A multi-terminal battery balancing detection method and device

Abstract

The present invention provides a multi-terminal battery balancing detection method and device, including obtaining battery operation data of each terminal; processing the battery operation data of each terminal to obtain the target cell of each terminal; processing all target cells in each terminal to obtain a point target cell data set; obtaining the total ranking value of the target cell of each terminal based on the status indicators of the point target cell data set of all terminals; determining the abnormal terminal among all terminals based on the target cell of each terminal and the total ranking value of the target cell of each terminal; and judging whether the abnormal terminal is battery balanced based on the status indicators in the abnormal terminal. The present invention not only saves a lot of battery data storage but also reduces calculations, resource reading, etc. in the balancing detection process, thereby improving the efficiency of balancing judgment. In addition, in the balancing detection process, the globality of balancing detection judgment is improved by jointly processing multiple terminals.

Description

Technical Field

[0001] The present invention relates to battery technology, and in particular to a multi-terminal battery balancing detection method and device. Background Art

[0002] At present, in order to solve the problem of time-consuming and labor-intensive power battery fault diagnosis, many battery abnormality diagnosis methods based on real-time battery operation data have been proposed by researchers. For example, patent document CN 112986834 A (application number 202110216741.3) discloses a battery safety monitoring method based on voltage sorting, which belongs to the field of fault diagnosis. The method first collects data from the vehicle's T-BOX in real time, and performs data preprocessing and distributed real-time calculation of single cell voltage and voltage data filtering. Then, by analyzing the sorting value of the filtered battery cell voltage, the critical value Ф of the number of times the sorting number value drops to 1 continuously is determined. Then, the cells whose sorting number value drops to 1 for Ф consecutive times are found to judge the sorting abnormality condition. By comparing with the set voltage sorting abnormality rule critical value and threshold, it is determined whether the cell is abnormal.

[0003] This method uses voltage sorting for analysis, but requires access to operational data for all cells in each terminal's battery pack. This requires direct or indirect access to individual cell voltage data, which significantly increases data storage and management requirements. Therefore, this data is typically stored and accessed via big data platforms based on distributed processing frameworks. In practice, when diagnosing and predicting faulty cells, analysis often spans beyond a single terminal. Consequently, these analysis methods, which rely on individual cell voltage data, consume significant storage and computing resources, and are complex to process. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a multi-terminal battery balancing detection method and device to solve the problem of resource waste in the prior art.

[0005] To achieve the above and other related objectives, the present invention provides a multi-terminal battery balancing detection method, which includes at least the following steps:

[0006] Obtain battery operation data of each terminal;

[0007] The battery operation data of each terminal is processed to obtain the target monomer of each terminal;

[0008] All target monomers in each terminal are processed to obtain a point target monomer data set;

[0009] Obtain the total ranking value of each terminal's target monomer according to the status indicators of the point target monomer data set of all terminals;

[0010] Determine abnormal terminals among all terminals according to the target monomers of each terminal and the total ranking value of the target monomers of the terminals;

[0011] Determine whether the abnormal terminal has battery balance based on the status indicators of the abnormal terminal.

[0012] Preferably, the battery operation data of each terminal is processed to obtain the target monomer of each terminal, including:

[0013] Process the battery operation data to obtain the full charge point and discharge cut-off point;

[0014] Obtaining corresponding charging terminals and discharging terminals based on all the full charging points, all the discharge cut-off points, and the battery operation data;

[0015] The lowest voltages of the battery cells in all charging terminals and all discharging terminals of each terminal are processed to obtain the charging target cell and the discharging target cell.

[0016] Preferably, the battery operation data includes a time sequence, single cell voltage data at each time and the corresponding cell number, system SOC, current and BMS wake-up signal; wherein the single cell voltage data includes the highest cell voltage and the lowest cell voltage.

[0017] Preferably, the point target cell data set includes a full charge point target cell data set and a discharge cut-off point target cell data set.

[0018] Preferably, the state indicators include the terminal pressure difference, the average change rate of the pressure difference, the positive point ratio of the pressure difference change rate, and the positive point ratio of the second-order change rate of the pressure difference;

[0019] The terminal voltage difference is the difference between the highest voltage of the battery cell and the lowest voltage of the battery cell corresponding to the last target cell moment in the point target data set;

[0020] The average rate of change of pressure difference is the ratio of the difference between the final pressure difference and the initial pressure difference to the corresponding time difference △T;

[0021] The ratio of positive points of the pressure difference change rate is the ratio of positive points of the pressure difference change rate at any two adjacent moments;

[0022] The ratio of positive points of the second-order rate of change of pressure difference is the ratio of all positive points of the second-order rate of change of pressure difference at any two adjacent moments.

