Battery box system and electric equipment

Abstract

The utility model provides a battery box system and electric equipment, and relates to the technical field of storage batteries. The battery box system comprises a plurality of battery boxes, a thermal management system and an auxiliary control unit; the thermal management system is used for cooling the battery box with thermal runaway; and the auxiliary control unit is connected with each battery box and is used for controlling any battery box to provide voltage for the thermal management system. As the auxiliary control unit is arranged and is connected with each battery box, the power supply battery box can be dynamically selected according to the voltage state of the battery box, and the thermal management system is ensured to obtain stable voltage input all the time. According to the battery box system, system failure caused by insufficient voltage of a thermal management system due to disconnection of high-voltage connection caused by thermal runaway is avoided, and effective cooling treatment on the thermal runaway battery box is realized.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more particularly to a battery box system and electrical equipment. Background Technology

[0002] With the development of the new energy industry, more and more vehicles are using lithium batteries as their power source, especially the electric heavy-duty truck industry, which has seen rapid growth recently. To quickly adapt to more heavy-duty truck models, the battery systems in the heavy-duty truck industry generally use several standard battery boxes connected in series and parallel to form one or more branch circuits. Because the transportation industry requires vehicles to have a certain driving range, battery companies are constantly increasing the system capacity to meet customer demands. Some, in order to accommodate more capacity within a limited space, have even switched from conventional lithium iron phosphate cells to ternary lithium cells with higher energy density. Since this battery system generally has a higher capacity, it is prone to thermal runaway. When a cell in the battery box experiences thermal runaway, it generates a large amount of heat, which continuously spreads to surrounding cells. If the heat generated by this cell is not dissipated in time, it will cause heat to spread throughout the entire battery box, potentially leading to a fire in the entire battery system. In existing technologies, water cooling systems are used to cool down battery boxes that have experienced thermal runaway through water circulation. However, when a fire occurs, the BMS (Battery Management System) will disconnect all high-voltage circuits. Since the high-voltage circuits are disconnected, the water cooling system of the entire battery system will also lose power supply and thus cannot work, and cannot remove heat, leading to a thermal runaway event.

[0003] Therefore, there is an urgent need to provide a battery box system or electrical equipment that can cool down the battery box that has experienced thermal runaway in a timely manner after the high-voltage circuit is broken, thereby improving the product safety performance. Utility Model Content

[0004] This application provides a battery box system and electrical equipment to solve the problem that a break in the high-voltage circuit will cause the water cooling system of the entire battery system to lose power and thus become inoperable. This allows the battery box that has experienced thermal runaway to be cooled down in a timely manner after the high-voltage circuit is broken, thereby improving the product's safety performance.

[0005] In a first aspect, this application provides a battery box system, including multiple battery boxes, a thermal management system, and an auxiliary control unit; the thermal management system is used to cool down a battery box that has experienced thermal runaway; the auxiliary control unit is connected to each battery box and is used to control any battery box to provide voltage to the thermal management system.

[0006] Through the above-described solution, the thermal management system can cool down battery boxes experiencing thermal runaway, preventing the runaway from spreading to other battery boxes or causing more serious safety issues such as fire or explosion. The auxiliary control unit can dynamically select the power supply battery box based on its voltage status, ensuring the thermal management system always receives a stable voltage input. This battery box system avoids system failure caused by insufficient voltage in the thermal management system due to the disconnection of the high-voltage connection during thermal runaway, thus achieving effective cooling of the thermally runaway battery box.

[0007] In one possible design, the auxiliary control unit includes a control box and an auxiliary converter. The control box is connected to each battery box. The input of the auxiliary converter is connected to the control box, and the output of the auxiliary converter is connected to the thermal management system. The auxiliary converter is used to boost the voltage output by the control box so that the voltage output by the control box reaches a first voltage threshold.

[0008] Through the above scheme, the auxiliary converter boosts the voltage output from the control box to the first voltage threshold, ensuring that the thermal management system always receives a stable voltage input. Even if the voltage of one battery box is insufficient, the auxiliary converter can still boost it using the voltage from other battery boxes, ensuring the normal operation of the thermal management system. This redundancy design further enhances the system's fault tolerance.

[0009] In one possible design, the input terminal of the control box is provided with multiple control branches, which are respectively connected to multiple battery boxes; each control branch has a positive terminal and a negative terminal; a diode and a battery box relay of the corresponding battery box are connected in series in the positive terminal, and the battery box relay is used to control the on and off of the corresponding control branch; a fuse is connected in series in the negative terminal.

[0010] In this design, each control branch corresponds to a battery box, and the on / off state of each branch is independently controlled by a battery box relay. This design allows the system to flexibly select the power supply battery box, optimize voltage management, and facilitate maintenance or replacement of individual battery boxes. By distributing the current through multiple control branches, the current load on individual branches is reduced, lowering heat loss and voltage drop caused by excessive current, thereby improving the overall system efficiency. The battery box relay can dynamically control the connection status of the corresponding battery box according to system requirements, ensuring that the thermal management system always receives a stable voltage input, further optimizing system performance. By integrating diodes, relays, and fuses into each control branch, the system achieves functional centralization, reducing complex external protection circuits and control logic, and lowering system complexity.

[0011] In one possible design, an external power supply unit is also included, which is connected to the auxiliary control unit and is used to supply power to the auxiliary control unit.

[0012] Through the above solution, the external power supply unit provides a stable power supply to the auxiliary control unit, enabling it to continuously monitor and control the battery pack's status. This design significantly enhances the system's stability and reliability, optimizes its overall performance, reduces its complexity and cost, and provides strong support for the efficient operation and thermal management of the battery system.

[0013] In one possible design, multiple battery boxes are divided into at least two battery branches, and when each battery branch has at least two battery boxes, the battery boxes in each battery branch are connected in series.

[0014] The above scheme divides the battery pack into multiple branches, each of which can be managed independently. This allows for the timely disconnection of the branch containing a battery pack experiencing thermal runaway, preventing the fault from spreading to other branches or devices and further improving system safety. Even if a battery pack in one branch fails, other branches can continue to supply power. This redundancy design significantly improves the system's fault tolerance and reduces the risk of system failure due to a single battery pack failure.

[0015] In one possible design, a high-voltage box unit is also included, with each battery branch connected to the input of the high-voltage box unit and the output of the high-voltage box unit connected to the thermal management system.

[0016] Through the above scheme, the high-voltage box unit, as a key connection component between the battery branch and the thermal management system, can centrally manage the electrical connections and protection functions of the battery branch. The high-voltage box unit supports multiple power supply methods (such as AC220V or DC24V), flexibly adapting to different application scenarios and electrical requirements. This flexibility allows the system to be better integrated into different energy storage or electric vehicle architectures. By introducing the high-voltage box unit as the connection component between the battery branch and the thermal management system, this design significantly improves the system's centralized management capabilities, safety, and reliability, while optimizing the voltage input and operating efficiency of the thermal management system.

[0017] In one possible design, the thermal management system includes a water-cooled unit with a cooling function, and the output of the high-pressure unit is connected to the water-cooled unit.

[0018] Through the above scheme, the water-cooled unit can perform compression refrigeration, realize heat transfer, and efficiently dissipate the heat generated by the battery box to the outside. By connecting the output end of the high-voltage box unit to the water-cooled unit, safety problems caused by overheating of the battery box, such as thermal runaway, can be effectively prevented. This design significantly improves the operating efficiency and reliability of the thermal management system.

[0019] In one possible design, each battery branch is connected in parallel to the input of the high-voltage box unit; each battery branch is also connected to a charging device, which is connected in parallel to the output of the high-voltage box unit; a water-cooled unit is connected between the output of the high-voltage box unit and the charging device.

[0020] By employing the above scheme, multiple battery branches are connected in parallel to the input terminal of the high-voltage box unit, enabling centralized management of the voltage and current output of each battery branch. Each battery branch is independently connected to the high-voltage box unit, ensuring that if one branch fails, the others continue to operate normally, thus improving the system's fault tolerance. Furthermore, the output terminals of the charging equipment and the high-voltage box unit are not simultaneously closed; therefore, connecting the water-cooled unit across the output terminal of the high-voltage box unit and the charging equipment ensures that the water-cooled unit remains powered even during charging. This guarantees the stability and reliability of the thermal management system.

