Method, device and electronic equipment for determining discharge time of battery cell

Abstract

The present invention discloses a method, device, and electronic device for determining the discharge duration of a battery cell. The method comprises: obtaining the respective power levels of multiple battery cells included in a power battery; determining a reference battery cell with the lowest power level from the multiple battery cells based on the respective power levels of the multiple battery cells; determining the power level differences between the power levels of the multiple battery cells and the power levels of the reference battery cell; determining a target battery cell from the multiple battery cells whose corresponding power level difference is greater than a first preset threshold; and determining a target discharge duration for the target battery cell based on the power level difference of the target battery cell. The present invention solves the technical problem in the related art of low total power reserve in a power battery after charging due to uneven power levels of multiple battery cells in the power battery.

Description

Technical Field

[0001] The present invention relates to the field of power batteries, and in particular, to a method, device and electronic equipment for determining the discharge duration of a battery cell. Background Art

[0002] As a key component of electric vehicles, power batteries' performance impacts both the vehicle's power and range. Power batteries consist of multiple cells connected in series and parallel, requiring individual cell management. However, prior art suffers from a low total power reserve after charging due to uneven charge distribution across multiple cells.

[0003] To address the above-mentioned problems, no effective solutions have been proposed so far. Summary of the Invention

[0004] Embodiments of the present invention provide a method, device, and electronic device for determining the discharge duration of a battery cell, to at least solve the technical problem in the related art of low total power reserve of a power battery after charging due to uneven power levels of multiple battery cells in the power battery.

[0005] According to one aspect of an embodiment of the present invention, a method for determining the discharge duration of a battery cell is provided, comprising: obtaining the respective electric quantities corresponding to a plurality of battery cells included in a power battery; determining a reference battery cell with the lowest electric quantity from the plurality of battery cells based on the respective electric quantities corresponding to the plurality of battery cells; determining the electric quantities corresponding to the plurality of battery cells, and the electric quantity differences between the electric quantities corresponding to the plurality of battery cells and the electric quantities corresponding to the reference battery cells; determining, from the plurality of battery cells, a target battery cell whose corresponding electric quantity difference is greater than a first preset threshold value; and determining a target discharge duration for discharging the target battery cell based on the electric quantity difference corresponding to the target battery cell.

[0006] Optionally, the target discharge time for the target battery cell is determined based on the charge difference corresponding to the target battery cell, including: determining a limited discharge time; determining an estimated discharge time corresponding to the target battery cell based on the charge difference corresponding to the target battery cell; and determining the target discharge time with a shorter time from the estimated discharge time and the limited discharge time.

[0007] Optionally, determining the estimated discharge time corresponding to the target battery cell based on the charge difference corresponding to the target battery cell includes: determining the maximum rated voltage of the target battery cell, the resistance value of the discharge resistor connected to the target battery cell, a predetermined current waveform coefficient, the rated maximum charge of the target battery cell, and the rated time; determining the ratio of the maximum rated voltage to the resistance value to obtain the maximum current; determining the product of the maximum current and the predetermined current waveform coefficient under the square root to obtain the target current value; determining the ratio of the charge difference corresponding to the target battery cell to the target current value to obtain the target ratio; determining the target ratio, the product of the rated maximum charge and the rated time to obtain the estimated discharge time corresponding to the target battery cell.

[0008] Optionally, before determining the target battery cell with the lowest battery charge from the multiple battery cells based on the respective battery charges corresponding to the multiple battery cells, the method further includes: eliminating the battery charges that are less than a second preset threshold value from the respective battery charges corresponding to the multiple battery cells, and obtaining multiple battery charges after eliminating the battery charges that are less than the second preset threshold value; and determining the target battery cell with the lowest battery charge from the multiple battery cells based on the multiple battery charges after eliminating the battery charges that are less than the second preset threshold value.

[0009] Optionally, after determining the target discharge time for discharging the target battery cell based on the power difference corresponding to the target battery cell, the method further includes: sending a discharge instruction to a discharge switch connected to the target battery cell, wherein the discharge instruction carries the target discharge time, and the discharge instruction is used to enable the discharge switch to turn on the discharge time to discharge the target battery cell.

[0010] Optionally, after obtaining the respective electric quantities corresponding to the multiple battery cells included in the power battery, the method further includes: determining, from the multiple battery cells, abnormal battery cells whose corresponding electric quantities are less than a second preset threshold value, or greater than a third preset threshold value, wherein the third preset threshold value is greater than the second preset threshold value; and sending abnormal information to a predetermined terminal, wherein the abnormal information carries the corresponding identifier of the abnormal battery cell and the electric quantity corresponding to the abnormal battery cell.