[0023] Preferably, obtaining the total ranking value of the target monomer of each terminal according to the status indicators of the point target monomer data sets of all terminals includes:

[0024] According to the point target monomer data set of each terminal, the size of all status indicators in the corresponding terminal is obtained;

[0025] Sort the sizes of the same target single state indicators in all terminals and record the sorting values ​​of each state indicator;

[0026] The total ranking value of the target monomer of each terminal is obtained based on the ranking values ​​of all status indicators in each terminal.

[0027] Preferably, obtaining the target monomer total ranking value of each terminal according to the ranking values ​​of all status indicators in each terminal includes:

[0028] According to the ranking values ​​of all status indicators of each terminal, the total ranking value of the full charge point and the total ranking value of the discharge cutoff point of the corresponding terminal are obtained;

[0029] The target monomer total ranking value of the terminal is obtained according to the total ranking value of the full charge point and the total ranking value of the discharge cut-off point of the terminal.

[0030] Preferably, determining abnormal terminals among all terminals according to the target monomers of the terminals and the total ranking values ​​of the target monomers of the terminals includes:

[0031] When the lowest cell number of the charging target cell and the lowest cell number of the discharging target cell in the terminal are the same, the terminal is regarded as the target terminal;

[0032] The abnormal terminal is determined based on the total ranking value of the target monomer in the target terminal.

[0033] Preferably, whether the abnormal terminal is battery balanced is determined based on the terminal pressure difference and the average change rate of the pressure difference in the abnormal terminal.

[0034] To achieve the above-mentioned and other related objectives, the present invention provides a multi-terminal battery balancing detection device, comprising a processor and a memory. The memory stores a computer program executable on the processor. When the computer program is executed by the processor, the steps of the multi-terminal battery balancing detection method described above are implemented.

[0035] As described above, the multi-terminal battery balancing detection method and device of the present invention have the following beneficial effects:

[0036] The invention proposes a multi-terminal battery balancing detection method and device. Each terminal only needs to store the single-cell voltage data for the highest and lowest battery cell voltages at each moment. This not only significantly reduces battery data storage but also reduces the computation and resource access required during the balancing detection process, thereby improving the efficiency of balancing judgment. Furthermore, by jointly processing multiple terminals during the balancing detection process, the overall effectiveness of multi-terminal balancing detection and judgment is enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a flow chart of the multi-terminal battery balancing detection method of the present invention.

[0038] Figure 2 It shows a schematic structural diagram of a multi-terminal battery balancing detection device according to the present invention. DETAILED DESCRIPTION

[0039] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0040] See also Figure 1-2 It should be noted that the diagrams provided in this embodiment are merely schematic illustrations of the basic concept of the present invention. Therefore, the diagrams only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0041] Method Example:

[0042] The process of a multi-terminal battery balancing detection method of the present invention is as follows: Figure 1 As shown, according to Figure 1 The technical solution of the multi-terminal battery balancing detection method of the present invention is described in detail. The method at least includes:

[0043] S1, obtain battery operation data of each terminal;

[0044] In an embodiment of the present invention, the battery operation data of each terminal includes a time sequence, single cell voltage data at each time and the corresponding cell number, system SOC (state of charge), current and BMS wake-up signal; wherein, the single cell voltage data includes the highest cell voltage and the lowest cell voltage, and the corresponding cell numbers are the highest cell number and the lowest cell number.

[0045] As another embodiment, the battery operation data further includes the maximum temperature and the minimum temperature at each time.

[0046] S2, processing the battery operation data of each terminal to obtain the target cell of each terminal; the target cell includes a charging target cell and a discharging target cell;

[0047] This step is to process the battery operation data to determine the target cells that may cause battery imbalance. Specifically, it includes:

[0048] S21, processing the battery operation data to obtain a full charge point and a discharge cut-off point;

[0049] The battery operation data is processed to obtain a full charge point; specifically, points corresponding to the battery operation data that meet a first set of set conditions are selected as full charge points; the first set of set conditions include:

[0050] ①BMS wake-up signal shows the critical point between charging and discharging stages;

[0051] ② The system SOC is greater than a first set threshold; in the embodiment of the present invention, the first set threshold is 98.5%.

[0052] ③ The current value is smaller than the first set current value. In the embodiment of the present invention, the first set current value is 1A, wherein a positive current value is regarded as discharging, and a negative current value is regarded as charging.