[0021] In one possible design, the high-voltage box unit includes a first input terminal, a first output terminal, a charging terminal, branch relays corresponding to multiple battery branches, a main positive relay, a water-cooling relay, and a charging relay corresponding to multiple battery branches; the first input terminal is connected to the first terminal of each of the multiple branch relays, and the multiple branch relays are connected in parallel; the second terminal of the multiple branch relays is connected to the first terminal of the main positive relay and the first terminal of the charging relay; the second terminal of the main positive relay is connected to the first terminal of the first output terminal, the first terminal of the water-cooling relay, and the first terminal of the charging terminal; the second terminal of the charging relay is connected to the first terminal of the first output terminal, the first terminal of the water-cooling unit relay, and the first terminal of the charging terminal; the second terminal of the water-cooling relay is electrically connected to the water-cooling unit for controlling the on / off state of the water-cooling unit.

[0022] In this design, each battery branch is connected to the first input terminal of the high-voltage box unit via an independent branch relay. This allows for independent control of each branch; for example, if a branch fails, it can be disconnected without affecting the operation of other branches. The main positive relay centrally manages the outputs of all branch relays and connects to the first output terminal, the water-cooling relay, and the charging terminal. This centralized management simplifies circuit design while ensuring overall system efficiency. The charging relay allows for independent control of the charging process, ensuring the charging equipment can be safely connected or disconnected when needed, further improving system flexibility. Connecting the water-cooling unit across the output terminal of the high-voltage box unit and the charging equipment ensures that the water-cooling unit remains powered even during charging, thus guaranteeing the stability and reliability of the thermal management system.

[0023] Secondly, this application provides an electrical device including a battery box system as described above.

[0024] The beneficial effects provided in the second aspect and its various possible designs can be found in the first aspect and its various possible implementations, and will not be repeated here.

[0025] The above description is merely an overview of the technical solutions of the embodiments of this application. In order to better understand the technical means of the embodiments of this application and to implement them in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the embodiments of this application more obvious and understandable, specific implementation methods of this application are described below. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of a battery box system provided in one embodiment of this application.

[0028] Figure 2 This is a flowchart of a control method for a battery management system provided in one embodiment of this application.

[0029] Figure 3 This is a flowchart of a control method for a battery management system provided in one embodiment of this application.

[0030] Figure 4 This is a flowchart of a control method for a battery management system provided in one embodiment of this application.

[0031] Figure 5 This is an architecture diagram of a battery management system provided in one embodiment of this application.

[0032] Figure 6 This is a schematic diagram of the internal structure of the control box provided in one embodiment of this application.

[0033] Figure 7 This is a schematic diagram showing the connection of the main internal components of the high-voltage box provided in one embodiment of this application.

[0034] Figure 8 This is a partial flowchart of the control method of a battery management system provided in another embodiment of this application.

[0035] Figure 9 This is a partial flowchart of the control method of the pool management system provided in another embodiment of this application.

[0036] Figure 10This is a schematic diagram of the process for entering the forced cooling mode provided in another embodiment of this application.

[0037] Figure 11 This is a partial flowchart of controlling the shutdown of the water-cooled unit to enter the auxiliary control mode, provided in another embodiment of this application.

[0038] Figure 12 This is a flowchart illustrating the process of entering auxiliary control mode as provided in another embodiment of this application.

[0039] Figure 13 This is a flowchart of entering the low-pressure cooling mode provided in another embodiment of this application. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims and drawings of this application are intended to cover non-exclusive inclusion.

[0042] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of the phrase "embodiment" in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0043] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists, A and B exist simultaneously, or B exists. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0044] The directional terms appearing in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. For example, in the description of this application, the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0045] Furthermore, the terms "first," "second," etc., in the specification and claims of this application or in the aforementioned drawings are used to distinguish different objects rather than to describe a specific order, and may explicitly or implicitly include one or more of the features.

[0046] In the description of this application, unless otherwise stated, "multiple" means two or more (including two), and similarly, "multiple groups" means two or more (including two groups).

[0047] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, "connection" or "linkage" in mechanical structures can refer to a physical connection, such as a fixed connection, for example, a connection fixed by a partition, such as a connection fixed by screws, bolts, or other partitions; a physical connection can also be a detachable connection, such as a snap-fit ​​or interlocking connection; a physical connection can also be an integral connection, such as a connection formed by welding, bonding, or integral molding. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. In circuit structures, "connection" or "linkage" can refer not only to a physical connection but also to an electrical connection or a signal connection. For example, it can be a direct connection, i.e., a physical connection, or an indirect connection through at least one intermediate element, as long as the circuit is connected; it can also refer to the internal connection of two elements. A signal connection can refer not only to a signal connection through a circuit but also to a signal connection through a medium, such as radio waves. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0048] As the background technology shows, in the current battery box system or electrical equipment, when a fire occurs, the BMS (Battery Management System) will disconnect all high-voltage circuits. Because the high-voltage circuits are disconnected, the water cooling system of the entire battery system will also lose power supply and thus cannot work, and cannot dissipate heat, leading to thermal runaway events.

[0049] In view of this, embodiments of this application provide a battery box system or electrical device, including multiple battery boxes, a thermal management system, and an auxiliary control unit. The thermal management system is connected to the auxiliary control unit. Because of the auxiliary control unit, even after the high-voltage circuit is broken, any of the battery boxes can be controlled in a timely manner to provide voltage to the thermal management system to cool down the battery box that has experienced thermal runaway, thereby improving the product safety performance.

[0050] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0051] A BMS (Battery Management System) is used to control and manage the various internal units of a battery box system. Figure 1 This is a schematic diagram of a battery box system provided in this embodiment. Please refer to it. Figure 1 This application provides a battery box system, including multiple battery boxes, a thermal management system 702, and an auxiliary control unit 703; the thermal management system 703 is used to cool down a battery box that has experienced thermal runaway; the auxiliary control unit 703 is connected to each battery box and is used to control any battery box to provide voltage to the thermal management system.

[0052] The thermal management system 702 can cool down battery boxes experiencing thermal runaway, preventing the runaway from spreading to other battery boxes or causing more serious safety problems such as fire or explosion. The auxiliary control unit 703 can dynamically select which battery boxes to supply power to the thermal management system 702 based on their voltage status, ensuring that the thermal management system 702 always receives a stable voltage input. This battery box system avoids system failure caused by the thermal management system 702 losing power due to the disconnection of the high-voltage connection during thermal runaway, thus achieving effective cooling of the thermally runaway battery boxes.

[0053] In this embodiment, the auxiliary control unit 703 includes a control box and an auxiliary converter. The control box is connected to each battery box. The input terminal of the auxiliary converter is connected to the control box, and the output terminal of the auxiliary converter is connected to the thermal management system 702. The auxiliary converter is used to boost the voltage output by the control box so that the voltage output by the control box reaches a first voltage threshold.

[0054] Through the above embodiments, the auxiliary converter boosts the voltage output from the control box to the first voltage threshold, ensuring that the thermal management system 702 always receives a stable voltage input. Even if the voltage of a certain battery box is insufficient, the auxiliary converter can still boost it using the voltage of other battery boxes, ensuring that the thermal management system 702 can operate normally. This redundancy design further enhances the system's fault tolerance.

[0055] In this embodiment, the input terminal of the control box is provided with multiple control branches, which are respectively connected to multiple battery boxes; each control branch has a positive terminal and a negative terminal; a diode and a battery box relay of the corresponding battery box are connected in series in the positive terminal, and the battery box relay is used to control the on and off of the corresponding control branch; a fuse is connected in series in the negative terminal.

