Battery consistency determination method and related product

Abstract

The embodiment of the invention provides a battery consistency determination method and related products, and the method comprises the steps: determining a voltage difference value corresponding to each frame of data, the voltage difference value being a difference value between the highest cell voltage and the lowest cell voltage in each frame of data; based on the corresponding relation between the voltage difference value corresponding to each frame of data and the battery SOC value in each frame of data, a battery SOC interval is determined, and the voltage difference value corresponding to the battery SOC interval is larger than a set threshold value; and determining the difference value between the upper limit value of the battery SOC interval and the lower limit value of the battery SOC interval as the SOC deviation of the battery, wherein the SOC deviation of the battery is used for measuring the consistency of the battery. According to the embodiment of the invention, the calculation amount for calculating the SOC deviation can be reduced.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly to a method for determining the consistency of a battery and related products. Background Art

[0002] The rise and popularity of electric vehicles have made lithium battery packs a core component of the vehicle power system, and lithium iron phosphate batteries have also become the choice of many battery manufacturers due to their excellent safety performance. However, due to its own electrochemical properties, the state of charge (SOC)-open circuit voltage (OCV) curve of the lithium iron phosphate battery has a plateau region, which makes it very difficult to accurately estimate the charge state of a single cell, and such properties also make the lithium iron phosphate battery often troubled by consistency problems. In order to more effectively manage and maintain the battery system, it is necessary to detect the consistency problem of the cells in a timely manner.

[0003] Currently, the detection method for the consistency problem of cells is mainly the problem caused by the SOC deviation of the cells. Usually, the voltage inflection point on the SOC-OCV curve is found, and the SOC deviation of the battery is obtained by calculating the difference in the state of charge when each cell reaches the inflection point. The current calculation method of SOC deviation requires calculating the state of charge when each cell reaches the inflection point, and the calculation amount is large. Summary of the Invention

[0004] The embodiments of the present application provide a method for determining the consistency of a battery and related products, which can reduce the calculation amount for determining the SOC deviation.

[0005] In a first aspect of the embodiments of the present application, a method for determining the consistency of a battery is provided. The battery includes at least two cells, and the method includes:

[0006] Determine the voltage difference corresponding to each frame of data, where the voltage difference is the difference between the highest cell voltage and the lowest cell voltage in each frame of data;

[0007] Based on the correspondence between the voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, determine a battery SOC interval, where the voltage difference corresponding to the battery SOC interval is greater than a set threshold;

[0008] Determine the difference between the upper limit value and the lower limit value of the battery SOC interval as the SOC deviation of the battery, and the SOC deviation of the battery is used to measure the consistency of the battery.

[0009] Optionally, each frame of data is any preprocessed frame data of the battery within a set time period.

[0010] Optionally, the set time period includes at least one of a discharge period, an AC charging period, and a DC charging period.

[0011] Optionally, the preprocessing includes at least one of sorting by time, removing null values, removing duplicate data, removing invalid values, removing sampling outliers, and removing data that does not conform to the algorithm operating conditions.

[0012] Optionally, after determining the voltage difference corresponding to each frame of data, the method further includes:

[0013] Performing a filtering process on the voltage difference corresponding to each frame of data to obtain a processed voltage difference corresponding to each frame of data;

[0014] Determining a battery SOC interval based on the correspondence between the voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, where the voltage difference corresponding to the battery SOC interval is greater than a set threshold, includes:

[0015] Determining a battery SOC interval based on the correspondence between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, where the processed voltage difference corresponding to the battery SOC interval is greater than a set threshold.

[0016] Optionally, performing a filtering process on the voltage difference corresponding to each frame of data to obtain a processed voltage difference corresponding to each frame of data includes:

[0017] Determining a set of credible voltage differences among the voltage differences corresponding to each frame of data within the set time period;

[0018] Performing polynomial fitting based on the set of credible voltage differences to obtain a fitted voltage difference corresponding to each frame of data within the set time period;

[0019] Performing a filtering process on the fitted voltage difference corresponding to each frame of data within the set time period to obtain a processed voltage difference corresponding to each frame of data.

[0020] Optionally, determining a set of credible voltage differences among the voltage differences corresponding to each frame of data within the set time period includes:

[0021] Based on the correspondence between the voltage difference corresponding to each frame of data and the sampling time point corresponding to each frame of data, obtaining a first curve of the voltage difference corresponding to each frame of data within the set time period changing with time;

[0022] Determine a first curve segment in the first curve where the voltage difference is greater than a first threshold, determine the lower envelope region in the first curve segment, and determine the smallest N voltage differences in the lower envelope region as the set of credible voltage differences corresponding to each frame of data within the set time period, where N is an integer greater than or equal to 2.

[0023] Optionally, the determining the battery SOC interval based on the corresponding relationship between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data includes:

[0024] Based on the corresponding relationship between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, obtain a second curve showing the change of the processed voltage difference with the battery SOC value within the set time period;

[0025] Determine a second curve segment in the second curve where the processed voltage difference is greater than a set threshold, and determine the battery SOC interval corresponding to the second curve segment.

[0026] Optionally, the obtaining a second curve showing the change of the processed voltage difference with the battery SOC value within the set time period based on the corresponding relationship between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data includes:

[0027] Based on the corresponding relationship between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, determine the minimum value among at least two processed voltage differences corresponding to the same battery SOC value as the processed voltage difference corresponding to the same battery SOC value;

[0028] Based on the processed voltage differences corresponding to each different battery SOC value, obtain a second curve showing the change of the processed voltage difference with the battery SOC value within the set time period.

[0029] Optionally, after obtaining the SOC deviation of the battery, the method further includes:

[0030] Upload the SOC deviation of the battery to the cloud server.

[0031] Optionally, the set threshold is greater than the difference between the upper limit and the lower limit of the voltage fluctuation range in the first platform region, and the set threshold is greater than the difference between the upper limit and the lower limit of the voltage fluctuation range in the second platform region, and the set threshold is less than the absolute value of the difference between the upper limit of the voltage fluctuation range in the first platform region and the lower limit of the voltage fluctuation range in the second platform region. The first platform region and the second platform region are two adjacent platform regions in the SOC-OCV curve of the battery.

[0032] Optionally, the SOC-OCV curve of the battery includes a small platform region, a first large platform region, and a second large platform region. The SOC value of the first large platform region is greater than the SOC value of the small platform region and less than the SOC value of the second large platform region. The first platform region is one of the first large platform region and the second large platform region, and the second platform region is the other of the first large platform region and the second large platform region.

[0033] In a second aspect of the embodiments of the present application, there is provided a device for determining the consistency of a battery. The battery includes at least two battery cells, and the device includes:

[0034] A determination unit, configured to determine the voltage difference corresponding to each frame of data, where the voltage difference is the difference between the highest battery cell voltage and the lowest battery cell voltage in each frame of data;

[0035] The determination unit is further configured to determine a battery SOC interval based on the correspondence between the voltage difference corresponding to each frame of data and the battery SOC in each frame of data, where the voltage difference corresponding to the battery SOC interval is greater than a set threshold;

[0036] The determination unit is further configured to determine that the difference between the upper limit value and the lower limit value of the battery SOC interval is the SOC deviation of the battery, and the SOC deviation of the battery is used to measure the consistency of the battery.

[0037] In a third aspect of the embodiments of the present application, there is provided a server. The server includes a first communication module and a processing module. The first communication module is configured to communicate with the power device where the battery is located to receive each frame of data, and the processing module is configured to execute the step instructions in the first aspect of the embodiments of the present application.

[0038] Optionally, when the SOC deviation is greater than a preset warning threshold, the processing module is further configured to send a warning signal to the power device through the first communication module.

