Abnormal self-checking method and system for lithium battery group

Abstract

The invention relates to the related field of lithium battery safety management, and discloses an abnormity self-checking method and system for a lithium battery group, the charging and discharging process data of the lithium battery group is recorded, the battery polarization state of a lithium battery unit can be evaluated according to the charging and discharging data record, and the battery polarization state of the lithium battery unit can be evaluated in the same lithium battery group. The use conditions of the lithium battery units are basically consistent, so that the abnormal aging or damage state of the lithium battery can be judged, the purpose of abnormal self-inspection of the lithium battery group is achieved, and the lithium battery group can conveniently perform safety management on the units in the group based on safety.

Description

Technical Field

[0001] The present invention relates to the field of lithium battery safety management, and in particular to an abnormality self-detection method and system for a lithium battery group. Background Art

[0002] In order to enable the battery platform to provide higher output and more efficient input, small battery groups are usually used in the existing technology. The small battery group approach also has better resistance and safety when facing external force damage. The battery structure is not easily damaged and causes uncontrollable battery combustion. At the same time, the small battery group approach also provides a certain battery damage margin and local maintainability.

[0003] However, the prior art self-checking methods for battery groups mostly use built-in battery management systems, which usually include the remaining capacity of the battery, the expected available battery life, and the battery health status. Most of the monitoring is the overall use evaluation of the battery unit in a safe state, but there is a lack of effective judgment on the unconventional risks of the battery unit during use. Local problems of the battery group cannot be discovered and handled in a timely manner, which may lead to further expansion of hidden dangers. Summary of the invention

[0004] The object of the present invention is to provide a method and system for abnormality self-detection of a lithium battery group to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: An abnormality self-detection method for a lithium battery group, comprising: Monitoring and recording of charging and discharging data of lithium battery groups; monitoring the charging and discharging of lithium battery units in the group through the sensor monitoring units corresponding to the lithium battery groups, and obtaining the real-time status data of the voltage and current of the lithium battery group during the charging and discharging process; Drawing of charge and discharge record curves; drawing the recorded status data in sequence based on the time sequence direction to obtain the dynamic monitoring curve of the corresponding lithium battery unit in the lithium battery group, the dynamic monitoring curve includes a charging curve and a discharging curve, which is used to characterize the current-voltage correspondence in the lithium battery charging and discharging; Calculation of polarization voltage of lithium battery group; Calculate the polarization voltage of lithium battery unit based on charging curve and discharging curve, obtain polarization data of corresponding lithium battery unit and polarization dynamic correlation curve corresponding to current, wherein the polarization voltage is the difference between open circuit voltage and working voltage; Abnormal judgment and output based on polarization voltage; multiple polarization dynamic correlation curves corresponding to the lithium battery units in the lithium battery group are superimposed under equal conditions, and multiple polarization dynamic correlation curves are discretely analyzed based on current coordinates and basic evaluation models. When the discreteness of a polarization dynamic correlation curve exceeds the rated range, the corresponding lithium battery unit is marked as abnormal.

[0006] As a further solution of the present invention, the steps of characterizing the working conditions of the basic evaluation model and evaluating the abnormality of the lithium battery group are also included, specifically including: Obtaining a lithium battery evaluation model that matches the lithium battery group, wherein the lithium battery evaluation model is used to characterize the polarization performance of the corresponding type of lithium battery under different charging and discharging conditions; Acquire the charge and discharge cycle records of the lithium battery group, and characterize and evaluate the charge cycle model according to the lithium battery aging model, acquire the polarization characteristic quantity of the current lithium battery group, and superimpose the polarization characteristic quantity on the lithium battery evaluation model to acquire the basic evaluation model of the lithium battery group; An overall offset judgment is performed based on the discrete analysis results of the lithium battery group and the basic evaluation model. If the offset difference is determined to be a positive value and exceeds a preset rated range, the corresponding lithium battery group is marked as abnormal.