[0053] ④ The highest voltage is greater than the set voltage. In the embodiment of the present invention, the set voltage is 3.45V.

[0054] This step processes the battery operation data of a terminal based on the first set of set conditions to obtain M full charging points.

[0055] The battery operation data is processed to obtain a discharge cutoff point; specifically, points corresponding to the battery operation data that meet a second set of set conditions are selected as discharge cutoff points; the second set of set conditions include:

[0056] ① The BMS wake-up signal shows the critical point between the discharge segment and the non-discharge segment;

[0057] ② The system SOC is less than a second set threshold; in the embodiment of the present invention, the second set threshold is 70%.

[0058] ③ The current value is smaller than the second set current value; in the embodiment of the present invention, the second set current value is 10A.

[0059] This step processes the battery operation data of a terminal based on the second set of set conditions to obtain N discharge cut-off points.

[0060] S22, obtaining corresponding charging terminals and discharging terminals based on all the full charging points, all the discharge cut-off points, and the battery operation data;

[0061] This step specifically obtains a number of charging terminals according to the full charge point and the battery operation data, and obtains a number of discharging terminals according to the discharge cut-off point and the battery operation data.

[0062] Based on all full charge points and battery operation data, the corresponding charging terminals include:

[0063] (1) Obtain the corresponding initial charging data set based on the voltage data of each full charging point and a certain number of single cells before the full charging point;

[0064] This step specifically combines the full charge point and a certain number of battery cell voltage data before the full charge point to form an initial charging data set. The full charge points obtained in step S21 are M, so there are M initial charging data sets. It should be noted that the number of battery cell voltage data before different full charge points can vary. For example, three consecutive battery cell voltage data can be collected before the first full charge point, and eight consecutive battery cell voltage data can be collected before the third full charge point. In this embodiment of the present invention, no more than ten battery cell voltage data can be collected before the full charge point.

[0065] (2) processing each of the initial charging data sets to obtain a corresponding initial charging terminal;

[0066] This step specifically involves filtering each initial charging data set to obtain the corresponding initial charging terminal. The filtering process should meet the first set of filtering conditions:

[0067] ①The BMS wake-up signal shows charging;

[0068] ② The time difference between two adjacent data points is less than a first set time interval; in the embodiment of the present invention, the first set time interval is 1 minute;

[0069] ③ The current value is smaller than the set current. In the embodiment of the present invention, the set current is 1A.

[0070] Through this step, the battery cell voltage data before the full charge point in each initial charging data is processed to obtain M initial charging terminals.

[0071] (3) All initial charging terminals are processed to obtain all charging terminals of the terminal.

[0072] In this step, all initial charging terminals are processed to obtain all charging terminals of the terminal.

[0073] Specifically, processing all initial charging terminals is to determine whether the time interval between the last set of single-cell battery voltage data and the first set of single-cell battery voltage data of two adjacent initial charging terminals is less than a first set interval threshold; if it is less than, the initial charging terminal with the earlier time among the adjacent ones is discarded, and then all charging terminals of the terminal are obtained.

[0074] In this embodiment of the present invention, the first set interval threshold is 2 hours. For example, if the time interval between the last set of single-cell voltage data of the k-1th initial charging terminal and the first set of single-cell voltage data of the k-1th initial charging terminal is less than 2 hours, then the k-1th initial charging terminal is discarded. In this case, the number of charging terminals m obtained at this time is less than the number of full-charge points M. Otherwise, if there is no initial charging terminal to be discarded, the number of charging terminals m obtained is equal to the number of full-charge points M.

[0075] Therefore, the number m of charging terminals in the terminal is less than or equal to the number M of full charging points.

[0076] Based on all discharge cut-off points and battery operation data, the corresponding discharge end includes:

[0077] (1) Obtaining the corresponding initial discharge data set based on the voltage data of each discharge cutoff point and a certain number of single cells before the discharge cutoff point;

[0078] This step specifically combines the discharge cutoff point and a certain number of single cell voltage data sets before the discharge cutoff point to form an initial discharge data set. The discharge cutoff points obtained in step S21 are N discharge cutoff points, so there are N initial discharge data sets. It should be noted that the number of single cell voltage data sets before different discharge cutoff points can vary. For example, two consecutive single cell voltage data sets can be collected before the first discharge cutoff point, and seven consecutive single cell voltage data sets can be collected before the fourth discharge cutoff point. In this embodiment of the present invention, no more than ten single cell voltage data sets can be selected before the discharge cutoff point.