[0056] In the above embodiments, each control branch corresponds to a battery box, and the on / off state of each branch is independently controlled by a battery box relay. This design allows the system to flexibly select the power supply battery box, optimize voltage management, and facilitate maintenance or replacement of individual battery boxes. By distributing the current through multiple control branches, the current load of individual branches is reduced, lowering heat loss and voltage drop caused by excessive current, thereby improving the overall efficiency of the system. The battery box relay can dynamically control the connection status of the corresponding battery box according to system requirements, ensuring that the thermal management system 702 always receives a stable voltage input, further optimizing system performance. By integrating diodes, relays, and fuses in each control branch, the system achieves functional centralization, reducing complex external protection circuits and control logic, and lowering system complexity.

[0057] In this embodiment, an external power supply unit is also included. The auxiliary control unit 703 is connected to the external power supply unit, which is used to supply power to the auxiliary control unit 703.

[0058] Through the above embodiments, the external power supply unit provides a stable power supply to the auxiliary control unit 703, enabling it to continuously monitor and control the status of the battery pack. This design significantly enhances the stability and reliability of the system, optimizes the overall system performance, reduces the system's complexity and cost, and provides strong support for the efficient operation and thermal management of the battery system.

[0059] In this embodiment, multiple battery boxes are divided into at least two battery branches. When each group of battery branches has at least two battery boxes, the battery boxes in each group of battery branches are connected in series.

[0060] Through the above embodiments, the battery box is divided into multiple branches, and the battery boxes in each branch can be managed independently. The branch containing a battery box experiencing thermal runaway can be disconnected promptly, preventing the fault from spreading to other branches or equipment, further improving system safety. Even if a battery box in one branch fails, other branches can continue to supply power. This redundancy design significantly improves the system's fault tolerance and reduces the risk of system failure due to a single battery box failure.

[0061] In this embodiment, a high-voltage box unit is also included. Each battery branch is connected to the input terminal of the high-voltage box unit, and the output terminal of the high-voltage box unit is connected to the thermal management system 702.

[0062] Through the above embodiments, the high-voltage box unit, as a key connection component between the battery branch and the thermal management system 702, can centrally manage the electrical connections and protection functions of the battery branch. The high-voltage box unit supports multiple power supply methods (such as AC220V or DC24V), flexibly adapting to different application scenarios and electrical requirements. This flexibility allows the system to be better integrated into different energy storage or electric vehicle architectures. By introducing the high-voltage box unit as the connection component between the battery branch and the thermal management system 702, this design significantly improves the system's centralized management capabilities, safety, and reliability, while optimizing the voltage input and operating efficiency of the thermal management system 702.

[0063] In this embodiment, the thermal management system 702 includes a water-cooled unit with a cooling function, and the output end of the high-pressure box unit is connected to the water-cooled unit.

[0064] Through the above embodiments, the water-cooled unit can perform compression refrigeration, realize heat transfer, and efficiently dissipate the heat generated by the battery box to the outside. By connecting the output end of the high-voltage box unit to the water-cooled unit, safety problems caused by overheating of the battery box, such as thermal runaway, can be effectively prevented. This design significantly improves the operating efficiency and reliability of the thermal management system 702.

[0065] In this embodiment, each battery branch is connected in parallel to the input terminal of the high-voltage box unit; each battery branch is also connected to a charging device, which is connected in parallel to the output terminal of the high-voltage box unit; a water-cooled unit is connected across the output terminal of the high-voltage box unit and the charging device (see reference). Figure 7 ).

[0066] Through the above embodiments, by connecting multiple battery branches in parallel to each other and connecting them to the input terminal of the high-voltage box unit, the system can centrally manage the voltage and current output of the battery branches. Each battery branch is independently connected to the high-voltage box unit, so when one branch fails, the other branches can still operate normally, thereby improving the system's fault tolerance. Furthermore, the output terminals of the charging equipment and the high-voltage box unit are not simultaneously closed; therefore, by connecting the water-cooled unit across the output terminal of the high-voltage box unit and the charging equipment, it is ensured that the water-cooled unit can be powered even during charging. This ensures the stability and reliability of the thermal management system 702.

[0067] In this embodiment, the high-voltage box unit includes a first input terminal, a first output terminal, a charging terminal, a branch relay, a main positive relay, a water-cooling relay, and a charging relay corresponding to multiple battery branches. The first input terminal is connected to the first terminals of the multiple branch relays, which are connected in parallel. The second terminals of the multiple branch relays are connected to the first terminals of the main positive relay and the charging relay. The second terminal of the main positive relay is connected to the first terminal of the first output terminal, the first terminal of the water-cooling relay, and the first terminal of the charging terminal. The second terminal of the charging relay is connected to the first terminal of the first output terminal, the first terminal of the water-cooling unit relay, and the first terminal of the charging terminal. The second terminal of the water-cooling relay is electrically connected to the water-cooling unit for controlling the on / off state of the water-cooling unit (see reference). Figure 7 ).

[0068] In the above embodiments, each battery branch is connected to the first input terminal of the high-voltage box unit via an independent branch relay. This design allows the system to control each branch independently; for example, if a branch fails, it can be disconnected without affecting the operation of other branches. The main positive relay centrally manages the outputs of all branch relays and connects to the first output terminal, the water-cooling relay, and the charging terminal. This centralized management simplifies circuit design while ensuring the overall operating efficiency of the system. The charging relay allows the system to independently control the charging process, ensuring that the charging equipment can be safely connected or disconnected when needed, further improving the system's flexibility. Connecting the water-cooling unit across the output terminal of the high-voltage box unit and the charging equipment ensures that the water-cooling unit can be powered even during charging. This guarantees the stability and reliability of the thermal management system 702.

[0069] This embodiment also provides an electrical device, including any of the above-described battery box systems.

[0070] Figure 2 This is a flowchart of the control method for the battery management system provided in this embodiment. Please refer to it. Figure 2 This embodiment provides a control method for a battery management system, including:

[0071] Step 1: Locate the target battery box in the battery system where thermal runaway has occurred. The battery system includes a target branch and a discharge branch. The target branch contains the target battery box, and the discharge branch is the battery branch that has not experienced thermal runaway.

[0072] By locating and disconnecting the target branch experiencing thermal runaway from the thermal management system, it is possible to effectively prevent the thermally runaway battery pack from damaging the thermal management system or triggering a wider thermal runaway event.

[0073] Step 2: Disconnect the target branch from the thermal management system.

[0074] This isolation measure prevents the heat from thermal runaway from being transferred to the thermal management system or other battery compartments, thereby reducing the safety risk of the entire battery system. Thermal runaway is a dangerous situation that can trigger a chain reaction. By promptly identifying and isolating the target battery compartment, the spread of thermal runaway from one battery compartment to others can be prevented, avoiding a complete loss of control of the entire battery system and significantly improving the safety of the battery system.

[0075] Step 3: Control other battery boxes that have not sent thermal runaway signals to provide voltage to the thermal management system so that the thermal management system can cool down the battery box corresponding to the target branch.

[0076] When thermal runaway occurs, the battery box that experienced thermal runaway needs to be cooled down. By controlling other battery boxes that have not experienced thermal runaway to provide voltage to the thermal management system, the thermal management system can cool down the battery box corresponding to the target branch. This can handle thermal runaway events in a timely manner, improve thermal management efficiency, and enhance product safety performance.

[0077] Figure 3 This is a flowchart of the control method for the battery management system provided in this embodiment. Please refer to it. Figure 3 In some embodiments, controlling other battery boxes that have not experienced thermal runaway to provide voltage to the thermal management system, so that the thermal management system can cool down the battery box corresponding to the target branch, includes: controlling at least two battery boxes in other battery boxes to be connected in series to form a branch to be operated; when the output voltage of the branch to be operated is greater than or equal to a first voltage threshold, controlling the branch to be operated to provide voltage to the thermal management system, so that the thermal management system can cool down the battery box corresponding to the target branch. The thermal management system cooling down the battery box corresponding to the target branch includes: controlling the water-cooled unit in the thermal management system to cool down the target branch at a first preset power, wherein cooling down the branch to be operated includes cooling down the battery box in the target branch where thermal runaway has occurred; the first preset power is used to meet the compression and refrigeration function of the water-cooled unit.

