Thermal runaway warning method, device and equipment for lithium battery of energy storage power station

Abstract

The present invention provides a method, device and equipment for early warning of thermal runaway of lithium batteries in an energy storage power station, which are applied to the technical field of lithium battery safety in an energy storage power station. The method for early warning of thermal runaway of lithium batteries in the energy storage power station includes: obtaining the charging current and charging voltage at each moment during the constant current charging process of the target lithium battery; in response to determining that the charging voltage continuously decreases at adjacent moments within the target period, processing the multiple charging currents and multiple charging voltages at multiple moments within the target period to generate energy change information of the target lithium battery within the target period; and in response to the energy change information being greater than the target threshold, sending an early warning message of thermal runaway of the target lithium battery to the terminal; wherein, the target threshold is dynamically configured according to the voltage change information and the predetermined charging current after standing when the target lithium battery is charged at a predetermined constant current to a predetermined state of charge under normal operating conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery safety in energy storage power stations, and particularly to a method, device and equipment for predicting thermal runaway of lithium batteries in energy storage power stations. Background Art

[0002] Clean energy represented by wind power and photovoltaic power has intermittency and volatility, and energy storage systems are required to achieve power peak regulation and smooth output of electric energy. Due to the limitations of terrain or cost constraints of traditional energy storage methods (such as pumped-storage energy storage, compressed air energy storage, etc.), lithium battery energy storage power stations have become the best choice due to their advantages such as rapidity, high energy density, and long life. However, the protection facilities of lithium battery energy storage power stations are not perfect, resulting in frequent safety accidents in lithium battery energy storage power stations, and even accidents such as fires and explosions, which seriously endanger life and property safety.

[0003] At present, the thermal runaway warning of lithium batteries in energy storage power stations is mainly achieved through the Battery Management System (BMS). The main method is to judge whether the voltage / current of the lithium battery exceeds the set safety threshold to achieve thermal runaway protection. However, voltage / current fluctuations may be caused by various factors (such as battery aging, poor contact or real thermal runaway). The single information dimension not only has strong hysteresis but also has a high false alarm rate, and it is difficult to achieve efficient warning of thermal runaway of lithium batteries in energy storage power stations. Summary of the Invention

[0004] In view of this, the present invention provides a method, device and equipment for predicting thermal runaway of lithium batteries in energy storage power stations.

[0005] The first aspect of the present invention provides a method for predicting thermal runaway of lithium batteries in energy storage power stations, which specifically includes: obtaining the charging current and charging voltage at each moment during the constant current charging process of the target lithium battery; in response to determining that the charging voltage continuously decreases at adjacent moments within the target period, processing the multiple charging currents and multiple charging voltages at multiple moments within the target period to generate energy change information of the target lithium battery within the target period; in response to the energy change information being greater than the target threshold, sending a thermal runaway warning information for the target lithium battery to the terminal; wherein, the target threshold is dynamically configured according to the voltage change information and the predetermined charging current after the target lithium battery is charged to the predetermined charge load at a predetermined constant current in the normal operation state.

[0006] The second aspect of the present invention provides a thermal runaway warning device for lithium batteries in an energy storage power station, including an acquisition module, a processing module, and a sending module. The acquisition module is used to acquire the charging current and charging voltage at each moment during the constant current charging process of the target lithium battery. The processing module is used to, in response to determining that the charging voltage continuously decreases at adjacent moments within the target period, process the multiple charging currents and multiple charging voltages at multiple moments within the target period to generate energy change information of the target lithium battery within the target period. The sending module is used to, in response to the energy change information being greater than the target threshold, send a thermal runaway warning message for the target lithium battery to the terminal; wherein the target threshold is dynamically configured according to the voltage change information and the predetermined charging current after the target lithium battery is left standing when it is charged at a predetermined constant current to a predetermined state of charge in the normal operating state.

[0007] The third aspect of the present invention provides an electronic device, including: 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 method as described above.

[0008] The fourth aspect of the present invention provides a computer-readable storage medium storing executable instructions, which when executed by a processor cause the processor to implement the method as described above.

[0009] The fifth aspect of the present invention provides a computer program product including a computer program, which when executed by a processor implements the method as described above.

[0010] According to an embodiment of the present invention, the characteristic that the charging voltage of the lithium battery in the energy storage power station continuously decreases during the constant current charging process is used as a trigger condition, the multiple charging voltages and charging currents within the period when the charging voltage continuously decreases are processed to generate energy change information, and whether to issue a thermal runaway warning is determined based on the energy change information. The principle of this thermal runaway warning method for lithium batteries in the energy storage power station is simple and the operation speed is fast. Since the energy change information accumulated within the period when the charging voltage continuously decreases is used to judge whether the thermal runaway warning threshold is reached, it can avoid misoperation caused by signal fluctuations and current fluctuations. In addition, since the target threshold is dynamically configured according to the voltage change after standing and the predetermined charging current when the target lithium battery is charged at a predetermined constant current to a predetermined state of charge in the normal operating state, the target threshold can be updated according to the change of the electrical characteristics of the target lithium battery during operation, so as to achieve the technical effect of adaptively configuring the threshold according to the electrical characteristics of the battery, further improving the warning accuracy of thermal runaway of lithium batteries in the energy storage power station and ensuring the safe and stable operation of the energy storage power station. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Through the following description of the embodiments of the present invention with reference to the accompanying drawings, the above and other objects, features, and advantages of the present invention will become clearer. In the drawings:

