Battery state analysis methods, apparatus, equipment and storage media

Abstract

This invention discloses a battery state analysis method, apparatus, device, and storage medium. The battery state analysis method includes: acquiring the individual cell voltage data of a battery cell; if the individual cell voltage data is higher than a preset individual cell voltage threshold, performing differential calculation on the individual cell voltage data to obtain differential voltage data; searching for inflection points in the differential voltage data according to a preset relational value table to obtain characteristic inflection points; acquiring the integral capacity of the power supply battery based on the characteristic inflection points to obtain characteristic capacity; and performing numerical calculations based on the characteristic capacity and a preset standard capacity to obtain a battery health state value. This invention can acquire the battery health state of an automotive power battery without requiring the battery to be idle.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a battery state analysis method, apparatus, device, and storage medium. Background Technology

[0002] Currently, online SOH estimation methods applied to automotive power batteries, especially lithium iron phosphate batteries, require the battery to be left to stand after full charging, and also when the battery voltage is in the non-plateau region, in order to obtain an accurate OCV. Finally, the accurate SOC is obtained by looking up the OCV in a table. This method has stringent requirements for obtaining the SOC, which is difficult to implement on lithium iron phosphate batteries. Summary of the Invention

[0003] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a battery state analysis method that can obtain the battery health status of an automotive power battery without requiring the battery to be idle.

[0004] The present invention also proposes a battery state analysis device.

[0005] The present invention also proposes a battery state analysis device.

[0006] The present invention also proposes a computer-readable storage medium.

[0007] In a first aspect, one embodiment of the present invention provides a battery state analysis method, comprising: acquiring single-cell voltage data of a battery cell;

[0008] If the individual cell voltage data is higher than the preset individual cell voltage threshold, the individual cell voltage data is differentiated to obtain the differential voltage data;

[0009] The differential voltage data is searched for inflection points according to a preset relational value table to obtain characteristic inflection points; wherein, the relational value table is constructed based on the pairing data of the differential voltage data and time.

[0010] The integral charge of the power supply battery is obtained based on the characteristic inflection point to obtain the characteristic charge.

[0011] The battery health status value is obtained by numerical calculation based on the characteristic charge level and the preset standard capacity.

[0012] The battery state analysis method of this invention has at least the following beneficial effects: It acquires the change value of the discharge current of the power supply battery and the current temperature of the power supply battery to obtain the current change value and the current temperature value. The current change value is compared with a preset current change threshold, and the current temperature value is compared with a preset temperature threshold. If the current change value is within the preset current change threshold, the cell voltage of each battery cell is acquired to obtain cell voltage data. The cell voltage data is compared with a preset cell voltage threshold. If the cell voltage data is higher than the preset cell voltage threshold, the cell voltage data is differentially calculated to obtain differential voltage data. The inflection point of the differential voltage data is found according to a preset relational value table to obtain a characteristic inflection point. The integral charge of the power supply battery is acquired based on the characteristic inflection point to obtain a characteristic charge. Numerical calculations are performed based on the characteristic charge and a preset standard capacity to obtain the battery health state value. This method can acquire the battery health state of an automotive power battery without requiring the battery to be idle.

[0013] According to other embodiments of the battery state analysis method of the present invention, the step of performing differential calculation on the single-cell voltage data to obtain differential voltage data if the single-cell voltage data is higher than a preset single-cell voltage threshold includes:

[0014] If the individual cell voltage data is higher than a preset individual cell voltage threshold, differential calculation is performed on the individual cell voltage data within a preset period to obtain the differential voltage data.

[0015] According to other embodiments of the battery state analysis method of the present invention, the differential voltage data includes multiple differential voltage values, and the step of finding inflection points in the differential voltage data according to a preset relational value table to obtain characteristic inflection points includes:

[0016] The differential voltage value at the target time of the current period is obtained according to the relational value table, and the target voltage value is obtained.

[0017] If the target voltage value is less than a preset voltage threshold, obtain the previous voltage value and the subsequent voltage value; wherein, the previous voltage value is the differential voltage value at a preset time before the current time, and the subsequent voltage value is the differential voltage value at a preset time after the current time;

[0018] The characteristic inflection point is obtained by comparing the target voltage value, the previous voltage value, and the subsequent voltage value.

[0019] According to other embodiments of the battery state analysis method of the present invention, the preset voltage threshold includes a preset first threshold and a preset second threshold, the feature inflection point includes a first feature inflection point and a second feature inflection point, and the step of obtaining the feature inflection point by numerical comparison based on the target voltage value, the previous voltage value and the subsequent voltage value includes:

[0020] If the target voltage value is less than the preset first threshold, and both the previous voltage value and the subsequent voltage value are greater than the target voltage value, the point where the target voltage value is located is taken as the first feature inflection point;

[0021] If the target voltage value is less than the preset second threshold, and both the previous voltage value and the subsequent voltage value are greater than the target voltage value, the point where the target voltage value is located is taken as the second feature inflection point.

