Battery health state estimation method and device, computer equipment and storage medium

Abstract

The invention relates to the technical field of electronics, and discloses a battery health state estimation method and device, computer equipment and a storage medium, and the method comprises the steps: determining an inflection point moment corresponding to a corresponding single cell by using each charging curve; according to the charging data of each single cell, determining the capacity difference of the corresponding single cell from the inflection point moment to the moment corresponding to the charging cut-off voltage; determining the actual capacity of the corresponding single cell according to the capacity difference of each single battery; the health states corresponding to different single cells can be calculated based on the actual capacity of each single cell, and the health state of the to-be-estimated battery can be accurately evaluated based on the health states corresponding to different single cells. The health state of the to-be-estimated battery is estimated through the actual capacities of the different single cells, and the inconsistency of the charge and discharge characteristics of the different single cells is considered, so that the estimated health state of the battery is more accurate.

Description

Technical Field

[0001] The present invention relates to the field of electronic technology, and in particular to a battery health state estimation method, device, computer equipment and storage medium. Background Art

[0002] The state of health (SOH) of lithium-ion batteries has always been a key indicator for evaluating battery performance and life. Accurately estimating the battery SOH can effectively prevent the impact of thermal runaway and aging on the battery system. Lithium iron phosphate (LFP) batteries are currently widely used due to their safety and stability. However, due to their charging and discharging characteristics, there are major challenges in estimating the SOH of LFP batteries. Single cells are combined in a battery pack in the form of series and parallel connection. The charging and discharging characteristics of each single cell in the battery pack are inconsistent. There are many methods for estimating SOH. They only calculate the actual capacity of the entire battery and estimate the SOH of the entire battery pack based on the actual capacity. The different charging and discharging characteristics of different single cells in the LFP battery are not considered, which makes the calculation result of the actual capacity of the entire battery inaccurate, and thus the health status of the battery cannot be accurately estimated. Summary of the invention

[0003] In view of this, the present invention provides a battery health status estimation method, device, computer equipment and storage medium to solve the problem that the actual capacity of the entire battery is calculated and the SOH of the entire battery pack is estimated based on the actual capacity, without considering the different charging and discharging characteristics of different single cells in the LFP battery, thereby making the calculation result of the actual capacity of the entire battery not accurate enough.

[0004] In a first aspect, the present invention provides a method for estimating a battery health state, the method comprising: obtaining a charging curve, charging data and a target time when the battery to be estimated reaches a fully charged state for each single cell when the battery to be estimated is charged under a first preset charging condition; determining the inflection point time corresponding to the corresponding single cell using each charging curve; determining the capacity difference of the corresponding single cell from the inflection point time to the time corresponding to the charging cut-off voltage according to the charging data, inflection point time, charging curve and target time of each single cell; determining the actual capacity of the corresponding single cell according to the capacity difference of each battery cell; and determining the health state of the battery to be estimated based on the actual capacities corresponding to different single cells in the battery to be estimated.

[0005] The battery health state estimation method provided by the present invention determines the inflection point moment corresponding to the corresponding single cell by using each charging curve; determines the capacity difference of the corresponding single cell from the inflection point moment to the charging cut-off moment according to the charging data of each single cell; determines the actual capacity of the corresponding single cell according to the capacity difference of each battery cell; and determines the health state of the battery to be estimated based on the actual capacities corresponding to different single cells in the battery to be estimated. The method provided by the present invention determines the capacity difference of each single cell from the inflection point moment to the moment corresponding to the charging cut-off voltage based on the charging data, inflection point moment, charging curve and target moment of each single cell, determines the actual capacity of the corresponding single cell according to the capacity difference of each single cell, calculates the health state corresponding to different single cells based on the actual capacity of each single cell, and accurately evaluates the health state of the battery to be estimated based on the health state corresponding to different single cells. The health state of the battery to be estimated is estimated by the actual capacity of different single cells, taking into account the inconsistency of the charging and discharging characteristics of different single cells, so that the estimated battery health state is more accurate.

