Method, device and equipment for diagnosing and locating battery short circuit faults in energy storage systems

Abstract

The present invention provides a method, device, and equipment for diagnosing and locating battery short-circuit faults in an energy storage system, which can be applied to the technical field of energy storage system fault detection. The method includes: performing real-time voltage acquisition on battery cells to obtain the voltage changes of multiple battery cells within adjacent sampling moments; obtaining the voltage change characteristics of multiple battery pairs based on the absolute value of the difference between the voltage changes of two adjacent battery cells in multiple battery pairs; obtaining the braking coefficients corresponding to the multiple battery pairs based on the information of the multiple battery cells; determining the fault adaptive thresholds of the multiple battery pairs based on the braking coefficients corresponding to the multiple battery pairs and the absolute value of the sum of the voltage changes of two adjacent battery cells in the multiple battery pairs; and determining the target battery pairs that have experienced short-circuit faults from the multiple battery pairs based on the fault adaptive thresholds and voltage change characteristics of the multiple battery pairs.

Description

Technical Field

[0001] The present invention relates to the technical field of battery fault detection, and more specifically, to a method, device and equipment for diagnosing and locating a battery short circuit fault based on an energy storage system. Background Art

[0002] Lithium-ion batteries are the core energy carriers of electrochemical energy storage systems. When a lithium-ion battery experiences an external short circuit due to mechanical damage, electrolyte leakage or insulation failure, the short-circuit current can increase to 10 to 30 times the normal operating current within milliseconds, causing the temperature of the battery cell to rise sharply and triggering safety issues such as thermal runaway.

[0003] In the process of realizing the concept of the present invention, it was found through research that the passive protection strategy based on fixed thresholds in the related art is difficult to meet the real-time protection requirements. Summary of the Invention

[0004] In view of this, the present invention provides a method, device and equipment for diagnosing and locating battery short circuit faults in an energy storage system.

[0005] One aspect of the present invention provides a method for diagnosing and locating battery short-circuit faults in an energy storage system, comprising: performing real-time voltage acquisition on multiple battery cells in a target energy storage system to obtain voltage changes of each of the multiple battery cells within adjacent sampling moments; obtaining voltage change characteristics of each of the multiple battery pairs based on the absolute value of the difference between the voltage changes of two adjacent battery cells in the multiple battery pairs; obtaining braking coefficients corresponding to each of the multiple battery pairs based on charge state information, health state information, and operating condition information of each of the multiple battery cells; determining fault adaptive thresholds of each of the multiple battery pairs based on the braking coefficients corresponding to each of the multiple battery pairs and the absolute value of the sum of the voltage changes of two adjacent battery cells in the multiple battery pairs; and determining, from the multiple battery pairs, target battery pairs in which short-circuit faults have occurred based on the fault adaptive thresholds and voltage change characteristics of the multiple battery pairs.

[0006] According to an embodiment of the present invention, the number of the plurality of battery pairs is N; based on the respective fault adaptive thresholds and voltage variation characteristics of the plurality of battery pairs, a target battery pair in which a short circuit fault has occurred is determined from the plurality of battery pairs, including: for the nth battery pair, in response to determining that the voltage variation characteristic is greater than the fault adaptive threshold, determining the nth battery pair as the target battery pair, wherein n∈N and n and N are positive integers.

[0007] According to an embodiment of the present invention, based on the state of charge information, health status information and operating condition information of each of the multiple battery cells, a braking coefficient corresponding to each of the multiple battery pairs is obtained, including: constructing a mapping relationship between historical data and braking coefficient based on the historical data of each of the multiple battery cells, wherein the historical data includes historical state of charge information, historical health status information and historical operating condition information; and determining the braking coefficient corresponding to each of the multiple battery pairs from the mapping relationship according to the current state of charge information, health status information and operating condition information of each of the multiple battery cells.

[0008] According to an embodiment of the present invention, based on the current state of charge information, health status information and operating condition information of each of the multiple battery cells, the braking coefficients corresponding to each of the multiple battery pairs are determined from a mapping relationship, including: in response to the current state of charge information, health status information and operating condition information of each of the multiple battery cells falling into historical data, reading a first braking coefficient from the mapping relationship; in response to the current state of charge information, health status information and operating condition information of each of the multiple battery cells not falling into historical data, determining a corresponding interpolation point from the mapping relationship to interpolate the interpolation point to obtain a second braking coefficient.

[0009] According to an embodiment of the present invention, a corresponding interpolation point is determined from a mapping relationship to interpolate the interpolation point to obtain a second braking coefficient, and the method also includes: obtaining fault verification information for a target battery pair; adjusting the second braking coefficient based on the fault verification information so that the fault verification information corresponding to the target battery pair detected based on the adjusted second braking coefficient meets a predetermined condition; and determining the adjusted second braking coefficient as the target braking coefficient corresponding to the interpolation point.

[0010] According to an embodiment of the present invention, the above-mentioned diagnosis and positioning method further includes: determining a battery cell with a negative voltage variation in the target battery pair as a faulty cell.

[0011] According to an embodiment of the present invention, the above-mentioned diagnosis and positioning method further includes: determining the location where the fault occurs according to the location of the faulty cell.

[0012] According to an embodiment of the present invention, two adjacent battery cells in a battery pair belong to the same battery cluster.

