A method, apparatus and battery management system for monitoring a battery

Abstract

The application discloses a kind of methods for monitoring battery, device and battery management system, the method comprises: the equalization capacity of each cell is monitored, and it is judged whether there is equalization capacity greater than rated allowable equalization capacity cell;If there is equalization capacity greater than rated allowable equalization capacity cell, the first cell of first group is taken as target cell, and it is judged whether there is fault cell in each first cell according to the first equalization capacity of each first cell remaining;If there is no fault cell in each first cell, it is judged whether there is fault cell in the cell group of first cell according to the second equalization capacity of each other cell in the cell group of first cell;If there is fault cell in the cell group of first cell, the position of fault cell is output and abnormal early warning is sent, early warning is sent before the thermal runaway of cell appears, so that the battery in electric vehicle is more reliably monitored, and the safety of battery is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric vehicles, and more particularly, to a method and device for monitoring a battery and a battery management system. BACKGROUND

[0002] Electric vehicle companies have generally launched new energy vehicle models using lithium ion power batteries as energy storage devices. While lithium ion power batteries are widely used, safety problems have emerged, and there have been several new energy vehicle fire accidents.

[0003] In the prior art, whether a cell is faulty is mainly determined by monitoring the voltage, temperature and other parameters of the cell. When the cell is in thermal runaway, even if the voltage, temperature and other parameters of the cell are collected, the cell may have been damaged and cannot be used again.

[0004] Therefore, how to more reliably monitor the battery in an electric vehicle and improve the safety of the battery is a technical problem to be solved at present. SUMMARY

[0005] The embodiments of the present application provide a method and device for monitoring a battery and a battery management system to more reliably monitor the battery in an electric vehicle and improve the safety of the battery.

[0006] In a first aspect, a method for monitoring a battery is provided, which is applied to a battery comprising a plurality of cells. The cells are sorted in ascending order of available capacity and a serial number is added. The cells are divided into a plurality of cell groups according to a preset grouping rule. The cell with the smallest serial number in each cell group is taken as a first cell. The method comprises:

[0007] Monitoring the equalization capacity of each cell and determining whether there is a cell with an equalization capacity greater than a rated allowable equalization capacity;

[0008] If there is a cell with an equalization capacity greater than the rated allowable equalization capacity, the first cell of the first group is taken as a target cell, and whether there is a faulty cell among the first cells is determined according to the first equalization capacity of the remaining first cells;

[0009] If there is no faulty cell among the first cells, whether there is a faulty cell in the cell group where the first cell is located is determined according to the second equalization capacity of the other cells in the cell group;

[0010] If there is a faulty cell in the cell group where the first cell is located, the position of the faulty cell is output and an abnormal warning is issued;

[0011] The equalization capacity is determined according to a difference between the available capacity of the battery cell and a reference capacity, and the reference capacity is the minimum value among the available capacities of the battery cells.

[0012] In some embodiments, after determining whether there is a faulty battery cell in each of the first battery cells according to the first equalization capacities of the remaining first battery cells, the method further comprises:

[0013] If there is the faulty battery cell in each of the first battery cells, outputting a position of the faulty battery cell and issuing an abnormal warning;

[0014] Eliminating the faulty battery cell, reducing the serial number of each battery cell after the faulty battery cell by one, and re-determining each new first battery cell until there is no faulty battery cell in each of the first battery cells.

[0015] In some embodiments, determining whether there is a faulty battery cell in each of the first battery cells according to the first equalization capacities of the remaining first battery cells specifically comprises:

[0016] If each of the first equalization capacities is a third equalization capacity, determining that the target battery cell is the faulty battery cell, and the third equalization capacity is an equalization capacity whose increasing value reaches a preset increasing value within the preset historical time length;

[0017] If there is a fourth equalization capacity in each of the first equalization capacities, determining that a first battery cell corresponding to the fourth equalization capacity is the faulty battery cell, and the fourth equalization capacity is an equalization capacity whose decreasing value reaches a preset decreasing value within the preset historical time length.