[0006] In an optional embodiment, the step of determining the capacity difference of the corresponding single cell from the inflection point moment to the target moment according to the charging data of each single cell includes: determining a first inflection point moment in the charging curve of the first single cell and a second inflection point moment in the charging curve of each second single cell, the first single cell being the single cell that first reaches the charging cut-off voltage among multiple single cells of the battery to be estimated, and the second single cell being any single cell except the first single cell among the multiple single cells of the battery to be estimated; determining a first capacity difference corresponding to the second single cell by using the charging data of each second single cell, the first capacity difference of each second single cell being used to characterize the capacity difference from the second inflection point moment of the corresponding second single cell to the target moment; determining a second capacity difference corresponding to the second single cell based on the charging curve of each second single cell, the charging data, the first capacity difference and the charging curve of the first single cell.

[0007] In an optional embodiment, the step of determining the second capacity difference of the corresponding second single cell based on the charging curve of each second single cell, the first capacity difference and the charging curve of the first single cell includes: determining the first voltage of the corresponding second single cell at the target time based on the charging curve of each second single cell; determining the first time corresponding to the first voltage of each second single cell in the target charging curve, the target charging curve is the charging curve corresponding to the first single cell; calculating the cumulative charging capacity of the corresponding second single cell based on the charging data of the first single cell from the first time corresponding to each second single cell to the target time; determining the second capacity difference of the corresponding second single cell based on the cumulative charging capacity of each second single cell, the time difference and the first capacity difference, the time difference being used to characterize the time difference between the second inflection point moment of the corresponding second single cell and the first inflection point moment of the first single cell.

[0008] In an optional implementation, determining the second capacity difference corresponding to the second single battery cell based on the accumulated charging capacity of each second single battery cell, the time difference, and the first capacity difference includes:

[0009] Substitute the accumulated charging capacity, time difference and first capacity difference of each second single battery cell into the pre-constructed target relationship to calculate the second capacity difference corresponding to the second single battery cell. The target relationship is:

[0010] ΔC i =ΔC ′ +a×ΔT fi ×ΔC ui

[0011] Where, ΔC i Indicates the second capacity difference of the second single cell, ΔC ′ represents the first capacity difference of the second single cell, a represents the inconsistency factor, ΔT fi Indicates the time difference, ΔC ui Indicates the cumulative charge capacity of the second single cell.

[0012] In an optional embodiment, the actual capacity corresponding to each single battery cell is determined according to each capacity difference, including: obtaining a target linear equation, the target linear equation is used to characterize the correlation between the actual capacity and the capacity difference of the battery to be estimated; substituting the capacity difference of each battery cell into the target linear equation in turn for calculation, and obtaining the actual capacity corresponding to different single battery cells in the battery to be estimated.

[0013] In an optional embodiment, the target linear equation is constructed by the following steps: obtaining the capacity difference and the actual capacity of the reference battery corresponding to different numbers of cycles; and constructing the target linear equation based on the capacity difference and the actual capacity of the reference battery corresponding to different numbers of cycles.

[0014] In a second aspect, the present invention provides a battery health status estimation device, which includes: an acquisition module, used to obtain the charging curve, charging data and target time when the battery to be estimated reaches a fully charged state of each single cell when the battery to be estimated is charged under a first preset charging condition; a first determination module, used to determine the inflection point time corresponding to the corresponding single cell using each charging curve; a second determination module, used to determine the capacity difference of the corresponding single cell from the inflection point time to the time corresponding to the charging cut-off voltage according to the charging data, inflection point time, charging curve and target time of each single cell; a third determination module, used to determine the actual capacity corresponding to each single cell according to each capacity difference; and a fourth determination module, used to determine the health status of the battery to be estimated based on the actual capacities corresponding to different single cells in the battery to be estimated.

[0015] In a third aspect, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor are communicatively connected to each other, computer instructions are stored in the memory, and the processor executes the battery health status estimation method of the first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0016] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the battery health status estimation method of the first aspect or any corresponding embodiment thereof.

