Control method and device of battery management system, electronic equipment and vehicle

Abstract

The invention provides a control method and device of a battery management system, electronic equipment and a vehicle, and relates to the technical field of battery management.The control method comprises the steps that a target battery box with thermal runaway in a battery system is positioned, the battery system comprises a target branch and a discharging branch, and the target branch comprises the target battery box; the discharge branch is a battery branch without thermal runaway; disconnecting the connection between the target branch and the thermal management system; and controlling other battery boxes which do not send thermal runaway to provide voltage for the thermal management system, so that the thermal management system cools the battery box corresponding to the target branch. Other battery boxes which do not send thermal runaway are controlled to provide voltage for the thermal management system, so that the thermal management system cools the battery box corresponding to the target branch, a thermal runaway event can be handled in time, the thermal management efficiency can be improved, and the product safety performance can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery management technology, and in particular to a control method, device, electronic equipment and vehicle for a battery management system. Background Art

[0002] With the development of the new energy industry, more and more vehicles are beginning to use lithium batteries as a power source, especially the recent rapid development of the electric heavy-duty truck industry. In order to quickly adapt to more heavy-duty truck models, the current battery system in the heavy-duty truck industry is generally composed of several standard battery boxes connected in series and parallel to form a branch or multiple branches. Since the transportation industry requires vehicles to meet a certain endurance time, in order to meet customer needs, battery companies continue to increase the system power. Some even switch conventional lithium iron phosphate cells to ternary cells with higher energy density in order to arrange more power in a limited space. Since the battery system generally has a high power, it is prone to thermal runaway. When a battery cell in the battery box has thermal runaway, a large amount of heat will be generated inside it, and this heat will continue to spread to the surrounding batteries. If the heat generated by this battery cell is not discharged in time, it will cause heat spread in the entire battery box, and in severe cases, it will cause a fire in the entire battery system. In the prior art, a water cooling system is used to cool down a battery box that has thermal runaway by circulating water. However, when a fire occurs, the BMS (Battery Management System) will disconnect all high-voltage circuits. Since the high-voltage circuit is disconnected, the water cooling system of the entire battery system will also lose power supply and become unable to work, resulting in the inability to remove heat.

[0003] Therefore, there is an urgent need to provide a control method, device, battery system or vehicle for a battery management system that can promptly cool down a battery box that has thermal runaway, thereby improving product safety performance. Summary of the invention

[0004] The present application provides a control method, device, battery system or vehicle for a battery management system, which solves the current problem that a thermal runaway battery box cannot be cooled in time. It can provide voltage to the thermal management system, thereby enabling timely cooling of the thermal runaway battery box and improving product safety performance.

[0005] In a first aspect, the present application provides a control method for a battery management system, the control method comprising: locating a target battery box in a battery system where thermal runaway occurs, wherein the battery system comprises a target branch and a discharge branch, the target branch comprising a target battery box; the discharge branch is a battery branch where thermal runaway does not occur; disconnecting the target branch from the thermal management system; and controlling other battery boxes that do not cause thermal runaway to provide voltage to the thermal management system so that the thermal management system performs a temperature reduction process on the battery box corresponding to the target branch.

[0006] Through the above scheme, by locating and disconnecting the connection between the target branch where thermal runaway occurs and the thermal management system, it is possible to effectively prevent the battery box with thermal runaway from causing damage to the thermal management system or triggering a wider thermal runaway event. This isolation measure can prevent the heat of thermal runaway from being transferred to the thermal management system or other battery boxes, thereby reducing the safety risk of the entire battery system. Thermal runaway is a dangerous situation that may trigger a chain reaction. By promptly identifying and isolating the target battery box, it is possible to prevent thermal runaway from spreading from one battery box to other battery boxes, and prevent the entire battery system from being out of control, thereby significantly improving the safety of the battery system. After thermal runaway occurs, it is necessary to cool down the battery box where thermal runaway occurs. By controlling other battery boxes that have not sent 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, the thermal runaway event can be handled in a timely manner, the thermal management efficiency can be improved, and the product safety performance can be improved.

[0007] In one possible design, other battery boxes that have not sent thermal runaway are controlled to provide voltage to the thermal management system so that the thermal management system cools down the battery box corresponding to the target branch, including: controlling at least two battery boxes in other battery boxes to be connected in series to obtain a branch to be worked on; when the output voltage of the branch to be worked on is greater than or equal to the first voltage threshold, controlling the branch to be worked on to provide voltage to the thermal management system so that the thermal management system cools down the battery box corresponding to the target branch. The thermal management system cools down the battery box corresponding to the target branch, including: controlling the water cooling unit in the thermal management system to cool down the target branch with a first preset power, wherein cooling down the branch to be worked includes cooling down the battery box in the target branch that has thermal runaway; the first preset power is used to satisfy the compression refrigeration function of the water cooling unit.

[0008] Through the above scheme, 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 branch to be worked, the system can dynamically adjust the branch combination according to actual needs. This flexibility enables the system to quickly reconfigure the branch when some battery boxes fail, ensuring that the thermal management system can work normally without relying on a fixed branch layout. The thermal management system can continue to be powered by a combination of other battery boxes, so that the battery box that has thermal runaway can be cooled, thereby improving the safety of the product. By setting a first voltage threshold, it is only allowed to power the thermal management system when the output voltage of the branch to be worked reaches or exceeds the threshold. This voltage control mechanism ensures that the thermal management system operates at a suitable voltage, avoiding inefficiency or equipment damage caused by insufficient or excessive voltage. The thermal management system cools the target branch with a first preset power, and the first preset power is specifically used to meet the compression refrigeration function of the water cooling unit, so that the target battery box can be better cooled. This targeted cooling method can not only effectively reduce the temperature of the thermal runaway battery box, but also avoid overcooling or insufficient cooling, thereby improving the efficiency and accuracy of thermal management.

[0009] In one possible design, at least two battery boxes among the other battery boxes are controlled to be connected in series to obtain a branch to be worked on, including: when the branch to be worked on does not include all the other battery boxes and the output voltage of the branch to be worked on is less than a first voltage threshold, determining a working battery box, the working battery box being 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 performs temperature reduction processing on the battery box corresponding to the target branch.

[0010] Through the above scheme, when the working branch does not contain all other battery boxes and its output voltage is lower than the first voltage threshold, the working battery box with the highest output voltage is selected to power the thermal management system. This dynamic adjustment mechanism can ensure that the thermal management system can always obtain sufficient voltage to avoid failure of the thermal management function due to insufficient voltage. Even if the output voltage of some battery boxes is low or there is a fault, the system can still maintain the function of the thermal management system by selecting the working battery box with the best performance, thereby significantly improving the fault tolerance of the system. 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.

[0011] In a possible design, it 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, the working battery box being the battery box with the highest output voltage among other battery boxes.

[0012] Through the above scheme, when the working branch is a discharge branch and its output voltage is lower than the first voltage threshold, the working battery box with the highest output voltage is selected to power the thermal management system. By dynamically selecting the working battery box to power the thermal management system, the system can continuously cool the target branch to prevent thermal runaway from further aggravation, thereby improving the safety of the system.

[0013] In one possible design, other battery boxes that have not sent thermal runaway are controlled to provide voltage to the thermal management system so that the thermal management system cools down the battery boxes corresponding to the target branch, and also includes: determining a working battery box from other battery boxes, the working battery box being the battery box with the highest output voltage among other battery boxes; when the voltage of the working battery box is greater than or equal to a first voltage threshold, controlling the working battery box to provide voltage to the thermal management system so that the thermal management system cools down the battery box corresponding to the target branch; wherein the thermal management system cools down the battery box corresponding to the target branch, including: controlling the water cooling unit in the thermal management system to cool down the target branch with a first preset power, wherein cooling the target branch includes cooling down the battery box in the target branch that has thermal runaway; the first preset power is used to satisfy the compression refrigeration function of the water cooling unit.

