Battery internal short circuit fault diagnosis method, system, computer device and storage medium

Abstract

This application relates to a method for diagnosing internal short-circuit faults in batteries, a computer device, a computer-readable storage medium, and a computer program product. Applied to a battery management system, the system operates on an equivalent circuit model of the target battery. The system includes a data acquisition module and an active balancing circuit. The data acquisition module monitors the individual cell voltages and total currents of multiple cells in the target battery in real time. The method includes: repeatedly switching the operating mode of the target battery and acquiring the individual cell voltages and total currents of multiple cells at the moment of mode switching; correcting the ohmic internal resistance parameter of the target battery in the equivalent circuit model based on the individual cell voltages and total currents; after correcting the ohmic internal resistance parameter, if the active balancing circuit is activated, continuously acquiring the cumulative balancing time of multiple cells; and determining whether a faulty individual cell exists in the target battery based on the cumulative balancing time. This method can diagnose internal short-circuit faults while continuously performing balancing.

Description

Technical Field

[0001] This application relates to the field of battery safety management technology, and in particular to a method, system, computer device, computer-readable storage medium, and computer program product for diagnosing internal short circuit faults in batteries. Background Technology

[0002] Internal short-circuit faults in lithium batteries are a key factor in inducing battery thermal runaway, seriously threatening the safe operation of electric vehicles and energy storage systems.

[0003] Traditional diagnosis of internal short-circuit faults in lithium batteries is usually based on detecting inconsistencies in parameters such as battery voltage and state of charge (SOC). However, in practical applications, because battery management systems are generally equipped with active balancing circuits, they actively eliminate parameter differences between batteries, making it difficult to accurately diagnose internal short-circuit faults in lithium batteries while they are continuously balancing. Summary of the Invention

[0004] Therefore, it is necessary to provide a method, system, computer device, computer-readable storage medium, and computer program product for diagnosing internal short circuit faults in batteries that can accurately diagnose internal short circuit faults during continuous balancing, in order to address the above-mentioned technical problems.

[0005] In a first aspect, this application provides a method for diagnosing short-circuit faults within a battery, applied to a battery management system; the battery management system operates on an equivalent circuit model of the target battery; the battery management system includes a data acquisition module and an active balancing circuit; the data acquisition module is used to monitor the individual cell voltages and total current of multiple cells in the target battery in real time; the method includes:

[0006] The target battery's operating mode is switched multiple times, and the individual cell voltage and total current of multiple cells in the target battery are collected at the moment of the operating mode switch.

[0007] Based on the individual cell voltage and total current, the ohmic internal resistance parameter of the target battery is corrected in the equivalent circuit model.

[0008] After correcting the ohmic internal resistance parameter, if the active balancing circuit is activated, the cumulative balancing time of multiple individual cells in the target battery will be continuously acquired.

[0009] Based on the cumulative equalization time, determine whether there are faulty individual cells in the target battery that have experienced internal short circuit faults.

[0010] In one embodiment, determining whether there is a faulty individual cell with an internal short circuit fault in the target battery based on the cumulative equalization time includes:

[0011] The cumulative equalization time of multiple individual cells is compared with a preset threshold.

[0012] If the cumulative equalization time exceeds a preset threshold, the cell corresponding to the cumulative equalization time will be identified as the faulty cell with an internal short circuit fault.

[0013] In one embodiment, the equivalent circuit model includes an internal short-circuit resistance; the method further includes:

[0014] Select an equalization time window within the cumulative equalization time of the faulty individual cell;

[0015] Based on the active balancing circuit and the energy change of the target battery within the balancing time window, an energy conservation quantification equation is constructed.

[0016] Based on the energy conservation quantization equation, the specific value of the internal short-circuit resistance is calculated.

[0017] In one embodiment, an energy conservation quantification equation is constructed based on the energy changes of the active balancing circuit and the target battery within the balancing time window, including:

[0018] Acquire the equalization energy injected by the active equalization circuit within the equalization time window, as well as the energy change and external functional quantities of the target battery within the equalization time window;

[0019] The relationship between equilibrium energy, the energy change of the target battery, and the energy of external work is analyzed, and a quantitative equation for energy conservation is constructed.