[0022] According to other embodiments of the battery state analysis method of the present invention, the characteristic charge includes a first characteristic charge and a second characteristic charge, and the step of obtaining the integral charge of the power supply battery based on the characteristic inflection point to obtain the characteristic charge includes:

[0023] Obtain the initial point of discharge or charge of the power supply battery;

[0024] The first characteristic charge is obtained by integrating the initial point and the first characteristic inflection point, and the second characteristic charge is obtained by integrating the initial point and the second characteristic inflection point.

[0025] According to other embodiments of the battery state analysis method of the present invention, the step of calculating the battery health state value based on the characteristic charge and a preset standard capacity includes:

[0026] The difference between the first characteristic charge and the second characteristic charge is obtained to obtain the capacity difference.

[0027] The battery health status value is obtained by numerical calculation based on the capacity difference and the preset standard capacity.

[0028] According to other embodiments of the battery state analysis method of the present invention, the step of obtaining the battery health state value by numerical calculation based on the capacity difference and the preset standard capacity includes:

[0029] Obtain the difference in remaining power between the first feature inflection point and the second feature inflection point to obtain the remaining power difference;

[0030] The actual capacity is obtained by dividing the capacity difference and the remaining power difference.

[0031] The battery health status is obtained by dividing the actual capacity by the preset standard capacity.

[0032] Secondly, one embodiment of the present invention provides a battery state analysis apparatus, comprising:

[0033] Voltage data acquisition module, used to acquire the individual voltage data of battery cells;

[0034] The differential voltage acquisition module, if the individual cell voltage data is higher than a preset individual cell voltage threshold, performs differential calculations on the individual cell voltage data to obtain differential voltage data; wherein, the differential voltage data includes multiple differential voltage values;

[0035] The inflection point search module is used to search for inflection points in the differential voltage data according to a preset relational value table to obtain characteristic inflection points; wherein, the relational value table is constructed based on the pairing data of the differential voltage data and time.

[0036] The feature power acquisition module is used to acquire the integral power of the power supply battery based on the feature inflection point, and obtain the feature power.

[0037] The battery status calculation module is used to perform numerical calculations based on the characteristic charge level and the preset standard capacity to obtain the battery health status value.

[0038] The battery state analysis device of this invention has at least the following beneficial effects: the initial condition acquisition module acquires the change value of the discharge current of the power supply battery and the current temperature of the power supply battery to obtain the current change value and the current temperature value; the voltage data acquisition module compares the current change value with a preset current change threshold and compares the current temperature value with a preset temperature threshold; if the current change value is within the preset current change threshold, the cell voltage of each battery cell is acquired to obtain cell voltage data; the differential voltage acquisition module compares the cell voltage data with a preset cell voltage threshold; if the cell voltage data is higher than the preset cell voltage threshold, the differential calculation is performed on the cell voltage data to obtain differential voltage data; the inflection point search module searches for the inflection point of the differential voltage data to obtain the characteristic inflection point; the characteristic charge acquisition module acquires the integral charge of the power supply battery according to the characteristic inflection point to obtain the characteristic charge; the characteristic charge acquisition module performs numerical calculations based on the characteristic charge and a preset standard capacity to obtain the battery health state value, which can acquire the battery health state of the automotive power battery without the battery being idle.

[0039] Thirdly, one embodiment of the present invention provides a battery state analysis device, comprising:

[0040] At least one processor, and,

[0041] A memory communicatively connected to the at least one processor; wherein,

[0042] The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the battery state analysis method as described in the first aspect.

[0043] Fourthly, one embodiment of the present invention provides a computer-readable storage medium storing computer-executable instructions for causing a computer to perform the battery state analysis method as described in the first aspect.

[0044] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the description and the accompanying drawings. Attached Figure Description

[0045] Figure 1 This is a schematic flowchart of a specific embodiment of the battery state analysis method in this invention;

[0046] Figure 2 yes Figure 1 A schematic flowchart of a specific embodiment of step S102;

[0047] Figure 3 yes Figure 1 A schematic diagram of a specific embodiment of step S103;

[0048] Figure 4 yes Figure 3 A schematic diagram of a specific embodiment of step S303;

[0049] Figure 5 yes Figure 1 A schematic flowchart of a specific embodiment of step S104;

[0050] Figure 6 yes Figure 1 A schematic diagram of a specific embodiment of step S105;

[0051] Figure 7 yes Figure 6 A schematic diagram of a specific embodiment of step S602;

[0052] Figure 8 This is a schematic flowchart of another specific embodiment of the battery state analysis method in this invention;

[0053] Figure 9 This is a module block diagram of a specific embodiment of the battery state analysis device in this invention.