[0017] In a fifth aspect, the present invention provides a computer program product, comprising computer instructions, wherein the computer instructions are used to enable a computer to execute the battery health status estimation method of the above-mentioned first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 is a flowchart of a method for estimating a battery health state according to an embodiment of the present invention;

[0020] Figure 2 is a flow chart of another battery health status estimation method according to an embodiment of the present invention;

[0021] Figure 3is a schematic diagram of charging curves of a first battery cell and a second battery cell according to an embodiment of the present invention;

[0022] Figure 4 is a structural block diagram of a battery health status estimation device according to an embodiment of the present invention;

[0023] Figure 5 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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 described embodiments are 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0025] In the related art, single cells are combined in the battery pack in the form of series and parallel connection. Due to the inconsistency of the charge and discharge characteristics of each single cell in the battery pack, there are many methods for estimating SOH. The methods only calculate the actual capacity of the battery as a whole and estimate the SOH of the battery pack as a whole based on the actual capacity. The different charge and discharge characteristics of different single cells in the LFP battery are not considered, which makes the calculation result of the actual capacity of the battery as a whole not accurate enough, and thus the health status of the battery cannot be accurately estimated.

[0026] In view of this, a battery health status estimation method provided in an embodiment of the present application can be applied to a server to realize the estimation of the battery health status. The method provided by the present invention determines the capacity difference of each single cell from the inflection point to the charging cut-off time based on the charging data of each single cell, and determines the actual capacity of the corresponding single cell according to the capacity difference of each single cell. The health status corresponding to different single cells can be calculated based on the actual capacity of each single cell, and the health status of the battery to be estimated can be accurately evaluated based on the health status corresponding to different single cells. The health status of the battery to be estimated is estimated by the actual capacity of different single cells, taking into account the inconsistency of the charging and discharging characteristics of different single cells, so that the estimated battery health status is more accurate.

[0027] According to an embodiment of the present invention, an embodiment of a battery health status estimation method 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.

[0028] In this embodiment, a battery health status estimation method is provided, which can be used for the above-mentioned server. The battery can be in the form of a battery pack, and the battery pack has multiple single cells. Figure 1 is a flow chart of a battery health status estimation method according to an embodiment of the present invention. Figure 1 As shown, the process includes the following steps:

[0029] Step S101 , obtaining a charging curve and charging data of each single cell of a battery to be estimated when the battery to be estimated is charged under a first preset charging condition, and a target time when the battery to be estimated reaches a fully charged state.

[0030] Exemplarily, the charging curve is used to characterize the change information of the charging voltage of the battery over time. The first preset charging condition can be to control the battery to be estimated to be charged under the conditions of the first temperature and the first rate. The specific content of the first temperature and the first rate is not limited in the embodiment of the application, and those skilled in the art can determine it according to needs. The charging data may include but is not limited to the current and voltage data of each single cell during the charging process.

[0031] Step S102: using each charging curve to determine the inflection point time corresponding to the corresponding single battery cell.

[0032] Exemplarily, the charging curve is used to reflect the change pattern of the battery voltage with the charging time during the charging process. The battery voltage rises rapidly in the initial charging stage, and the greater the charging rate, the faster the voltage rises; then, the battery voltage enters a slowly changing stage, and the slope of the charging curve remains basically unchanged. This period of time is called the first plateau period of the battery. The smaller the charging rate, the longer the plateau period lasts; then, the slope of the charging curve gradually increases, and after reaching a certain value, the slope of the charging curve gradually decreases, and then the slope of the charging curve remains basically unchanged, and the battery enters the second plateau period; after the second plateau period ends, the charging voltage of the charging curve gradually increases with time until it reaches the cut-off voltage.

[0033] The inflection point moment is within the target interval in the charging curve, and the target interval is between the first plateau and the second plateau. The embodiment of the present application does not limit the specific content of the target interval, as long as it is reasonable. More specifically, in the process of the battery's charging curve from the first plateau to the second plateau, the slope of the charging curve changes from increasing to decreasing. The turning point is the inflection point position, and the moment corresponding to the inflection point position is the inflection point moment. The first plateau period may include but is not limited to a charging state in which the SOC is between 35% and 55% when the battery is charged, and the second plateau period may include but is not limited to a charging state in which the SOC is between 60% and 75% when the battery is charged, wherein SOC equals 1 to indicate that the battery is fully charged. It should be noted that SOC (State of charge), that is, the battery state of charge, is used to reflect the remaining capacity of the battery, and its numerical value is defined as the ratio of the remaining capacity to the rated capacity of the battery, and is usually expressed as a percentage.

