Electrochemical energy storage plant external short circuit fault isolation system and method

Abstract

The application provides an external short-circuit fault isolation system and method of an electrochemical energy storage power station, and applies to the technical field of battery detection. The system comprises a converter, a plurality of battery clusters, a plurality of battery modules and a plurality of circuit breakers, the plurality of battery modules and the plurality of circuit breakers are alternately electrically connected, and a battery management module. For any battery cluster: according to the discharge current and the discharge voltage of the plurality of battery modules, the dynamic conduction virtual impedance of the plurality of battery modules is determined; according to the plurality of dynamic conduction virtual impedances and the short-circuit fault condition determined based on the open-circuit voltage and the internal resistance voltage drop of the battery module, the fault battery module in the short-circuit fault state is determined; according to the discharge current of the fault battery module and the circuit breaking current threshold of the target circuit breaker corresponding to the target fault battery module, the target control signal is generated and sent to the target circuit breaker, so that the fault battery module in the short-circuit fault state is isolated from other battery modules in the normal state.

Description

Technical Field

[0001] This invention relates to the field of battery testing technology, and more specifically to an external short-circuit fault isolation system and method for an electrochemical energy storage power station. Background Technology

[0002] Energy storage power stations can be equipped with multiple battery clusters, each containing multiple battery cells connected in series. These multiple battery modules, all in a stable discharge state, can provide a large and stable amount of power to the power station. However, there is a risk of short circuits and other faults during battery module operation. Therefore, when a battery module experiences a short circuit, it is necessary to isolate it from other normal battery modules promptly.

[0003] In the process of realizing the above-mentioned inventive concept, it was found through research that: when a short circuit fault occurs in the battery module, the relevant technology is difficult to cover the full short circuit current range corresponding to the battery short circuit fault, which makes it impossible to isolate the faulty battery module in a timely and effective manner. At the same time, in the process of isolating the faulty battery module, it is difficult to accurately locate the position of the faulty battery module. Summary of the Invention

[0004] In view of the above problems, the present invention provides an external short-circuit fault isolation system and method for electrochemical energy storage power stations.

[0005] According to a first aspect of the present invention, an external short-circuit fault isolation system for an electrochemical energy storage power station is provided, comprising: a converter for converting initial power supply energy into target power supply energy; multiple battery clusters electrically connected to the converter, each battery cluster comprising multiple battery modules and multiple circuit breakers, the multiple battery modules and multiple circuit breakers being alternately electrically connected; multiple battery modules of the multiple battery clusters for providing initial power supply energy to the converter; and a battery management module electrically connected to the multiple battery clusters for, for, targeting any battery cluster: based on the discharge current and discharge voltage of the multiple battery modules... The system determines the dynamic on-state virtual impedance of multiple battery modules. Based on the multiple dynamic on-state virtual impedances and the short-circuit fault conditions determined by the open-circuit voltage and internal resistance voltage drop of the battery modules, it identifies the faulty battery module in a short-circuit fault state from among the multiple battery modules. Based on the discharge current of the faulty battery module and the breaking current threshold of the target circuit breaker corresponding to the target faulty battery module, it generates a target control signal and sends it to the target circuit breaker to switch the connection state between multiple battery modules, thereby isolating the faulty battery module in a short-circuit fault state from other battery modules in a normal state.

[0006] A second aspect of the present invention provides a method for isolating external short-circuit faults in an electrochemical energy storage power station, comprising: for any battery cluster, determining the dynamic conduction virtual impedance of multiple battery modules based on the discharge current and discharge voltage of multiple battery modules; determining the faulty battery module in a short-circuit fault state from the multiple battery modules based on the multiple dynamic conduction virtual impedances and short-circuit fault conditions determined based on the open-circuit voltage and internal resistance voltage drop of the battery modules; generating a target control signal and sending it to the target circuit breaker based on the discharge current of the faulty battery module and the breaking current threshold of the target circuit breaker corresponding to the target faulty battery module, so as to switch the connection state between the multiple battery modules, thereby isolating the faulty battery module in a short-circuit fault state from other battery modules in a normal state.

[0007] A third aspect of the present invention provides an electronic device comprising: one or more processors; and a memory for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors perform the method described above.

[0008] A fourth aspect of the present invention also provides a computer-readable storage medium having executable instructions stored thereon, which, when executed by a processor, cause the processor to perform the methods described above.

[0009] A fifth aspect of the invention also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0010] According to the external short-circuit fault isolation system and method for an electrochemical energy storage power station of the present invention, the external short-circuit fault isolation system of the electrochemical energy storage power station may include a converter, multiple battery clusters electrically connected to the converter, and a battery management module electrically connected to the multiple battery clusters. Each battery cluster may include multiple battery modules and multiple circuit breakers that are alternately electrically connected. During the process of each battery module discharging to provide initial power to the converter, the battery management module can monitor the discharge current and discharge voltage of each battery module in real time and calculate the dynamic on-state virtual impedance of each battery module. Based on the short-circuit fault conditions pre-determined by analyzing the open-circuit voltage and internal resistance voltage drop of the battery module, the real-time dynamic on-state virtual impedance of each battery module is used to determine the short-circuit fault, thereby identifying the battery modules that meet the short-circuit fault conditions as faulty battery modules in a short-circuit fault state.

[0011] After identifying a faulty battery module in a short-circuit fault state, based on the circuit breaker and the protection device within the battery module jointly determined by the circuit breaker and the protection device, it is determined whether the faulty battery module should be disconnected from other normal battery modules by the target circuit breaker corresponding to the faulty battery module, or by the protection device within the faulty battery module. Based on the judgment, a target control signal is generated and sent to the target circuit breaker. This achieves the goal of using multiple circuit breakers and the protection device within each battery module to jointly address potential short-circuit faults in the battery module, improving the response range across the entire lifecycle. Furthermore, since each battery module is equipped with a corresponding circuit breaker, combined with the battery management system's short-circuit fault judgment based on dynamic conduction virtual impedance, even among multiple battery modules connected in series, the faulty battery module can be easily, accurately, and efficiently located and isolated. This improves the operational reliability, robustness, and risk resistance of the energy storage power station, facilitating its widespread application in actual industrial production and expanding the applicable scenarios and scope of the proposed early warning method. Attached Figure Description

[0012] The above-mentioned contents, as well as other objects, features and advantages of the present invention, will become clearer from the following description of embodiments of the present invention with reference to the accompanying drawings.

[0013] Figure 1 A schematic diagram of an external short-circuit fault isolation system for an electrochemical energy storage power station according to an embodiment of the present invention is shown.

[0014] Figure 2 A schematic diagram of a battery module according to an embodiment of the present invention is shown.

[0015] Figure 3 A schematic diagram of a faulty battery module in a short-circuit fault state according to an embodiment of the present invention is shown.

[0016] Figure 4 A schematic diagram of the current cut-off range of a circuit breaker and a fuse according to an embodiment of the present invention is shown.

[0017] Figure 5 A flowchart of an external short-circuit fault isolation method for an electrochemical energy storage power station according to an embodiment of the present invention is shown.

[0018] Figure 6 A flowchart of a method for generating a target control signal according to an embodiment of the present invention is shown. Detailed Implementation

[0019] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the invention. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the invention for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0020] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0021] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0022] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).

[0023] In the technical solution of this invention, the user information (including but not limited to user personal information, user image information, user device information, such as location information) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, storage, use, processing, transmission, provision, disclosure, and application of related data all comply with relevant laws, regulations, and standards, take necessary confidentiality measures, do not violate public order and good morals, and provide corresponding operation entry points for users to choose to authorize or refuse.

[0024] Energy storage power stations can be equipped with multiple battery clusters for generating renewable energy. Each cluster can contain multiple lithium battery modules connected in series. Lithium battery modules offer advantages such as fast charging, high energy density, and long lifespan. By switching between charging and discharging states, multiple lithium battery modules can provide a large and stable power supply. When a battery module experiences a short-circuit fault, it is necessary to promptly isolate the faulty module from the other normal battery modules.

[0025] However, due to technical limitations in the protection systems of energy storage power stations, it is impossible to isolate faulty lithium battery modules. In the process of realizing the above-mentioned inventive concept, research revealed that: when a short-circuit fault occurs in a battery module, the relevant technology struggles to cover the full short-circuit current range corresponding to the battery short-circuit fault, resulting in the inability to isolate the faulty battery module in a timely and effective manner. Furthermore, during the isolation process, it is difficult to accurately locate the faulty battery module.

[0026] In view of this, embodiments of the present invention provide an external short-circuit fault isolation system for an electrochemical energy storage power station, comprising: a converter for converting initial power supply energy into target power supply energy; multiple battery clusters electrically connected to the converter, each battery cluster comprising multiple battery modules and multiple circuit breakers, the multiple battery modules and multiple circuit breakers being alternately electrically connected; multiple battery modules of the multiple battery clusters for providing initial power supply energy to the converter; and a battery management module electrically connected to the multiple battery clusters for managing any battery cluster based on the discharge current and discharge voltage of the multiple battery modules. The system determines the dynamic on-state virtual impedance of multiple battery modules. Based on the multiple dynamic on-state virtual impedances and the short-circuit fault conditions determined by the open-circuit voltage and internal resistance voltage drop of the battery modules, it identifies the faulty battery module in a short-circuit fault state from among the multiple battery modules. Based on the discharge current of the faulty battery module and the breaking current threshold of the target circuit breaker corresponding to the target faulty battery module, it generates a target control signal and sends it to the target circuit breaker to switch the connection state between multiple battery modules, thereby isolating the faulty battery module in a short-circuit fault state from other battery modules in a normal state.