[0079] (2) processing each of the initial discharge data sets to obtain a corresponding initial discharge end;

[0080] This step specifically involves screening each initial discharge data set to obtain the corresponding initial discharge end; the screening process should meet the second set of screening conditions:

[0081] ①The BMS wake-up signal shows non-charging;

[0082] ② The time difference between two adjacent data points is less than the second set time interval; in the embodiment of the present invention, the second set time interval is 1 minute.

[0083] Through this step, the single cell voltage data before the discharge cut-off point in each initial discharge data is processed to obtain N initial discharge ends.

[0084] (3) All initial discharge ends are processed to obtain all discharge ends of the terminal.

[0085] In this step, all initial discharge ends are processed to obtain all discharge ends of the terminal.

[0086] Specifically, processing all initial discharge terminals is to determine whether the time interval between the last set of battery cell voltage data and the first battery cell voltage data of two adjacent initial discharge terminals is less than a second set interval threshold; if it is less than, discard the initial discharge terminal with the earlier time in the adjacent terminals, and then obtain all discharge terminals of the terminal.

[0087] In this embodiment of the present invention, the second set interval threshold is 2 hours. For example, if the time interval between the last set of single cell voltage data at the kth initial discharge end and the first set of single cell voltage data at the k+1th initial discharge end is less than 2 hours, then the kth initial discharge end is discarded. In this case, the number of discharge ends obtained, n, is less than the number of full charge points, N. Otherwise, if there is no initial discharge end to be discarded, the number of discharge ends obtained, n, is equal to the number of full charge points, N.

[0088] Therefore, the number n of discharge terminals in the terminal is less than or equal to the number N of full charge points.

[0089] S23 , processing the lowest voltages of battery cells in all charging terminals and all discharging terminals of each terminal to obtain target charging cells and target discharging cells.

[0090] In the present invention, the lowest voltage of the battery cells at all charging terminals of each terminal is processed to obtain the charging target cell. Specifically, the frequency of occurrence of the lowest cell number corresponding to the lowest voltage of the battery cells in all charging terminals in the terminal is counted, and the battery cell with the highest frequency of occurrence of the lowest cell number is used as the charging target cell (if the cells have the same frequency of occurrence, they are all used as charging target cells). For example, a terminal has two charging terminals (with an interval greater than 2h), namely [1,2,2,3,1,1,1,1,2,1] and [3,1,1,2,3,1,1,2,1,1]. The numbers in the brackets represent the lowest cell numbers corresponding to the lowest voltage of each battery cell at the corresponding moment. The lowest cell number 1 has the highest frequency of occurrence, which is 12 times, and its frequency is 12 / 20=0.6. Therefore, the lowest cell number 1 in the charging terminal data is the charging target cell. Similarly, the discharge target cell in each terminal can also be determined.

[0091] S3, processing all target monomers in each terminal to obtain a point target monomer data set;

[0092] The single cell voltage data corresponding to the full charge point and the discharge cut-off point of the target cell in the terminal are filtered to form a point target cell data set.

[0093] Specifically, the single cell voltage data corresponding to the full charge point of all charging target cells are filtered to form the full charge point target cell data set Dchg; that is, the single cell voltage data corresponding to the last lowest cell number in each charging terminal is the single cell voltage data corresponding to the full charge point. For example, according to step S2, a terminal has two charging terminals. Assuming that the lowest cell numbers of the above charging terminals are re-sorted according to the time sequence Ti, then the full charge point target cell corresponding to the target cell 1 in each charging terminal is T 10 With T 20 The single cell voltage data corresponding to the moment can be expressed as D chg ={T 10 (Vmax, Vmin), T 20 Similarly, the voltage data of all target cells corresponding to the discharge cut-off time are filtered to become the target cell data set D at the discharge cut-off time. dch .

[0094] Therefore, the point target monomer data set in the present invention includes a full charge point target monomer data set and a discharge cutoff point target monomer data set. The target monomers in the point target monomer data set are the target monomers corresponding to the full charge point and the target monomers corresponding to the discharge cutoff point, which can also be called point target monomers.

[0095] S4, obtaining the total ranking value of the target monomer of each terminal according to the status indicators of the point target monomer data set of all terminals;

[0096] The state indicators of the present invention include the terminal pressure difference D, the average pressure difference change rate K, the positive point ratio of the pressure difference change rate R k and the positive point ratio R of the second-order rate of change of pressure difference k` .

[0097] In the embodiment of the present invention, the terminal voltage difference D is the difference between the highest voltage of the battery cell and the lowest voltage of the battery cell corresponding to the last target cell moment in the point target data set.