[0013] Another aspect of the present invention provides a device for diagnosing and locating a battery short circuit fault in an energy storage system, comprising:

[0014] The acquisition module is used to collect the real-time voltage of multiple battery cells in the target energy storage system to obtain the voltage changes of each of the multiple battery cells within adjacent sampling moments;

[0015] A first obtaining module is configured to obtain voltage variation characteristics of each of the plurality of battery pairs according to an absolute value of a difference between voltage variations of two adjacent battery cells in the plurality of battery pairs;

[0016] A second obtaining module is configured to obtain a braking coefficient corresponding to each of the plurality of battery pairs based on the state of charge information, health state information, and operating condition information of each of the plurality of battery cells;

[0017] A first determination module is configured to determine a fault adaptive threshold value for each of the plurality of battery pairs based on a braking coefficient corresponding to each of the plurality of battery pairs and an absolute value of a sum of voltage changes of two adjacent battery cells in the plurality of battery pairs;

[0018] The second determining module is configured to determine a target battery pair having a short circuit fault from among the multiple battery pairs based on respective fault adaptive thresholds and voltage variation characteristics of the multiple battery pairs.

[0019] Another aspect of the present invention provides an electronic device, comprising:

[0020] one or more processors;

[0021] a memory for storing one or more programs,

[0022] When one or more programs are executed by one or more processors, the one or more processors implement the diagnosis and positioning method as described above.

[0023] According to an embodiment of the present invention, the difference in voltage change between two adjacent battery cells in a battery pair of a target energy storage system to be determined within adjacent sampling moments is used as a voltage change feature for comparison with a fault adaptive threshold to achieve short-circuit fault judgment. This breaks the technical barrier of related technologies that fault judgment is performed based solely on the real-time voltage of a single battery cell and a fixed threshold. At the same time, the fault adaptive threshold is set based on the difference in voltage change between the two battery cells in the battery pair, that is, it is updated in real time according to the voltage change of the battery cell itself and is not limited by the battery cell's own state. In addition, based on the state of charge information, health status information, and operating condition information of each of the multiple battery cells, the braking coefficients corresponding to the multiple battery pairs are determined to adjust the fault adaptive threshold, thereby avoiding the voltage change being too small to be identified during a micro-short-circuit fault. Therefore, it has a certain degree of universality for different application scenarios, and while having a small amount of calculation, it achieves accurate judgment and positioning of battery short-circuit faults in energy storage systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A flow chart showing a method for diagnosing and locating a battery short circuit fault in an energy storage system according to an embodiment of the present invention is shown;

[0025] Figure 2a A circuit diagram of a battery external short circuit fault in a target energy storage system according to an embodiment of the present invention is shown;

[0026] Figure 2b An equivalent circuit diagram of a battery external short circuit fault in a target energy storage system according to an embodiment of the present invention is shown;

[0027] Figure 3 A waveform diagram showing the change in the terminal voltage of battery cells at different positions as the number of short-circuited batteries is shown according to an embodiment of the present invention;

[0028] Figure 4 A block diagram of a device for diagnosing and locating a battery short circuit fault in an energy storage system according to an embodiment of the present invention is shown;

[0029] Figure 5 A block diagram of an electronic device suitable for implementing a method for diagnosing and locating a battery short circuit fault in an energy storage system according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0030] 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 present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concept of the present invention.

[0031] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the presence of the features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.

[0032] 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 should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0033] When expressions such as "at least one of A, B, and C, etc." are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0034] During the process of realizing the inventive concept of the present invention, it was found through research that external short-circuit faults of lithium-ion battery packs are highly sudden and destructive, and therefore have attracted much attention in the fault diagnosis of electrochemical energy storage systems.

[0035] A battery management system in the related art collects the real-time voltage value of a single battery cell and compares it with a predetermined threshold value obtained from experience to detect whether the battery cell is operating in a normal state.

[0036] For example, the upper cutoff voltage of a lithium iron phosphate battery is 3.65V, and the lower cutoff voltage is 2.5V. During normal battery operation, the voltage is 3.3V at a certain point. However, when an external short circuit occurs, the voltage may plummet to 1V. Ideally, this would indicate a battery failure and immediately disconnect the circuit breaker. However, in actual operation, if a high-resistance external short circuit occurs, the voltage may only drop to 3.1V, which does not exceed the lower cutoff voltage. Therefore, for micro-short circuits like these, the system has difficulty identifying the occurrence of the fault, which can lead to a series of safety hazards.

[0037] In addition, the battery's own aging and ambient temperature will affect the voltage value. Judging only based on a fixed threshold will result in large errors, and the determination of the threshold also needs to rely on a large amount of experimental data.

[0038] In order to improve the accuracy of fault identification, related technologies also use data-driven intelligent diagnostic algorithms. However, for large-scale energy storage systems, the calculation base of thousands of battery cells brings about an overly complex amount of calculation.

[0039] In view of this, an embodiment of the present invention provides a method for diagnosing and locating battery short-circuit faults based on an energy storage system, comprising: performing real-time voltage acquisition on multiple battery cells in a target energy storage system to obtain voltage changes of each of the multiple battery cells within adjacent sampling moments; obtaining voltage change characteristics of each of the multiple battery pairs based on the absolute value of the difference between the voltage changes of two adjacent battery cells in the multiple battery pairs; obtaining braking coefficients corresponding to each of the multiple battery pairs based on the state of charge information, health status information and operating condition information of each of the multiple battery cells; determining fault adaptive thresholds of each of the multiple battery pairs based on the braking coefficients corresponding to each of the multiple battery pairs and the absolute value of the sum of the voltage changes of two adjacent battery cells in the multiple battery pairs; and determining a target battery pair in which a short-circuit fault has occurred from the multiple battery pairs based on the fault adaptive thresholds and voltage change characteristics of the multiple battery pairs.

