A method and apparatus for detecting a flow battery module

Abstract

The application relates to the technical field of energy storage battery detection, in particular to a detection method and a detection device for a flow battery module. The battery module comprises a first shell, at least one battery stack arranged in the first shell, and a voltage detection interface arranged on the first shell. Each battery stack comprises a plurality of battery monomers. The voltage detection interface comprises parallel voltage sampling channels corresponding to the potential nodes of the battery monomers in the battery module. The detection method comprises the following steps: under the condition that the battery module meets a preset detection condition, collecting stack voltages of the battery stacks and monomer voltages of the battery monomers through the parallel voltage sampling channels; performing detection verification according to the stack voltages and the monomer voltages, and after the verification is passed, performing battery monomer fault detection according to the monomer voltages to obtain a fault detection result. In this way, the faulty battery monomers in the flow battery module can be quickly and accurately located.

Description

Technical Field

[0001] This application relates to the field of energy storage battery testing technology, and in particular to a testing method and a testing device for a flow battery module. Background Technology

[0002] During the factory testing, on-site maintenance, and troubleshooting of flow battery modules, the general method is to connect the main positive and negative terminals of the module or the battery stack leads out from the module to charge and discharge test equipment to conduct overall charge and discharge tests and obtain the test results of various indicators at the overall level. However, this method cannot determine which individual battery cell the fault in the test results originates from.

[0003] Currently, testing individual cells in flow battery modules requires disassembling the module casing or opening the battery stack connection structure to separate the internal cells before inspecting them one by one. Because the disassembly and reassembly process of the module or battery stack is complex, it may lead to risks such as sealing failure, poor electrical connection, and assembly errors. Therefore, some existing technologies have set potential leads for each individual cell inside the battery stack. Testers use testing equipment to measure each potential lead individually to record the open-circuit voltage or operating voltage of each cell. However, because it requires repeatedly moving the probes, checking the numbers, and manual recording, the measurement time increases linearly with the number of cells, and problems such as incorrect connections or missed measurements are prone to occur. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, this application provides a detection method and detection device for flow battery modules, which solves the technical problem that the existing detection methods are unable to quickly and accurately locate faulty battery cells in flow battery modules.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the main technical solutions adopted in this application include:

[0008] In a first aspect, embodiments of this application provide a detection method for a flow battery module. The battery module includes a first housing, at least one battery stack disposed within the first housing, and a voltage detection interface disposed on the first housing. Each battery stack includes multiple individual battery cells. The voltage detection interface includes parallel voltage sampling channels that correspond one-to-one with the potential nodes of each individual battery cell in the battery module. The method includes: when the battery module meets preset detection conditions, acquiring the stack voltage of each battery stack and the individual cell voltage of each individual battery cell through the parallel voltage sampling channels; performing detection and verification based on the stack voltage and the individual cell voltage; and after passing the verification, performing individual battery cell fault detection based on the individual cell voltage to obtain a fault detection result. The fault detection result includes a faulty individual battery cell, the faulty individual cell number of the faulty individual battery cell, and the faulty stack number of the battery stack in which the faulty individual battery cell is located.

[0009] In some embodiments of this application, the detection and verification based on the stack voltage and the individual cell voltage includes: determining whether the parallel sampling channel and the individual cell voltage corresponding to each battery stack are complete based on a first deviation between the stack voltage of each battery stack and the sum of the individual cell voltages of the individual cells in each battery stack.

[0010] In some embodiments of this application, the preset detection conditions include the battery module being in a static state, and the step of obtaining a fault detection result by detecting battery cell faults based on the voltage of each individual cell includes: obtaining the average value of the individual cell voltages of the individual cells in each battery stack at a first moment; when the second deviation between the individual cell voltage of the individual cell and the average value of the individual cell voltages of the corresponding battery stack exceeds a first preset threshold, determining the individual cell as the faulty individual cell, and determining the faulty individual cell number and the faulty stack number based on a preset mapping relationship.