[0039] In a fourth aspect of the embodiments of the present application, there is provided a power device. The power device includes a battery and a second communication module. The second communication module is configured to send each frame of data of the battery to the server, so that the server executes the step instructions in the first aspect of the embodiments of the present application according to each frame of data.

[0040] In a fifth aspect of the embodiments of the present application, there is provided a power device. The power device includes a battery and a processing component. The processing component is configured to execute the step instructions in the first aspect of the embodiments of the present application according to each frame of data of the battery.

[0041] Optionally, the electrical energy device includes a warning component, and the processing component is further configured to trigger the warning component to send a warning message and / or send a warning prompt message to a third-party device when the SOC deviation is greater than a preset warning threshold.

[0042] A sixth aspect of the embodiments of the present application provides an electronic device, including a processor and a memory. The memory is used to store a computer program, and the computer program includes program instructions. The processor is configured to call the program instructions to execute the step instructions in the first aspect of the embodiments of the present application.

[0043] A seventh aspect of the embodiments of the present application provides a computer-readable storage medium. The computer-readable storage medium stores a computer program for electronic data exchange. The computer program enables a computer to execute some or all of the steps described in the first aspect of the embodiments of the present application.

[0044] An eighth aspect of the embodiments of the present application provides a computer program product. The computer program product includes a computer program, and the computer program is operable to enable a computer to execute some or all of the steps described in the first aspect of the embodiments of the present application. The computer program product can be a software installation package.

[0045] A ninth aspect of the embodiments of the present application provides a processor. The processor is configured to call program instructions to execute the step instructions in the first aspect of the embodiments of the present application. The processor can include any one of a chip, an integrated circuit, a micro control unit (MCU), and a computer terminal.

[0046] In the embodiments of the present application, a voltage difference corresponding to each frame of data is determined. The voltage difference is the difference between the highest cell voltage and the lowest cell voltage in each frame of data. Based on the correspondence between the voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, a battery SOC interval is determined, and the voltage difference corresponding to the battery SOC interval is greater than a set threshold. The difference between the upper limit value and the lower limit value of the battery SOC interval is determined as the SOC deviation of the battery, and the SOC deviation of the battery is used to measure the consistency of the battery. In the embodiments of the present application, based on the correspondence between the voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, a battery SOC interval is determined, and the difference between the upper limit value and the lower limit value of the battery SOC interval is determined as the SOC deviation of the battery. In the process of determining the SOC deviation of the battery, only the battery SOC value is required, and it is not necessary to calculate the SOC value of each cell, which can reduce the calculation amount of determining the SOC deviation, thereby quickly determining the consistency of the battery. Description of the Drawings

[0047] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0048] Figure 1 It is a schematic diagram of the SOC-OCV curve of a lithium iron phosphate battery provided by an embodiment of the present application;

[0049] Figure 2 It is a schematic flowchart of a method for determining the consistency of batteries provided by an embodiment of the present application;

[0050] Figure 3 It is a schematic diagram of the corresponding relationship between the voltage difference corresponding to each frame of data and the battery SOC value in each frame of data provided by an embodiment of the present application;

[0051] Figure 4 It is a schematic flowchart of another method for determining the consistency of batteries provided by an embodiment of the present application;

[0052] Figure 5 It is a schematic diagram of a first curve of the voltage difference varying with time provided by an embodiment of the present application;

[0053] Figure 6 It is a schematic diagram of a second curve of the voltage difference varying with the battery SOC value provided by an embodiment of the present application;

[0054] Figure 7 It is a schematic flowchart of the specific process of a method for determining the consistency of batteries provided by an embodiment of the present application;

[0055] Figure 8 It is a schematic structural diagram of a device for determining the consistency of batteries provided by an embodiment of the present application;

[0056] Figure 9 It is a schematic structural diagram of an electronic device provided by an embodiment of the present application;

[0057] Figure 10 It is a schematic structural diagram of a server provided by an embodiment of the present application;

[0058] Figure 11 It is a schematic structural diagram of an electric energy device provided by an embodiment of the present application. Detailed implementation manners

[0059] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0060] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products or devices.

[0061] Referring to "embodiments" in the present application means that the specific features, structures or characteristics described in connection with the embodiments may be included in at least one embodiment of the present application. The phrase appears in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described in the present application may be combined with other embodiments.

[0062] In an electric vehicle, in order to accurately obtain the state of charge (SOC) of a battery cell, generally, through the state of charge (SOC)-open circuit voltage (OCV) curve, by sampling the open circuit voltage of the battery cell, and then obtaining the SOC of the battery cell according to the OCV-SOC mapping relationship in the SOC-OCV curve. The SOC-OCV curve can also be simply referred to as the OCV curve.

[0063] For lithium iron phosphate (chemical formula: LiFePO4, abbreviated as LFP) batteries, due to their own electrochemical properties, there is a plateau region in their SOC-OCV, which makes it very difficult to accurately estimate the charge state of a single battery cell, and such a property also often causes problems with the consistency of lithium iron phosphate batteries. In order to more effectively manage and maintain the battery system, it is necessary to detect the consistency problem of the battery cells in a timely manner. At present, the detection method for the consistency problem of battery cells is mainly the problem caused by the SOC deviation of the battery cells. Usually, the voltage inflection point on the SOC-OCV curve is found, and the SOC deviation of the battery is obtained by calculating the difference in the state of charge when each battery cell reaches the inflection point. The current calculation method of SOC deviation requires calculating the state of charge when each battery cell reaches the inflection point, and the calculation amount is large.

[0064] The calculation algorithm for the SOC deviation in the embodiments of the present application determines the battery SOC interval based on the correspondence between the voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, and determines that the difference between the upper limit value and the lower limit value of the battery SOC interval is the SOC deviation of the battery. Only the battery SOC value is required, and it is not necessary to calculate the SOC value of each battery cell, which can reduce the calculation amount for determining the SOC deviation, thereby quickly determining the consistency of the battery.

[0065] Please refer to Figure 1 , Figure 1 which is a schematic diagram of the SOC-OCV curve of a lithium iron phosphate battery provided by the embodiments of the present application. As Figure 1 shown, the abscissa is the SOC value, and the ordinate is the value of the open circuit voltage OCV. From Figure 1 it can be seen that when the open circuit voltage of the battery cell is obtained, the corresponding SOC value can be obtained according to the SOC-OCV curve.

[0066] From Figure 1 the SOC-OCV curve of lithium iron phosphate LFP, it can be known that the SOC-OCV curve of the lithium iron phosphate battery is non-linear, with a small plateau region and two large plateau regions. If the battery cells in the highest state (the state, that is, the state of charge) and the lowest state are in the same inner plateau region at the same time, the voltage difference obtained from the voltage of the battery cell in the highest state and the voltage of the battery cell in the lowest state will be very small. As the electric device discharges or charges, the battery cells in the highest state and the lowest state will successively pass through the inflection points of 2 large plateau regions (such as the large plateau region 1 and large plateau region 2 shown in Figure 1 ) (such as the inflection point 2 in Figure 1 ). When calculating the change amount of the battery SOC in the state where the battery cell in the high state is in the high voltage plateau and the battery cell in the low state is in the low voltage plateau, the consistency gap of the battery cells can be calculated. Figure 1 contains two inflection points: inflection point 1 and inflection point 2. Inflection point 1 is the inflection point with a lower state of charge, and inflection point 2 is the inflection point with a higher state of charge.

[0067] Among them, the electric device can be a device driven by electric energy. For example, the electric device can include any one of a vehicle, an aircraft, a ship, and an energy storage cabinet.