[0034] Step S103 , determining the capacity difference of the corresponding single cell from the inflection point to the time corresponding to the charging cut-off voltage according to the charging data, the inflection point, the charging curve and the target time of each single cell.

[0035] Exemplarily, the capacity difference of each cell from the inflection point to the time corresponding to the charging cut-off voltage is calculated based on the charging data, inflection point time, charging curve and target time of each cell. In the embodiment of the present application, when any cell in the battery pack reaches the cut-off voltage, the battery pack stops charging, and the cell that first reaches the cut-off voltage in the battery pack is the first cell, and the time corresponding to the first charging cut-off voltage of the first cell is the target time. Any cell other than the first cell among the multiple cells of the battery to be estimated is the second cell, and the first charging cut-off voltage can be used as the charging cut-off voltage of the second cell. The capacity difference of the first single cell from the inflection point moment to the moment corresponding to the charge cut-off voltage is the real capacity difference of the first single cell from the inflection point moment to the target moment; since the second single cell has not reached the charge cut-off voltage at the battery charge cut-off moment, the moment corresponding to the charge cut-off voltage of the second single cell is the predicted moment, and the capacity difference of the second single cell from the inflection point moment to the moment corresponding to the charge cut-off voltage is: the real capacity difference of the second single cell from the inflection point moment to the target moment + the predicted capacity difference from the target moment to the moment of the charge cut-off voltage of the second single cell.

[0036] Step S104, determining the actual capacity of the corresponding single battery cell according to the capacity difference of each battery cell.

[0037] Illustratively, in the embodiments of the present application, the charging curve of the battery will show a certain regular change with the increase of the number of cycles, and the capacity difference is determined based on the charging curve, so the capacity difference will show a certain regular change with the increase of the number of cycles; the increase in the number of cycles will cause the actual capacity of the battery to decrease, and based on the correlation between the capacity difference and the actual capacity of the battery, a target linear equation can be constructed, and the actual capacity of the single cell can be accurately calculated based on the target linear equation.

[0038] The calculation process of the capacity difference is as follows: obtaining a target linear equation, which is used to characterize the correlation between the actual capacity of the battery to be estimated and the capacity difference; substituting the capacity difference of each battery cell into the target linear equation in turn for calculation, and obtaining the actual capacities corresponding to different single cells in the battery to be estimated.

[0039] Specifically, the target linear equation is constructed through the following steps:

[0040] Step a1, obtaining the capacity difference and the actual capacity of the reference battery corresponding to different cycle times. More specifically, step a1 includes:

[0041] Step a11, obtaining the charging curves corresponding to different numbers of cycles of the reference battery under the second preset charging condition. Exemplarily, in the embodiment of the present application, for the battery to be estimated, the rated capacity of the corresponding battery cell is determined, a battery cell of the same specification is used as a reference battery, a first temperature and a first rate are set, a cycle decay operation is performed on the reference battery, the reference battery is decayed to a reference capacity, and the charging data of the reference battery in each cycle decay operation is obtained. The first rate range is [0.05C, 0.25C], and 1C represents the current intensity when the battery is fully discharged for one hour. Based on the charging data of the reference battery in each cycle, the charging curves corresponding to the reference battery at different numbers of cycles are determined.

[0042] Step a12, determining the inflection point time and charging cut-off time corresponding to each charging curve.

[0043] Step a13, based on the voltage and current data of the reference battery from the inflection point of each charging curve to the charging cut-off time, the capacity difference of the reference battery at the corresponding number of cycles is calculated. Exemplarily, the capacity difference corresponding to different number of cycles is calculated by the battery voltage and current data from the inflection point of each charging curve to the charging cut-off time.

[0044] Step a14, based on the preset battery capacity calculation method, calculate the actual capacity of the reference battery at different cycle times. For example, in the embodiment of the present application, the preset battery capacity calculation method is not limited, and those skilled in the art can determine according to needs, and calculate the actual capacity of the reference battery at different cycle times by the preset battery capacity calculation method.