[0011] Optionally, obtaining the power corresponding to each of the multiple battery cells included in the power battery includes: when the power battery is in a charging state, determining the power calibration thresholds corresponding to each of the multiple battery cells; when the charging power corresponding to each of the multiple battery cells is greater than the corresponding power calibration threshold, determining a calibration cell from the multiple battery cells, wherein the calibration cell is a cell whose corresponding charging power is greater than the corresponding power calibration threshold; determining a change result of whether the charging power corresponding to the calibration cell changes within a predetermined time period; when the change result is that the charging power corresponding to the calibration cell does not change within the predetermined time period, determining a calibration ratio corresponding to the calibration cell, wherein the calibration ratio is the ratio of change when the charging power corresponding to the calibration cell is calibrated to a preset power; calibrating the charging power corresponding to each of the multiple battery cells according to the calibration ratio to obtain the power corresponding to each of the multiple battery cells.

[0012] According to one aspect of an embodiment of the present invention, a device for determining the discharge duration of a battery cell is provided, comprising: an acquisition module for acquiring the respective electric quantities corresponding to a plurality of battery cells included in a power battery; a first determination module for determining a reference battery cell with the lowest electric quantity from the plurality of battery cells based on the respective electric quantities corresponding to the plurality of battery cells; a second determination module for determining the electric quantities corresponding to the plurality of battery cells, and the electric quantity differences between the electric quantities corresponding to the plurality of battery cells and the electric quantities corresponding to the reference battery cells; a third determination module for determining, from the plurality of battery cells, a target battery cell whose corresponding electric quantity difference is greater than a first preset threshold value; and a fourth determination module for determining a target discharge duration for discharging the target battery cell based on the electric quantity difference corresponding to the target battery cell.

[0013] According to one aspect of an embodiment of the present invention, an electronic device is provided, comprising: a processor; and a memory for storing instructions executable by the processor; wherein the processor is configured to execute the instructions to implement any of the above methods for determining the discharge duration of a battery cell.

[0014] According to one aspect of an embodiment of the present invention, a computer-readable storage medium is provided, comprising: when the instructions in the computer-readable storage medium are executed by a processor of an electronic device, the electronic device is enabled to execute any of the above-mentioned methods for determining the discharge duration of a battery cell.

[0015] In an embodiment of the present invention, the power levels of multiple cells included in a power battery are obtained. Based on the power levels of the multiple cells, a reference cell with the lowest power level is determined from the multiple cells. The power levels of the multiple cells are then compared to the power levels of the reference cell. A target cell is then determined from the multiple cells, the target cell having a power level difference greater than a first preset threshold. This achieves the goal of determining a target discharge duration for the target cell based on the power level difference. By setting the first preset threshold, the target cell can be more effectively identified, allowing for more targeted discharge operations on the target cell, achieving power balance among the multiple cells. After the power levels of the multiple cells are balanced, all cells can be charged to near their maximum power levels when the power battery is charged again, resulting in a near-maximum total power reserve in the power battery. This solves the technical problem in the related art of low total power reserve in the power battery after charging due to unbalanced power levels among the multiple cells in the power battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 is a flow chart of a method for determining the discharge duration of a battery cell according to an embodiment of the present invention;

[0018] Figure 2 4 is a structural block diagram of a device for determining the discharge duration of a battery cell according to an embodiment of the present invention. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0020] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0021] Example 1

[0022] According to an embodiment of the present invention, an embodiment of a method for determining the discharge time of a battery cell is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0023] Figure 1 FIG. 1 is a flow chart of a method for determining the discharge duration of a battery cell according to an embodiment of the present invention. Figure 1 As shown, the method includes the following steps:

[0024] Step S102, obtaining the power corresponding to each of the multiple battery cells included in the power battery;

[0025] In step S102 provided in the present application, the above-mentioned power battery can be various types of power batteries such as lithium-ion batteries, nickel-metal hydride batteries and lead-acid batteries, which can be used in electric vehicles, hybrid systems, energy storage systems, and industrial equipment. There is no limitation here and customized settings can be made according to actual applications and scenarios.

[0026] The above-mentioned battery cells are the basic units that make up the above-mentioned power batteries. They can be different types of battery cells such as lithium-ion battery cells, nickel-metal hydride battery cells and lead-acid battery cells. There is no limitation here and they can be customized according to actual applications and scenarios.

[0027] It should be noted that the above implementation method can be applied in electric vehicles. The power battery can include multiple battery cells. The number of power batteries and the number of battery cells are not limited here and can be customized according to actual applications and scenarios.

[0028] For example, in an electric vehicle, when the power battery includes three cells A, B, and C, the power corresponding to the three cells A, B, and C is obtained.

[0029] Step S104, determining a reference cell with the lowest power from the multiple cells based on the power levels corresponding to the multiple cells;

[0030] In step S104 provided in the present application, the reference cell represents the cell with the lowest power among the multiple cells, and there may be only one reference cell.