[0020] Secondly, this application also provides a battery management system that operates on an equivalent circuit model of a target battery. The battery management system includes a data acquisition module and an active balancing circuit. The data acquisition module is used to monitor the individual cell voltages and total current of multiple cells in the target battery in real time. The battery management system also includes a fault diagnosis module, which is used for:

[0021] The operating mode of the target battery was switched multiple times, and the individual cell voltage and total current of multiple cells of the target battery were collected at the moment of the operating mode switch.

[0022] Based on the individual cell voltage and total current, the ohmic internal resistance parameter of the target battery is corrected in the equivalent circuit model.

[0023] After correcting the ohmic internal resistance parameter, if the active balancing circuit is activated, the cumulative balancing time of multiple individual cells in the target battery will be continuously acquired.

[0024] Based on the cumulative equalization time, determine whether there are faulty individual cells in the target battery that have experienced internal short circuit faults.

[0025] In one embodiment, the active balancing circuit includes a primary winding, a secondary winding, and a flyback converter; the primary winding is connected to the total positive and negative terminals of the target battery; the secondary winding is connected to multiple individual cells of the target battery; and the flyback converter is used to control the energy injected into the target battery by the active balancing circuit.

[0026] In one embodiment, the data acquisition module includes a voltage acquisition circuit and a current sensor; the data acquisition module is also used to acquire the primary current and primary voltage of the active balancing circuit.

[0027] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0028] The operating mode of the target battery was switched multiple times, and the individual cell voltage and total current of multiple cells of the target battery were collected at the moment of the operating mode switch.

[0029] Based on the individual cell voltage and total current, the ohmic internal resistance parameter of the target battery is corrected in the equivalent circuit model.

[0030] After correcting the ohmic internal resistance parameter, if the active balancing circuit is activated, the cumulative balancing time of multiple individual cells in the target battery will be continuously acquired.

[0031] Based on the cumulative equalization time, determine whether there are faulty individual cells in the target battery that have experienced internal short circuit faults.

[0032] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0033] The operating mode of the target battery was switched multiple times, and the individual cell voltage and total current of multiple cells of the target battery were collected at the moment of the operating mode switch.

[0034] Based on the individual cell voltage and total current, the ohmic internal resistance parameter of the target battery is corrected in the equivalent circuit model.

[0035] After correcting the ohmic internal resistance parameter, if the active balancing circuit is activated, the cumulative balancing time of multiple individual cells in the target battery will be continuously acquired.

[0036] Based on the cumulative equalization time, determine whether there are faulty individual cells in the target battery that have experienced internal short circuit faults.

[0037] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, performs the following steps:

[0038] The operating mode of the target battery was switched multiple times, and the individual cell voltage and total current of multiple cells of the target battery were collected at the moment of the operating mode switch.

[0039] Based on the individual cell voltage and total current, the ohmic internal resistance parameter of the target battery is corrected in the equivalent circuit model.

[0040] After correcting the ohmic internal resistance parameter, if the active balancing circuit is activated, the cumulative balancing time of multiple individual cells in the target battery will be continuously acquired.

[0041] Based on the cumulative equalization time, determine whether there are faulty individual cells in the target battery that have experienced internal short circuit faults.

[0042] The aforementioned battery internal short-circuit fault diagnosis method, system, computer equipment, computer-readable storage medium, and computer program product repeatedly switch the target battery's operating mode and repeatedly collect the individual cell voltages and total currents of multiple individual cells in the target battery at the moment of operating mode switching. Based on the individual cell voltages and total currents, the ohmic internal resistance parameters of the target battery are corrected in the equivalent circuit model. This correction process eliminates the interference of polarization voltage on measurement accuracy and ensures that the equalization strategy is based on the consistency of the battery's true open-circuit voltage (OCV) rather than simply the consistency of the terminal voltage, thereby preventing false equalization. After correcting the ohmic internal resistance parameters, if the active equalization circuit is activated, the cumulative equalization time of multiple individual cells in the target battery is continuously acquired. Based on the cumulative equalization time, it is determined whether there are faulty individual cells in the target battery with internal short-circuit faults. This allows for online identification of internal short-circuit faults while the target battery is continuously equalizing and eliminating inconsistencies. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a diagram illustrating the application environment of a battery internal short-circuit fault diagnosis method in one embodiment.