[0014] Through the above scheme, by selecting the battery box with the highest output voltage as the working battery box from other battery boxes that have not experienced thermal runaway, the system can ensure that the thermal management system obtains stable voltage input. This selection mechanism avoids the risk of the thermal management system not being able 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 the thermal management function by selecting the battery box with the best performance, significantly improving the fault tolerance of the system. Only when the voltage of the working battery box is greater than or equal to the first voltage threshold is it allowed to power the thermal management system. 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 in a timely manner, thermal management efficiency can be improved, and energy waste can be reduced.

[0015] In one possible design, the method also includes: when the output voltage of the working battery box is greater than the cutoff voltage and less than a first voltage threshold, increasing the voltage of the working battery box to greater than the first voltage threshold so that the thermal management system cools the battery box corresponding to the target branch.

[0016] With the above scheme, the cut-off voltage is the minimum operating voltage of the battery. When the battery voltage is lower than this value, continued discharge may cause irreversible damage to the chemical substances inside the battery, such as structural damage to the electrode material, decomposition of the electrolyte, etc. The voltage can only be boosted when the working battery box is higher than its cut-off voltage, thereby ensuring the life of the battery box. By boosting the voltage of the working battery box to a voltage threshold that meets the requirements of the thermal management system, it can be ensured that the thermal management system (such as a water cooling unit) can operate at the first preset power, thereby achieving efficient cooling of the thermal runaway battery box in the target branch. This method of voltage boosting avoids the failure of the thermal management function due to insufficient output voltage of the working battery box, ensuring the stability and reliability of the thermal management system.

[0017] In one possible design, the method also includes: when the voltage value of the working battery box is lower than the cut-off voltage of the working battery box, controlling the working battery box to stop providing voltage to the thermal management system and re-determining the working battery box; wherein the cut-off voltage is the lowest working voltage of the working battery box.

[0018] Through the above scheme, by stopping discharge when the voltage is lower than the cut-off voltage, these damages can be effectively avoided and the battery life can be extended. When the working battery box voltage is lower than the cut-off voltage, continuing to supply power may cause the thermal management system to fail to work properly or even cause equipment failure. By switching the battery box in time, it can be ensured that the thermal management system always obtains stable voltage input to avoid system failure due to insufficient voltage. Re-determine the working battery box in time so that the thermal management system can cool down the battery box that has thermal runaway in time.

[0019] In one possible design, the method also includes: when the output voltage of each battery box is less than the cut-off voltage, controlling the vehicle-mounted battery to provide voltage to the water cooling unit so that the water cooling 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 meet the refrigeration function of the water cooling unit to start the condensing fan and water pump.

[0020] Through the above solution, even in extreme cases (all battery box voltages are lower than the cut-off voltage), the system can still provide a minimum cooling function for the water cooling unit through the on-board battery, thereby effectively reducing the temperature of the thermal runaway battery box and reducing the risk of thermal runaway spreading. By maintaining the basic operation of the water cooling unit, equipment damage caused by high temperature can be prevented, improving the overall safety of the system.

[0021] In one possible design, the method further includes: when the temperature value of the battery box in thermal runaway is less than or equal to a first temperature threshold, controlling the water cooling unit to be in a standby state.

[0022] The water-cooling unit can reduce the wear and aging of mechanical parts in standby mode. By running the refrigeration system only when necessary, the service life of key components such as water pumps and fans can be extended. When the temperature of the battery box drops to a safe level, the water-cooling unit enters standby mode to avoid overcooling. This design ensures that the battery system operates within a safe temperature range while avoiding temperature anomalies caused by refrigeration system failure or misoperation. By reducing unnecessary refrigeration operation time, the system can significantly reduce energy consumption. By controlling the water-cooling unit to enter standby mode when the battery box temperature drops to a safe range, the energy efficiency and intelligence level of the system are significantly improved. At the same time, it extends the life of the equipment, reduces operating costs, and further improves the reliability and safety of the system.

[0023] In a second aspect, the present application provides a control device for a battery management system, comprising: a positioning unit, used to locate a target battery box in a battery system where thermal runaway occurs, wherein the battery system comprises a target branch and a discharge branch, the target branch includes a target battery box; the discharge branch is a battery branch where thermal runaway does not occur; a disconnection unit, used to disconnect the connection between the target branch and the thermal management system; a first control unit, used to control other battery boxes that have not sent thermal runaway to provide voltage to the thermal management system, so that the thermal management system performs temperature reduction processing on the battery box corresponding to the target branch.

[0024] The beneficial effects of the battery management system control device provided in the above-mentioned second aspect and each possible design of the above-mentioned second aspect can be referred to the beneficial effects brought about by the above-mentioned first aspect and each possible implementation method of the first aspect, and will not be repeated here.

[0025] In a third aspect, the present application provides an electronic device comprising: a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the steps of any one of the above-mentioned control methods.

[0026] In a fourth aspect, the present application provides a computer-readable storage medium storing a computer program executable by an electronic device, which enables the electronic device to perform any step of the above-mentioned control method when the computer program runs on the electronic device.

[0027] In a fifth aspect, the present application provides a vehicle, specifically comprising: an electronic device for implementing any of the above-mentioned control methods; a processor, the processor running a program, when the program is running, executing the steps of any of the above-mentioned control methods for data output from the electronic device; a storage medium, for storing the program, when the program is running, executing the steps of any of the above-mentioned control methods for data output from the electronic device.

[0028] The above description is only an overview of the technical solution of the embodiment of the present application. In order to more clearly understand the technical means of the embodiment of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 A schematic diagram of the structure of a battery box system provided in one embodiment of the present application.

[0031] Figure 2 This is a flow chart of a control method for a battery management system provided in one embodiment of the present application.

[0032] Figure 3 This is a flow chart of a control method for a battery management system provided in one embodiment of the present application.

[0033] Figure 4 This is a flow chart of a control method for a battery management system provided in one embodiment of the present application.

[0034] Figure 5 This is an architectural diagram of a battery management system provided in one embodiment of the present application.

[0035] Figure 6 This is a schematic diagram of the internal structure of a control box provided in one embodiment of the present application.

[0036] Figure 7 This is a schematic diagram of the connection of the main design components inside the high-voltage box provided in one embodiment of the present application.

[0037] Figure 8 This is a partial flow chart of a control method for a battery management system provided in another embodiment of the present application.

[0038] Fig. 9 This is a partial flow chart of a control method for a pool management system provided in another embodiment of the present application.

[0039] Fig.10 A schematic diagram of a process for entering a forced cooling mode provided in another embodiment of the present application.

[0040] Fig.11 This is a partial flow chart of controlling shutdown of a water cooling unit to enter an auxiliary control mode provided in another embodiment of the present application.

[0041] Fig.12 This is a flowchart after entering the auxiliary control mode provided in another embodiment of the present application.

[0042] Fig.13 This is a flow chart of entering a low-pressure cooling mode provided in another embodiment of the present application. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of the application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification, claims and drawings of this application are intended to cover non-exclusive inclusions.

[0045] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase "embodiments" in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0046] The term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0047] The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned 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.

[0048] In the description of the present application, unless otherwise specified, "plurality" means more than two (including two), and similarly, "multiple groups" means more than two groups (including two).

[0049] The "connection" or "connection" of a circuit structure may refer to not only physical connection, but also electrical connection or signal connection. For example, it may be directly connected, i.e., physically connected, or indirectly connected through at least one intermediate element, as long as the circuit is connected, or it may be internal connection between two elements; signal connection may refer to signal connection through a circuit or through a media medium, such as radio waves. For those of ordinary skill in the art, the specific meanings of the above terms in this application may be understood according to specific circumstances.

[0050] As can be seen from the background technology, in the control method of BMS in the prior art, when a fire occurs, the BMS will disconnect all high-voltage circuits. Since the high-voltage circuit is disconnected, the water cooling system of the entire battery system will also lose power supply and become unable to work, resulting in the inability to remove heat, which will cause harm to the driver.

[0051] In view of this, the present application provides a control method, device, electronic device and vehicle for a battery management system, wherein the control method includes locating a target battery box in a battery system that has thermal runaway, wherein the battery system includes a target branch and a discharge branch, the target branch includes a target battery box; the discharge branch is a battery branch that has not experienced thermal runaway; disconnecting the target branch from the thermal management system; controlling other battery boxes that have not sent thermal runaway to provide voltage to the thermal management system, so that the thermal management system cools down the battery box corresponding to the target branch. The control method enables not only the target battery box that has experienced thermal runaway to be isolated in time when thermal runaway occurs, but also voltage to be provided to the thermal management system, thereby enabling timely cooling of the battery box in thermal runaway and improving product safety performance.