[0027] Figure 1 A schematic diagram of an external short-circuit fault isolation system for an electrochemical energy storage power station according to an embodiment of the present invention is shown.

[0028] like Figure 1 As shown, the external short-circuit fault isolation system of an electrochemical energy storage power station may include a converter, multiple battery clusters, and a battery management module. Figure 1 The figure shows M battery clusters, each of which may include N battery modules and N circuit breakers. The Nth circuit breaker in each battery cluster is not shown in the figure.

[0029] Specifically, a converter can be used to convert initial power supply energy into target power supply energy.

[0030] The input terminal of the inverter can be electrically connected to the output terminals of multiple battery clusters. Multiple battery modules within the multiple battery clusters switch between charging and discharging states to provide initial power to the inverter. This allows the inverter to perform various forms of power conversion, such as AC-DC and DC-DC conversion, to obtain the target power.

[0031] Multiple battery clusters can be electrically connected to the converter. Each battery cluster includes multiple battery modules and multiple circuit breakers, which are alternately electrically connected. The multiple battery modules of the multiple battery clusters are used to provide initial power to the converter.

[0032] A battery cluster can be a collection of batteries formed by connecting multiple battery modules in series or in parallel. Each electrochemical energy storage power station can contain multiple battery clusters, and each battery cluster can include multiple battery modules and multiple circuit breakers that are alternately electrically connected to the multiple battery modules.

[0033] Each battery module supplies power to the outside via an inverter by switching between charging and discharging states. In this invention, the battery cluster is an example of multiple battery cells connected in series. A battery cell can be characterized as a single battery unit. The initial power supply can be the discharge current and discharge voltage provided by each battery module in the discharging state.

[0034] A circuit breaker is a device used to isolate a faulty battery module from other normal battery modules in response to the control of the battery management system when a short-circuit fault occurs in the battery module. By using an independent circuit breaker located outside the battery module, in conjunction with other protection devices built into the battery module, full-range dual-coverage protection is provided for the short-circuit current that may be involved in the battery module.

[0035] The battery management module can be electrically connected to multiple battery clusters. For any given battery cluster, it determines the dynamic on-state virtual impedance of multiple battery modules based on their discharge current and discharge voltage. Based on the multiple dynamic on-state virtual impedances and the short-circuit fault conditions determined by the open-circuit voltage and internal resistance voltage drop of the battery modules, it identifies the faulty battery module in a short-circuit fault state from among the multiple battery modules. Based on the discharge current of the faulty battery module and the breaking current threshold of the target circuit breaker corresponding to the target faulty battery module, it generates a target control signal and sends it to the target circuit breaker to switch the connection state between the multiple battery modules, thus isolating the faulty battery module in a short-circuit fault state from other battery modules in a normal state.

[0036] The battery management module of the energy storage power station can monitor and control each battery module and each circuit breaker in each battery cluster in real time. In the event of a short circuit fault in any battery module, the faulty battery module can be disconnected in time to prevent the faulty battery module from further damaging other normal battery modules.

[0037] Existing short-circuit fault identification typically relies on overcurrent protection or undervoltage protection methods that judge faults based on fixed voltage and current thresholds. However, short-circuit current and short-circuit voltage can vary with factors such as the state of charge, state of health, operating conditions, and short-circuit resistance of the battery module. Therefore, the above-mentioned protection methods are difficult to reliably identify external short-circuit faults in the battery module throughout its entire life cycle and under various complex environments.

[0038] Based on this, by collecting the discharge current and discharge voltage of each battery module in real time at various moments, the dynamic on-state virtual impedance of each battery module is calculated. According to the dynamic on-state virtual impedance of each battery module and the pre-determined short-circuit fault conditions, the short-circuit fault is determined and located for each battery module. When a battery module is determined to be in an external short-circuit fault state, the current cutoff range between the circuit breaker and other protection devices within the battery module is considered to determine whether the circuit breaker should disconnect the circuit. If it is determined that the circuit breaker should disconnect the circuit, a target control signal is generated and sent to the corresponding target circuit breaker, thereby isolating the faulty battery module in a short-circuit fault state from other battery modules in a normal state.

[0039] According to embodiments of the present invention, the external short-circuit fault isolation system of an electrochemical energy storage power station may include a converter, multiple battery clusters electrically connected to the converter, and a battery management module electrically connected to the multiple battery clusters. Each battery cluster may include multiple battery modules and multiple circuit breakers that are alternately electrically connected. During the process of each battery module discharging to provide initial power to the converter, the battery management module can monitor the discharge current and discharge voltage of each battery module in real time and calculate the dynamic on-state virtual impedance of each battery module. Based on the short-circuit fault conditions pre-determined by analyzing the open-circuit voltage and internal resistance voltage drop of the battery module, the real-time dynamic on-state virtual impedance of each battery module is used to determine the short-circuit fault, thereby identifying the battery modules that meet the short-circuit fault conditions as faulty battery modules in a short-circuit fault state.

[0040] After identifying a faulty battery module in a short-circuit fault state, based on the circuit breaker and the protection device within the battery module jointly determined by the circuit breaker and the protection device within the battery module, it is determined whether the faulty battery module should be disconnected from other normal battery modules by the target circuit breaker corresponding to the faulty battery module, or by the protection device within the faulty battery module. Based on the judgment, a target control signal is generated and sent to the target circuit breaker. This achieves the goal of utilizing multiple circuit breakers and the protection device within each battery module to jointly address potential short-circuit faults in the battery module, improving the response range across the entire lifecycle. Furthermore, since each battery module is equipped with a corresponding circuit breaker, combined with the battery management system's short-circuit fault judgment based on dynamic conduction virtual impedance, even among multiple battery modules connected in series, the faulty battery module can be easily, accurately, and efficiently located and isolated. This improves the operational reliability, robustness, and risk resistance of the energy storage power station, facilitating its widespread application in actual industrial production and expanding the applicable scenarios and scope of the early warning method proposed in this invention.

[0041] According to an embodiment of the present invention, a method for determining the battery voltage change of multiple battery cells based on the discharge voltage of multiple battery cells in any battery cluster, and for performing fault trigger judgment on multiple battery cells respectively based on the discharge current and battery voltage change of multiple battery cells, to obtain multiple fault trigger results of multiple battery cells may include the following operations.

[0042] Figure 2 A schematic diagram of a battery module according to an embodiment of the present invention is shown.

[0043] like Figure 2 As shown, in Figure 1 Based on the system shown, any battery cluster may include N battery modules and N circuit breakers. Each battery module may include battery cells and fuses, where N ≥ n ≥ 2, and N and n are both integers.

[0044] Specifically, for the nth battery cell in the battery module, the first end of the nth battery cell can be electrically connected to the second end of the (n-1)th circuit breaker that is electrically connected to the (n-1)th battery module, the second end of the nth battery cell can be electrically connected to the first end of the nth fuse, and the nth battery cell can be used to provide initial power to the converter.

[0045] The nth fuse has its first terminal electrically connected to the second terminal of the nth battery cell. The second terminal of the nth fuse can be electrically connected to the first terminal of the nth circuit breaker, which is electrically connected to the nth battery module. The nth fuse can be used to disconnect the nth battery cell from the other N-1 battery cells when the discharge current of the nth battery cell is greater than the minimum rated fusing current, thereby isolating the nth battery cell in a short-circuit fault state.

[0046] In this configuration, the first end of the first battery cell in any battery cluster is electrically connected to the first end of the first battery cell in other battery clusters, and the second end of the Nth fuse in any battery cluster is electrically connected to the converter.

[0047] For the first battery module within each battery cluster, the first end of the first battery cell within each battery module can be electrically connected to the first common bus (i.e., equivalent to the first end of each battery cell in any battery cluster being electrically connected to the first end of the first battery cell in other battery clusters), and the second end of the first battery cell can be electrically connected to the first end of the first fuse. For the Nth battery module within each battery cluster, the first end of the Nth battery cell within each battery module can be electrically connected to the second end of the (N-1)th fuse, the second end of the Nth battery cell can be electrically connected to the first end of the Nth fuse, and the second end of the Nth fuse can be electrically connected to the second common bus (i.e., equivalent to the second end of the Nth fuse in any battery cluster being electrically connected to the converter). Both the first and second common buses can be electrically connected to the converter to allow the initial power supply to flow into the converter. Wherein, in Figure 2 The Nth fuse in each battery cluster is not shown.

[0048] By combining fuses and circuit breakers, the battery module can be protected against short-circuit currents with full coverage, thus isolating battery cells in a short-circuit fault state from those in a normal state in a timely manner.

[0049] According to embodiments of the present invention, each battery cluster may include multiple battery modules and multiple circuit breakers connected in alternating configurations. Each battery module may also include battery cells and fuses. While the battery cells are normally providing initial power to the inverter, the battery management system can monitor the discharge current of each battery cell. The fuses and circuit breakers configured for each battery cell work together to power the battery cells.

[0050] Figure 3 A schematic diagram of a faulty battery module in a short-circuit fault state according to an embodiment of the present invention is shown.

[0051] like Figure 3 As shown, in Figure 2 Based on the system shown, the energy storage power station can include M battery clusters, each of which can include N battery modules. Each battery module can be equipped with a fuse. An external short-circuit fault occurs between the first and second battery modules in the first battery cluster; that is, it's equivalent to a short-circuit resistor being connected externally to the first and second battery modules in the first battery cluster. This causes the first and second battery modules in the first battery cluster to be in a short-circuit fault state. For the multiple battery modules in normal states from the second to the Mth battery clusters, they can normally switch between power supply and discharge states, providing initial power to the converter. The converter then converts this initial power into the target power.