[0045] Step a2, constructing a target linear equation based on the capacity difference and the actual capacity of the reference battery at different cycle times. For example, in the embodiment of the present application, based on the capacity difference and the actual capacity of the reference battery at different cycle times, the correlation between the capacity difference and the actual capacity of the battery is fitted to obtain the target linear equation. The target linear equation can be shown as follows:

[0046] C r =kΔC+v

[0047] Among them, k and b represent the fitting coefficients, C r represents the actual capacity, and ΔC represents the capacity difference.

[0048] Step S105 , determining the health status of the battery to be estimated based on actual capacities corresponding to different single cells in the battery to be estimated.

[0049] Exemplarily, the ratio of the actual capacity of the battery to the initial capacity can be used to characterize the health status of the battery. In the embodiment of the present application, the health status of each single cell can be calculated based on the actual capacity corresponding to each single cell, and the health status of the entire battery can be estimated based on the health status of each single cell. It is also possible to perform power balancing control on different cells based on the actual capacity corresponding to each single cell in the battery to be estimated. In the embodiment of the present application, conventional passive balancing or active balancing schemes can be used to perform power balancing control on different cells.

[0050] The battery health status estimation method provided in this embodiment determines the capacity difference of each single cell from the inflection point to the charging cut-off time based on the charging data of each single cell, and determines the actual capacity of the corresponding single cell based on the capacity difference of each single cell. The health status corresponding to each single cell can be calculated based on the actual capacity of each single cell, and the health status of the battery to be estimated can be accurately evaluated based on the health status corresponding to each single cell. The health status of the battery to be estimated is estimated by the actual capacity of different single cells, taking into account the inconsistency of the charge and discharge characteristics of different single cells, so that the estimated battery health status is more accurate.

[0051] In this embodiment, a battery health status estimation method is provided, which can be used for the above-mentioned server. The battery can be in the form of a battery pack, and the battery pack has multiple single cells. Figure 2 is a flow chart of a battery health status estimation method according to an embodiment of the present invention. Figure 2 As shown, the process includes the following steps:

[0052] Step S201, obtaining the charging curve and charging data of each single cell of the battery to be estimated when it is charged under the first preset charging condition, and the target time when the battery to be estimated reaches a fully charged state. Figure 1 Step S101 of the illustrated embodiment will not be described in detail here.

[0053] Step S202, using each charging curve to determine the inflection point time corresponding to the corresponding single cell. Figure 1 Step S101 of the illustrated embodiment will not be described in detail here.

[0054] Step S203 , determining the capacity difference of the corresponding single cell from the inflection point to the time corresponding to the charging cut-off voltage according to the charging data, the inflection point, the charging curve and the target time of each single cell.

[0055] Specifically, the above step S203 includes:

[0056] Step S2031, determine the first inflection point moment in the charging curve of the first single cell and the second inflection point moment in the charging curve of each second single cell. Exemplarily, the first single cell is the single cell that first reaches the charging cut-off voltage among the multiple single cells of the battery to be estimated, the first inflection point moment is the inflection point moment of the charging curve corresponding to the first single cell, and the second single cell is any single cell except the first single cell among the multiple single cells of the battery to be estimated. In the embodiment of the present application, when the battery to be estimated is fully charged, the corresponding moment is the target moment, at which time the voltage of the first single cell reaches the charging cut-off voltage, and the other single cells have not reached the charging cut-off voltage.

[0057] Step S2032: Determine the first capacity difference corresponding to the second single battery cell by using the charging data of each second single battery cell.

[0058] Exemplarily, the first capacity difference of each second single cell is used to characterize the charging capacity difference from the second inflection point moment of the corresponding second single cell to the target moment, which can be determined by the voltage data and current data of the second single cell. In the embodiment of the present application, the second inflection point moment corresponding to the inflection point position in the charging curve corresponding to the second single cell is determined, and then the first capacity difference corresponding to the second single cell is calculated based on the current and voltage change data of the second single cell from the second inflection point moment to the target moment.

[0059] Step S2033: determining a second capacity difference corresponding to the second single battery cell based on the charging curve of each second single battery cell, the charging data, the first capacity difference, and the charging curve of the first single battery cell.

[0060] In some optional implementations, the above step S2033 includes:

[0061] Step b1, determining the first voltage of the corresponding second single cell at the target time based on the charging curve of each second single cell. Exemplarily, the second single cell is any single cell except the first single cell among the multiple single cells of the battery to be estimated. In the embodiment of the present application, for the second single cell i, based on its corresponding charging curve, the voltage Ui of the second single cell at the target time can be determined.

