US-20260124925-A1 - Battery Management System and Vehicle

Abstract

A battery management system and a vehicle are disclosed. The battery management system includes (i) a first terminal connected to a high-voltage battery, (ii) a second terminal connected to an electronic control unit, (iii) an electrical isolation circuit configured to receive a first current from the electronic control unit via the second terminal, (iv) a current sensing unit configured to sense a second current output by the electrical isolation circuit and generate a disconnect signal in response to the second current exceeding a first threshold value, and (v) a battery disconnect unit configured to disconnect the high-voltage battery from a load connected to the high-voltage battery in response to the disconnect signal. The electrical isolation circuit includes a photoelectric coupling circuit.

Inventors

• Xiaofei Qiu

Assignees

• ROBERT BOSCH GMBH

Dates

Publication Date

20260507

Application Date

20251102

Priority Date

20241104

Claims (8)

1. 1 . A battery management system, comprising: a first terminal connected to a high-voltage battery; a second terminal connected to an electronic control unit; an electrical isolation circuit configured to receive a first current from the electronic control unit via the second terminal; a current sensing unit configured to sense a second current output by the electrical isolation circuit and generate a disconnect signal in response to the second current exceeding a first threshold value; and a battery disconnect unit configured to disconnect the high-voltage battery from a load connected to the high-voltage battery in response to the disconnect signal, wherein the electrical isolation circuit comprises a photoelectric coupling circuit.
2. 2 . The battery management system according to claim 1 , wherein the input end of the photoelectric coupling circuit is connected to the second terminal, and the output end of the photoelectric coupling circuit is connected to the current sensing unit.
3. 3 . The battery management system according to claim 1 , wherein the photoelectric coupling circuit comprises a light-emitting diode and a photosensitive element that are optically coupled to each other.
4. 4 . The battery management system according to claim 3 , wherein the photosensitive element comprises at least one of the following: a photoresistor, a photodiode, a phototriode, and a photocell.
5. 5 . The battery management system according to claim 3 , wherein the electronic control unit applies the first current to the light-emitting diode via the second terminal in the event of a crash; in response to the first current being applied by the electronic control unit, the light-emitting diode emits a first light; and in response to the first light being emitted by the light-emitting diode, a resistance state of the photosensitive element changes.
6. 6 . The battery management system according to claim 5 , wherein, in response to a change in the resistance state of the photosensitive element, the current sensing unit senses the second current exceeding the first threshold value and generates the disconnect signal.
7. 7 . The battery management system according to claim 1 , wherein the current sensing unit comprises a differential current amplifier.
8. 8 . A vehicle, comprising: an electronic control unit; a high-voltage battery; and the battery management system according to claim 1 .

Description

This application claims priority under 35 U.S.C. § 119 to application no. CN 2024 1156 2145.0, filed on Nov. 4, 2024 in China, the disclosure of which is incorporated herein by reference in its entirety. The present disclosure relates to the technical field of battery management, and in particular to a battery management system and a vehicle comprising the battery management system. BACKGROUND In electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in HEVs (PHEVs), a high-voltage (HV) battery powers the electric motor. A crash may damage the high-voltage battery, potentially causing a short circuit and a vehicle fire. To prevent fires in a crash, a battery disconnect airbag is often used to disconnect the high-voltage battery network. However, such airbags are expensive, and repairing them after a crash is also costly. To address these design flaws, a solution has been proposed that uses a differential current amplifier in the battery management system (BMS) to detect the firing current as an input and disconnect the high-voltage battery. However, in this solution, the electronic control unit (ECU) is affected by the differential current amplifier in the battery management system. SUMMARY The present disclosure provides a battery management system and a vehicle comprising such a battery management system to prevent a differential current amplifier in the battery management system from affecting an electronic control unit. Examples of the present disclosure provide a battery management system comprising: a first terminal connected to a high-voltage battery; a second terminal connected to an electronic control unit; an electrical isolation circuit configured to receive a first current from the electronic control unit via the second terminal; a current sensing unit configured to sense a second current output by the electrical isolation circuit and generate a disconnect signal in response to the second current exceeding a first threshold value; and a battery disconnect unit configured to disconnect the high-voltage battery from a load connected to the high-voltage battery in response to the disconnect signal, wherein the electrical isolation circuit comprises a photoelectric coupling circuit. Examples of the present disclosure further provide a vehicle, comprising an electronic control unit, a high-voltage battery, and a battery management system according to an example of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic block diagram of a battery management system used in related art for sensing firing current; FIG. 2 is a schematic circuit diagram of a battery management system used in related art for sensing firing current; FIG. 3 is a schematic block diagram of a battery management system according to an example of the present disclosure; FIG. 4 is a schematic circuit diagram of an electrical isolation circuit in a battery management system according to an example of the present disclosure. Throughout the several drawings, corresponding reference signs indicate corresponding parts. The elements shown are not necessarily drawn to scale. The configurations depicted are merely examples and should not be construed as limiting the scope of the present disclosure in any way. DETAILED DESCRIPTION The accompanying drawings of the examples of the present disclosure are provided to offer a further understanding of the examples and constitute a part of the Specification. Together with the detailed examples, they are used to explain the present disclosure and are not intended to limit the present disclosure. The above and other features and advantages will become more readily apparent to those skilled in the art through the description of the detailed examples with reference to the accompanying drawings. FIG. 1 is a schematic block diagram of a battery management system sensing firing current in the related art. FIG. 2 is a schematic circuit diagram of a battery management system sensing firing current in the related art. As shown in FIGS. 1 and 2, the sensing resistor in the battery management system is connected between the high side (HS) and the low side (LS) of the electronic control unit, and the differential current amplifier in the battery management system senses the firing current flowing through the sensing resistor. Since the differential current amplifier in the battery management system is directly electrically connected to the electronic control unit, the differential current amplifier will affect the electronic control unit. In addition, there is a ground deviation between the ground GND1 of the electronic control unit and the ground GND2 of the differential current amplifier, which will cause current injection from or to the electronic control unit. Since the input circuit of the battery management system is a high-impedance circuit, the electronic control unit is easily affected by electromagnetic compatibility (EMC), such as bulk current injection (BCI). To