[0031] For example, when there is only one battery cell with the lowest power, the power levels of the three battery cells A, B, and C are 60%, 70%, and 80% respectively. Then, from the power levels corresponding to the three battery cells A, B, and C, A is determined to be the battery cell with the lowest power, that is, A is the benchmark battery cell.

[0032] For example, when there are multiple cells with the lowest power, the power levels of cells A, B, C, D, and E are 60%, 70%, 80%, 60%, and 75% respectively. Then, cells A and D are determined to be the cells with the lowest power among cells A, B, C, D, and E. At this time, any one of cells A and D can be used as the basic cell.

[0033] Step S106, determining the power levels corresponding to the multiple battery cells and the power level differences between the power levels corresponding to the reference battery cell;

[0034] In step S106 provided in the present application, the power difference value represents the power difference value between the power corresponding to the battery cell and the power corresponding to the reference battery cell, that is, a corresponding power difference value is calculated for each battery cell.

[0035] For example, according to the previous implementation method, it has been determined that the power levels of the three battery cells A, B, and C are 60%, 70%, and 80% respectively, and the reference battery cell is A. At this time, the power levels of the three battery cells A, B, and C and the power level differences between them and the reference battery cell A are 0, 10%, and 20% respectively.

[0036] Step S108, determining a target battery cell whose corresponding power difference is greater than a first preset threshold value from the plurality of battery cells;

[0037] In step S108 provided in the present application, the above-mentioned first preset threshold is a fixed value set in advance for the power difference, which is not limited here and can be customized according to actual applications and scenarios. Then, based on the relative size of the power difference and the first preset threshold, the battery with a power difference greater than the first preset threshold can be determined as the target battery cell.

[0038] For example, when the number of battery cells is two, the target battery cell is one.

[0039] For example, the power levels of the two battery cells A and B are 80% and 70% respectively, the reference battery cell is B, the power differences between the power levels of the two battery cells A and B and the reference battery cell B are 10% and 0 respectively, the first preset threshold is set to 2%, and A is determined to be the target battery cell from the two battery cells A and B.

[0040] For example, when the number of battery cells is greater than two, the target battery cells are multiple.

[0041] For example, the power levels of the three battery cells A, B, and C are 60%, 70%, and 80% respectively, and the reference battery cell is A. The power levels of the three battery cells A, B, and C respectively correspond to the power levels of the reference battery cell A, and the power differences between them are 0, 10%, and 20% respectively. The first preset threshold is set to 2%, and B and C are determined as the target battery cells from the three battery cells A, B, and C.

[0042] It should be noted that in the process of determining the target battery cell, setting the first preset threshold value can more accurately identify the difference in power between multiple battery cells, thereby determining the battery cell that should be balanced, that is, the target battery cell, and the power that needs to be balanced for the battery cell to be balanced, so as to perform the discharge operation more accurately to achieve a better balancing effect.

[0043] In step S110 , a target discharge time for the target battery cell is determined according to the power difference corresponding to the target battery cell.

[0044] In step S110 provided in the present application, the target discharge duration is the time required for the target battery cell to release excess power. Since the method provided in the present application achieves a balancing effect by consuming the power of the battery cell through a power-consuming element. When the battery cell is connected to the power-consuming element, the battery cell consumes power. If the battery cell is always connected to the power-consuming element, the battery cell will continue to consume power, so it is necessary to set the target discharge duration for the target battery cell. This ensures that the target battery cell no longer consumes power after consuming a certain amount of power, and ultimately achieves a balance in power between multiple battery cells.

[0045] For example, according to the above-mentioned implementation method, it has been determined that among the two battery cells A and B, A is the target battery cell. At this time, the target battery cell A corresponds to a power difference. Therefore, the power difference corresponding to the target battery cell A corresponds to a target discharge time.

[0046] For example, according to the above-mentioned implementation method, among the three battery cells A, B, and C, B and C have been determined as the target battery cells. At this time, the target battery cell B and the target battery cell C each correspond to a power difference. Therefore, the power difference corresponding to the target battery cell B corresponds to a discharge time, and the power difference corresponding to the target battery cell C corresponds to a discharge time. At this time, there are two target discharge times, which are the discharge times of the corresponding target battery cells.

[0047] It should be noted that, through the target discharge time, the target battery cell can complete the discharge operation within the specified discharge time, reducing the difference in charge between multiple battery cells and achieving the purpose of charge balance among multiple battery cells.