[0054] Figure 10 This is a schematic diagram of a specific embodiment of the relational value table in this invention;

[0055] Figure 11 This is a schematic diagram of another specific embodiment of the relational value table in the present invention. Attached image description:

[0057] Voltage data acquisition module 901, differential voltage acquisition module 902, inflection point search module 903, characteristic power acquisition module 904, and battery status calculation module 905. Detailed Implementation

[0058] The following will describe the concept and technical effects of the present invention clearly and completely with reference to the embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0059] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0060] It should be noted that although the system diagram shows functional modules and the flowchart shows the logical order, in some cases, the steps shown or described may be executed in a different order than the module division in the system or the order in the flowchart.

[0061] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0062] In the description of the embodiments of the present invention, the term "several" means one or more, and the term "multiple" means two or more. The terms "greater than," "less than," and "exceeding" should be understood as excluding the stated number, while the terms "above," "below," and "within" should be understood as including the stated number. The terms "first" and "second" should be understood as distinguishing technical features, and not as indicating or implying relative importance, the number of indicated technical features, or the order of the indicated technical features.

[0063] First, let's analyze the technical terms used in this application:

[0064] SOC refers to the state of charge of a battery, which is mainly used to reflect the remaining capacity of the battery. It is numerically defined as the ratio of the remaining capacity to the battery capacity.

[0065] Battery Management System (BMS), also known as battery nanny or battery steward, is mainly used for intelligent management and maintenance of each battery cell, preventing overcharging and over-discharging, extending battery life, and monitoring battery status.

[0066] SOH refers to the battery's capacity, health, and performance status. Simply put, it is the ratio of the battery's performance parameters to its nominal parameters after a period of use. A newly manufactured battery is 100%, while a completely scrapped battery is 0%.

[0067] OCV, or Open Circuit Voltage, is the potential difference between the two terminals of a battery when it is not discharged and is in an open circuit.

[0068] Existing methods for online SOH estimation in automotive power batteries mainly include: First, using empirical models derived from cell test data, inputting information such as cycle count, historical throughput, or storage time for estimation. This method, being an open-loop approach, can only provide a rough estimate of the SOH value for the entire pack, resulting in low accuracy. Second, obtaining accurate OCV based on the battery's resting state after full charge and when the voltage is in a non-plateau region, then using OCV to look up the accurate SOC change dSOC, and combining this with the recorded charge and discharge quantities between the two points to obtain SOH using the dQ / dSOC method. This method has stringent requirements for obtaining SOC, which is difficult to meet in automotive power batteries.

[0069] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a battery state analysis method that can obtain the battery health status of an automotive power battery without requiring the battery to be idle.

[0070] Please refer to Figure 1 , Figure 1 A flowchart illustrating the battery state estimation method in an embodiment of the present invention is shown. In some embodiments, it specifically includes, but is not limited to, steps S101 to S105.

[0071] Step S101: Obtain the individual cell voltage data of the battery cell;

[0072] Step S102: If the individual voltage data is higher than the preset individual voltage threshold, perform differential calculation on the individual voltage data to obtain differential voltage data.

[0073] Step S103: Find the inflection point of the differential voltage data according to the preset relational value table to obtain the characteristic inflection point;

[0074] Step S104: Obtain the integral charge of the power supply battery based on the feature inflection point to obtain the feature charge.

[0075] Step S105: Perform numerical calculations based on the characteristic charge level and the preset standard capacity to obtain the battery health status value.

[0076] By executing steps S101 to S105, the individual cell voltage of each battery cell is acquired, resulting in individual cell voltage data including multiple cell voltages. The individual cell voltage data is compared with a preset individual cell voltage threshold. If the individual cell voltage data is higher than the preset threshold, the individual cell voltage data is differentiated to obtain differential voltage data. Inflection points in the differential voltage data are identified to obtain characteristic inflection points. Based on these characteristic inflection points, the integral capacity of the power supply battery is obtained to obtain characteristic capacity. Based on the characteristic capacity and a preset standard capacity, a numerical calculation is performed to obtain the battery health status value. This improves the accuracy of obtaining the battery health status of automotive power batteries without requiring the battery to be idle.

[0077] It should be noted that the current temperature value was obtained from the BMS measurement. The relational value table was constructed based on the paired data of differential voltage and time.

[0078] Before step S101 in some embodiments, the change value of the discharge current of the power supply battery and the current temperature of the power supply battery are obtained respectively to obtain the current change value and the current temperature value. The current change value is compared with a preset current change threshold, and the current temperature value is compared with a preset temperature threshold. If the current change value is within the preset current change threshold and the current temperature value is greater than the preset temperature threshold, the cell voltage of each battery cell is obtained to obtain cell voltage data including multiple cell voltages.

