 5 by means of the balancing device 8.

[0079] The available dynamic buffer power, preferably the dynamic secondary buffer power 5.12 of the secondary DC-DC converter 5.1 in the secondary electrical system 5, can be used by means of the balancing device 8, in particular as a buffer for dynamic processes, especially required load peaks such as current peaks and thus power peaks, in the other electrical system, especially in the primary electrical system 4, as described below with reference to the examples. Furthermore, by means of the balancing device 8 and its electrical interaction with the primary DC-DC converter 4.1 and the secondary DC-DC converter 5.1, it can be ensured that when the available dynamic secondary buffer power 5.12 of the secondary electrical system 5 is used in the primary electrical system 4, more consumers 10.n with comfort functions can be activated or remain activated.

[0080] The balancing device 8 enables intelligent power transfer 16 (also called power balancing, power feed-in, power distribution) to match the current or instantaneous consumer demand (= instantaneous consumer power 11 of the active consumers 10.n, 11.nm), for example intelligent cross currents between the primary on-board network 4 and the secondary on-board network 5.

[0081] Fig. Figure 4 schematically shows the electrical system arrangement 2 in detail, including the primary electrical system 4, the secondary electrical system 5, and the intermediate balancing device 8, in an overload situation 102 in the primary electrical system 4. This means that the primary DC-DC converter 4.1 cannot supply the primary electrical system 4, or cannot supply it sufficiently. For example, a comparator integrated into one of the DC-DC converters and / or the balancing device 8 identifies that the primary power 4.11 supplied by the primary electrical system 4 is less than the load power 11 required by all currently active consumers 10.n in the primary electrical system 4.

[0082] If this case is identified, the balancing device 8, which is in electrical interaction with the primary DC-DC converter 4.1 and the secondary DC-DC converter 5.1, can couple the primary electrical system 4 and the secondary electrical system 5, for example by closing the switch 8.1, or keep them coupled, for example by keeping the switch 8.1 closed. This allows any missing peak power resulting from this difference between primary power 4.11 and consumer power 11 to be provided, in particular fed into the primary electrical system 4, by means of a correspondingly available dynamic secondary buffer power 5.12 of the secondary electrical system 5 via the "closed" balancing device 8 by means of power transfer 16.

[0083] For example, such dynamic power transfer 16 or dynamic power balancing from the secondary electrical system 5 to the primary electrical system 4 occurs in an overload case 102 in the primary electrical system 4, in order to provide, in particular, missing dynamic load requirements or peak power through the dynamic secondary power buffer 5.12 and to prevent a safety decoupling of the primary electrical system 4 from the electrical system battery 3 within a specified fault tolerance time in the event of an imminent violation of safety parameters and / or safety limits. If the missing peak power continues to increase and exceeds safety limits, the balancing device 8 opens within fault tolerance times and decouples the two electrical systems from each other.

[0084] To ensure the supply of the active consumers 10.n in the primary on-board network 4 in the event of overload 102 and thus in the absence of peak power, the required consumer power 11 in the primary on-board network 4 is provided by the primary power 4.11 and the dynamic secondary buffer power 5.12, which is fed into the primary on-board network 4 by power transmission 16.

[0085] In detail, when an overload or maximum possible load is identified, in particular a maximum possible consumer power 11 requested which exceeds the primary power 4.11 but is still below the safety power of the safety switch 14, a dynamic additional buffer power of the buffer battery 12 is first used in the primary on-board network 4 and this is discharged to supply the consumers 10.n.

[0086] During discharge, a voltage measurement is performed in both the primary electrical system 4 and the secondary electrical system 5, for example, by means of a control circuit of the equalization device 8. If necessary, the voltage limit value in the secondary electrical system 5 is adopted as the voltage limit value in the primary electrical system 4. The primary DC-DC converter 4.1 is set to a higher voltage limit value than the secondary DC-DC converter 5.1, so that the primary DC-DC converter 4.1 continues to operate in current limiting mode after the electrical systems 4 and 5 are coupled, even when the primary electrical system 4 and secondary electrical system 5 are coupled. The secondary DC-DC converter 5.1 takes over voltage regulation. The equalization device 8, in particular its switch 8.1, is closed. The secondary DC-DC converter 5.1 supplies the consumers 10 with its available dynamic secondary buffer power 5.12.n in the primary on-board network 4 according to power transmission 16 via the closed compensating device 8.

[0087] When transitioning from overload condition 102 back to normal load condition and thus to normal operation 100, for example by reducing the dynamic load requirements of the consumers 10.n and consequently by reducing the consumer power 11 to a value below the provided or available primary power 4.11, or when current flows via the balancing device 8 from the primary electrical system 4 towards the secondary electrical system 5, the balancing device 8 can be opened again and the electrical system arrangement 2 is switched to normal operation 100. For this purpose, the voltage limit for the primary DC-DC converter 4.1 must first be reduced, in particular to the voltage value that corresponds to the normal battery voltage value or the normal primary voltage value of the primary electrical system 4. The secondary DC-DC converter 5.1 is set to a fixed or steady-state voltage regulation. In addition, the primary DC-DC converter 4.1 can be...1 is reset to its full power of 100% to prevent, for example, toggling. Then, switch 8.1 of the balancing device 8 is opened.