[0048] Through steps S102-S110, the power levels of the multiple cells included in the power battery are obtained. Based on the power levels of the multiple cells, a reference cell with the lowest power level is determined from the multiple cells. The power levels of the multiple cells are then determined, and the power differences between the power levels of the multiple cells and the power levels of the reference cell are determined. A target cell is then determined from the multiple cells, whose power level differences are greater than a first preset threshold. This achieves the goal of determining a target discharge duration for the target cell based on the power level differences of the target cells. By setting the first preset threshold, the target cell can be more effectively identified, allowing for more targeted discharge operations on the target cell, achieving power balance among the multiple cells. After the power levels of the multiple cells are balanced, when the power battery is subsequently charged, all cells can be charged to near their maximum power levels, ensuring a near-maximum total power reserve in the power battery. This solves the technical problem in the related art of low total power reserve in the power battery after charging due to uneven power levels among the multiple cells in the power battery.

[0049] The above method of this embodiment is further introduced below.

[0050] As an optional embodiment, the target discharge time for the target battery cell is determined based on the power difference corresponding to the target battery cell, including: determining a limited discharge time; determining an estimated discharge time corresponding to the target battery cell based on the power difference corresponding to the target battery cell; and determining a shorter target discharge time from the estimated discharge time and the limited discharge time.

[0051] In this embodiment, the above-mentioned estimated discharge time is the estimated time required for the corresponding target battery cell to discharge. This time is calculated based on the charge difference corresponding to the target battery cell. The calculation of the estimated discharge time based on the charge difference can ensure that the charge of the target battery cell approaches the charge of the lowest battery cell through the estimated discharge time, so that the charge between multiple batteries is balanced. The relationship between the charge difference corresponding to the target battery cell and the estimated discharge time can be generally understood as follows: the larger the corresponding charge difference, the longer the corresponding estimated discharge time.

[0052] The above-mentioned discharge time limit is set to prevent the target cell from over-discharging or abnormal discharge due to an error in the estimated discharge time. Therefore, setting a discharge time limit helps prevent the target cell from over-discharging or abnormal discharge, thus avoiding unnecessary waste of energy.

[0053] The shorter of the estimated discharge time and the limited discharge time is determined as the target discharge time, which is the time required for the target cell to discharge. By selecting the target discharge time, over-discharge or abnormal discharge of the target cell can be avoided, and discharge can be carried out effectively, ultimately achieving a balanced charge.

[0054] As an optional embodiment, the estimated discharge time corresponding to the target battery cell is determined based on the charge difference corresponding to the target battery cell, including: determining the maximum rated voltage of the target battery cell, the resistance value of the discharge resistor connected to the target battery cell, the predetermined current waveform coefficient, the rated maximum charge of the target battery cell, and the rated time; determining the ratio of the maximum rated voltage to the resistance value to obtain the maximum current; determining the product of the maximum current and the predetermined current waveform coefficient under the square root to obtain the target current value; determining the ratio of the charge difference corresponding to the target battery cell to the target current value to obtain the target ratio; determining the target ratio, the product of the rated maximum charge and the rated time to obtain the estimated discharge time corresponding to the target battery cell.

[0055] In this embodiment, it can be noted that max is the maximum rated voltage of the target cell, R bal is the resistance value of the discharge resistor connected to the target cell, I Max Expressed as the maximum current; Expressed as the predetermined current waveform factor under the square root, I eff Expressed as the target current value, C is the rated maximum capacity of the target battery cell, and ΔSOC is the capacity difference corresponding to the target battery cell. The above process can be expressed as the following formula:

[0056]

[0057]

[0058]

[0059] In determining the target discharge time, the target current value must first be determined, and then the estimated discharge time is determined based on the target current value. Since the target current value can represent the actual state of charge of the target battery cell, that is, the actual discharge state can be better judged, thereby determining a more accurate estimated discharge time and ensuring a more balanced charge across multiple cells after discharge.

[0060] As an optional embodiment, before determining the target battery cell with the lowest battery power from the multiple battery cells based on the respective power levels corresponding to the multiple battery cells, it also includes: eliminating the power levels that are less than a second preset threshold value from the respective power levels corresponding to the multiple battery cells, to obtain multiple power levels after eliminating the power levels that are less than the second preset threshold value; and determining the target battery cell with the lowest battery power from the multiple battery cells based on the multiple power levels after eliminating the power levels that are less than the second preset threshold value.

[0061] In this embodiment, how to determine the target battery cell is described. Before determining the target battery cell with the lowest power, a second preset threshold power level can be determined first. The second set threshold can be set as a threshold that can measure whether the power level is abnormal. Then, the power levels less than the second preset threshold are eliminated from the power levels corresponding to the multiple battery cells, and the multiple power levels corresponding to the power levels less than the second preset threshold are determined after eliminating the power levels less than the second preset threshold. Since the eliminated power level is less than the second preset threshold, it can be determined that the power level is abnormal. In this case, the abnormal power level needs to be eliminated to avoid the phenomenon of disordered execution of the method provided in this application due to abnormal power level. Thus, based on the multiple power levels after eliminating the power levels less than the second preset threshold, the target battery cell with the lowest power level is determined from the multiple battery cells. By setting the second preset threshold, the abnormal power levels are eliminated, thereby eliminating the abnormal battery cells, and thus the target battery cells that meet the above conditions can be screened out from the normal and valid battery cells, and the target discharge time corresponding to the target battery cell can be determined more accurately to a certain extent.