[0079] The system acquires the current discharge current of the power supply battery in real time, and filters out the maximum and minimum values ​​of the discharge current within a preset time range. The difference between the maximum and minimum values ​​is calculated to obtain the change in discharge current, i.e., the current change value. This application does not specifically limit the preset time range. The preset current change threshold is preferably +2A or -2A, and the preset temperature threshold is preferably 20℃. This application does not specifically limit the preset current change threshold or the preset temperature threshold.

[0080] Specifically, if the current change value is within the range of [-2A, +2A] and the battery discharge rate is less than 1C, then it is determined whether the current temperature value is greater than a preset temperature threshold. If the current change value is not within the range of [-2A, +2A], or the battery discharge rate is not less than 1C, then a new current change value is obtained for judgment, until the above conditions are met. If the current temperature value is greater than 20℃, then the individual cell voltage of each battery cell is obtained to obtain individual cell voltage data. If the current temperature value is less than 20℃, then a new current change value is obtained for judgment, until the above conditions are met. Among these, if the current change value is within the range of [-2A, +2A], the current discharge current can be considered a constant current, and the charging or discharging current can be considered a constant current. Furthermore, if the current temperature value is greater than 20℃, the accuracy of the obtained battery health status can be improved.

[0081] Please refer to Figure 2 , Figure 2 A schematic flowchart of the battery state estimation method in an embodiment of the present invention is shown. In some embodiments, if the cell voltage data is higher than a preset cell voltage threshold, step S102 includes, but is not limited to, step S201.

[0082] Step S201: If the individual cell voltage data is higher than the preset individual cell voltage threshold, perform differential calculation on the individual cell voltage data within the preset period to obtain differential voltage data.

[0083] In step S201 of some embodiments, the individual cell voltage values ​​in the individual cell voltage data are compared one by one with a preset individual cell voltage threshold. If the individual cell voltage values ​​are all higher than the preset individual cell voltage threshold, differential calculation is performed on each individual cell voltage value within a preset period to obtain differential voltage data including multiple differential voltage values, so that the differential value corresponding to the voltage of each battery cell can be obtained in real time.

[0084] The preset individual cell voltage threshold is preferably 3.27V in this application, but no specific limit is made to the preset individual cell voltage threshold in this application. If the voltage value of any individual cell is lower than the preset individual cell voltage threshold, differential calculation is performed on the individual cell voltage data within the preset period only after all individual cell voltage values ​​are higher than the preset individual cell voltage threshold.

[0085] Differential processing is performed on each individual voltage value within a preset period to obtain multiple differential voltage values. These multiple differential voltage values ​​are then combined into a data string to obtain differential voltage data. The present invention executes the steps within a preset period duration. Each period constitutes an execution cycle, and the preset period is one of these execution cycles. The preset period can be defined as the i-th execution cycle among multiple execution cycles.

[0086] Please refer to Figure 3 , Figure 3 A schematic flowchart of the battery state estimation method in an embodiment of the present invention is shown. In some embodiments, the differential voltage data includes multiple differential voltage values, and step S103 includes, but is not limited to, steps S301 to S303.

[0087] Step S301: Obtain the differential voltage value at the target time of the current cycle according to the relational value table, and obtain the target voltage value;

[0088] Step S302: If the target voltage value is less than the preset voltage threshold, obtain the previous voltage value and the subsequent voltage value;

[0089] Step S303: Compare the target voltage value, the previous voltage value, and the subsequent voltage value to obtain the characteristic inflection point.

[0090] By executing steps S301 to S303, the target voltage value is obtained by obtaining the differential voltage value at the target time according to the relational value table. The target voltage value is compared with the preset voltage threshold. If the target voltage value is less than the preset voltage threshold, the previous voltage value and the subsequent voltage value are obtained. The target voltage value is compared with the previous voltage value and the subsequent voltage value to obtain the characteristic inflection point. The desired characteristic inflection point can be obtained.

[0091] It should be noted that steps S301 to S303 are executed one by one for each battery cell. If any battery cell does not obtain a characteristic inflection point, the differential voltage data of the battery cell that obtains the characteristic inflection point is stored, and steps S301 to S303 are executed again until each battery cell obtains the first characteristic inflection point.

[0092] In step S301 of some embodiments, the target voltage value is the differential voltage value at the target time of the current cycle.

[0093] Specifically, differential voltage data is used as the vertical axis parameter of the line graph, and time is used as the horizontal axis parameter. A curve is then plotted based on the formula used for differential calculation, resulting in a table of relationship values. The constructed curve is specifically referenced... Figure 10 and Figure 11 .