[0040] Figure 1 A flow chart of a method for diagnosing and locating a battery short circuit fault in an energy storage system according to an embodiment of the present invention is shown.

[0041] like Figure 1 As shown, the method 100 includes operations S110 to S150.

[0042] In operation S110 , real-time voltage acquisition is performed on a plurality of battery cells in a target energy storage system to obtain voltage changes of the plurality of battery cells at adjacent sampling moments.

[0043] In operation S120 , voltage variation characteristics of each of the plurality of battery pairs are obtained according to the absolute value of the difference between the voltage variation amounts of two adjacent battery cells in the plurality of battery pairs.

[0044] In operation S130 , a braking coefficient corresponding to each of the plurality of battery pairs is obtained based on the state of charge information, health state information, and operating condition information of each of the plurality of battery cells.

[0045] In operation S140 , fault adaptive thresholds of the battery pairs are determined according to the braking coefficients corresponding to the battery pairs and the absolute value of the sum of voltage changes of two adjacent battery cells in the battery pairs.

[0046] In operation S150 , a target battery pair in which a short circuit fault has occurred is determined from among the plurality of battery pairs based on the respective fault adaptive thresholds and voltage variation characteristics of the plurality of battery pairs.

[0047] According to an embodiment of the present invention, a battery management system (BMS) can be used to collect real-time voltage data for each battery cell in a target energy storage system. Based on the data collected, a voltage-time curve for each battery cell can be obtained. The resulting voltage-time curve can then be used to determine the voltage change for each battery cell at each adjacent sampling moment. The target energy storage system can be, for example, an energy storage power station or an electric vehicle's energy storage system.

[0048] For example, for the i-th battery cell, the voltage change between sampling time t and sampling time t-1 is It can be expressed as the following formula (1).

[0049] (1)

[0050] in, represents the voltage of the i-th battery cell at sampling time t, represents the voltage of the i-th battery cell at sampling time t-1.

[0051] According to an embodiment of the present invention, the ith battery cell and the i-1th battery cell are adjacent to each other, forming a battery pair. Therefore, the voltage variation characteristic shown in the following formula (2) can be obtained: .

[0052] (2)

[0053] in, is the voltage change of the i-1th battery cell between sampling time t and sampling time t-1.

[0054] Correspondingly, the i-th battery cell and the (i+1)-th battery cell are also adjacent and can also form a battery pair.

[0055] In order to better understand the voltage and current changes of each battery cell when a battery short circuit fault occurs in the target energy storage system, the following will take the case of only a single faulty battery cluster as an example. Figure 2a and Figure 2b Further analysis is carried out in combination with the loop current equation.

[0056] Figure 2a A circuit diagram of a battery external short circuit fault in a target energy storage system according to an embodiment of the present invention is shown.

[0057] Figure 2b An equivalent circuit diagram of a battery external short circuit fault in a target energy storage system according to an embodiment of the present invention is shown.

[0058] like Figure 2a As shown, the target system includes M battery clusters similar to the battery cluster 210 connected in parallel. Each battery cluster includes a plurality of battery cells, and two adjacent battery cells form a battery pair 221 .

[0059] Among them, the battery pack between battery cell B and battery cell C is short-circuited due to factors such as electrolyte leakage, loose connection parts, and mechanical vibration. This is equivalent to the direct connection between the positive electrode of battery cell B and the negative electrode of battery cell C, which can be regarded as having a short-circuit resistance R s , the battery cluster where battery cells B and battery cells C are located is a faulty battery cluster, and the equivalent load resistance R L Connected in parallel to M battery clusters.

[0060] For ease of calculation, a battery cell or battery pack can be considered as a voltage source and an equivalent resistor connected in series.

[0061] like Figure 2b As shown, due to Figure 2b and Figure 2a Correspondingly, the equivalent branch represents the equivalent branch of M-1 battery clusters excluding the faulty battery cluster, where U eN Represents the equivalent voltage source of all battery cells corresponding to the equivalent branch, R eN The equivalent branch represents the battery pack between battery cell B and battery cell C, where U eSRepresents the equivalent voltage source of all battery cells corresponding to the equivalent branch, R eS Indicates the equivalent resistance of all battery cells corresponding to the equivalent branch. The equivalent branch represents the battery pack on the left side of battery cell B, U eF1 Represents the equivalent voltage source of all battery cells corresponding to the equivalent branch, R eF1 Indicates the equivalent resistance of all battery cells corresponding to the equivalent branch. The equivalent branch represents the battery pack on the right side of battery cell C, U eF2 Represents the equivalent voltage source of all battery cells corresponding to the equivalent branch, R eF2 =I1, I2, and I3 represent the currents in the loops indicated by arrows.

[0062] According to an embodiment of the present invention, a loop current method can be used to construct a loop current equation as shown in the following equation (3).

[0063] (3)

[0064] Among them, B b is the loop matrix, T represents the matrix transpose symbol, Z b is the impedance matrix, U bs is the voltage source matrix, I b is the current matrix, and satisfies the following equations (4) to (7) respectively.

[0065] (4)

[0066] (5)

[0067] (6)

[0068] (7)

[0069] According to an embodiment of the present invention, taking each battery cluster including Y batteries as an example, the short-circuit location is the xth battery, the number of short-circuited batteries is X, the internal resistance of each battery cell is R0, the open-circuit voltage is U0, and before the short-circuit fault, the constant discharge current of the battery is I.

[0070] Therefore, R eN 、U eN 、R eF1 、U eF1 、R eS 、U eS 、R eF2 、U eF2 、R L It can be expressed as the following equations (8) to (12).