[0052] According to an embodiment of the present invention, the nth fuse can be configured as follows.

[0053] According to an embodiment of the present invention, based on the ampere-second characteristics and the cutting time of the nth circuit breaker, the minimum short-circuit current of the nth battery cell is determined according to the rated discharge cutoff voltage and rated discharge cutoff resistance of the nth battery cell, and the minimum short-circuit current of the nth battery cell is determined as the minimum rated fusing current of the nth fuse.

[0054] Among them, the rated discharge cutoff voltage represents the voltage when the battery cell is in its rated healthy state and the state of charge is at its minimum value, and the rated discharge cutoff resistance represents the internal resistance of the battery cell at the rated discharge cutoff voltage.

[0055] The ampere-second characteristic can be characterized as the relationship between the short-circuit current that a fuse can safely and quickly disconnect and the duration of the fuse's tripping. For the fuse and circuit breaker corresponding to the nth battery cell, it is necessary to ensure that the fuse and circuit breaker each separately perform interval isolation control of the short-circuit current across the entire range, while also ensuring that there is a small overlap in the short-circuit current monitoring range between the fuse and circuit breaker, so that there can be redundancy margin at the boundary between their respective responsible intervals.

[0056] Based on this, for the fuses inside the battery module, in order to ensure that the fuses can reliably interrupt the external short-circuit fault current, the ampere-second characteristics of the fuses need to meet the following requirements: when the discharge current of the battery cell is greater than or equal to the minimum short-circuit current in the fuse fault current range, the fuse can reliably melt the battery cell with the external short-circuit fault; when the discharge current of the battery cell is less than the minimum short-circuit current but greater than the maximum (allowable) discharge current of the battery cell, the fuse's melting time is less than the circuit breaker's breaking time; and when the discharge current of the battery cell is less than or equal to the maximum (allowable) discharge current of the battery cell, the fuse will not melt.

[0057] Therefore, based on the ampere-second characteristics of the fuse, the minimum short-circuit current of the battery cell corresponding to the fuse can be expressed as in formula (1).

[0058] (1);

[0059] Among them, I sc_min This can be characterized as the minimum short-circuit current of the battery cell, U ocv_min This can be characterized as the rated discharge cutoff voltage of a battery cell, that is, the voltage of the battery cell when SOH=100% (State of Health, the battery is in a healthy state) and SOC (State of Charge, the battery's state of charge) is at its minimum (when discharged to the lower cutoff voltage), R o_min It can be characterized as the rated discharge cutoff resistance of the battery cell, that is, the resistance of the battery cell when SOH=100% and SOC is at its minimum.

[0060] After calculating the minimum short-circuit current of the nth battery cell, this minimum short-circuit current can be determined as the minimum rated fusing current of the nth fuse.

[0061] According to an embodiment of the present invention, the maximum short-circuit current of the nth battery cell is determined based on the rated charging cut-off voltage and rated charging cut-off resistance of the nth battery cell.

[0062] The rated charging cut-off voltage represents the voltage when the battery cell is in its rated healthy state and its state of charge is at its maximum value, while the rated charging cut-off resistance represents the internal resistance of the battery cell at the rated charging cut-off voltage.

[0063] Based on the ampere-second characteristics of the above-mentioned fuse, the maximum short-circuit current of the battery cell corresponding to the fuse can be expressed as formula (2).

[0064] (2);

[0065] Among them, I sc_max This can be characterized as the maximum short-circuit current of the battery cell, U ocv_max This can be characterized as the rated charging cutoff voltage of the battery cell, that is, the voltage of the battery cell when SOH = 100% (the battery cell is in a healthy state) and SOC is at its minimum (when charged to the lower cutoff voltage), R o_max It can be characterized as the rated charging cutoff resistance of the battery cell, that is, the resistance of the battery cell when SOH=100% and SOC is at its minimum.

[0066] According to an embodiment of the present invention, the maximum rated operating current of the nth fuse is determined based on the maximum discharge current of the nth battery cell and a predetermined operating fusing factor; the maximum rated fusing current of the nth fuse is determined based on the maximum short-circuit current of the nth battery cell and a predetermined fusing amplification factor.

[0067] The maximum rated operating current of a fuse can be characterized as the maximum current that the fuse can continuously carry under specified conditions. To ensure the safe and reliable operation of the fuse in a battery pack with a predetermined operating load, the rated operating current of the fuse can be greater than or equal to the maximum continuous load current of the battery pack. The maximum (permissible) discharge current of a fuse can be characterized as the maximum continuous load current flowing through the battery cell on the DC side.

[0068] Based on this, according to the working characteristics of the fuse mentioned above, the maximum rated operating current of the fuse can be expressed as in formula (3).

[0069] (3);

[0070] Among them, I n This can be characterized by the maximum rated operating current of the fuse, k. n It can be characterized as the predetermined working circuit breaker factor, I b_n It can be characterized as the maximum discharge current of the battery cell, that is, the maximum (allowable) discharge current, wherein the predetermined working fusing factor can be set to 1.25, without any specific limitation.

[0071] The maximum rated fusing current of a fuse can be characterized as the maximum short-circuit current that the fuse can safely disconnect in a short period of time. In order to ensure that the fuse can reliably interrupt the external short-circuit fault current, the maximum rated fusing current of the fuse can be greater than the maximum short-circuit current of the battery cell, so as to ensure that the fuse can isolate the battery cell with a short-circuit fault from other battery cells in normal condition.

[0072] Based on this, according to the fusing characteristics of the above-mentioned fuse, the maximum rated fusing current of the fuse can be expressed as in formula (4).

[0073] (4);

[0074] Among them, I d_cu This can be characterized by the maximum rated fusing current of the fuse, k. cu It can be characterized as a predetermined fuse amplification factor, wherein the predetermined fuse amplification factor can be set to 1.1~1.2, without any specific limitation.

[0075] According to an embodiment of the present invention, the parameters of the nth initial fuse are configured based on the minimum rated fusing current, the maximum rated operating current, and the maximum rated fusing current of the nth fuse, to obtain the configured nth fuse.

[0076] The initial fuse can be characterized as a fuse that has not been configured with parameters. Based on the relevant fuse parameters confirmed above, the initial fuse is configured with parameters to obtain a configured fuse.

[0077] According to an embodiment of the present invention, based on the ampere-second characteristics between the fuse and the circuit breaker, the operating characteristics of the fuse, and the maximum breaking capacity, the parameters related to the fuse are determined and the fuse is configured according to the minimum and maximum short-circuit current that the battery cell can release, so as to use the fuse configured with the fault current breaking range to isolate and protect the battery cell from short-circuit faults.

[0078] According to an embodiment of the present invention, the nth circuit breaker can be configured as follows.

[0079] According to an embodiment of the present invention, the maximum rated operating current of the nth circuit breaker is determined based on the maximum discharge current of the nth battery cell and the first predetermined breaking capacity; the maximum short-time withstand current of the nth circuit breaker is determined based on the maximum short-circuit current of the nth battery cell and the second predetermined breaking capacity.

[0080] The maximum rated operating current of a circuit breaker can be characterized as the maximum current value that the circuit breaker can continuously carry under specified conditions. The maximum rated operating current of a circuit breaker can be used to ensure that the circuit breaker can operate safely and reliably in a battery cluster with a predetermined operating load. The rated current flowing through the circuit breaker can be greater than or equal to the maximum discharge current of the battery cell.

[0081] Based on this, according to the working characteristics of the circuit breaker mentioned above, the maximum rated operating current of the circuit breaker can be expressed as in formula (5).

[0082] (5);

[0083] Among them, I d_u This can be characterized by the maximum rated operating current of the fuse, k. n 'It can be represented as the first predetermined work segmentation coefficient, wherein the first predetermined work segmentation coefficient can be set to 1.25, without any specific limitation.

[0084] The maximum short-time withstand current of a circuit breaker can be characterized as its ability to withstand the thermal shock of short-circuit current within a predetermined period. The maximum short-time withstand current of a circuit breaker can be used to ensure that it can reliably interrupt short-circuit currents and withstand the maximum short-circuit current surge released by a battery cell under short-circuit fault conditions, thus preventing damage to the circuit breaker.

[0085] Based on this, according to the withstand characteristics of the circuit breaker, the maximum short-time withstand current of the circuit breaker can be expressed as formula (6).

[0086] (6);

[0087] Among them, I d_cs This can be characterized as the maximum short-time withstand current of the circuit breaker, k cs It can be represented as the second predetermined work break-off coefficient, wherein the second predetermined work break-off coefficient can be set to 1.1, without any specific limitation.

[0088] According to an embodiment of the present invention, the maximum rated breaking current of the nth circuit breaker is determined based on the minimum short-circuit current of the nth battery cell and the first predetermined breaking amplification factor.

[0089] The maximum rated breaking current of a circuit breaker can be characterized as the maximum short-circuit current that the circuit breaker can safely disconnect in a short period of time. In order to ensure that the circuit breaker can reliably interrupt external short-circuit fault currents outside the fuse's melting range, the maximum rated breaking current needs to be greater than the minimum short-circuit current that the fuse can disconnect.

[0090] Based on this, according to the breaking characteristics of the circuit breaker mentioned above, the maximum rated breaking current of the circuit breaker can be expressed as in formula (7).

[0091] (7);

[0092] Among them, I d_cu 'can be characterized as the maximum rated breaking current of the circuit breaker, k cu 'It can be represented as a first predetermined segmentation amplification factor, wherein the first predetermined segmentation amplification factor can be set to 1.1, without any specific limitation.