[0078] Through the above embodiments, by controlling at least two battery boxes in other battery boxes that have not experienced thermal runaway to be connected in series to form a working branch, the system can dynamically adjust the branch combination according to actual needs. This flexibility allows the system to quickly reconfigure the branch when some battery boxes fail, ensuring the normal operation of the thermal management system without relying on a fixed branch layout. The thermal management system can continue to be powered by combinations of other battery boxes, thereby cooling the battery box that has experienced thermal runaway, improving product safety. By setting a first voltage threshold, the working branch is only allowed to supply power to the thermal management system when its output voltage reaches or exceeds this threshold. This voltage control mechanism ensures that the thermal management system operates at an appropriate voltage, avoiding inefficiency or equipment damage due to insufficient or excessive voltage. The thermal management system cools the target branch with a first preset power, which is specifically designed to meet the compression and refrigeration function of the water-cooled unit, thus enabling better cooling of the target battery box. This targeted cooling method not only effectively reduces the temperature of the thermally runaway battery box but also avoids over-cooling or under-cooling, improving the efficiency and accuracy of thermal management.

[0079] In some embodiments, controlling at least two battery boxes in other battery boxes to be connected in series to obtain a working branch includes: when the working branch does not include all other battery boxes, and the output voltage of the working branch is less than a first voltage threshold, determining a working battery box, wherein the working battery box is the battery box with the highest output voltage among the other battery boxes; controlling the working battery box to provide voltage to the thermal management system so that the thermal management system can perform cooling treatment on the battery box corresponding to the target branch.

[0080] Through the above embodiments, when the branch to be operated does not contain any other battery boxes and its output voltage is lower than a first voltage threshold, the battery box with the highest output voltage is selected to power the thermal management system. This dynamic adjustment mechanism ensures that the thermal management system always receives sufficient voltage, avoiding thermal management function failure due to insufficient voltage. Even if some battery boxes have low output voltage or are faulty, the system can still maintain the function of the thermal management system by selecting the best-performing battery box, thereby significantly improving the system's fault tolerance. By selecting the battery box with the highest output voltage as the working battery box to power the thermal management system, the thermal management system can accurately provide the required voltage according to actual needs, avoiding unnecessary energy consumption.

[0081] In some embodiments, controlling at least two battery boxes in other battery boxes to be connected in series to obtain a branch to be worked includes: when the branch to be worked is a discharge branch and the output voltage of the discharge branch is less than a first voltage threshold, determining a working battery box, wherein the working battery box is the battery box with the highest output voltage among the other battery boxes.

[0082] Through the above embodiments, when the branch to be operated is a discharge branch and its output voltage is lower than a first voltage threshold, the operating battery box with the highest output voltage is selected to power the thermal management system. By dynamically selecting the operating battery box to power the thermal management system, the system can continuously cool the target branch, preventing further thermal runaway and thus improving system safety.

[0083] Figure 4 This is a flowchart of the control method for the battery management system provided in this embodiment. Please refer to it. Figure 4 In this embodiment, controlling other battery boxes that have not experienced thermal runaway to provide voltage to the thermal management system so that the thermal management system can cool down the battery box corresponding to the target branch, further includes the steps of: determining a working battery box from the other battery boxes, wherein the working battery box is the battery box with the highest output voltage among the other battery boxes; and controlling the working battery box to provide voltage to the thermal management system when the voltage of the working battery box is greater than or equal to a first voltage threshold so that the thermal management system can cool down the battery box corresponding to the target branch; wherein the thermal management system cools down the battery box corresponding to the target branch by controlling the water-cooled unit in the thermal management system to cool down the target branch with a first preset power, wherein cooling down the target branch includes cooling down the battery box in the target branch that has experienced thermal runaway; the first preset power is used to meet the compression and refrigeration function of the water-cooled unit.

[0084] Through the above embodiments, by selecting the battery box with the highest output voltage from among other battery boxes that have not experienced thermal runaway as the working battery box, the system can ensure a stable voltage input to the thermal management system. This selection mechanism avoids the risk of the thermal management system failing to operate normally due to insufficient voltage in individual battery boxes. Even if some battery boxes experience performance degradation or failure, the system can still maintain thermal management functions by selecting the best-performing battery box, significantly improving the system's fault tolerance. The working battery box is only allowed to supply power to the thermal management system when its voltage is greater than or equal to a first voltage threshold. This threshold control mechanism avoids unnecessary energy consumption while ensuring the efficient operation of the thermal management system. By using the working battery box to provide voltage to the thermal management system in a timely manner, thermal runaway events can be handled promptly, improving thermal management efficiency and reducing energy waste.

[0085] In some embodiments, the method further includes: when the output voltage of the working battery box is greater than the cutoff voltage and less than the first voltage threshold, increasing the voltage of the working battery box to be greater than the first voltage threshold so that the thermal management system can cool down the battery box corresponding to the target branch.

[0086] The above scheme establishes the cutoff voltage as the battery's minimum operating voltage. When the battery voltage falls below this value, continued discharge can cause irreversible damage to the battery's internal chemical substances, such as structural destruction of electrode materials and electrolyte decomposition. Voltage boosting is only possible when the operating battery pack's voltage exceeds its cutoff voltage, thus ensuring the battery pack's lifespan. By boosting the operating battery pack's voltage to the threshold required by the thermal management system, the thermal management system (such as a water-cooled unit) can operate at its first preset power, achieving efficient cooling of the thermally runaway battery pack in the target branch. This voltage boosting method avoids thermal management failure due to insufficient output voltage from the operating battery pack, ensuring the stability and reliability of the thermal management system.

[0087] In some embodiments, the method further includes: when the voltage value of the working battery box is lower than the cutoff voltage of the working battery box, controlling the working battery box to stop supplying voltage to the thermal management system and re-determining the working battery box; wherein the cutoff voltage is the minimum operating voltage of the working battery box.

[0088] By employing the above-described method, stopping discharge when the voltage drops below the cutoff voltage can effectively prevent such damage and extend battery life. Continuing to supply power when the working battery box voltage is below the cutoff voltage may cause the thermal management system to malfunction or even lead to equipment failure. Timely switching of the battery box ensures that the thermal management system always receives a stable voltage input, preventing system failure due to insufficient voltage. Timely re-determination of the working battery box allows the thermal management system to promptly cool down any battery box experiencing thermal runaway.

[0089] In some embodiments, the method further includes: when the output voltage of each battery box is less than the cutoff voltage, controlling the vehicle battery to provide voltage to the water-cooled unit so that the water-cooled unit performs cooling at a second preset power, wherein the second preset power is less than the first preset power, and the second preset power is used to satisfy the cooling function of the water-cooled unit starting the condenser fan and water pump.

[0090] With the above solution, even in extreme conditions (when all battery box voltages are below the cutoff voltage), the system can still provide a minimum cooling function to the water-cooled unit through the vehicle's battery, thereby effectively reducing the temperature of the thermal runaway battery box and minimizing the risk of thermal runaway propagation. By maintaining the basic operation of the water-cooled unit, equipment damage caused by high temperatures can be prevented, improving the overall safety of the system.

[0091] In some embodiments, the method further includes: controlling the water-cooled unit to standby mode when the temperature of the thermally runaway battery box is less than or equal to a first temperature threshold.

[0092] The first threshold temperature T1 is the safe temperature of the battery compartment. In other words, if the temperature of the battery compartment is below this value, it can be confirmed that the battery compartment is in a safe state and thermal runaway will never occur. For example, the first threshold temperature can be 50℃.

[0093] Water-cooled units reduce wear and aging of mechanical components when in standby mode. By operating the cooling system only when necessary, the lifespan of critical components such as water pumps and fans can be extended. Entering standby mode when the battery compartment temperature drops to a safe level avoids overcooling. This design ensures the battery system operates within a safe temperature range while preventing temperature anomalies caused by cooling system malfunctions or misoperation. By reducing unnecessary cooling operation time, the system can significantly reduce energy consumption. Controlling the water-cooled unit to standby mode when the battery compartment temperature drops to a safe range significantly improves the system's energy efficiency and intelligence. Simultaneously, it extends equipment life, reduces operating costs, and further enhances system reliability and safety.