[0062] As an optional embodiment, after determining the target discharge time for the target battery cell based on the power difference corresponding to the target battery cell, it also includes: sending a discharge instruction to a discharge switch connected to the target battery cell, wherein the discharge instruction carries the target discharge time, and the discharge instruction is used to turn on the discharge switch for the discharge time to discharge the target battery cell.

[0063] In this embodiment, the process of discharging the target battery cell is described according to the above method. After determining the discharge duration of the target battery cell, a discharge instruction carrying the target discharge duration is sent to a discharge switch connected to the target battery cell, so that the discharge switch receives the discharge instruction, closes the switch, connects the target battery cell to the power-consuming element, and starts the discharge process of the target discharge duration, so that the power-consuming element consumes the electricity in the target battery cell. By means of instructions, the switch can respond quickly, thereby speeding up the implementation process of the method of the present application.

[0064] As an optional embodiment, after obtaining the corresponding power levels of multiple battery cells included in the power battery, it also includes: determining, from the multiple battery cells, abnormal battery cells whose corresponding power levels are less than a second preset threshold, or greater than a third preset threshold, wherein the third preset threshold is greater than the second preset threshold; sending abnormal information to a predetermined terminal, wherein the abnormal information carries the corresponding identification of the abnormal battery cell and the power level corresponding to the abnormal battery cell.

[0065] In this embodiment, according to the above implementation method, it is also necessary to determine abnormal cells whose corresponding electric quantity is less than the second preset threshold value, and / or abnormal cells whose corresponding electric quantity is greater than the third preset threshold value from the electric quantities corresponding to the multiple cells.

[0066] The second preset threshold may be a set lower limit of power. For example, the power corresponding to the plurality of cells may be eliminated from the cells with power less than the lower limit. That is, the abnormal cell may be a cell with power less than the second preset threshold.

[0067] The third preset threshold may be a set upper limit of power, such as removing power greater than the upper limit from the power corresponding to a plurality of cells. That is, an abnormal cell may also be a cell with a power greater than the third preset threshold.

[0068] It should be noted that after an abnormal cell is identified, abnormal information can be sent to a predetermined terminal. The abnormal information carries an identifier corresponding to the abnormal cell and the corresponding power level of the abnormal cell. The identifier corresponding to the abnormal cell can be an identifier that can identify the location of the abnormal cell, so that the predetermined terminal can determine the location of the abnormal cell and the abnormal power level corresponding to the abnormal cell. This allows the work or operation and maintenance personnel using the predetermined terminal to promptly handle the abnormal cell and avoid the occurrence of more serious abnormal phenomena.

[0069] It should also be noted that after the abnormal battery cell is determined, the abnormal battery cell can be ignored in the subsequent execution of the method, and other normal battery cells can be subsequently processed to ensure the orderly execution of the method.

[0070] As an optional embodiment, obtaining the power corresponding to each of the multiple battery cells included in the power battery includes: when the power battery is in a charging state, determining the power calibration threshold values ​​corresponding to each of the multiple battery cells; when the charging power corresponding to each of the multiple battery cells is greater than the corresponding power calibration threshold value, determining a calibration cell from the multiple battery cells, wherein the calibration cell is a cell whose corresponding charging power is greater than the corresponding power calibration threshold value; determining a change result of whether the charging power corresponding to the calibration cell changes within a predetermined time period; when the change result is that the charging power corresponding to the calibration cell does not change within the predetermined time period, determining a calibration ratio corresponding to the calibration cell, wherein the calibration ratio is the ratio of change when the charging power corresponding to the calibration cell is calibrated to a preset power; calibrating the charging power corresponding to the multiple battery cells according to the calibration ratio to obtain the power corresponding to the multiple battery cells.

[0071] In this embodiment, when the power battery is in a charging state, before determining the power levels corresponding to the multiple battery cells, there may be a problem of inaccurate display of the power levels corresponding to the multiple battery cells. That is, when the power level corresponding to a certain battery cell reaches 95%, it may no longer continue to rise. Therefore, it can be judged that the power level corresponding to the battery cell should be 100% full at this time, not 95%, so power calibration is required.