[0088] After a predetermined time, for example in the range of seconds, especially 30 s, the power of the primary DC converter 4.1 can be set back to 95% in normal operation 100 by means of the voltage regulation.

[0089] This creates a defined state, whereby the compensating device 8 is opened as soon as the primary DC converter 4.1 is back in normal operation 100 and thus voltage-controlled and no longer in current limiting and therefore no longer current-controlled.

[0090] Fig. Figure 5 schematically shows the on-board network arrangement 2 in detail with the primary on-board network 4 and the secondary on-board network 5 and the compensating device 8 connected between them in the event of an on-board network fault 106, for example a short circuit, an overvoltage, an undervoltage, an overcurrent, in the primary on-board network 4.

[0091] In order to ensure the interdependence of the two on-board networks, the primary on-board network 4 and the secondary on-board network 5, when the compensating device 8 is closed, in particular when the switch 8.1 is closed, and in the event of an on-board network fault 106, the compensating device 8, in particular its integrated electronic circuit, is designed to open the switch 8.1 within fault tolerance times, in particular in the microsecond or millisecond range, and thus to decouple the primary on-board network 4 and the secondary on-board network 5 from each other.

[0092] For example, the compensation device 8 is designed to identify an undervoltage, an overvoltage and / or an overcurrent in one of the on-board networks as an on-board network fault 106 based on current measurements, voltage measurements or the like, and to automatically open the switch 8.1 in the event of an identified on-board network fault 106.

[0093] Furthermore, the compensating device 8, in particular its electronics, is designed not to close in the event of a vehicle electrical system fault 106, in particular if an overload is imminent or the like, and if the switch 8.1 is open.

[0094] In particular, switch 8.1 is opened abruptly under load in the event of a vehicle electrical system fault 106, for example within milliseconds or microseconds, for example at less than 100 µs.

[0095] While this does result in limitations to comfort functions, as potential comfort consumers cannot be supplied, the so-called ASIL-D independence is not compromised. Exceptions may occur in fault conditions that do not compromise ASIL integrity and do not affect the opening state of the balancing device 8 (also called the vehicle electrical system balancer), for example, a failure or fault in the primary DC-DC converter 4.1. Such a balancing device 8 has the advantage that propulsion is possible without dependence on the energy content of the vehicle electrical system battery 3 in the primary electrical system 4, and / or a driver of the vehicle 1 can, for example, escape from safety-critical situations, such as preventing a loss of propulsion in a tunnel without a shoulder or similar obstacle.

[0096] Further example situations for the on-board network arrangement 2 according to the invention are described below: In the case of a winter warm-up drive, in which many active heating consumers in the primary electrical system 4 typically lead to an overload (overload case 102 in Fig. 4) The dynamic secondary buffer capacity 5.12 can be used by closing the compensating device 8, in particular its switch 8.1. This allows, for example, an occupant of the vehicle 1 to switch on comfort consumers, such as a seat heater 10.4 or the like, even in winter.

[0097] In the event of a brief, high current demand, for example during a rapid steering and braking maneuver with a short-term high current requirement in the primary electrical system 4 and the secondary electrical system 5, the buffer battery 12 can buffer (provide or supply) the peak power demand in the primary electrical system 4 and the secondary electrical system 5. For this purpose, the balancing device 8 (on-board electrical system balancer) remains closed, as the supplied voltage remains within the target range. This does not result in any limitations in comfort functions for the occupant. The occupant also does not perceive any limitations.

[0098] If the buffer battery 12 in the primary electrical system 4 and the dynamic secondary buffer power 5.12 of the secondary DC-DC converter 5.1 cannot supply the peak power demand (i.e., cannot buffer), then the balancing device 8, in particular the switch 8.1, opens, since the voltage is not within the target range and the battery voltage drops. This, in turn, leads to the deactivation of active comfort consumers (degradation in the primary electrical system 4), for example, according to a deactivation priority list. This safety-relevant deactivation of comfort consumers and / or comfort functions is perceived by the occupant as a restriction, for example, through the deactivation of certain noticeable comfort consumers, such as the seat heating 10.4, a blower, in particular a ventilation blower, or the like. Reference symbol list 1 vehicle 2 On-board electrical system arrangement 3 On-board battery 4 Primary electrical system 4.1 Primary DC converter 4.11 Primary power 4.12 dynamic primary buffer power 5 Secondary electrical system 5.1 Secondary DC converter 5.11 Secondary power 5.12 dynamic secondary buffer power 6 electric drive 8 Compensating device 8.1 Switches 8.2 Input signal 8.21 Primary input signal 8.22 Secondary input signal 10.0 Primary consumers 11.0 Secondary consumers 10.1, 11.1 Vehicle communication equipment 10.2, 11.2 Steering assistance system 10.3, 11.3 Brake Assist System 10.4, 11.4 Seat heating 10.n, 11.nm Consumer 11 Consumer performance 12 backup batteries 14 safety switches 16 Power transmission 20 controllers (primary controllers) 22 additional controllers (secondary controllers) 100 Normal operation 102 Overload case 106 On-board power supply faults