[0068] It should be noted that Figure 1 is only a possible example of an SOC-OCV curve. The SOC-OCV curve can also use OCV as the abscissa and the SOC value as the ordinate.

[0069] Please refer to Figure 2 , Figure 2 which is a schematic flow chart of a method for determining the consistency of a battery provided by the embodiments of the present application. As Figure 2As shown, the method for determining the consistency of the battery includes the following steps.

[0070] 201, the electronic device determines the voltage difference corresponding to each frame of data, and the voltage difference is the difference between the highest cell voltage and the lowest cell voltage in each frame of data.

[0071] The electronic device can be any device with computing power and communication capabilities. For example, the electronic device can be a cloud server. The electronic device can be a cloud server for calculating the battery SOC deviation.

[0072] In the embodiments of the present application, the voltage difference is equal to the highest cell voltage minus the lowest cell voltage in each frame of data.

[0073] Each frame of data is the state data of the battery sampled within each sampling period. The battery may include at least two cells, and the state data of the battery may include: the voltages of the at least two cells, the cell numbers of the at least two cells, battery SOC, and other data. For example, if the sampling period is 30 seconds, each frame of data includes the voltages of at least two cells of the battery sampled within 30 seconds, the cell numbers of at least two cells, battery SOC, and other data. The frame data may exist in the form of a data frame or in any form that can carry the state data of the battery, such as a data sequence, and the embodiments of the present application do not make a limitation.

[0074] Each frame of data may include the highest cell voltage, the lowest cell voltage, and the battery SOC. The battery may be formed by connecting at least two cells in series. The highest cell voltage of each frame of data is the voltage of the cell with the highest sampled cell voltage among all the cells of the battery within the sampling period of each frame of data (for example, the sampling period may be 30 seconds). The lowest cell voltage of each frame of data is the voltage of the cell with the lowest sampled cell voltage among all the cells of the battery within the sampling period of each frame of data.

[0075] For example, the battery may include 120 cells, and each frame of data may include the voltage of the cell with the highest sampled voltage (the highest cell voltage), the voltage of the cell with the lowest sampled voltage (the lowest cell voltage), and the battery SOC among the 120 cells within the sampling period corresponding to the frame of data.

[0076] It should be noted that the battery SOC is different from the cell SOC. The battery SOC is the overall SOC of the battery, and the cell SOC is the SOC of the cell itself.

[0077] Among them, each frame of data may further include the cell number of the cell with the highest voltage and the cell number of the cell with the lowest voltage among multiple cells.

[0078] Optionally, each frame of data is any preprocessed frame data of the battery within a set time period.

[0079] In the embodiments of the present application, each frame of data in step 201 is preprocessed frame data.

[0080] The electronic device can obtain all the original frame data uploaded by the same vehicle during a set period, process each original frame data uploaded by the same vehicle during the set period, and obtain each frame of data in step 201.

[0081] Exemplarily, the set period is 72 hours. The same vehicle can periodically sample the original state data of the battery of the vehicle according to a set sampling period, and report the original state data of the battery to the electronic device in the form of original frame data. The set sampling period can be set in advance, and the set sampling period can be set to any value within 1 to 100 seconds. For example, it can be set to 30 seconds. Then, within the set period of 72 hours, a total of 8640 (72 * 60 * 2) original frame data reported by the same vehicle can be received. The original state data of the battery may include: the original voltages of at least two battery cells of the battery, the original cell numbers of the at least two battery cells, the original SOC of the battery, and other data.

[0082] Optionally, the set period includes at least one of a discharging period, an AC charging period, and a DC charging period.

[0083] Optionally, the set period includes at least one of a discharging period and an AC charging period.

[0084] In the embodiments of the present application, the SOC deviation of the battery can be calculated according to the frame data reported by the battery during the discharging period, and the SOC deviation of the battery can also be calculated according to the frame data reported by the battery during the AC charging stage. The SOC deviation of the battery can also be calculated according to the frame data reported by the battery during the discharging period and the AC charging stage. The method for determining the consistency of the battery in the embodiments of the present application can be used for discharging conditions and can also be used for AC charging conditions.

[0085] The embodiments of the present application can be applied to the inflection point prediction and SOC deviation calculation during the discharging period or the AC charging period. Since each vehicle will have a discharging period to ensure there are enough frame data, through the method for determining the consistency of the battery in the embodiments of the present application, the SOC deviations of all vehicles can be accurately calculated.

[0086] Among them, the set period may include data in the set SOC value range of the battery SOC during the discharging period and the AC charging period. The set SOC value range can be set in advance. The set SOC value range may include Figure 1A part of the large platform area 1, a part of the large platform area 2, and the inflection point 2 between the large platform area 1 and the large platform area 2. For example, the set SOC value range can be 50% to 90%. On the one hand, in this set SOC value range, the frequency of data appearance is very high, so there is enough data to calculate the SOC deviation, and the electronic device can quickly obtain the calculation result of the SOC deviation. On the other hand, in this set SOC value range, there is only one frequently occurring inflection point (such as Figure 1 the inflection point 2 shown), when calculating the SOC deviation, it will not be interfered by another inflection point (such as Figure 1 the inflection point 1 shown), and compared with the short duration of the small platform area of the data near the inflection point 1, near the inflection point 2 in this set SOC value range, the durations of the large platform area 1 and the large platform area 2 are relatively long, the amount of data in this set SOC value range is more, and the credibility of the data is relatively higher. Based on the data in this set SOC value range, the accuracy of the calculated SOC deviation is relatively higher. Thus, the SOC deviation can be calculated quickly and accurately.

[0087] When the battery is charging, when the highest voltage-saving battery cell is full, all battery cells will no longer be charged (nor will the lowest voltage-saving one), so at this time, the SOC of the lowest voltage-saving battery cell may be above 90%, but it will not be 100%. For the data above 90%, the data at this time is not credible. There will be a large voltage difference.

[0088] In addition, 50% to 90% is data with a very high frequency. In the actual charge and discharge working conditions, the probability of encountering Figure 1 the inflection point 1 in [reference] is lower than the probability of encountering the inflection point 2, so a section of data including the high-probability inflection point 2 is selected.

[0089] Optionally, the preprocessing includes at least one of: sorting by time, removing null values, removing duplicate data, removing invalid values, removing sampling outliers, and removing data that does not conform to the algorithm working conditions.

[0090] Sorting by time: Each original data frame uploaded by the same vehicle contains the sampling time point of the original data frame. It can be sorted in time according to the sampling time point of each original data frame.

[0091] Removing null values: Some fields in the original data frame may have no data. For example, if the value of the field corresponding to the battery SOC is "None" or "empty", it indicates that there is a null value in the original data frame, and the original data frame with the null value can be removed.

[0092] Removing duplicate data: If the same data appears twice or more in the original data frame, the repeatedly appearing data is removed, and only one data is retained.

[0093] Removing invalid values: Invalid values are data that are clearly inconsistent with the facts. For example, the highest cell voltage is 2.4V and the lowest cell voltage is 3.2V. The original data frame with such invalid values can be removed.

[0094] Removing sampling outliers: Sampling outliers are values that are not within the range corresponding to the parameters. For example, the range of the SOC value is 0 - 100%. If the SOC value in the reported original data frame is -10, it is a sampling outlier, and the original data frame with such a sampling outlier can be removed.

[0095] Removing data that does not conform to the algorithm working conditions: For example, during the DC charging period, the method for determining the consistency of the battery in the embodiments of the present application is not applicable, and the data during the DC charging period can be removed.

[0096] In the embodiments of the present application, the original data frame can be pre - processed to obtain frame data.

[0097] 202, the electronic device determines the battery SOC interval based on the correspondence between the voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, and the voltage difference corresponding to the battery SOC interval is greater than the set threshold.

