Balanced state detection method, detection device, detection system and storage medium

Abstract

The invention discloses an equilibrium state detection method, an equilibrium state detection device, an equilibrium state detection system and a computer readable storage medium. The equalization state detection method comprises the steps of judging whether a battery pack meets a standing equalization condition or not; when the battery pack meets the standing equalization condition, acquiring standing equalization time information and voltage information of each battery cell in the battery pack; and determining the actual equilibrium state of the battery cell based on the time information and the voltage information. Thus, the actual equalization state of the battery cell can be effectively detected, the execution effect of the equalization instruction is verified through the actual equalization state of the battery cell, identification of the actual equalization state of the battery cell under various working conditions can be covered, and the system safety of the battery pack is improved.

Description

Technical Field

[0001] The present application relates to the technical field of battery equalization, and in particular to a method for detecting a balanced state, a device for detecting a balanced state, a system for detecting a balanced state, and a computer-readable storage medium. Background Art

[0002] In the Battery Management System (BMS), the diagnosis of the balanced state of the battery cells in the battery pack is a key link to ensure the stable performance of the battery pack, extend the service life and improve the system safety. Therefore, how to effectively detect the actual balanced state of the battery cells has become an urgent problem to be solved. Summary of the invention

[0003] The embodiments of the present application provide a balanced state detection method, a balanced state detection device, a balanced state detection system and a computer-readable storage medium to solve at least one of the above-mentioned technical problems.

[0004] The equilibrium state detection method of the embodiment of the present application includes:

[0005] Determine whether the battery pack meets the static balancing conditions;

[0006] When the battery pack meets the static balancing condition, acquiring static balancing time information and voltage information of each battery cell in the battery pack;

[0007] An actual balancing state of the battery cell is determined based on the time information and the voltage information.

[0008] In some embodiments, the equilibrium state detection method further includes:

[0009] Obtaining cell parameters of the plurality of cells in the battery pack;

[0010] Performing consistency judgment on the plurality of battery cells according to the battery cell parameters to determine the balancing requirement of each battery cell;

[0011] Sending a balancing instruction to the corresponding battery cell according to the balancing requirement;

[0012] After sending the balancing instruction to the corresponding battery cell according to the balancing requirement, the step of determining whether the battery pack meets the static balancing condition is performed.

[0013] In some embodiments, determining whether the battery pack meets the static balancing condition includes:

[0014] If the battery pack stops charging and discharging and continues to reach a calibrated time threshold, and the maximum change value of the cell voltage of the plurality of cells in the battery pack is less than a predetermined voltage threshold within a predetermined time period, it is determined that the battery pack meets the static balancing condition;

[0015] Otherwise, it is determined that the battery pack does not meet the static balancing condition.

[0016] In some embodiments, when the battery pack meets the static balancing condition, obtaining the static balancing time information and voltage information of each battery cell in the battery pack includes:

[0017] When the battery pack meets the static balancing condition, obtaining the starting time, starting voltage, current time and current voltage of each battery cell for static balancing;

[0018] The determining the actual balanced state of the battery cell based on the time information and the voltage information includes:

[0019] Determine a current voltage difference and a current balancing capacity according to the start time, the start voltage, the current time and the current voltage;

[0020] An actual balancing state of the battery cell is determined based on the current voltage difference and the current balancing capacity.

[0021] In some embodiments, determining the current voltage difference and the current balancing capacity according to the start time, the start voltage, the current time, and the current voltage includes:

[0022] Calculating the current voltage difference according to the starting voltage and the current voltage;

[0023] The current balancing capacity is calculated according to the current voltage, the start time and the current time.

[0024] In some embodiments, determining the actual balancing state of the battery cell based on the current voltage difference and the current balancing capacity includes:

[0025] Obtaining the current state of charge of each of the battery cells;

[0026] determining an expected voltage difference according to the current state of charge and the current equalization capacity;

[0027] An actual balanced state of the battery cell is determined based on the current voltage difference and the expected voltage difference.

[0028] In some embodiments, determining the actual balanced state of the battery cell based on the current voltage difference and the expected voltage difference includes:

[0029] Determining whether the expected voltage difference is greater than the sum of a preset voltage constant of the current state of charge and a predetermined influencing factor;

[0030] When the expected voltage difference is greater than the sum of the preset voltage constant and the predetermined influencing factor, the actual balanced state of the battery cell is determined according to the current voltage difference.