[0011] In some embodiments of this application, the preset detection conditions include the battery module being in a static state. The step of obtaining a fault detection result by detecting battery cell faults based on the voltage of each individual cell includes: obtaining a third deviation between the individual cell voltage at a first moment and the individual cell voltage at a second moment in each battery stack, and obtaining the average value of the third deviation; when a fourth deviation between the third deviation and the average value of the third deviation exceeds a second preset threshold, determining the battery cell corresponding to the third deviation as the faulty battery cell, and determining the faulty cell number and the faulty stack number based on a preset mapping relationship.

[0012] In some embodiments of this application, the battery module further includes a current detection interface and a main detection interface disposed on the first housing. The current detection interface includes a current sampling channel connected to a current sensor inside the battery module. The preset detection conditions include controlling the battery module to be in a charging and discharging state through the main detection interface. The method further includes: acquiring the stack charging and discharging current of each battery stack and / or the total charging and discharging current of the battery module through the current sampling channel, and acquiring the total voltage of the battery module through the main detection interface; and performing battery cell fault detection based on the stack charging and discharging current and / or the total charging and discharging current, the total voltage, and the individual cell voltage of each battery cell to obtain the fault detection result.

[0013] In some embodiments of this application, the step of performing battery cell fault detection based on the stack charge-discharge current and / or the total charge-discharge current, the total voltage, and the individual cell voltage of each battery cell to obtain the fault detection result includes: calculating the efficiency of the battery module based on the stack charge-discharge current and / or the total charge-discharge current and the total voltage; and performing battery cell fault detection based on the efficiency and the individual cell voltage of each battery cell to obtain the fault detection result.

[0014] In some embodiments of this application, the efficiency includes at least one of coulombic efficiency, energy efficiency, and voltage efficiency.

[0015] In some embodiments of this application, the method further includes: acquiring the total charging and discharging current of the battery module through the main detection interface.

[0016] In some embodiments of this application, the parallel voltage sampling channel is connected to a voltage sampling resistor, the impedance of which is greater than the internal resistance of the corresponding battery cell.

[0017] Secondly, embodiments of this application provide a detection device for a flow battery module. The battery module includes a first housing, at least one battery stack disposed within the first housing, and a main detection interface, a voltage detection interface, and a current detection interface disposed on the first housing. Each battery stack includes multiple battery cells. The voltage detection interface includes parallel voltage sampling channels corresponding one-to-one with the potential nodes of each battery cell in the battery module. The current detection interface includes a current sampling channel connected to a current sensor inside the battery module. The device includes: a second housing; an adapter interface disposed on the second housing and adapted to the main detection interface, the voltage detection interface, and the current detection interface respectively; and a controller disposed within the second housing, the controller being connected to the adapter interface, and the controller being used to execute the detection method for the flow battery module described in the above embodiments.

[0018] (III) Beneficial Effects

[0019] The detection method and device for flow battery modules provided in this application embodiment, by setting a voltage detection interface on the housing of the flow battery module, and by using parallel voltage sampling channels in the voltage detection interface that correspond one-to-one with the potential nodes of each battery cell in the battery module, collects and verifies the stack voltage of each battery stack and the individual cell voltage of each battery cell, and after the verification is passed, performs battery cell fault detection based on the individual cell voltage to obtain the fault detection result, thereby realizing the rapid and accurate location of faulty battery cells in the flow battery module, effectively improving detection efficiency and positioning accuracy. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a flow battery module provided in some embodiments of this application;

[0021] Figure 2 A schematic flowchart illustrating the detection method for a flow battery module provided in some embodiments of this application;

[0022] Figure 3 This is a schematic diagram of the structure of a detection device for a flow battery module provided in some embodiments of this application. Detailed Implementation

[0023] To better understand the above technical solutions, exemplary embodiments of this application will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this application can be understood more clearly and thoroughly, and that the scope of this application can be fully conveyed to those skilled in the art.

[0024] Figure 1 The diagram below shows the structure of a flow battery module provided in some embodiments of this application. The flow battery module can be an all-vanadium redox flow battery module, etc., and there is no specific limitation here.

[0025] like Figure 1 As shown, the flow battery module, or battery module M1 for short, includes a first housing 10, at least one battery stack ST1 disposed within the first housing 10, and a voltage detection interface P21 disposed on the first housing 10. Each battery stack includes multiple battery cells, such as CELL1-CELL4. The voltage detection interface P21 includes parallel voltage sampling channels P2-V that correspond one-to-one with the potential nodes of each battery cell in the battery module M1, such as N0-N4.