[0093] According to an embodiment of the present invention, the parameters of the nth initial circuit breaker are configured based on the maximum rated operating current, maximum short-time withstand current, maximum rated breaking current, and operating breaking current of the nth circuit breaker, thereby obtaining the configured nth circuit breaker.

[0094] The operating breaking current of the nth circuit breaker is determined based on the maximum discharge current of the nth battery cell.

[0095] The operating breaking current of a circuit breaker can be characterized as the current value that the circuit breaker can repeatedly interrupt. In energy storage power stations, circuit breakers can also serve as load interruption devices to enable the charging and discharging of different battery modules. Therefore, the operating breaking current of the circuit breaker can be set as the maximum discharge current of the battery cell.

[0096] Based on this, according to the operating characteristics of the circuit breaker, the operating breaking current of the circuit breaker can be expressed as in formula (8).

[0097] (8);

[0098] Among them, I d_nu It can be characterized as the operating breaking current of the circuit breaker.

[0099] The initial circuit breaker can be characterized as a circuit breaker that has not been configured with parameters. Based on the relevant circuit breaker parameters confirmed above, the initial circuit breaker is configured with parameters to obtain a configured circuit breaker.

[0100] According to an embodiment of the present invention, based on the ampere-second characteristics between the fuse and the circuit breaker, the operating characteristics and related operational characteristics of the circuit breaker, and according to the minimum short-circuit current that the battery cell can release, the maximum short-circuit current, and the maximum (permissible) discharge current of the battery cell, the circuit breaker is configured to provide comprehensive short-circuit fault protection for the battery cell using a circuit breaker with a fault current operating range different from that of the fuse.

[0101] According to an embodiment of the present invention, the maximum rated operating current and the maximum rated breaking current of the nth circuit breaker can also be configured in the following manner.

[0102] According to an embodiment of the present invention, the current configuration state of the nth battery module and the correction information corresponding to the nth circuit breaker electrically connected to the nth battery module are determined based on the historical fault information of the nth battery module and the historical maintenance information corresponding to the historical fault information.

[0103] The correction information includes at least one of aging correction information and circuit breaker correction information.

[0104] For the parameter configuration of the maximum rated operating current and maximum rated breaking current of the circuit breaker corresponding to the battery module, the health status of the battery cell and the usage status of the fuse can also be taken into consideration as parameter configuration factors.

[0105] The battery module's historical fault information can include information such as the short-circuit fault current and the actuators that disconnected the battery module during the previous fault. Historical maintenance information can include information on the replacement or reset of components corresponding to the previous fault. The current configuration status can include information on the replacement or reset of current components.

[0106] For example, the historical fault information of the battery module indicates that the action device that disconnects the battery module is a circuit breaker, and the corresponding historical maintenance information indicates that the circuit breaker was reset and neither the battery cell nor the fuse was replaced. Based on the historical fault information and historical maintenance information of the battery module, the current configuration status can be determined as circuit breaker reset and neither the battery cell nor the fuse was replaced.

[0107] When battery cells are aging, their internal resistance increases, causing the discharge current of aged cells to be lower than that of normal cells. However, aged cells are more prone to higher transient current spikes compared to normal cells. Similarly, for fuses that have been used for some time, although the internal resistance wire is not broken, if the battery cell's discharge current exceeds the minimum short-circuit current, the internal resistance wire will deform due to slow heating, resulting in a smaller cross-sectional area.

[0108] Therefore, by adjusting the coefficient used to determine the maximum rated operating current, the updated maximum rated operating current can include the transient current spikes caused by aging battery cells within the normal operating range (improving the current margin of the circuit breaker). At the same time, it can also prevent misjudgment of short circuit faults caused by the deformation of the resistance wire in the fuse, which can quickly blow even if the minimum short circuit current is not reached. (That is, when the fuse blows due to the discharge current of the battery cell caused by the deformation of the resistance wire, the battery management module can determine whether the fuse blows due to an external short circuit fault based on the configuration of the maximum rated operating current of the circuit breaker and the dynamic conduction virtual impedance. If it is not caused by an external short circuit fault, the blowing of the aging fuse will not affect the control timing between the circuit breaker and the fuse in the external short circuit fault. If it is caused by an external short circuit fault, the battery management module can also intervene to reduce the impact of the aging fuse on the control timing between the circuit breaker and the fuse.)

[0109] Therefore, by adjusting the coefficient used to determine the maximum rated breaking current, the updated maximum rated breaking current can provide a protection margin for the discharge current of the aging battery cell that may be concentrated near the original maximum rated breaking current range when an external short circuit fault occurs (the discharge current of the aging battery cell when an external short circuit fault occurs is usually less than that of the healthy battery cell when an external short circuit fault occurs). At the same time, it can also provide fallback protection for the fuse failure caused by the uneven deformation of the resistance wire in the fuse and the insufficient melting heat generated by the discharge current that may be concentrated near the original maximum rated breaking current range when an external short circuit fault occurs (that is, the aging resistance wire may not be a uniform cylinder, and when the discharge current of the battery cell is exactly near the original maximum rated breaking current range, the melting heat generated may be insufficient, resulting in a small gap in the resistance wire at the thinner part, but the arc still remains burning in the small gap, thus causing the physical structure to break, but the electrical connection of the circuit is not completely broken).

[0110] Based on this, the relevant adjustment and correction information during the configuration of the maximum rated operating current and maximum rated breaking current can be determined according to the device replacement information in the current configuration status. This allows for targeted, precise, and flexible configuration of the circuit breaker parameters in conjunction with the actual status of the battery module.

[0111] For example, if the current configuration state is determined to be that neither the battery cells nor the fuses have been replaced, the correction information corresponding to the nth circuit breaker electrically connected to the nth battery module can be determined to include aging correction information and fuse correction information. Similarly, if the current configuration state is determined to be that the battery cells have not been replaced, the correction information corresponding to the nth circuit breaker electrically connected to the nth battery module can be determined to include aging correction information. And if the current configuration state is determined to be that the fuses have not been replaced, the correction information corresponding to the nth circuit breaker electrically connected to the nth battery module can be determined to include fuse correction information.

[0112] According to an embodiment of the present invention, when the correction information includes aging correction information and fuse correction information, the first initial weight set corresponding to the operating current and the second initial weight set corresponding to the breaking current are respectively adjusted according to the battery aging degree of the nth battery cell and the usage degree of the nth fuse, so as to obtain the first target weight set corresponding to the operating current and the second target weight set corresponding to the breaking current.

[0113] The first initial weight set is determined based on the working weight allocation strategy, the second initial weight set is determined based on the segmentation weight allocation strategy, the first target weight set includes the first target aging correction weight and the first target loss correction weight, and the second target weight set includes the second target aging correction weight and the second target loss correction weight.

[0114] If the current configuration status is determined to be that neither the battery cell nor the fuse has been replaced, the correction information may include aging correction information and fuse correction information.

[0115] The aging degree of a battery cell can be determined based on the current real-time health measurement value and aging grading threshold of the battery. The usage degree of a fuse can be characterized by the consumption degree of the resistance wire inside the fuse, which can be determined based on the real-time cross-sectional area loss rate of the resistance wire and the loss grading threshold.

[0116] For example, the aging grading threshold indicates that 90% < health measurement value < 100% is mild battery aging, 80% < health measurement value < 90% is moderate battery aging, and 70% < health measurement value < 80% is severe battery aging. If the real-time health measurement value of the battery cell is 83%, it can be determined that the battery cell is in a moderate aging state.

[0117] For example, the loss grading threshold indicates that a fuse is lightly used if the resistance wire loss rate is less than 100%, a fuse is moderately used if the loss grading threshold is less than 90%, and a fuse is heavily used if the loss grading threshold is less than 70%. The real-time cross-sectional area loss rate of the fuse is 92%, which indicates that the fuse is in a lightly used state.

[0118] Specifically, regarding the real-time cross-sectional area loss rate of the resistance wire inside the fuse, the battery management module can monitor the discharge current flowing through each fuse in real time. When the monitored current flowing through the fuse is greater than the minimum short-circuit current, the heat value within the sampling period can be calculated based on the current value, the sampling period, and the rated resistance value of the resistance wire. Then, the heat values ​​of each sampling period are summed to obtain the total heat value related to the resistance wire melting. Based on the total heat value, the melting coefficient, and the rated resistance value of the resistance wire, the actual resistance value of the resistance wire inside the fuse is determined. Based on the actual resistance value, resistivity, and resistance wire length inside the fuse, the actual cross-sectional area of ​​the resistance wire inside the fuse at this time is deduced. Finally, the real-time cross-sectional area loss rate of the resistance wire is obtained by comparing the currently calculated actual cross-sectional area with the unused initial cross-sectional area.

[0119] The operating weight allocation strategy can be an initial weight allocation strategy related to the operating current, determined based on the relationship between operating current and battery aging and fuse usage. Similarly, the breaking weight allocation strategy can be an initial weight allocation strategy related to the breaking current, determined based on the relationship between breaking current and battery aging and fuse usage.

[0120] For example, the working weight allocation strategy can make the degree of fuse usage have a greater impact on the adjustment of the working current. Therefore, the first initial aging correction weight in the first initial weight set can be initially set to 0.3, and the first initial loss correction weight can be set to 0.7.

[0121] For example, the breaking weight allocation strategy can make the degree of battery aging have a greater impact on the adjustment of breaking current. Therefore, the first initial aging correction weight in the first initial weight set can be initially set to 0.6, and the first initial loss correction weight can be set to 0.4.