[0018] In some embodiments, the method further comprises:

[0019] If the current first equalization capacity is not the fourth equalization capacity, determining that a current first battery cell corresponding to the current first equalization capacity is a normal battery cell, and adding one to the number of the normal battery cells.

[0020] In some embodiments, determining whether there is the faulty battery cell in the battery cell group in which the first battery cell is located according to the second equalization capacities of each other battery cell in the battery cell group in which the first battery cell is located specifically comprises:

[0021] If there is the fourth equalization capacity in each of the second equalization capacities, determining that a battery cell corresponding to the fourth equalization capacity is the faulty battery cell.

[0022] In some embodiments, the method further comprises:

[0023] If the current second equalization capacity is not the fourth equalization capacity, determining that a current battery cell corresponding to the current second equalization capacity is a normal battery cell, and adding one to the number of the normal battery cells.

[0024] In some embodiments, after outputting the location of the faulty battery cell and issuing an anomaly warning, the method further includes:

[0025] Remove the faulty battery cell and decrement the serial number of each battery cell following the faulty one.

[0026] Secondly, a device for monitoring a battery is provided, applied to a battery comprising multiple cells. The method involves pre-sorting the cells according to their available capacity from smallest to largest, assigning serial numbers, and dividing the cells into multiple cell groups according to a preset grouping rule. The cell with the smallest serial number in each cell group is designated as the first cell. The method includes:

[0027] The first judgment module is used to monitor the balanced capacity of each of the cells and determine whether there are cells whose balanced capacity is greater than the rated allowable balanced capacity.

[0028] The second judgment module is used to, if there is a cell with a balanced capacity greater than the rated allowable balanced capacity, take the first cell of the first group as the target cell, and determine whether there is a faulty cell in each of the remaining first cells based on the first balanced capacity of each of the first cells.

[0029] The third judgment module is used to determine whether the faulty cell exists in the cell group where the first cell is located, based on the second equalization capacity of the other cells in the cell group where the first cell is located, if the faulty cell does not exist in any of the first cells.

[0030] The early warning module is used to output the location of the faulty battery cell and issue an abnormality warning if the faulty battery cell is present in the battery cell group where the first battery cell is located.

[0031] The balanced capacity is determined based on the difference between the available capacity of the battery cell and the reference capacity, where the reference capacity is the minimum available capacity among all the battery cells.

[0032] Thirdly, a battery management system is provided, including a device for battery anomaly warning based on equalization capacity as described in the second aspect.

[0033] By applying the above technical scheme, in the battery including a plurality of battery cells, each battery cell is sorted according to the available capacity of each battery cell from small to large in advance, and a serial number is added, and each battery cell is divided into a plurality of battery cell groups according to a preset grouping rule, the battery cell with the smallest serial number in each battery cell group is taken as a first battery cell, the equalization capacity of each battery cell is monitored, and it is judged whether there is a battery cell with an equalization capacity greater than the rated allowable equalization capacity; if there is a battery cell with an equalization capacity greater than the rated allowable equalization capacity, the first battery cell of the first group is taken as a target battery cell, and it is judged whether there is a fault battery cell in each first battery cell according to the first equalization capacity of each first battery cell; if there is no fault battery cell in each first battery cell, it is judged whether there is a fault battery cell in the battery cell group where the first battery cell is located according to the second equalization capacity of each other battery cell in the battery cell group where the first battery cell is located; if there is a fault battery cell in the battery cell group where the first battery cell is located, the position of the fault battery cell is output and an abnormal warning is issued, the judgment of whether there is a fault battery cell is performed based on each battery cell group, the monitoring efficiency is improved, the fault battery cell is effectively tracked by using the change of the equalization capacity, and the position of the fault battery cell is reported in time and an abnormal warning is issued, so that a warning is issued before the battery cell appears thermal runaway, thereby more reliably monitoring the battery in the electric vehicle and improving the safety of the battery. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0035] Figure 1 A flowchart of a method for monitoring a battery according to an embodiment of the present application is shown;