[0026] For example, each battery cell is connected in series, and each battery cell has a potential node at both ends. Potential node N0 is the negative terminal of battery stack ST1, potential node N4 is the positive terminal of battery stack ST1, and N1-N3 are the potential nodes between every two battery cells CELL1-CELL4. The parallel voltage sampling channel P2-V connects each potential node N0-N4 to the corresponding pin of the voltage detection interface P21 via independent sampling cables, thereby concentrating the potential signals from each potential node inside battery stack ST1 and leading them to the outside of the first housing 10. During testing, the potential signals of multiple potential nodes in battery module M1 can be simultaneously acquired with a single connection, significantly simplifying the testing operation, shortening the testing time, and effectively reducing problems such as misconnections or missed tests that may occur due to repeated probe movements and individual number verification.

[0027] Figure 2 This is a schematic flowchart illustrating the detection method for a flow battery module provided in some embodiments of this application. For example... Figure 2 As shown, the testing method for this flow battery module includes the following steps:

[0028] S100. When the battery module meets the preset detection conditions, the stack voltage of each battery stack and the individual voltage of each battery cell are collected through the parallel voltage sampling channel P2-V.

[0029] During voltage detection, the detection port of the external detection equipment is connected to the voltage detection interface P21. The detection equipment can then synchronously acquire the potential signals of each potential node N0-N4 through the parallel voltage sampling channel P2-V. Based on the potential signals of potential nodes N0-N4, the stack voltage of battery stack ST1 and the individual voltage of each battery cell can be calculated. Since the battery cells are connected in series, the potential difference between any two adjacent potential nodes is the individual voltage of the corresponding battery cell. For example, the voltage of CELL1 is V1 = V N1 -V N0 The voltage of cell2 is V2 = V N2 -V N1 The voltage of cell 3 is V3 = V N3 -V N2 The voltage of cell 4 is V4 = V. N4 -V N3 The stack voltage V of battery stack ST1 ST1 V is calculated using the potential difference between potential nodes N4 and N0. ST1 =V N4 -V N0 .

[0030] S200. Detect and verify the voltage of each stack and each individual cell. After the verification is passed, perform individual cell fault detection based on the individual cell voltage to obtain the fault detection result. The fault detection result includes the faulty individual cell, the faulty individual cell number, and the faulty stack number of the battery stack in which the faulty individual cell is located.

[0031] For example, S200 includes two phases: a verification phase and a fault detection phase.

[0032] In some embodiments of this application, detection and verification are performed based on the voltage of each stack and the voltage of each individual cell, including: S210, determining whether the parallel sampling channel and individual cell voltage corresponding to each battery stack are complete based on the first deviation between the stack voltage of each battery stack and the sum of the individual cell voltages of the individual cells in each battery stack.

[0033] During the verification phase, the verification relationship formula ΣV is used. i ≈V stack For the voltage of each stack and the voltage of each individual cell V i The test and verification are performed, where i represents the i-th cell in the battery stack being verified, and V stack This indicates the stack voltage of the battery pack. For example, using... Figure 1 For example, the individual cell voltages of CELL1-CELL4 in battery stack ST1 are V1, V2, V3, and V4, respectively. The total voltage ΣV of each cell is obtained by summing the individual cell voltages of CELL1-CELL4. i At this time ΣV i =V1+V2+V3+V4, the stack voltage V of battery stack ST1 ST1 As V stack The values ​​are then compared using the above verification formula to verify the connection, numbering, and data integrity of the sampling points. Theoretically, the sum of the differences between adjacent potential nodes within the same battery stack is ΣV. i It should be equal to the value V, which is the difference between the two outermost nodes. ST1 Therefore, when the first deviation between the two is Δ1=V ST1 -ΣV i If the data is within the preset range, it indicates that the parallel sampling channels are connected normally, the individual voltage data is complete, and the numbering mapping is correct. If the verification is successful, the fault detection stage will begin.