[0122] Given the current battery cell's aging level and fuse usage level, the first initial aging correction weight and the first initial loss correction weight within the first initial weight set, as well as the second initial aging correction weight and the second initial loss correction weight within the second initial weight set, can be adjusted based on the adjustment emphasis corresponding to the operating current and breaking current, to obtain the first target weight set and the second target weight set.

[0123] For example, the adjustment focus corresponding to the operating current and breaking current could be as follows: when the aging level of the battery cell and the usage level of the fuse are at the same level (e.g., both are at a light level), no initial weight adjustment is made; when the aging level of the battery cell and the usage level of the fuse are at different levels (e.g., the battery cell is at a light level of aging and the fuse is at a moderate level of aging), the initial weight is adjusted based on a predetermined weight adjustment step. The predetermined weight adjustment step can be set empirically and is not restricted.

[0124] At this point, the battery aging level of the nth battery cell is severely aged, with a real-time health measurement value of 73%. The usage level of the nth fuse is lightly used, with a measured cross-sectional area loss rate of 92%. The predetermined weight adjustment step corresponding to the operating current can be 0.1, and the predetermined weight adjustment step corresponding to the breaking current can be 0.05. Therefore, the first target aging correction weight can be 0.4, the first target loss correction weight can be 0.6, the second target aging correction weight can be 0.65, and the second target loss correction weight can be 0.35.

[0125] According to an embodiment of the present invention, the aging correction parameters of the nth battery cell are obtained based on the real-time health measurement value and the rated health threshold of the nth battery cell; and the loss correction parameters of the nth fuse are obtained based on the real-time resistance wire parameters and the rated resistance wire parameters of the nth fuse.

[0126] Based on the real-time health measurements and rated health thresholds of the battery cells, the health status difference of the battery cells can be calculated first. Then, the health status difference is adjusted using aging parameters determined by the degree of battery aging to obtain aging adjustment parameters. Finally, based on the aging adjustment parameters and predetermined aging parameters, the aging correction parameters of the battery cells are obtained. The aging degree parameters can be set based on experience and the specific conditions of the energy storage power station, and are not specifically limited thereto.

[0127] For example, the real-time health measurement value of the battery cell is 87, the rated health threshold is 100, the health status difference of the battery cell is 13, the aging degree parameter determined according to the battery aging degree is 0.002, the health status difference is adjusted using the aging degree parameter to obtain the aging adjustment parameter of 0.026, and then the aging correction parameter of the battery cell is obtained as 1.026 based on the aging adjustment parameter and the predetermined aging parameter.

[0128] The real-time resistance wire parameters of a fuse can include the current cross-sectional area of ​​the resistance wire. Based on the real-time resistance wire parameters and the rated resistance wire parameters, the difference in the cross-sectional area of ​​the fuse's resistance wires can be calculated first. Then, using a usage parameter determined according to the fuse's usage level, the ratio between the difference in the cross-sectional area of ​​the resistance wires and the rated cross-sectional area is adjusted to obtain the cross-sectional adjustment parameter. Finally, based on the cross-sectional adjustment parameter and the predetermined cross-sectional parameter, the fuse's loss correction parameter is obtained. The usage parameter can be set based on experience and the specific conditions of the energy storage power station, and is not specifically limited thereto.

[0129] For example, the real-time resistance wire parameter of the fuse is 0.015, the rated resistance wire parameter (rated resistance wire cross-sectional area) is 0.018, the resistance wire cross-sectional difference is 0.003, the ratio between the resistance wire cross-sectional difference and the rated resistance wire cross-sectional area is 0.17, the usage level parameter determined according to the usage level of the fuse is 0.4, the ratio between the resistance wire cross-sectional difference and the rated resistance wire cross-sectional area is adjusted using the usage level parameter to obtain the cross-sectional adjustment parameter of 0.068, and then the loss correction parameter of the fuse is obtained as 1.068 based on the cross-sectional adjustment parameter and the predetermined cross-sectional parameter.

[0130] According to an embodiment of the present invention, the aging correction parameter and the loss correction parameter are weighted and summed using a first target weight set to obtain the operating current correction parameter; the aging correction parameter and the loss correction parameter are weighted and summed using a second target weight set to obtain the breaking current correction parameter.

[0131] For example, if the first target aging correction weight is 0.4, the first target loss correction weight is 0.6, the battery cell aging correction parameter is 1.026, and the fuse loss correction parameter is 1.068, then the operating current correction parameter is 0.4104 + 0.6408 = 1.0512; the second target aging correction weight can be 0.65, and the second target loss correction weight can be 0.35, then the breaking current correction parameter is 0.6669 + 0.3738 = 1.0407.

[0132] According to an embodiment of the present invention, the predetermined operating breaking coefficient is adjusted using the operating current correction parameter to obtain the target operating breaking coefficient of the nth circuit breaker; the predetermined breaking amplification coefficient is adjusted using the breaking current correction parameter to obtain the target breaking amplification coefficient of the nth circuit breaker.

[0133] The predetermined breaking capacity factor can be characterized as the basic breaking capacity factor to be adjusted. For example, the predetermined breaking capacity factor can be set to 1.25, the operating current correction parameter is 1.0512, and the target breaking capacity factor is 1.31. The predetermined breaking capacity amplification factor can be characterized as the basic breaking capacity amplification factor to be adjusted. For example, the predetermined breaking capacity amplification factor can be set to 1.1, the breaking current correction parameter is 1.0407, and the target breaking capacity factor is 1.14.

[0134] The maximum adjustment value can be set for the target breaking capacity coefficient. For example, the maximum target breaking capacity coefficient can be 1.35. If the calculated value exceeds 1.35, 1.35 can be used for subsequent calculations of the maximum rated operating current. Similarly, the maximum adjustment value can be set for the target breaking capacity amplification factor. For example, the maximum target breaking capacity amplification factor can be 1.2. If the calculated value exceeds 1.2, 1.2 can be used for subsequent calculations of the maximum rated operating current.

[0135] According to an embodiment of the present invention, the maximum rated operating current of the nth circuit breaker is determined based on the maximum discharge current of the nth battery cell and the target operating breaking capacity; the maximum rated breaking current of the nth circuit breaker is determined based on the minimum short-circuit current of the nth battery cell and the target breaking capacity amplification factor.

[0136] Based on the target operating breaking coefficient and the maximum discharge current, the maximum rated operating current can be obtained by referring to the above formula (5); based on the minimum short-circuit current and the target breaking amplification coefficient, the maximum rated breaking current can be obtained by referring to the above formula (7).

[0137] The circuit breaker can be an intelligent circuit breaker with configurable and adjustable parameters. After the maximum rated operating current and the maximum rated breaking current are determined, the parameters of the circuit breaker can be adjusted.

[0138] According to an embodiment of the present invention, the aging state of the battery cell and the cross-sectional state of the resistance wire in the fuse can be used as adjustment factors for the parameter configuration of the maximum rated operating current and the maximum rated breaking current of the circuit breaker, so as to obtain circuit breaker parameters that are compatible with the currently aging battery and fuse.

[0139] Compared to healthy battery cells, aging battery cells are more prone to higher transient peak currents during normal discharge. Similarly, compared to unused fuses, the cross-sectional area of ​​the resistance wire in a used fuse changes due to the low-temperature heat generated during its use. Therefore, during maintenance, to adapt to aging battery cells and fuses that have been used for a long time, the operating breaking coefficient and breaking amplification coefficient corresponding to the operating current can be adjusted based on the degree of aging of the battery cells and the usage of the fuses. This yields circuit breaker parameters with maximum rated operating current and maximum rated breaking current that can be flexibly configured and better suited to the current battery environment. This allows for circuit breaker upgrades, improving circuit breaker reliability and anti-interference capabilities, as well as the operational stability of the energy storage power station.

[0140] Figure 4 A schematic diagram of the current cut-off range of a circuit breaker and a fuse according to an embodiment of the present invention is shown.

[0141] like Figure 4 As shown, for the full current range where an external short-circuit fault may occur in the battery cell, the circuit breaker tripping interval is set before the fuse tripping interval, and there is a partial overlap between the circuit breaker tripping interval and the fuse tripping interval to ensure reliable tripping of the external short-circuit fault. The maximum discharge current I of the battery cell is... b_n Less than the minimum short-circuit current I of the battery cell sc_min The minimum short-circuit current of the battery cell is less than the maximum short-circuit current I of the battery cell. sc_max Meanwhile, due to the possibility that the short-circuit resistance between multiple battery cells may be large during an external short-circuit fault, the discharge current during the fault may be less than the maximum discharge current I. b_n Therefore, the circuit breaker tripping range can include from 0A to I. b_nA, so as to facilitate the interruption of various short-circuit faults.

[0142] According to an embodiment of the present invention, any battery cluster may include N battery modules and N circuit breakers, and the battery management module may also be used to perform the following operations.

[0143] According to an embodiment of the present invention, for the nth battery module, the battery voltage change of the nth battery module is obtained based on the discharge voltage of the nth battery module at time t-1 and the discharge voltage at time t; the battery current change of the (n+1)th battery module is obtained based on the charging current of the (n-1)th battery module at time t and the charging current at time t.

[0144] In the event of an external short circuit fault between the (n-1)th and nth battery modules, the discharge voltage of the battery cluster including the (n-1)th and nth battery modules will decrease. This will lead to an abnormal situation where adjacent normal battery clusters will reverse charge the battery cluster with the short circuit fault, resulting in an increase in the charging current at the sampling point of the (n+1)th battery module that is electrically connected to the (n-1)th and nth battery modules.