[0036] Figure 2 A flowchart of a method for monitoring a battery according to another embodiment of the present application is shown;

[0037] Figure 3 A structural diagram of a device for monitoring a battery according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0039] The embodiment of the application provides a method for monitoring a battery, which is applied to the battery comprising a plurality of battery cells, each of the battery cells is sorted in advance and added with a serial number, and each of the battery cells is divided into a plurality of battery cell groups according to a preset grouping rule, the battery cell with the smallest serial number in each of the battery cell groups is taken as a first battery cell, and the method comprises the following steps: Figure 1

[0040] In step S101, the equalization capacity of each of the battery cells is monitored, and it is judged whether there is a battery cell with an equalization capacity greater than a rated allowable equalization capacity.

[0041] In the embodiment, the battery is formed by connecting a plurality of single-section battery cells in series, each of the battery cells is sorted in advance according to the available capacity from small to large, and added with a serial number, and divided into a plurality of battery cell groups according to a preset grouping rule, the number of battery cells in each of the battery cell groups can be the same or different, the serial numbers of the battery cells in each of the battery cell groups are sorted from small to large, and the battery cell with the smallest serial number in each of the battery cell groups is the first battery cell in each of the battery cell groups.

[0042] Due to the limitation of the process level, there is a certain difference between the battery cells, and the capacity attenuation of the battery cells is also inconsistent in the use process along with the increase of the charging and discharging cycle number, the storage time and the temperature, etc., so that the SoC (State of Charge) of the battery cells in the same battery group is inconsistent, and the imbalance of the battery cells in the same battery group is caused, therefore, the battery can be balanced by the passive capacity equalization, and the battery cell with a high available capacity is discharged to the same capacity as the battery cell with a low available capacity. The equalization capacity of each of the battery cells is monitored, the equalization capacity is determined according to the difference between the available capacity of the battery cell and the reference capacity, and the reference capacity is the minimum value in the available capacity of each of the battery cells.

[0043] If the equalization capacity of a certain battery cell is greater than the rated allowable equalization capacity, it is indicated that there is a faulty battery cell in each of the battery cells, and the position of the faulty battery cell needs to be further judged so as to perform subsequent processing on the faulty battery cell.

[0044] In step S102, if there is a battery cell with an equalization capacity greater than the rated allowable equalization capacity, the first battery cell in the first group is taken as a target battery cell, and it is judged whether there is a faulty battery cell in each of the first battery cells according to the first equalization capacity of each of the remaining first battery cells.

[0045] In the embodiment, the existence of the faulty battery cell will affect the equalization capacity of the other battery cells, therefore, if there is a battery cell with an equalization capacity greater than the rated allowable equalization capacity, it is indicated that there is a faulty battery cell. The first battery cell in the first group is taken as a target battery cell, and then it is judged whether there is a faulty battery cell in each of the first battery cells according to the first equalization capacity of each of the remaining first battery cells.

[0046] ​It can be understood that if there is no battery cell with an equalization capacity greater than the rated allowable equalization capacity, it indicates that the equalization capacities of the battery cells are in a normal range and there is no faulty battery cell, and the equalization capacities of the battery cells can be continuously monitored.

[0047] In order to accurately determine whether there is a faulty battery cell in each first battery cell, in some embodiments of the present application, whether there is a faulty battery cell in each first battery cell is determined according to the first equalization capacities of the remaining first battery cells, specifically:

[0048] If each first equalization capacity is a third equalization capacity, it is determined that the target battery cell is the faulty battery cell, and the third equalization capacity is an equalization capacity whose increasing value reaches a preset increasing value within the preset historical time length;

[0049] If there is a fourth equalization capacity in each first equalization capacity, it is determined that the first battery cell corresponding to the fourth equalization capacity is the faulty battery cell, and the fourth equalization capacity is an equalization capacity whose decreasing value reaches a preset decreasing value within the preset historical time length.