[0012] Figure 1 Shows an application scenario diagram of the thermal runaway warning method for lithium batteries in an energy storage power station according to an embodiment of the present invention;

[0013] Figure 2 Shows a flowchart of the thermal runaway warning method for lithium batteries in an energy storage power station according to an embodiment of the present invention;

[0014] Figure 3A Shows an equivalent circuit model diagram of a lithium battery in an energy storage power station before thermal runaway;

[0015] Figure 3B Shows a voltage-current schematic diagram of a lithium battery in an energy storage power station before thermal runaway;

[0016] Figure 3C Shows an equivalent circuit model diagram of a lithium battery in an energy storage power station during charging;

[0017] Figure 4 Shows a schematic diagram of the principle of the lithium battery warning method in an energy storage power station according to an embodiment of the present invention;

[0018] Figure 5 Shows a structural block diagram of the thermal runaway warning device for lithium batteries in an energy storage power station according to an embodiment of the present invention;

[0019] Figure 6 Shows a block diagram of an electronic device suitable for implementing the thermal runaway warning method for lithium batteries in an energy storage power station. Detailed implementation manners

[0020] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In the following detailed description, for the sake of explanation, many specific details are set forth in order to provide a comprehensive understanding of the embodiments of the present invention. However, obviously, one or more embodiments can also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0021] The terms used herein are merely for describing specific embodiments and are not intended to limit the present invention. The terms "including", "comprising", etc. used herein indicate the presence of the described features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components. [[ID=4,2]]

[0022] 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.

[0023] In cases where expressions similar to "at least one of A, B, and C, etc." are used, generally, it should be interpreted according to 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 not be limited to, a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0024] In the prior art, an energy storage power station uses a BMS system to perform early warning of thermal runaway of lithium batteries, and it mainly judges by whether the voltage and current exceed the set safety threshold. However, in actual situations, due to the influence of battery aging or the external environment, it is difficult to effectively give an early warning of impending thermal runaway by simply monitoring the voltage and current of a single lithium battery cell.

[0025] In view of this, embodiments of the present invention provide a method for early warning of thermal runaway of lithium batteries in an energy storage power station. Using the characteristic that the charging voltage continuously decreases during the constant current charging process as a trigger condition, multiple charging voltages and charging currents during the period when the charging voltage continuously decreases are processed to generate energy change information, and based on the energy change information, it is determined whether to give an early warning of thermal runaway. This method has a simple principle and a fast operation speed, can avoid misoperations caused by signal fluctuations and current fluctuations, and improve the accuracy of early warning of thermal runaway of lithium batteries.

[0026] Figure 1 The application scenario diagram of the method for early warning of thermal runaway of lithium batteries in an energy storage power station according to an embodiment of the present invention is shown.

[0027] As Figure 1 shown, the application scenario 100 according to this embodiment may include a first terminal device 101, a second terminal device 102, a network 103, and a server 104. The network 103 is used to provide a medium for communication links between the first terminal device 101, the second terminal device 102, and the server 104. The network 103 may include various connection types, such as wired, wireless communication links, or fiber optic cables, etc.

[0028] The first terminal device 101 can be used to collect the charging current of the target lithium battery at each moment during the constant current charging process. The second terminal device 102 can be used to collect the charging voltage of the target lithium battery at each moment during the constant current charging process.

[0029] Server 104 can be a server that provides various services. For example, it can be a background management server (only for example) that supports the websites browsed by the user using the first terminal device 101 and the second terminal device 102. The background management server can analyze and process the obtained charging current and charging voltage data, and feedback the processing results (such as web pages, information, or data obtained or generated according to user requests, etc.) to the terminal device.

[0030] It should be noted that the energy storage power station lithium battery thermal runaway warning method provided by the embodiments of the present invention can generally be executed by server 104. Correspondingly, the energy storage power station lithium battery thermal runaway warning device provided by the embodiments of the present invention can generally be set in server for 104. The energy storage power station lithium battery thermal runaway warning method provided by the embodiments of the present invention can also be executed by a server or a server cluster different from server 104 and capable of communicating with the first terminal device 101, the second terminal device 102, and / or server 104. Correspondingly, the energy storage power station lithium battery thermal runaway warning device provided by the embodiments of the present invention can also be set in a server or a server cluster different from server 104 and capable of communicating with the first terminal device 101, the second terminal device 102, and / or server 104.

[0031] It should be understood that Figure 1 the numbers of terminal devices, networks, and servers in

[0032] are merely illustrative. According to the implementation requirements, there can be any number of terminal devices, networks, and servers. Figure 1 are merely illustrative. According to the implementation requirements, there can be any number of terminal devices, networks, and servers. Figures 2 to 6 Based on the scenario described below, the energy storage power station lithium battery thermal runaway warning method of the embodiments of the present invention will be described in detail through

[0033] Figure 2 shows a flowchart of the energy storage power station lithium battery thermal runaway warning method of the embodiments of the present invention.