[0052] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0053] BMS (Battery Management System) is used to control and manage each unit inside the battery box system. Figure 1 For a schematic diagram of the structure of a battery box system provided in this embodiment, please refer to Figure 1 The present 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 the battery box that has 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.

[0054] The thermal management system 702 can cool down the battery box that has thermal runaway to prevent the thermal runaway from spreading to other battery boxes or causing more serious safety issues, such as fire or explosion. The auxiliary control unit 703 can dynamically select the battery box that supplies power to the thermal management system 702 according to the voltage state of the battery box to ensure that the thermal management system 702 always obtains a stable voltage input. This battery box system avoids system failure caused by disconnection of high-voltage connection due to thermal runaway, resulting in no power supply to the thermal management system 702, and achieves effective cooling of the thermal runaway battery box.

[0055] In this embodiment, the auxiliary control unit 703 includes a control box and an auxiliary inverter. The control box is connected to each battery box respectively; the input end of the auxiliary inverter is connected to the control box, and the output end of the auxiliary inverter is connected to the thermal management system 702. The auxiliary inverter 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.

[0056] Through the above embodiment, the auxiliary converter increases the voltage output by the control box to the first voltage threshold, ensuring that the thermal management system 702 always obtains a stable voltage input. Even if the voltage of a battery box is insufficient, the auxiliary converter can still increase the voltage through other battery boxes to ensure that the thermal management system 702 can operate normally. This redundant design further enhances the fault tolerance of the system.

[0057] In this embodiment, the input end of the control box is provided with multiple control branches, and the multiple control branches are respectively connected to the multiple battery boxes; wherein 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.

[0058] Through the above embodiment, each control branch corresponds to a battery box, and the on and off of each branch is independently controlled by the battery box relay. This design enables the system to flexibly select the power supply battery box, optimize voltage management, and facilitate the maintenance or replacement of a single battery box. By dispersing the current through multiple control branches, the current load of a single branch is reduced, and the heat loss and voltage drop caused by excessive current are reduced, 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 obtains a stable voltage input, further optimizing the performance of the system. By integrating diodes, relays and fuses in each control branch, the system realizes the centralization of functions, reduces complex external protection circuits and control logic, and reduces the complexity of the system.

[0059] In this embodiment, an external power supply unit is further included, and the auxiliary control unit 703 is connected to the external power supply unit, and the external power supply unit is used to supply power to the auxiliary control unit 703.

[0060] Through the above embodiment, the external power supply unit provides a stable power supply for the auxiliary control unit 703, enabling it to continuously monitor and control the status of the battery box. This design significantly enhances the stability and reliability of the system, optimizes the overall performance of the system, reduces the complexity and cost of the system, and provides a strong guarantee for the efficient operation and thermal management of the battery system.

[0061] In this embodiment, the plurality of battery boxes are divided into at least two battery branches. When each battery branch has at least two battery boxes, the battery boxes in each battery branch are connected in series.

[0062] Through the above embodiment, the battery box is divided into multiple branches, and the battery boxes in each branch can be managed independently. The branch where the battery box with thermal runaway occurs can be disconnected in time to prevent the fault from spreading to other branches or devices, further improving the safety of the system. Even if the battery box in a branch fails, other branches can continue to supply power. This redundant design significantly improves the fault tolerance of the system and reduces the risk of system failure caused by the failure of a single battery box.

[0063] In this embodiment, a high-voltage box unit is further included, each battery branch is respectively connected to the input end of the high-voltage box unit, and the output end of the high-voltage box unit is connected to the thermal management system 702 .

[0064] Through the above embodiments, the high-voltage box unit, as a key connecting component between the battery branch and the thermal management system 702, can centrally manage the electrical connection and protection functions of the battery branch. The high-voltage box unit supports a variety of power supply methods (such as AC220V or DC24V power supply), and can flexibly adapt to different application scenarios and electrical requirements. This flexibility enables the system to be better integrated into different energy storage or electric vehicle architectures. By introducing the high-voltage box unit as a connecting component between the battery branch and the thermal management system 702, this design significantly improves the centralized management capability, safety and reliability of the system, while optimizing the voltage input and operating efficiency of the thermal management system 702.

[0065] In this embodiment, the thermal management system 702 has a water cooling unit, the water cooling unit has a refrigeration function, and the output end of the high-voltage box unit is connected to the water cooling unit.

[0066] Through the above embodiment, the water cooling unit can have a compression refrigeration function, realize heat transfer, and can 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 cooling 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.

[0067] In this embodiment, each battery branch is connected in parallel to the input end of the high-voltage box unit; each battery branch is also connected to a charging device, and the charging device is connected in parallel to the output end of the high-voltage box unit; the water cooling unit is connected between the output end of the high-voltage box unit and the charging device (see Figure 7 ).

[0068] Through the above embodiment, by connecting multiple battery branches in parallel and connecting them to the input end of the high-voltage box unit, the system can centrally manage the voltage and current output of the battery branch. Each battery branch is independently connected to the high-voltage box unit. When a branch fails, the other branches can still work normally, thereby improving the fault tolerance of the system. In addition, the output ends of the charging device and the high-voltage box unit will not be in a closed state at the same time. Therefore, the water cooling unit is connected across the output end of the high-voltage box unit and the charging device to ensure that the water cooling unit can be powered on even during the charging process. Thereby ensuring the stability and reliability of the thermal management system 702.

[0069] In this embodiment, the high-voltage box unit includes a first input terminal corresponding to a plurality of battery branches, a first output terminal, a charging terminal, branch relays corresponding to a plurality of battery branches, a main positive relay, a water-cooling relay, and a charging relay; the first input terminal is respectively connected to the first terminals of the plurality of branch relays, and the plurality of branch relays are connected in parallel with each other; the second terminals of the plurality of branch relays are 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 respectively 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 respectively 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 and off of the water-cooling unit (refer to Figure 7 ).

[0070] Through the above embodiment, each battery branch is connected to the first input terminal of the high-voltage box unit through an independent branch relay. This design allows the system to independently control each branch. For example, when a branch fails, the branch can be cut off individually without affecting the operation of other branches. The main positive relay centrally manages the outputs of all branch relays and is connected to the first output terminal, the water-cooled relay and the charging terminal. This centralized management method simplifies the circuit design while ensuring the overall operating efficiency of the system. The setting of 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 flexibility of the system. The water cooling unit is bridged between the output terminal of the high-voltage box unit and the charging equipment to ensure that the water cooling unit can be powered on even during the charging process. Thereby ensuring the stability and reliability of the thermal management system 702.

[0071] This embodiment also provides an electrical device, including any of the above-mentioned battery box systems.

[0072] Figure 2 This is a flow chart of the control method of the battery management system provided in this embodiment. Please refer to Figure 2 In this embodiment, a control method for a battery management system is provided, including:

[0073] Step 1, locating a target battery box that has thermal runaway in a battery system, wherein the battery system includes a target branch and a discharge branch, the target branch includes a target battery box, and the discharge branch is a battery branch that has not experienced thermal runaway.

[0074] By locating and disconnecting the target branch experiencing thermal runaway from the thermal management system, the battery box experiencing thermal runaway can be effectively prevented from causing damage to the thermal management system or triggering a more extensive thermal runaway event.

[0075] Step 2, disconnect the target branch from the thermal management system.

[0076] This isolation measure can prevent the heat of thermal runaway from being transferred to the thermal management system or other battery boxes, 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 box, thermal runaway can be prevented from spreading from one battery box to other battery boxes, avoiding the entire battery system from getting out of control, thereby significantly improving the safety of the battery system.

[0077] Step 3, controlling other battery boxes that have not sent thermal runaway to provide voltage to the thermal management system, so that the thermal management system cools down the battery box corresponding to the target branch.

[0078] When thermal runaway occurs, the battery box that has 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.