[0062] Step b2, determining the first moment corresponding to the first voltage of each second battery cell in the target charging curve, where the target charging curve is the charging curve corresponding to the first battery cell. For example, in the embodiment of the present application, for the second battery cell i, the voltage U i The first moment T corresponding to the target charging curve i .

[0063] Step b3, based on the charging data of the first battery cell from the first moment to the target moment corresponding to each second battery cell, calculate the cumulative charging capacity of the corresponding second battery cell. i The voltage and current data up to the target time T are used to calculate the cumulative charging capacity ΔC of the corresponding second single cell. ui .

[0064] Step b4, determining the second capacity difference corresponding to the second single cell based on the accumulated charging capacity of each second single cell, the time difference and the first capacity difference, wherein the time difference is used to characterize the time difference between the second inflection point moment of the corresponding second single cell and the first inflection point moment of the first single cell.

[0065] In some optional implementations, the above step b4 includes:

[0066] Substitute the accumulated charging capacity, time difference and first capacity difference of each second single battery cell into the pre-constructed target relationship to calculate the second capacity difference corresponding to the second single battery cell. The target relationship is:

[0067] ΔC i =ΔC ′ +a×ΔT fi ×ΔC ui

[0068] Where, ΔC iIndicates the second capacity difference of the second single cell, ΔC ′ represents the first capacity difference of the second single cell, a represents the inconsistency factor, ΔT fi Indicates the time difference, ΔC ui Indicates the cumulative charging capacity of the second single cell. In the embodiment of the present application, the unit of a is: 1 / time unit, which can be calibrated, and the range of a is (0,1). In the embodiment of the present application, the schematic diagram of the charging curve of the first single cell m and the second single cell i can be as follows Figure 3 As shown, where ΔT i Indicates the first time T corresponding to the second single cell i i The time interval between the target time T and the target time T. In the embodiment of the present application, based on the inconsistency factor a and the time difference ΔT fi Cumulative charge capacity ΔC ui Adjustment can be made to make the calculated second capacity difference ΔC i Under the same other conditions, the inconsistency of the single cells in the battery pack is mainly determined by the attenuation of each single cell. The first single cell that is charged to the cut-off voltage has the most serious attenuation, and its charging curve is also steeper. The attenuation of the second single cell is relatively small, and its charging curve is relatively gentle. This inconsistency can be expressed by the time difference ΔT of each second single cell. fi To measure the time difference ΔT fi The larger it is, the lower the attenuation degree is, and the larger the second capacity value calculated at the end is.

[0069] Step S204, determining the actual capacity of the corresponding battery cell according to the capacity difference of each battery cell. Figure 1 Step S104 of the illustrated embodiment will not be described in detail here.

[0070] Step S205, determining the health status of the battery to be estimated based on the actual capacities of the different cells in the battery to be estimated. Figure 1 Step S105 of the illustrated embodiment will not be described in detail here.

[0071] In this embodiment, a battery health status estimation device is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and will not be repeated here. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0072] This embodiment provides a battery health status estimation device, such as Figure 4 As shown, including:

[0073] An acquisition module 401 is used to acquire a charging curve and charging data of each single cell of the battery to be estimated when the battery to be estimated is charged under a first preset charging condition, and a target time when the battery to be estimated reaches a fully charged state;

[0074] A first determination module 402 is used to determine the inflection point time corresponding to the corresponding single battery cell by using each charging curve;

[0075] The second determination module 403 is used to determine the capacity difference of the corresponding single cell from the inflection point moment to the moment corresponding to the charging cut-off voltage according to the charging data, the inflection point moment, the charging curve and the target moment of each single cell;

[0076] The third determination module 404 is used to determine the actual capacity corresponding to each single cell according to each capacity difference;

[0077] The fourth determining module 405 is used to determine the health status of the battery to be estimated based on the actual capacities corresponding to different single cells in the battery to be estimated.

[0078] In some optional implementations, the target linear equation is constructed by the following steps:

[0079] Obtain the capacity difference and actual capacity of the reference battery at different cycle times;

[0080] The target linear equation is constructed based on the capacity difference of the reference battery at different cycle times and the actual capacity of the battery.