[0098] Specifically, for the full charge point target monomer dataset, the terminal pressure difference is the full charge point target monomer dataset D chg The difference between the highest voltage of the single cell and the lowest voltage of the single cell corresponding to the last full charge point in the data set; for the discharge cutoff point target single cell data set, the terminal voltage difference is the discharge cutoff point target single cell data set D chg The difference between the highest voltage of the single cell and the lowest voltage of the single cell corresponding to the last discharge cut-off point.

[0099] Similarly, the initial voltage difference D0 is the difference between the highest voltage of the battery cell and the lowest voltage of the battery cell corresponding to the first target cell moment in the point target data set.

[0100] In the embodiment of the present invention, the full charge point target monomer data set D obtained in S3 chg The end pressure difference D chg =T 20 (Vmax)-T 20 (Vmin).

[0101] In the embodiment of the present invention, the average change rate of pressure difference K is the ratio of the difference between the end pressure difference and the starting pressure difference to the corresponding time difference ΔT; it is expressed as: K = (D i -D0) / ΔT.

[0102] Specifically, for the full charge point target monomer data set, the difference between the end pressure difference and the starting pressure difference is divided by the difference between the last full charge point moment and the first full charge point moment to obtain the average change rate of the pressure difference in the full charge point target monomer data set; for the discharge cutoff point target monomer data set, the difference between the end pressure difference and the starting pressure difference is divided by the difference between the last discharge cutoff point moment and the first discharge cutoff point moment to obtain the average change rate of the pressure difference in the discharge cutoff point target monomer data set.

[0103] In the embodiment of the present invention, the positive point ratio R of the pressure difference change rate k The ratio of the pressure difference change rate between any two adjacent moments is a positive number, and its determination method includes the following steps:

[0104] (1) Calculate the pressure difference D of each target monomer at the corresponding moment i ;

[0105] (2) Calculate the pressure difference change rate K between any two adjacent moments i , and get the pressure difference change rate array [K1, K2,…, K j ]; where i<j, j={m,n}.

[0106] Specifically, K i =(D i -D i-1 ) / △T i , all the calculated pressure difference change rates are arranged in time sequence to form a pressure difference change rate array;

[0107] (3) Obtaining a ratio of positive points of the pressure difference change rate according to the pressure difference change rate array; the positive points indicate that the pressure difference change rate is a positive value.

[0108] The ratio of positive points of the pressure difference change rate is a ratio of the number of positive points of the pressure difference change rate in the first set number to the first set number.

[0109] If the number of pressure differential change rates in the pressure differential change rate array is greater than the first set number, then the pressure differential change rate corresponding to the first set number is the continuous pressure differential change rate of the last first set number in the pressure differential change rate array; if the number of pressure differential change rates in the pressure differential change rate array is less than the first set number, then the number of pressure differential change rates is used as the first set number, that is, statistical calculation is performed based on all pressure differential change rates in the pressure differential change rate array.

[0110] For example, if the number is set to 10 and there are 15 pressure differential change rates in the pressure differential change rate array, then the number of positive values ​​of the last 10 pressure differential change rates, that is, the number of positive points, is counted, and the ratio of the number of positive points to 10 is the positive point ratio of the pressure differential change rate; if the number is set to 10 and there are only 8 pressure differential change rates in the pressure differential change rate array, then the ratio of the number of positive values ​​of the 8 pressure differential change rates to 8 is used as the positive point ratio of the pressure differential change rate.

[0111] In the embodiment of the present invention, the positive point ratio R of the second-order rate of change of the pressure difference k` The ratio of all positive points of the second-order rate of change of the pressure difference between any two adjacent moments; its determination method includes the following steps:

[0112] (1) Calculate the pressure difference D of each target monomer at the corresponding moment i ;

[0113] (2) Calculate the pressure difference change rate K between any two adjacent moments i , and get the pressure difference change rate array [K1, K2,…, K j ]; where i<j, j={m,n}.

[0114] Specifically, K i =(D i -D i-1 ) / △T i , all the calculated pressure difference change rates are arranged in time sequence to form a pressure difference change rate array;

[0115] (3) The pressure difference change rate array is processed to obtain the pressure difference second-order change rate array [K`1, K`2, ..., K` h ]; wherein, i<h, h={m-1,n-1}.

[0116] Specifically, K` i =(K i -K i-1 ) / (△T i -△T i-1 ), first calculate the pressure difference second-order change rate K' according to the two adjacent pressure difference change rates in the pressure difference change rate array, and then arrange all the calculated pressure difference second-order change rates in time sequence to form a pressure difference second-order change rate array.