[0034] If the first deviation Δ1 exceeds the preset threshold, it can be determined that there is a sampling abnormality in the series path of the battery cells within the battery stack, indicating that the verification has failed and the detection process is terminated. Specifically, when the first deviation Δ1 exceeds the preset deviation threshold, it means that the stack voltage of the battery stack acquired through P2-V is inconsistent with the sum of the individual cell voltages of all the battery cells within it. If battery cell fault detection is performed based on the potential signal data of each cell that failed the verification, the reliability of the detection results cannot be guaranteed. At this time, a verification failure message can be output to prompt the operator to check the sampling harness connection of the voltage detection interface or to re-acquire data.

[0035] This application's embodiments verify the integrity of sampling channel connections, individual unit voltage data, and number mapping by comparing the sum of each unit's voltage with the stack voltage. This reduces false fault detection caused by poor sampling channel connections, missing data, or incorrect number mapping, effectively improving the accuracy and reliability of fault detection. Furthermore, when verification fails, invalid fault detection is avoided based on unreliable data, reducing wasted computational resources and facilitating quick problem identification by operators, thus improving overall detection efficiency.

[0036] The fault detection phase includes three detection methods: rapid OCV detection of individual battery cells, OCV degradation detection during static storage, and charge / discharge efficiency detection. In actual testing, one or more of these methods can be selected based on the specific operating conditions.

[0037] In some embodiments of this application, the preset detection conditions include the battery module being in a static state. A static state refers to the battery module being left idle for a preset time after charging and discharging has stopped, allowing the main circuit of the battery module to have essentially no current. When the battery module is in a static state, it can be considered that the battery module meets the preset detection conditions. For example, after stopping charging and discharging the battery module and leaving it idle for 30 minutes, the main circuit current of the battery module is detected. If the main circuit current is less than 1% of the rated current of the battery module, it indicates that the OCV (Open Circuit Voltage) of each battery cell tends to stabilize, meaning the battery module is in a static state.

[0038] For rapid OCV detection of individual battery cells, fault detection results are obtained by performing fault detection on each cell based on its voltage, including:

[0039] S221. Obtain the average value of the individual cell voltage in each battery stack at the first moment.

[0040] At the first moment t0 when the battery module is in a static state, the detection device collects the node voltage signal through P2-V to obtain the individual cell voltage of each battery cell in the battery stack at the first moment t0. The individual cell voltage at this time is the open circuit voltage OCV.

[0041] S222. When the second deviation between the single cell voltage of a battery cell and the average single cell voltage of the corresponding battery stack exceeds the first preset threshold, the battery cell is determined to be a faulty battery cell, and the faulty cell number and the faulty stack number are determined based on the preset mapping relationship.

[0042] Based on the individual cell voltages of each battery cell within each battery stack at the first time t0, the average individual cell voltage of each battery cell within each battery stack is obtained. The detection equipment calculates the absolute value of the difference between the individual cell voltage of each battery cell within each battery stack and the average individual cell voltage, which is used as a second deviation. The second deviation is compared with a first preset threshold, and the battery cell corresponding to the second deviation exceeding the first preset threshold is identified as a faulty battery cell. Based on a preset mapping relationship, the faulty battery cell number and the faulty stack number are determined to quickly locate the position of the faulty battery cell.

[0043] The first preset threshold is a configurable fixed value, set according to the voltage level and actual operating conditions of the battery module under test. Those skilled in the art can flexibly set the first preset threshold according to actual needs. The preset mapping relationship can be a mapping relationship table pre-stored in the testing equipment, or it can be calibrated on-site during the testing process. This application embodiment does not limit this.

[0044] For example, for battery stack ST1, where the average voltage V of each cell is at the first time t0 avg =(V1+V2+V3+V4) / 4, then calculate the second deviation between the individual cell voltage of each cell in the battery stack and the average value of the individual cell voltages mentioned above, and determine the faulty cell using the method described in the above embodiment. For example, the second deviation Δ of CELL1 2_1 =|V1-V avg |, if Δ 2_1 If the value is greater than the first preset threshold, then CELL1 can be identified as a faulty battery cell, and the faulty cell number can be identified as CELL1 and the faulty stack number as ST1.