[0045] Figure 2 This is a flowchart illustrating a battery internal short-circuit fault diagnosis method in one embodiment;

[0046] Figure 3 A circuit diagram of the equivalent circuit model of the target battery in one embodiment;

[0047] Figure 4This is a flowchart illustrating a battery internal short-circuit fault diagnosis method in another embodiment;

[0048] Figure 5 This is a structural block diagram of the battery management system in one embodiment;

[0049] Figure 6 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0051] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0052] The battery internal short-circuit fault diagnosis method provided in this application embodiment can be applied to, for example... Figure 1 In the application environment shown, terminal 102 communicates with server 104 via a network. A data storage system can store the data that server 104 needs to process. The data storage system can be integrated onto server 104 or placed on a cloud or other network server. Specifically, terminal 102 or server 104 connects to a battery management system, which operates on the equivalent circuit model of the target battery. The battery management system includes a data acquisition module and an active balancing circuit. The data acquisition module is used to monitor the individual cell voltage and total current of multiple individual cells in the target battery in real time. Terminal 102 or server 104 executes a battery internal short-circuit fault diagnosis method applied to the battery management system. This method includes: repeatedly switching the operating mode of the target battery and acquiring the individual cell voltage and total current of multiple individual cells of the target battery at the moment of operating mode switching; correcting the ohmic internal resistance parameter of the target battery in the equivalent circuit model based on the individual cell voltage and total current; after correcting the ohmic internal resistance parameter, if the active balancing circuit is activated, continuously acquiring the cumulative balancing time of multiple individual cells in the target battery; and determining whether there is a faulty individual cell in the target battery with an internal short circuit fault based on the cumulative balancing time.

[0053] Terminal 102 can be, but is not limited to, various personal computers, laptops, smartphones, tablets, drones, low-altitude aircraft, IoT devices, and portable wearable devices. IoT devices can include smart speakers, smart TVs, smart air conditioners, smart in-vehicle devices, and projection equipment. Portable wearable devices can include smartwatches, smart bracelets, and head-mounted displays. Head-mounted displays can be virtual reality (VR) devices, augmented reality (AR) devices, and smart glasses. Server 104 can be a standalone physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing cloud computing services.

[0054] In one exemplary embodiment, such as Figure 2 As shown, a method for diagnosing short-circuit faults within a battery is provided, which can be applied to... Figure 1 The method is illustrated using a battery management system connected to terminal 102 as an example. The battery management system operates on the equivalent circuit model of the target battery; the battery management system includes a data acquisition module and an active balancing circuit; the data acquisition module is used to monitor the individual cell voltages and total current of multiple cells in the target battery in real time. The method includes steps 202 to 208. Wherein:

[0055] Step 202: Switch the operating mode of the target battery multiple times, and collect the individual cell voltage and total current of multiple individual cells of the target battery at the moment of switching the operating mode.

[0056] The operating modes include charging mode, driving mode, and idle mode. The target battery can be a lithium battery.

[0057] For example, the instant of the operating mode switch is the instant of a step change in the current of the target battery.

[0058] Step 204: Based on the individual cell voltage and total current, correct the ohmic internal resistance parameter of the target battery in the equivalent circuit model.

[0059] For example, a linear regression model is established based on the single cell voltage and total current of the target battery to calculate the ohmic internal resistance parameter of the target battery; if the calculated ohmic internal resistance parameter is different from the ohmic internal resistance parameter in the equivalent circuit model, the ohmic internal resistance parameter of the target battery is corrected in the equivalent circuit model.

[0060] Optionally, the ohmic internal resistance parameter of the target battery can be corrected based on the above-mentioned method of establishing a linear regression model, or parameter identification algorithms such as recursive least squares method or Kalman filtering can be used instead. All of the above algorithms can achieve decoupling of polarization voltage.

