On-board electrical system for a vehicle

Abstract

The invention relates to an on-board electrical system (10) for a vehicle (20), comprising a high-voltage battery (3) for providing energy at a high voltage, several electrical consumers (4, 5), including at least one safety-critical consumer (4) and at least one non-safety-critical consumer (5), a DC / DC converter device (1) for converting the high voltage into at least one low voltage for supplying the consumers (4, 5), an energy management system (6) for controlling and / or regulating at least the non-safety-critical consumers (5), wherein the DC / DC converter device (1) has a plurality of DC / DC converters (2.1 to 2.n) with a total converter power sufficient to supply all connected consumers (4, 5), wherein the converter power is dimensioned such that in the event of a failure of one of the DC / DC converters (2.1 to 2.n), all safety-critical consumers (4) are supplied by the remaining DC / DC converters (2.1 to 2.n).n) are supplied with energy, the energy management system (6) being configured to switch off the non-safety-critical loads (5) in the event of a failure of one of the DC / DC converters (2.1 to 2.n). In the DC / DC converter device (1) the DC / DC converters (2.1 to 2.n) are electrically connected in parallel by means of busbars or cables.

Description

[0001] The invention relates to an on-board electrical system for a vehicle according to the preamble of claim 1.

[0002] DE 10 2021 005 548 A1 describes a DC-DC converter comprising several DC-DC converter modules with differing electrical input and output voltages, which are designed as a common integrated unit and can be electrically interconnected in several subsystems such that a high-voltage voltage can be converted into various low-voltage voltages. Furthermore, a component arrangement for a vehicle's high-voltage electrical system is described.

[0003] German patent DE 10 2022 113 199 A1 describes a motor vehicle with a high-voltage electrical system and a low-voltage electrical system, wherein two DC / DC converters connect the low-voltage electrical system to the high-voltage electrical system. Each DC / DC converter has a control unit for regulating the voltage conversion, and the DC / DC converters are spatially separated within the motor vehicle. A communication line between the hardware controllers allows control information to be transmitted from one hardware controller to the other so that it can be taken into account in the latter's control operation.

[0004] DE 10 2021 102 261 A1 discloses a method for operating a DC-DC converter device with several DC-DC converter units connected in parallel, wherein, in order to set a desired output voltage, these are operated based on a current-mode control, so that stable control is ensured even with fluctuating load on the respective DC-DC converter units.

[0005] German patent application DE 10 2021 122 054 A1 describes a DC / DC converter unit for an electric or hybrid vehicle, comprising a first and a second DC / DC converter. The outputs of both DC / DC converters are connected in parallel within a low-voltage electrical system. Each DC / DC converter is directly supplied by a battery bank or sub-battery, and a switching signal allows each converter to be switched between active and standby modes. In a first operating mode, when both battery banks and both DC / DC converters are functional, the converters continuously and alternately switch between active and standby modes. If only one of the two DC / DC converters is functional, it supplies power to the low-voltage electrical system.

[0006] The invention is based on the objective of providing a novel on-board electrical system for a vehicle, a novel vehicle and a novel method for operating the on-board electrical system.

[0007] The problem is solved according to the invention by a vehicle electrical system with the features of claim 1.

[0008] Advantageous embodiments of the invention are the subject of the dependent claims.

[0009] A vehicle electrical system is proposed, comprising a high-voltage battery for providing high-voltage power, several electrical consumers, including at least one safety-critical consumer and at least one non-safety-critical consumer, a DC / DC converter device for converting the high-voltage voltage into at least one low-voltage voltage to supply the consumers, and an energy management system for controlling and / or regulating at least the non-safety-critical consumers. The DC / DC converter device includes multiple DC / DC converters with a total conversion power sufficient to supply all connected consumers.According to the invention, the converter power is dimensioned such that if one of the DC / DC converters fails, all safety-critical consumers are supplied with energy by the remaining DC / DC converters, wherein the energy management system is configured to switch off the non-safety-critical consumers if one of the DC / DC converters fails.

[0010] According to the invention, the DC / DC converters in the DC / DC converter device are electrically connected in parallel by means of busbars or cables.

[0011] According to the invention, the at least one safety-critical load and the at least one non-safety-critical load are each connected to a separate terminal on the DC / DC converter device, and the DC / DC converter device is configured to switch these terminals on or off as needed. The energy management system can be located inside or outside the DC / DC converter device.

[0012] According to the invention, the at least one safety-critical load and the at least one non-safety-critical load are connected together to the DC / DC converter device, and the energy management system arranged outside the DC / DC converter device is configured to switch on and / or off at least the at least one non-safety-critical load as needed.

[0013] In one embodiment, the energy management system is configured to dynamically shut down at least one of several non-safety-critical consumers in the event of a fault, based on the actual power demand of the non-safety-critical consumers.