[0034] Embodiments of the present invention provide an energy storage power station lithium battery thermal runaway warning method, as Figure 2 shown, including the following operations S210 to operation S230:

[0035] Operation S210: Obtain the charging current at each moment and the charging voltage at each moment during the constant current charging process of the target lithium battery.

[0036] Operation S220: In response to determining that the charging voltage continuously decreases at adjacent moments within the target period, process the multiple charging currents and multiple charging voltages at multiple moments within the target period to generate energy change information of the target lithium battery within the target period.

[0037] Operation S230: In response to the energy change information being greater than the target threshold, send a thermal runaway warning message for the target lithium battery to the terminal.

[0038] According to an embodiment of the present invention, a large number of lithium battery cells, which depends on the total capacity of the energy storage power station, the specifications (capacity, voltage, etc.) of the lithium battery cells, and the integration method, are included in the energy storage power station. The lithium battery cells in the energy storage power station achieve the energy storage requirement through series / parallel combinations. The target lithium battery in this embodiment is each lithium battery cell in the energy storage power station. During the constant current charging process of the lithium battery cell, the energy charged into the lithium battery is consumed by the internal resistance and polarization effect, and the rest is converted into the open-circuit voltage of the lithium battery. When the charging current is constant, due to the increase in the open-circuit voltage, the charging voltage of the lithium battery also keeps increasing. Therefore, during normal charging of the lithium battery, the characteristic of the charging voltage rising should be maintained.

[0039] Figure 3A The charging equivalent circuit model diagram of the lithium battery in the energy storage power station before thermal runaway according to the embodiment of the present invention is shown.

[0040] As Figure 3A shown, the power supply is a constant current source, indicating that the lithium battery is in a constant current charging state. is the equivalent internal short-circuit resistance before thermal runaway, is the short-circuit current of the lithium battery before thermal runaway, is the internal resistance of the lithium battery, 、 represent the polarization characteristics of the lithium battery, is the open-circuit voltage of the lithium battery, is the open-circuit current of the lithium battery. Under normal circumstances, the energy input into the lithium battery is consumed by the internal resistance, and the rest is converted into the electric potential energy of the lithium battery, that is, increases, then the terminal voltage of the lithium battery also keeps increasing. Therefore, during the normal constant current charging process of the lithium battery, the charging voltage should keep rising.

[0041] Figure 3B The voltage-current schematic diagram of the lithium battery in the energy storage power station before thermal runaway according to the embodiment of the present invention is shown.

[0042] As Figure 3B shown, before the lithium battery undergoes thermal runaway, due to the additional consumption caused by the equivalent internal short-circuit resistance the charging voltage of the lithium battery in the constant current charging condition shows a situation of not rising but falling.

[0043] In a specific embodiment, during the constant current charging process of the lithium battery in the energy storage power station, according to the above-mentioned characteristic that the charging voltage does not rise but falls, the following trigger condition can be set, that is, to judge whether there is the following formula (1):

[0044] (1)

[0045] In formula (1), is the charging voltage at time t, is the charging voltage at time t-1, is the charging current at time t, is the charging voltage drop at time t with respect to time t-1.

[0046] In a specific embodiment, separately monitoring the charging voltage and charging current of a single lithium battery cell will be affected by the working state of the battery in actual applications, making it difficult to achieve efficient early warning of an impending thermal runaway lithium battery. Therefore, in the embodiment of the present invention, after obtaining the target time period during which the charging voltage continuously decreases, the charging voltage and charging current within the target time period are processed to obtain the energy change information of the single lithium battery cell.

[0047] Due to the increase in the number of lithium battery cycles and the influence of the external environment, the battery state will change with the aging of the battery and the change of the working environment, and the target threshold needs to be dynamically adjusted accordingly. Therefore, in the embodiment of the present invention, the maximum misoperation amount can be calculated based on the voltage change information and the predetermined charging current after standing when the target lithium battery is charged at a predetermined constant current to a predetermined state of charge in a normal operating state. The maximum misoperation amount represents the maximum cumulative amount of energy change that does not trigger the thermal runaway state due to signal fluctuations, and the maximum misoperation amount is dynamically configured as the target threshold.

[0048] Since the target threshold is dynamically configured based on the voltage change and the predetermined charging current after standing when the target lithium battery is charged at a predetermined constant current to a predetermined state of charge in a normal operating state, the target threshold can be updated according to the change of the electrical characteristics of the target lithium battery during operation, so as to achieve the technical effect of adaptively configuring the threshold according to the electrical characteristics of the battery. Among them, the state of charge refers to the capacitance of the lithium battery, that is, the state of charge, indicating that the target lithium battery is charged to a predetermined battery capacity at a predetermined constant current. This means that the method provided by the embodiment of the present invention can adaptively update the threshold according to the battery capacity and the attenuation state, thereby further reducing the probability of false early warning.