[0094] Based on the above embodiments, this application also provides a control device for a battery management system, the control device comprising:

[0095] The positioning unit is used to locate the target battery box in the battery system where thermal runaway has occurred. The battery system includes a target branch and a discharge branch. The target branch contains the target battery box. The discharge branch is the battery branch that has not experienced thermal runaway.

[0096] The disconnection unit is used to disconnect the target branch from the thermal management system.

[0097] The first control unit is used to control other battery boxes that have not experienced thermal runaway to provide voltage to the thermal management system so that the thermal management system can cool down the battery box corresponding to the target branch.

[0098] The first control unit further includes a second control unit, which controls at least two battery boxes in other battery boxes to be connected in series to form a branch to be operated. When the output voltage of the branch to be operated is greater than or equal to a first voltage threshold, the second control unit controls the branch to be operated to provide voltage to the thermal management system, so that the thermal management system can cool the battery box corresponding to the target branch. The cooling of the battery box corresponding to the target branch by the thermal management system includes: controlling the water-cooled unit in the thermal management system to cool the target branch at a first preset power, wherein cooling the branch to be operated includes cooling the battery box in the target branch that has experienced thermal runaway; the first preset power is used to meet the compression and refrigeration function of the water-cooled unit.

[0099] The second control unit is also used to determine the working battery box when the branch to be worked does not include all other battery boxes and the output voltage of the branch to be worked is less than the first voltage threshold. The working battery box is the battery box with the highest output voltage among the other battery boxes. The control unit controls the working battery box to provide voltage to the thermal management system so that the thermal management system can cool down the battery box corresponding to the target branch.

[0100] The second control unit is also used to determine the working battery box when the branch to be worked is a discharge branch and the output voltage of the discharge branch is less than the first voltage threshold. The working battery box is the battery box with the highest output voltage among the other battery boxes.

[0101] The first control unit further includes a third control unit, which is used to determine the working battery box from the other battery boxes. The working battery box is the battery box with the highest output voltage among the other battery boxes. When the voltage of the working battery box is greater than or equal to a first voltage threshold, the control unit controls the working battery box to provide voltage to the thermal management system so that the thermal management system can cool down the battery box corresponding to the target branch. The cooling down of the battery box corresponding to the target branch by the thermal management system includes controlling the water-cooled unit in the thermal management system to cool down the target branch at a first preset power. Cooling down the target branch includes cooling down the battery box in the target branch that has experienced thermal runaway. The first preset power is used to meet the compression and refrigeration function of the water-cooled unit.

[0102] The control device also includes a voltage boosting unit, which is used to boost the voltage of the working battery box to a level greater than the first voltage threshold when the output voltage of the working battery box is greater than the cutoff voltage and less than the first voltage threshold, so that the thermal management system can cool down the battery box corresponding to the target branch. The cutoff voltage is the minimum operating voltage of the working battery box.

[0103] The control device also includes a reset unit, which controls the working battery box to stop supplying voltage to the thermal management system and resets the working battery box when the voltage value of the working battery box is lower than the cutoff voltage of the working battery box.

[0104] The control device also includes a fourth control unit, which controls the vehicle battery to provide voltage to the water-cooled unit when the output voltage of each battery box is less than the cutoff voltage, so that the water-cooled unit can cool at a second preset power, wherein the second preset power is less than the first preset power, and the second preset power is used to meet the cooling function of the water-cooled unit to start the condenser fan and water pump.

[0105] The control device also includes a standby control unit, which is used to control the water-cooled unit to be in standby mode when the temperature of the thermally runaway battery box is less than or equal to a first temperature threshold.

[0106] Since the control device of the battery management system is used to implement its control method, and the method and its beneficial effects have been described in detail in the previous embodiments, this application will not repeat them here.

[0107] Based on the above embodiments, this application also provides a battery system electronic device, including: a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of any of the above control methods.

[0108] This application also provides a computer-readable storage medium storing a computer program executable by an electronic device, which, when run on the electronic device, causes the electronic device to perform the steps of any of the above control methods.

[0109] This application also provides a vehicle, specifically comprising: an electronic device for implementing any of the above control methods; a processor that runs a program, and when the program runs, executes the steps of any of the above control methods on data output from the electronic device; and a storage medium for storing the program, and when the program runs, executes the steps of any of the above control methods on data output from the electronic device.

[0110] Example 1

[0111] Figure 5 This is a diagram of the battery management system architecture provided in this embodiment. Please refer to it. Figure 5 The battery management system architecture includes: a battery box section, where each battery box integrates multiple battery modules and a battery management unit (BMU). To increase the capacity of the battery system, multiple battery branches are typically set up, for example... Figure 1 The system has two battery branches, with each branch consisting of four battery boxes. The two battery branches are connected in parallel, and the four battery boxes in each branch are connected in series. The two branches converge into a high-voltage box, and the high voltage output from the high-voltage box enters the water-cooled unit, the on-board inverter (on-board DC / DC), the on-board charger, the motor controller, etc. (There are usually other high-voltage load components on the vehicle, but these are not the focus of this solution and are not listed here.)

[0112] Water-cooled units are mainly used to provide thermal management for the entire battery system. They are divided into low-pressure and high-pressure sections. The high-pressure section is used to drive the compressor (some water-cooled units have a PTC heating function, and the high-pressure section can provide high-voltage electricity to the PTC). The low-pressure section mainly consists of a condenser fan and a water pump. The condenser fan dissipates heat from the heat exchanger, while the water pump delivers the low-temperature coolant to the battery box flow channel, removing the heat from the bottom of the battery cell through heat exchange.

[0113] The main function of an on-board DC / DC converter is to convert the high-voltage electricity of the battery system into the low-voltage electricity required by the vehicle, thereby enabling the low-voltage components on the vehicle to operate. At the same time, it also acts as a charger for the lead-acid battery, ensuring that the lead-acid battery is fully charged. Once the high-voltage power to the vehicle is cut off, the lead-acid battery will provide low-voltage electricity to the vehicle.

[0114] Onboard chargers are typically connected to the system's charging circuit. However, some vehicles omit this device and connect directly to a fast-charging socket, charging the vehicle through an external charging station.

[0115] The motor controller is used to drive the motor and is an important load at the output end of the entire battery system.

[0116] This application adds an auxiliary fire-fighting unit to the battery system to enhance the fire safety capability of the entire battery system. The unit integrates fire extinguishing media, which can be delivered to the battery box by a pump in the unit, thereby achieving the fire extinguishing function.

[0117] The fire protection unit is connected to the lead-acid battery load terminal, and it also has an internal storage battery that can serve as a backup power source to power its internal control unit and pump.

[0118] Since the high-voltage power is usually disconnected after the battery system experiences thermal runaway, in order to ensure that the water-cooled unit can still operate in the vehicle after the power is cut off, the system architecture in this application includes two units: a control box and an auxiliary converter (auxiliary DC / DC).

[0119] Figure 6 This is a schematic diagram of the internal structure of the control box. Please refer to it. Figure 6 The control box input terminal is designed with 8 branches, which correspond to each battery box in the two battery branches of the battery system. In this embodiment, there are 8 battery boxes. Each branch has a diode and a relay unit in the positive terminal and a fuse in series in the negative terminal. The diode is to prevent the formation of circulating current when multiple branches are connected in parallel. The relay can control the discharge of the branch. One end of the control coil of these relays is grounded, and the other end of the control electrode is connected to the high-level pin in the auxiliary control unit. The auxiliary control unit can arbitrarily switch the relays on and off according to external conditions.

[0120] The auxiliary control unit in the control box is powered by an external lead-acid battery. The auxiliary control unit can also communicate with the BMS via CAN communication. CAN (Controller Area Network) is a serial communication protocol commonly used in automotive and industrial control systems, allowing data exchange between multiple devices or control units.