[0014] An electrically powered vehicle with an on-board network according to the invention is also described, wherein the high-voltage battery is configured to supply an electric machine for driving the vehicle.

[0015] The at least one safety-critical component can be a braking system and / or a steering system of the vehicle and / or an Advanced Driver Assistance System (ADAS). The Advanced Driver Assistance System, also known as ADAS, is a driver assistance system with electronic auxiliary devices in motor vehicles to support the driver in certain driving situations. Safety aspects play a crucial role, especially in the planning, guidance, and stabilization of a driving task, but are also always important in driver assistance systems.

[0016] The at least one non-safety-critical consumer can be entertainment electronics and / or interior lighting and / or air conditioning of the vehicle.

[0017] A method for operating a vehicle electrical system according to the invention is also described, wherein, in the event of a failure of one of the DC / DC converters, the non-safety-critical consumers are switched off by the energy management system.

[0018] According to the present invention, non-safety-critical consumers are switched off in the event of a failure of a DC / DC converter.

[0019] By switching off non-safety-critical loads in the event of a fault, the redundancy of the converter power integrated into the DC / DC converter device can be utilized. This reduces the total converter power required, thereby saving space and costs.

[0020] Exemplary embodiments of the invention are explained in more detail below with reference to drawings.

[0021] This shows: Fig. 1. A schematic view of an on-board electrical system with a DC / DC converter device in normal operation, Fig. 2. A schematic view of the on-board electrical system with the DC / DC converter device in the event of a rail failure, and Fig. 3. A schematic view of a vehicle.

[0022] Corresponding parts are marked with the same reference symbols in all figures.

[0023] Fig. Figure 1 is a schematic view of an on-board network 10 with a DC / DC converter device 1 in normal operation, in which the DC / DC converter device 1 converts a high-voltage voltage from a high-voltage battery 3 into at least a low-voltage voltage to supply consumers 4, 5, including safety-critical consumers 4 and non-safety-critical consumers 5.

[0024] An energy management system 6 may be arranged for the control and / or regulation of the non-safety-critical consumers 5.

[0025] The DC / DC converter device 1 comprises a plurality of DC / DC converters 2.1 to 2.n, so-called rails. The DC / DC converters 2.1 to 2.n are referred to as rails because they are frequently electrically connected via busbars. However, electrical connection via cables is also possible. The DC / DC converters 2.1 to 2.n serve to ensure high energy availability for supplying the safety-critical loads 4.

[0026] To achieve these security objectives, the following measures are required in the Fig. 1 and Fig. 2 For example, four DC / DC converters 2.1 to 2.4 with a power of, for example, 1.5 kW each, i.e. a total power of 6 kW, are arranged in the DC / DC converter device 1.

[0027] This total power (in the present example 6 kW) is available for all consumers 4, 5, that is also the non-safety-critical consumers 5.

[0028] From a functional safety perspective, a portion of the DC / DC converters 2.1 to 2.4, for example DC / DC converter 2.1, serves as redundancy. Therefore, only the power of the remaining DC / DC converters 2.2 to 2.4 is available to meet the safety objectives.

[0029] Fig. Figure 2 is a schematic view of the on-board network 10 with the DC / DC converter device 1 in the event of a rail failure, i.e., one of the DC / DC converters 2.4. The remaining DC / DC converters 2.1 to 2.3 supply the safety-critical loads 4. The non-safety-critical loads 5 are switched off by the energy management system 6.

[0030] The power of the remaining DC / DC converters 2.1 to 2.3 is therefore available to the safety-critical consumers 4, thus ensuring their supply.

[0031] The DC / DC converter device 1 can be arranged in an electrically powered vehicle 20, wherein the high-voltage battery 3 can supply an electric machine for driving the vehicle 20. The consumers 4, 5 are safety-critical consumers 4 and non-safety-critical consumers 5 of the vehicle 20 and are supplied with the low-voltage voltage via the DC / DC converter device 1.

[0032] The shutdown of the non-safety-critical consumers 5 in the event of a fault by the energy management system 6 can also be carried out dynamically on the basis of an actual load of the vehicle electrical system 10, in particular a low-voltage vehicle electrical system, i.e. the power requirement of the consumers 4, 5 included therein, in particular the non-safety-critical consumers 5.

[0033] By switching off the non-safety-critical loads 5 in the event of a fault, the power intended for redundancy of the DC / DC converter device 1 can be used. The total power required by the DC / DC converter device 1 is thus reduced, saving space and costs.

[0034] The DC / DC converter device 1 is generously designed with several DC / DC converters 2.1 to 2.n so that it meets the power requirements of all consumers 4, 5 and that if one of the DC / DC converters 2.1 to 2.n fails, the remaining DC / DC converters 2.1 to 2.n still supply enough power for the safety-critical consumers 4 if the non-safety-critical consumers 5 are at least partially switched off.