[0061] Step 206: After correcting the ohmic internal resistance parameter, if the active balancing circuit is activated, the cumulative balancing time of multiple individual cells in the target battery is continuously acquired.

[0062] The active balancing circuit automatically activates when there are differences in the open-circuit voltage of the individual cells in the target battery.

[0063] For example, since the ohmic internal resistance parameter has been corrected, it can be ensured that the activation of the active balancing circuit is based on the consistency of the actual open-circuit voltage of the target battery. If the active balancing circuit is activated, the cumulative balancing time of multiple individual cells in the target battery will be continuously acquired.

[0064] Step 208: Based on the cumulative equalization time, determine whether there is a faulty single cell in the target battery that has experienced an internal short circuit.

[0065] Among them, the faulty single cell is the single cell in the target battery that has experienced an internal short circuit fault.

[0066] For example, for each individual cell, if the cumulative equalization time is greater than a preset threshold, then the individual cell is a faulty individual cell that has experienced an internal short circuit fault.

[0067] In the aforementioned method for diagnosing internal short-circuit faults in batteries, the operating mode of the target battery is switched multiple times, and the individual cell voltages and total currents of multiple cells in the target battery are collected at the moment of each mode switch. Based on the individual cell voltages and total currents, the ohmic internal resistance parameters of the target battery are corrected in the equivalent circuit model. This correction process eliminates the interference of polarization voltage on measurement accuracy, ensuring that the equalization strategy is based on the consistency of the battery's actual open-circuit voltage rather than simply the consistency of the terminal voltage, thereby preventing false equalization. After correcting the ohmic internal resistance parameters, if the active equalization circuit is activated, the cumulative equalization time of multiple cells in the target battery is continuously acquired. Based on the cumulative equalization time, it is determined whether there are any faulty cells in the target battery that have experienced internal short-circuit faults. This method enables online identification of internal short-circuit faults while the target battery is continuously equalizing and eliminating inconsistencies, without interrupting the equalization operation for diagnosis, thus ensuring the safety of the target battery pack at all times.

[0068] In an exemplary embodiment, determining whether there is a faulty single cell in the target battery that has experienced an internal short circuit based on the cumulative equalization time includes: comparing the cumulative equalization time of multiple single cells with a preset threshold; if the cumulative equalization time is greater than the preset threshold, the single cell corresponding to the cumulative equalization time is regarded as the faulty single cell that has experienced an internal short circuit.

[0069] For example, if there is a faulty single cell, the faulty single cell will continuously consume energy when the active balancing circuit is activated, so that when it reaches voltage balance, the energy injected by the active balancing circuit is much greater than that of the normal single cell. Therefore, the cumulative balancing time of the faulty single cell is much longer than that of the normal single cell.

[0070] For example, the cumulative equalization time of multiple individual cells is compared with a preset threshold one by one. For each individual cell, if the cumulative equalization time is greater than the preset threshold, the individual cell is determined to be a faulty individual cell.

[0071] In this embodiment, by comparing the cumulative balancing time with a preset threshold, the active balancing circuit of the target battery can be used to easily determine whether there is a faulty single cell with an internal short circuit fault, ensuring that the diagnostic function can run online in real time.

[0072] In one embodiment, the equivalent circuit model includes an internal short-circuit resistance; the method further includes: selecting an equalization time window within the cumulative equalization time of the faulty single cell; constructing an energy conservation quantification equation based on the energy changes of the active equalization circuit and the target cell within the equalization time window; and calculating the specific value of the internal short-circuit resistance based on the energy conservation quantification equation.

[0073] Among them, such as Figure 3 As shown, the equivalent circuit model includes a simple internal resistance (Rint) model of the target battery and an internal short-circuit resistance. The internal short-circuit resistance is connected in parallel with the simple internal resistance model to simulate the leakage path of the target battery.