[0094] In step S302 of some embodiments, the preceding voltage value is the differential voltage value at a preset time before the current time, and the following voltage value is the differential voltage value at a preset time after the current time. The target voltage value, the preceding voltage value, and the following voltage value are all differential voltage values ​​within the same execution cycle. The preset time is preferably 10 minutes in this application. The preset time needs to have a certain time interval with the current time to reduce the similarity between the differential voltage value at the preset time and the differential voltage value at the current time. This application does not specifically limit the preset time. For example, if the target voltage value is dV(i), then i is the preset time, the preceding voltage value is dV(i-10), and the following voltage value is dV(i+10).

[0095] Please refer to Figure 4 , Figure 4 A flowchart illustrating the battery state analysis method in an embodiment of the present invention is shown. In some embodiments, the preset voltage threshold includes a preset first threshold and a preset second threshold, the feature inflection point includes a first feature inflection point and a second feature inflection point, and step S303 includes, but is not limited to, steps S401 to S402.

[0096] Step S401: If the target voltage value is less than a preset first threshold, and both the previous voltage value and the subsequent voltage value are greater than the target voltage value, the point where the target voltage value is located is taken as the first feature inflection point.

[0097] In step S402, if the target voltage value is less than a preset second threshold, and both the previous voltage value and the subsequent voltage value are greater than the target voltage value, the point where the target voltage value is located is taken as the second characteristic inflection point.

[0098] It should be noted that Figure 10 is the curve near the first characteristic inflection point, Figure 11 is the curve near the second characteristic inflection point.

[0099] In step S401 of some embodiments, the target voltage value is compared with a preset first threshold, the target voltage value is compared with the previous voltage value, and the target voltage value is compared with the subsequent voltage value. If the target voltage value is less than the preset first threshold, the target voltage value is less than the previous voltage value, and the target voltage value is less than the subsequent voltage value, then the point where the target voltage value is located is taken as the first characteristic inflection point, and the required first characteristic inflection point can be obtained. Among them, the preset first threshold is preferably -5 mV in this application, and the preset first threshold is not specifically limited in this application

[0100] For example, if the target voltage value is dV(i), the previous voltage value is dV(i - 10), and the subsequent voltage value is dV(i + 10). If dV(i) > -5 mV, dV(i - 10) > dV(i), and dV(i) < dV(i + 10), then the point where the target voltage value is located is taken as the first characteristic inflection point.

[0101] It should be noted that if any battery cell does not obtain the first characteristic inflection point, steps S301 to S303 and step S401 are repeatedly executed until each battery cell obtains the first characteristic inflection point.

[0102] In step S402 of some embodiments, the target voltage value is compared with a preset second threshold, the target voltage value is compared with the previous voltage value, and the target voltage value is compared with the subsequent voltage value. If the target voltage value is less than the preset second threshold, the target voltage value is less than the previous voltage value, and the target voltage value is less than the subsequent voltage value, then the point where the target voltage value is located is taken as the second characteristic inflection point, and the required second characteristic inflection point can be obtained. Among them, the preset second threshold is preferably -20 mV in this application, and the preset second threshold is not specifically limited in this application

[0103] For example, if the target voltage value is dV(i), the previous voltage value is dV(i - 10), and the subsequent voltage value is dV(i + 10). If dV(i) > -20 mV, dV(i - 10) > dV(i), and dV(i) < dV(i + 10), then the point where the target voltage value is located is taken as the second characteristic inflection point.

[0104] It should be noted that if any single battery cell fails to obtain the second characteristic inflection point, steps S301 to S303 and S402 are repeated until each battery cell obtains the second characteristic inflection point.

[0105] Please refer to Figure 5 , Figure 5 A schematic flowchart of a battery state analysis method according to an embodiment of the present invention is shown. In some embodiments, the characteristic charge includes a first characteristic charge and a second characteristic charge, and step S104 includes, but is not limited to, steps S501 to S502.

[0106] Step S501: Obtain the initial point of discharging or charging the power supply battery;

[0107] Step S502: Perform integration calculation based on the initial point and the first feature inflection point to obtain the first feature charge, and perform integration calculation based on the initial point and the second feature inflection point to obtain the second feature charge.

[0108] By executing steps S501 to S502, the initial point of the power supply battery at the beginning of its discharge or charge is obtained. The initial point and the first characteristic inflection point are used as the interval for integration. The interval is substituted into the formula of the corresponding curve for integration to obtain the first characteristic charge. The initial point and the second characteristic inflection point are used as the interval for integration. The interval is substituted into the formula of the corresponding curve for integration to obtain the second characteristic charge.

[0109] It should be noted that steps S501 to S502 are performed on each individual battery cell to obtain the corresponding first characteristic charge and second characteristic charge.