[0071] (8)

[0072] (9)

[0073] (10)

[0074] (11)

[0075] (12)

[0076] According to an embodiment of the present invention, by combining the above formulas (3) to (12), the terminal voltage of the equivalent branch and a single battery cell in the equivalent branch can be obtained as shown in the following formula (13): .

[0077] (13)

[0078] in, represents the current in the equivalent branch, The current of the equivalent branch Equal to .

[0079] Terminal voltage of a single battery cell in the equivalent branch It can be expressed as the following formula (14).

[0080] (14)

[0081] in, represents the current in the equivalent branch, and .

[0082] Pick , the trend of the terminal voltage of battery cells at different positions changing with the number of short-circuited batteries as X is analyzed.

[0083] Figure 3 The waveform diagram shows how the terminal voltage of battery cells at different positions changes with the number of short-circuited batteries according to an embodiment of the present invention.

[0084] like Figure 3 As shown in the figure, the horizontal axis represents the number of short-circuited cells, and the vertical axis represents the terminal voltage of the battery cells. It can be seen that the terminal voltage of the short-circuited battery cells decreases as the number of short-circuited cells increases, while the terminal voltage of the battery cells other than the short-circuited battery cell in the faulty battery cluster increases as the number of short-circuited cells increases. Therefore, after an external short-circuit fault occurs, the voltages on the left and right sides of the fault point will show opposite change trends.

[0085] According to an embodiment of the present invention, when an equivalent branch is short-circuited, an additional discharge loop is formed. This increases the discharge current of the short-circuited battery cell and causes a transient drop in the terminal voltage. However, since the total voltage of the faulty battery cluster drops after a short circuit, and the equivalent branch injects charging current into the faulty battery cluster, the terminal voltage of the battery cells in the equivalent branch and the equivalent branch will transiently increase. This means that the voltage changes of the battery cells on either side of the fault point are in opposite directions.

[0086] For example, a battery cluster to be determined in the target energy storage system includes 10 battery cells connected in series, which are numbered G1, G2, G3, G4, G5, G6, G7, G8, G9, G10, G11, G12, G13, G14, G15, G16, G17, G18, G19, G20, G21, G22, G23, G24, G5, G6, G7, G8 10 In the case that short circuit faults occur in G3, G4, and G5, for the battery pair composed of G2 and G3, the fault point can be determined to be between G2 and G3 based on the voltage changes of the two battery cells. For the battery pair composed of G3 and G4, since G3 and G4 are both short-circuited, the voltages both drop. For the battery pair composed of G4 and G5, since G4 and G5 are both short-circuited, the voltages both drop. For the battery pair composed of G5 and G6, another fault point can be determined to be between G5 and G6 based on the voltage changes of the two battery cells. Therefore, it can be determined that the battery cells between the two fault points are both short-circuited. In the case where only G3 and G5 are short-circuited, for the battery pair composed of G2 and G3, the fault point can be determined to be between G2 and G3 based on the voltage change of each of the two battery cells. For the battery pair composed of G3 and G4, another fault point can be determined to be between G3 and G4 based on the voltage change of each of the two battery cells. Therefore, it can be determined that among G2, G3, and G4, only G3 is short-circuited. Similarly, it can be determined that among G4, G5, and G6, only G5 is short-circuited.

[0087] It can be seen from this that in order to determine the fault location, the voltage changes of two adjacent battery cells in each battery pair can be analyzed.

[0088] According to an embodiment of the present invention, before setting the threshold, the braking coefficient k corresponding to each of the multiple battery pairs can be obtained based on the charge state information, health state information and operating condition information of each of the multiple battery cells. The braking coefficient k ranges from 0.8 to 1.2.

[0089] Based on the above Figure 3 From the analysis, it can be seen that when there is a short-circuit fault battery cell in the battery pair, for this battery pair, the voltage change of one battery cell is negative and the voltage change of the other battery cell is positive. Therefore, the judgment threshold T can be set to the absolute value of the sum of the voltage changes of two adjacent battery cells in multiple battery pairs. The judgment threshold T can be expressed as the following formula (15).

[0090] (15)

[0091] According to an embodiment of the present invention, the fault adaptive threshold Q can be expressed as Q=kT.

[0092] According to an embodiment of the present invention, a target battery pair in which a short circuit fault has occurred can be determined from a plurality of battery pairs based on the respective fault adaptive thresholds and voltage variation characteristics of the plurality of battery pairs, wherein the target battery pair includes a non-short-circuited battery cell and a short-circuited battery cell.

[0093] It should be noted that the braking coefficient exists only to further improve the accuracy of the above-mentioned fault determination method. When the braking coefficient is 1 (or the braking coefficient is not considered), the above-mentioned battery short-circuit fault diagnosis and location method based on the energy storage system can also locate the short-circuit fault of the target energy storage system.

[0094] According to an embodiment of the present invention, the difference in voltage change between two adjacent battery cells in a battery pair of a target energy storage system to be determined within adjacent sampling moments is used as a voltage change feature for comparison with a fault adaptive threshold to achieve short-circuit fault judgment. This breaks the technical barrier of related technologies in which fault judgment is performed based solely on the real-time voltage of a single battery cell and a fixed threshold. At the same time, the fault adaptive threshold is set based on the difference in voltage change between the two battery cells in the battery pair, that is, it is updated in real time according to the voltage change of the battery cell itself and is not limited by the state of the battery cell itself. In addition, the braking coefficients corresponding to the multiple battery pairs are determined based on the state of charge information, health status information, and operating condition information of the multiple battery cells to adjust the fault adaptive threshold, thereby avoiding the voltage change being too small to be identified during a micro-short-circuit fault. Therefore, the present invention has a certain degree of universality for different application scenarios, and achieves accurate diagnosis and positioning of battery short-circuit faults in energy storage systems while reducing the amount of calculation.