[0074] For example, an equilibration time window is arbitrarily selected within the cumulative equilibration time of the faulty single cell; the energy changes of the active equilibration circuit and the target cell within the equilibration time window are obtained; based on the energy changes of the active equilibration circuit and the target cell within the equilibration time window, an energy conservation quantification equation is constructed; based on the energy conservation quantification equation, the difference between the injected energy and the normal loss is the heat loss of the internal short-circuit resistance; based on the heat loss of the internal short-circuit resistance, the specific value of the internal short-circuit resistance is calculated.

[0075] In this embodiment, by constructing the energy conservation quantification equation and calculating the specific value of the internal short-circuit resistance, the fault is accurately quantified and graded. The degree of internal short circuit of the faulty single cell can be accurately quantified, and a fine-grained graded safety strategy can be implemented according to the specific value of the internal short-circuit resistance, such as early warning maintenance or immediate circuit disconnection. This greatly improves the safety decision-making level of the system and avoids accidents caused by false alarms or missed alarms.

[0076] In one embodiment, an energy conservation quantification equation is constructed based on the energy changes of the active balancing circuit and the target battery within the balancing time window. This includes: obtaining the balancing energy injected by the active balancing circuit within the balancing time window, as well as the energy changes and external work done by the target battery within the balancing time window; analyzing the relationship between the balancing energy, the energy changes of the target battery, and the external work done, and constructing the energy conservation quantification equation.

[0077] The active balancing circuit includes a flyback converter. Because the active balancing circuit contains a flyback converter, the energy injected into the target battery can be precisely adjusted by controlling the duty cycle and frequency of the pulse width modulation (PWM) of the primary-side switching transistors of the flyback converter. Simultaneously, the energy is integrated and metered based on the current sampling value. Therefore, the active balancing circuit is used to control precise energy injection and energy metering.

[0078] Optionally, the balancing energy injected by the active balancing circuit within the balancing time window, as well as the energy change and external power output of the target battery within the balancing time window, can be directly obtained at the terminal.

[0079] In this embodiment, by establishing a balance between the energy injected, the battery's own energy changes, and the external work output, the specific value of the internal short-circuit resistance can be directly calculated.

[0080] In one of the most specific embodiments, such as Figure 4 As shown, the battery internal short-circuit fault diagnosis method described in this application is applied to a battery management system. The system includes a data acquisition module, an active balancing circuit, and a controller located at the terminal, i.e., a fault diagnosis module. The terminal executes the battery internal short-circuit fault diagnosis method, including:

[0081] Perform online internal resistance compensation steps: By identifying whether the battery is in charging, driving, or idle mode, a linear regression model is constructed using the voltage response at the moment of mode switching (i.e., when the current changes stepwise); based on the linear regression model, the ohmic internal resistance parameter of the target battery is corrected in real time.

[0082] Fault diagnosis steps: After performing the online internal resistance compensation step, when active balancing is started, the terminal will continuously count the cumulative balancing time of each individual cell; for any individual cell, if the cumulative balancing time exceeds the preset threshold, the terminal will determine that the individual cell has an internal short circuit fault.

[0083] The quantitative calculation steps are as follows: A balancing time window is selected, and the balancing energy injected by the active balancing circuit recorded by the terminal within this window is compared with the energy changes of the target battery itself and the energy used externally. An energy conservation quantitative equation is then established. In this equation, the absolute value of the difference between the injected energy and normal losses is the heat loss from the internal short-circuit resistance. The terminal will then calculate the specific internal short-circuit resistance value based on this.

[0084] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0085] Based on the same inventive concept, this application also provides a battery management system for implementing the aforementioned battery internal short-circuit fault diagnosis method. The solution provided by this device is similar to the implementation described in the above method; therefore, the specific limitations in one or more battery management system embodiments provided below can be found in the limitations of the battery internal short-circuit fault diagnosis method described above, and will not be repeated here.

[0086] In one exemplary embodiment, such as Figure 5 As shown, a battery management system 500 is provided, which operates on an equivalent circuit model of a target battery. The system includes a data acquisition module 502, an active balancing circuit 504, and a fault diagnosis module 506. The data acquisition module 502 is used to monitor the individual cell voltages and total current of multiple cells in the target battery in real time. The fault diagnosis module 506 is used for:

[0087] The target battery's operating mode is switched multiple times, and the individual cell voltage and total current of multiple cells in the target battery are collected at the moment of the operating mode switch.