[0007] As a further solution of the present invention: it also includes risk management and self-checking and judging steps of lithium battery units, specifically including: When a lithium battery unit in the lithium battery group is marked as abnormal, a group control signal is generated to control the corresponding lithium battery unit to be deconstructed from the group circuit; Applying a small AC voltage at different frequencies to the lithium battery unit based on AC impedance spectroscopy technology, and recording the corresponding current response to obtain a series of complex impedance data points; The original data of the lithium battery unit is obtained, and the equivalent circuit is fitted to calculate the corresponding polarization resistance, and the abnormality of the lithium battery unit is judged based on the polarization resistance.

[0008] As a further solution of the present invention: polarization is used to characterize the phenomenon that the electrode deviates from the equilibrium potential when the current passes through the electrode. When the polarization voltage is characterized as abnormally enhanced, the risk tendency of the lithium battery unit includes: The unusual additional generation and accumulation of heat creates a risk of high temperature in the lithium battery unit. The high heat accumulation affects the lithium battery material, increasing the internal pressure of the lithium battery. The polarization degree of the lithium battery units in the lithium battery group is inconsistent, making the synchronous control of charging and discharging ineffective.

[0009] As a further solution of the present invention: it also includes the steps of recording and matching the remaining capacity of the lithium battery, specifically including: When monitoring the charge and discharge of the lithium battery cells in the group, the current remaining capacity state of the corresponding lithium battery cells is synchronously obtained, and the historical polarization change curve of the lithium battery cells under the same remaining capacity state is obtained through the historical record data, and the slope of the historical polarization change curve is judged to obtain the decay rate of the current lithium battery cell. When the decay rate of the lithium battery cell is greater than that of other lithium battery cells in the lithium battery group, the lithium battery cell is marked as an abnormal candidate, and the abnormal candidate is used to characterize that the polarization degree of the lithium battery cell is within the rated range, but the polarization trend is abnormal.

[0010] The embodiment of the present invention aims to provide an abnormality self-detection system for a lithium battery group, comprising: The monitoring data recording module is used for monitoring and recording the charging and discharging data of the lithium battery group; the charging and discharging of the lithium battery units in the group are monitored through the sensor monitoring unit corresponding to the lithium battery group, and the real-time status data of the voltage and current of the lithium battery group during the charging and discharging process are obtained; A charge and discharge curve generation module is used to draw the charge and discharge record curve; the recorded state data is drawn in sequence based on the time sequence direction to obtain the dynamic monitoring curve of the corresponding lithium battery unit in the lithium battery group, and the dynamic monitoring curve includes a charge curve and a discharge curve, which is used to characterize the current-voltage correspondence in the lithium battery charge and discharge; The polarization intensity calculation module is used to calculate the polarization voltage of the lithium battery group; the polarization voltage of the lithium battery unit is calculated based on the charging curve and the discharging curve, and the polarization data of the corresponding lithium battery unit and the polarization dynamic correlation curve corresponding to the current are obtained. The polarization voltage is the difference between the open circuit voltage and the working voltage; The lithium battery abnormality self-judgment module is used for abnormality judgment and output based on polarization voltage; it performs equal condition superposition on several polarization dynamic correlation curves corresponding to the lithium battery units in the lithium battery group, and performs discrete analysis on several polarization dynamic correlation curves based on current coordinates and basic evaluation models. When the discreteness of a polarization dynamic correlation curve exceeds the rated range, the corresponding lithium battery unit is marked as abnormal.

[0011] As a further solution of the present invention: it also includes a basic model characterization module, specifically including: A model matching unit, used to obtain a lithium battery evaluation model that matches the lithium battery group, wherein the lithium battery evaluation model is used to characterize the polarization performance of the corresponding type of lithium battery under different charging and discharging conditions; A model characterization unit, used to obtain the charge and discharge cycle records of the lithium battery group, and perform characterization evaluation on the charging cycle model according to the lithium battery aging model, obtain the polarization characteristic quantity of the current lithium battery group, and superimpose the polarization characteristic quantity on the lithium battery evaluation model to obtain the basic evaluation model of the lithium battery group; The group offset judgment unit is used to perform overall offset judgment based on the discrete analysis result of the lithium battery group and the basic evaluation model. If the offset difference is judged to be a positive value and exceeds a preset rated range, the corresponding lithium battery group is marked as abnormal.