[0098] In the embodiments of the present application, each frame of data has a battery SOC value, and each frame of data corresponds to a voltage difference. The correspondence between the voltage difference corresponding to each frame of data and the battery SOC value in each frame of data can be established according to the voltage difference corresponding to each frame of data and the battery SOC value in each frame of data. This correspondence can include a set of relationship pairs. The set of relationship pairs includes multiple relationship pairs, and each relationship pair includes a voltage difference and a corresponding battery SOC value. The set of relationship pairs can be stored in the memory of the electronic device (such as a non - volatile memory). The target set of relationship pairs with a voltage difference greater than the set threshold can be determined from the set of relationship pairs, and the interval of the SOC values in the target set of relationship pairs is the battery SOC interval.

[0099] For example, within a set time period, there are 10,000 frames of data. The correspondence between the voltage difference corresponding to each frame of data and the battery SOC value in each frame of data can be established according to the voltage difference corresponding to each frame of data and the battery SOC value in each frame of data. Exemplarily, the voltage differences corresponding to different battery SOC values within the range of the battery SOC value from 50% to 90% can be obtained, and the SOC interval corresponding to the voltage difference greater than the set threshold can be determined.

[0100] Please refer to Figure 3 , Figure 3 is a schematic diagram of the correspondence between the voltage difference corresponding to each frame of data and the battery SOC value in each frame of data provided by the embodiments of the present application. As Figure 3As shown, the abscissa is the battery SOC value, and the ordinate is the voltage difference value. The SOC interval corresponding to the voltage difference value greater than the set threshold can be determined. For example, Figure 3 As shown, the lower limit value of this SOC interval is SOC1, and the upper limit value of this SOC interval is SOC2.

[0101] 203. The electronic device determines that the difference between the upper limit value and the lower limit value of the battery SOC interval is the SOC deviation of the battery, and the SOC deviation of the battery is used to measure the consistency of the battery.

[0102] In the embodiment of the present application, the lower limit value of the SOC interval can be understood as the battery SOC value (for example, it can be denoted as SOC1) when the battery cell with the highest voltage in the battery passes through the inflection point (for example, the inflection point 2 between Figure 1 ). The upper limit value of the SOC interval can be understood as the battery SOC value (for example, it can be denoted as SOC2) when the battery cell with the lowest voltage in the battery passes through the inflection point (for example, the inflection point 2 between Figure 1 ). Subtracting SOC2 - SOC1 can obtain the SOC deviation of the battery.

[0103] In the embodiment of the present application, the absolute value of the difference between the upper limit value and the lower limit value of the battery SOC interval can be used as the SOC deviation of the battery.

[0104] The SOC deviation of the battery is used to measure the consistency of the battery, and the SOC deviation of the battery is an important standard for measuring the consistency of the battery. Generally speaking, the smaller the SOC deviation of the battery, the better the consistency of the battery, and the larger the SOC deviation of the battery, the worse the consistency of the battery.

[0105] In the embodiment of the present application, based on the correspondence between the voltage difference value corresponding to each frame of data and the battery SOC value in each frame of data, the battery SOC interval is determined, and the difference between the upper limit value and the lower limit value of the battery SOC interval is determined as the SOC deviation of the battery. Only the battery SOC value is required in the process of determining the SOC deviation of the battery, and it is not necessary to calculate the SOC value of each battery cell, which can reduce the calculation amount of determining the SOC deviation, so as to quickly determine the consistency of the battery.

[0106] Please refer to Figure 4 , Figure 4 which is a schematic flowchart of another method for determining the consistency of a battery provided by the embodiment of the present application. As shown in Figure 4 the method for determining the consistency of the battery includes the following steps.

[0107] 401. The electronic device determines the voltage difference value corresponding to each frame of data, and this voltage difference value is the difference between the highest battery cell voltage and the lowest battery cell voltage in each frame of data.

[0108] 402. The electronic device filters the voltage difference corresponding to each frame of data to obtain the processed voltage difference corresponding to each frame of data.

[0109] In the embodiment of the present application, since the highest cell voltage and the lowest cell voltage in each frame of data are sampled within the same sampling period (for example, the sampling period can be set to 30 seconds), within this sampling period, there will be a certain difference in the voltage sampling time points of each cell. If the battery discharges rapidly (for example, when an electric vehicle is climbing a slope) or charges (for example, when an electric vehicle is braking suddenly) within this sampling period, if the difference in the voltage sampling time points of the cells is relatively large (if the sampling period is 30 seconds, the maximum difference is 30 seconds), then there will be a certain deviation between the voltage difference between the highest cell voltage and the lowest cell voltage in each frame of data and the true voltage difference.

[0110] In the embodiment of the present application, by filtering the voltage difference corresponding to the frame data, the processed voltage difference corresponding to each frame of data can be obtained, so that the processed voltage difference corresponding to each frame of data can be closer to the true voltage difference, thereby improving the calculation accuracy of the SOC deviation.

[0111] Optionally, step 402 may specifically include the following steps:

[0112] (11) The electronic device determines a set of credible voltage differences among the voltage differences corresponding to each frame of data within the set time period;

[0113] (12) The electronic device performs polynomial fitting based on the set of credible voltage differences to obtain the fitted voltage difference corresponding to each frame of data within the set time period;

[0114] (13) The electronic device filters the fitted voltage difference corresponding to each frame of data within the set time period to obtain the processed voltage difference corresponding to each frame of data.

[0115] In the embodiment of the present application, the electronic device can determine a set of credible voltage differences among the voltage differences corresponding to each frame of data within the set time period. Due to the possible difference in the sampling time of each cell, there will be a certain deviation between the voltage difference between the highest cell voltage and the lowest cell voltage in each frame of data and the true voltage difference. A set of credible voltage differences among the voltage differences corresponding to each frame of data within the set time period can be found. Polynomial fitting can be performed based on the set of credible voltage differences to obtain the fitted voltage difference corresponding to each frame of data within the set time period, and the fitted voltage difference corresponding to each frame of data within the set time period is filtered to obtain the processed voltage difference corresponding to each frame of data.

[0116] Exemplarily, within a certain sampling period, for example, battery cell 1 and battery cell 2 are respectively the battery cell with the highest voltage and the battery cell with the lowest voltage. The voltages of these two battery cells may not be sampled at the same moment. At the inflection point, there is a minimum value theory, that is, if the sampling times of the battery cell with the highest voltage and the battery cell with the lowest voltage are different, then the voltage difference calculated based on the voltage of the battery cell with the highest voltage and the voltage of the battery cell with the lowest voltage has a high probability of being larger than the actual voltage difference. Based on this minimum value theory, the embodiments of the present application can select the smaller voltage difference among the voltage differences in the inflection point region corresponding to each frame of data within a set time period as the credible voltage difference set, thereby increasing the credibility of the credible voltage difference set.

[0117] Regarding the minimum value theory, it can be illustrated by an example. Please refer to Table 1, which is a table of the actual voltage difference and the sampled and calculated voltage difference of three battery cells provided by the embodiments of the present application.

[0118] Table 1

[0119]

[0120] Among them, the sampled and calculated voltage difference is the difference between the voltage of the battery cell with the highest voltage and the voltage of the battery cell with the lowest voltage among the three battery cells. The first sampling time point, the second sampling time point, and the third sampling time point are three possible sampling time points within the sampling period, and these three sampling time points are different. As shown in Table 1, the probability of being less than 2 is 7 / 27, which is relatively small, and the probability of being greater than 2 is 11 / 27, which is relatively large. The probability that the sampled and calculated voltage difference is greater than the actual voltage difference is greater than the probability that the sampled and calculated voltage difference is less than the actual voltage difference. Table 1 is only an example. In actual battery products, the number of battery cells in the battery is much larger than 3, so that the probability that the sampled and calculated voltage difference is greater than the actual voltage difference is much greater than the probability that the sampled and calculated voltage difference is less than the actual voltage difference.