[0145] The change in battery voltage of the nth battery module can be shown in formula (9), and the change in battery current of the nth battery module can be shown in formula (10).

[0146] (9);

[0147] Among them, △U n This can be represented as the change in battery voltage of the nth battery module, U n (t) can be represented as the discharge voltage of the battery module at time t, U n (t-1) can be represented as the discharge voltage of the battery module at time t-1.

[0148] (10);

[0149] Among them, △I n+1 This can be characterized as the change in battery current of the nth battery module, I. n+1 (t) can be represented as the charging current of the battery module at time t, I n+1 (t-1) can be represented as the charging current of the battery module at time t-1.

[0150] According to an embodiment of the present invention, the dynamic conduction virtual impedance of the nth battery module is obtained based on the battery voltage change of the nth battery module and the battery current change of the (n+1)th battery module.

[0151] The dynamic conduction virtual impedance of the nth battery module can be shown in formula (11).

[0152] (11);

[0153] Among them, R n It can be characterized as the dynamic conduction virtual impedance of the nth battery module.

[0154] According to an embodiment of the present invention, based on the short-circuit fault condition, the operating status of the nth battery module is determined according to the dynamic conduction virtual impedance of the nth battery module, and the operating status result of the nth battery module is obtained.

[0155] Based on the open-circuit voltage and internal resistance voltage drop of the battery cells in the battery module, the operating relationship between the voltage across the battery cells in the battery module and the current flowing through the battery cells in the battery module can be constructed. The operating relationship between the terminal voltage and the current can be shown in formula (12).

[0156] (12);

[0157] Where U can be represented as the terminal voltage of the battery cell within the battery module, I can be represented as the current flowing through the battery cell within the battery module, and R0 can be represented as the internal resistance of the battery cell within the battery module. ocv It can be characterized as open-circuit voltage, where IR0 can be characterized as the internal resistance voltage drop of the battery cell.

[0158] Based on the operating relationship between voltage and current (Formula (12)), the operating relationship between voltage difference and current difference at adjacent sampling times can be obtained according to the operating relationship of the battery cell at two adjacent sampling times. The operating relationship between voltage difference and current difference can be shown in Formula (13).

[0159] (13);

[0160] Here, ΔU can be represented as the difference in the terminal voltage of the battery cell at two adjacent sampling times, and ΔI can be represented as the difference in the current flowing through the battery cell at two adjacent sampling times.

[0161] According to the operating relationship between voltage difference and current difference (formula (13)), it can be seen that when the battery cell is in normal discharge state, the difference between the terminal voltage of the battery cell at two adjacent sampling times and the difference between the current flowing through the battery cell at two adjacent sampling times can both be greater than 0, that is, the internal resistance of the battery cell will also be greater than 0; similarly, when the battery cell is in normal charging state, the difference between the terminal voltage of the battery cell at two adjacent sampling times and the difference between the current flowing through the battery cell at two adjacent sampling times can both be less than 0, that is, the internal resistance of the battery cell will also be less than 0.

[0162] Conversely, when the battery cell is in an abnormal discharge or abnormal charging state (external short circuit fault), the difference between the terminal voltages of the battery cell at two adjacent sampling times can be greater than 0 or less than 0, while the difference between the currents flowing through the battery cell at two adjacent sampling times corresponding to the terminal voltage difference can be less than 0 or greater than 0. That is, the internal resistance of the battery cell may be less than 0. Thus, based on the operating relationship between the voltage difference and current difference under normal discharge, normal charging, abnormal discharge, and abnormal charging states, the short circuit fault conditions can be obtained.

[0163] Based on this, the operating status of the battery cells in the battery module can be obtained according to the short-circuit fault conditions and the dynamic conduction virtual impedance of the battery cells in the battery module.

[0164] According to an embodiment of the present invention, if the operating status result indicates that the dynamic conduction virtual impedance of the nth battery module is less than a first predetermined threshold, the nth battery module is confirmed to be a faulty battery module in a short-circuit fault state.

[0165] The first predetermined threshold can be 0, which is the threshold used to determine whether an external short-circuit fault has occurred in the short-circuit fault condition. When the dynamic conduction virtual impedance of the battery cell is less than 0, it can be confirmed that the battery cell in the battery module is in a short-circuit fault state.

[0166] According to an embodiment of the present invention, a target control signal is generated and sent to the nth circuit breaker based on the discharge current of the nth battery module at time t and the breaking current threshold of the nth circuit breaker, so as to disconnect the nth battery module in the short-circuit fault state from other battery modules.

[0167] If the nth battery module is determined to be in a short-circuit fault state, the system can determine whether the nth circuit breaker should disconnect and isolate the faulty battery module based on the circuit breaker current threshold corresponding to the nth battery module and the nth circuit breaker. If it is determined that the nth circuit breaker should disconnect and isolate the faulty battery module, the battery management module can generate a target control signal and send it to the nth circuit breaker.

[0168] According to an embodiment of the present invention, during the normal operation of the energy storage power station, the battery management module can monitor the operating status of each battery module in real time. Based on the discharge voltage of the battery cells within each battery module at time t-1 and time t, and the charging current potentially caused by an external short-circuit fault, the dynamic conduction virtual impedance of each battery module is calculated. Combining the short-circuit fault conditions determined based on the open-circuit voltage and internal resistance voltage drop of the battery module, an external short-circuit fault judgment is performed on the dynamic conduction virtual impedance of each battery module. If a battery module is determined to be in a short-circuit fault state, the responsibility for disconnection needs to be determined based on the discharge current of the faulty battery module at that time and the corresponding circuit breaker's breaking current threshold. Based on the judgment result, a corresponding target control signal is generated and sent to the circuit breaker to disconnect the battery module in the short-circuit fault state from the normal battery modules. It enables real-time monitoring of each battery module. By introducing the dynamic conduction virtual impedance of each battery module as the core criterion for judging whether an external short circuit fault has occurred, it is not affected by complex environments such as battery aging and state of charge. It avoids the inaccuracy of judging solely by the discharge current or discharge voltage of the battery module, and improves the high accuracy and high reliability of detecting external short circuit faults.

[0169] According to an embodiment of the present invention, the battery management module may also perform the following operations.

[0170] According to an embodiment of the present invention, when the breaking current threshold of the nth circuit breaker and the minimum short-circuit current of the nth battery cell are equal, the discharge current of the nth battery module at time t is controlled to cut off based on the minimum short-circuit current of the nth battery cell, and the control cut-off judgment result is obtained.

[0171] In one embodiment, the circuit breaking current threshold can be the minimum short-circuit current of the battery cell. When the circuit breaking current threshold is equal to the minimum short-circuit current of the battery cell, the discharge current of the nth battery module at time t can be controlled and cut off based on the minimum short-circuit current of the battery cell. The process of controlling the cut-off judgment can be as shown in formula (14).

[0172] (14);

[0173] Among them, I n (t) can be represented as the discharge current of the nth battery module at time t.

[0174] If the discharge current of the nth battery module at time t is less than the minimum short-circuit current of the battery cell, it can be confirmed that the circuit breaker is responsible for disconnecting and isolating the faulty battery module. If the discharge current of the nth battery module at time t is greater than or equal to the minimum short-circuit current of the battery cell, it can be confirmed that the fuse is responsible for disconnecting and isolating the faulty battery module.

[0175] According to an embodiment of the present invention, if the control cut-off judgment result indicates that the discharge current of the nth battery module at time t is greater than the minimum short-circuit current of the nth battery cell, a target control signal is generated and sent to the nth circuit breaker to cause the nth circuit breaker to open, thereby disconnecting the nth battery module from other battery modules.

[0176] If it is confirmed that the circuit breaker is responsible for disconnecting and isolating the faulty battery module, the battery management module can generate a target control signal and send it to the nth circuit breaker.

[0177] According to an embodiment of the present invention, if the control cut-off judgment result indicates that the discharge current of the nth battery module at time t is less than or equal to the minimum short-circuit current of the nth battery cell, the nth fuse blows, thereby disconnecting the nth battery module from other battery modules.

[0178] According to an embodiment of the present invention, when the circuit breaking current threshold is equal to the minimum short-circuit current of the battery cell, the minimum short-circuit current of the battery cell can be directly used as the core criterion for determining the disconnection responsibility of the battery cell in a fault short-circuit state. This clarifies whether the battery cell currently in a fault short-circuit state should be disconnected and isolated by its corresponding circuit breaker or by its corresponding fuse, avoiding simultaneous disconnection and melting of the circuit breaker and fuse, which would lead to chaotic operation sequence, increased fault operation costs, and improved operational reliability, robustness, and risk resistance of the energy storage power station.

[0179] According to an embodiment of the present invention, the battery management module may also perform the following operations.

[0180] According to an embodiment of the present invention, the fuse control coefficient is determined based on the real-time resistance wire parameters and the rated resistance wire parameters of the nth fuse in the nth battery module.

[0181] Furthermore, considering the usage of the internal resistance wire of the fuse, the circuit breaking current threshold used as the core judgment criterion can be comprehensively adjusted in conjunction with the current usage of the fuse, so as to more targeted and timely determine the responsible device for the current fault isolation.

[0182] If an external short circuit fault occurs in the nth battery module and the current configuration state is that the fuse has not been replaced, the current real-time resistance wire parameter of the fuse can be obtained by referring to the calculation method of the actual resistance value of the resistance wire in the fuse or other general calculation methods, that is, the current actual resistance value.