[0035] For this purpose, the DC / DC converters 2.1 to 2.n are connected in parallel in the DC / DC converter device 1 so that the safety-critical areas can always be switched to the functioning DC / DC converters 2.1 to 2.n. This can, for example, be done internally in the DC / DC converter device 1, so that each on-board network area, e.g., the safety-critical loads 4 and the non-safety-critical loads 5, loads 4, 5 grouped together, or each load 4, 5 individually, has its own connection on the DC / DC converter device 1, and these connections are switched to or from the DC / DC converters 2.1 to 2.n internally in the DC / DC converter device 1 as needed.

[0036] Alternatively, the DC / DC converter device 1 can be designed in parallel, with the vehicle electrical system sections being connected together to the DC / DC converter device 1 and being switched on and / or off externally, for example by means of the energy management system 6, so that in the event of a fault (failure of a DC / DC converter 2.1 to 2.n) the non-safety-critical consumers 5 are no longer supplied and the safety-critical consumers 4 are reliably supplied by the remaining DC / DC converters 2.1 to 2.n.

[0037] In another, alternative embodiment not shown, the DC / DC converter device can also be designed so that some of the converters serve as redundancy, meaning that more converters are provided than are needed for operation. In this case, with n converters, for example, m (with m <n) Wandler zur Redundanz eingeplant sein und im normalen Betrieb nicht benötigt werden. So könnte dann sogar noch bei einem Ausfall von m der n Wandler die nichtsicherheitskritischen Verbraucher weggeschalten werden und die Versorgung sicherheitskritische Verbraucher bleibt mit den verbleibenden Wandlern gewährleistet.For example, if four DC / DC converters are required in the DC / DC converter device for normal operation, five or six DC / DC converters could be arranged and installed in the DC / DC converter device for redundancy, so that the failure of one or even two DC / DC converters would already be protected by the redundancy and only then would the non-safety-critical consumers be switched off.

[0038] Safety-critical consumers 4 can be, for example, the braking system and / or the steering system of the vehicle 20. Non-safety-critical consumers 5 can include, for example, the entertainment electronics, interior lighting, and air conditioning of the vehicle 20.

[0039] Fig. Figure 3 is a schematic view of an electrically powered vehicle 20, which is equipped with the above-described and in Fig. 1 and Fig.The vehicle 20 can be equipped with the on-board network 10 shown in section 2. The vehicle 20 can, for example, be a passenger car, a commercial vehicle, or a bus. Reference symbol list 1 DC / DC converter device 2.1 to 2.n DC / DC converters 3 high-voltage batteries 4 consumers, safety-critical consumers 5 consumers, non-safety-critical consumers 6 Energy Management System 10 On-board electrical system 20 vehicles

Claims

[1] On-board electrical system (10) for a vehicle (20), comprising a high-voltage battery (3) for providing energy at a high voltage, several electrical consumers (4, 5), including at least one safety-critical consumer (4) and at least one non-safety-critical consumer (5), a DC / DC converter device (1) for converting the high voltage into at least one low voltage for supplying the consumers (4, 5), an energy management system (6) for controlling and / or regulating at least the non-safety-critical consumers (5), wherein the DC / DC converter device (1) comprises a plurality of DC / DC converters (2.1 to 2.n) with a total converter power sufficient to supply all connected loads (4, 5), and wherein the converter power is dimensioned such that if one of the DC / DC converters (2.1 to 2.n) fails, all safety-critical loads (4) are supplied with energy by the remaining DC / DC converters (2.1 to 2.n), wherein the energy management system (6) is configured to switch off the non-safety-critical loads (5) if one of the DC / DC converters (2.1 to 2.n) fails. characterized by , that in the DC / DC converter device (1) the DC / DC converters (2.1 to 2.n) are electrically connected in parallel by means of busbars or cables and - the at least one safety-critical load (4) and the at least one non-safety-critical load (5) are each connected to a separate terminal on the DC / DC converter device (1), wherein the DC / DC converter device (1) is configured to switch these terminals on or off to the DC / DC converters (2.1 to 2.n) as required, or - the at least one safety-critical load (4) and the at least one non-safety-critical load (5) are connected together to the DC / DC converter device (1), wherein the energy management system (6) arranged outside the DC / DC converter device (1) is configured to switch on and / or off at least the at least one non-safety-critical load (5) as required. [2] On-board electrical system (10) according to claim 1, characterized by , that the energy management system (6) is configured to dynamically shut down at least one of several non-safety-critical consumers (5) in the event of a fault, based on the actual power demand of the non-safety-critical consumers (5).

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