[0095] According to an embodiment of the present invention, the number of the plurality of battery pairs is N; based on the respective fault adaptive thresholds and voltage variation characteristics of the plurality of battery pairs, a target battery pair in which a short circuit fault has occurred is determined from the plurality of battery pairs, including: for the nth battery pair, in response to determining that the voltage variation characteristic is greater than the fault adaptive threshold, determining the nth battery pair as the target battery pair, wherein n∈N and n and N are positive integers.

[0096] When the nth battery pair satisfies the following formula (16), the nth battery pair can be determined as the target battery pair.

[0097] (16)

[0098] in, The absolute value of the difference between the changes of the two battery cells in the nth battery pair, k n represents the braking coefficient of the nth battery pair, T n represents the discrimination threshold of the nth battery pair.

[0099] According to an embodiment of the present invention, during the short-circuit fault detection process of the target energy storage system, the detection results need to be sent to the host computer in real time. The host computer controls the disconnection of the circuit breaker based on the fault information in the detection results, so as to eliminate the fault as soon as possible and restore the normal operation of the target energy storage system.

[0100] According to an embodiment of the present invention, two adjacent battery cells in a battery pair belong to the same battery cluster.

[0101] According to an embodiment of the present invention, when two battery cells in a target battery pair belong to the same battery cluster, the fault type of the target energy storage system is intra-cluster short circuit.

[0102] According to an embodiment of the present invention, the above fault determination method is not limited to the battery cluster to which the two battery cells in the battery pair belong. Therefore, as long as the voltage variation characteristic is greater than the fault adaptive threshold, the external short circuit fault can be detected.

[0103] According to an embodiment of the present invention, based on the state of charge information, health status information and operating condition information of each of the multiple battery cells, a braking coefficient corresponding to each of the multiple battery pairs is obtained, including: constructing a mapping relationship between historical data and braking coefficient based on the historical data of each of the multiple battery cells, wherein the historical data includes historical state of charge information, historical health status information and historical operating condition information; and determining the braking coefficient corresponding to each of the multiple battery pairs from the mapping relationship according to the current state of charge information, health status information and operating condition information of each of the multiple battery cells.

[0104] According to an embodiment of the present invention, the mapping relationship between the historical data and the braking coefficient can be summarized by learning the historical data of each of the plurality of battery cells.

[0105] For example, for the nth battery pair, various historical data of the two battery cells in the nth battery pair can be arithmetic averaged or weighted averaged to construct a mapping relationship based on the average value of the historical data, wherein the operating condition information can be represented by current.

[0106] According to an embodiment of the present invention, based on the current state of charge information, health status information and operating condition information of each of the multiple battery cells, the braking coefficients corresponding to each of the multiple battery pairs are determined from a mapping relationship, including: in response to the current state of charge information, health status information and operating condition information of each of the multiple battery cells falling into historical data, reading a first braking coefficient from the mapping relationship; in response to the current state of charge information, health status information and operating condition information of each of the multiple battery cells not falling into historical data, determining a corresponding interpolation point from the mapping relationship to interpolate the interpolation point to obtain a second braking coefficient.

[0107] Since the mapping relationship is obtained by discretely collecting historical data, the state of charge information, health status information and operating condition information of the battery pair change in real time.

[0108] For example, extract part of the mapping relationship:

[0109] Discrete point P1: historical state of charge information is 60%, historical health status information is 0.8, historical operating condition information is 1C, and the corresponding braking coefficient is 0.8;

[0110] Discrete point P2: historical charge state information is 70%, historical health state information is 0.9, historical operating condition information is 2C, and the corresponding braking coefficient is 0.9.

[0111] When the current state of charge information, health status information and operating condition information of multiple battery cells fall into the historical data, for example: the state of charge information is exactly 60%, the health status information is exactly 0.8 and the operating condition information is exactly 1C, it coincides with the discrete point P1, and the first braking coefficient can be directly read as 0.8.

[0112] When the current state of charge information, health status information and operating condition information of multiple battery cells do not fall into the historical data, for example: when the state of charge information is 65%, the health status information is 0.85 and the operating condition information is 1.5C, it is exactly between the discrete point P1 and the discrete point P2. Therefore, an interpolation point can be determined between the discrete point P1 and the discrete point P2 for difference, and the second braking coefficient is 0.84.

[0113] According to an embodiment of the present invention, a corresponding interpolation point is determined from a mapping relationship to interpolate the interpolation point to obtain a second braking coefficient, and the method also includes: obtaining fault verification information for a target battery pair; adjusting the second braking coefficient based on the fault verification information so that the fault verification information corresponding to the target battery pair detected based on the adjusted second braking coefficient meets a predetermined condition; and determining the adjusted second braking coefficient as the target braking coefficient corresponding to the interpolation point.

[0114] According to an embodiment of the present invention, since interpolation relies on historical data, for a target energy storage system with a short-circuit fault, the operating condition information of each battery cell has a certain degree of randomness. In other words, the obtained braking coefficient may be contrary to the real-time change pattern of the battery cell. Therefore, a reverse correction can be performed based on the obtained second braking coefficient.

[0115] For example, the interpolated braking coefficient is 0.95. However, in reality, certain operating conditions, such as the frequency modulation operating conditions of energy storage power stations, have large current fluctuations, and the batteries and connection components heat up quickly, which is more likely to cause leakage and thus short circuits. A stricter target braking coefficient, such as 0.85, is required to effectively identify short-circuit faults.