[0050] In this embodiment, the available capacity of the target battery cell is the minimum value among the available capacities of the battery cells, so the available capacity of the target battery cell is the reference capacity. When the target battery cell fails, it will no longer participate in the capacity equalization operation, which will cause a sudden change in the first equalization capacities of the remaining first battery cells. Therefore, if each first equalization capacity is a third equalization capacity, that is, each first equalization capacity suddenly increases, it indicates that the target battery cell has a fault, and it is determined that the target battery cell is the faulty battery cell. If there is a fourth equalization capacity in each first equalization capacity at this time, that is, one or more first equalization capacities suddenly decrease, it indicates that it is caused by the fault of the first battery cell corresponding to the fourth equalization capacity itself. Therefore, it is determined that the first battery cell corresponding to the fourth equalization capacity is the faulty battery cell.

[0051] In order to ensure that there is no faulty battery cell in each first battery cell, after determining whether there is a faulty battery cell in each first battery cell according to the first equalization capacities of the remaining first battery cells, the method further comprises:

[0052] If there is the faulty battery cell in each first battery cell, output the position of the faulty battery cell and issue an abnormal early warning;

[0053] Eliminate the faulty battery cell, reduce the serial numbers of each battery cell after the faulty battery cell by one, and re-determine each new first battery cell until there is no faulty battery cell in each first battery cell.

[0054] In the embodiment, if there is a faulty cell in each first cell, the position of the faulty cell is outputted and an abnormal early warning is issued to remind the user to handle the faulty cell in time, and then the faulty cell is rejected. Since the serial number is interrupted after the rejection of the faulty cell, the serial number needs to be adjusted, the serial number of each cell after the faulty cell is reduced by one, and each new first cell is determined again. Then, whether there is a faulty cell in each first cell is determined again according to the first equalization capacity of each remaining first cell, until there is no faulty cell in each first cell.

[0055] The rejection of the faulty cell can be automatic closing of the faulty cell, or closing of the faulty cell according to the closing instruction of the user.

[0056] In order to accurately monitor the number of normal cells, the method further comprises:

[0057] If the current first equalization capacity is not the fourth equalization capacity, the current first cell corresponding to the current first equalization capacity is determined to be a normal cell, and the number of normal cells is increased by one.

[0058] In the embodiment, each first cell except the target cell is determined, the current first equalization capacity corresponds to the current first cell, and if the current first equalization capacity is not the fourth equalization capacity, it means that the current first equalization capacity does not suddenly decrease, and the current first cell is a normal cell. The number of normal cells is increased by one.

[0059] In step S103, if there is no faulty cell in each first cell, whether there is a faulty cell in the cell group in which the first cell is located is determined according to the second equalization capacity of each other cell in the cell group.

[0060] In the embodiment, if there is no faulty cell in each first cell, the determination process in the cell group is performed to determine whether there is a faulty cell in each cell group. When the other cells in the cell group except the first cell fail, the equalization capacity of the cell itself changes. According to the second equalization capacity of each other cell in the cell group in which the first cell is located, whether there is a faulty cell in the cell group in which the first cell is located can be determined.

[0061] In order to accurately determine whether there is a faulty cell in the cell group in which the first cell is located, whether there is a faulty cell in the cell group in which the first cell is located is determined according to the second equalization capacity of each other cell in the cell group in which the first cell is located. Specifically:

[0062] If the fourth equalization capacity exists in each second equalization capacity, the cell corresponding to the fourth equalization capacity is determined to be the faulty cell.