[0121] The electronic device can perform polynomial fitting based on the credible voltage difference set to obtain the fitted voltage difference corresponding to each frame of data within the set time period. In the credible voltage difference set, each credible voltage difference corresponds to a frame of data, and each frame of data carries a sampling time point to indicate the sampling time of the frame of data. The sampling time of the frame of data can be a time point within the sampling period of the frame of data. In the credible voltage difference set, each credible voltage difference corresponds to a sampling time point, and each credible voltage difference and the corresponding sampling time point can form a credible data point set.

[0122] Embodiments of the present application can use polynomial regression to perform polynomial fitting. For example, the polynomial can be set as F(t) = at n + bt n-1 + … + C. Where n is the number of terms of the polynomial, and a, b, c are parameters to be fitted. t is time, and t can be the sampling time point of each frame of data. F(t) is the fitted polynomial, and F(t) represents the fitted voltage difference at different time points. F(t) can be a fitted curve with time as the abscissa and the fitted voltage difference as the ordinate. The polynomial curve F(t) can pass through all the reliable data points in the set of reliable data points, and then minimize the loss of F(t) to obtain the well-fitted polynomial curve. It should be noted that the number of reliable data points in the set of reliable data points should be greater than n to be able to fit the polynomial curve.

[0123] The electronic device can filter the fitted voltage difference corresponding to each frame of data within the set time period to obtain the processed voltage difference corresponding to each frame of data. After obtaining the well-fitted polynomial curve, the fitted voltage difference corresponding to each time point can be obtained according to the well-fitted polynomial curve, and then the fitted voltage difference corresponding to each frame of data within the set time period can be obtained.

[0124] Since at the inflection point, there is a minimum value theory, that is, if the sampling times of the battery cells with the highest voltage and the battery cells with the lowest voltage are different, then the voltage difference calculated based on the voltages of the battery cells with the highest voltage and the battery cells with the lowest voltage will have a high probability of being larger than the true voltage difference. However, there will also be a small probability situation: the voltage difference calculated based on the voltages of the battery cells with the highest voltage and the battery cells with the lowest voltage may be smaller than the true voltage difference. This will cause a small number of outliers in the set of reliable voltage differences. To avoid the influence of these outliers, the electronic device can filter the fitted voltage difference corresponding to each frame of data within the set time period to obtain the processed voltage difference corresponding to each frame of data, so that the processed voltage difference corresponding to each frame of data is closer to the true voltage difference. Exemplarily, a filtering algorithm can be used to filter the fitted voltage difference corresponding to each frame of data within the set time period to filter out noise (i.e., remove outliers in the fitted voltage difference) to obtain the processed voltage difference corresponding to each frame of data. For example, the filtering algorithm can be a Butterworth low-pass filtering algorithm. The filter of this filtering algorithm can use a finite impulse response (FIR) filter. The FIR filter is a digital filter and is a process of convolution in the time domain, and can directly perform filtering in the time domain. This filtering algorithm can also convert the time-domain data into the frequency domain and perform low-pass filtering in the frequency domain.

[0125] Optionally, step (11) may specifically include the following steps:

[0126] (111) The electronic device obtains a first curve of the voltage difference corresponding to each frame of data changing with time within the set time period based on the correspondence between the voltage difference corresponding to each frame of data and the sampling time point corresponding to each frame of data;

[0127] (112) The electronic device determines a first curve segment in the first curve where the voltage difference is greater than a first threshold, determines the lower envelope region in the first curve segment, and determines the smallest N voltage differences in the lower envelope region as the set of reliable voltage differences corresponding to each frame of data within the set time period, where N is an integer greater than or equal to 2.

[0128] Steps (111) and (112) are methods for determining the set of reliable voltage differences.

[0129] Based on the above minimum value theory, at the inflection point, if the sampling times of the battery cells with the highest voltage and the lowest voltage are different, then the voltage difference calculated based on the voltage of the battery cell with the highest voltage and the voltage of the battery cell with the lowest voltage will very likely be larger than the actual voltage difference. Since the voltage difference at the inflection point is relatively large, a first curve segment with a relatively large voltage difference can be selected through the first threshold, the lower envelope region in the first curve segment can be determined, and the smallest N voltage differences in the lower envelope region can be determined as the set of reliable voltage differences corresponding to each frame of data within the set time period.

[0130] Optionally, the first curve does not represent the actual curve, but the correspondence between the voltage difference corresponding to each frame of data and the time point within the set time period.

[0131] The lower envelope region in the first curve segment refers to the adjacent downward trend region and upward trend region existing in the first curve segment. Among them, the downward trend region is the region where the downward amplitude exceeds a second threshold, and the upward trend region is the region where the upward amplitude exceeds the second threshold. The second threshold can be set in advance. The lower envelope region includes the adjacent downward trend region and upward trend region.

[0132] The first threshold can be set in advance. The first threshold is greater than the difference between the upper limit and the lower limit of the voltage fluctuation range of the first plateau region, and the first threshold is greater than the difference between the upper limit and the lower limit of the voltage fluctuation range of the second plateau region, and the first threshold is less than the absolute value of the difference between the upper limit of the voltage fluctuation range of the first plateau region and the lower limit of the voltage fluctuation range of the second plateau region. The first plateau region and the second plateau region are two adjacent plateau regions in the SOC-OCV curve of the battery, and the upper limit of the voltage fluctuation range of the first plateau region is less than the lower limit of the voltage fluctuation range of the second plateau region. For example, the first plateau region can be Figure 1 the large plateau region 1 in the SOC-OCV curve of Figure 1 and the second plateau region can be the large plateau region 2 in the SOC-OCV curve of

[0133] Please refer to Figure 5 , Figure 5 which is a schematic diagram of a first curve showing the change of voltage difference over time provided by an embodiment of the present application. As shown in Figure 5 , in the set time period shown, for the first curve of the voltage difference corresponding to each frame of data changing with time, the abscissa is time and the ordinate is the voltage difference. As the first curve changes with time, the voltage difference changes within the range of 0 to 50 mV. It should be noted that this first curve is obtained based on multiple frames of data. The first curve is composed of multiple discrete data points. The time on the abscissa of this first curve is a discrete value, that is, the sampling time point of each frame of data. The voltage difference on the ordinate of the first curve is also a discrete value. Figure 5 The bold curve in Figure 5 is the first curve segment in the first curve where the voltage difference is greater than the first threshold. Taking the first threshold of 25 mV in Figure 5 as an example. It can be seen from the first curve segment that there is a lower envelope region in this first curve segment, and within this lower envelope region, the voltage difference is relatively small. It can be determined that the smallest N voltage differences among all discrete data points in the lower envelope region are the set of credible voltage differences. Where N can be greater than the number of terms of polynomial fitting. N is greater than the number of terms n of polynomial fitting.

[0134] 403, the electronic device determines the battery SOC interval based on the corresponding relationship between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, and the processed voltage difference corresponding to the battery SOC interval is greater than the set threshold.

[0135] In the embodiments of the present application, in each frame of data, there is a battery SOC value, and each frame of data corresponds to a processed voltage difference. A corresponding relationship between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data can be established. This corresponding relationship may include a set of relationship pairs. The set of relationship pairs includes multiple relationship pairs, and each relationship pair includes a processed voltage difference and a corresponding battery SOC value. This set of relationship pairs can be stored in the memory of the electronic device (such as a non-volatile memory). A target set of relationship pairs with a processed voltage difference greater than a set threshold can be determined from this set of relationship pairs, and the interval of the SOC value in the target set of relationship pairs is determined as the battery SOC interval.