[0012] As a further solution of the present invention: it also includes a risk limit verification module, specifically including: An abnormality control unit, used for generating a group control signal to control the corresponding lithium battery unit to be deconstructed from the group circuit when a lithium battery unit in the lithium battery group is marked as abnormal; An abnormality self-detection unit, used for applying a small AC voltage at different frequencies to the lithium battery unit based on AC impedance spectroscopy technology, and recording the corresponding current response to obtain a series of complex impedance data points; The abnormality verification unit is used to obtain the original data of the lithium battery unit, perform equivalent circuit fitting, calculate and obtain the corresponding polarization resistance, and perform abnormal complex judgment on the lithium battery unit based on the polarization resistance.

[0013] As a further solution of the present invention: polarization is used to characterize the phenomenon that the electrode deviates from the equilibrium potential when the current passes through the electrode. When the polarization voltage is characterized as abnormally enhanced, the risk tendency of the lithium battery unit includes: The unusual additional generation and accumulation of heat creates a risk of high temperature in the lithium battery unit. The high heat accumulation affects the lithium battery material, increasing the internal pressure of the lithium battery. The polarization degree of the lithium battery units in the lithium battery group is inconsistent, making the synchronous control of charging and discharging ineffective.

[0014] As a further solution of the present invention: it also includes a trend judgment module; The trend judgment module is used to synchronously obtain the current remaining capacity state of the corresponding lithium battery unit when monitoring the charging and discharging of the lithium battery units in the group, and obtain the historical polarization change curve of the lithium battery unit under the same remaining capacity state through the historical record data, and perform slope judgment on the historical polarization change curve to obtain the decay rate of the current lithium battery unit. When the decay rate of the lithium battery unit is greater than that of other lithium battery units in the lithium battery group, the lithium battery unit is marked as an abnormal candidate, and the abnormal candidate is used to indicate that the polarization degree of the lithium battery unit is within the rated range, but the polarization trend is abnormal.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: by recording the process data of charging and discharging of the lithium battery group, the battery polarization state of the lithium battery unit can be evaluated according to the charging and discharging data records. In the same lithium battery group, the operating conditions of the lithium battery units are basically the same, so it is possible to judge the abnormal aging or damage state of the lithium battery, so as to achieve the purpose of abnormal self-detection of the lithium battery group, and facilitate the lithium battery group to perform safety management of the units in the group based on safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The present invention is a flowchart of an abnormality self-detection method for a lithium battery group.

[0017] Figure 2 The present invention is a flowchart of abnormality judgment of a lithium battery group in an abnormality self-detection method for a lithium battery group.

[0018] Figure 3 The present invention is a flowchart of the risk management and self-checking determination steps in a method for abnormal self-checking of a lithium battery group.

[0019] Figure 4 The present invention is a block diagram of a component of an abnormality self-detection system for a lithium battery group. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0022] like Figure 1 The above is an abnormality self-detection method for a lithium battery group provided by an embodiment of the present invention, comprising the following steps: S10, monitoring and recording the charging and discharging data of the lithium battery group; monitoring the charging and discharging of the lithium battery units in the group through the sensor monitoring unit corresponding to the lithium battery group, and obtaining the real-time status data of the voltage and current of the lithium battery group during the charging and discharging process; S20, drawing a charge and discharge record curve; drawing the recorded state data in sequence based on the time sequence direction to obtain a dynamic monitoring curve of the corresponding lithium battery unit in the lithium battery group, wherein the dynamic monitoring curve includes a charging curve and a discharging curve, which is used to characterize the current-voltage correspondence in the lithium battery charging and discharging; S30, calculating the polarization voltage of the lithium battery group; calculating the polarization voltage of the lithium battery unit based on the charging curve and the discharging curve, obtaining polarization data of the corresponding lithium battery unit and a polarization dynamic correlation curve corresponding to the current, wherein the polarization voltage is the difference between the open circuit voltage and the working voltage; S40, abnormal judgment and output based on polarization voltage; multiple polarization dynamic correlation curves corresponding to the lithium battery units in the lithium battery group are superimposed under equal conditions, and multiple polarization dynamic correlation curves are discretely analyzed based on current coordinates and basic evaluation models. When the discreteness of a polarization dynamic correlation curve exceeds the rated range, the corresponding lithium battery unit is marked as abnormal.