[0110] Please refer to Figure 10 and Figure 11 The formula for calculating the curve of the first characteristic charge is: Figure 10 The formula for calculating the curve of the second characteristic charge is as follows: Figure 11 The curve in the middle.

[0111] In step S502 of some embodiments, the first characteristic charge is the capacity of the power supply battery at the time of the first characteristic inflection point, and the second characteristic charge is the capacity of the power supply battery at the time of the second characteristic inflection point.

[0112] Please refer to Figure 6 , Figure 6 A flowchart illustrating the battery state analysis method in an embodiment of the present invention is shown. In some embodiments, step S105 includes, but is not limited to, steps S601 to S602.

[0113] Step S601: Obtain the difference between the first characteristic charge and the second characteristic charge to obtain the capacity difference;

[0114] Step S602: Calculate the battery health status value based on the capacity difference and the preset standard capacity.

[0115] By executing steps S601 to S602, the first characteristic charge and the second characteristic charge are subtracted to calculate the difference between the first characteristic charge and the second characteristic charge, and the capacity difference is obtained. The capacity difference and the preset standard capacity are input into a preset formula for numerical calculation to obtain the battery health status value. This can improve the accuracy of obtaining the battery health status of the automotive power battery without the battery being idle.

[0116] It should be noted that steps S601 to S602 are performed on each individual battery cell to obtain the corresponding battery health status.

[0117] Please refer to Figure 7 , Figure 7 A schematic flowchart of the battery state analysis method in an embodiment of the present invention is shown. In some embodiments, step S602 includes, but is not limited to, steps S701 to S703.

[0118] Step S701: Obtain the difference in remaining power between the first feature inflection point and the second feature inflection point to obtain the remaining power difference.

[0119] Step S702: Perform a division operation between the capacity difference and the remaining power difference to obtain the actual capacity;

[0120] Step S703: Divide the actual capacity and the preset standard capacity to obtain the battery health status.

[0121] By executing steps S701 to S703, the difference in remaining charge between the first characteristic inflection point and the second characteristic inflection point is obtained, resulting in the remaining charge difference. The capacity difference and the remaining charge difference are divided to obtain the actual capacity. The actual capacity is then divided by a preset standard capacity to obtain the battery health status. This improves the accuracy of obtaining the battery health status of the automotive power battery without requiring the battery to be idle.

[0122] It should be noted that steps S701 to S703 are performed on each individual battery cell to obtain the corresponding battery health status.

[0123] Based on steps S701 to S703, the formula can be obtained: Battery health status = Capacity difference ÷ (Remaining capacity difference * Preset standard capacity). For example, the battery health status is SOH. i The remaining power difference is 47%, and the preset standard capacity is FullCapacity, resulting in the formula: SOH i =dQ i / (47%*FullCapacity). First characteristic inflection point. Second characteristic inflection point.

[0124] In step S701 of some embodiments, before executing steps S101 to S105, an offline experiment is performed on the power supply battery to obtain the remaining power at the first characteristic inflection point and the remaining power at the second characteristic inflection point, thus obtaining the first remaining power at the first characteristic inflection point and the second remaining power at the second characteristic inflection point. The difference between the first remaining power and the second remaining power is calculated to obtain the remaining power difference. For example, the calculation process of the remaining power difference includes: the remaining power corresponding to the first characteristic inflection point is approximately 62%, the remaining power corresponding to the second characteristic inflection point is approximately 15%, and the remaining power difference is 62% minus 15% to obtain 47%.

[0125] In step S703 of some embodiments, the preset standard capacity is the standard capacity of the power supply battery when it leaves the factory.

[0126] Please refer to Figure 8 , Figure 8 A flowchart illustrating the battery state analysis method in an embodiment of the present invention is shown. In some embodiments, it specifically includes:

[0127] First, determine if the discharge current of the power supply battery is constant. If it is, check if the current temperature of the power supply battery is greater than 20°C. If the current temperature is not greater than 20°C, obtain a new discharge current and re-evaluate. If the current temperature is greater than 20°C, wait for the individual cell voltage data of each battery cell to reach its characteristic inflection point. Then, perform differential calculations on the individual cell voltage data of each battery cell to obtain the corresponding differential voltage data, which includes multiple differential voltage values. Based on the differential voltage values ​​of the first and second characteristic inflection points, obtain the amount of electricity discharged at the first and second characteristic inflection points, i.e., the first characteristic charge and the second characteristic charge. Then, calculate the battery health status based on the remaining charge, the first characteristic charge, and the second characteristic charge. This allows for the acquisition of the battery health status of the automotive power battery without requiring the battery to be idle.