[0136] Optionally, step 403 may specifically include the following steps:

[0137] (21) The electronic device obtains a second curve of the change of the processed voltage difference with the battery SOC value within the set period based on the corresponding relationship between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data;

[0138] (22) The electronic device determines a second curve segment in the second curve where the processed voltage difference is greater than the set threshold, and determines the battery SOC interval corresponding to the second curve segment.

[0139] In the embodiments of the present application, there is a one-to-one correspondence between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data. A second curve of the change of the processed voltage difference with the battery SOC value within the set period can be obtained according to this corresponding relationship.

[0140] Optionally, the second curve is not limited to being represented in the form of a real curve, and may also be the corresponding relationship or functional relationship between the processed voltage difference and the battery SOC value within the set period.

[0141] Please refer to Figure 6 , Figure 6 which is a schematic diagram of a second curve of the change of the voltage difference with the battery SOC value provided by the embodiments of the present application. As Figure 6 shown in the second curve of the change of the processed voltage difference with the battery SOC value within the set period, the abscissa is the battery SOC value, and the ordinate is the voltage difference. As the battery SOC value changes, the voltage difference changes within the range of 0 to 50 mV. It should be noted that this second curve is obtained based on multiple frames of data. The second curve is composed of multiple discrete data points. The time of the abscissa of this second curve is a discrete value, which is the SOC value of each frame of data. The voltage difference of the ordinate of the second curve is also a discrete value.Figure 6 The bold curve in Figure 6 is the second curve segment in the second curve where the voltage difference is greater than the set threshold value. Taking 25 mV as an example for the set threshold value in

[0142] Optionally, step (21) may specifically include the following steps:

[0143] (211) The electronic device determines the minimum value among at least two processed voltage differences corresponding to the same battery SOC value as the processed voltage difference corresponding to the same battery SOC value based on the correspondence between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data;

[0144] (212) The electronic device obtains a second curve of the processed voltage difference varying with the battery SOC value within the set time period based on the processed voltage differences corresponding to each different battery SOC value.

[0145] In the embodiments of the present application, since there are a large number of frame data within the set time period, there may be a situation where the battery SOC values of two or more frame data are the same (for example, during the discharge condition, when the vehicle is stopped waiting for a traffic light, the battery SOC value hardly changes, and the battery SOC values of several consecutive frames of data may be the same). During the process of generating the second curve, only one voltage difference needs to be taken for the same battery SOC value. In the embodiments of the present application, the minimum value among at least two processed voltage differences corresponding to the same battery SOC value is determined as the processed voltage difference corresponding to the same battery SOC value, and the value with the smallest voltage difference is selected. Based on the above minimum value theory, it is possible to make the processed voltage difference corresponding to the same battery SOC value have a higher probability of approaching the true voltage difference. Thereby improving the accuracy of the second curve of the voltage difference varying with the battery SOC value, and further improving the accuracy of the calculation result of the SOC deviation of the battery.

[0146] Optionally, the set threshold value is greater than the difference between the upper limit value and the lower limit value of the voltage fluctuation range of the first plateau region, and the set threshold value is greater than the difference between the upper limit value and the lower limit value of the voltage fluctuation range of the second plateau region, and the set threshold value is less than the absolute value of the difference between the upper limit value of the voltage fluctuation range of the first plateau region and the lower limit value of the voltage fluctuation range of the second plateau region. The first plateau region and the second plateau region are two adjacent plateau regions in the SOC-OCV curve of the battery, and the upper limit value of the voltage fluctuation range of the first plateau region is less than the lower limit value of the voltage fluctuation range of the second plateau region. For example, the first plateau region may be Figure 1in the SOC-OCV curve of, the large flat region 1, and the second flat region can be Figure 1 the large flat region 2 in the SOC-OCV curve of. Exemplarily, in the first flat region, if the voltage of the battery cell fluctuates within 3.295 - 3.305V, and in the second flat region, if the voltage of the battery cell fluctuates within 3.345 - 3.355V. Then the set threshold can be set to a value greater than 10mV and less than 40mV. For example, the set threshold can be set to 25mV.

[0147] Among them, the set threshold and the first threshold can be set to the same value or different values.

[0148] Optionally, the SOC-OCV curve of the battery includes a small flat region, a first large flat region, and a second large flat region. The SOC value of the first large flat region is greater than the SOC value of the small flat region and less than the SOC value of the second large flat region; the first flat region is one of the first large flat region and the second large flat region, and the second flat region is the other of the first large flat region and the second large flat region. Exemplarily, the first large flat region can be Figure 1 the large flat region 1 in the SOC-OCV curve of, and the first large flat region can be Figure 1 the large flat region 2 in the SOC-OCV curve of.

[0149] 404. The electronic device determines that the difference between the upper limit value and the lower limit value of the battery SOC interval is the SOC deviation of the battery, and the SOC deviation of the battery is used to measure the consistency of the battery.

[0150] Among them, for the specific implementation of step 401 and step 404, reference can be made to the above-mentioned step 201 and step 203, which will not be elaborated here.

[0151] Optionally, after executing step 404, the following step (31) can also be executed.

[0152] (31) The electronic device uploads the SOC deviation of the battery to the cloud server.

[0153] In the embodiments of the present application, the SOC deviation calculated by the electronic device can be uploaded to the cloud server for analyzing the battery consistency in real time, serving as the data basis for subsequent development, such as studying the change trend of the cell consistency and judging whether there are other problems with the battery, such as whether the consistency of the battery changes too fast. Other features (such as the minimum section ratio and the maximum section ratio of the battery cells during this period) can also be uploaded simultaneously as criteria to increase the credibility of the battery consistency.

[0154] The electronic device can be a cloud server for calculating the battery SOC deviation. The cloud server for calculating the battery SOC deviation can upload the calculated battery SOC deviation to the cloud server for analyzing the battery consistency. The cloud server for calculating the battery SOC deviation and the cloud server for analyzing the battery consistency can be different servers.

[0155] Please refer to Figure 7 , Figure 7 which is a schematic flow diagram of a method for determining the consistency of a battery provided by an embodiment of the present application. As Figure 7 shown, the method for determining the consistency of the battery includes the following steps.

[0156] 701. The cloud server filters out the battery status sequence information of the target vehicle within the target time.

[0157] Among them, there can be multiple pieces of battery status sequence information, which can correspond to the above-mentioned original data frames.

[0158] The battery status sequence information can include: vehicle status data, the highest and lowest cell voltages, current, temperature, battery SOC value, the highest and lowest cell numbers, etc. The vehicle can mark the sampling time for these data and upload them to the cloud server for subsequent processing.

[0159] 702. The cloud server preprocesses the battery status sequence information by sorting by time, removing null values, removing duplicate data, removing invalid values, removing outliers, and removing high-current working conditions.

[0160] Among them, the data uploaded by the vehicle can be preprocessed every 24 hours, including sorting by time, removing null values, removing duplicate data, removing invalid values, removing sampling outliers, deleting data for working conditions that do not apply to the algorithm, etc.

[0161] The data after the preprocessing is input into the algorithm. In the algorithm, mainly the battery SOC value, the highest cell voltage V max , the lowest cell voltage V min , the highest cell number Nmax, the lowest cell number Nmin and other values are filtered and analyzed.