[0023] In this embodiment, a method for abnormal self-detection of lithium battery groups is provided. By recording the process data of charging and discharging of the lithium battery group, the battery polarization state of the lithium battery unit can be evaluated according to the charging and discharging data records. In the same lithium battery group, the use conditions of the lithium battery units are basically the same. Therefore, it is possible to judge the abnormal aging or damage state of the lithium battery, so as to achieve the purpose of abnormal self-detection of the lithium battery group, and facilitate the lithium battery group to safely manage the units in the group based on safety. In the use of batteries in the prior art, in order to enable the platform to provide higher output and more efficient input, a small battery group is usually used to achieve this. At the same time, compared with large batteries, the small battery group has better resistance and safety when facing external damage, and the battery structure is less likely to be damaged and cause uncontrollable battery combustion. At the same time, the small battery group method also provides certain battery damage margin and local maintainability; the specific implementation principle of the abnormal self-check of the battery group in this embodiment is to evaluate whether the lithium battery unit is abnormal by judging the polarization state of the battery, because in the same lithium battery group, the working conditions of the lithium battery units are basically the same, so under the ideal state, the aging loss degree of the lithium battery units in the group should be similar or even the same, therefore, by judging the degree of polarization, the abnormal judgment of the lithium battery unit can be realized; the specific judgment of the degree of polarization adopts the calculation method of polarization voltage, that is, by subtracting the open circuit voltage of the lithium battery unit and the actual working voltage under different working conditions, so as to obtain the polarization state under different working conditions, and by performing discrete analysis on the planned states of multiple lithium battery units in the lithium battery group, the lithium battery units that are obviously deviated from the average state of the group (that is, the normal state under no fault use) can be screened out, that is, the abnormal lithium battery units.

[0024] like Figure 2 As shown, as another preferred embodiment of the present invention, it also includes the steps of characterizing the working conditions of the basic evaluation model and evaluating the abnormality of the lithium battery group, specifically including: S51, obtaining a lithium battery evaluation model matched with the lithium battery group, wherein the lithium battery evaluation model is used to characterize the polarization performance of the corresponding type of lithium battery under different charging and discharging conditions; S52, obtaining the charge and discharge cycle records of the lithium battery group, and performing characterization evaluation on the charge cycle model according to the lithium battery aging model, obtaining the polarization characteristic quantity of the current lithium battery group, and superimposing the polarization characteristic quantity on the lithium battery evaluation model to obtain the basic evaluation model of the lithium battery group; S53, performing overall offset judgment based on the discrete analysis result of the lithium battery group and the basic evaluation model, if the offset difference is judged to be a positive value and exceeds a preset rated range, marking the corresponding lithium battery group as abnormal.

[0025] In this embodiment, a lithium battery evaluation model based on the type of lithium battery is added. Its function is to understand the cumulative impact of different working conditions of the same type of lithium battery group on the polarization of lithium batteries under normal use through big data synchronization, and then make an overall evaluation and judgment on the lithium battery group, that is, the theoretical value of the polarization degree of the lithium battery group can be judged through the working record of the lithium battery group. This theoretical value is evaluated based on the rules obtained from a large number of usage records of the same type of lithium battery group. Therefore, if the current lithium battery group far exceeds this theoretical value, it indicates that there is a problem with its overall quality, or the current usage condition has seriously exceeded the safe usage condition range of this type of lithium battery. Therefore, it is necessary to mark it as abnormal to limit the user's use and encourage the user to conduct safety inspections and repairs in a timely manner.

[0026] like Figure 3 As shown, as another preferred embodiment of the present invention, it also includes risk management and self-checking and judging steps of lithium battery units, specifically including: S61, when a lithium battery unit in the lithium battery group is marked as abnormal, generating a group control signal to control the corresponding lithium battery unit to be deconstructed from the group circuit; S62, applying a small AC voltage at different frequencies to the lithium battery unit based on AC impedance spectroscopy technology, and recording corresponding current responses to obtain a series of complex impedance data points; S63, obtaining the original data of the lithium battery unit, performing equivalent circuit fitting, calculating and obtaining the corresponding polarization resistance, and performing abnormal complex determination on the lithium battery unit based on the polarization resistance.