[0045] This application embodiment uses P2-V synchronous acquisition of the open-circuit voltage (OCV) of each battery cell to perform rapid OCV detection and determine the presence of faulty battery cells. Since each battery stack calculates its own average value as a benchmark, even if there are differences between different battery stacks, faulty battery cells with poor voltage consistency can still be independently identified within each battery stack, effectively reducing potential misjudgments or omissions when using fixed absolute voltage thresholds. Furthermore, by acquiring the OCV of all battery cells simultaneously, without needing to measure each cell individually, the detection time is significantly shortened.

[0046] In some embodiments of this application, for static OCV attenuation detection, the preset detection conditions include the battery module being in a static state. In this case, it is also used to perform battery cell fault detection based on the voltage of each individual cell to obtain the fault detection result, including:

[0047] S231. Obtain the third deviation between the individual cell voltage at the first time t0 and the individual cell voltage at the second time t1 in each battery stack, and obtain the average value of the third deviation.

[0048] There is a preset time interval Δt between the second time t1 and the first time t0. The detection device collects the individual cell voltage V of each battery cell in the battery stack at the first time t0 of the battery module. t0 Then, the battery modules are left to stand still for Δt until the second time t1, and the individual cell voltage V of each battery cell in the battery stack is collected at the second time t1. t1 The third deviation of each battery cell is Δ3 = V t1 -V t0 This refers to the OCV decay of the battery cell within a preset time interval, and the average value of the third deviation of each battery cell is calculated to represent the normal decay level of the battery stack as a whole.

[0049] S232. When the fourth deviation between the third deviation and the average of the third deviation exceeds the second preset threshold, the battery cell corresponding to the third deviation is determined to be a faulty battery cell, and the faulty cell number and faulty stack number are determined based on the preset mapping relationship.

[0050] For example, taking battery stack ST1 as an example, the third deviation of individual cells CELL1-CELL4 are respectively Δ 3_1 Δ 3_2 Δ 3_3 Δ 3_4 Its average value Δ agv =(Δ 3_1 +Δ 3_2 +Δ 3_3 +Δ 3_4 ) / 4, calculate the third deviation of each battery cell relative to its average value and the fourth deviation Δ4. If the fourth deviation Δ4_2 of battery cell CELL2 exceeds the second preset threshold set according to the battery degradation OCV, then CELL can be identified as a faulty battery cell, and the faulty cell number is determined as CELL2 and the fault pile number is ST1.

[0051] This application's embodiments, through a static OCV decay detection method, can identify latent faults that might not be detected in a single rapid OCV test, such as abnormal self-discharge, separator abnormalities, or sealing failures. These faulty battery cells may not exhibit obvious voltage deviations in a single rapid OCV test, but their cell voltage will decrease faster over time than that of other normal cells. Combined with the aforementioned single-cell rapid OCV detection method, the two methods complement each other: single-cell rapid OCV detection is used to detect abnormalities in static cell voltage deviating from the average level, while static OCV decay detection is used to detect latent faults such as abnormal dynamic cell voltage decay, thereby improving the comprehensiveness and accuracy of fault detection.

[0052] In some embodiments of this application, the battery module further includes a current detection interface P22 and a main detection interface P1 disposed on the first housing 10. The current detection interface P22 includes a current sampling channel P2-I connected to the current sensor inside the battery module.

[0053] The main detection interface P1 connects the positive and negative terminals of the battery module under test to the corresponding ports of the detection equipment. This allows the detection equipment to acquire the module-level total voltage and current, and to apply a preset voltage or load to the battery module during charge / discharge efficiency testing, thus placing the battery module in a charge / discharge state. The current detection interface P22 connects to the signal terminals of various current sensors installed in the battery module, such as the main circuit current sensor and the stack branch current sensor, to obtain the current data required for efficiency calculation. P21 and P22 both belong to the battery voltage / current detection port group P2, but they are independent of each other in their signal transmission paths and do not share sampling harnesses to reduce mutual interference between voltage and current sampling.

[0054] For charge / discharge efficiency testing, the preset testing conditions include controlling the battery module to be in a charge / discharge state through the main testing interface P1. The method also includes:

[0055] S241. Collect the charge and discharge current of each battery stack and / or the total charge and discharge current of the battery module through the current sampling channel P2-I, and collect the total voltage of the battery module through the main detection interface P1.