[0031] In some embodiments, when the expected voltage difference is greater than the sum of the preset voltage constant and the predetermined influencing factor, determining the actual balanced state of the battery cell according to the current voltage difference includes:

[0032] When the expected voltage difference is greater than the sum of the preset voltage constant and the predetermined influencing factor, determining whether the current voltage difference is greater than the preset voltage constant;

[0033] If the current voltage difference is greater than the preset voltage constant, it is determined that the cell balancing is normal;

[0034] If the current voltage difference is less than the preset voltage constant, it is determined that the cell balancing is abnormal.

[0035] The equilibrium state detection device of the embodiment of the present application includes:

[0036] A judgment module, used to judge whether the battery pack meets the static balancing condition;

[0037] An acquisition module, used for acquiring time information and voltage information of static equalization of each battery cell in the battery pack when the battery pack meets the static equalization condition;

[0038] A determination module is used to determine an actual balancing state of the battery cell based on the time information and the voltage information.

[0039] The equilibrium state detection system of the embodiment of the present application includes one or more processors and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, the equilibrium state detection method of any of the above embodiments is implemented.

[0040] The computer-readable storage medium of the embodiment of the present application stores a computer program thereon, and when the program is executed by a processor, the equilibrium state detection method of any of the above-mentioned embodiments is implemented.

[0041] The balanced state detection method, balanced state detection device, balanced state detection system and computer-readable storage medium of the embodiment of the present application obtain the time information and voltage information of each battery cell in the battery pack during the static balanced state when the battery pack meets the static balanced condition, and determine the actual balanced state of the battery cell based on the time information and voltage information. In this way, the actual balanced state of the battery cell can be effectively detected, so as to verify the execution effect of the balanced instruction through the actual balanced state of the battery cell, and can cover the recognition of the actual balanced state of the battery cell under various working conditions, thereby improving the system safety of the battery pack.

[0042] Additional aspects and advantages of the embodiments of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0044] Figure 1 is a flow chart of a method for detecting a balanced state in certain embodiments of the present application;

[0045] Figure 2 It is a schematic diagram of the working process of the equilibrium state detection method of certain embodiments of the present application;

[0046] Figure 3 is a flow chart of a method for detecting a balanced state in certain embodiments of the present application;

[0047] Figure 4 is a flow chart of a method for detecting a balanced state in certain embodiments of the present application;

[0048] Figure 5 is a flow chart of a method for detecting a balanced state in certain embodiments of the present application;

[0049] Figure 6 is a flow chart of a method for detecting a balanced state in certain embodiments of the present application;

[0050] Figure 7 is a flow chart of a method for detecting a balanced state in certain embodiments of the present application;

[0051] Figure 8 It is a schematic diagram of static balanced pressure difference of the battery cell OCV curve in certain embodiments of the present application;

[0052] Fig. 9 is a flow chart of a method for detecting a balanced state in certain embodiments of the present application;

[0053] Fig.10is a flow chart of a method for detecting a balanced state in certain embodiments of the present application;

[0054] Fig.11 is a module schematic diagram of an equilibrium state detection device of certain embodiments of the present application;

[0055] Fig.12 is a module schematic diagram of an equilibrium state detection system of certain embodiments of the present application;

[0056] Fig.13 It is a schematic diagram of the connection status between a computer-readable storage medium and a processor in certain embodiments of the present application.

[0057] Description of reference numerals:

[0058] Balanced state detection device 100 , judgment module 10 , acquisition module 20 , determination module 30 , sending module 40 , balanced state detection system 200 , processor 210 , memory 220 , computer readable storage medium 300 , computer program 310 , processor 320 . DETAILED DESCRIPTION

[0059] The following is a further description of the embodiments of the present application in conjunction with the accompanying drawings. The same or similar reference numerals in the accompanying drawings represent the same or similar elements or elements with the same or similar functions from beginning to end. In addition, the embodiments of the present application described below in conjunction with the accompanying drawings are exemplary and are only used to explain the embodiments of the present application, and cannot be understood as limiting the present application.

[0060] See also Figure 1 and Figure 2 , the equilibrium state detection method of the embodiment of the present application includes:

[0061] 010: Determine whether the battery pack meets the static balancing conditions;

[0062] 020: When the battery pack meets the static balancing condition, obtain the static balancing time information and voltage information of each cell in the battery pack;

[0063] 030: Determine the actual balancing state of the battery cell based on the time information and the voltage information.