[0063] In the embodiment, if the fourth equalization capacity exists in each second equalization capacity, it indicates that the equalization capacity of the battery cell corresponding to the fourth equalization capacity suddenly decreases, and thus the battery cell corresponding to the fourth equalization capacity can be determined as the fault battery cell.

[0064] In order to accurately monitor the number of normal battery cells, in some embodiments of the present application, the method further comprises:

[0065] If the current second equalization capacity is not the fourth equalization capacity, the current battery cell corresponding to the current second equalization capacity is determined as a normal battery cell, and the number of normal battery cells is increased by one.

[0066] In the embodiment, each battery cell in the battery cell group except the first battery cell is determined, the current fourth equalization capacity corresponds to the current battery cell, and if the current second equalization capacity is not the fourth equalization capacity, it indicates that the current battery cell does not suddenly decrease, and the current battery cell is a normal battery cell, and the number of normal battery cells is increased by one.

[0067] In some embodiments of the present application, after the monitoring of all battery cells is completed, the number of normal battery cells and the capacity of each normal battery cell are output, so that the user can more intuitively understand the overall situation of the battery.

[0068] In step S104, if the fault battery cell exists in the battery cell group where the first battery cell is located, the position of the fault battery cell is output, and an abnormal warning is issued.

[0069] In the embodiment, by outputting the position of the fault battery cell and issuing an abnormal warning, a warning can be issued before the battery cell appears thermal runaway, so that the user can replace the fault battery cell in advance through maintenance means to avoid causing greater damage.

[0070] In order to further improve the reliability of monitoring, in some embodiments of the present application, after the position of the fault battery cell is output and the abnormal warning is issued, the method further comprises:

[0071] The fault battery cell is removed, and the serial number of each battery cell after the fault battery cell is reduced by one.

[0072] In the embodiment, by removing the fault battery cell, the fault battery cell is prevented from further deteriorating, and since the serial number is interrupted after the fault battery cell is removed, the serial number of each battery cell after the fault battery cell needs to be adjusted and reduced by one.

[0073] By applying the above technical scheme, in the battery including a plurality of battery cells, each battery cell is sorted in advance according to the available capacity of each battery cell from small to large, and a serial number is added, and each battery cell is divided into a plurality of battery cell groups according to a preset grouping rule, the battery cell with the smallest serial number in each battery cell group is taken as the first battery cell, the equalization capacity of each battery cell is monitored, and it is judged whether there is a battery cell with an equalization capacity greater than the rated allowable equalization capacity; if there is a battery cell with an equalization capacity greater than the rated allowable equalization capacity, the first battery cell of the first group is taken as the target battery cell, and it is judged whether there is a fault battery cell in each first battery cell according to the first equalization capacity of each first battery cell; if there is no fault battery cell in each first battery cell, it is judged whether there is a fault battery cell in the battery cell group where the first battery cell is located according to the second equalization capacity of each other battery cell in the battery cell group where the first battery cell is located; if there is a fault battery cell in the battery cell group where the first battery cell is located, the position of the fault battery cell is output and an abnormal early warning is issued, the judgment of whether there is a fault battery cell is performed based on each battery cell group, the monitoring efficiency is improved, the fault battery cell is effectively tracked by using the change of the equalization capacity, and the position of the fault battery cell is reported in time and an abnormal early warning is issued, so that an early warning is issued before the battery cell appears thermal runaway, and the battery in the electric vehicle is more reliably monitored, and the safety of the battery is improved.

[0074] In order to further illustrate the technical idea of the application, the technical scheme of the application will be described in combination with a specific application scenario.

[0075] The embodiment of the application provides a method for monitoring a battery, which is applied to a battery including a plurality of battery cells, each battery cell is sorted in advance according to the available capacity of each battery cell from small to large, and a serial number is added, and each battery cell is divided into a plurality of battery cell groups according to a preset grouping rule, the battery cell with the smallest serial number in each battery cell group is taken as the first battery cell, as shown in Figure 2 The method comprises the following steps:

[0076] Step S201, start.