[0056] The current detection interface P22 includes a current sampling channel P2-I. The detection device acquires the current signals output by each current sensor through P2-I, thereby obtaining the stack charge / discharge current of each battery stack and / or the total charge / discharge current of the battery module, and acquires the total voltage of the battery module through P1.

[0057] S242. Based on the stack charge and discharge current and / or total charge and discharge current, total voltage, and individual cell voltage of each battery cell, perform battery cell fault detection to obtain fault detection results.

[0058] In some embodiments of this application, fault detection results are obtained by performing battery cell fault detection based on the stack charge / discharge current and / or total charge / discharge current, total voltage, and the individual cell voltage of each battery cell, including:

[0059] S242-1. Calculate the efficiency of the battery module based on the stack charge / discharge current and / or total charge / discharge current, and total voltage.

[0060] In some embodiments of this application, efficiency includes at least one of coulombic efficiency, energy efficiency, and voltage efficiency. A preset charge / discharge cycle includes a charging phase and a discharging phase.

[0061] Within a preset charge / discharge cycle, the coulombic efficiency CE = discharge capacity / charge capacity × 100%, wherein the detection device integrates the stack charge / discharge current and / or total charge / discharge current over time during the discharge phase to obtain the discharge capacity of the battery stack and / or battery module; and integrates the stack charge / discharge current and / or total charge / discharge current over time during the charging phase to obtain the charge capacity of the battery stack and / or battery module.

[0062] Energy efficiency EE = Discharge energy / Charge energy × 100%. In the discharge phase, the detection device integrates the product of the charge-discharge current and / or the total charge-discharge current and the total voltage over time to obtain the discharge energy. In the charging phase, the device integrates the product of the charge-discharge current and / or the total charge-discharge current and the total voltage over time to obtain the charging energy.

[0063] Voltage efficiency VE = EE / CE × 100%, or calculated as average discharge voltage / average charging voltage × 100%, where the average discharge voltage is obtained by dividing the discharge energy by the discharge quantity, and the average charging voltage is obtained by dividing the charging energy by the charging quantity.

[0064] S242-2. Based on efficiency and the individual cell voltage of each battery cell, fault detection results are obtained by performing battery cell fault detection.

[0065] The testing equipment performs battery cell fault detection based on at least one of the calculated coulombic efficiency CE, energy efficiency EE, and voltage efficiency VE, combined with the cell operating voltage collected during the charging and discharging process, or the cell OCV obtained through the aforementioned embodiments.

[0066] For example, when the detection equipment determines that the coulombic efficiency (CE) is low, such as CE < 90%, it indicates that the battery module may have problems with excessive self-discharge or charge consumption by side reactions. In this case, the detection equipment can combine the results of the aforementioned static OCV degradation detection. If a certain battery cell is marked as a faulty battery cell in the static OCV degradation detection, and the coulombic efficiency calculation shows that the overall coulombic efficiency of the battery stack is low, then that battery cell is the main faulty battery cell causing the decrease in coulombic efficiency.

[0067] When the testing equipment determines that the energy efficiency (EE) of the battery module is low, such as EE < 70%, it indicates that the battery module has significant energy loss during charging and discharging. In this case, the testing equipment can retrieve the individual operating voltage data of each battery cell collected through P2-V during the charging and discharging process to analyze the voltage response differences of each battery cell within the same battery stack.

[0068] When the testing equipment determines that the voltage efficiency (VE) is low, such as VE < 80%, it indicates that the battery module experiences significant voltage loss during charging and discharging. Low voltage efficiency is usually related to increased internal resistance or intensified polarization of individual battery cells. By analyzing the degree to which the operating voltage of each battery cell deviates from the average value during charging and discharging, the testing equipment can pinpoint the faulty battery cell causing the voltage efficiency decrease.

[0069] The final fault detection results generated by the testing equipment may include: overall efficiency value, abnormal voltage response markers for each battery cell, faulty battery cell number, faulty stack number, and possible causes of efficiency degradation.