[0079] Figure 3 This is a flow chart of the control method of the battery management system provided in this embodiment. Please refer to Figure 3 In some embodiments, other battery boxes that have not sent thermal runaway are controlled to provide voltage to the thermal management system so that the thermal management system cools down the battery box corresponding to the target branch, including: controlling at least two battery boxes in other battery boxes to be connected in series to obtain a branch to be worked on; when the output voltage of the branch to be worked on is greater than or equal to the first voltage threshold, controlling the branch to be worked on to provide voltage to the thermal management system so that the thermal management system cools down the battery box corresponding to the target branch. The thermal management system cools down the battery box corresponding to the target branch, including: controlling the water cooling unit in the thermal management system to cool down the target branch with a first preset power, wherein cooling down the branch to be worked includes cooling down the battery box in the target branch that has thermal runaway; the first preset power is used to satisfy the compression refrigeration function of the water cooling unit.

[0080] Through the above embodiment, 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 branch to be worked, the system can dynamically adjust the branch combination according to actual needs. This flexibility enables the system to quickly reconfigure the branch when some battery boxes fail, ensuring that the thermal management system can work normally without relying on a fixed branch layout. The thermal management system can continue to be powered by a combination of other battery boxes, so that the battery box that has thermal runaway can be cooled, thereby improving the safety of the product. By setting a first voltage threshold, it is only allowed to power the thermal management system when the output voltage of the branch to be worked reaches or exceeds the threshold. This voltage control mechanism ensures that the thermal management system operates at a suitable voltage, avoiding inefficiency or equipment damage caused by insufficient or excessive voltage. The thermal management system cools the target branch with a first preset power, and the first preset power is specifically used to meet the compression refrigeration function of the water cooling unit, so that the target battery box can be better cooled. This targeted cooling method can not only effectively reduce the temperature of the thermal runaway battery box, but also avoid overcooling or insufficient cooling, thereby improving the efficiency and accuracy of thermal management.

[0081] In some embodiments, at least two battery boxes among the other battery boxes are controlled to be connected in series to obtain a branch to be worked on, including: when the branch to be worked on does not include all the other battery boxes and the output voltage of the branch to be worked on is less than a first voltage threshold, determining a working battery box, the working battery box being 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 performs cooling processing on the battery box corresponding to the target branch.

[0082] Through the above-mentioned embodiments, when the working branch does not contain all other battery boxes and its output voltage is lower than the first voltage threshold, the working battery box with the highest output voltage is selected to power the thermal management system. This dynamic adjustment mechanism can ensure that the thermal management system can always obtain sufficient voltage to avoid failure of the thermal management function due to insufficient voltage. Even if the output voltage of some battery boxes is low or there is a fault, the system can still maintain the function of the thermal management system by selecting the working battery box with the best performance, thereby significantly improving the fault tolerance of the system. 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.

[0083] In some embodiments, at least two battery boxes in other battery boxes are controlled to be connected in series to obtain a branch to be worked on, including: when the branch to be worked on is a discharge branch, and the output voltage of the discharge branch is less than a first voltage threshold, determining a working battery box, and the working battery box is the battery box with the highest output voltage among other battery boxes.

[0084] Through the above embodiment, when the working branch is a discharge branch and its output voltage is lower than the first voltage threshold, the working battery box with the highest output voltage is selected to power the thermal management system. By dynamically selecting the working battery box to power the thermal management system, the system can continuously cool the target branch to prevent further aggravation of thermal runaway, thereby improving the safety of the system.

[0085] Figure 4 This is a flow chart of the control method of the battery management system provided in this embodiment. Please refer to Figure 4In this embodiment, other battery boxes that have not sent thermal runaway are controlled to provide voltage to the thermal management system so that the thermal management system cools down the battery boxes corresponding to the target branch, and also includes the steps of: determining a working battery box from other battery boxes, the working battery box being the battery box with the highest output voltage among other battery boxes; when the voltage of the working battery box is greater than or equal to a first voltage threshold, controlling the working battery box to provide voltage to the thermal management system so that the thermal management system cools down the battery box corresponding to the target branch; wherein the thermal management system cools down the battery box corresponding to the target branch, including: controlling the water cooling unit in the thermal management system to cool down the target branch with a first preset power, wherein cooling the target branch includes cooling down the battery box in the target branch that has thermal runaway; the first preset power is used to meet the compression refrigeration function of the water cooling unit.

[0086] Through the above embodiments, by selecting the battery box with the highest output voltage as the working battery box from other battery boxes that have not experienced thermal runaway, the system can ensure that the thermal management system obtains a stable voltage input. This selection mechanism avoids the risk of the thermal management system not being able 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 the thermal management function by selecting the battery box with the best performance, significantly improving the fault tolerance of the system. Only when the voltage of the working battery box is greater than or equal to the first voltage threshold is it allowed to power the thermal management system. 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 in a timely manner, thermal management efficiency can be improved, and energy waste can be reduced.

[0087] In some embodiments, the method also includes: when the output voltage of the working battery box is greater than the cutoff voltage and less than the first voltage threshold, the voltage of the working battery box is increased to greater than the first voltage threshold so that the thermal management system cools the battery box corresponding to the target branch.

[0088] With the above scheme, the cut-off voltage is the minimum operating voltage of the battery. When the battery voltage is lower than this value, continued discharge may cause irreversible damage to the chemical substances inside the battery, such as structural damage to the electrode material, decomposition of the electrolyte, etc. The voltage can only be boosted when the working battery box is higher than its cut-off voltage, thereby ensuring the life of the battery box. By boosting the voltage of the working battery box to a voltage threshold that meets the requirements of the thermal management system, it can be ensured that the thermal management system (such as a water cooling unit) can operate at the first preset power, thereby achieving efficient cooling of the thermal runaway battery box in the target branch. This method of voltage boosting avoids the failure of the thermal management function due to insufficient output voltage of the working battery box, ensuring the stability and reliability of the thermal management system.

[0089] In some embodiments, the method also includes: when the voltage value of the working battery box is lower than the cut-off voltage of the working battery box, controlling the working battery box to stop providing voltage to the thermal management system and re-determining the working battery box; wherein the cut-off voltage is the lowest working voltage of the working battery box.

[0090] Through the above scheme, by stopping discharge when the voltage is lower than the cut-off voltage, these damages can be effectively avoided and the battery life can be extended. When the working battery box voltage is lower than the cut-off voltage, continuing to supply power may cause the thermal management system to fail to work properly or even cause equipment failure. By switching the battery box in time, it can be ensured that the thermal management system always obtains stable voltage input to avoid system failure due to insufficient voltage. Re-determine the working battery box in time so that the thermal management system can cool down the battery box that has thermal runaway in time.

[0091] In some embodiments, the method also includes: when the output voltage of each battery box is less than the cut-off voltage, controlling the on-board battery to provide voltage to the water cooling unit so that the water cooling 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 meet the cooling function of the water cooling unit to start the condensing fan and water pump.

[0092] Through the above solution, even in extreme cases (all battery box voltages are lower than the cut-off voltage), the system can still provide a minimum cooling function for the water cooling unit through the on-board battery, thereby effectively reducing the temperature of the thermal runaway battery box and reducing the risk of thermal runaway spreading. By maintaining the basic operation of the water cooling unit, equipment damage caused by high temperature can be prevented, improving the overall safety of the system.

[0093] In some embodiments, the method further includes: when the temperature value of the battery box in thermal runaway is less than or equal to a first temperature threshold, controlling the water cooling unit to be in a standby state.

[0094] The first threshold temperature T1 is the safe temperature of the battery box, that is, when the temperature of the battery box is lower than this value, it can be confirmed that the battery box is in a safe state and thermal runaway will never occur. For example, the first threshold temperature may be 50°C.

[0095] The water-cooling unit can reduce the wear and aging of mechanical parts in standby mode. By running the refrigeration system only when necessary, the service life of key components such as water pumps and fans can be extended. When the temperature of the battery box drops to a safe level, the water-cooling unit enters standby mode to avoid overcooling. This design ensures that the battery system operates within a safe temperature range while avoiding temperature anomalies caused by refrigeration system failure or misoperation. By reducing unnecessary refrigeration operation time, the system can significantly reduce energy consumption. By controlling the water-cooling unit to enter standby mode when the battery box temperature drops to a safe range, the energy efficiency and intelligence level of the system are significantly improved. At the same time, it extends the life of the equipment, reduces operating costs, and further improves the reliability and safety of the system.