[0128] In addition, this application also discloses a battery state analysis device, please refer to... Figure 9 , Figure 9This invention discloses a module block diagram of a battery state analysis device according to an embodiment of the present invention. The battery state analysis device can implement the above-described battery state analysis method. The battery state analysis device includes: a voltage data acquisition module 901, a differential voltage acquisition module 902, an inflection point search module 903, a characteristic charge acquisition module 904, and a battery state calculation module 905. The voltage data acquisition module 901, differential voltage acquisition module 902, inflection point search module 903, characteristic charge acquisition module 904, and battery state calculation module 905 are all communicatively connected.

[0129] The voltage data acquisition module 901 acquires the individual cell voltage data of the battery cells. If the individual cell voltage data is higher than a preset individual cell voltage threshold, the differential voltage acquisition module 902 performs differential calculations on the individual cell voltage data to obtain differential voltage data, which includes multiple differential voltage values. The inflection point search module 903 searches for inflection points among the multiple differential voltage values ​​to obtain characteristic inflection points. The characteristic charge acquisition module 904 acquires the integrated charge of the power supply battery based on the characteristic inflection points to obtain characteristic charge. The battery state calculation module 905 performs numerical calculations based on the characteristic charge and a preset standard capacity to obtain the battery health state value.

[0130] It should be noted that the change in discharge current and the current temperature of the power supply battery are acquired separately to obtain the current change value and the current temperature value. The current change value is compared with a preset current change threshold, and the current temperature value is compared with a preset temperature threshold. If the current change value is within the preset current change threshold, a control signal is transmitted to the voltage data acquisition module 901. The voltage data acquisition module 901 acquires the individual cell voltage of each battery cell according to the control signal, obtaining individual cell voltage data including multiple individual cell voltages, and transmits the individual cell voltage data to the differential voltage acquisition module 902. The differential voltage acquisition module 902 compares the individual cell voltage data with a preset individual cell voltage threshold. If the individual cell voltage data is higher than the preset individual cell voltage threshold, the individual cell voltage data is differentiated to obtain differential voltage data including multiple differential voltage values, and the differential voltage data is transmitted to the inflection point search module 903. The inflection point search module 903 searches for inflection points among the multiple differential voltage values, obtains characteristic inflection points, and transmits the characteristic inflection points to the characteristic charge acquisition module 904. The characteristic power acquisition module 904 acquires the integral power of the power supply battery based on the characteristic inflection point, obtains the characteristic power, and transmits the characteristic power to the battery status calculation module 905. The battery status calculation module 905 performs numerical calculations based on the characteristic power and the preset standard capacity to obtain the battery health status value, which can improve the accuracy of obtaining the battery health status of the automotive power battery without requiring the battery to be idle.

[0131] The operation process of the battery state analysis device in this embodiment is specifically described above. Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 The battery state analysis method steps S101 to S105, S201 and S202, S301 to S303, S401 and S402, S501 and S502, S601 and S602 and S701 to S703 are not described in detail here.

[0132] Another embodiment of the present invention discloses a battery state analysis device, comprising: at least one processor, and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform, for example... Figure 1 Control method steps S101 to S105 Figure 2 Control method steps S201 and S202 Figure 3 Control method steps S301 to S303 Figure 4 Control method steps S401 and S402 Figure 5 Control method steps S501 and S502 Figure 6 The control method steps S601 and S602 and Figure 7 The battery state analysis method in steps S701 to S703 of the control method.

[0133] Another embodiment of the present invention discloses a storage medium, the storage medium comprising: storing computer-executable instructions for causing a computer to perform... Figure 1 Control method steps S101 to S105 Figure 2 Control method steps S201 and S202 Figure 3 Control method steps S301 to S303 Figure 4 Control method steps S401 and S402 Figure 5 Control method steps S501 and S502 Figure 6 The control method steps S601 and S602 and Figure 7 The battery state analysis method in steps S701 to S703 of the control method.