[0077] Step S202, monitor the equalization capacity of each battery cell.

[0078] Step S203, whether there is a battery cell with an equalization capacity greater than the rated allowable equalization capacity, if yes, execute step S204, otherwise execute step S217.

[0079] Step S204, the first battery cell of the first battery cell group is taken as the target battery cell.

[0080] Step S205, whether each first equalization capacity is a third equalization capacity, if yes, execute step S206, otherwise execute step S208.

[0081] Step S206, determine that the target battery cell is a fault battery cell.

[0082] Step S207, output the position of the fault cell and issue an abnormality warning, remove the fault cell and determine new first cells, and execute step S204.

[0083] Step S208, whether the first equalization capacity is the fourth equalization capacity, if yes, execute step S209, otherwise execute step S210.

[0084] Step S209, determine that the first cell corresponding to the fourth equalization capacity is a fault cell, and execute step S207.

[0085] Step S210, the current first cell is a normal cell, and the number of normal cells is incremented by one.

[0086] Step S211, whether there is no fourth equalization capacity in each first equalization capacity, if yes, execute step S212, otherwise execute step S208.

[0087] Step S212, whether the second equalization capacity is the fourth equalization capacity, if yes, execute step S213, otherwise execute step S215.

[0088] Step S213, determine that the cell corresponding to the fourth equalization capacity is a fault cell.

[0089] Step S214, output the position of the fault cell and issue an abnormality warning.

[0090] Step S215, the current cell is a normal cell, and the number of normal cells is incremented by one.

[0091] Step S216, whether there is no fourth equalization capacity in each second equalization capacity, if yes, execute step S217, otherwise execute step S212.

[0092] Step S217, end.

[0093] By applying the above technical solution, the judgment of the fault cell is performed based on each cell group, the monitoring efficiency is improved, the change of the equalization capacity is used to effectively track the fault cell, and the position of the fault cell is reported and an abnormality warning is issued in time, so that the warning is issued before the thermal runaway of the cell, thereby more reliably monitoring the battery in the electric vehicle and improving the safety of the battery.

[0094] The embodiment of the application also provides a device for monitoring a battery, which is applied to a battery including a plurality of cells, each cell is sorted according to the available capacity from small to large in advance, and a serial number is added, and each cell is divided into a plurality of cell groups according to a preset grouping rule, and the cell with the smallest serial number in each cell group is taken as a first cell, as shown in the following table. Figure 3 The device includes:

[0095] The first judging module 301 is configured to monitor the equalization capacity of each battery cell and determine whether there is a battery cell with an equalization capacity greater than the rated allowable equalization capacity.

[0096] The second judging module 302 is configured to, if there is a battery cell with an equalization capacity greater than the rated allowable equalization capacity, take the first battery cell in the first group as a target battery cell, and determine whether there is a faulty battery cell in each of the first battery cells according to the first equalization capacity of each of the first battery cells.

[0097] The third judging module 303 is configured to, if there is no faulty battery cell in each of the first battery cells, determine whether there is a faulty battery cell in the battery cell group in which the first battery cell is located according to the second equalization capacity of each of the other battery cells in the battery cell group in which the first battery cell is located.

[0098] The early warning module 304 is configured to, if there is a faulty battery cell in the battery cell group in which the first battery cell is located, output the position of the faulty battery cell and issue an abnormal early warning.

[0099] The equalization capacity is determined according to the difference between the available capacity of the battery cell and the reference capacity, and the reference capacity is the minimum value of the available capacity of each battery cell.

[0100] In a specific application scenario, the early warning module 304 is further configured to:

[0101] if there is a faulty battery cell in each of the first battery cells, output the position of the faulty battery cell and issue an abnormal early warning;

[0102] remove the faulty battery cell, reduce the serial number of each battery cell after the faulty battery cell by one, and re-determine each new first battery cell until there is no faulty battery cell in each of the first battery cells.

