DE-102024132782-A1 - Electrical system for a motor vehicle that is at least partially electrically powered, and methods for operating the electrical system.

DE102024132782A1DE 102024132782 A1DE102024132782 A1DE 102024132782A1DE-102024132782-A1

Abstract

The invention relates to an electrical system (16) for a motor vehicle (10) that is at least partially electrically powered, comprising at least one electrical energy storage device (14) for providing electrical energy to at least one consumer (18) of the electrical system (16), wherein the at least one consumer (18) is electrically coupled to the electrical energy storage device (14) via at least one upstream distribution board (22), and wherein the electrical energy storage device (14) comprises a disconnect switch (24) for disconnecting an electrical connection to the upstream distribution board (22) and an electronic computing device (20) for controlling the disconnect switch (24), wherein the upstream distribution board (22) is provided without a fuse, and wherein the electronic computing device (20) is additionally configured to determine an overload condition at the upstream distribution board (20) and, depending on a certain overload, the electronic computing device (20) generates a control signal (26) to open the disconnect switch (24). Furthermore, the invention relates to a method for operating the electrical on-board network (16).

Inventors

Steffen Krueger
Bernhard Besler
Konrad Hanakam

Assignees

BAYERISCHE MOTOREN WERKE AKTIENGESELLSCHAFT

Dates

Publication Date: 20260513
Application Date: 20241111

Claims (10)

Electrical system (16) for a motor vehicle (10) that is at least partially electrically powered, comprising at least one electrical energy storage device (14) for providing electrical energy to at least one consumer (18) of the electrical system (16), wherein the at least one consumer (18) is electrically coupled to the electrical energy storage device (14) via at least one upstream distribution board (22), and wherein the electrical energy storage device (14) comprises a disconnect switch (24) for disconnecting an electrical connection to the upstream distribution board (22) and an electronic computing device (20) for controlling the disconnect switch (24), characterized in that the upstream distribution board (22) is provided at least partially without fuses, in particular without fuses, and wherein the electronic computing device (20) is additionally configured to determine an overload condition at the upstream distribution board (20) and, depending on a certain overload, the electronic computing device (20) generates a control signal (26) to open the disconnect switch (24).
Electrical system (16) according to Claim 1 , characterized in that the electronic computing device (20) takes into account a current operating state of the motor vehicle (10) when determining the overload.
Electrical system (16) according to Claim 2 , characterized in that the electronic computing device (20) determines the overload in a park state as the operating state of the motor vehicle (10).
Electrical on-board network (16) according to one of the preceding claims, characterized in that the electronic computing device (20) is additionally designed to determine a latent error at the upstream power distributor (22).
Electrical on-board network (16) according to one of the preceding claims, characterized in that the consumer (18) is additionally protected by at least one electronic fuse (34).
Electrical on-board network (16) according to one of the preceding claims, characterized in that an error entry is generated in a storage device (38) of the electronic computing device (20) before the opening of the disconnect switch device (24).
Electrical system (16) according to Claim 6 , characterized in that the electronic computing device (20) has a communication device (40) and is designed to transmit the error entry to a device external to the electronic computing device (20).
Electrical on-board network (16) according to one of the preceding claims, characterized in that, during driving operation of the motor vehicle (10), the electronic computing device (20) is designed to close the opened disconnect switch device (24) again.
Electrical on-board network (16) according to one of the preceding claims, characterized in that the electronic computing device (20) is designed to open the disconnect switch device (24) only when at least one predetermined threshold value for the overload is exceeded.
Method for operating an electrical on-board network (16) according to one of the Claims 1 until 9 , comprising the steps: - providing the at least partially fuseless, in particular fuseless, upstream distribution board (22); - detecting an overload at the consumer (18) by means of the electronic computing device (20); - generating a control signal (26) to open the disconnect switch device (24) by means of the electronic computing device (20); and - opening the disconnect switch device (24) depending on the control signal (26).

Description

The following invention relates to an electrical system for a motor vehicle that is at least partially electrically powered, according to claim 1. Furthermore, the invention relates to a corresponding method for operating such an electrical system. Electrical components in a vehicle's electrical system and their power lines are typically protected from overload in the event of a short circuit by fuses and/or electronic fuses (eFuses). These fuses and/or eFuses can be cascaded in single or multiple configurations to create a sub-distribution panel consisting of individual power distribution units. As a rule, each supply line is protected by a fuse appropriate to its cross-section, since a short circuit can never be completely ruled out due to environmental conditions, crashes, misuse, or other unforeseen events. Additionally, electrochemical energy storage devices with a corresponding disconnect switch are installed in vehicle electrical systems. For systems with integrated sub-distribution boards, a fuse must be installed in the so-called upstream distribution board, and several fuses must be installed in the sub-distribution board for each line. This typically results in a very large upstream distribution board, leading to increased costs and space requirements. Furthermore, serviceability must be considered, and selectivity must be ensured, especially since the sub-distribution board fuses must trip before the upstream fuses in all operating states; otherwise, the entire power distribution branch shuts down, and diagnostics are possible. Simply omitting the fuse can lead to a short circuit in the line, connector, or sub-distribution board causing the battery disconnect switch to trip, particularly in the case of low-resistance short circuits. Alternatively, in the case of medium- or high-resistance short circuits, a thermal event can occur because the resulting short-circuit current overloads the sub-distribution line but does not trip the battery disconnect switch. Such short circuits are usually rare, as the main power supply is generally protected from environmental influences, misuse and crashes; nevertheless, protecting lines is state of the art. The DE 10 2021 208 257 A1 relates to a method for operating an on-board electrical system that has at least one safety-relevant consumer, wherein a first electrical quantity of at least one safety-relevant consumer is predicted, the predicted first electrical quantity is compared with an associated quantity of the on-board electrical system as a second electrical quantity, and if a restriction of the operation of the on-board electrical system is detected based on the comparison, at least one countermeasure is initiated. The object of the present invention is to provide an electrical on-board network and a method by which a more space-efficient electrical on-board network can be provided. This problem is solved by an electrical on-board network and by a method according to the independent claims. Advantageous embodiments are specified in the dependent claims. One aspect of the invention relates to an electrical system for a motor vehicle that is at least partially electrically powered, comprising at least one electrical energy storage device for providing electrical energy to at least one consumer of the electrical system, wherein the at least one consumer is electrically coupled to the electrical energy storage device via at least one upstream distribution board, and wherein the electrical energy storage device comprises a disconnect switch device for disconnecting an electrical connection to the upstream distribution board and an electronic computing device for controlling the disconnect switch device. It is provided that the upstream distribution board is provided without fuses, and the electronic computing device is additionally designed to determine an overload condition at the upstream distribution board and, depending on a certain overload, the electronic computing device generates a control signal to open the disconnect switch device. In particular, this saves installation space, as the necessary fuses in the upstream distribution board are provided by a corresponding diagnostic mechanism within the electrical energy storage system, specifically within its electronic control unit. This mechanism detects an overload condition and can open the disconnect switch even at low loads. Specifically, the shutdown or opening can be activated only in certain vehicle states to ensure full power is available in other operating conditions. The electronic computing unit can be configured as a battery management system for the electrical energy storage device. A battery management system is an electronic control and monitoring unit for electrical energy storage devices, particularly lithium-ion batteries. It monitors and regulates various parameters of the electrical energy storage device, such as cell voltage, cell temperature, charging and discharging processes, f