[0049] According to an embodiment of the present invention, by utilizing the voltage change characteristics of the lithium-ion batteries in an energy storage power station under a constant-current charging condition, a rapid warning of an impending thermally runaway lithium-ion battery is achieved. The characteristic that the voltage of the lithium-ion batteries in the energy storage power station continuously decreases during the constant-current charging process is set as the triggering condition for thermally runaway warning; the voltage and current of the target lithium-ion battery cell that meet the triggering condition for thermally runaway warning are continuously collected, and multiple charging voltages and charging currents within a target time period are processed to generate energy change information; when the energy change information exceeds the set target threshold, a thermally runaway warning is issued. In the thermally runaway warning method for the lithium-ion batteries in the energy storage power station according to the embodiment of the present invention, since it is judged whether the thermally runaway warning threshold is reached based on the energy change information accumulated during the period when the charging voltage continuously decreases, it can avoid misoperation caused by signal fluctuations and current fluctuations, further improve the warning accuracy of the thermally runaway of the lithium-ion batteries in the energy storage power station, and ensure the safe and stable operation of the energy storage power station.

[0050] In an embodiment of the present invention, in the above method, the target time period is T moments, where T is an integer greater than 1; in response to determining that the charging voltages at adjacent moments within the target time period continuously decrease, multiple charging currents and multiple charging voltages at multiple moments within the target time period are processed to generate energy change information of the target lithium-ion battery within the target time period, including: processing the charging voltage at the (t - 1)th moment, the charging voltage at the tth moment, and the charging current at the tth moment to generate energy change information of the (t - 1)th period, where t = 2, 3,..., T; and generating energy change information within the target time period according to the energy change information of (T - 1) periods.

[0051] For example: when it is collected that the charging voltages at adjacent moments within the target time period continuously decrease, that is, when the triggering warning condition is met, the energy input into the lithium-ion battery under the constant-current charging condition is:

[0052] (2)

[0053] In formula (2), is the charging voltage of the lithium-ion battery, is the charging current of the lithium-ion battery, is the charging time.

[0054] It can be seen from formula (2) that the energy change information of the lithium-ion battery within the target time period is:

[0055] (3)

[0056] In formula (3), is the change amount of the charging voltage within the target time period , is the charging current of the lithium-ion battery.

[0057] According to an embodiment of the present invention, the product of the change in charging voltage, charging current, and the change in time until a warning is triggered is used as energy change information to reflect the real-time energy changes of lithium batteries in energy storage power stations. Before a lithium battery experiences thermal runaway, the current may increase abnormally while the voltage may decrease, resulting in energy changes. This energy change may be more sensitive than monitoring voltage or current alone. This is especially true during internal short circuits, when current increases and voltage decreases, leading to abnormal energy changes. This method can improve the sensitivity of warnings. Furthermore, this method is computationally simple, highly real-time, and does not require complex models, making it suitable for real-time monitoring.

[0058] In an embodiment of the present invention, the method generates energy change information within a target period based on energy change information in T-1 periods, including: integrating the energy change information in T-1 periods to generate energy change information within the target period.

[0059] For example: It is known that the charging voltage of a lithium battery continues to decrease before thermal runaway. The accumulation of is used as the characteristic quantity of thermal runaway warning. The longer the duration of abnormal energy change, the greater the continuously accumulated energy change information, indicating that the risk of thermal runaway is greater. The energy change information within the target period is set. Energy change information The integral of is as follows (4):

[0060] (4)

[0061] In formula (4), is the energy change information within the target period after integration, When the trigger condition is met, For the moment when the trigger condition is not met, is the charging voltage drop of the lithium battery during the target period, is the charging current of the lithium battery. Discretizing Equation (4) yields Equation (5):

[0062] (5)

[0063] In formula (5), is the energy change information within the target period after integration, , n=1,2,3,…,N, The moment when the trigger condition (1) is satisfied is: For the moment when the trigger condition is not met, For the target period, is the change in charging voltage of the lithium battery during the target period, is the charging current of the lithium battery.

[0064] According to an embodiment of the present invention, the above energy change information is integrated to further generate energy change information within a target period. The energy change information after integration can improve the accuracy of lithium battery thermal runaway warning. The accumulation of integration can smooth out instantaneous fluctuations, capture long-term change trends, and help detect slowly developing internal short circuits or aging problems. In addition, the integration of energy changes can reflect the total energy change within a period of time, amplify the thermal runaway characteristics of lithium batteries, and trigger warnings more effectively than individual instantaneous values.

[0065] In an embodiment of the present invention, the above method further includes: obtaining voltage change information and a predetermined charging current after standing when the target lithium battery is charged at a predetermined constant current to a predetermined state of charge under normal operating conditions; and processing the predetermined charging current and multiple voltage change information within a predetermined period to generate a target threshold.

[0066] For example: after setting the method for generating energy change information within the target period of the lithium battery, a certain target threshold needs to be set to determine whether thermal runaway is about to occur. The setting requirements of the target threshold need to ensure that false warnings do not occur during normal battery operation. It is known that for a normal battery in a constant current charging state, if the charging current value decreases, the charging voltage will also decrease, and energy change information will also be generated , so the maximum target threshold in the above state needs to be calculated .