[0027] In this embodiment, for lithium battery cells that are initially judged to be abnormal, further identification and judgment through polarization resistance measurement is provided, that is, AC impedance spectroscopy technology, which can measure the internal resistance and polarization resistance of the battery. The principle is to apply a small AC voltage at different frequencies. By analyzing the impedance spectrum obtained, parameters such as ohmic resistance, electrochemical polarization resistance and concentration polarization resistance can be separated, so as to further accurately evaluate and judge the health status of the lithium battery cells marked as abnormal.

[0028] As another preferred embodiment of the present invention, polarization is used to characterize the phenomenon that the electrode deviates from the equilibrium potential when the current passes through the electrode. When the polarization voltage is characterized as abnormally enhanced, the risk tendency of the lithium battery unit includes: The unusual additional generation and accumulation of heat creates a risk of high temperature in the lithium battery unit. The high heat accumulation affects the lithium battery material, increasing the internal pressure of the lithium battery. The polarization degree of the lithium battery units in the lithium battery group is inconsistent, making the synchronous control of charging and discharging ineffective.

[0029] In this embodiment, as the polarization of the lithium battery increases, the risk to the continued use of the lithium battery will gradually increase. The increased energy loss during the charging and discharging process will lead to a decrease in the actual battery usable amount. At the same time, the degradation of the battery's chemical composition will also lead to a decrease in the number of available cycles of the battery. But more importantly, it has an impact on safety in use. Polarization will cause additional heat to be generated inside the battery. During long-term high-power charging and discharging of the battery, the heat is extremely easy to accumulate, which may cause the battery to exceed the safety temperature threshold, increase the internal pressure of the battery, and reduce the stability of the internal materials. In such a situation, safety accidents are very likely to occur.

[0030] As another preferred embodiment of the present invention, the step of recording and matching the remaining capacity of the lithium battery is also included, which specifically includes: When monitoring the charge and discharge of the lithium battery cells in the group, the current remaining capacity state of the corresponding lithium battery cells is synchronously obtained, and the historical polarization change curve of the lithium battery cells under the same remaining capacity state is obtained through the historical record data, and the slope of the historical polarization change curve is judged to obtain the decay rate of the current lithium battery cell. When the decay rate of the lithium battery cell is greater than that of other lithium battery cells in the lithium battery group, the lithium battery cell is marked as an abnormal candidate, and the abnormal candidate is used to characterize that the polarization degree of the lithium battery cell is within the rated range, but the polarization trend is abnormal.

[0031] In the present embodiment, the simultaneous recording of lithium capacity and the attenuation judgment of lithium battery units are supplemented. For various batteries including lithium batteries, when charging and discharging, when the remaining capacity of the battery is different, the charging and discharging working performance is also different. Especially in the discharge process, when the remaining capacity of the battery decreases, the peak voltage level that can be provided by the discharge will decay to a certain extent. Therefore, by recording and matching the current capacity remaining state of the lithium battery unit, a more accurate and reliable polarization evaluation result can be obtained. Here, by judging the historical polarization change rate of the lithium battery at the same capacity state, it is possible to sense when rapid polarization occurs within a certain period of time, and judge that the operating conditions within this cycle exceed the normal use range of the lithium battery unit, resulting in the occurrence of unconventional polarization phenomena. Therefore, it can be marked as an abnormal candidate to inform the user.

[0032] like Figure 4 As shown, the present invention also provides an abnormality self-detection system for a lithium battery group, which comprises: The monitoring data recording module 100 is used for monitoring and recording the charging and discharging data of the lithium battery group; the charging and discharging of the lithium battery units in the group are monitored by the sensor monitoring unit corresponding to the lithium battery group, and the real-time status data of the voltage and current of the lithium battery group during the charging and discharging process are obtained; The charge and discharge curve generation module 200 is used for drawing the charge and discharge record curve; the recorded state data is sequentially drawn based on the time sequence direction to obtain the dynamic monitoring curve of the corresponding lithium battery unit in the lithium battery group, and the dynamic monitoring curve includes a charge curve and a discharge curve, which is used to characterize the current-voltage correspondence in the lithium battery charge and discharge; The polarization intensity calculation module 300 is used to calculate the polarization voltage of the lithium battery group; the polarization voltage of the lithium battery unit is calculated based on the charging curve and the discharging curve, and the polarization data of the corresponding lithium battery unit and the polarization dynamic correlation curve corresponding to the current are obtained. The polarization voltage is the difference between the open circuit voltage and the working voltage; The lithium battery abnormality self-judgment module 400 is used for abnormality judgment and output based on polarization voltage; multiple polarization dynamic correlation curves corresponding to the lithium battery units in the lithium battery group are superimposed under equal conditions, and multiple polarization dynamic correlation curves are discretely analyzed based on current coordinates and basic evaluation models. When the discreteness of a certain polarization dynamic correlation curve exceeds the rated range, the corresponding lithium battery unit is marked as abnormal.