[0096] Based on the above embodiments, the present application also provides a control device for a battery management system, the control device comprising:

[0097] A positioning unit is used to locate a target battery box that has thermal runaway in a battery system, wherein the battery system includes a target branch and a discharge branch, the target branch includes a target battery box; the discharge branch is a battery branch that has not experienced thermal runaway.

[0098] The disconnection unit is used to disconnect the connection between the target branch and the thermal management system.

[0099] The first control unit is used to control other battery boxes that have not sent thermal runaway to provide voltage to the thermal management system, so that the thermal management system performs temperature reduction processing on the battery box corresponding to the target branch.

[0100] The first control unit also includes a second control unit, which is used to control at least two battery boxes in other battery boxes to be connected in series to obtain a waiting branch; when the output voltage of the waiting branch is greater than or equal to the first voltage threshold, the waiting branch is controlled to provide voltage to the thermal management system so that the thermal management system cools down the battery box corresponding to the target branch. The thermal management system cools down the battery box corresponding to the target branch, including: controlling the water cooling unit in the thermal management system to cool down the target branch with a first preset power, wherein cooling down the waiting branch includes cooling down the battery box in the target branch that has thermal runaway; the first preset power is used to meet the compression refrigeration function of the water cooling unit.

[0101] 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, and the working battery box is the battery box with the highest output voltage among other battery boxes; control the working battery box to provide voltage to the thermal management system so that the thermal management system cools down the battery box corresponding to the target branch.

[0102] The second control unit is also used to determine a working battery box 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, and the working battery box is the battery box with the highest output voltage among other battery boxes.

[0103] The first control unit also includes a third control unit, which is used to determine a working battery box from other battery boxes, and the working battery box is the battery box with the highest output voltage among other battery boxes; when the voltage of the working battery box is greater than or equal to the first voltage threshold, the working battery box is controlled to provide voltage to the thermal management system, so that the thermal management system cools down the battery box corresponding to the target branch; wherein the thermal management system cools down the battery box corresponding to the target branch, including: controlling the water cooling unit in the thermal management system to cool down the target branch with a first preset power, wherein cooling the target branch includes cooling the battery box in the target branch that has thermal runaway; the first preset power is used to meet the compression refrigeration function of the water cooling unit.

[0104] 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 cut-off voltage and less than the first voltage threshold, so that the thermal management system can cool the battery box corresponding to the target branch, wherein the cut-off voltage is the lowest working voltage of the working battery box.

[0105] The control device also includes a redetermining unit, which is used to control the working battery box to stop providing voltage to the thermal management system and redetermine the working battery box when the voltage value of the working battery box is lower than the cut-off voltage of the working battery box.

[0106] The control device also includes a fourth control unit, which is used to control the vehicle-mounted battery to provide voltage to the water cooling unit when the output voltage of each battery box is less than the cut-off voltage, so that the water cooling 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 meet the refrigeration function of the water cooling unit to start the condensing fan and water pump.

[0107] The control device also includes a standby control unit, which is used to control the water cooling unit to be in a standby state when the temperature value of the battery box in thermal runaway is less than or equal to a first temperature threshold.

[0108] Since the control device of the battery management system is used to implement its control method, the method and its beneficial effects have been described in detail in the previous embodiments, and thus will not be repeated in this application.

[0109] Based on the above embodiments, the present 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; a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the steps of any one of the above control methods.

[0110] The present application also provides a computer-readable storage medium storing a computer program executable by an electronic device. When the computer program runs on the electronic device, the electronic device executes the steps of any one of the above control methods.

[0111] The present application also provides a vehicle, specifically comprising: an electronic device for implementing any of the above-mentioned control methods; a processor, the processor running a program, when the program is running, executing the steps of any of the above-mentioned control methods for data output from the electronic device; a storage medium, for storing the program, when the program is running, executing the steps of any of the above-mentioned control methods for data output from the electronic device.

[0112] Example 1

[0113] Figure 5 This is the battery management system architecture diagram provided in this embodiment. Please refer to Figure 5 The battery management system architecture includes: a battery box part, each battery box integrates multiple battery modules and a battery slave control unit (Battery Management Unit, BMU). In order to increase the capacity of the battery system, multiple battery branches are generally set, for example, Figure 1 There are two battery branches in the system, where every four battery boxes form a battery branch. The two battery branches are connected in parallel, and the four battery boxes in each battery branch are connected in series. The two branches converge into the high-voltage box, and the high voltage output from the high-voltage box enters the water cooling unit, on-board converter (on-board DC / DC), on-board charger, motor controller, etc. (There are usually other high-voltage load components on the vehicle, which are not the focus of this solution description, so they are not listed one by one).

[0114] The water cooling unit is mainly used to provide thermal management for the entire battery system. It is divided into two parts: low-pressure and high-pressure. The high-pressure part is used to drive the compressor (some water cooling units have PTC heating function, and the high-pressure part can provide high-voltage electricity for PTC), while the low-pressure part is mainly composed of a condensing fan and a water pump. The condensing fan dissipates heat for the heat exchanger, while the water pump transports the low-temperature coolant to the flow channel of the battery box, and takes away the heat from the bottom of the battery cell through heat exchange.

[0115] The on-board DC / DC mainly converts the high-voltage electricity of the battery system into the low-voltage electricity required by the vehicle, so as to meet the operation of the low-voltage components on the vehicle. At the same time, it also acts as a charger for the lead-acid battery, thereby ensuring that the lead-acid battery is fully charged. Once the high-voltage power of the vehicle is cut off, the lead-acid battery will provide low-voltage power for the entire vehicle.

[0116] The on-board charger is generally connected to the system charging circuit. Some vehicles do not have this device and are directly connected to the fast charging socket to charge the vehicle through an external charging pile.

[0117] The motor controller is used to drive the motor and is an important load at the output end of the entire battery system.

[0118] In this application, an auxiliary fire-fighting unit is added to the battery system to enhance the fire safety capability of the entire battery system. A fire-extinguishing medium is integrated inside the unit, and the fire-extinguishing medium can be transported to the battery box through a pump in the unit, thereby achieving a fire-extinguishing function.

[0119] The fire fighting unit is connected to the load end of the lead-acid battery, and a storage battery is designed inside it, which can be used as a backup power source to provide power for the control unit and pump inside it.

[0120] Since the high voltage power is generally disconnected after the battery system experiences thermal runaway, in order to ensure that the water cooling unit can still work after the vehicle is powered off, two units, a control box and an auxiliary converter (auxiliary DC / DC), are set in the system architecture of this application.

[0121] Figure 6 This is a schematic diagram of the internal structure of the control box. Please refer to Figure 6 The input end of the control box 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. A diode and a relay unit are designed in the positive electrode of each branch, and a fuse is connected in series in the negative electrode. The diode prevents the formation of a circular current when multiple branches are connected in parallel. The relay can control the discharge of the branch. One end of these relay control coils is connected to a common ground, and the other end of the control pole is connected to the high-level pin in the auxiliary control unit. The auxiliary control unit can switch the relay on and off arbitrarily according to external conditions.

[0122] The auxiliary control unit in the control box is powered by an external lead-acid battery, and the auxiliary control unit can also communicate with the BMS via CAN communication. CAN communication (Controller Area Network) is a serial communication protocol commonly used in automotive and industrial control systems, which allows data exchange between multiple devices or control units.

[0123] The auxiliary DC / DC unit is used to boost the voltage output by the control box and increase the voltage of a single battery box to the rated required voltage of the water-cooling unit, thereby ensuring the normal operation of the water-cooling unit.