[0064] The method for detecting the balancing state of the embodiment of the present application obtains the time information and voltage information of the balancing state of each battery cell in the battery pack when the battery pack meets the static balancing condition, and determines the actual balancing state of the battery cell based on the time information and voltage information. In this way, the actual balancing state of the battery cell can be effectively detected, so as to verify the execution effect of the balancing instruction through the actual balancing state of the battery cell, and can cover the recognition of the actual balancing state of the battery cell under various working conditions, thereby improving the system safety of the battery pack.

[0065] It can be understood that the battery management controller obtains the voltage of each battery cell in the battery pack in real time through the acquisition module, and diagnoses and determines whether the current battery pack needs to be balanced. If balancing is required, the balancing control module executes the on and off of the balancing switch by sending the balancing instruction of the corresponding channel.

[0066] However, in the actual operation of the battery management system, various situations may be encountered, resulting in the balancing instructions of the corresponding channel sent by the battery management controller being inconsistent with the actual balancing status of the battery cells in the battery pack. For example, the controller sends the command sequence to the balancing control module through the communication bus incorrectly, data transmission errors, balancing control chip abnormalities, balancing channel circuit abnormalities, etc. These reasons will cause the balancing control module to fail to correctly execute the corresponding balancing instructions, thereby deteriorating the consistency of the battery cells in the battery pack, reducing the battery pack performance, and reducing the vehicle's cruising range. In severe cases, it may affect the safety of the battery pack.

[0067] In the related art, the current equilibrium state is mainly determined by the method of voltage backchecking of the equilibrium channel, but this method has the risk of backcheck failure. If an additional redundant backcheck circuit is added, the circuit complexity will increase, and the increase in circuit complexity will further increase the failure rate of the circuit, and also increase the product cost.

[0068] In the implementation mode of the present application, when the battery pack meets the static balancing conditions, the time information and voltage information of each battery cell in the battery pack are obtained, and the actual balancing state of the battery cell is determined based on the time information and voltage information. In this way, the actual balancing state of the battery cell can be effectively detected, so as to verify the execution effect of the balancing instruction through the actual balancing state of the battery cell, and can completely cover a series of balancing execution abnormalities such as abnormalities in the transmission of balancing instructions, abnormal balancing switch control, and abnormal balancing circuit backcheck, so as to realize the identification of the actual balancing state of the battery cell under various working conditions and improve the system safety of the battery pack.

[0069] See also Figure 3 In some embodiments, the equilibrium state detection method further includes:

[0070] 040: Get the cell parameters of multiple cells in the battery pack;

[0071] 050: Perform consistency judgment on multiple cells based on cell parameters to determine the balancing requirements of each cell;

[0072] 060: Send balancing instructions to the corresponding battery cells according to balancing requirements;

[0073] After sending a balancing instruction to the corresponding battery cell according to the balancing requirement (ie 060), a step of determining whether the battery pack meets the static balancing condition (ie 010) is performed.

[0074] Specifically, the battery pack may be a lithium battery pack in a vehicle. Obtain the cell parameters of multiple cells in the battery pack. The cell parameters may include cell voltage, cell temperature, cell current, cell static state, etc. The cell parameters may reflect the current state and health of the cell. By making consistency judgments on multiple cells based on the cell parameters, the performance differences and consistency between the cells can be evaluated, thereby determining the balancing requirements of each cell. For example, determine which cells need to be balanced, as well as the priority and degree of balancing.

[0075] In some examples, the cell parameters include cell voltages. Obtain the cell voltages U1, U2, U3...Un of multiple cells, and make consistency judgments on the multiple cells according to the cell voltages U1, U2, U3...Un, that is, voltage consistency judgments, to determine the balancing requirements of each cell. After determining the balancing requirements, send balancing instructions to the corresponding cells to perform balancing operations to reduce the voltage differences between the cells. Among them, the balancing instructions may include parameters such as balancing mode (such as active balancing or passive balancing), balancing current size, and balancing time.

[0076] In the implementation mode of the present application, the step of judging whether the battery pack meets the static balancing condition (i.e., 010) is performed after sending a balancing instruction (i.e., 060) to the corresponding battery cell according to the balancing requirement. In this way, the battery management system has performed the corresponding balancing operation, and then judging whether the battery pack meets the static balancing condition can make an effective judgment, thereby reducing the energy loss caused by the continuous judgment of the system. When the balancing instruction has not been sent to the corresponding battery cell according to the balancing requirement, there is no need to judge whether the battery pack meets the static balancing condition, and obtain time information and voltage information to determine the actual balancing state of the battery cell.