[0103] In a specific application scenario, the second judging module 302 is specifically configured to:

[0104] if each of the first equalization capacities is a third equalization capacity, determine that the target battery cell is the faulty battery cell, and the third equalization capacity is an equalization capacity whose increasing value reaches a preset increasing value within the preset historical time length;

[0105] if there is a fourth equalization capacity in each of the first equalization capacities, determine that the first battery cell corresponding to the fourth equalization capacity is the faulty battery cell, and the fourth equalization capacity is an equalization capacity whose decreasing value reaches a preset decreasing value within the preset historical time length.

[0106] In a specific application scenario, the second judging module 302 is further configured to:

[0107] If the current first equalization capacity is not the fourth equalization capacity, it is determined that a current first battery cell corresponding to the current first equalization capacity is a normal battery cell, and the number of the normal battery cell is incremented by one.

[0108] In a specific application scenario, the third determination module 303 is specifically configured to:

[0109] If the fourth equalization capacity exists in the second equalization capacities, it is determined that a battery cell corresponding to the fourth equalization capacity is the fault battery cell.

[0110] In a specific application scenario, the third determination module 303 is further configured to:

[0111] If the current second equalization capacity is not the fourth equalization capacity, it is determined that a current battery cell corresponding to the current second equalization capacity is a normal battery cell, and the number of the normal battery cell is incremented by one.

[0112] In a specific application scenario, the early warning module 304 is further configured to:

[0113] The fault battery cell is removed, and the serial numbers of each battery cell after the fault battery cell are decremented by one.

[0114] By applying the above technical solutions, in a battery including a plurality of battery cells, each battery cell is sorted according to the available capacity from small to large in advance, and a serial number is added, and each battery cell is divided into a plurality of battery cell groups according to a preset grouping rule, and the battery cell with the smallest serial number in each battery cell group is taken as a first battery cell. A device for monitoring the battery includes: a first determination module configured to monitor the equalization capacity of each battery cell and determine whether there is a battery cell with an equalization capacity greater than a rated allowable equalization capacity; a second determination module configured to, if there is a battery cell with an equalization capacity greater than a rated allowable equalization capacity, take the first battery cell of the first group as a target battery cell, and determine whether there is a fault battery cell in each first battery cell according to the first equalization capacity of the remaining first battery cells; a third determination module configured to, if there is no fault battery cell in each first battery cell, determine whether there is a fault battery cell in the battery cell group where the first battery cell is located according to the second equalization capacity of each other battery cell in the battery cell group where the first battery cell is located; and an early warning module configured to, if there is a fault battery cell in the battery cell group where the first battery cell is located, output the position of the fault battery cell and issue an abnormal warning. The determination of whether there is a fault battery cell is performed based on each battery cell group, which improves the monitoring efficiency, effectively tracks the fault battery cell by using the change of the equalization capacity, and timely reports the position of the fault battery cell and issues an abnormal warning, so that the warning can be issued before the thermal runaway of the battery cell, thereby more reliably monitoring the battery in the electric vehicle and improving the safety of the battery.

[0115] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the same; although the present application has been described in detail with reference to the foregoing examples, those of ordinary skill in the art will understand that they can still modify the technical solutions described in the foregoing examples, or make equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for monitoring a battery, characterized in that, The method, applicable to batteries comprising multiple cells, involves pre-sorting the cells according to their available capacity from smallest to largest, assigning serial numbers, and dividing the cells into multiple cell groups according to a preset grouping rule. The cell with the smallest serial number in each cell group is designated as the first cell. Monitor the balanced capacity of each of the cells and determine whether there are any cells whose balanced capacity is greater than the rated allowable balanced capacity. If there is a cell whose balanced capacity is greater than the rated allowable balanced capacity, the first cell of the first group is taken as the target cell, and the presence of a faulty cell in each of the remaining first cells is determined based on the first balanced capacity of each of the first cells. If the faulty cell is not present in any of the first cells, the presence of the faulty cell in the cell group is determined based on the second equalization capacity of the other cells in the cell group where the first cell is located. If the faulty cell is present in the cell group where the first cell is located, output the location of the faulty cell and issue an abnormal warning. The balanced capacity is determined based on the difference between the available capacity of the battery cell and the reference capacity, where the reference capacity is the minimum available capacity among all the battery cells.