[0121] The auxiliary DC / DC unit is used to boost the voltage output from the control box, raising the voltage of a single battery box to the rated voltage required by the water-cooled unit, thereby ensuring the normal operation of the water-cooled unit.

[0122] Figure 7 This is a schematic diagram showing the connection of the main internal components of the high-voltage box in this embodiment. Please refer to... Figure 7 The two battery branches each have a first branch relay and a second branch relay. The first branch relay is connected in series in the first input branch, and the second branch relay is connected in series in the second input branch. The first and second branch relays are connected in parallel. The pre-charge relay, charging relay, and main positive relay are connected in series in the main circuit, and are also connected in parallel. In this embodiment, the water-cooled unit relay is moved to the rear end of the main positive relay. To ensure the water-cooling circuit is energized during charging, the water-cooled unit relay is connected across the main positive relay and the charging relay (these two relays are mutually exclusive and cannot be closed simultaneously). As long as one relay is closed, the water-cooled unit can receive high voltage. This also prevents the water-cooled relays from sticking together, which could cause the water-cooled unit to continuously carry high voltage and pose a safety hazard.

[0123] Figure 8 This is a flowchart of a control method for a battery management system provided in this embodiment. Please refer to it. Figure 8 This embodiment provides a control method for a battery management system, the control method including:

[0124] Step 101: Confirm that a thermal runaway event has occurred.

[0125] Figure 9 This is a flowchart of the control method for the pool management system provided in this embodiment. Please refer to it. Figure 9 In this embodiment, determining that a thermal runaway event has occurred when the battery is in operation includes:

[0126] Step 201: Monitor the temperature of each battery box in each battery branch in real time.

[0127] The BMS monitors the temperature of each battery compartment in each battery branch in real time. This is to detect abnormal temperature changes in the battery compartments in a timely manner, as these changes may be early signs of thermal runaway events.

[0128] Step 202: Determine if there are any abnormalities in the temperature values ​​of each battery box.

[0129] If an abnormal temperature value is detected in a battery compartment during monitoring, the BMS will further check whether the smoke detection value of that battery compartment is abnormal, and proceed to step 203.

[0130] In this embodiment, the abnormality of the temperature value of each battery box can be determined by confirming whether the temperature of the battery box is greater than the temperature safety threshold. When the temperature of a certain battery box is greater than the temperature safety threshold, the temperature of that battery box is judged to be abnormal.

[0131] Step 203: Check if the smoke detection values ​​of each battery compartment are abnormal.

[0132] The smoke detection value can be the concentration value of smoke, or for example, the concentration value of gases such as carbon monoxide.

[0133] An abnormal smoke detection reading may indicate a chemical reaction inside the battery pack, producing smoke or harmful gases. If an abnormal smoke detection reading is detected, the BMS will determine that a thermal runaway event has occurred. This is because an abnormal smoke detection reading is often a key indicator of thermal runaway, suggesting that a chain reaction may have begun inside the battery pack, causing a rapid increase in battery temperature and the generation of smoke. If no abnormal smoke detection reading is detected, the BMS will report the fault event information to the vehicle controller.

[0134] If so, then a thermal runaway event has occurred.

[0135] If not, the fault event information is reported to the vehicle controller, which then reduces power upon receiving the information. Since other non-thermal runaway causes may also lead to temperature anomalies, further analysis and processing by the vehicle controller are required. Upon receiving the fault event information, the vehicle controller will take measures to reduce power. This is to prevent further deterioration of the fault and protect the battery system and vehicle safety. This design, through real-time monitoring of temperature and smoke detection values, combined with the vehicle controller's response, forms an effective thermal runaway event detection and response mechanism to ensure the safety of the battery system and vehicle.

[0136] Step 102: Locate the target branch and disconnect the relay of the target branch. The target branch is the battery branch where the battery box that experienced thermal runaway is located.

[0137] In this embodiment, after a thermal runaway event is confirmed, the process proceeds to step 204. The BMS will detect whether the fire suppression unit is activated. If the fire suppression unit is activated, it will control the fire suppression unit to locate the target branch where the battery box with abnormal temperature is located (i.e., the battery branch where the thermal runaway occurred). Simultaneously, it will disconnect the relay of the target branch to isolate the faulty part. This step is to prevent the thermal runaway from spreading to other battery boxes and protect the entire battery system.

[0138] Please continue to refer to this. Figure 9 If the fire suppression unit fails to activate, a fault command is sent to it. Upon receiving the fault command, the fire suppression unit will activate and simultaneously request a shutdown. When the BMS detects a need to activate the fire suppression unit, it uses the fire system equipment control bus communication protocol to send a fault command to the fire suppression unit via CAN or RS485 interface, prompting the unit to activate and execute the shutdown request. If the fire suppression unit fails to activate, the BMS (as part of the main control unit) can send a fault command to it to activate it and simultaneously request a shutdown to ensure safety.

[0139] It is understood that in this embodiment, the determined target branch can be one of the battery branches or all of the battery branches. For example, if there are battery boxes with thermal runaway in both battery branches, then the first branch relay and the second branch relay corresponding to the two battery branches will be disconnected.

[0140] Step 103: Determine whether the first output voltage is greater than the first threshold voltage Un. If yes, enter the forced cooling mode (the water-cooled unit cools the target branch at the first preset power); if no, enter the auxiliary control mode.

[0141] In this embodiment, the first output voltage is the output voltage of the discharge branch, which can be understood as the output voltage of the battery branch that has not experienced thermal runaway. For example, when the first battery branch experiences thermal runaway, it is disconnected, so only the second battery branch discharges. Therefore, it is necessary to determine whether the voltage of the second battery branch is greater than the first threshold voltage Un. If both the first and second battery branches experience thermal runaway, both are disconnected. Therefore, it is necessary to determine whether the output voltage at this time is greater than the first threshold voltage Un. Since there is still some induced current after the battery system is powered off, the value of the first threshold voltage Un here must be at least greater than 0. The first threshold voltage Un is a designed voltage threshold that can meet the discharge requirements of the high-voltage circuit, and can be set according to the battery design and application.

[0142] In this embodiment, both the forced cooling mode and the auxiliary control mode are used to control the water-cooled unit to cool the target branch.

[0143] With the above scheme, since the water-cooled unit can receive and execute control commands from the battery management system (BMS) regardless of whether the main positive relay or the charging relay is closed, the BMS will detect whether the output voltage of the battery branch (discharge branch) that has not experienced thermal runaway is greater than the first threshold voltage Un. The first threshold voltage is the voltage that can support direct entry into the forced cooling mode. If the output voltage of the discharge branch does not meet the first threshold voltage Un, an auxiliary control mode is required to cool down the battery to control and mitigate the effects of thermal runaway. Here, even if there are battery boxes that have experienced thermal runaway on each branch, that is, each battery branch... All relays are disconnected, meaning the high-voltage circuit is completely cut off. At this time, the output voltage of the discharge branch is definitely less than the first threshold voltage. Auxiliary control mode can also be used for cooling. Therefore, the control method of the battery management system in this application can cool down the thermally runaway battery box in time, regardless of the situation, as long as thermal runaway occurs. Even if the high-voltage circuit is cut off (i.e., the first threshold voltage is not met after the cut-off), the water cooling system of the entire battery system will not lose power supply. The target branch can be cooled down through auxiliary control mode, thereby cooling down the thermally runaway battery box in time and improving product safety performance.

[0144] Figure 10 This is a schematic diagram illustrating the process of entering forced cooling mode (the water-cooled unit cools the target branch at a first preset power) as provided in this embodiment. Please refer to... Figure 10 Enter forced cooling mode, including:

[0145] Step 301: The BMS sends a thermal runaway information message for the target branch to the water-cooled unit.

[0146] When the BMS determines that a thermal runaway event has occurred in a certain battery branch, it sends a message containing information about the thermal runaway of the target branch to the water chiller. This message is a critical instruction that triggers the water chiller to enter a specific operating mode.