[0077] See also Figure 4 In some embodiments, determining whether the battery pack meets the static balancing condition (ie, 010) includes:

[0078] 011: If the battery pack stops charging and discharging and continues to reach the calibration time threshold, and the maximum change value of the cell voltage of multiple cells in the battery pack is less than the predetermined voltage threshold within the predetermined time period, it is determined that the battery pack meets the static balancing condition;

[0079] 012: Otherwise, it is determined that the battery pack does not meet the static balancing conditions.

[0080] Specifically, the logic of the embodiment of the present application for judging whether the battery pack meets the static balancing condition is as follows. First, the battery pack stops charging and discharging, that is, the high voltage of the battery pack is disconnected, and the battery pack is not currently performing charging or discharging operations. Second, after the battery pack stops charging and discharging, it needs to continue for a period of time, and this time needs to reach the preset calibration time threshold T1. Third, the maximum change value max(ΔV[i]) of the cell voltage of multiple cells in the battery pack needs to be less than the predetermined voltage threshold ΔVthrd within the continuous predetermined time period T2. Among them, the predetermined time period T2 can be a sub-time period within the calibration time threshold T1. If all of the above conditions are met, it means that the battery pack meets the static balancing condition. Otherwise, if any condition is not met, it means that the battery pack does not meet the static balancing condition. The above conditions can ensure that the battery pack has been statically balanced, so that based on the acquired static balancing time information and voltage information of each cell, the actual balancing state of the cell will be determined more accurately.

[0081] In some examples, the calibration time threshold T1 is ≥ 10 minutes. The predetermined time period T2 may be 3S. The voltage threshold ΔVthrd is ≤ 4mV. Wherein, i is the number of the balancing channel corresponding to the i-th battery cell or the i-th battery cell, 1 ≤ i ≤ n, and n is the total number of batteries.

[0082] It should be noted that the calibration time threshold T1 is not equivalent to the duration of the cell voltage equalization, but after the vehicle is used, the calibration time threshold T1 is waited for so that the cell can be completely static. The cell voltage can be equalized immediately after the vehicle is used, but the calibration time threshold T1 needs to be waited for to meet the static equalization condition before the equalization effect is detected and the subsequent equalization state is determined, so as to effectively detect the actual balanced state of the cell.

[0083] See also Figure 5 In some embodiments, when the battery pack meets the static balancing condition, obtaining the static balancing time information and voltage information of each battery cell in the battery pack (ie, 020) includes:

[0084] 021: When the battery pack meets the static balancing conditions, obtain the starting time, starting voltage, current time and current voltage of each cell;

[0085] Determine the actual balancing state of the cell (i.e. 030) based on the time information and the voltage information, including:

[0086] 031: Determine the current voltage difference and the current balancing capacity according to the start time, the start voltage, the current time and the current voltage;

[0087] 032: Determine the actual balancing state of the battery cell based on the current voltage difference and the current balancing capacity.

[0088] Specifically, when the battery pack meets the static balancing conditions, the battery management controller will record the start time and start voltage of each cell's static balancing, as well as the current time and current voltage at each moment. Among them, the start time can be counted from the time the aforementioned calibration time threshold T1 is reached, and the time at this time is used as the start time of the cell's static balancing. The voltage sampled by the cell at the start time is the start voltage, represented by Vs(i). The voltage sampled by the cell at the current time is the current voltage, represented by Vr(i).

[0089] According to the start time, the start voltage Vs(i), the current time and the current voltage Vr(i), the current voltage difference ΔVr(i) and the current balancing capacity ΔQ(i) can be determined to accurately evaluate the actual balancing state of each battery cell.

[0090] In the implementation mode of the present application, the battery management controller can be in a dormant state or a timed awakening state, so as not to affect the operation of other controller nodes on the vehicle bus, and at the same time, it can also reduce the energy loss caused by the continuous operation of the controller. When the battery pack meets the static balancing conditions, the battery management controller is awakened to record the starting time, starting voltage, current time and current voltage of each battery cell; or the battery management control will also be awakened regularly to record the time information and voltage information of each battery cell, so that when the battery pack meets the static balancing conditions, the starting time, starting voltage, current time and current voltage of each battery cell can be obtained.