[0162] 703. The cloud server obtains the voltage difference according to the difference between the highest cell voltage and the lowest cell voltage, divides the data according to the working conditions to obtain different charging section data and discharging section data, obtains the pressure difference lower envelope for the discharging section data, and performs polynomial regression and Butterworth filtering on the discharging section data.

[0163] Among them, the difference can be made between the highest cell voltage V max and the lowest cell voltage V min , V diff =V max -V min。The obtained V diff represents the voltage difference between the cell with the highest electrical state and the cell with the lowest electrical state.

[0164] Due to the unstable voltage in the discharge section, the sampled cell voltage will fluctuate. It is necessary to filter the voltage difference V diff of the cells to filter out small sampling errors and different voltage transient responses caused by large currents. First, obtain the lower envelope of the voltage difference, perform polynomial regression on the lower envelope value and interpolate to obtain V env (i.e., the above-mentioned fitted voltage difference value), and then use Butterworth low-pass filtering to filter the noise on V env to obtain a smooth voltage difference value V env . At this time, the voltage difference when the battery SOC value is between 50% and 90% can be used to judge the consistency (the voltage difference above 90% SOC is very high, and the SOC below 50% will be affected by low inflection points, so the data in the SOC interval of 50% to 90% is selected).

[0165] 704. The cloud server groups the charging section data and the discharge section data according to SOC to find the minimum value, calculates the SOC interval where the continuous voltage difference is greater than the set threshold, obtains the SOC deviation of the battery, and counts the highest cell number and the lowest cell number in the data corresponding to this SOC interval.

[0166] In the embodiment of the present application, the data of the entire battery pack with SOC between 50% and 90% is grouped once with an integer SOC (for example, SOC can be divided into: 50%, 51%, 52%,..., 90%, a total of 41 groups) as the exponent. The grouping function is to find the minimum value, which changes the original variable of time (data frame number) to SOC as the variable, and obtains the minimum voltage difference corresponding to each integer SOC value.

[0167] Among them, the set threshold can be determined by Figure 1 . It can be seen from Figure 1 that when the lithium iron phosphate battery is in two different large platforms, the voltage difference is above 25 mV. Therefore, the voltage difference threshold is designed to be 25 mV. If the cell with the highest electrical state and the cell with the lowest electrical state are both in the same platform at the same time, the V max -V min obtained V diff will be very small. As the vehicle charges and discharges or charges, the cell with the highest electrical state and the cell with the lowest electrical state will successively pass through the inflection point 2 between the large platform 1 and the large platform 2. Record the SOC1 when the highest voltage cell passes through the inflection point and the SOC2 when the lowest voltage cell passes through the inflection point. |SOC2 - SOC1| is the consistency deviation of the cells.

[0168] 705. The cloud server uploads the SOC deviation of the battery, the lowest cell ratio, and the highest cell ratio of the cells to the cloud.

[0169] Among them, the calculated SOC deviation of the battery can be uploaded to the cloud server in real time, serving as the data basis for subsequent development. For example, it can be used to study the change trend of the cell consistency and determine whether there are other problems with the cells, such as whether the consistency changes too quickly. At the same time, other features (such as the lowest cell ratio and the highest cell ratio during this period) are also uploaded as criteria to increase the credibility of the consistency.

[0170] The lowest cell ratio of the cell refers to the proportion of each cell that is the cell with the lowest voltage in the data corresponding to this SOC interval. The highest cell ratio of the cell refers to the proportion of each cell that is the cell with the highest voltage in the data corresponding to this SOC interval.

[0171] The technical problem that can be solved by the embodiments of the present application is that the method for calculating the state of charge (SOC) deviation of battery cells relies too much on specific charging section data. When specific data is missing or only exists recently, it will cause the traditional algorithm to fail or unable to obtain the real-time SOC deviation of the cells. When the data quality is poor, such as the synchronization rate is insufficient, the traditional solution uses the data in the AC charging stage and cannot use the data in the discharge stage.

[0172] The algorithm of the embodiments of the present application is applicable to different vehicle operating conditions. This algorithm not only uses the data including the AC charging section to calculate the SOC deviation of the battery, but also can use the data including the discharge section to calculate the SOC deviation of the battery, and calculate the SOC deviation of the battery more timely.

[0173] The embodiments of the present application can discriminate the SOC deviation of the battery, and judge whether there are other consistency problems (such as abnormal internal resistance and leakage, etc.) based on the SOC deviation of the battery. The embodiments of the present application can calculate the SOC deviation of the vehicle's battery in the cloud server, continuously track the battery consistency state, and provide a basis for the trend algorithm.

[0174] The above introduces the solution of the embodiments of the present application from the perspective of the execution process on the method side. It can be understood that in order for the electronic device to implement the above functions, it includes the corresponding hardware structure and / or software module for executing each function. Those skilled in the art should easily realize that, combining the units and algorithm steps of each example described in the embodiments provided in this article, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed in the way of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0175] Embodiments of the present application can divide functional units of an electronic device according to the above method examples. For example, each functional unit can be divided corresponding to each function, or two or more functions can be integrated into one processing unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit. It should be noted that the division of units in the embodiments of the present application is illustrative, merely a logical function division, and there can be other division methods in actual implementation.

[0176] Please refer to Figure 8 , Figure 8 which is a schematic structural diagram of a battery consistency determination device provided by an embodiment of the present application. The battery includes at least two battery cells, and the battery consistency determination device 800 may include a determination unit 801, where:

[0177] The determination unit 801 is configured to determine the voltage difference corresponding to each frame of data, and the voltage difference is the difference between the highest battery cell voltage and the lowest battery cell voltage in each frame of data;

[0178] The determination unit 801 is further configured to determine a battery SOC interval based on the correspondence between the voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, and the voltage difference corresponding to the battery SOC interval is greater than a set threshold;

[0179] The determination unit 801 is further configured to determine the difference between the upper limit value and the lower limit value of the battery SOC interval to obtain the SOC deviation of the battery, and the SOC deviation of the battery is used to measure the consistency of the battery.

[0180] Optionally, each frame of data is any preprocessed frame data of the battery within a set time period.

[0181] Optionally, the set time period includes at least one of a discharge period, an AC charging period, and a DC charging period.

[0182] Optionally, the preprocessing includes at least one of sorting by time, removing null values, removing duplicate data, removing invalid values, removing sampling outliers, and removing data that does not conform to the algorithm working conditions.

[0183] Optionally, the battery consistency determination device 800 may further include a filtering unit 802;

[0184] The filtering unit 802 is configured to perform filtering processing on the voltage difference corresponding to each frame of data to obtain the processed voltage difference corresponding to each frame of data;

[0185] The determining unit 801 determines a battery SOC interval based on the correspondence between the voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, where the voltage difference corresponding to the battery SOC interval is greater than a set threshold, including: determining a battery SOC interval based on the correspondence between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, where the processed voltage difference corresponding to the battery SOC interval is greater than the set threshold.

[0186] Optionally, the filtering unit 802 performs filtering processing on the voltage difference corresponding to each frame of data to obtain the processed voltage difference corresponding to each frame of data, including: determining a set of credible voltage differences among the voltage differences corresponding to each frame of data within the set time period; performing polynomial fitting based on the set of credible voltage differences to obtain the fitted voltage difference corresponding to each frame of data within the set time period; performing filtering processing on the fitted voltage difference corresponding to each frame of data within the set time period to obtain the processed voltage difference corresponding to each frame of data.

[0187] Optionally, the filtering unit 802 determines a set of credible voltage differences among the voltage differences corresponding to each frame of data within the set time period, including: obtaining a first curve of the change of the voltage difference corresponding to each frame of data within the set time period based on the correspondence between the voltage difference corresponding to each frame of data and the sampling time point corresponding to each frame of data; determining a first curve segment in the first curve where the voltage difference is greater than a first threshold, determining a lower envelope region in the first curve segment, and determining the smallest N voltage differences in the lower envelope region as the set of credible voltage differences among the voltage differences corresponding to each frame of data within the set time period, where N is an integer greater than or equal to 2.