[0117] It should be noted that if there is △T i -△T i-1 The situation leads to the calculation of K` i If the point is infinite, it will be discarded directly.

[0118] (4) Obtaining the ratio of positive points of the second-order pressure difference change rate according to the pressure difference second-order change rate array; the positive points indicate that the pressure difference change rate is a positive value.

[0119] The ratio of positive points of the second-order change rate of the pressure difference is the ratio of the number of positive points of the second-order change rate of the pressure difference in the second set number to the second set number.

[0120] If the number of pressure differential change rates in the pressure differential second-order change rate array is greater than the second set number, then the pressure differential second-order change rate corresponding to the second set number is the continuous pressure differential second-order change rate of the last second set number in the pressure differential change rate array; if the number of pressure differential change rates in the pressure differential second-order change rate array is less than the second set number, then the number of pressure differential second-order change rates is used as the second set number, that is, statistical calculation is performed based on all pressure differential second-order change rates in the pressure differential second-order change rate array.

[0121] The second set number can be the same as or different from the first set number. In an embodiment of the present invention, the second set number is the same. For example, if the set number is 10 and there are 18 pressure differential change rates in the pressure differential second-order change rate array, then the number of positive values ​​of the last 10 pressure differential second-order change rates is counted, i.e., the number of positive points, and the ratio of the number of positive points to 10 is the positive point ratio of the pressure differential second-order change rate. If the set number is 10 and there are only 7 pressure differential change rates in the pressure differential change rate array, then the ratio of the number of positive values ​​of the 7 pressure differential change rates to 7 is used as the positive point ratio of the pressure differential second-order change rate.

[0122] The total ranking value of the target monomer of each terminal is obtained based on the status indicators of the point target monomer data set of all terminals, including:

[0123] S41, obtaining the size of all status indicators of the corresponding terminal according to the point target monomer data set of each terminal;

[0124] According to the calculation and determination method of the state index of the target cell in each terminal, the state index of the full charge point target cell data set and the state index of the discharge cut-off point target cell data set can be calculated respectively.

[0125] The status indicators of each full charge point target monomer data set are the charging terminal voltage difference D_chg, the average change rate of the charging voltage difference K_chg, and the positive point ratio of the charging voltage difference change rate R k_ Ratio of the positive points of chg and the second-order change rate of the charging voltage difference R k` _chg.

[0126] The state indicators of each target monomer data set at each discharge cutoff point are the discharge end voltage difference D_dch, the average change rate of the discharge voltage difference K_dch, and the positive point ratio of the discharge voltage difference change rate R k_ The positive point ratio R of the second-order rate of change of dch and discharge voltage difference k` _dch.

[0127] S42, sorting the sizes of the same target single state indicators in all terminals and recording the sorting values ​​of the state indicators;

[0128] Sort the charging terminal voltage difference D_chg of the full charge point target monomer data set of all terminals in descending order, and record the charging terminal voltage difference ranking value r(D_chg) of different terminals; similarly, record the charging voltage difference average change rate ranking value r(K_chg) of different terminals, the positive point ratio ranking value r(R k_ chg) and the positive point ratio ranking value r(R k` _chg).

[0129] At the same time, the discharge end voltage difference D_dch of the discharge cutoff point target monomer data set in all terminals is sorted in descending order, and the discharge end voltage difference ranking value r(D_dch) of different terminals is recorded; similarly, the discharge voltage difference average change rate ranking value r(K_dch) of different terminals and the positive point ratio ranking value r(R k_ dch) and the positive point ratio ranking value r(R k` _dch).

[0130] S43, obtaining the total ranking value of the target monomer of each terminal according to the ranking values ​​of all status indicators in each terminal.

[0131] It is necessary to first calculate the total ranking value of the full charge point and the total ranking value of the discharge cut-off point of each terminal, and then calculate the total ranking value of the target monomer of the terminal.

[0132] The total ranking value of each terminal's full charge point and discharge cut-off point is equal to the weighted sum of the ranking values ​​of each state indicator. Specifically:

[0133] The total ranking value of full charging points of each terminal is:

[0134] Rank_chg=S1_chg×r(D_chg)+S2_chg×r(K_chg)+S3_chg×r(R k_chg)+S4_chg×r(R k` _chg)

[0135] Among them, S1_chg, S2_chg, S3_chg and S4_chg are proportional coefficients respectively; S1_chg>S2_chg.