[0081] In some optional implementations, the second determining module 403 includes:

[0082] A first determination submodule is used to determine a first inflection point moment in a charging curve of a first single cell and a second inflection point moment in a charging curve of each second single cell, wherein the first single cell is a single cell that first reaches a charging cut-off voltage among multiple single cells of the battery to be estimated, and the second single cell is any single cell among multiple single cells of the battery to be estimated except the first single cell;

[0083] A second determination submodule, configured to determine a first capacity difference of the corresponding second single battery cell from the second inflection point to the target time by using the charging data of each second single battery cell;

[0084] The third determination submodule is used to determine the second capacity difference corresponding to the second single battery cell based on the charging curve of each second single battery cell, the charging data, the first capacity difference and the charging curve of the first single battery cell.

[0085] In some optional implementations, the third determining submodule includes:

[0086] A first determining unit, configured to determine a first voltage of a corresponding second single battery cell at a target time based on a charging curve of each second single battery cell;

[0087] A second determining unit, used to determine a first moment corresponding to the first voltage of each second battery cell in a target charging curve, where the target charging curve is a charging curve corresponding to the first battery cell;

[0088] A calculation unit, configured to calculate the accumulated charging capacity of the corresponding second single battery cell based on the charging data of the first single battery cell from the first moment to the target moment corresponding to each second single battery cell;

[0089] The third determining unit is used to determine the second capacity difference of the corresponding second single battery cell based on the cumulative charging capacity of each second single battery cell, the time difference and the first capacity difference, and the time difference is used to characterize the time difference between the second inflection point moment of the corresponding second single battery cell and the first inflection point moment of the first single battery cell.

[0090] In some optional implementations, the third determining unit includes:

[0091] Substitute the accumulated charging capacity, time difference and first capacity difference of each second single battery cell into the pre-constructed target relationship to calculate the second capacity difference corresponding to the second single battery cell. The target relationship is:

[0092] ΔC i =ΔC ′ +a×ΔT fi ×ΔC ui

[0093] Where, ΔC i Indicates the second capacity difference of the second single cell, ΔC ′ represents the first capacity difference of the second single cell, a represents the inconsistency factor, ΔT fi Indicates the time difference, ΔC ui Indicates the cumulative charge capacity of the second single cell.

[0094] In some optional implementations, the third determining module 404 includes:

[0095] An acquisition submodule, used to acquire a target linear equation, where the target linear equation is used to characterize the correlation between the actual capacity and the capacity difference of the battery to be estimated;

[0096] The calculation submodule is used to substitute the capacity difference of each battery cell into the target linear equation in turn for calculation, so as to obtain the actual capacity corresponding to different single cells in the battery to be estimated.

[0097] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0098] The battery health status estimation device in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0099] The embodiment of the present invention also provides a computer device having the above Figure 4 A battery health status estimation device is shown.

[0100] See also Figure 5 , Figure 5 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Figure 5 As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 5 A processor 10 is taken as an example.

[0101] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0102] The memory 20 stores instructions executable by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiment.

[0103] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0104] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0105] The computer device further comprises a communication interface 30 for the computer device to communicate with other devices or a communication network.

[0106] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0107] A part of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the existence of the computer program instruction in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc., and accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium accessible to the computer.

[0108] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for estimating a battery health state, characterized in that: The battery comprises a plurality of single cells, and the method comprises: Obtaining a charging curve and charging data of each single cell of the battery to be estimated when the battery to be estimated is charged under a first preset charging condition, and a target time when the battery to be estimated reaches a fully charged state; Determine the inflection point time corresponding to the single battery cell by using each of the charging curves; Determine the capacity difference of the corresponding single cell from the inflection point to the time corresponding to the charging cut-off voltage according to the charging data, the inflection point time, the charging curve and the target time of each single cell; Determining the actual capacity of the corresponding battery cell according to the capacity difference of each battery cell; The health state of the battery to be estimated is determined based on the actual capacities respectively corresponding to different single cells in the battery to be estimated.