[0072] In this case, it is necessary to determine whether the power levels corresponding to the multiple battery cells need to be calibrated. Therefore, a power calibration threshold can be set for each of the multiple battery cells. Among the power levels corresponding to the multiple battery cells, a battery cell with a power level greater than the corresponding power calibration threshold can be identified, i.e., a calibration cell, to determine whether the multiple battery cells included in the power battery need to be calibrated. The determination of whether calibration is necessary can be made by determining whether the charge level corresponding to the calibration cell changes within a predetermined time period. If the charge level does not change, it indicates that the battery is actually fully charged and the charge level needs to be adjusted to full power. The charge levels corresponding to the other battery cells also need to increase proportionally. Therefore, if the change result shows that the charge level corresponding to the calibration cell does not change within the predetermined time period, the charge level corresponding to the calibration cell needs to be calibrated to a calibration ratio that changes when the preset power level is reached. The charge levels corresponding to the multiple battery cells are then calibrated according to the calibration ratio to obtain the charge levels corresponding to the multiple battery cells. This makes the charge levels corresponding to the multiple battery cells more accurate, thereby enabling more efficient subsequent processing.

[0073] Based on the above embodiment and optional embodiment, an optional implementation manner is provided, which is described in detail below.

[0074] In the related art, there is a technical problem of low total power reserve of the power battery after charging. For example, in the related art, the battery cells use the voltage method to balance the battery cell power. In this process, the length of the discharge time is not taken into consideration. It is ignored that when the discharge time is too long or too short, when the battery cell power is overcharged or over-discharged, there will be serious differences in the power between the battery cells, resulting in low total power reserve of the power battery after charging.

[0075] In view of this, a method for determining the discharge time of a battery cell is provided in an optional embodiment of the present invention, and the optional embodiment of the present application is described in detail below.

[0076] S1. Obtain the power levels of the two cells A and B in the electric vehicle, which are 85% and 90% respectively;

[0077] It should be noted that before obtaining the power corresponding to the two battery cells A and B included in the power battery, the power corresponding to the two battery cells A and B is calibrated to obtain the calibrated power. The calibrated power is the power corresponding to the calibration ratio of multiple battery cells in the charging state. The calibrated power can be calibrated using a dynamic calibration point necessary algorithm. The specific implementation process is as follows:

[0078] (1) Setting a power calibration threshold and determining whether the power calibration threshold is reached during charging;

[0079] (2) Determine the cell whose electric quantity is greater than the corresponding electric quantity calibration threshold from the electric quantities corresponding to the two cells A and B, and obtain the calibration cell;

[0080] (3) obtaining a relative ratio of the charged power corresponding to the calibration cell to the preset power corresponding to the calibration cell, wherein the relative ratio is a calibration ratio;

[0081] (4) If the charging capacity corresponding to the calibration cell does not change within the predetermined time, the charging capacity corresponding to the two cells A and B is calibrated according to the calibration ratio.

[0082] S2. In the above example, the corresponding power levels of the two cells A and B are 85% and 95% respectively, so the reference cell A is determined;

[0083] S3. Based on the above example, the power levels of cells A and B are 85% and 95% respectively, and the power level of the reference cell A is determined to be 0 and 5% respectively.

[0084] S4, a target cell where the difference between the power corresponding to each of the two cells A and B and the power corresponding to the reference cell A is greater than a first preset threshold;

[0085] As in the above example, the power levels of the two battery cells A and B are 85% and 95% respectively, and the power difference of the reference battery cell A is 0.5%. At this time, the first preset threshold value can be set to 2%, and from the two battery cells A and B, the battery cell with a power difference greater than the first preset threshold value is determined to be the B battery cell, that is, the B battery cell is the target battery cell.

[0086] S5. Determine the discharge time of battery cell B based on the power difference corresponding to battery cell B;

[0087] It should be noted that before calculating the discharge time of battery cell B, it is necessary to first determine the estimated discharge time of battery cell B. The specific implementation process is as follows:

[0088] (1) Determine the target current value. The specific formula is as follows:

[0089]

[0090]

[0091] In the above formula (1), U max is the maximum rated voltage of cell B, R bal is the resistance value of the discharge resistor connected to cell B, I Max is the maximum current; in the above formula (2), is the predetermined current waveform coefficient under the square root, I eff is the target current value.

[0092] (2) Determine the estimated discharge time based on the target current value. The specific calculation formula is as follows:

[0093]

[0094] In the above formula (3), ΔSOC n is the power difference corresponding to cell B, and C is the rated maximum power of the target cell.

[0095] (3) Set the limit discharge time, and determine the target discharge time T based on the estimated discharge time, the set limit discharge time and the remaining time after the estimated discharge time starts. min , the specific calculation process is as follows:

[0096] T min =min{T est， T set ,T store};

[0097] The above T est , is the estimated discharge time, T set , to limit the discharge time, T storeThe time remaining after the discharge starts based on the estimated discharge duration.