[0124] Figure 7 This is a schematic diagram of the connection of the main design components inside the high-voltage box in the embodiment of this application. Please refer to Figure 7 , the two battery branches correspond to the first branch relay and the second branch relay, the first branch relay is connected in series in the first input branch, the second branch relay is connected in series in the second input branch, the first branch relay and the second branch relay are connected in parallel with each other, the pre-charge relay, the charging relay and the main positive relay are connected in series in the main trunk, and the pre-charge relay, the charging relay and the main positive relay are connected in parallel with each other. In the technical solution of this embodiment, the water-cooling unit relay is moved to the rear end of the main positive relay. At the same time, in order to ensure that the water-cooling circuit can be energized during the charging process, we bridge the water-cooling unit relay between the main positive relay and the charging relay (these two relays are in a mutually exclusive relationship and are prohibited from being in a closed state at the same time). As long as one relay is closed, the water-cooling unit can pass high voltage. It can also avoid the adhesion of the water-cooling relay, so that the water-cooling unit always carries high voltage electricity, which creates a certain risk of safety hazards.

[0125] Figure 8 This is a flow chart of a control method of a battery management system provided in this embodiment. Figure 8 In this embodiment, a control method for a battery management system is provided, and the control method includes:

[0126] Step 101, determining whether a thermal runaway event occurs.

[0127] Fig. 9 This is a flow chart of the control method of the pool management system provided in this embodiment. Please refer to Fig. 9 In this embodiment, when the battery is in working state, determining that a thermal runaway event occurs includes:

[0128] Step 201 , real-time monitoring of the temperature of each battery box in each battery branch.

[0129] The BMS monitors the temperature of each battery box in each battery branch in real time to detect abnormal temperature changes in the battery box in a timely manner, which may be early signs of thermal runaway events.

[0130] Step 202: Determine whether there is an abnormality in the temperature value of each battery box.

[0131] If it is found during the monitoring process that the temperature value of a battery box is abnormal, the BMS will further detect whether the smoke sensor value of the battery box is abnormal and enter step 203.

[0132] In this embodiment, the abnormality in the temperature value of each battery box can be determined by confirming whether the battery box temperature is greater than the temperature safety threshold. When the temperature of a battery box is greater than the temperature safety threshold, it is determined that the battery box temperature is abnormal.

[0133] Step 203, detecting whether the smoke sensing value of each battery box is abnormal.

[0134] The smoke sense value may be a smoke concentration value, for example, a concentration value of a gas such as carbon monoxide.

[0135] Abnormal smoke values ​​may indicate that a chemical reaction has occurred inside the battery box, producing smoke or harmful gases. If an abnormal smoke value is detected, the BMS will determine that a thermal runaway event has occurred. This is because abnormal smoke values ​​are usually an important indicator of a thermal runaway event, indicating that a chain reaction may have begun inside the battery box, causing the battery temperature to rise sharply and produce smoke. If the smoke value does not detect an abnormality, the BMS will report the fault event information to the vehicle controller.

[0136] If so, it is determined that a thermal runaway event has occurred.

[0137] If not, the fault event information is reported to the vehicle controller, which is used to reduce power after receiving the fault event information. Temperature anomalies may also be caused by other non-thermal runaway reasons, which require further analysis and processing by the vehicle controller. After receiving the fault event information, the vehicle controller will take measures to reduce power. This is to prevent the fault from further deteriorating and protect the safety of the battery system and vehicle. This design forms an effective thermal runaway event detection and response mechanism by real-time monitoring of temperature and smoke values, combined with the response of the vehicle controller, to ensure the safety of the battery system and vehicle.

[0138] 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 with thermal runaway is located.

[0139] In this embodiment, after determining that a thermal runaway event has occurred, the process proceeds to step 204, where the BMS detects whether the fire protection unit is activated. If the fire protection unit is activated, the fire protection unit is controlled to locate the target branch where the battery box with abnormal temperature is located (i.e., the battery branch where the battery box with thermal runaway occurs is located), and at the same time, the relay of the target branch is disconnected 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.

[0140] Please continue to refer to Fig. 9If the fire unit is not started, a fault command is sent to the fire unit. The fire unit is used to start when receiving the fault command and request to stop at the same time. When the BMS detects that the fire unit needs to be started, it will use the fire system equipment control bus communication protocol to send a fault command to the fire unit through the CAN or RS485 interface to prompt the fire unit to start and execute the stop request. If the fire unit is not started, the BMS (as part of the main control unit) can send a fault command to the fire unit to start it and request to stop at the same time to ensure safety.

[0141] It is understandable that in this embodiment, the target branch to be determined may 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, the first branch relay and the second branch relay corresponding to the two battery branches are disconnected.

[0142] Step 103, determining whether the first output voltage is greater than the first threshold voltage Un, if so, entering the forced cooling mode (the water cooling unit cools down the target branch with the first preset power); if not, entering the auxiliary control mode.

[0143] In this embodiment, the first output voltage is the output voltage of the discharge branch, and the discharge branch can be understood as the output voltage of the battery branch that has not experienced thermal runaway. For example, when the first battery branch has thermal runaway, since it is disconnected, only the second battery branch is discharged. Therefore, at this time, it is determined whether the voltage of the second battery branch is greater than the first threshold voltage Un. If both the first battery branch and the second battery branch have thermal runaway, the first battery branch and the second battery branch are both disconnected. Therefore, at this time, 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 electricity after the battery system is powered off, the value of the first threshold voltage Un here is at least greater than 0. The first threshold voltage Un is a designed voltage threshold that can meet the discharge of the high-voltage circuit, which can be set specifically according to the design and application of the battery.

[0144] In this embodiment, both the forced cooling mode and the auxiliary control mode are used to control the water cooling unit to cool the target branch.

[0145] Through the above scheme, since the water-cooling unit can receive the control instructions of the battery management system and execute the corresponding instructions no matter when the main positive relay is closed or the charging relay is closed, the BMS will detect whether the output voltage of the battery branch (discharge branch) without thermal runaway is greater than the first threshold voltage Un. The first threshold voltage is a 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, it is necessary to adopt an auxiliary control mode for cooling to control and alleviate the impact of thermal runaway. Here, even if there are battery boxes with thermal runaway on each branch, that is, each battery branch All relays are disconnected, that is, the high-voltage circuit is completely disconnected. At this time, the output voltage of the discharge branch must be less than the first threshold voltage. The auxiliary control mode can also be used for cooling. Therefore, the control method of the battery management system in the present application can cool down the thermal runaway battery box in time no matter what the situation is, as long as thermal runaway occurs. Even if the high-voltage circuit is disconnected (that is, the first threshold voltage 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, so that the thermal runaway battery box can be cooled in time, thereby improving the safety performance of the product.

[0146] Fig.10 This is a flow chart of entering the forced cooling mode (the water cooling unit cools down the target branch with the first preset power) provided in this embodiment. Fig.10 , enter forced cooling mode, including:

[0147] Step 301: The BMS sends a thermal runaway information message of a target branch to the water cooling unit.

[0148] When the BMS determines that a battery branch has a thermal runaway event, it will send a message containing the target branch thermal runaway information to the water cooling unit. This message is a key instruction that triggers the water cooling unit to enter a specific working mode.

[0149] Step 302, the water cooling unit is used to cool the target branch at a first preset power after receiving the thermal runaway information message, and cooling the target branch includes cooling the battery box in the target branch where thermal runaway occurs.

[0150] After receiving the thermal runaway information message sent by the BMS, the water cooling unit will immediately cool down at the first preset power. This mode is to quickly cool down the battery box that has thermal runaway to control and alleviate the further development of thermal runaway. In the high-power cooling mode, the water cooling unit cools down the target branch, especially focusing on cooling down the battery box that has thermal runaway. This step is to prevent the impact of thermal runaway on surrounding battery boxes and protect the overall safety of the battery system.

[0151] Step 303, after the water cooling unit is cooled at the first preset power, determine whether the temperature Tmax of the battery box with thermal runaway is lower than the first threshold temperature T1, if so, control the water cooling unit to be in standby mode; if not, monitor the voltage value on the discharge branch in real time.

[0152] In this embodiment, determining whether the temperature Tmax of the battery box with thermal runaway is lower than the first threshold temperature T1 includes step 312: real-time monitoring of the temperature of the battery box with thermal runaway, that is, real-time monitoring of the temperature of the battery box with abnormal temperature.