Claims

On-board electrical system arrangement (2) with at least one primary on-board electrical system (4) and one secondary on-board electrical system (5) for supplying a plurality of consumers (10.n) in a vehicle (1), characterized in that the primary on-board electrical system (4) can be coupled or is coupled to an on-board electrical system battery (3) for providing a primary power (4.11) for supplying the consumers (10.n) and the secondary on-board electrical system (5) for providing a secondary power (5.11) for the redundant supply of a part (11.nm) of the consumers (10.n) is coupled to the on-board battery (3), wherein a switchable equalizing device (8) is arranged between the primary on-board network (4) and the secondary on-board network (5), which, depending on the power supply, couples or keeps the primary on-board network (4) and the secondary on-board network (5) to each other or decouples or keeps them decoupled from each other, wherein in normal operation (100) of the primary on-board network (4) and the secondary on-board network (5) the equalizing device (8) is open in order to decouple the primary on-board network (4) and the secondary on-board network (5) from each other, wherein in the coupled state of the primary on-board network (4) and the secondary on-board network (5) a current regulator (20) for providing the primary power (4.11) in the primary on-board network (4) and a voltage regulator (5.11) for providing the secondary power (5.11) in the secondary on-board network (5) and in the uncoupled state both in the primary on-board network (4) and in the secondary on-board network (5) as regulators (20, 22) respectively a voltage regulator to provide the primary power (4.11) and the secondary service (5.11) are provided. On-board electrical system arrangement (2) according to claim 1, characterized in that the primary on-board electrical system (4) for providing the primary power (4.11) comprises a primary DC-DC converter (4.1) which is coupled on the input side to the on-board electrical system battery (3) and on the output side to the consumers (10.n) and which, as a controller (20), comprises a superimposed voltage control and a subordinate current control which, in the coupled state of the primary on-board electrical system (4) and the secondary on-board electrical system (5), provides at the output a base load current corresponding to a base load of the consumers (10.n). On-board electrical system arrangement (2) according to claim 1 or 2, characterized in that the secondary on-board electrical system (5) for providing the secondary power (5.11) comprises a secondary DC converter (5.1) which is coupled on the input side to the on-board electrical system battery (3) and on the output side to a part (11.nm) of the consumers (10.n) and which comprises as a further regulator (22) a superimposed voltage regulation and a subordinate current regulation. On-board electrical system arrangement (2) according to claim 2 or 3, characterized in that the primary on-board electrical system (4) comprises a buffer battery (12) for providing dynamic buffer power. On-board power supply arrangement (2) according to one of the preceding claims, characterized in that the compensating device (8) is in electrical interaction with the primary DC converter (4.1) and the secondary DC converter (5.1) in order to couple or keep coupled or decouple or keep decoupled the primary on-board power supply (4) and the secondary on-board power supply (5) depending on the power output. On-board power supply arrangement (2) according to claim 5, characterized in that if the primary power (4.11) provided by the primary on-board power supply (4) is less than one or the consumer power (11) required by all currently active consumers (10.n) and a missing overload power or peak power resulting from this difference between primary power (4.11) and consumer power (11) can be provided by an available secondary buffer power (5.12) of the secondary on-board power supply (5), the balancing device (8) closes in order to couple the primary on-board power supply (4) with the secondary on-board power supply (5). On-board power supply arrangement (2) according to claim 6, characterized in that when, in the coupled state of primary on-board power supply (4) and secondary on-board power supply (5), the primary power supplied (4.11) is equal to or greater than the required consumer power (11), the compensating device (8) opens again to decouple the primary on-board power supply (4) and the secondary on-board power supply (5) from each other. On-board power supply arrangement (2) according to claim 6 or 7, characterized in that if an on-board power supply fault (106) is identified or has been identified in the coupled state of primary on-board power supply (4) and secondary on-board power supply (5), the compensating device (8) opens again to decouple the primary on-board power supply (4) and the secondary on-board power supply (5) from each other. On-board electrical system arrangement (2) according to one of the preceding claims, characterized in that the on-board electrical system battery (3) is a high-voltage battery and the primary on-board electrical system (4) and the secondary on-board electrical system (5) are each a low-voltage on-board electrical system. Vehicle (1) with an on-board electrical system arrangement (2) according to one of the preceding claims.

Images