[0067] Figure 3C Fig. shows the circuit equivalent model diagram of the lithium battery in the energy storage power station according to the embodiment of the present invention.

[0068] As Figure 3C shown, the power supply is a constant current source, indicating that the battery is in a constant current charging state. is the internal resistance of the lithium battery, , represent the polarization characteristics of the lithium battery, is the terminal voltage of the RC circuit, is the open circuit voltage of the lithium battery.

[0069] Assume that the lithium battery is in a constant current charging state, that is, the predetermined charging current remains unchanged, and the charging circuit is in a stable state. Then Figure 3C in the RC circuit, the capacitor C branch can be regarded as an open circuit, and the relationship between the components in the battery charging circuit is: [[ID=Z39]]

[0070] (6)

[0071] In formula (6), is the steady-state charging voltage of the lithium battery during constant current charging, is the steady-state open circuit voltage of the lithium battery, Pre-determined charging current for the lithium battery Polarization voltage of the lithium battery at steady state

[0072] If the current suddenly decreases at this time , assuming that during the current change process, the parameters of the lithium battery , , , remain unchanged, then the charging voltage of the lithium battery after the current change is:

[0073] (7)

[0074] In Equation (7), is the charging voltage of the lithium battery after the current change, is the open-circuit voltage of the lithium battery after the current change, is the pre-determined charging current for the lithium battery, is the polarization voltage of the lithium battery after the current change

[0075] Therefore, the change in the charging voltage caused by the decrease in the charging current of the lithium battery is:

[0076] (8)

[0077] In Equation (8), is the change in the charging voltage caused by the decrease in the charging current of the lithium battery, is the electric potential energy stored in the battery due to energy input within the pre-determined time period dt, which is related to the current within the pre-determined time period dt

[0078] It can be calculated through Equation (4) and Equation (8) that the energy change information generated by the sudden decrease in the current is:

[0079] (9)

[0080] In Equation (9) is the energy change information generated by the decrease in the charging current of the lithium battery

[0081] Taking as the charging resistance of the battery open-circuit voltage , representing the ratio of the change in the battery open-circuit voltage varying with the charging current is a fixed constant related to the battery. Therefore, it is known that the value range of , as can be seen from Equation (9), when , , , and t are constants, taking , obtains the maximum value. Substituting into Equation (9) gives:

[0082] (10)

[0083] Let in Equation (8), then Equation (8) can be written as:

[0084] (11)

[0085] Substituting Equation (11) into Equation (10) gives:

[0086] (12)

[0087] In Equation (12), is the predetermined constant current charging current of the energy storage power station battery, is the charging voltage change amount after the battery is suddenly static when charging at the predetermined charging current with constant current.

[0088] The maximum value of is the maximum target threshold and , are positively correlated. The maximum value of is the predetermined charging current value of the lithium battery of the energy storage power station. The maximum value of

[0089] is the charging voltage change value after the lithium battery of the energy storage power station is charged to the full charge state (i.e., SOC = 100%) with the maximum constant current and then suddenly static. Therefore, the maximum target threshold

[0090] In Equation (13), is the maximum predetermined charging current of the energy storage power station battery, is the charging voltage change amount after the battery is suddenly static when charging with the current with constant current.

[0091] According to an embodiment of the present invention, after collecting the energy change information during the target period, a target threshold needs to be set to determine the occurrence of thermal runaway. The setting of the target threshold needs to avoid false warnings during the normal operation of the battery. The target threshold can be set based on the maximum charging current and voltage change of the lithium battery, ensuring that false alarms do not occur under normal conditions, and achieving accurate early warning of thermal runaway faults. The dynamic threshold can automatically adjust the judgment criteria according to the real-time working state of the battery, avoiding false warnings and false alarms of aging batteries, and improving the effectiveness of early warning.

[0092] In an embodiment of the present invention, in the above method, processing the predetermined charging current and multiple voltage change information within a predetermined period to generate a target threshold includes: processing the predetermined charging current and multiple voltage change information within a predetermined period to generate allowed energy change information; and generating a target threshold based on a predetermined coefficient and the allowed energy change information.

[0093] For example: obtained from Equation (13) is the maximum energy change information that the lithium battery of the energy storage power station will generate under normal conditions, and judge the energy change information calculated by Equation (4) whether it is greater than the set target threshold, that is, judge whether the following Equation (14) holds.

[0094] (14)

[0095] In Equation (14), is a predetermined coefficient to prevent false diagnosis caused by signal fluctuations, and can take 1.1 - 1.3.

[0096] According to an embodiment of the present invention, the predetermined coefficient is used as a correction factor for the dynamic threshold, and suppresses the interference of signal fluctuations through weighted calculation. The predetermined coefficient is a parameter used to ensure that the target threshold is neither too sensitive nor too loose during the dynamic adjustment process, and is used to balance the sensitivity and false alarm rate.