[0153] After the water cooling unit cools at the first preset power, the BMS will continue to monitor the temperature Tmax of the battery box where thermal runaway occurs to determine whether it is lower than the preset first threshold temperature T1. If the temperature of the battery box is lower than the first threshold temperature, the BMS will control the water cooling unit to be in standby mode to maintain the temperature of the battery box within a safe range while reducing energy consumption. If the temperature of the battery box is not lower than the first threshold temperature T1, the BMS will continue 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 ready to adjust the working mode of the water cooling unit at any time. The advantage of this control method is that the BMS can quickly identify thermal runaway events and notify the water cooling unit to achieve rapid cooling. By monitoring the temperature of the battery box and adjusting the working mode of the water cooling unit according to actual conditions, the temperature of the battery box can be effectively controlled to prevent overheating. Under the premise of ensuring safety, by switching to a low-power cooling mode, energy consumption can be reduced and the energy efficiency of the system can be 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.

[0154] In one embodiment, the voltage value on the discharge branch is monitored in real time, and step 313 is also included: determining whether the voltage value U on the discharge branch is greater than the second threshold voltage Ux, if not, controlling to shut down the water cooling unit and enter the auxiliary control mode; if so, determining again every 50ms.

[0155] The second threshold voltage Ux can be understood as the protection cut-off voltage of the discharge branch, which is to avoid over-discharge of the discharged battery. When the BMS detects that the battery voltage drops to the second threshold voltage Ux, it will trigger the protection mechanism to avoid over-discharge of the battery, thereby protecting the battery from damage.

[0156] BMS monitors the voltage value on the discharge branch in real time to ensure that the battery system operates within a safe voltage range, avoid over-discharge of the discharged battery, and respond to voltage abnormalities in a timely manner. If the voltage is lower than the second threshold voltage, it is considered insufficient voltage. At this time, the water cooling unit relay will be disconnected, and then the main negative and main positive relays will be disconnected respectively. After completing the above actions, the system enters the auxiliary control mode. By controlling the shutdown of the water cooling unit, the system can save energy. Especially in the case of insufficient voltage, this measure helps to extend the service life of the battery and prevent battery damage caused by low voltage.

[0157] Fig.11 For the flow chart of the intermediate steps from shutting down the water cooling unit to entering the auxiliary control mode, please refer to Fig.11 , including: step 314, reporting an undervoltage signal to the VCU and requesting a lower high voltage, the VCU being used to lower the high voltage after receiving the undervoltage signal.

[0158] Step 315, after an interval of 500ms, disconnect the water cooling unit relay.

[0159] Step 316, after an interval of 500ms, disconnect the main negative relay.

[0160] Step 317, after an interval of 500ms, disconnect the main positive relay.

[0161] After completing the above control, the BMS enters the auxiliary control mode.

[0162] It is understandable that after the high voltage is lowered, the BMS enters the auxiliary control mode to continue cooling the branch with thermal runaway, thereby ensuring that the battery box with thermal runaway can be cooled in time under any circumstances. Even if the high-voltage circuit is disconnected (that is, 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, so that the battery box with thermal runaway can be cooled in time, thereby improving product safety performance.

[0163] Fig.12 Please refer to the flowchart after entering the auxiliary control mode provided in this embodiment. Fig.12 In this embodiment, entering the auxiliary control mode includes:

[0164] Step 401: Send a startup message to the auxiliary control unit.

[0165] When the BMS determines that it needs to enter the auxiliary control mode, the BMS will send a startup message to the auxiliary control unit to enable subsequent operations in the auxiliary control mode.

[0166] The auxiliary control unit is located in the control box and can control each battery box in the battery system. The auxiliary control unit can switch the relay open and closed at will according to external conditions.

[0167] Step 402, the auxiliary control unit is used to determine whether the voltage of each battery box is less than the cut-off voltage after receiving the startup message. If so, it enters the low-pressure cooling mode (the water cooling unit cools at the second preset power); if not, the auxiliary unit is controlled to determine the working battery box, which is the battery box with the highest voltage among all the battery boxes.

[0168] It can be understood that the cut-off voltage in this embodiment is a safe voltage value of each battery box set based on experience, and the cut-off voltage may be greater than or equal to the over-discharge protection cut-off voltage of the battery box.

[0169] In some embodiments, the working battery box may be determined by determining the power of the battery box, that is, the battery box with the largest power among the battery boxes.

[0170] After receiving the startup message, the auxiliary control unit will check whether the voltage of each battery box in the target branch is less than the cut-off voltage. If the voltage of all battery boxes is less than the cut-off voltage, the auxiliary control unit will enter the low-voltage cooling mode, that is, the water-cooling unit will cool at the second preset power to adapt to the insufficient voltage. The second preset power is used to meet the cooling function of the water-cooling unit to start the condensing fan and water pump. If the voltage of not all battery boxes is less than the cut-off voltage, the auxiliary control unit will determine the battery box with the highest voltage in the target branch as the working battery box.

[0171] Step 403, after the auxiliary control unit determines the working battery box, the relay of the working battery box is closed to start the auxiliary converter. The auxiliary converter is used to increase the voltage after starting, so that the water cooling unit cools the target branch with the first preset power.

[0172] After determining the working battery box, the auxiliary control unit will close the relay of the battery box to start the auxiliary converter. After starting, the auxiliary converter will increase the voltage to ensure that the water cooling unit can cool the target branch at the first preset power. The water cooling unit cools the target branch in the high-power cooling mode, especially the battery box that has thermal runaway.

[0173] Step 404, after the water cooling unit is cooling at the first preset power, determine whether the temperature Tmax of the battery box with thermal runaway is lower than the first threshold temperature T1, if so, control the water cooling unit to be in standby mode; if not, control the auxiliary control unit to monitor the voltage value of the battery box with thermal runaway in real time.

[0174] After the water-cooling unit cools at the first preset power, the BMS monitors the temperature Tmax of the battery box with thermal runaway to determine whether it is lower than the first threshold temperature T1. If the temperature is lower than the first threshold temperature T1, the BMS controls the water-cooling unit to be in standby mode to maintain the temperature of the battery box within a safe range while reducing energy consumption. If the temperature Tmax of the battery box with thermal runaway is not lower than the first threshold temperature T1, the BMS controls the auxiliary control unit to monitor the voltage value of the thermal runaway battery box in real time to ensure that the battery system operates within a safe voltage range and is ready to adjust the working mode of the water-cooling unit at any time. This design provides an effective thermal management strategy, which flexibly selects the cooling mode according to the voltage of the battery box, which not only ensures the safety of the battery, but also maximizes the use of available energy. Through the use of voltage boost and converter, the cooling efficiency of the water-cooling unit is improved, and the thermal runaway event is quickly responded to. Thereby improving the safety and reliability of the battery system.

[0175] In one embodiment, controlling the auxiliary control unit to monitor the voltage value of the battery box in thermal runaway in real time includes step 405: determining whether the voltage value Uworking of the working battery box is lower than a third threshold voltage U3, and if so, disconnecting the relay of the working battery box.

[0176] It can be understood that the third threshold voltage U3 is the cut-off voltage of the over-discharge protection of the working battery box. Disconnecting the relay of the working battery box includes controlling the auxiliary control unit to report to the BMS that the voltage of the working battery box is insufficient and requesting to lower the high voltage. After receiving the information that the auxiliary control unit reports to the BMS that the voltage of the working battery box is insufficient and requesting to lower the high voltage, the BMS controls to disconnect the relay of the working battery box and lower the high voltage.

[0177] Through the above scheme, the auxiliary control unit will continuously monitor the voltage value of the working battery box (i.e., the battery box with the highest voltage in the target branch) to ensure that the battery box operates within a safe voltage range and prevent damage caused by too low voltage. The auxiliary control unit will determine whether the voltage value of the working battery box is lower than the 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 will control the relay that disconnects the working battery box. This measure is intended to prevent the battery box from being damaged due to too 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 cut off, thereby avoiding battery damage or other safety issues caused by too low voltage. By monitoring the voltage of the working battery box in real time and performing corresponding control according to the preset threshold, the BMS can effectively manage the battery pack and ensure the performance, safety and range of electric vehicles.