[0116] Therefore, the fluctuating operating condition can be determined by the variance of the current in the historical period, so that the second braking coefficient corresponding to the operating condition can be adjusted according to the fault verification information.

[0117] According to an embodiment of the present invention, after obtaining the fault verification information for the target battery pair, the correction parameters of the second braking coefficient can be determined based on the fault verification information, and the second braking coefficient can be adjusted using the correction parameters so that the fault verification information corresponding to the target battery pair detected by the adjusted second braking coefficient meets the predetermined conditions, and the adjusted second braking coefficient is determined to be the target braking coefficient corresponding to the interpolation point.

[0118] According to an embodiment of the present invention, the braking coefficient is determined by combining mapping relationship table lookup and interpolation, and the second braking coefficient is reversely iterated and corrected using fault verification information, so that the finally determined target braking coefficient can fine-tune the discrimination threshold to obtain a fault adaptive threshold that is more suitable for the current real-time status of the battery, which is conducive to the real-time detection of short-circuit faults.

[0119] According to an embodiment of the present invention, a battery cell with a negative voltage change in a target battery pair is determined as a faulty cell, and the fault location is determined based on the location of the faulty cell.

[0120] According to an embodiment of the present invention, for a target battery pair, the position between two connected battery cells may be determined as a fault point. After the two target battery pairs are determined, the fault location may be determined based on the two fault points.

[0121] According to an embodiment of the present invention, after the target battery pair is determined by the fault adaptive threshold, the voltage change of the two battery cells of the target battery pair can be determined to locate the short-circuited faulty cell, and based on the locations of multiple faulty cells, the fault location of the target energy storage system can be achieved.

[0122] Figure 4 A block diagram of a device for diagnosing and locating a battery short circuit fault in an energy storage system according to an embodiment of the present invention is shown.

[0123] like Figure 4 As shown, the positioning device 400 includes a collection module 410 , a first obtaining module 420 , a second obtaining module 430 , a first determining module 440 and a second determining module 450 .

[0124] The acquisition module 410 is used to collect the real-time voltage of multiple battery cells in the target energy storage system to obtain the voltage changes of each of the multiple battery cells within adjacent sampling moments;

[0125] A first obtaining module 420 is configured to obtain voltage variation characteristics of each of the plurality of battery pairs according to an absolute value of a difference between voltage variations of two adjacent battery cells in the plurality of battery pairs;

[0126] A second obtaining module 430 is configured to obtain a braking coefficient corresponding to each of the plurality of battery pairs based on the state of charge information, health state information, and operating condition information of each of the plurality of battery cells;

[0127] A first determination module 440 is configured to determine a fault adaptive threshold value for each of the plurality of battery pairs based on the braking coefficients corresponding to the plurality of battery pairs and the absolute value of the sum of voltage changes of two adjacent battery cells in the plurality of battery pairs;

[0128] The second determining module 450 is configured to determine a target battery pair having a short circuit fault from among the multiple battery pairs based on the respective fault adaptive thresholds and voltage variation characteristics of the multiple battery pairs.

[0129] According to an embodiment of the present invention, the second determining module 450 includes a determining submodule.

[0130] The determination submodule is configured to determine, for the nth battery pair, in response to determining that the voltage variation characteristic is greater than a fault adaptive threshold, that the nth battery pair is a target battery pair.

[0131] According to an embodiment of the present invention, the second obtaining module 430 includes a constructing submodule and a determining submodule.

[0132] The construction submodule is used to construct a mapping relationship between historical data and braking coefficient based on the historical data of each of the multiple battery cells, wherein the historical data includes historical state of charge information, historical health status information and historical operating condition information.

[0133] The determination submodule is used to determine the braking coefficient corresponding to each of the multiple battery pairs from the mapping relationship according to the current state of charge information, health status information and operating condition information of each of the multiple battery cells.

[0134] According to an embodiment of the present invention, the determining submodule includes a reading unit and an obtaining unit.

[0135] The reading unit is configured to read a first braking coefficient from a mapping relationship in response to the state of charge information, health state information, and operating condition information of each of the multiple battery cells currently falling into the historical data.

[0136] The obtaining unit is configured to determine corresponding interpolation points from the mapping relationship in response to the current state of charge information, health state information, and operating condition information of each of the multiple battery cells not falling into the historical data, so as to interpolate the interpolation points and obtain a second braking coefficient.

[0137] According to an embodiment of the present invention, the above-mentioned determination device 400 further includes a third determination module and a fourth determination module.

[0138] The third determining module is configured to determine a battery cell with a negative voltage change in the target battery pair as a faulty cell.

[0139] The fourth determining module is used to determine the location where the fault occurs according to the location of the faulty cell.

[0140] Any number of the modules, submodules, units, and subunits according to embodiments of the present invention, or at least part of the functionality of any number of these units, can be implemented in a single module. Any one or more of the modules, submodules, units, and subunits according to embodiments of the present invention can be split into multiple modules for implementation. Any one or more of the modules, submodules, units, and subunits according to embodiments of the present invention can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on a chip, a system on a substrate, a system on a package, an application-specific integrated circuit (ASIC), or can be implemented in hardware or firmware using any other reasonable method of circuit integration or packaging, or can be implemented in any one of the three implementation methods of software, hardware, and firmware, or any appropriate combination of any of these. Alternatively, one or more of the modules, submodules, units, and subunits according to embodiments of the present invention can be at least partially implemented as a computer program module that, when executed, can perform the corresponding functionality.