[0070] This application embodiment, through charge and discharge efficiency detection, can not only calculate the coulombic efficiency, energy efficiency, and voltage efficiency of the battery stack, but also correlate efficiency anomalies with the operating voltage response of specific battery cells, thereby explaining the source of efficiency decline and quickly locating the specific battery cells contributing to efficiency loss.

[0071] In some embodiments of this application, the method further includes: acquiring the total charging and discharging current of the battery module through the main detection interface P1.

[0072] The testing equipment is connected to the signal output terminal of the current sensor via P1 to collect the total charging and discharging current flowing through the positive and negative terminals of the battery module. During the charging and discharging efficiency testing process, if the battery module is taken as the calculation object, the total charging and discharging current is the total charging and discharging current of the battery module, thus obtaining the overall coulombic efficiency, energy efficiency, and voltage efficiency of the battery module.

[0073] This application embodiment can calculate the overall coulombic efficiency, energy efficiency, and voltage efficiency of the battery module by collecting the total charging and discharging current of the battery module, so as to evaluate the battery module as a whole. It can also be cross-verified with the efficiency of the battery stack obtained in the aforementioned embodiment.

[0074] In some embodiments of this application, the parallel voltage sampling channel P2-V is connected to a voltage sampling resistor, the impedance of which is greater than the internal resistance of the corresponding battery cell.

[0075] For example, the impedance of the voltage sampling resistor is at least 10 times the internal resistance of the battery cell, ensuring that the current flowing through the sampling channel is much smaller than the current flowing through the main circuit of the battery stack. This guarantees sampling accuracy while reducing the substantial impact of the sampling channel on the potential distribution inside the battery stack. By placing the voltage sampling resistor in each sampling channel of P2-V, when the detection device is connected to the battery module through P21, the high impedance characteristics of each sampling channel greatly reduce the impact of the sampling circuit on the normal operation of the battery stack, improving the safety of the detection process. Those skilled in the art can select the appropriate impedance value of the voltage sampling resistor according to actual needs.

[0076] Figure 3 This is a schematic diagram of the structure of a detection device for a flow battery module provided in some embodiments of this application. For example... Figure 3 As shown, the battery module includes a first housing 10, at least one battery stack ST disposed within the first housing 10, and a main detection interface P1, a voltage detection interface P21, and a current detection interface P22 disposed on the first housing 10. Each battery stack includes multiple battery cells. The voltage detection interface P21 includes parallel voltage sampling channels P2-V corresponding one-to-one with the potential nodes of each battery cell in the battery module. The current detection interface P22 includes a current sampling channel P2-I connected to a current sensor inside the battery module. The detection device includes: a second housing 20; an adapter interface disposed on the second housing 20 and adapted to the main detection interface P1, the voltage detection interface P21, and the current detection interface P22 respectively; and a controller 30 disposed within the second housing 120. The controller 30 is connected to the adapter interface and is used to execute the detection method of the flow battery module described in the above embodiment.

[0077] This embodiment of the application achieves plug-and-play electrical connection between the testing device and the battery module by setting adapter interfaces on the second housing that are respectively adapted to the main detection interface P1, voltage detection interface P21, and current detection interface P22 on the first housing, thereby reducing the operational threshold and preparation workload for on-site testing. Simultaneously, the controller 30, located within the second housing, connects to each detection interface of the battery module through the adapter interfaces, enabling automatic execution of the testing methods described in the aforementioned embodiments. This achieves full automation from electrical connection to fault diagnosis, reducing manual intervention and improving testing efficiency and consistency. Furthermore, since the testing device is independent of the battery module, the same testing device can sequentially test multiple battery modules, reducing the cost and complexity of battery module testing. It also facilitates centralized maintenance and software upgrades of the testing device, exhibiting good versatility and practicality.

[0078] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0079] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0080] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0081] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0082] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for testing a flow battery module, characterized in that, The battery module includes a first housing, at least one battery stack disposed within the first housing, and a voltage detection interface disposed on the first housing. Each battery stack includes multiple individual battery cells. The voltage detection interface includes parallel voltage sampling channels corresponding one-to-one with the potential nodes of each individual battery cell in the battery module. The method includes: When the battery module meets the preset detection conditions, the stack voltage of each battery stack and the individual voltage of each battery cell are collected through the parallel voltage sampling channel. The stack voltage and the individual cell voltage are tested and verified. After the verification is passed, the individual cell voltage is used to detect the individual cell fault and obtain the fault detection result. The fault detection result includes the faulty individual cell, the faulty individual cell number and the faulty stack number of the stack in which the faulty individual cell is located.