[0088] Based on the individual cell voltage and total current, the ohmic internal resistance parameter of the target battery is corrected in the equivalent circuit model.

[0089] After correcting the ohmic internal resistance parameter, if the active balancing circuit 504 is activated, it will continuously acquire the cumulative balancing time of multiple individual cells in the target battery.

[0090] Based on the cumulative equalization time, determine whether there are faulty individual cells in the target battery that have experienced internal short circuit faults.

[0091] In one embodiment, the fault diagnosis module 506 is further configured to compare the cumulative equalization time of multiple individual cells with a preset threshold; if the cumulative equalization time is greater than the preset threshold, the individual cell corresponding to the cumulative equalization time is regarded as the faulty individual cell that has experienced an internal short circuit fault.

[0092] In one embodiment, the fault diagnosis module 506 is further configured to select an equalization time window within the cumulative equalization time of the faulty individual battery; construct an energy conservation quantification equation based on the active equalization circuit 504 and the energy change of the target battery within the equalization time window; and calculate the specific value of the internal short-circuit resistance based on the energy conservation quantification equation.

[0093] In one embodiment, the fault diagnosis module 506 is also used to obtain the equalization energy injected by the active equalization circuit 504 within the equalization time window, as well as the energy change and external work of the target battery within the equalization time window; analyze the relationship between the equalization energy, the energy change of the target battery and the external work, and construct an energy conservation quantification equation.

[0094] In one embodiment, the active balancing circuit 504 includes a primary winding, a secondary winding, and a flyback converter; the primary winding is connected to the total positive and negative terminals of the target battery; the secondary winding is connected to multiple individual cells of the target battery; and the flyback converter is used to control the energy injected into the target battery by the active balancing circuit 504.

[0095] The active balancing circuit 504 adopts a flyback converter topology; the primary winding is connected to the total positive and negative terminals of the target battery; the secondary winding is connected to each individual cell of the target battery through a gating switch matrix composed of metal oxide semiconductor field-effect transistors (MOSFETs) or relays.

[0096] For example, when a faulty cell is in a high state of charge (High SOC), in order to prevent overvoltage caused by forced equalization, the battery management system 500 will automatically adjust the PWM duty cycle to reduce the equalization current, or suspend the equalization of the cell by means of a bypass switch until its voltage drops back to a safe range.

[0097] Alternatively, the flyback converter can be replaced with other active balancing topologies with energy metering capabilities, such as bidirectional DC-DC converters, step-up transformers, or switched capacitors.

[0098] In this embodiment, the active balancing circuit establishes an energy transmission channel from the battery pack to individual cells through this "one primary side, multiple secondary sides" connection relationship, which enables precise energy transfer between individual cells, minimizes energy loss during the balancing process, and provides stable and reliable energy data support for internal short circuit fault diagnosis.

[0099] In one embodiment, the data acquisition module 502 includes a voltage acquisition circuit and a current sensor; the data acquisition module 502 is also used to acquire the primary current and primary voltage of the active balancing circuit.

[0100] In this embodiment, the data acquisition module can accurately capture the millivolt-level voltage fluctuations of each individual battery cell through the voltage acquisition circuit, while the current sensor can monitor the dynamic changes of the total current and the primary-side current of the active balancing circuit in real time. Together, they provide high-precision and timely basic data support for fault diagnosis. Simultaneously, the individual cell voltage, total current, primary-side current, and voltage data acquired by the data acquisition unit accurately reflect the actual operating state of the battery, providing a reliable data foundation for subsequent diagnostic steps such as ohmic internal resistance parameter correction and internal short-circuit resistance calculation.

[0101] The modules in the aforementioned battery management system can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the corresponding operations of each module.

[0102] In one exemplary embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 6As shown, this computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operating system and computer programs stored in the non-volatile storage media. The database stores data on individual cell voltages, total current, primary-side current, and primary-side voltage. The I / O interfaces are used for information exchange between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When executed by the processor, the computer program implements a method for diagnosing internal short-circuit faults in a battery.