2. The method according to claim 1, characterized in that The step of determining the capacity difference of the corresponding single cell from the inflection point to the charging cut-off time according to the charging data, the inflection point time, the charging curve and the target time of each single cell comprises: Determine a first inflection point in a charging curve of a first single cell and a second inflection point in a charging curve of each second single cell, wherein the first single cell is a single cell that first reaches a charging cut-off voltage among multiple single cells of the battery to be estimated, and the second single cell is any single cell among multiple single cells of the battery to be estimated except the first single cell; Determine a first capacity difference of the corresponding second single battery cell by using the charging data of each second single battery cell, wherein the first capacity difference of each second single battery cell is used to represent the capacity difference from the second inflection point moment of the corresponding second single battery cell to the target moment; Based on the charging curves of the second single battery cells, the charging data, the first capacity difference and the charging curves of the first single battery cells, a second capacity difference corresponding to the second single battery cells is determined.

3. The method according to claim 2, characterized in that The step of determining the second capacity difference corresponding to the second single battery cell based on the charging curve of each second single battery cell, the charging data, the first capacity difference and the charging curve of the first single battery cell comprises: Determining a first voltage of the corresponding second single battery cell at the target time based on a charging curve of each second single battery cell; Determine a first moment corresponding to the first voltage of each second battery cell in the target charging curve, where the target charging curve is a charging curve corresponding to the first battery cell; Based on the charging data of the first battery cell from the first time corresponding to each second battery cell to the target time, the accumulated charging capacity of the corresponding second battery cell is calculated; Based on the accumulated charging capacity of each second battery cell, the time difference and the first capacity difference, a second capacity difference corresponding to the second battery cell is determined, wherein the time difference is used to characterize the time difference between the second inflection point moment of the corresponding second battery cell and the first inflection point moment of the first battery cell.

4. The method according to claim 3, characterized in that The determining the second capacity difference corresponding to the second single battery cell based on the accumulated charging capacity of each second single battery cell, the time difference and the first capacity difference includes: Substituting the accumulated charging capacity of each second single battery cell, the time difference and the first capacity difference into a pre-constructed target relationship, the second capacity difference corresponding to the second single battery cell is calculated, and the target relationship is: ΔC i =ΔC ′ +a×ΔT fi ×ΔC ui Where, ΔC i Indicates the second capacity difference of the second single cell, ΔC ′ represents the first capacity difference of the second single cell, a represents the inconsistency factor, ΔT fi represents the time difference, the ΔC ui Indicates the cumulative charge capacity of the second single cell.

5. The method according to any one of claims 1 to 4, characterized in that: The determining of the actual capacities corresponding to the individual cells according to the capacity differences includes: Obtaining a target linear equation, where the target linear equation is used to characterize the correlation between the actual capacity and the capacity difference of the battery to be estimated; Substitute the capacity difference of each battery cell into the target linear equation in turn for calculation, and obtain the actual capacities corresponding to different battery cells in the battery to be estimated.

6. The method according to claim 5, characterized in that The target linear equation is constructed by the following steps: Obtain the capacity difference and actual capacity of the reference battery at different cycle times; The target linear equation is constructed based on the capacity difference corresponding to the reference battery at different cycle times and the actual capacity of the battery.

7. A battery health status estimation device, characterized in that: The device comprises: An acquisition module, used to acquire a charging curve and charging data of each single cell of the battery to be estimated when the battery to be estimated is charged under a first preset charging condition, and a target time when the battery to be estimated reaches a fully charged state; A first determination module, configured to determine the inflection point moment corresponding to the single battery cell by using each of the charging curves; A second determination module is used to determine the capacity difference of the corresponding single cell from the inflection point moment to the moment corresponding to the charging cut-off voltage according to the charging data, the inflection point moment, the charging curve and the target moment of each single cell; A third determination module is used to determine the actual capacity corresponding to each single cell according to each capacity difference; The fourth determination module is used to determine the health state of the battery to be estimated based on actual capacities corresponding to different single cells in the battery to be estimated.

8. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the battery health status estimation method according to any one of claims 1 to 6 by executing the computer instructions.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the battery health state estimation method according to any one of claims 1 to 6.

10. A computer program product, characterized in that The method comprises computer instructions, wherein the computer instructions are used to cause a computer to execute the battery health state estimation method according to any one of claims 1 to 6.

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