[0147] Step 302: After receiving the thermal runaway information message, the water-cooled unit is used to cool the target branch at a first preset power to cool the target branch. Cooling the target branch includes cooling the battery box in the target branch where thermal runaway has occurred.

[0148] Upon receiving a thermal runaway information message from the BMS, the water-cooled unit immediately begins cooling at the first preset power. This mode is designed to rapidly cool the battery compartment experiencing thermal runaway, controlling and mitigating its further progression. In high-power cooling mode, the water-cooled unit cools the target branch, focusing particularly on the battery compartment experiencing thermal runaway. This step is to prevent the thermal runaway from affecting surrounding battery compartments, protecting the overall safety of the battery system.

[0149] Step 303: After the water-cooled unit cools at the first preset power, determine whether the temperature Tmax of the battery box that has experienced thermal runaway is lower than the first threshold temperature T1. If so, control the water-cooled unit to be in standby mode; if not, monitor the voltage value on the discharge branch in real time.

[0150] In this embodiment, determining whether the temperature Tmax of the battery box that has experienced thermal runaway is lower than the first threshold temperature T1 includes step 312: real-time monitoring of the temperature of the battery box that has experienced thermal runaway, that is, real-time monitoring of the temperature of the battery box with abnormal temperature.

[0151] After the water-cooled unit cools at a first preset power, the BMS continuously monitors the temperature Tmax of the battery compartment where thermal runaway has occurred to determine if it is below a preset first threshold temperature T1. If the battery compartment temperature is below the first threshold temperature, the BMS controls the water-cooled unit to enter standby mode to maintain the battery compartment temperature within a safe range and reduce energy consumption. If the battery compartment temperature is not below the first threshold temperature T1, the BMS continues to monitor the voltage value on the discharge branch in real time to ensure that the battery system operates within a safe voltage range and is prepared to adjust the operating mode of the water-cooled unit at any time. The advantages of this control method are: the BMS can quickly identify thermal runaway events and notify the water-cooled unit to achieve rapid cooling; by monitoring the battery compartment temperature and adjusting the operating mode of the water-cooled unit according to the actual situation, the battery compartment temperature can be effectively controlled to prevent overheating; and by switching to a low-power cooling mode while ensuring safety, energy consumption can be reduced and the system's energy efficiency improved. This design provides an effective thermal management strategy to ensure that the battery system can respond and handle thermal runaway events quickly and effectively, thereby improving the safety and reliability of the battery system.

[0152] In one embodiment, real-time monitoring of the voltage value on the discharge branch further includes step 313: determining whether the voltage value U on the discharge branch is greater than the second threshold voltage Ux; if not, controlling the water-cooled unit to shut down and entering the auxiliary control mode; if so, determining again every 50ms.

[0153] The second threshold voltage Ux can be understood as the protection cut-off voltage of the discharge branch. This is to prevent the battery from over-discharging. When the BMS detects that the battery voltage drops to the second threshold voltage Ux, it will trigger the protection mechanism to prevent the battery from over-discharging and thus protect the battery from damage.

[0154] The BMS monitors the voltage on the discharge branch in real time to ensure the battery system operates within a safe voltage range, preventing over-discharge of the battery and enabling timely response to voltage anomalies. If the voltage falls below the second threshold voltage, it is considered insufficient. In this case, the water-cooled unit relay is disconnected, followed by the main negative and main positive relays. After completing these actions, the system enters auxiliary control mode, shutting down the water-cooled unit. This saves energy, especially in cases of insufficient voltage, helping to extend battery life and prevent battery damage caused by low voltage.

[0155] Figure 11 For a flowchart of the intermediate steps from shutting down the water-cooled unit to entering auxiliary control mode, please refer to [link / reference needed]. Figure 11 The process includes: step 314, reporting a voltage deficiency signal to the VCU and requesting a voltage reduction, the VCU being used to reduce the voltage after receiving the voltage deficiency signal.

[0156] Step 315, after a 500ms interval, disconnect the water-cooled unit relay.

[0157] Step 316, after a 500ms interval, disconnect the main negative relay.

[0158] Step 317, after a 500ms interval, disconnect the main positive relay.

[0159] After completing the above controls, the BMS enters the auxiliary control mode.

[0160] Understandably, after applying high voltage, the BMS enters auxiliary control mode to continue cooling the thermally runaway branch. This ensures that the thermally runaway battery box can be cooled in a timely manner under any circumstances. Even if the high-voltage circuit is disconnected (i.e., the second threshold voltage Ux is not met after the disconnection), the water cooling system of the entire battery system will not lose power supply. The auxiliary control mode can be used to cool the target branch, thereby cooling the thermally runaway battery box in a timely manner and improving product safety performance.

[0161] Figure 12 For the flowchart of entering the auxiliary control mode provided in this embodiment, please refer to [link / reference]. Figure 12 In this embodiment, entering the auxiliary control mode includes:

[0162] Step 401: Send a start message to the auxiliary control unit.

[0163] When the BMS determines that it needs to enter the auxiliary control mode, the BMS will send a start message to the auxiliary control unit to enable subsequent operations in the auxiliary control mode.

[0164] The auxiliary control unit is located inside the control box and can control each battery box in the battery system. The auxiliary control unit can switch the relays on and off arbitrarily according to external conditions.

[0165] Step 402: After receiving the start message, the auxiliary control unit determines whether the voltage of each battery box is less than the cutoff voltage. If so, it enters the low-pressure cooling mode (the water-cooled unit cools at the second preset power). If not, it controls the auxiliary unit to determine the working battery box, which is the battery box with the highest voltage among all battery boxes.

[0166] It is understood that the cutoff voltage in this embodiment is a safe voltage value for each battery box set based on experience. The cutoff voltage can be greater than or equal to the cutoff voltage of the battery box's over-discharge protection.

[0167] In some embodiments, the working battery box can be determined by determining the battery box's charge level, i.e., the battery box with the highest charge level among all battery boxes.

[0168] Upon receiving the start-up message, the auxiliary control unit checks whether the voltage of each battery box in the target branch is lower than the cutoff voltage. If the voltage of all battery boxes is lower than the cutoff voltage, the auxiliary control unit enters a low-pressure cooling mode, meaning the water-cooled unit operates at a second preset power to compensate for insufficient voltage. This second preset power is used to power the water-cooled unit's condenser fan and water pump. If not all battery boxes are lower than the cutoff voltage, the auxiliary control unit identifies the battery box with the highest voltage in the target branch as the working battery box.

[0169] Step 403: After the auxiliary control unit determines the working battery box, it closes the relay of the working battery box to start the auxiliary converter. The auxiliary converter is used to boost the voltage after startup so that the water-cooled unit can cool the target branch at a first preset power.

[0170] Once the working battery box is identified, the auxiliary control unit closes the relay for that battery box to start the auxiliary converter. After startup, the auxiliary converter boosts the voltage to ensure the water-cooled unit can cool the target branch at the first preset power. The water-cooled unit then cools the target branch in high-power cooling mode, particularly the battery box experiencing thermal runaway.

[0171] Step 404: After the water-cooled unit cools at the first preset power, determine whether the temperature Tmax of the battery box that has experienced thermal runaway is lower than the first threshold temperature T1. If yes, control the water-cooled unit to be in standby mode; if no, control the auxiliary control unit to monitor the voltage value of the battery box that has experienced thermal runaway in real time.

[0172] After the water-cooled unit cools at the first preset power, the BMS monitors the temperature Tmax of the battery compartment where thermal runaway has occurred to determine if it is below a first threshold temperature T1. If the temperature is below the first threshold temperature T1, the BMS controls the water-cooled unit to enter standby mode to maintain the battery compartment temperature within a safe range and reduce energy consumption. If the temperature Tmax of the thermally runaway battery compartment is not below the first threshold temperature T1, the BMS controls the auxiliary control unit to monitor the voltage value of the thermally runaway battery compartment in real time to ensure that the battery system operates within a safe voltage range and is ready to adjust the operating mode of the water-cooled unit at any time. This design provides an effective thermal management strategy, flexibly selecting the cooling mode according to the battery compartment voltage, ensuring battery safety while maximizing the use of available energy. By using voltage boost and converters, the cooling efficiency of the water-cooled unit is improved, enabling a rapid response to thermal runaway events. This enhances the safety and reliability of the battery system.