[0097] In an embodiment of the present invention, the above method further includes: in response to not receiving feedback information from the terminal for the thermal runaway warning information within a predetermined period, sending a control instruction to the circuit breaker connected to the target lithium battery in the energy storage power station to isolate the target lithium battery from the battery pack operating normally in the energy storage power station.

[0098] In a specific embodiment, if the above Equation (14) holds, a thermal runaway warning of the lithium battery is issued, the circuit breaker of the energy storage power station is timely disconnected, and the battery about to undergo thermal runaway is repaired, isolated and replaced.

[0099] According to an embodiment of the present invention, after a thermal runaway warning of a lithium battery in an energy storage power station and without receiving feedback information from the terminal for this warning, the circuit breaker connected to the lithium battery can be quickly controlled to act, and the rapid cut-off action through the feedback mechanism can prevent current from continuing to flow into the target lithium battery, reduce energy release, and thus reduce the probability of thermal runaway occurrence.

[0100] Figure 4 The schematic diagram of the principle of the lithium battery warning method for an energy storage power station according to an embodiment of the present invention is shown.

[0101] As Figure 4 shown, in Embodiment 400, the warning method is described through the following operations S410~S480.

[0102] In operation S410, the charging voltage and charging current of each battery cell at each moment are collected. At this time, the energy change information F0 = 0 under the normal constant current charging state.

[0103] In operation S420, the difference between the charging voltage and current at adjacent moments is calculated.

[0104] In operation S430, it is judged whether the warning condition for lithium battery thermal runaway is triggered. This operation is to judge whether the above formula (1) is satisfied. If the warning condition for lithium battery thermal runaway is not triggered, return to execute operation S420; if the warning condition for lithium battery thermal runaway is triggered, continue to execute operation S440.

[0105] In operation S440, continue to judge the change of the charging current in the target period. If the current shows a decreasing characteristic, return to execute operation S420; if the current does not show a decreasing characteristic, continue to execute operation S450.

[0106] In operation S450, the energy change information in the target period is calculated. This operation is to calculate the energy change information in the target period using formula (3).

[0107] In operation S460, the energy change information is generated through integral processing. This operation is to calculate the energy change information through formulas (4) and (5).

[0108] In operation S470, it is judged whether the energy change information is less than the set target threshold. If the energy change information is less than the set target threshold, it is determined that the lithium battery has no thermal runaway risk, and return to execute operation S420; if the energy change information is greater than the set target threshold, continue to execute operation S480.

[0109] In operation S480, an internal short circuit fault occurs in the lithium battery, and there is a risk of thermal runaway. At this time, the circuit breaker connected to the lithium battery needs to be disconnected, and the battery about to have thermal runaway needs to be repaired, isolated and replaced.

[0110] Another aspect of the present invention provides a thermal runaway warning device for lithium batteries in an energy storage power station, which will be described in detail below in conjunction with Figure 5 this device.

[0111] Figure 5 The structural block diagram of the thermal runaway warning device for lithium batteries in an energy storage power station according to an embodiment of the present invention is shown.

[0112] As Figure 5 shown, the thermal runaway warning device 500 for lithium batteries in this embodiment includes an acquisition module 510, a processing module 520, and a sending module 530.

[0113] The acquisition module 510 is configured to acquire the charging current and the charging voltage at each moment during the constant current charging process of the target lithium battery. In one embodiment, the acquisition module 510 can be used to perform the operation S210 described above, which will not be elaborated here.

[0114] The processing module 520 is configured to process the multiple charging currents and multiple charging voltages at multiple moments in the target period in response to determining that the charging voltage continuously decreases at adjacent moments in the target period, and generate energy change information of the target lithium battery in the target period. In one embodiment, the processing module 520 can be used to perform the operation S220 described above, which will not be elaborated here.

[0115] The sending module 530 is configured to send a thermal runaway warning message for the target lithium battery to the terminal in response to the energy change information being greater than the target threshold. In one embodiment, the sending module 530 can be used to perform the operation S230 described above, which will not be elaborated here.

[0116] According to an embodiment of the present invention, the target period is T moments, and T is an integer greater than 1. The processing module 520 includes a first processing sub-module and a second processing sub-module.

[0117] The first processing sub-module is configured to process the charging voltage at the (t - 1)th moment, the charging voltage at the tth moment, and the charging current at the tth moment, and generate energy change information of the (t - 1)th period, where t = 2, 3,..., T. The second processing sub-module is configured to integrate the energy change information of T - 1 periods to generate energy change information of the target period.

[0118] According to an embodiment of the present invention, the sending module 530 includes an extraction sub-module, a third processing sub-module, a correction sub-module, and a determination sub-module.

[0119] An extraction sub-module is used to obtain the voltage change information and the predetermined charging current after the target lithium battery is charged at a predetermined constant current to a predetermined state of charge and then left standing under normal operating conditions. A third processing sub-module is used to process the predetermined charging current and multiple voltage change information within a predetermined time period to generate allowed energy change information. A correction sub-module is used to generate a target threshold based on a predetermined coefficient and the allowed energy change information. A determination sub-module is used to send a control instruction to the circuit breaker connected to the target lithium battery in the energy storage power station to isolate the target lithium battery from the battery pack operating normally in the energy storage power station in response to not receiving feedback information from the terminal regarding the thermal runaway warning information within a predetermined time period.