2. The method as described in claim 1, characterized in that, After determining whether there is a faulty cell among the remaining first cells based on the first equalization capacity of each of the first cells, the method further includes: If a faulty cell is present in any of the first cells, the location of the faulty cell is output and an abnormality warning is issued. Remove the faulty battery cell, decrement the serial number of each battery cell after the faulty battery cell by one, and re-determine each new first battery cell, until there are no faulty battery cells among the first battery cells.

3. The method as described in claim 1, characterized in that, Based on the first equalization capacity of the remaining first cells, it is determined whether there are faulty cells in each of the first cells, specifically as follows: If each of the first equalization capacities is the third equalization capacity, the target cell is determined to be the faulty cell, and the third equalization capacity is the equalization capacity whose increase value reaches the preset increase value within a preset historical time period. If a fourth equalization capacity exists among the first equalization capacities, the first cell corresponding to the fourth equalization capacity is determined to be the faulty cell, and the fourth equalization capacity is the equalization capacity in which the decrease value reaches the preset decrease value within the preset historical time period.

4. The method as described in claim 3, characterized in that, The method further includes: If the current first equalization capacity is not the fourth equalization capacity, determine that the current first cell corresponding to the current first equalization capacity is a normal cell, and increment the number of normal cells by one.

5. The method as described in claim 3, characterized in that, The presence of the faulty cell in the cell group containing the first cell is determined based on the second equalization capacity of the other cells in the cell group containing the first cell. Specifically: If the fourth equalization capacity exists in each of the second equalization capacities, the cell corresponding to the fourth equalization capacity is determined to be the faulty cell.

6. The method as described in claim 5, characterized in that, The method further includes: If the current second equalization capacity is not the fourth equalization capacity, determine that the current cell corresponding to the current second equalization capacity is a normal cell, and increment the number of normal cells by one.

7. The method as described in claim 1, characterized in that, After outputting the location of the faulty battery cell and issuing an anomaly warning, the method further includes: Remove the faulty battery cell and decrement the serial number of each battery cell following the faulty one.

8. A device for monitoring batteries, characterized in that, An apparatus applicable to batteries comprising multiple cells, wherein the cells are pre-sorted according to their available capacity from smallest to largest, and assigned serial numbers; the cells are then divided into multiple cell groups according to a preset grouping rule, and the cell with the smallest serial number in each cell group is designated as the first cell; the apparatus includes: The first judgment module is used to monitor the balanced capacity of each of the cells and determine whether there are cells whose balanced capacity is greater than the rated allowable balanced capacity. The second judgment module is used to, if there is a cell with a balanced capacity greater than the rated allowable balanced capacity, take the first cell of the first group as the target cell, and determine whether there is a faulty cell in each of the remaining first cells based on the first balanced capacity of each of the first cells. The third judgment module is used to determine whether the faulty cell exists in the cell group where the first cell is located, based on the second equalization capacity of the other cells in the cell group where the first cell is located, if the faulty cell does not exist in any of the first cells. The early warning module is used to output the location of the faulty battery cell and issue an abnormality warning if the faulty battery cell is present in the battery cell group where the first battery cell is located. The balanced capacity is determined based on the difference between the available capacity of the battery cell and the reference capacity, where the reference capacity is the minimum available capacity among all the battery cells.

9. A battery management system, characterized in that, Includes the device for monitoring batteries as described in claim 8.

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