[0033] As another preferred embodiment of the present invention, it also includes a basic model characterization module, specifically including: A model matching unit, used to obtain a lithium battery evaluation model that matches the lithium battery group, wherein the lithium battery evaluation model is used to characterize the polarization performance of the corresponding type of lithium battery under different charging and discharging conditions; A model characterization unit, used to obtain the charge and discharge cycle records of the lithium battery group, and perform characterization evaluation on the charging cycle model according to the lithium battery aging model, obtain the polarization characteristic quantity of the current lithium battery group, and superimpose the polarization characteristic quantity on the lithium battery evaluation model to obtain the basic evaluation model of the lithium battery group; The group offset judgment unit is used to perform overall offset judgment based on the discrete analysis result of the lithium battery group and the basic evaluation model. If the offset difference is judged to be a positive value and exceeds a preset rated range, the corresponding lithium battery group is marked as abnormal.

[0034] As another preferred embodiment of the present invention, it also includes a risk limit verification module, specifically including: An abnormality control unit, used for generating a group control signal to control the corresponding lithium battery unit to be deconstructed from the group circuit when a lithium battery unit in the lithium battery group is marked as abnormal; An abnormality self-detection unit, used for applying a small AC voltage at different frequencies to the lithium battery unit based on AC impedance spectroscopy technology, and recording the corresponding current response to obtain a series of complex impedance data points; The abnormality verification unit is used to obtain the original data of the lithium battery unit, perform equivalent circuit fitting, calculate and obtain the corresponding polarization resistance, and perform abnormal complex judgment on the lithium battery unit based on the polarization resistance.

[0035] As another preferred embodiment of the present invention, polarization is used to characterize the phenomenon that the electrode deviates from the equilibrium potential when the current passes through the electrode. When the polarization voltage is characterized as abnormally enhanced, the risk tendency of the lithium battery unit includes: The unusual additional generation and accumulation of heat creates a risk of high temperature in the lithium battery unit. The high heat accumulation affects the lithium battery material, increasing the internal pressure of the lithium battery. The polarization degree of the lithium battery units in the lithium battery group is inconsistent, making the synchronous control of charging and discharging ineffective.

[0036] As another preferred embodiment of the present invention, it also includes a trend judgment module; The trend judgment module is used to synchronously obtain the current remaining capacity state of the corresponding lithium battery unit when monitoring the charging and discharging of the lithium battery units in the group, and obtain the historical polarization change curve of the lithium battery unit under the same remaining capacity state through the historical record data, and perform slope judgment on the historical polarization change curve to obtain the decay rate of the current lithium battery unit. When the decay rate of the lithium battery unit is greater than that of other lithium battery units in the lithium battery group, the lithium battery unit is marked as an abnormal candidate, and the abnormal candidate is used to indicate that the polarization degree of the lithium battery unit is within the rated range, but the polarization trend is abnormal.

[0037] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0038] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the disclosure in the specification and examples. This application is intended to cover any variations, uses or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the claims.