[0120] According to an embodiment of the present invention, any multiple of the acquisition module 510, the processing module 520, and the sending module 530 can be combined and implemented in one module, or any one of them can be split into multiple modules. Or, at least part of the functions of one or more of these modules can be combined with at least part of the functions of other modules and implemented in one module. According to an embodiment of the present invention, at least one of the acquisition module 510, the processing module 520, and the sending module 530 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 by any other reasonable means such as integrating or packaging circuits, etc., in hardware or firmware, or implemented in any one of the three implementation manners of software, hardware, and firmware, or in an appropriate combination of any several of them. Or, at least one of the acquisition module 510, the processing module 520, and the sending module 530 can be at least partially implemented as a computer program module, and when the computer program module is run, it can execute the corresponding functions.

[0121] According to an embodiment of the present invention, the acquisition module collects real-time information on the charging voltage and charging current of the lithium battery cells in the energy storage power station to form a full battery pack coverage monitoring; the processing module sets the characteristic of the continuous voltage drop of the lithium battery in the energy storage power station during constant current charging as the trigger condition for thermal runaway warning, continuously collects the voltage and current of the target lithium battery cell that meets the trigger condition for thermal runaway warning, and integrates the product of the voltage change amount and the current of the target lithium battery cell, and collects and amplifies the thermal runaway characteristics as energy change information to achieve fast anomaly detection and improve the accuracy of warning; the dynamic threshold adjustment in the sending module can significantly shorten the warning time and avoid false alarms.

[0122] Figure 6 The block diagram of an electronic device suitable for implementing the method for thermal runaway warning of lithium batteries in an energy storage power station according to an embodiment of the present invention is shown.

[0123] AsFigure 6 As shown, the electronic device 600 according to an embodiment of the present invention includes a processor 601, which can perform various appropriate actions and processes according to a program stored in the ROM 602 or a program loaded into the RAM 603 from the storage section 608. The ROM is a read-only memory, and the RAM is a random access memory. The processor 601 can include, for example, a general microprocessor (such as a CPU), an instruction set processor, and / or a related chipset, and / or a dedicated microprocessor, such as an application specific integrated circuit (ASIC), etc. The processor 601 can also include on-board memory for caching purposes. The processor 601 can 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.

[0124] In the RAM 603, various programs and data required for the operation of the electronic device 600 are stored. The processor 601, the ROM 602, and the RAM 603 are connected to each other via a bus 604. The processor 601 performs various operations of the method flow according to an embodiment of the present invention by executing the program in the ROM 602 and / or the RAM 603. It should be noted that the program can also be stored in one or more memories other than the ROM 602 and the RAM 603. The processor 601 can also perform various operations of the method flow according to an embodiment of the present invention by executing the program stored in the one or more memories.

[0125] According to an embodiment of the present invention, the electronic device 600 may further include an input / output I / O interface 605, and the input / output I / O interface 605 is also connected to the bus 604. The electronic device 600 may further include one or more of the following components connected to the I / O interface 605: an input section 606 including a keyboard, a mouse, etc.; an output section 607 including, for example, a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 608 including a hard disk, etc.; and a communication section 609 including a network interface card such as a LAN card, a modem, etc. The communication section 609 performs communication processing via a network such as the Internet. A drive 610 is also connected to the I / O interface 605 as needed. A removable medium 611, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 610 as needed, so that a computer program read from it can be installed into the storage section 608 as needed.

[0126] 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 without being assembled into the device / apparatus / system. The above computer-readable storage medium carries one or more programs, and when the above one or more programs are executed, the method according to the embodiments of the present invention is implemented.

[0127] According to an embodiment of the present invention, the computer-readable storage medium may be a non-volatile computer-readable storage medium, for example, it may include but is not limited to: portable computer disks, hard disks, RAM, ROM, erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above. In the present invention, the computer-readable storage medium may be any tangible medium that contains or stores a program, and this program can be used by or in combination with an instruction execution system, device, or apparatus. For example, according to an embodiment of the present invention, the computer-readable storage medium may include the above-described ROM 602 and / or RAM 603 and / or one or more memories other than ROM 602 and RAM 603.

[0128] An embodiment of the present invention further includes a computer program product, which includes a computer program that contains program code for executing the method shown in the flowchart. When the computer program product runs in a computer system, the program code is used to enable the computer system to implement the energy storage power station lithium battery thermal runaway warning method provided by the embodiments of the present invention.

[0129] When the computer program is executed by the processor 601, the above functions defined in the system / apparatus of the embodiments of the present invention are executed. According to an embodiment of the present invention, the above-described systems, apparatuses, modules, units, etc. can be implemented by computer program modules.