[0091] See also Figure 6 In some embodiments, determining the current voltage difference and the current balancing capacity (ie, 031) according to the start time, the start voltage, the current time, and the current voltage includes:

[0092] 0311: Calculate the current voltage difference based on the starting voltage and the current voltage;

[0093] 0312: Calculate the current balancing capacity based on the current voltage, start time and current time.

[0094] Specifically, the current voltage difference ΔVr(i) can be calculated according to the starting voltage Vs(i) and the current voltage Vr(i), and the specific calculation method is as follows:

[0095] ΔVr(i)=Vr(i)-Vs(i);

[0096] The current balancing capacity ΔQ(i) can be calculated based on the current voltage Vr(i), the start time and the current time. The specific calculation method is as follows:

[0097] ΔQ(i)=∑Vr(i) / Rb*Δt;

[0098] Among them, Vr(i) is the current voltage of the i-th battery cell sampled at the current time; Rb is the resistance of the balancing channel, each balancing channel resistance is the same and can be measured in advance; Δt is the unit balancing time, and the total cumulative summation time can be determined based on the current time and the start time.

[0099] See also Figure 7 In some embodiments, determining the actual balancing state of the battery cell based on the current voltage difference and the current balancing capacity (ie, 032) includes:

[0100] 0321: Get the current state of charge of each battery cell;

[0101] 0322: Determine the expected voltage difference based on the current state of charge and the current equalization capacity;

[0102] 0323: Determine the actual balance state of the battery cell based on the current voltage difference and the expected voltage difference.

[0103] Specifically, when determining the actual balancing state of the battery cell based on the current voltage difference and the current balancing capacity, the current state of charge SOC(i) of each battery cell can be obtained first, and then the expected voltage difference ΔVe(i) is determined according to the current state of charge SOC(i) and the current balancing capacity ΔQ(i), and finally the actual balancing state of the battery cell is determined based on the current voltage difference ΔVr(i) and the expected voltage difference ΔVe(i).

[0104] See also Figure 8 , Figure 8 The static equilibrium pressure difference diagram of the cell OCV curve is shown in Figure 1. The OCV curve can be obtained in advance through experiments during the development phase. The specific acquisition method is as follows: the cell is in a completely static state, the voltage and SOC of the cell are obtained at each moment, and a corresponding relationship curve between the voltage and SOC is formed based on the voltage and SOC of the cell at each moment.

[0105] In an embodiment of the present application, when determining an expected voltage difference ΔVe(i) based on a current state of charge SOC(i) and a current balancing capacity ΔQ(i), a corresponding first voltage can be first mapped from an OCV curve based on the current state of charge SOC(i), a state of charge change ΔSOC(i) can be determined based on the current balancing capacity ΔQ(i), and then a corresponding second voltage can be mapped from the OCV curve based on the state of charge SOC(i)-ΔSOC(i), and the difference between the second voltage and the first voltage is the expected voltage difference ΔVe(i).

[0106] See also Fig. 9 In some embodiments, determining the actual balanced state of the battery cell based on the current voltage difference and the expected voltage difference (i.e., 0323) includes:

[0107] 03231: Determine whether the expected voltage difference is greater than the sum of a preset voltage constant of the current state of charge and a predetermined influencing factor;

[0108] 03232: When the expected voltage difference is greater than the sum of a preset voltage constant and a predetermined influencing factor, the actual balance state of the battery cell is determined according to the current voltage difference.

[0109] Specifically, the preset voltage constant ΔVc is a voltage constant preset according to the battery cell under different states of charge SOC(i). Through experimental design, the correspondence between different states of charge SOC(i) and the preset voltage constant ΔVc can be obtained in advance and stored in a table. The implementation method of the present application obtains the preset voltage constant ΔVc corresponding to the current state of charge SOC(i) by looking up the table. The error influence factor δ is related to the data sampling accuracy, data processing accuracy, and battery characteristics, and can be obtained by calibration testing in actual applications. The error influence factor δ in the implementation method of the present application is a positive number.

[0110] When the expected voltage difference ΔVe(i)>(ΔVc+δ), the actual equilibrium state judgment is triggered, otherwise the actual equilibrium state judgment is not performed. When the actual equilibrium state judgment is triggered, the actual equilibrium state of the battery cell is further determined based on the current voltage difference ΔVr(i). In the implementation mode of the present application, when the expected voltage difference reaches a certain level, the actual equilibrium state judgment is performed again, so as to more accurately determine the actual equilibrium state and prevent misjudgment. If the actual equilibrium state of the battery cell is determined directly based on the current voltage difference ΔVr(i), the current voltage difference ΔVr(i) may suddenly change or accidentally change due to interference and other factors, thereby obtaining an erroneous equilibrium state judgment result.