[0141] For example, any multiple of the acquisition module 410, the first obtaining module 420, the second obtaining module 430, the first determination module 440, and the second determination module 450 may be combined into a single module / unit / sub-unit, or any one of these modules / units / sub-units may be split into multiple modules / units / sub-units. Alternatively, at least part of the functionality of one or more of these modules / units / sub-units may be combined with at least part of the functionality of other modules / units / sub-units and implemented in a single module / unit / sub-unit. According to an embodiment of the present invention, at least one of the acquisition module 410, the first obtaining module 420, the second obtaining module 430, the first determination module 440, and the second determination module 450 may be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on a chip, a system on a substrate, a system on a package, an application specific integrated circuit (ASIC), or may be implemented in hardware or firmware through any other reasonable means of circuit integration or packaging, or implemented in any one of software, hardware, and firmware, or any suitable combination thereof. Alternatively, at least one of the acquisition module 410, the first obtaining module 420, the second obtaining module 430, the first determination module 440 and the second determination module 450 can be at least partially implemented as a computer program module, which can perform corresponding functions when executed.

[0142] It should be noted that the portion of the device for diagnosing and locating a battery short-circuit fault in an energy storage system in the embodiments of the present invention corresponds to the portion of the method for diagnosing and locating a battery short-circuit fault in an energy storage system in the embodiments of the present invention. For a description of the device for diagnosing and locating a battery short-circuit fault in an energy storage system, specific reference is made to the portion of the method for diagnosing and locating a battery short-circuit fault in an energy storage system, which will not be repeated here.

[0143] Figure 5 A block diagram of an electronic device suitable for implementing a method for diagnosing and locating a battery short circuit fault in an energy storage system according to an embodiment of the present invention is shown.

[0144] Figure 5 The electronic device shown is only an example and should not limit the functions and scope of use of the embodiments of the present invention.

[0145] like Figure 5As shown, an electronic device 500 according to an embodiment of the present invention includes a processor 501, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 502 or a program loaded from a storage unit 508 into a random access memory (RAM) 503. The processor 501 may include, for example, a general-purpose microprocessor (e.g., a CPU), an instruction set processor and / or a related chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor 501 may also include onboard memory for caching purposes. The processor 501 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of the present invention.

[0146] The RAM 503 stores various programs and data required for the operation of the electronic device 500. The processor 501, ROM 502, and RAM 503 are interconnected via a bus 504. The processor 501 executes the programs in the ROM 502 and / or RAM 503 to perform the various operations of the method flow according to the embodiment of the present invention. It should be noted that the above-mentioned programs may also be stored in one or more memories other than the ROM 502 and RAM 503. The processor 501 may also execute the various operations of the method flow according to the embodiment of the present invention by executing the programs stored in the one or more memories.

[0147] According to an embodiment of the present invention, electronic device 500 may further include an input / output (I / O) interface 505, which is also connected to bus 504. Electronic device 500 may also include one or more of the following components connected to I / O interface 505: an input section 506 including a keyboard, mouse, etc.; an output section 507 including devices such as a cathode ray tube (CRT), liquid crystal display (LCD), and speakers; a storage section 508 including a hard disk; and a communication section 509 including a network interface card such as a LAN card or modem. Communication section 509 performs communication processing via a network such as the Internet. A drive 510 is also connected to I / O interface 505 as needed. Removable media 511, such as a magnetic disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed in drive 510 as needed, so that computer programs read from the removable media can be installed into storage section 508 as needed.

[0148] According to an embodiment of the present invention, the method flow according to an embodiment of the present invention can be implemented as a computer software program. For example, an embodiment of the present invention includes a computer program product, which includes a computer program carried on a computer-readable storage medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 509, and / or installed from the removable medium 511. When the computer program is executed by the processor 501, the above-mentioned functions defined in the system of the embodiment of the present invention are executed. According to an embodiment of the present invention, the system, device, apparatus, module, unit, etc. described above can be implemented by a computer program module.

[0149] The present invention also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments, or may exist independently and not incorporated into the device / apparatus / system. The computer-readable storage medium carries one or more programs, which, when executed, implement the method according to the embodiments of the present invention.

[0150] According to embodiments of the present invention, a computer-readable storage medium may be a non-volatile computer-readable storage medium. Examples include, but are not limited to, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present invention, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0151] For example, according to an embodiment of the present invention, the computer-readable storage medium may include the ROM 502 and / or the RAM 503 described above and / or one or more memories other than the ROM 502 and the RAM 503 .

[0152] An embodiment of the present invention also includes a computer program product, which includes a computer program, which contains program code for executing the method provided by the embodiment of the present invention. When the computer program product is run on an electronic device, the program code is used to enable the electronic device to implement the method for locating a battery short circuit fault in an energy storage system provided by the embodiment of the present invention.

[0153] When the computer program is executed by the processor 501, the above functions defined in the system / device of the embodiment of the present invention are performed. According to the embodiment of the present invention, the system, device, module, unit, etc. described above can be implemented by a computer program module.

[0154] In one embodiment, the computer program may be stored on a tangible storage medium such as an optical storage device or a magnetic storage device. In another embodiment, the computer program may be transmitted and distributed in the form of a signal on a network medium, downloaded and installed via the communication portion 509, and / or installed from a removable medium 511. The program code contained in the computer program may be transmitted using any appropriate network medium, including but not limited to wireless, wired, or any suitable combination thereof.

[0155] According to an embodiment of the present invention, the program code for executing the computer program provided by the embodiment of the present invention can be written in any combination of one or more programming languages. Specifically, these computer programs can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages include, but are not limited to, languages such as Java, C++, Python, "C" or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (for example, using an Internet service provider to connect via the Internet).