[0039] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A method for abnormal self-detection of lithium battery groups, characterized in that: Include: Monitoring and recording of charging and discharging data of lithium battery groups; monitoring the charging and discharging of lithium battery units in the group through the sensor monitoring units corresponding to the lithium battery groups, and obtaining the real-time status data of the voltage and current of the lithium battery group during the charging and discharging process; Drawing of charge and discharge record curves; drawing the recorded status data in sequence based on the time sequence direction to obtain the dynamic monitoring curve of the corresponding lithium battery unit in the lithium battery group, the dynamic monitoring curve includes a charging curve and a discharging curve, which is used to characterize the current-voltage correspondence in the lithium battery charging and discharging; Calculation of polarization voltage of lithium battery group; Calculate the polarization voltage of lithium battery unit based on charging curve and discharging curve, obtain polarization data of corresponding lithium battery unit and polarization dynamic correlation curve corresponding to current, wherein the polarization voltage is the difference between open circuit voltage and working voltage; Abnormal judgment and output based on polarization voltage; Several polarization dynamic correlation curves corresponding to the lithium battery units in the lithium battery group are superimposed under equal conditions, and several polarization dynamic correlation curves are discretely analyzed based on current coordinates and basic evaluation models. When the discreteness of a polarization dynamic correlation curve exceeds the rated range, the corresponding lithium battery unit is marked as abnormal.

2. The abnormality self-detection method for a lithium battery group according to claim 1, characterized in that: It also includes the steps of characterizing the working conditions of the basic evaluation model and evaluating the abnormality of the lithium battery group, specifically including: Obtaining a lithium battery evaluation model that matches the lithium battery group, wherein the lithium battery evaluation model is used to characterize the polarization performance of the corresponding type of lithium battery under different charging and discharging conditions; Acquire the charge and discharge cycle records of the lithium battery group, and characterize and evaluate the charge cycle model according to the lithium battery aging model, acquire the polarization characteristic quantity of the current lithium battery group, and superimpose the polarization characteristic quantity on the lithium battery evaluation model to acquire the basic evaluation model of the lithium battery group; An overall offset judgment is performed based on the discrete analysis results of the lithium battery group and the basic evaluation model. If the offset difference is determined to be a positive value and exceeds a preset rated range, the corresponding lithium battery group is marked as abnormal.

3. The abnormality self-detection method for a lithium battery group according to claim 2, characterized in that: It also includes risk management and self-testing steps for lithium battery units, including: When a lithium battery unit in the lithium battery group is marked as abnormal, a group control signal is generated to control the corresponding lithium battery unit to be deconstructed from the group circuit; Applying a small AC voltage at different frequencies to the lithium battery unit based on AC impedance spectroscopy technology, and recording the corresponding current response to obtain a series of complex impedance data points; The original data of the lithium battery unit is obtained, and the equivalent circuit is fitted to calculate the corresponding polarization resistance, and the abnormality of the lithium battery unit is judged based on the polarization resistance.

4. The abnormality self-detection method for a lithium battery group according to claim 1, characterized in that: Polarization is used to characterize the phenomenon that an electrode deviates from the equilibrium potential when current passes through the electrode. When the polarization voltage is characterized as abnormally enhanced, the risk tendency of the lithium battery unit includes: The unusual additional generation and accumulation of heat creates a risk of high temperature in the lithium battery unit. The high heat accumulation affects the lithium battery material, increasing the internal pressure of the lithium battery. The polarization degree of the lithium battery units in the lithium battery group is inconsistent, making the synchronous control of charging and discharging ineffective.

5. The abnormality self-detection method for a lithium battery group according to claim 1, characterized in that: It also includes the steps of recording and matching the remaining capacity of lithium batteries, including: When monitoring the charge and discharge of the lithium battery cells in the group, the current remaining capacity state of the corresponding lithium battery cells is synchronously obtained, and the historical polarization change curve of the lithium battery cells under the same remaining capacity state is obtained through the historical record data, and the slope of the historical polarization change curve is judged to obtain the decay rate of the current lithium battery cell. When the decay rate of the lithium battery cell is greater than that of other lithium battery cells in the lithium battery group, the lithium battery cell is marked as an abnormal candidate, and the abnormal candidate is used to characterize that the polarization degree of the lithium battery cell is within the rated range, but the polarization trend is abnormal.