[0111] See also Fig.10 In some embodiments, when the expected voltage difference is greater than the sum of the preset voltage constant and the predetermined influencing factor, determining the actual equilibrium state of the battery cell (ie, 03232) according to the current voltage difference includes:

[0112] 032321: When the expected voltage difference is greater than the sum of the preset voltage constant and the predetermined influencing factor, determining whether the current voltage difference is greater than the preset voltage constant;

[0113] 032322: If the current voltage difference is greater than the preset voltage constant, it is determined that the cell balancing is normal;

[0114] 032323: If the current voltage difference is less than the preset voltage constant, it is determined that the cell balancing is abnormal.

[0115] Specifically, when the expected voltage difference ΔVe(i)>(ΔVc+δ), further, if the current voltage difference ΔVr(i)>ΔVc, it means that the expected balancing effect has been achieved, and it is determined that the balancing of the i-th battery cell is normal, and the balancing circuit of the i-th channel can be determined to be normal; if the current voltage difference ΔVr(i)<ΔVc, it means that the expected balancing effect has not been achieved, and it is determined that the balancing of the i-th battery cell is abnormal, and the balancing circuit of the i-th channel can be determined to be abnormal. Among them, when the current voltage difference ΔVr(i)=ΔVc, it can be preset to determine that the balancing of the i-th battery cell is normal, or preset to determine that the balancing of the i-th battery cell is abnormal, and there is no limitation here. The embodiment of the present application adopts the above-mentioned balancing state detection method to individually determine the actual balancing state of each battery cell, and the judgment result is relatively accurate.

[0116] See also Fig.11 The balanced state detection device 100 of the embodiment of the present application includes a judgment module 10, an acquisition module 20 and a determination module 30. The judgment module 10 is used to judge whether the battery pack meets the static balanced condition. The acquisition module 20 is used to obtain the static balanced time information and voltage information of each battery cell in the battery pack when the battery pack meets the static balanced condition. The determination module 30 is used to determine the actual balanced state of the battery cell based on the time information and the voltage information.

[0117] In some embodiments, the balanced state detection device 100 further includes a sending module 40. The acquisition module 20 is further used to acquire the cell parameters of the plurality of cells in the battery pack. The judgment module 10 is further used to perform consistency judgment on the plurality of cells according to the cell parameters to determine the balanced requirement of each cell. The sending module 40 is used to send a balanced instruction to the corresponding cell according to the balanced requirement. After the sending module 40 sends the balanced instruction to the corresponding cell according to the balanced requirement, the judgment module 10 determines whether the battery pack meets the static balanced condition.

[0118] In some embodiments, the judgment module 10 is specifically used to: if the battery pack stops charging and discharging and continues to reach a calibrated time threshold, and the maximum change value of the cell voltage of multiple cells in the battery pack is less than a predetermined voltage threshold within a predetermined time period, it is determined that the battery pack meets the static balancing condition; otherwise, it is determined that the battery pack does not meet the static balancing condition.

[0119] In some embodiments, the acquisition module 20 is specifically used to acquire the start time, start voltage, current time and current voltage of each cell in static balancing when the battery pack meets the static balancing condition. The determination module 30 is specifically used to: determine the current voltage difference and the current balancing capacity according to the start time, start voltage, current time and current voltage; and determine the actual balancing state of the cell based on the current voltage difference and the current balancing capacity.

[0120] In some implementations, the determination module 30 is specifically configured to: calculate the current voltage difference according to the starting voltage and the current voltage; and calculate the current balancing capacity according to the current voltage, the starting time, and the current time.

[0121] In some embodiments, the determination module 30 is specifically used to: obtain the current state of charge of each battery cell; determine the expected voltage difference according to the current state of charge and the current balancing capacity; and determine the actual balancing state of the battery cell based on the current voltage difference and the expected voltage difference.

[0122] In some embodiments, the determination module 30 is specifically used to: determine whether the expected voltage difference is greater than the sum of a preset voltage constant and a predetermined influencing factor of the current state of charge; when the expected voltage difference is greater than the sum of the preset voltage constant and the predetermined influencing factor, determine the actual balance state of the battery cell according to the current voltage difference.