[0134] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0135] It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0136] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A battery state analysis method characterized by, The method comprises: acquiring cell voltage data of a battery cell; if the cell voltage data is higher than a preset cell voltage threshold, performing differential calculation on the cell voltage data to obtain differential voltage data; performing inflection point searching on the differential voltage data according to a preset relationship value table to obtain characteristic inflection points, wherein the relationship value table is constructed according to paired data of the differential voltage data and time; the characteristic inflection points include a first characteristic inflection point and a second characteristic inflection point; acquiring integral electric quantity of a power supply battery according to the characteristic inflection points to obtain characteristic electric quantity, wherein the characteristic electric quantity includes a first characteristic electric quantity and a second characteristic electric quantity; performing numerical calculation on the characteristic electric quantity and a preset standard capacity to obtain a battery health state value; the acquiring of the integral electric quantity of the power supply battery according to the characteristic inflection points to obtain the characteristic electric quantity comprises: acquiring an initial point of discharging or charging of the power supply battery; performing integral operation according to the initial point and the first characteristic inflection point to obtain the first characteristic electric quantity, and performing integral operation according to the initial point and the second characteristic inflection point to obtain the second characteristic electric quantity; the performing of the numerical calculation on the characteristic electric quantity and the preset standard capacity to obtain the battery health state value comprises: acquiring a difference value between the first characteristic electric quantity and the second characteristic electric quantity to obtain a capacity difference value; performing numerical calculation on the capacity difference value and the preset standard capacity to obtain the battery health state value; the performing of the numerical calculation on the capacity difference value and the preset standard capacity to obtain the battery health state value comprises: acquiring a difference value of residual electric quantity between the first characteristic inflection point and the second characteristic inflection point to obtain a residual electric quantity difference value; performing division operation on the capacity difference value and the residual electric quantity difference value to obtain an actual capacity; performing division operation on the actual capacity and the preset standard capacity to obtain the battery health state.

2. The battery state analysis method according to claim 1, characterized by, the performing of the differential calculation on the cell voltage data to obtain the differential voltage data comprises: if the cell voltage data is higher than a preset cell voltage threshold, performing differential differential calculation on the cell voltage data in a preset period to obtain the differential voltage data.

3. The battery state analysis method according to claim 1, characterized by, the differential voltage data includes a plurality of differential voltage values, and the performing of the inflection point searching on the differential voltage data according to the preset relationship value table to obtain the characteristic inflection points comprises: acquiring the differential voltage value of a target time of a current period according to the relationship value table to obtain a target voltage value; if the target voltage value is less than a preset voltage threshold, acquiring a previous voltage value and a subsequent voltage value according to the relationship value table; wherein the previous voltage value is the differential voltage value at a preset time before the current time, and the subsequent voltage value is the differential voltage value at a preset time after the current time; performing numerical comparison on the target voltage value, the previous voltage value and the subsequent voltage value to obtain the characteristic inflection points.

4. The battery state analysis method according to claim 3, characterized by, The preset voltage threshold includes a preset first threshold and a preset second threshold, and the numerical comparison of the target voltage value, the previous voltage value and the subsequent voltage value to obtain the feature inflection point includes: If the target voltage value is less than the preset first threshold, and the previous voltage value and the subsequent voltage value are both greater than the target voltage value, the point where the target voltage value is located is taken as the first feature inflection point; If the target voltage value is less than the preset second threshold, and the previous voltage value and the subsequent voltage value are both greater than the target voltage value, the point where the target voltage value is located is taken as the second feature inflection point.

5. A battery state analysis device characterized by comprising: It includes: A voltage data acquisition module for acquiring single cell voltage data of a battery cell; A differential voltage acquisition module for performing differential calculation on the single cell voltage data to obtain differential voltage data if the single cell voltage data is higher than a preset single cell voltage threshold; An inflection point searching module for searching for an inflection point of the differential voltage data according to a preset relationship value table to obtain a feature inflection point; wherein the relationship value table is constructed according to paired data of the differential voltage data and time; and the feature inflection point includes a first feature inflection point and a second feature inflection point; A feature electric quantity acquisition module for acquiring an integral electric quantity of a power supply battery according to the feature inflection point to obtain a feature electric quantity; wherein the feature electric quantity includes a first feature electric quantity and a second feature electric quantity; A battery state calculation module for performing numerical calculation according to the feature electric quantity and a preset standard capacity to obtain a battery health state value; The feature electric quantity acquisition module specifically includes: An initial point of discharging or charging of the power supply battery is acquired; The first feature electric quantity is obtained by integral operation according to the initial point and the first feature inflection point, and the second feature electric quantity is obtained by integral operation according to the initial point and the second feature inflection point; The battery state calculation module specifically includes: A difference value between the first feature electric quantity and the second feature electric quantity is acquired to obtain a capacity difference value; Numerical calculation is performed according to the capacity difference value and the preset standard capacity to obtain the battery health state value; the numerical calculation according to the capacity difference value and the preset standard capacity to obtain the battery health state value includes: A difference value of residual electric quantity between the first feature inflection point and the second feature inflection point is acquired to obtain a residual electric quantity difference value; Division operation is performed on the capacity difference value and the residual electric quantity difference value to obtain an actual capacity; Division operation is performed on the actual capacity and the preset standard capacity to obtain the battery health state.

6. A battery state analysis device characterized by comprising: It includes: At least one processor, and The memory is in communication connection with the at least one processor; wherein The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the battery state analysis method of any one of claims 1 to 4.

7. A computer readable storage medium characterized in that, The computer readable storage medium stores computer executable instructions for causing a computer to execute the battery state analysis method of any one of claims 1 to 4.

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