2. The detection method for a flow battery module according to claim 1, characterized in that, The detection and verification based on the stack voltage and the individual cell voltage includes: Based on the first deviation between the stack voltage of each battery stack and the sum of the individual cell voltages of the battery cells within each battery stack, it is determined whether the parallel sampling channel and the individual cell voltage corresponding to each battery stack are complete.

3. The detection method for a flow battery module according to claim 1, characterized in that, The preset detection conditions include the battery module being in a static state, and the step of obtaining fault detection results by detecting faults in individual battery cells based on their voltages includes: Obtain the average value of the individual cell voltages of the battery cells in each battery stack at the first moment; When the second deviation between the individual cell voltage of the battery cell and the average individual cell voltage of the corresponding battery stack exceeds a first preset threshold, the battery cell is determined to be the faulty battery cell, and the faulty cell number and the faulty stack number are determined based on a preset mapping relationship.

4. The detection method for a flow battery module according to claim 1, characterized in that, The preset detection conditions include the battery module being in a static state, and the step of obtaining fault detection results by detecting faults in individual battery cells based on their voltages includes: Obtain the third deviation between the individual cell voltage at a first moment and the individual cell voltage at a second moment within each of the battery stacks, and obtain the average value of the third deviation. When the fourth deviation between the third deviation and the average of the third deviation exceeds the second preset threshold, the battery cell corresponding to the third deviation is determined to be the faulty battery cell, and the faulty cell number and the faulty stack number are determined based on the preset mapping relationship.

5. The detection method for a flow battery module according to any one of claims 1-4, characterized in that, The battery module further includes a current detection interface and a main detection interface disposed on the first housing. The current detection interface includes a current sampling channel connected to a current sensor inside the battery module. The preset detection conditions include controlling the battery module to be in a charging and discharging state through the main detection interface. The method further includes: The current sampling channel is used to collect the charge and discharge current of each battery stack and / or the total charge and discharge current of the battery module, and the main detection interface is used to collect the total voltage of the battery module. The fault detection result is obtained by performing battery cell fault detection based on the stack charge / discharge current and / or the total charge / discharge current, the total voltage, and the individual cell voltage of each battery cell.

6. The detection method for a flow battery module according to claim 5, characterized in that, The method of obtaining the fault detection result by performing battery cell fault detection based on the stack charge / discharge current and / or the total charge / discharge current, the total voltage, and the individual cell voltage of each battery cell includes: The efficiency of the battery module is calculated based on the charge / discharge current and / or the total charge / discharge current, and the total voltage. The fault detection results are obtained by performing battery cell fault detection based on the efficiency and the individual cell voltage of each battery cell.

7. The detection method for a flow battery module according to claim 6, characterized in that, The efficiency includes at least one of coulombic efficiency, energy efficiency, and voltage efficiency.

8. The detection method for a flow battery module according to claim 5, characterized in that, The method further includes: collecting the total charging and discharging current of the battery module through the main detection interface.

9. The detection method for a flow battery module according to claim 1, characterized in that, The parallel voltage sampling channel is connected to a voltage sampling resistor, and the impedance of the voltage sampling resistor is greater than the internal resistance of the corresponding battery cell.

10. A detection device for a flow battery module, characterized in that, The battery module includes a first housing, at least one battery stack disposed within the first housing, and a main detection interface, a voltage detection interface, and a current detection interface disposed on the first housing. Each battery stack includes multiple battery cells. The voltage detection interface includes parallel voltage sampling channels corresponding one-to-one with the potential nodes of each battery cell in the battery module. The current detection interface includes a current sampling channel connected to a current sensor inside the battery module. The device includes: Second shell; An adapter interface is provided on the second housing and is adapted to the main detection interface, the voltage detection interface and the current detection interface respectively; A controller is disposed within the second housing and is connected to the adapter interface. The controller is used to execute the detection method for the flow battery module as described in any one of claims 1-9.

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