[0183] After obtaining the actual resistance value of the resistance wire inside the fuse, the current resistance loss rate can be calculated based on the actual resistance value and the rated resistance value of the resistance wire inside the fuse. Then, based on the current resistance loss rate and an empirical coefficient, the fuse control coefficient used to adjust the minimum short-circuit current is calculated.

[0184] Among them, the empirical coefficient can be preset based on experience or determined by fitting multiple historical data.

[0185] For battery cells, fuses, and circuit breakers within the same battery cluster, their parameters, models, and operating environments are generally considered to be similar. Therefore, fusing analysis curves can be constructed based on the fusing performance of fuses within the same battery cluster. To improve accuracy, multiple battery modules within the same battery cluster can be divided into regions to further enhance the similarity of their parameters, models, and operating environments.

[0186] The fusing analysis curve can be constructed based on the historical fusing current values ​​of multiple historical fuses at the time of fusing (i.e., the historical discharge current of the battery cell corresponding to the fuse) and multiple calculated historical resistance loss rates corresponding to the fuses. However, considering that the historical fusing current value at the time of fusing may be greater than or equal to the true minimum fusing current of the aging fuse, directly using the historical fusing current value at the time of fusing may lead to deviations in the fusing analysis curve. Therefore, based on the historical resistance loss rates of multiple historical fuses at the time of fusing, intervals can be defined for multiple historical fuses. Then, the fusing analysis curve is constructed based on the minimum historical fusing current value within each interval and the average historical resistance loss rate of that interval.

[0187] For example, the first historical resistor loss rate is 4.0, and the first historical fuse current value is 200A; the second historical resistor loss rate is 5.0, and the second historical fuse current value is 180A; the third historical resistor loss rate is 6.0, and the third historical fuse current value is 220A; the fourth historical resistor loss rate is 11.0, and the fourth historical fuse current value is 150A; the fifth historical resistor loss rate is 12.0, and the fifth historical fuse current value is 160A; the sixth historical resistor loss rate is 13.0, and the sixth historical fuse current value is 170A; the seventh historical resistor loss rate is 20.0, and the seventh historical fuse current value is 130A; the eighth historical resistor loss rate is 21.0, and the eighth historical fuse current value is 109A; the ninth historical resistor loss rate is 22.0, and the ninth historical fuse current value is 87A.

[0188] The first historical resistance loss rate to the third historical resistance loss rate are divided into the first interval, and the average value of the first historical resistance loss rate is 5.0. The fourth historical resistance loss rate to the sixth historical resistance loss rate are divided into the second interval, and the average value of the second historical resistance loss rate is 12.0. The seventh historical resistance loss rate to the ninth historical resistance loss rate are divided into the third interval, and the average value of the third historical resistance loss rate is 21.0.

[0189] Then, based on the second historical fusing current value of 180A and the average value of the first historical resistance loss rate of 5.0, the fourth historical fusing current value of 150A and the average value of the second historical resistance loss rate of 12.0, and the ninth historical fusing current value of 87A and the average value of the third historical resistance loss rate of 21.0, a fusing analysis curve is constructed.

[0190] Once the fuse analysis curve is constructed, it can be fitted using methods such as least squares to obtain empirical coefficients. Furthermore, considering that the discharge current of the faulty battery module can far exceed the true minimum fusing current of the aging fuse during an external circuit fault, a certain safety margin for the fault current can be introduced to adjust the minimum short-circuit current after parameter tuning.

[0191] According to an embodiment of the present invention, the minimum short-circuit current of the nth battery cell is adjusted using the fuse control coefficient to obtain the breaking current threshold of the nth circuit breaker.

[0192] Using the minimum short-circuit current of the battery cell as the basis for adjustment, the circuit breaker's breaking current threshold can be obtained by multiplying the fuse control coefficient and the minimum short-circuit current.

[0193] According to an embodiment of the present invention, based on the circuit breaker current threshold of the nth battery cell, the discharge current of the nth battery module at time t is controlled to cut off, and the control cut-off judgment result is obtained.

[0194] According to an embodiment of the present invention, if the control cut-off judgment result indicates that the discharge current of the nth battery module at time t is greater than the circuit breaker current threshold of the nth battery cell, a target control signal is generated and sent to the nth circuit breaker to cause the nth circuit breaker to open and disconnect the nth battery module from other battery modules.

[0195] If the discharge current of the nth battery module at time t is less than the calculated breaking current threshold, it can be confirmed that the circuit breaker is responsible for disconnecting and isolating the faulty battery module. If the discharge current of the nth battery module at time t is greater than or equal to the calculated breaking current threshold, it can be confirmed that the fuse is responsible for disconnecting and isolating the faulty battery module.

[0196] According to an embodiment of the present invention, by combining the aging state of the resistance wire in the fuse, the minimum short-circuit current is adaptively adjusted to obtain a more targeted circuit breaking current threshold corresponding to the battery module. Then, based on the circuit breaking current threshold and the discharge current of the battery module in a short-circuit fault state, the responsibility for fault disconnection is determined, thereby more accurately determining whether the current isolation should be achieved by the corresponding circuit breaker or by the corresponding fuse, thus improving the operational reliability, robustness, and risk resistance of the energy storage power station.

[0197] Furthermore, the battery management module can also monitor the status of fuses and circuits in real time. For open-circuit fault thresholds, time monitoring can be introduced. If it is determined that the faulty battery module has been isolated by a blown fuse and a fault current still exists in the circuit after a predetermined safe period, a target control signal is generated and sent to the corresponding circuit breaker to enable rapid backup isolation of the faulty battery module using the circuit breaker.

[0198] Furthermore, for aging battery cells, due to their increased internal resistance, when an external short circuit fault occurs, the discharge current of the faulty aging battery cell may be concentrated near the adjusted circuit breaker current threshold and the current fluctuation may be large. Therefore, a relevant fault current buffer zone can be set. When the discharge current of the faulty aging battery cell is within the fault current buffer zone due to fluctuation, the battery management module can maintain the previous control decision to avoid the control timing disorder between the fuse and the circuit breaker.

[0199] For example, the circuit breaker current threshold is 785A, the fault current buffer width can be 10A, and the discharge current of the faulty aging battery cell is concentrated between 780A and 790A. Therefore, the fault current buffer range can be 775A to 785A. Then, it is set that when the discharge current is greater than 785A, the fuse will blow to isolate the faulty battery module; when the discharge current is less than 785A, the circuit breaker will trip to isolate the faulty battery module. If the discharge current in the previous second is 790A, and the discharge current in the next second reaches 778A due to fluctuations, the battery management module can maintain the judgment that the fuse corresponding to the discharge current in the previous second has blown. If the discharge current in the next second reaches 770A due to fluctuations, the battery management module can determine that the circuit breaker should trip.

[0200] Figure 5 A flowchart of an external short-circuit fault isolation method for an electrochemical energy storage power station according to an embodiment of the present invention is shown.

[0201] like Figure 5 As shown, the external short-circuit fault isolation method of the electrochemical energy storage power station in this embodiment includes operations S510 to S530.

[0202] In operation S510, for any battery cluster, the dynamic on-state virtual impedance of multiple battery modules is determined based on the discharge current and discharge voltage of multiple battery modules.

[0203] In operation S520, based on multiple dynamic on-state virtual impedances and short-circuit fault conditions determined by the open-circuit voltage and internal resistance voltage drop of the battery module, the faulty battery module in a short-circuit fault state is identified from multiple battery modules.

[0204] In operation S530, a target control signal is generated and sent to the target circuit breaker based on the discharge current of the faulty battery module and the circuit breaking current threshold of the target circuit breaker corresponding to the target faulty battery module, so as to switch the connection state between multiple battery modules and isolate the faulty battery module in the short-circuit fault state from other battery modules in the normal state.

[0205] According to embodiments of the present invention, the performance of the external short-circuit fault isolation method for electrochemical energy storage power stations can be referenced to the performance of the external short-circuit fault isolation system for electrochemical energy storage power stations.

[0206] According to an embodiment of the present invention, any battery cluster includes N battery modules and N circuit breakers.

[0207] Figure 6 A flowchart of a method for generating a target control signal according to an embodiment of the present invention is shown.

[0208] like Figure 6As shown, the method for generating the target control signal in this embodiment includes operations S610 to S650.

[0209] In operation S610, the change in battery voltage of the nth battery module is obtained based on the discharge voltage of the nth battery module at time t-1 and the discharge voltage at time t; the change in battery current of the (n+1)th battery module is obtained based on the discharge current of the (n-1)th battery module at time t and the discharge current at time t.

[0210] In operation S620, the dynamic conduction virtual impedance of the nth battery module is obtained based on the change in battery voltage of the nth battery module and the change in battery current of the (n+1)th battery module.

[0211] In operation S630, based on the short-circuit fault condition and the dynamic conduction virtual impedance of the nth battery module, the operating status of the nth battery module is judged to obtain the operating status result of the nth battery module.

[0212] In operation S640, if the operating status result indicates that the dynamic conduction virtual impedance of the nth battery module is less than a first predetermined threshold, the nth battery module is confirmed to be a faulty battery module in a short-circuit fault state.

[0213] In operation S650, a target control signal is generated and sent to the nth circuit breaker based on the discharge current of the nth battery module at time t and the breaking current threshold of the nth circuit breaker.

[0214] Those skilled in the art will understand that the features described in the various embodiments of the present invention can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, the features described in the various embodiments of the present invention can be combined and / or combined in various ways without departing from the spirit and teachings of the present invention. All such combinations and / or combinations fall within the scope of the present invention.