[0123] In some embodiments, the determination module 30 is specifically used to: when the expected voltage difference is greater than the sum of a preset voltage constant and a predetermined influencing factor, determine whether the current voltage difference is greater than the preset voltage constant; if the current voltage difference is greater than the preset voltage constant, determine that the battery cell balancing is normal; if the current voltage difference is less than the preset voltage constant, determine that the battery cell balancing is abnormal.

[0124] It should be noted that the explanation of the equilibrium state detection method in the aforementioned embodiment is also applicable to the equilibrium state detection device 100 in the embodiment of the present application, and will not be further explained here.

[0125] See also Fig.12 The equilibrium state detection system 200 of the embodiment of the present application includes one or more processors 210 and a memory 220. The memory 220 stores a computer program. When the computer program is executed by the processor 210, the equilibrium state detection method of any of the above embodiments is implemented.

[0126] For example, when the computer program is executed by the processor 210, the following equilibrium state detection method is implemented:

[0127] 010: Determine whether the battery pack meets the static balancing conditions;

[0128] 020: When the battery pack meets the static balancing condition, obtain the static balancing time information and voltage information of each cell in the battery pack;

[0129] 030: Determine the actual balancing state of the battery cell based on the time information and the voltage information.

[0130] For another example, when the computer program is executed by the processor 210, the following equilibrium state detection method is implemented:

[0131] 040: Get the cell parameters of multiple cells in the battery pack;

[0132] 050: Perform consistency judgment on multiple cells based on cell parameters to determine the balancing requirements of each cell;

[0133] 060: Send balancing instructions to the corresponding battery cells according to balancing requirements;

[0134] After sending a balancing instruction to the corresponding battery cell according to the balancing requirement (ie 060), a step of determining whether the battery pack meets the static balancing condition (ie 010) is performed.

[0135] It should be noted that the explanation of the equilibrium state detection method in the aforementioned embodiment is also applicable to the equilibrium state detection system 200 in the embodiment of the present application, and will not be further explained here.

[0136] See also Fig.13 The computer-readable storage medium 300 of the embodiment of the present application stores a computer program 310 thereon, and when the program is executed by the processor 320, the equilibrium state detection method of any of the above-mentioned embodiments is implemented.

[0137] For example, when the program is executed by the processor 320, the following equilibrium state detection method is implemented:

[0138] 010: Determine whether the battery pack meets the static balancing conditions;

[0139] 020: When the battery pack meets the static balancing condition, obtain the static balancing time information and voltage information of each cell in the battery pack;

[0140] 030: Determine the actual balancing state of the battery cell based on the time information and the voltage information.

[0141] For another example, when the program is executed by the processor 320, the following equilibrium state detection method is implemented:

[0142] 040: Get the cell parameters of multiple cells in the battery pack;

[0143] 050: Perform consistency judgment on multiple cells based on cell parameters to determine the balancing requirements of each cell;

[0144] 060: Send balancing instructions to the corresponding battery cells according to balancing requirements;

[0145] After sending a balancing instruction to the corresponding battery cell according to the balancing requirement (ie 060), a step of determining whether the battery pack meets the static balancing condition (ie 010) is performed.

[0146] It should be noted that the explanation of the equilibrium state detection method in the aforementioned embodiment is also applicable to the computer-readable storage medium 300 in the embodiment of the present application, and will not be elaborated here.

[0147] In summary, the balanced state detection method, balanced state detection device 100, balanced state detection system 200 and computer-readable storage medium 300 of the embodiment of the present application obtain the time information and voltage information of each battery cell in the battery pack during static balancing when the battery pack meets the static balancing conditions, and determine the actual balanced state of the battery cell based on the time information and voltage information. In this way, the actual balanced state of the battery cell can be effectively detected, so as to verify the execution effect of the balanced instruction through the actual balanced state of the battery cell, and can cover the recognition of the actual balanced state of the battery cell under various working conditions, thereby improving the system safety of the battery pack.

[0148] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0149] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0150] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable storage medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, a computer-readable storage medium can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples (non-exhaustive list) of computer-readable storage media include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable storage medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0151] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0152] A person of ordinary skill in the art will appreciate that all or part of the steps carried by the method for implementing the above-mentioned embodiment can be completed by instructing the relevant hardware through a program, and the program can be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment. In addition, each functional unit in each embodiment of the present application can be integrated into a processing module, or each unit can exist physically alone, or two or more units can be integrated into one module. The above-mentioned integrated module can be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. The above-mentioned storage medium can be a read-only memory, a disk or an optical disk, etc.