[0136] The total ranking value of the discharge cut-off point of each terminal is:

[0137] Rank_dch=S1_dch×r(D_dch)+S2_dch×r(K_dch)+S3_dch×r(R k _dch)+S4_dch×r(R k` _dch)

[0138] Among them, S1_dch, S2_dch, S3_dch and S4_dch are proportional coefficients respectively; S1_dch>S2_dch.

[0139] Finally, the total ranking value of the target monomer of each terminal is calculated as Rand=Rank_chg+Rank_dch.

[0140] S5, determining abnormal terminals among all terminals according to the target monomers of each terminal and the total ranking value of the target monomers of the terminals;

[0141] According to step S2 , the target cell of each terminal is obtained, and the target cell includes a charging target cell and a discharging target cell.

[0142] S51, when the lowest cell number of the charging target cell and the lowest cell number of the discharging target cell in the terminal are the same, the terminal is taken as the target terminal;

[0143] In this embodiment of the present invention, assume there are four terminals, AA, BB, CC, and DD, each with 50 battery cells. Furthermore, the four terminals, AA, BB, CC, and DD, all meet the requirement of having a common target cell. Specifically, the lowest target cell number for charging of terminal AA is a, and the lowest target cell number for discharging is a; the lowest target cell number for charging of terminal BB is b, and the lowest target cell number for discharging is b; the lowest target cell number for charging of terminal CC is c, and the lowest target cell number for discharging is c; and the lowest target cell number for charging of terminal DD is d, and the lowest target cell number for discharging is d. Therefore, the target terminals are AA, BB, CC, and DD.

[0144] If there is no common cell in the terminal, it is judged that the terminal has no abnormality and no abnormal cell. That is, if the lowest cell number of the charging target cell in the terminal is different from the lowest cell number of the discharging target cell, it is judged that there is no abnormal terminal and no abnormal cell in the terminal.

[0145] S52: Determine an abnormal terminal based on the total ranking value of the target monomers in the target terminal.

[0146] The target terminals are sorted according to their total ranking values, and a set number of terminals before the ranking are regarded as abnormal terminals. In the embodiment of the present invention, the set number of terminals can be several target terminals with the highest ranking, or all target terminals.

[0147] In the embodiment of the present invention, the target terminals are AA, BB, CC, and DD, and the original calculation table of all indicator ranking values ​​in each terminal and the total ranking value of the target monomer of each terminal is shown in Table 1, and the ranking process is shown in Table 2.

[0148] Table 1

[0149]

[0150] Table 2

[0151]

[0152] S6, judging whether the abnormal terminal is battery balanced according to the status indicator of the abnormal terminal.

[0153] In the embodiment of the present invention, whether the abnormal terminal is battery balanced is determined based on the terminal pressure difference and the average change rate of the pressure difference in the abnormal terminal.

[0154] The terminal determines whether the balance condition group is balanced:

[0155] ① The charging terminal voltage difference D_chg is greater than the first preset voltage difference threshold T1;

[0156] ②The average change rate of charging voltage difference K_chg is greater than 0;

[0157] ③ The discharge end voltage difference D_dch is greater than the second preset voltage difference threshold T2;

[0158] ④ The average change rate of discharge voltage difference K_dch is greater than 0.

[0159] If the balance condition group is satisfied at the same time, the terminal is determined to be unbalanced; otherwise, the terminal is determined to be under observation and recorded.

[0160] In the embodiment of the present invention, the first preset voltage difference threshold T1 and the second preset voltage difference threshold T2 are related to the battery voltage.

[0161] Compared to methods that perform equalization detection based on historical operating data (all battery cell voltages at all times), the multi-terminal battery equalization detection method proposed in this invention only requires each terminal to store the single cell voltage data of the highest and lowest battery cell voltages at each moment. This not only significantly reduces battery data storage but also reduces calculations and resource reading during the equalization detection process, thereby improving the efficiency of equalization judgment. In addition, during the equalization detection process, the global nature of the equalization detection judgment is improved by jointly processing multiple terminals.

[0162] Device Example:

[0163] The present invention also provides a multi-terminal battery balancing detection device such as Figure 2 As shown, the device includes a processor and a memory, and the memory stores a computer program that can be run on the processor. When the computer program is executed by the processor, the steps of the multi-terminal battery balancing detection method are implemented.

[0164] Since the principles and steps of the multi-terminal battery balancing detection method have been described in detail in the method embodiment, they will not be repeated in this embodiment.