[0178] Fig.13For a flow chart of entering the low-pressure cooling mode (the water cooling unit performs cooling at the second preset power) provided in this embodiment, please refer to Fig.13 In this embodiment, entering the low-pressure cooling mode includes:

[0179] The startup and control process of the low-pressure cooling mode involves the coordinated work of the battery management system (BMS), the vehicle controller (VCU) and the water cooling unit.

[0180] Step 501, sending a closing message to the vehicle controller.

[0181] When the BMS determines that it needs to enter low-pressure cooling mode, it sends a closure message to the vehicle controller, which is a signal instructing the vehicle controller to perform a specific action.

[0182] Step 502: the vehicle controller is used to close the low-pressure circuit of the water cooling unit after receiving the closing message.

[0183] In this embodiment, before closing the low-pressure circuit of the water-cooling unit, the high-pressure circuit needs to be disconnected.

[0184] After receiving the closing message, the vehicle controller will close the low-voltage circuit of the water cooling unit. This step is to prepare the water cooling unit to operate in low-power mode to adapt to the current voltage conditions of the battery system.

[0185] Step 503, after the low-pressure circuit of the water-cooling unit is closed, the water-cooling unit is controlled to start the condensing fan and the water pump.

[0186] After the low-pressure circuit of the water-cooling unit is closed, the vehicle controller will control the water-cooling unit to start the condensing fan and water pump. These two components are the core parts of the water cooling system, responsible for heat dissipation and circulating coolant to reduce the temperature of the battery box.

[0187] Step 504, after the water cooling unit starts the condensing fan and the water pump, it is determined whether the temperature of the battery box where thermal runaway occurs is lower than the first threshold temperature. If so, the water cooling unit is controlled to perform cooling at a second preset power.

[0188] Determining whether the temperature of the battery box where thermal runaway occurs is lower than a first threshold temperature includes the steps of: monitoring the temperature of the battery box where thermal runaway occurs in real time.

[0189] After the water-cooling unit starts the condensing fan and water pump, the BMS will continue to monitor the temperature of the battery box that has thermal runaway to determine whether it is lower than the first threshold temperature. If the temperature of the battery box is lower than the first threshold temperature, the BMS will control the water-cooling unit to cool at a second preset power. This mode is designed to maintain the temperature of the battery box within a safe range while reducing energy consumption. This design can flexibly switch the cooling mode according to the actual voltage and temperature conditions of the battery box to adapt to different working conditions. When the voltage is low, by using the low-voltage cooling mode, the system can optimize energy use while ensuring safety. By monitoring the temperature of the battery box in real time and adjusting the working mode of the water-cooling unit according to temperature changes, the system can better protect the battery and prevent further deterioration of thermal runaway events.

[0190] It can be understood that the low-power cooling mode in this embodiment, that is, the mode in which the water cooling unit is in standby state, in the low-power cooling mode, once the BMS detects that the abnormal battery box temperature has an upward trend, the previous stage cooling mode is immediately turned on.

[0191] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A control method for a battery management system, characterized in that: The control method comprises: Locating a target battery box that has thermal runaway in a battery system, wherein the battery system includes a target branch and a discharge branch, the target branch includes the target battery box; the discharge branch is a battery branch that has not thermal runaway; Disconnecting the target branch from the thermal management system; The other battery boxes that have not sent thermal runaway are controlled to provide voltage to the thermal management system so that the thermal management system performs a temperature reduction process on the battery box corresponding to the target branch.

2. The control method according to claim 1, characterized in that: Controlling other battery boxes that have not sent thermal runaway to provide voltage to the thermal management system so that the thermal management system performs a temperature reduction process on the battery box corresponding to the target branch, including: Control at least two battery boxes among the other battery boxes to be connected in series to obtain a branch circuit to be operated; When the output voltage of the waiting working branch is greater than or equal to the first voltage threshold, controlling the waiting working branch to provide voltage to the thermal management system so that the thermal management system performs a temperature reduction process on the battery box corresponding to the target branch; The thermal management system performs a cooling process on the battery box corresponding to the target branch, including: Control the water cooling unit in the thermal management system to cool the target branch with a first preset power, wherein cooling the branch to be worked includes cooling the battery box in the target branch that has thermal runaway; the first preset power is used to meet the compression refrigeration function of the water cooling unit.

3. The control method according to claim 2, characterized in that: The controlling at least two battery boxes in the other battery boxes to be connected in series to obtain a branch circuit to be operated comprises: In the case that the branch to be operated does not include all of the other battery boxes, and the output voltage of the branch to be operated is less than the first voltage threshold, determining a working battery box, the working battery box being the battery box with the highest output voltage among the other battery boxes; The working battery box is controlled to provide voltage to the thermal management system, so that the thermal management system performs a temperature reduction process on the battery box corresponding to the target branch.

4. The control method according to claim 3, characterized in that: The controlling at least two battery boxes in the other battery boxes to be connected in series to obtain a branch circuit to be operated comprises: When the branch to be operated is the discharge branch and the output voltage of the discharge branch is less than the first voltage threshold, a working battery box is determined, and the working battery box is the battery box with the highest output voltage among the other battery boxes.

5. The control method according to claim 1, characterized in that: Controlling other battery boxes that have not sent thermal runaway to provide voltage to the thermal management system so that the thermal management system performs a temperature reduction process on the battery box corresponding to the target branch, further comprising: Determine a working battery box from the other battery boxes, the working battery box being 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, controlling the working battery box to provide voltage to the thermal management system so that the thermal management system performs a temperature reduction process on the battery box corresponding to the target branch; The thermal management system performs a cooling process on the battery box corresponding to the target branch, including: Control the water cooling unit in the thermal management system to cool the target branch with a first preset power, wherein cooling the target branch includes cooling the battery box in the target branch that has thermal runaway; the first preset power is used to satisfy the compression refrigeration function of the water cooling unit.

6. The control method according to any one of claims 3 to 5, characterized in that: The method further comprises: When the output voltage of the working battery box is greater than the cut-off voltage and less than a first voltage threshold, the voltage of the working battery box is increased to be greater than the first voltage threshold so that the thermal management system cools down the battery box corresponding to the target branch, wherein the cut-off voltage is the minimum working voltage of the working battery box.

7. The control method according to claim 6, characterized in that: The method further comprises: When the voltage value of the working battery box is lower than the cut-off voltage of the working battery box, the working battery box is controlled to stop providing voltage to the thermal management system, and the working battery box is re-determined.

8. The control method according to claim 6, characterized in that: The method further comprises: When the output voltage of each battery box is less than the cut-off voltage, the vehicle-mounted battery is controlled to provide voltage to the water cooling unit so that the water cooling 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 meet the cooling function of the water cooling unit to start the condensing fan and the water pump.

9. The control method according to any one of claims 1 to 5, characterized in that: The method further comprises: When the temperature value of the battery box in thermal runaway is less than or equal to a first temperature threshold, the water cooling unit is controlled to be in a standby state.

10. A control device for a battery management system, characterized in that: include: A positioning unit, used for positioning a target battery box in a battery system where thermal runaway occurs, wherein the battery system comprises a target branch and a discharge branch, the target branch comprises the target battery box; the discharge branch is a battery branch where thermal runaway does not occur; A disconnection unit, used to disconnect the connection between the target branch and the thermal management system; The first control unit is used to control other battery boxes that have not sent thermal runaway to provide voltage to the thermal management system, so that the thermal management system performs a temperature reduction process on the battery box corresponding to the target branch.

11. An electronic device, characterized in that: include: A processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the steps of the control method described in any one of claims 1 to 9.

12. A computer-readable storage medium, characterized in that: It stores a computer program executable by an electronic device, and when the computer program runs on the electronic device, the electronic device executes the steps of the control method described in any one of claims 1 to 9.

13. A vehicle, characterized in that: Specifically include: An electronic device, used to implement the control method according to any one of claims 1 to 9; a processor, the processor running a program, and when the program is running, executing the steps of the control method according to any one of claims 1 to 9 for data output from the electronic device; A storage medium for storing a program, wherein when the program is run, the steps of the control method according to any one of claims 1 to 9 are executed for data output from an electronic device.

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