[0153] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application. The scope of the present application is defined by the claims and their equivalents.

Claims

1. A method for detecting an equilibrium state, characterized in that: include: Determine whether the battery pack meets the static balancing conditions; When the battery pack meets the static balancing condition, acquiring static balancing time information and voltage information of each battery cell in the battery pack; An actual balancing state of the battery cell is determined based on the time information and the voltage information.

2. The method for detecting a balanced state according to claim 1, characterized in that: The equilibrium state detection method further comprises: Obtaining cell parameters of the plurality of cells in the battery pack; Performing consistency judgment on the plurality of battery cells according to the battery cell parameters to determine the balancing requirement of each battery cell; Sending a balancing instruction to the corresponding battery cell according to the balancing requirement; After sending the balancing instruction to the corresponding battery cell according to the balancing requirement, the step of determining whether the battery pack meets the static balancing condition is performed.

3. The method for detecting a balanced state according to claim 1, characterized in that: The determining whether the battery pack meets the static balancing condition includes: If the battery pack stops charging and discharging and continues to reach a calibrated time threshold, and the maximum change value of the cell voltage of the plurality of cells in the battery pack is less than a predetermined voltage threshold within a predetermined time period, it is determined that the battery pack meets the static balancing condition; Otherwise, it is determined that the battery pack does not meet the static balancing condition.

4. The method for detecting a balanced state according to claim 1, characterized in that: When the battery pack meets the static balancing condition, obtaining static balancing time information and voltage information of each battery cell in the battery pack includes: When the battery pack meets the static balancing condition, obtaining the starting time, starting voltage, current time and current voltage of each battery cell for static balancing; The determining the actual balanced state of the battery cell based on the time information and the voltage information includes: Determine a current voltage difference and a current balancing capacity according to the start time, the start voltage, the current time and the current voltage; An actual balancing state of the battery cell is determined based on the current voltage difference and the current balancing capacity.

5. The method for detecting a balanced state according to claim 4, characterized in that: The determining of the current voltage difference and the current balancing capacity according to the start time, the start voltage, the current time and the current voltage comprises: Calculating the current voltage difference according to the starting voltage and the current voltage; The current balancing capacity is calculated according to the current voltage, the start time and the current time.

6. The method for detecting a balanced state according to claim 4, characterized in that: The determining the actual balancing state of the battery cell based on the current voltage difference and the current balancing capacity includes: Obtaining the current state of charge of each of the battery cells; determining an expected voltage difference according to the current state of charge and the current equalization capacity; An actual balanced state of the battery cell is determined based on the current voltage difference and the expected voltage difference.

7. The method for detecting a balanced state according to claim 6, characterized in that: The determining the actual balanced state of the battery cell based on the current voltage difference and the expected voltage difference includes: Determining whether the expected voltage difference is greater than the sum of a preset voltage constant of the current state of charge and a predetermined influencing factor; When the expected voltage difference is greater than the sum of the preset voltage constant and the predetermined influencing factor, the actual balanced state of the battery cell is determined according to the current voltage difference.

8. The method for detecting a balanced state according to claim 7, characterized in that: When the expected voltage difference is greater than the sum of the preset voltage constant and the predetermined influencing factor, determining the actual balanced state of the battery cell according to the current voltage difference includes: When the expected voltage difference is greater than the sum of the preset voltage constant and the predetermined influencing factor, determining whether the current voltage difference is greater than the preset voltage constant; If the current voltage difference is greater than the preset voltage constant, it is determined that the cell balancing is normal; If the current voltage difference is less than the preset voltage constant, it is determined that the cell balancing is abnormal.

9. A balanced state detection device, characterized in that: include: A judgment module, used to judge whether the battery pack meets the static balancing condition; An acquisition module, used for acquiring time information and voltage information of static equalization of each battery cell in the battery pack when the battery pack meets the static equalization condition; A determination module is used to determine an actual balancing state of the battery cell based on the time information and the voltage information.

10. A balance state detection system, characterized in that: The equilibrium state detection system includes one or more processors and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, the equilibrium state detection method according to any one of claims 1 to 8 is implemented.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the equilibrium state detection method described in any one of claims 1 to 8 is implemented.

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