Claims

1. An external short-circuit fault isolation system for an electrochemical energy storage power station, characterized in that, The system includes: A converter is used to convert initial power supply into target power supply. Multiple battery clusters are electrically connected to the converter. Each battery cluster includes multiple battery modules and multiple circuit breakers, which are alternately electrically connected. The multiple battery modules of the multiple battery clusters are used to provide initial power to the converter. The battery management module, electrically connected to the plurality of battery clusters, is used for any battery cluster comprising P battery modules and P circuit breakers: for the p-th battery module, the battery voltage change of the p-th battery module is obtained by subtracting the discharge voltage at time t-1 from the discharge voltage at time t; the battery current change of the (p+1)-th battery module is obtained by subtracting the charging current at time t-1 from the charging current at time t; the dynamic on-state virtual impedance of the p-th battery module is obtained by dividing the battery voltage change of the p-th battery module by the battery current change of the (p+1)-th battery module; and the dynamic on-state virtual impedance of the p-th battery module is determined based on the open-circuit voltage and internal resistance voltage drop of the battery module. Given a short-circuit fault condition, the operating status of the p-th battery module is determined based on its dynamic conduction virtual impedance, resulting in an operating status result for the p-th battery module. If the operating status result indicates that the dynamic conduction virtual impedance of the p-th battery module is less than zero, the p-th battery module is confirmed as a faulty battery module in a short-circuit fault state. Based on the discharge current of the faulty battery module and the breaking current threshold of the target circuit breaker corresponding to the target faulty battery module, a target control signal is generated and sent to the target circuit breaker to switch the connection status between multiple battery modules, isolating the faulty battery module in a short-circuit fault state from other battery modules in a normal state, where P-1≥p≥1.

2. The external short-circuit fault isolation system according to claim 1, characterized in that, The i-th battery module includes: The i-th battery cell has its first terminal electrically connected to the second terminal of the (i-1)-th circuit breaker that is electrically connected to the (i-1)-th battery module, and its second terminal electrically connected to the first terminal of the i-th fuse. The i-th battery cell is used to provide initial power to the converter, where P≥i≥2. The i-th fuse, the second end of the i-th fuse is electrically connected to the first end of the i-th circuit breaker which is electrically connected to the i-th battery module, is used to cut off the connection between the i-th battery cell and the other P-1 battery cells when the discharge current of the i-th battery cell is greater than the minimum rated fusing current, so that the i-th battery cell in the short-circuit fault state is isolated. In this configuration, the first end of the first battery cell in any battery cluster is electrically connected to the first end of the first battery cell in other battery clusters; the second end of the P-th fuse in any battery cluster is electrically connected to the inverter; the first end of the first fuse is electrically connected to the second end of the first battery cell; and the second end of the first fuse is electrically connected to the first end of the first circuit breaker that is electrically connected to the first battery module.

3. The external short-circuit fault isolation system according to claim 2, characterized in that, The nth fuse is configured as follows, where P ≥ n ≥ 1: Based on the ampere-second characteristics and the tripping time of the nth circuit breaker, the minimum short-circuit current of the nth battery cell is determined according to the rated discharge cut-off voltage and rated discharge cut-off resistance of the nth battery cell. The minimum short-circuit current of the nth battery cell is then determined as the minimum rated fusing current of the nth fuse. The rated discharge cut-off voltage represents the voltage when the battery cell is in its rated healthy state and its state of charge is at its minimum value. The rated discharge cut-off resistance represents the internal resistance of the battery cell at the rated discharge cut-off voltage. The maximum short-circuit current of the nth battery cell is determined based on the rated charging cut-off voltage and rated charging cut-off resistance of the nth battery cell; wherein, the rated charging cut-off voltage represents the voltage when the battery cell is in its rated healthy state and the state of charge value is at its maximum, and the rated charging cut-off resistance represents the internal resistance of the battery cell at the rated charging cut-off voltage. The maximum rated operating current of the nth fuse is determined based on the maximum discharge current of the nth battery cell and the predetermined fusing factor; the maximum rated fusing current of the nth fuse is determined based on the maximum short-circuit current of the nth battery cell and the predetermined fusing amplification factor. Based on the minimum rated fusing current, maximum rated operating current, and maximum rated fusing current of the nth fuse, the parameters of the nth initial fuse are configured to obtain the configured nth fuse.

4. The external short-circuit fault isolation system according to claim 3, characterized in that, The nth circuit breaker is configured as follows: The maximum rated operating current of the nth circuit breaker is determined based on the maximum discharge current of the nth battery cell and the first predetermined breaking capacity; the maximum short-time withstand current of the nth circuit breaker is determined based on the maximum short-circuit current of the nth battery cell and the second predetermined breaking capacity. The maximum rated breaking current of the nth circuit breaker is determined based on the minimum short-circuit current of the nth battery cell and the first predetermined breaking amplification factor. Based on the maximum rated operating current, maximum short-time withstand current, maximum rated breaking current, and operating breaking current of the nth circuit breaker, the parameters of the nth initial circuit breaker are configured to obtain the configured nth circuit breaker. The operating breaking current of the nth circuit breaker is determined based on the maximum discharge current of the nth battery cell.

5. The external short-circuit fault isolation system according to claim 3, characterized in that, The maximum rated operating current and maximum rated breaking current of the nth circuit breaker are also configured as follows: Based on the historical fault information of the nth battery module and the historical maintenance information corresponding to the historical fault information, determine the current configuration status of the nth battery module and the correction information corresponding to the nth circuit breaker electrically connected to the nth battery module. The correction information includes at least one of aging correction information and fuse correction information. When the correction information includes aging correction information and fuse correction information, the weights of the first initial weight set corresponding to the operating current and the second initial weight set corresponding to the breaking current are adjusted according to the battery aging degree of the nth battery cell and the usage degree of the nth fuse, respectively, to obtain the first target weight set corresponding to the operating current and the second target weight set corresponding to the breaking current. The first initial weight set is determined based on the operating weight allocation strategy, and the second initial weight set is determined based on the breaking weight allocation strategy. The first target weight set includes the first target aging correction weight and the first target loss correction weight, and the second target weight set includes the second target aging correction weight and the second target loss correction weight. Based on the real-time health measurement value and rated health threshold of the nth battery cell, the aging correction parameters of the nth battery cell are obtained; based on the real-time resistance wire parameters and rated resistance wire parameters of the nth fuse, the loss correction parameters of the nth fuse are obtained. The aging correction parameters and loss correction parameters are weighted and summed using the first objective weight set to obtain the operating current correction parameters; the aging correction parameters and loss correction parameters are weighted and summed using the second objective weight set to obtain the breaking current correction parameters. The target breaking coefficient of the nth circuit breaker is obtained by adjusting the predetermined breaking coefficient using the operating current correction parameter; the target breaking amplification coefficient of the nth circuit breaker is obtained by adjusting the predetermined breaking amplification coefficient using the breaking current correction parameter. The maximum rated operating current of the nth circuit breaker is determined based on the maximum discharge current of the nth battery cell and the target breaking capacity; the maximum rated breaking current of the nth circuit breaker is determined based on the minimum short-circuit current of the nth battery cell and the target breaking capacity amplification factor.

6. The external short-circuit fault isolation system according to claim 2, characterized in that, The battery management module is also used for: When the breaking current threshold of the nth circuit breaker is equal to the minimum short-circuit current of the nth battery cell, the discharge current of the nth battery module at time t is controlled to cut off based on the minimum short-circuit current of the nth battery cell, and the control cut-off judgment result is obtained, where P≥n≥1; If the control cut-off judgment result indicates that the discharge current of the nth battery module at time t is less than the minimum short-circuit current of the nth battery cell, a target control signal is generated and sent to the nth circuit breaker to make the nth circuit breaker open and disconnect the nth battery module from other battery modules. If the control cut-off judgment result indicates that the discharge current of the nth battery module at time t is greater than or equal to the minimum short-circuit current of the nth battery cell, the nth fuse will blow to disconnect the nth battery module from other battery modules.

7. The external short-circuit fault isolation system according to claim 2, characterized in that, The battery management module is also used for: The fuse control coefficient is determined based on the real-time resistance wire parameters and rated resistance wire parameters of the nth fuse in the nth battery module, where P≥n≥1; The minimum short-circuit current of the nth battery cell is adjusted using the fuse control coefficient to obtain the breaking current threshold of the nth circuit breaker. Based on the circuit breaker current threshold of the nth battery cell, the discharge current of the nth battery module at time t is controlled to cut off, and the control cut-off judgment result is obtained. If the control cut-off judgment result indicates that the discharge current of the nth battery module at time t is less than the circuit breaker current threshold of the nth battery cell, a target control signal is generated and sent to the nth circuit breaker to make the nth circuit breaker open and disconnect the nth battery module from other battery modules.

8. A method for isolating external short-circuit faults in an electrochemical energy storage power station, applied to an external short-circuit fault isolation system of an electrochemical energy storage power station as described in any one of claims 1-7, characterized in that, The method includes: For any given battery cluster, the dynamic on-state virtual impedance of multiple battery modules is determined based on the discharge current and discharge voltage of multiple battery modules. Based on multiple dynamic on-state virtual impedances and short-circuit fault conditions determined by the open-circuit voltage and internal resistance voltage drop of the battery module, the faulty battery module in a short-circuit fault state is identified from multiple battery modules. Based on the discharge current of the faulty battery module and the circuit breaking current threshold of the target circuit breaker corresponding to the target faulty battery module, a target control signal is generated and sent to the target circuit breaker to switch the connection state between multiple battery modules, so that the faulty battery module in the short-circuit fault state is isolated from other battery modules in the normal state.

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