[0130] In one embodiment, the computer program may rely on tangible storage media such as optical storage devices and magnetic storage devices. In another embodiment, the computer program may also be transmitted and distributed in the form of signals on a network medium, and be downloaded and installed through the communication part 609, and / or be installed from the removable medium 611. The program code included in the computer program can be transmitted by any suitable network medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0131] In such an embodiment, the computer program can be downloaded and installed from a network through the communication part 609, and / or installed from the removable medium 611. When the computer program is executed by the processor 601, the above functions defined in the system of the embodiment of the present invention are executed. According to an embodiment of the present invention, the above-described system, device, apparatus, module, unit, etc. can be implemented by computer program modules.

[0132] According to an embodiment of the present invention, the program code for executing the computer program provided in the embodiment of the present invention can be written in any combination of one or more programming languages. Specifically, these computing programs can be implemented using high-level procedures and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages include, but are not limited to, such as Java, C++, Python, the "C" language, 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, by using an Internet service provider to connect through the Internet).

[0133] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagram may represent a module, a program segment, or a part of code, and the above module, program segment, or part of code 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 blocks may occur in a different order than marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram or flowchart, and the combination of blocks in the block diagram or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions.

[0134] Those skilled in the art can understand that the features described in various embodiments of the present invention can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, without departing from the spirit and teachings of the present invention, the features described in various embodiments of the present invention can be combined and combined in various ways. All such combinations and / or combinations fall within the scope of the present invention.

[0135] The embodiments of the present invention have been described above. However, these embodiments are merely for illustrative purposes and not for limiting the scope of the present invention. Although the embodiments have been described separately above, this does not mean that the measures in each embodiment cannot be used advantageously in combination. Without departing from the scope of the present invention, those skilled in the art can make various substitutions and modifications, and these substitutions and modifications should all fall within the scope of the present invention.

Claims

1. A thermal runaway early warning method for lithium batteries in energy storage power stations, characterized in that: The method comprises: Obtain the charging current and charging voltage of the target lithium battery at each moment during the constant current charging process; In response to determining that the charging voltages at adjacent moments in a target period continue to decrease, processing a plurality of charging currents and a plurality of charging voltages at a plurality of moments in the target period to generate energy change information of the target lithium battery in the target period; and In response to the energy change information being greater than a target threshold, thermal runaway warning information for the target lithium battery is sent to the terminal; wherein the target threshold is dynamically configured based on the voltage change information and the predetermined charging current after the target lithium battery is left at rest when it is charged to a predetermined load at a predetermined constant current under normal operating conditions.

2. The method according to claim 1, characterized in that The target period is T moments, where T is an integer greater than 1; In response to determining that the charging voltages at adjacent moments in the target time period continue to decrease, processing multiple charging currents and multiple charging voltages at multiple moments in the target time period to generate energy change information of the target lithium battery in the target time period includes: Processing the charging voltage at time t-1, the charging voltage at time t, and the charging current at time t to generate energy change information for time period t-1, where t=2, 3, ..., T; and The energy change information in the target time period is generated according to the energy change information in the T-1 time period; wherein the energy change information in the target time period is the integration of the energy change information in the T-1 time period.

3. The method according to claim 1 or 2, characterized in that The method further comprises: In response to not receiving feedback information regarding the thermal runaway warning information from the terminal within a predetermined time period, a control instruction is sent to a circuit breaker connected to the target lithium battery in the energy storage power station to isolate the target lithium battery from the normally operating battery pack in the energy storage power station.

4. The method according to claim 1, wherein The method further comprises: Obtaining voltage change information and a predetermined charging current after the target lithium battery is left at rest when the target lithium battery is charged to a predetermined load at a predetermined constant current under normal operating conditions; and The predetermined charging current and the plurality of voltage change information within a predetermined period are processed to generate the target threshold.

5. The method according to claim 4, characterized in that The processing of the predetermined charging current and the plurality of voltage change information within a predetermined period to generate the target threshold value includes: Processing the predetermined charging current and the plurality of voltage change information within a predetermined period to generate allowable energy change information; and The target threshold is generated based on a predetermined coefficient and the allowable energy change information.

6. A thermal runaway warning device for lithium batteries in energy storage power stations, characterized in that: Includes: An acquisition module is used to obtain the charging current and charging voltage of the target lithium battery at each moment during the constant current charging process; a processing module, configured to, in response to determining that the charging voltages at adjacent moments in a target time period continue to decrease, process a plurality of charging currents and a plurality of charging voltages at a plurality of moments in the target time period to generate energy change information of the target lithium battery in the target time period; and A sending module is used to send thermal runaway warning information for the target lithium battery to the terminal in response to the energy change information being greater than a target threshold; wherein the target threshold is dynamically configured based on the voltage change information and the predetermined charging current of the target lithium battery after it is left at rest when it is charged to a predetermined load at a predetermined constant current under normal operating conditions.

7. An electronic device, characterized in that: include: one or more processors; a memory for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors are enabled to implement the method according to any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that Executable instructions are stored thereon, which, when executed by a processor, enable the processor to implement the method according to any one of claims 1 to 5.

9. A computer program product, characterized in that A computer program is included which, when executed by a processor, implements the method according to any one of claims 1 to 5.

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