[0098] S6: Send a discharge instruction to the discharge switch connected to the B battery cell, wherein the discharge instruction carries a target discharge time. The discharge instruction is used to turn on the discharge switch for the discharge time to discharge the B battery cell, reducing the charge of the B battery cell from 90% to 85%, thereby achieving charge balance between the battery cells.

[0099] Through the above optional implementation, at least the following beneficial effects can be achieved:

[0100] (1) Since a target cell having a power difference greater than a first preset threshold value is determined from the power differences corresponding to the plurality of cells, that is, by setting the first preset threshold value, not only can the target cell be determined more effectively and accurately, but the target cell can also be discharged in a more targeted manner to balance the power among the plurality of cells;

[0101] (2) In the process of determining the target discharge time, the estimated discharge time must be determined first, and the estimated discharge time is calculated by the power difference corresponding to the target battery cell. The calculation of the estimated discharge time by the power difference can ensure that the power of the target battery cell approaches the power of the minimum battery cell through the estimated discharge time, so that the power between multiple battery cells is balanced.

[0102] It should be noted that for the aforementioned method embodiments, for simplicity of description, they are all expressed as a series of action combinations. However, those skilled in the art should be aware that the present invention is not limited by the order of the actions described, because according to the present invention, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in this specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0103] Through the description of the above embodiments, those skilled in the art can clearly understand that the method according to the above embodiment can be implemented by means of software plus the necessary general hardware platform, and of course it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a number of instructions for enabling a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods of various embodiments of the present invention.

[0104] Example 2

[0105] According to an embodiment of the present invention, a device for implementing the above-mentioned method for determining the discharge duration of a battery cell is also provided. Figure 2 is a structural block diagram of a device for determining the discharge duration of a battery cell according to an embodiment of the present invention. Figure 2 As shown, the device includes: an acquisition module 202, a first determination module 204, a second determination module 206, a third determination module 208 and a fourth determination module 210. The device will be described in detail below.

[0106] An acquisition module 202 is used to obtain the respective electric quantities corresponding to the multiple battery cells included in the power battery; a first determination module 204 is used to determine a reference battery cell with the lowest electric quantity from the multiple battery cells based on the respective electric quantities corresponding to the multiple battery cells; a second determination module 206 is used to determine the electric quantities corresponding to the multiple battery cells, and the difference between the electric quantities corresponding to the reference battery cells; a third determination module 208 is used to determine, from the multiple battery cells, a target battery cell whose corresponding electric quantity difference is greater than a first preset threshold value; and a fourth determination module 210 is used to determine a target discharge time for discharging the target battery cell based on the electric quantity difference corresponding to the target battery cell.

[0107] It should be noted here that the above-mentioned acquisition module 202, first determination module 204, second determination module 206, third determination module 208 and fourth determination module 210 correspond to steps S102 to S110 in the method for determining the discharge time of the battery cell. The examples and application scenarios implemented by the multiple modules and the corresponding steps are the same, but are not limited to the contents disclosed in the above-mentioned embodiment 1.

[0108] Example 3

[0109] According to another aspect of an embodiment of the present invention, an electronic device is provided, comprising: a processor; and a memory for storing instructions executable by the processor, wherein the processor is configured to execute the instructions to implement any of the above methods for determining the discharge duration of a battery cell.

[0110] Example 4

[0111] According to another aspect of an embodiment of the present invention, a computer-readable storage medium is also provided. When the instructions in the computer-readable storage medium are executed by a processor of an electronic device, the electronic device can execute any of the above-mentioned methods for determining the discharge time of a battery cell.

[0112] The serial numbers of the above embodiments of the present invention are for description only and do not represent the advantages or disadvantages of the embodiments.

[0113] In the above embodiments of the present invention, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0114] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only exemplary. For example, the division of the units can be a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0115] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0116] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0117] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk.

[0118] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for determining the discharge time of a battery cell, characterized in that: include: Obtaining the power corresponding to each of the multiple cells included in the power battery; Determining a reference battery cell with the lowest power among the multiple battery cells according to the power levels corresponding to the multiple battery cells; Determine the power levels corresponding to the plurality of battery cells, and the power differences between the power levels corresponding to the reference battery cell; Determine, from the plurality of battery cells, a target battery cell whose corresponding battery charge difference is greater than a first preset threshold; Determining a target discharge time for the target battery cell based on the power difference corresponding to the target battery cell; Wherein, the obtaining of the power amounts corresponding to the multiple battery cells included in the power battery includes: when the power battery is in a charging state, determining the power amount calibration thresholds corresponding to the multiple battery cells; when the charging power amounts corresponding to the multiple battery cells are greater than the corresponding power amount calibration thresholds, determining a calibration cell from the multiple battery cells, wherein the calibration cell is a cell whose corresponding charging power amount is greater than the corresponding power amount calibration threshold; determining a change result of whether the charging power amount corresponding to the calibration cell changes within a predetermined time period; when the change result is that the charging power amount corresponding to the calibration cell does not change within the predetermined time period, determining a calibration ratio corresponding to the calibration cell, wherein the calibration ratio is the ratio of change when the charging power amount corresponding to the calibration cell is calibrated to a preset power amount; calibrating the charging power amounts corresponding to the multiple battery cells according to the calibration ratio to obtain the power amounts corresponding to the multiple battery cells.