[0103] Those skilled in the art will understand that Figure 6 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0104] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0105] The target battery's operating mode is switched multiple times, and the individual cell voltage and total current of multiple cells in the target battery are collected at the moment of the operating mode switch.

[0106] Based on the individual cell voltage and total current, the ohmic internal resistance parameter of the target battery is corrected in the equivalent circuit model.

[0107] After correcting the ohmic internal resistance parameter, if the active balancing circuit is activated, the cumulative balancing time of multiple individual cells in the target battery will be continuously acquired.

[0108] Based on the cumulative equalization time, determine whether there are faulty individual cells in the target battery that have experienced internal short circuit faults.

[0109] In one embodiment, when the processor executes the computer program, it further performs the following steps: comparing the cumulative equalization time of multiple individual cells with a preset threshold; if the cumulative equalization time is greater than the preset threshold, the individual cell corresponding to the cumulative equalization time is identified as the faulty individual cell that has experienced an internal short circuit fault.

[0110] In one embodiment, when the processor executes the computer program, it further performs the following steps: selecting an equalization time window within the cumulative equalization time of the faulty individual battery; constructing an energy conservation quantification equation based on the active equalization circuit and the energy change of the target battery within the equalization time window; and calculating the specific value of the internal short-circuit resistance based on the energy conservation quantification equation.

[0111] In one embodiment, when the processor executes the computer program, it also performs the following steps: acquiring the equalization energy injected by the active equalization circuit within the equalization time window, as well as the energy change and external work output of the target battery within the equalization time window; analyzing the relationship between the equalization energy, the energy change of the target battery, and the external work output, and constructing an energy conservation quantification equation.

[0112] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0113] The target battery's operating mode is switched multiple times, and the individual cell voltage and total current of multiple cells in the target battery are collected at the moment of the operating mode switch.

[0114] Based on the individual cell voltage and total current, the ohmic internal resistance parameter of the target battery is corrected in the equivalent circuit model.

[0115] After correcting the ohmic internal resistance parameter, if the active balancing circuit is activated, the cumulative balancing time of multiple individual cells in the target battery will be continuously acquired.

[0116] Based on the cumulative equalization time, determine whether there are faulty individual cells in the target battery that have experienced internal short circuit faults.

[0117] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: comparing the cumulative equalization time of multiple individual cells with a preset threshold; if the cumulative equalization time is greater than the preset threshold, the individual cell corresponding to the cumulative equalization time is identified as the faulty individual cell that has experienced an internal short circuit fault.

[0118] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: selecting an equalization time window within the cumulative equalization time of the faulty individual battery; constructing an energy conservation quantification equation based on the active equalization circuit and the energy change of the target battery within the equalization time window; and calculating the specific value of the internal short-circuit resistance based on the energy conservation quantification equation.

[0119] In one embodiment, when the computer program is executed by the processor, it also performs the following steps: acquiring the equalization energy injected by the active equalization circuit within the equalization time window, as well as the energy change and external work output of the target battery within the equalization time window; analyzing the relationship between the equalization energy, the energy change of the target battery, and the external work output, and constructing an energy conservation quantification equation.

[0120] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, performs the following steps:

[0121] The target battery's operating mode is switched multiple times, and the individual cell voltage and total current of multiple cells in the target battery are collected at the moment of the operating mode switch.

[0122] Based on the individual cell voltage and total current, the ohmic internal resistance parameter of the target battery is corrected in the equivalent circuit model.

[0123] After correcting the ohmic internal resistance parameter, if the active balancing circuit is activated, the cumulative balancing time of multiple individual cells in the target battery will be continuously acquired.

[0124] Based on the cumulative equalization time, determine whether there are faulty individual cells in the target battery that have experienced internal short circuit faults.

[0125] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: comparing the cumulative equalization time of multiple individual cells with a preset threshold; if the cumulative equalization time is greater than the preset threshold, the individual cell corresponding to the cumulative equalization time is identified as the faulty individual cell that has experienced an internal short circuit fault.