6. An abnormality self-detection system for a lithium battery group, characterized in that: Include: The monitoring data recording module is used for monitoring and recording the charging and discharging data of the lithium battery group; the charging and discharging of the lithium battery units in the group are monitored through the sensor monitoring unit corresponding to the lithium battery group, and the real-time status data of the voltage and current of the lithium battery group during the charging and discharging process are obtained; A charge and discharge curve generation module is used to draw the charge and discharge record curve; the recorded state data is drawn in sequence based on the time sequence direction to obtain the dynamic monitoring curve of the corresponding lithium battery unit in the lithium battery group, and the dynamic monitoring curve includes a charge curve and a discharge curve, which is used to characterize the current-voltage correspondence in the lithium battery charge and discharge; The polarization intensity calculation module is used to calculate the polarization voltage of the lithium battery group; the polarization voltage of the lithium battery unit is calculated based on the charging curve and the discharging curve, and the polarization data of the corresponding lithium battery unit and the polarization dynamic correlation curve corresponding to the current are obtained. The polarization voltage is the difference between the open circuit voltage and the working voltage; Lithium battery abnormality self-judgment module, used for abnormality judgment and output based on polarization voltage; Several polarization dynamic correlation curves corresponding to the lithium battery units in the lithium battery group are superimposed under equal conditions, and several polarization dynamic correlation curves are discretely analyzed based on current coordinates and basic evaluation models. When the discreteness of a polarization dynamic correlation curve exceeds the rated range, the corresponding lithium battery unit is marked as abnormal.

7. The abnormality self-detection system for lithium battery group according to claim 6, characterized in that: It also includes basic model characterization modules, including: A model matching unit, used to obtain a lithium battery evaluation model that matches the lithium battery group, wherein the lithium battery evaluation model is used to characterize the polarization performance of the corresponding type of lithium battery under different charging and discharging conditions; A model characterization unit, used to obtain the charge and discharge cycle records of the lithium battery group, and perform characterization evaluation on the charging cycle model according to the lithium battery aging model, obtain the polarization characteristic quantity of the current lithium battery group, and superimpose the polarization characteristic quantity on the lithium battery evaluation model to obtain the basic evaluation model of the lithium battery group; The group offset judgment unit is used to perform overall offset judgment based on the discrete analysis result of the lithium battery group and the basic evaluation model. If the offset difference is judged to be a positive value and exceeds a preset rated range, the corresponding lithium battery group is marked as abnormal.

8. The abnormality self-detection system for lithium battery group according to claim 7, characterized in that: It also includes a risk limit assessment module, which includes: An abnormality control unit, used for generating a group control signal to control the corresponding lithium battery unit to be deconstructed from the group circuit when a lithium battery unit in the lithium battery group is marked as abnormal; An abnormality self-detection unit, used for applying a small AC voltage at different frequencies to the lithium battery unit based on AC impedance spectroscopy technology, and recording the corresponding current response to obtain a series of complex impedance data points; The abnormality verification unit is used to obtain the original data of the lithium battery unit, perform equivalent circuit fitting, calculate and obtain the corresponding polarization resistance, and perform abnormal complex judgment on the lithium battery unit based on the polarization resistance.

9. The abnormality self-detection system for lithium battery group according to claim 6, characterized in that: Polarization is used to characterize the phenomenon that an electrode deviates from the equilibrium potential when current passes through the electrode. When the polarization voltage is characterized as abnormally enhanced, the risk tendency of the lithium battery unit includes: The unusual additional generation and accumulation of heat creates a risk of high temperature in the lithium battery unit. The high heat accumulation affects the lithium battery material, increasing the internal pressure of the lithium battery. The polarization degree of the lithium battery units in the lithium battery group is inconsistent, making the synchronous control of charging and discharging ineffective.

10. The abnormality self-detection system for lithium battery group according to claim 6, characterized in that: It also includes a trend judgment module; The trend judgment module is used to synchronously obtain the current remaining capacity state of the corresponding lithium battery unit when monitoring the charging and discharging of the lithium battery units in the group, and obtain the historical polarization change curve of the lithium battery unit under the same remaining capacity state through the historical record data, and perform slope judgment on the historical polarization change curve to obtain the decay rate of the current lithium battery unit. When the decay rate of the lithium battery unit is greater than that of other lithium battery units in the lithium battery group, the lithium battery unit is marked as an abnormal candidate, and the abnormal candidate is used to indicate that the polarization degree of the lithium battery unit is within the rated range, but the polarization trend is abnormal.

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