2. The method according to claim 1, characterized in that The step of determining a target discharge time for the target battery cell based on the power difference corresponding to the target battery cell includes: Determine the limit discharge time; Determining an estimated discharge time corresponding to the target battery cell based on the power difference corresponding to the target battery cell; The target discharge duration, which is shorter, is determined from the estimated discharge duration and the limited discharge duration.

3. The method according to claim 2, characterized in that The step of determining an estimated discharge time corresponding to the target battery cell according to the power difference corresponding to the target battery cell includes: Determining the maximum rated voltage of the target battery cell, the resistance value of the discharge resistor connected to the target battery cell, a predetermined current waveform factor, the rated maximum capacity of the target battery cell, and the rated duration; Determine the ratio of the maximum rated voltage to the resistance value to obtain the maximum current; Determine the product of the maximum current value and the predetermined current waveform coefficient under the square root to obtain a target current value; Determine the ratio of the power difference corresponding to the target battery cell to the target current value to obtain a target ratio; The target ratio is determined, and the product of the rated maximum power and the rated duration is multiplied to obtain the estimated discharge duration corresponding to the target battery cell.

4. The method according to claim 1, wherein The step of determining a target battery cell with the lowest power among the multiple battery cells based on the power corresponding to the multiple battery cells respectively includes: Eliminating the electric quantities less than a second preset threshold from the electric quantities corresponding to the multiple battery cells, to obtain multiple electric quantities after excluding the electric quantities less than the second preset threshold; The target battery cell with the lowest battery power is determined from the multiple battery cells based on the multiple battery power levels after excluding the battery power levels that are less than the second preset threshold.

5. The method according to claim 1, wherein After determining the target discharge time of the target battery cell according to the power difference corresponding to the target battery cell, the method further includes: A discharge instruction is sent to a discharge switch connected to the target battery cell, wherein the discharge instruction carries the target discharge duration, and the discharge instruction is used to turn on the discharge switch for the discharge duration to discharge the target battery cell.

6. The method according to claim 1, wherein After obtaining the power quantities corresponding to the plurality of cells included in the power battery, the method further includes: Determining, from the plurality of battery cells, abnormal battery cells whose corresponding electric quantity is less than a second preset threshold value, or greater than a third preset threshold value, wherein the third preset threshold value is greater than the second preset threshold value; Sending abnormal information to a predetermined terminal, wherein the abnormal information carries the corresponding identifier of the abnormal battery cell and the power corresponding to the abnormal battery cell.

7. A device for determining the discharge time of a battery cell, characterized in that: include: An acquisition module is used to obtain the power corresponding to each of the multiple cells included in the power battery; A first determining module is configured to determine a reference battery cell with the lowest power among the multiple battery cells based on the power corresponding to the multiple battery cells respectively; A second determining module is used to determine the power differences between the power corresponding to each of the plurality of battery cells and the power corresponding to the reference battery cell; A third determining module is configured to determine, from the plurality of battery cells, a target battery cell whose corresponding power difference is greater than a first preset threshold; A fourth determining module is configured to determine a target discharge time for discharging the target battery cell according to the power difference corresponding to the target battery cell; Wherein, the acquisition module is further used to determine the power calibration thresholds corresponding to the multiple battery cells when the power battery is in a charging state; when the charging power corresponding to the multiple battery cells is greater than the corresponding power calibration threshold, determine the calibration battery cell from the multiple battery cells, wherein the calibration battery cell is a battery cell whose corresponding charging power is greater than the corresponding power calibration threshold; determine the change result of whether the charging power corresponding to the calibration battery cell changes within a predetermined time period; when the change result is that the charging power corresponding to the calibration battery cell does not change within the predetermined time period, determine the calibration ratio corresponding to the calibration battery cell, wherein the calibration ratio is the ratio of change when the charging power corresponding to the calibration battery cell is calibrated to a preset power; calibrate the charging power corresponding to the multiple battery cells according to the calibration ratio to obtain the power corresponding to the multiple battery cells.

8. An electronic device, characterized in that: include: processor; a memory for storing instructions executable by the processor; The processor is configured to execute the instructions to implement the method for determining the discharge duration of a battery cell according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that When the instructions in the computer-readable storage medium are executed by a processor of an electronic device, the electronic device is enabled to execute the method for determining the discharge duration of a battery cell as claimed in any one of claims 1 to 6.

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