[0126] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: selecting an equalization time window within the cumulative equalization time of the faulty individual battery; constructing an energy conservation quantification equation based on the active equalization circuit and the energy change of the target battery within the equalization time window; and calculating the specific value of the internal short-circuit resistance based on the energy conservation quantification equation.

[0127] In one embodiment, when the computer program is executed by the processor, it also performs the following steps: acquiring the equalization energy injected by the active equalization circuit within the equalization time window, as well as the energy change and external work output of the target battery within the equalization time window; analyzing the relationship between the equalization energy, the energy change of the target battery, and the external work output, and constructing an energy conservation quantification equation.

[0128] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0129] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0130] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0131] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for diagnosing internal short circuit faults in a battery, characterized in that, It is applied to a battery management system; the battery management system operates on an equivalent circuit model of the target battery; the battery management system includes a data acquisition module and an active balancing circuit; The data acquisition module is used to monitor the individual cell voltage and total current of multiple cells in the target battery in real time; the method includes: The operating mode of the target battery is switched multiple times, and the individual cell voltage and total current of multiple individual cells of the target battery are collected at the moment of switching the operating mode. Based on the individual cell voltage and total current, the ohmic internal resistance parameter of the target battery is corrected in the equivalent circuit model. After correcting the ohmic internal resistance parameter, if the active balancing circuit is activated, the cumulative balancing time of multiple individual cells in the target battery is continuously acquired. Based on the cumulative equalization time, it is determined whether there is a faulty single cell in the target battery that has experienced an internal short circuit.

2. The method according to claim 1, characterized in that, The step of determining whether there is a faulty individual cell with an internal short circuit fault in the target battery based on the cumulative equalization time includes: The cumulative equalization time of the multiple individual cells is compared with a preset threshold. If the cumulative equalization time is greater than the preset threshold, the cell corresponding to the cumulative equalization time is identified as the faulty cell that has experienced an internal short circuit fault.

3. The method according to claim 1, characterized in that, The equivalent circuit model includes an internal short-circuit resistance; the method further includes: An equalization time window is selected within the cumulative equalization time of the faulty individual cell. Based on the energy changes of the active balancing circuit and the target battery within the balancing time window, an energy conservation quantification equation is constructed. Based on the energy conservation quantification equation, the specific value of the internal short-circuit resistance is calculated.

4. The method according to claim 3, characterized in that, The energy conservation quantification equation is constructed based on the energy changes of the active balancing circuit and the target battery within the balancing time window, including: The active balancing circuit injects balancing energy within the balancing time window, as well as the energy change and external functional capacity of the target battery within the balancing time window, are obtained. The relationship between the equilibrium energy, the energy change of the target battery, and the external work output is analyzed to construct an energy conservation quantification equation.

5. A battery management system, characterized in that, The battery management system operates on an equivalent circuit model of the target battery; the battery management system includes a data acquisition module and an active balancing circuit; the data acquisition module is used to monitor the individual cell voltage and total current of multiple cells in the target battery in real time; the battery management system also includes a fault diagnosis module, which is used for: The operating mode of the target battery is switched multiple times, and the individual cell voltage and total current of multiple individual cells of the target battery are collected at the moment of switching the operating mode. Based on the individual cell voltage and total current, the ohmic internal resistance parameter of the target battery is corrected in the equivalent circuit model. After correcting the ohmic internal resistance parameter, if the active balancing circuit is activated, the cumulative balancing time of multiple individual cells in the target battery is continuously acquired. Based on the cumulative equalization time, it is determined whether there is a faulty single cell in the target battery that has experienced an internal short circuit.

6. The system according to claim 5, characterized in that, The active balancing circuit includes a primary winding, a secondary winding, and a flyback converter; the primary winding is connected to the total positive and negative terminals of the target battery; the secondary winding is connected to multiple individual cells of the target battery; and the flyback converter is used to control the energy injected into the target battery by the active balancing circuit.

7. The system according to claim 5, characterized in that, The data acquisition module includes a voltage acquisition circuit and a current sensor; the data acquisition module is also used to acquire the primary current and primary voltage of the active balancing circuit.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 4.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 4.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 4.

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