[0156] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of the systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each box in the flowchart or block diagram may represent a module, program segment, or portion of code, which contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the boxes may occur in an order different from that marked in the accompanying drawings. For example, two boxes shown in succession may actually be executed substantially in parallel, or they may sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, as well as the combination of boxes in the block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or may be implemented using a combination of dedicated hardware and computer instructions. It will be understood by those skilled in the art that the features described in the various embodiments of the present invention may be combined and / or coupled in various ways, even if such combinations or couplings are not explicitly described in the present invention. In particular, the features described in the various embodiments of the present invention may be combined and / or coupled 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.

[0157] The above describes embodiments of the present invention. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Although each embodiment has been described separately above, this does not mean that the measures in each embodiment cannot be advantageously used in combination. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A method for diagnosing and locating a battery short circuit fault in an energy storage system, characterized in that: include: Performing real-time voltage acquisition on multiple battery cells in a target energy storage system to obtain voltage changes of each of the multiple battery cells within adjacent sampling moments; Obtaining voltage variation characteristics of each of the plurality of battery pairs according to an absolute value of a difference between the voltage variations of two adjacent battery cells in the plurality of battery pairs; Obtaining a braking coefficient corresponding to each of the plurality of battery pairs based on state of charge information, health status information, and operating condition information of each of the plurality of battery cells; determining a fault adaptive threshold for each of the plurality of battery pairs according to the braking coefficient corresponding to each of the plurality of battery pairs and an absolute value of the sum of the voltage changes of two adjacent battery cells in the plurality of battery pairs; A target battery pair in which a short circuit fault has occurred is determined from the plurality of battery pairs based on the respective fault adaptive thresholds and voltage variation characteristics of the plurality of battery pairs.

2. The diagnosis and positioning method according to claim 1, characterized in that: The number of the plurality of battery pairs is N; and determining a target battery pair having a short circuit fault from the plurality of battery pairs based on respective fault adaptive thresholds and voltage variation characteristics of the plurality of battery pairs includes: For an nth battery pair, in response to determining that the voltage variation characteristic is greater than the fault adaptive threshold, the nth battery pair is determined to be the target battery pair, where n∈N and n and N are positive integers.

3. The diagnosis and positioning method according to claim 1, characterized in that: The obtaining of the braking coefficient corresponding to each of the plurality of battery pairs based on the state of charge information, health state information, and operating condition information of each of the plurality of battery cells includes: Based on the historical data of each of the plurality of battery cells, a mapping relationship between the historical data and the braking coefficient is constructed, wherein the historical data includes historical state of charge information, historical health status information, and historical operating condition information; According to the current state of charge information, the health state information, and the operating condition information of each of the multiple battery cells, a braking coefficient corresponding to each of the multiple battery pairs is determined from the mapping relationship.

4. The diagnosis and positioning method according to claim 3, characterized in that: The determining, from the mapping relationship, the braking coefficient corresponding to each of the plurality of battery pairs according to the current state of charge information, the health state information, and the operating condition information of each of the plurality of battery cells includes: In response to the state of charge information, the health state information, and the operating condition information of each of the plurality of battery cells currently falling within the historical data, reading a first braking coefficient from the mapping relationship; In response to the state of charge information, the health status information, and the operating condition information of each of the multiple battery cells currently not falling into the historical data, a corresponding interpolation point is determined from the mapping relationship to interpolate the interpolation point to obtain a second braking coefficient.

5. The diagnosis and positioning method according to claim 4, characterized in that: The determining of the corresponding interpolation point from the mapping relationship to interpolate the interpolation point to obtain the second braking coefficient further includes: Acquiring fault verification information for the target battery pair; adjusting the second braking coefficient based on the fault verification information so that the fault verification information corresponding to the target battery pair detected based on the adjusted second braking coefficient meets a predetermined condition; The adjusted second braking coefficient is determined as the target braking coefficient corresponding to the interpolation point.

6. The diagnosis and positioning method according to claim 1, characterized in that: The diagnosis and positioning method further includes determining the battery cell in the target battery pair whose voltage variation is negative as a faulty cell.

7. The diagnosis and positioning method according to claim 6, characterized in that: The diagnosis and positioning method further includes: determining the location where the fault occurs based on the location of the faulty cell.

8. The diagnosis and positioning method according to claim 1, characterized in that: Two adjacent battery cells in the battery pair belong to the same battery cluster.

9. A device for diagnosing and locating battery short circuit faults in an energy storage system, characterized in that: include: An acquisition module is used to acquire the voltage of multiple battery cells in the target energy storage system in real time, and obtain the voltage change of each of the multiple battery cells within adjacent sampling moments; a first obtaining module, configured to obtain voltage variation characteristics of each of the plurality of battery pairs according to an absolute value of a difference between the voltage variation amounts of two adjacent battery cells in the plurality of battery pairs; a second obtaining module, configured to obtain a braking coefficient corresponding to each of the plurality of battery pairs based on the state of charge information, health state information, and operating condition information of each of the plurality of battery cells; a first determining module, configured to determine a fault adaptive threshold value for each of the plurality of battery pairs according to the braking coefficient corresponding to each of the plurality of battery pairs and an absolute value of the sum of the voltage changes of two adjacent battery cells in the plurality of battery pairs; The second determining module is configured to determine a target battery pair having a short circuit fault from the plurality of battery pairs based on respective fault adaptive thresholds and voltage variation characteristics of the plurality of battery pairs.

10. An electronic device comprising: one or more processors; 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 implement the diagnosis and positioning method according to any one of claims 1 to 8.

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