[0173] In one embodiment, the control auxiliary control unit monitors the voltage value of the thermally runaway battery pack in real time, including step 405: determining whether the voltage value Uworking of the working battery pack is lower than the third threshold voltage U3, and if so, disconnecting the relay of the working battery pack.

[0174] Understandably, the third threshold voltage U3 is the over-discharge protection cutoff voltage of the working battery box. Disconnecting the working battery box relay includes controlling the auxiliary control unit to report to the BMS that the working battery box voltage is insufficient and requesting a high-voltage reduction. After receiving the information from the auxiliary control unit reporting that the working battery box voltage is insufficient and requesting a high-voltage reduction, the BMS controls the disconnection of the working battery box relay and reduces the high voltage.

[0175] Through the above scheme, the auxiliary control unit continuously monitors the voltage value of the working battery box (i.e., the battery box with the highest voltage in the target branch). This is to ensure that the battery box operates within a safe voltage range and prevent damage caused by excessively low voltage. The auxiliary control unit determines whether the voltage value of the working battery box is lower than a preset third threshold voltage U3. The third threshold voltage U3 is a voltage limit set to ensure battery safety. If the voltage value of the working battery box is lower than the third threshold voltage U3, the auxiliary control unit controls the disconnection of the relay for that working battery box. This measure aims to prevent damage to the battery box due to excessively low voltage, while also protecting the entire battery system from potential damage. By disconnecting the relay, the connection between the battery box and the system can be severed, thereby avoiding battery damage or other safety issues caused by excessively low voltage. By monitoring the voltage of the working battery box in real time and performing corresponding control according to preset thresholds, the BMS can effectively manage the battery pack, ensuring the performance, safety, and driving range of the electric vehicle.

[0176] Figure 13For the flowchart of entering the low-pressure cooling mode (the water-cooled unit cools at the second preset power) provided in this embodiment, please refer to... Figure 13 In this embodiment, entering the low-pressure cooling mode includes:

[0177] The startup and control process of low-pressure cooling mode involves the coordinated operation of the battery management system (BMS), vehicle control unit (VCU), and water-cooled unit.

[0178] Step 501: Send a closing message to the vehicle controller.

[0179] When the BMS determines that it needs to enter low-pressure cooling mode, it sends a closed message to the vehicle controller, which is a signal instructing the vehicle controller to perform a specific operation.

[0180] Step 502: The vehicle controller is used to close the low-pressure circuit of the water-cooled unit after receiving the closing message.

[0181] In this embodiment, the high-pressure circuit must be disconnected before closing the low-pressure circuit of the water-cooled unit.

[0182] Upon receiving the closing message, the vehicle controller closes the low-voltage circuit of the water-cooled unit. This step is to prepare the water-cooled unit to operate in low-power mode to adapt to the current voltage conditions of the battery system.

[0183] Step 503: After the low-pressure circuit of the water-cooled unit is closed, control the water-cooled unit to start the condenser fan and water pump.

[0184] After the low-pressure circuit of the water-cooled unit is closed, the vehicle controller will control the water-cooled unit to start the condenser fan and water pump. These two components are the core of the water-cooling system, responsible for heat dissipation and circulating coolant to reduce the temperature of the battery pack.

[0185] Step 504: After the water-cooled unit starts the condenser fan and water pump, determine whether the temperature of the battery box where thermal runaway has occurred is lower than the first threshold temperature. If so, control the water-cooled unit to cool at the second preset power.

[0186] Determining whether the temperature of the battery compartment experiencing thermal runaway is below a first threshold temperature includes the following steps: real-time monitoring of the temperature of the battery compartment experiencing thermal runaway.

[0187] After the water-cooled unit starts its condenser fan and water pump, the BMS continuously monitors the temperature of the battery compartment where thermal runaway has occurred to determine if it has fallen below a first threshold temperature. If the battery compartment temperature is below the first threshold temperature, the BMS controls the water-cooled unit to cool at a second preset power level. This mode aims to maintain the battery compartment temperature within a safe range while reducing energy consumption. This design allows for flexible switching of cooling modes based on the actual voltage and temperature conditions of the battery compartment to adapt to different operating states. Under low voltage conditions, by using a low-pressure cooling mode, the system can optimize energy use while ensuring safety. By monitoring the battery compartment temperature in real time and adjusting the water-cooled unit's operating mode according to temperature changes, the system can better protect the battery and prevent further deterioration of the thermal runaway event.

[0188] It is understood that in the low-power cooling mode of this embodiment, that is, the water-cooled unit is in standby mode, once the BMS detects an abnormal upward trend in the battery box temperature, the previous stage cooling mode will be immediately activated.

[0189] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A battery box system, characterized in that, Includes multiple battery boxes, a thermal management system, and an auxiliary control unit; The thermal management system is used to cool down the battery box that has experienced thermal runaway. The auxiliary control unit is connected to each of the battery boxes and is used to control any of the battery boxes to provide voltage to the thermal management system.

2. The battery box system according to claim 1, characterized in that, The auxiliary control unit includes a control box and an auxiliary converter, and the control box is connected to each of the battery boxes respectively; The input terminal of the auxiliary converter is connected to the control box, and the output terminal of the auxiliary converter is connected to the thermal management system. The auxiliary converter is used to boost the voltage output by the control box so that the voltage output by the control box reaches a first voltage threshold.

3. The battery box system according to claim 2, characterized in that, The input terminal of the control box is provided with multiple control branches, and the multiple control branches are respectively connected to the multiple battery boxes; Each of the control branches has a positive terminal and a negative terminal; a diode and a battery box relay corresponding to the battery box are connected in series in the positive terminal, and the battery box relay is used to control the on / off state of the corresponding control branch; a fuse is connected in series in the negative terminal.

4. The battery box system according to any one of claims 1 to 3, characterized in that, It also includes an external power supply unit, which is connected to the auxiliary control unit and is used to supply power to the auxiliary control unit.

5. The battery box system according to any one of claims 1 to 3, characterized in that, The multiple battery boxes are divided into at least two battery branches. When each group of battery branches has at least two battery boxes, the battery boxes in each group of battery branches are connected in series.

6. The battery box system according to claim 5, characterized in that, It also includes a high-voltage box unit, with each of the battery branches connected to the input terminal of the high-voltage box unit, and the output terminal of the high-voltage box unit connected to the thermal management system.

7. The battery box system according to claim 6, characterized in that, The thermal management system includes a water-cooled unit with a cooling function, and the output of the high-pressure box unit is connected to the water-cooled unit.

8. The battery box system according to claim 7, characterized in that, Each of the battery branches is connected in parallel to the input terminal of the high-voltage box unit; Each of the battery branches is also connected to a charging device, and the charging device is connected in parallel to the output terminal of the high-voltage box unit; The water-cooled unit is connected between the output end of the high-voltage box unit and the charging equipment.

9. The battery box system according to claim 8, characterized in that, The high-voltage box unit includes a first input terminal, a first output terminal, a charging terminal, a branch relay, a main positive relay, a water-cooling relay, and a charging relay corresponding to multiple battery branches. The first input terminal is connected to the first terminal of each of the multiple branch relays, and the multiple branch relays are connected in parallel with each other; The second terminal of the plurality of branch relays is connected to the first terminal of the main positive relay and the first terminal of the charging relay; The second terminal of the main positive relay is connected to the first terminal of the first output terminal, the first terminal of the water-cooled relay, and the first terminal of the charging terminal, respectively. The second terminal of the charging relay is connected to the first terminal of the first output terminal, the first terminal of the water-cooled unit relay, and the first terminal of the charging terminal, respectively. The second terminal of the water-cooled relay is electrically connected to the water-cooled unit and is used to control the on / off state of the water-cooled unit.

10. An electrical appliance, characterized in that, Includes the battery box system according to any one of claims 1 to 9.

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