[0165] In summary, the multi-terminal battery balancing detection method and device proposed in the present invention only requires each terminal to store the single-cell voltage data, namely the highest and lowest battery cell voltages at each moment. This not only significantly reduces battery data storage but also reduces computation and resource access during the balancing detection process, thereby improving the efficiency of balancing judgment. Furthermore, during the balancing detection process, the global nature of balancing detection and judgment is enhanced by jointly processing multiple terminals. Therefore, the present invention effectively overcomes the various shortcomings of the existing technology and has high industrial application value.

[0166] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A multi-terminal battery balancing detection method, characterized in that: At least the following steps are included: Obtain battery operation data of each terminal; The battery operation data of each terminal is processed to obtain the target monomer of each terminal; All target monomers in each terminal are processed to obtain a point target monomer data set; Obtain the total ranking value of each terminal's target monomer according to the status indicators of the point target monomer data set of all terminals; Determine abnormal terminals among all terminals according to the target monomers of each terminal and the total ranking value of the target monomers of the terminals; Determine whether the abnormal terminal has battery balancing based on the status indicators of the abnormal terminal; The battery operation data of each terminal is processed to obtain the target monomer of each terminal, including: Process the battery operation data to obtain the full charge point and discharge cut-off point; Obtaining corresponding charging terminals and discharging terminals based on all the full charging points, all the discharge cut-off points, and the battery operation data; The lowest voltages of the battery cells in all charging terminals and all discharging terminals of each terminal are processed to obtain the charging target cell and the discharging target cell respectively; The state indicators include the terminal pressure difference, the average change rate of the pressure difference, the positive point ratio of the pressure difference change rate, and the positive point ratio of the second-order change rate of the pressure difference.

2. The multi-terminal battery balancing detection method according to claim 1, characterized in that: The battery operation data includes a time sequence, single cell voltage data at each time and the corresponding cell number, system SOC, current and BMS wake-up signal; wherein the single cell voltage data includes the highest cell voltage and the lowest cell voltage.

3. The multi-terminal battery balancing detection method according to claim 2, characterized in that: The point target monomer dataset includes a full charge point target monomer dataset and a discharge cutoff point target monomer dataset.

4. The multi-terminal battery balancing detection method according to claim 3, characterized in that: The terminal voltage difference is the difference between the highest voltage of the battery cell and the lowest voltage of the battery cell corresponding to the last target cell moment in the point target data set; The average change rate of the pressure difference is the ratio of the difference between the terminal pressure difference and the initial pressure difference to the corresponding time difference ΔT; The positive point ratio of the differential change rate is the ratio of the positive points of the pressure difference change rate between any two adjacent moments; The ratio of positive points of the second-order change rate of the pressure difference is the ratio of all positive points of the second-order change rate of the pressure difference between any two adjacent moments.

5. The multi-terminal battery balancing detection method according to claim 4, characterized in that: The total ranking value of the target monomer of each terminal is obtained based on the status indicators of the point target monomer data set of all terminals, including: According to the point target monomer data set of each terminal, the size of all status indicators in the corresponding terminal is obtained; Sort the sizes of the same target single state indicators in all terminals and record the sorting values ​​of each state indicator; The total ranking value of the target monomer of each terminal is obtained based on the ranking values ​​of all status indicators in each terminal.

6. The multi-terminal battery balancing detection method according to claim 5, characterized in that: The total ranking value of the target monomer of each terminal obtained based on the ranking values ​​of all status indicators in each terminal includes: According to the ranking values ​​of all status indicators of each terminal, the total ranking value of the full charge point and the total ranking value of the discharge cutoff point of the corresponding terminal are obtained; The target monomer total ranking value of the terminal is obtained according to the total ranking value of the full charge point and the total ranking value of the discharge cut-off point of the terminal.

7. The multi-terminal battery balancing detection method according to claim 6, characterized in that: Determining abnormal terminals among all terminals based on the target monomers of each terminal and the total ranking values ​​of the target monomers of the terminals includes: When the lowest cell number of the charging target cell and the lowest cell number of the discharging target cell in the terminal are the same, the terminal is regarded as the target terminal; The abnormal terminal is determined based on the total ranking value of the target monomer in the target terminal.

8. The multi-terminal battery balancing detection method according to claim 7, characterized in that: Whether the abnormal terminal is battery balanced is determined based on the terminal pressure difference and the average change rate of the pressure difference in the abnormal terminal.

9. A multi-terminal battery balancing detection device, characterized in that: The device includes a processor and a memory, wherein the memory stores a computer program that can be run on the processor, and when the computer program is executed by the processor, the steps of the multi-terminal battery balancing detection method according to any one of claims 1 to 8 are implemented.

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