[0188] Optionally, the determining unit 801 determines a battery SOC interval based on the correspondence between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, including: obtaining a second curve of the change of the processed voltage difference with the battery SOC value within the set time period based on the correspondence between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data; determining a second curve segment in the second curve where the processed voltage difference is greater than the set threshold, and determining the battery SOC interval corresponding to the second curve segment.

[0189] Optionally, the determining unit 801 obtains a second curve of the processed voltage difference varying with the battery SOC value within the set period based on the correspondence between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, including: determining, based on the correspondence between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, the minimum value among at least two processed voltage differences corresponding to the same battery SOC value as the processed voltage difference corresponding to the same battery SOC value; and obtaining, based on the processed voltage differences corresponding to each different battery SOC value, a second curve of the processed voltage difference varying with the battery SOC value within the set period.

[0190] Optionally, the battery consistency determination device 800 may further include an uploading unit 803;

[0191] The uploading unit 803 is configured to upload the SOC deviation of the battery to a cloud server.

[0192] Optionally, the set threshold is greater than the difference between the upper limit and the lower limit of the voltage fluctuation range of the first plateau region, and the set threshold is greater than the difference between the upper limit and the lower limit of the voltage fluctuation range of the second plateau region, and the set threshold is less than the absolute value of the difference between the upper limit of the voltage fluctuation range of the first plateau region and the lower limit of the voltage fluctuation range of the second plateau region. The first plateau region and the second plateau region are two adjacent plateau regions in the SOC-OCV curve of the battery.

[0193] Optionally, the SOC-OCV curve of the battery includes a small plateau region, a first large plateau region, and a second large plateau region. The SOC value of the first large plateau region is greater than the SOC value of the small plateau region and less than the SOC value of the second large plateau region; the first plateau region is one of the first large plateau region and the second large plateau region, and the second plateau region is the other of the first large plateau region and the second large plateau region.

[0194] Wherein, the determining unit 801 and the filtering unit 802 in the embodiments of the present application may be processors in an electronic device. The uploading unit 803 may be a communication module in an electronic device.

[0195] In the embodiments of the present application, based on the correspondence between the voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, a battery SOC interval is determined. The difference between the upper limit value and the lower limit value of the battery SOC interval is determined as the SOC deviation of the battery. During the process of determining the SOC deviation of the battery, only the battery SOC value is required, and it is not necessary to calculate the SOC value of each battery cell, which can reduce the calculation amount for determining the SOC deviation, thereby quickly determining the consistency of the battery.

[0196] Please refer to Figure 9 , Figure 9 which is a schematic structural diagram of an electronic device provided by an embodiment of the present application. As Figure 9 shown, the electronic device 900 includes a processor 901 and a memory 902. The processor 901 and the memory 902 can be interconnected through a communication bus 903. The communication bus 903 can be a peripheral component interconnect (PCI) bus, an extended industry standard architecture (EISA) bus, a controller area network (CAN) bus, or the like. The communication bus 903 can be divided into an address bus, a data bus, a control bus, etc. For the sake of simplicity of representation, Figure 9 only a thick line is shown in Figures 2 to 7 but it does not mean that there is only one bus or one type of bus. The memory 902 is used to store a computer program, and the computer program includes program instructions. The processor 901 is configured to call the program instructions, and the above program includes steps for executing

[0197] part or all of the methods included in

[0198] The memory 902 can be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or can also be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM), or other optical disc storage, optical disc storage (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media, or other magnetic storage devices, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory can exist independently and be connected to the processor through a bus. The memory can also be integrated with the processor.

[0199] The electronic device 900 can also include a communication module 904, through which the SOC deviation of the battery can be uploaded to the cloud server. The original data frame uploaded by the vehicle can also be received through the communication module 904.

[0200] In the embodiments of the present application, based on the correspondence between the voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, the battery SOC interval is determined, and the difference between the upper limit value and the lower limit value of the battery SOC interval is determined as the SOC deviation of the battery. Only the battery SOC value is required in the process of determining the SOC deviation of the battery, and it is not necessary to calculate the SOC value of each battery cell, which can reduce the calculation amount of determining the SOC deviation, thereby quickly determining the consistency of the battery.

[0201] Please refer to Figure 10 , Figure 10 which is a schematic structural diagram of a server provided by the embodiments of the present application. As Figure 10 shown, the server 1000 includes a first communication module 1001 and a processing module 1002. The first communication module 1001 is used to communicate with the power device where the battery is located to receive each frame of data, and the processing module 1002 is used to execute some or all of the steps of any one of the battery consistency determination methods described in the above method embodiments.

[0202] The processing module 1002 may be a general - purpose central processing unit (CPU), a microprocessor, an application - specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the above - mentioned battery consistency determination method.

[0203] Optionally, when the SOC deviation is greater than a preset warning threshold, the processing module 1002 is further configured to send a warning signal to the power device through the first communication module 1001.

[0204] Please refer to Figure 11 , Figure 11 which is a schematic structural diagram of a power device provided by an embodiment of the present application. As Figure 11 shown, the power device 1100 includes a battery 1101 and a processing component 1102. The processing component 1102 is configured to execute some or all of the steps of any one of the battery consistency determination methods described in the above - mentioned method embodiments according to each frame of data of the battery 1101.

[0205] The processing component 1102 may be a general - purpose central processing unit (CPU), a microprocessor, an application - specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the above - mentioned battery consistency determination method.

[0206] Optionally, the power device includes a warning component 1103. The processing component 1102 is further configured to trigger the warning component 1103 to send a warning message and / or send a warning prompt message to a third - party device when the SOC deviation is greater than a preset warning threshold.

[0207] An embodiment of the present application further provides a computer - readable storage medium. The computer - readable storage medium stores a computer program for electronic data exchange, and the computer program enables a computer to execute some or all of the steps of any one of the battery consistency determination methods described in the above - mentioned method embodiments.

[0208] It should be noted that, for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that this application is not limited by the described action sequence, because according to this application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0209] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0210] In several embodiments provided by this application, it should be understood that the disclosed device can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed mutual coupling, direct coupling or communication connection can be through some interfaces. The indirect coupling or communication connection of the device or unit can be in an electrical or other form.

[0211] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0212] In addition, in each embodiment of the application, the various functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above integrated units can be implemented in the form of hardware or in the form of software program modules.

[0213] When the integrated unit is implemented in the form of a software program module and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of this application. The aforementioned memory includes various media that can store program codes, such as USB flash drives, read-only memories (ROM), random access memories (RAM), mobile hard disks, magnetic disks, or optical discs.

[0214] Those of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing relevant hardware through a program. This program can be stored in a computer-readable memory, and the memory can include: flash drives, read-only memories, random access memories, magnetic disks, or optical discs, etc.

[0215] The above has introduced the embodiments of this application in detail. Specific examples are used in this article to elaborate on the principle and implementation manner of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application; at the same time, for those of ordinary skill in the art, according to the idea of this application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to this application.

Claims

1. A method for determining the consistency of a battery, the battery comprising at least two battery cells, characterized in that, The method includes: Determining a voltage difference corresponding to each frame of data, where the voltage difference is the difference between the highest cell voltage and the lowest cell voltage in each frame of data; Based on the correspondence between the voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, determining a battery SOC interval, where the voltage difference corresponding to the battery SOC interval is greater than a set threshold; Determining the difference between the upper limit value and the lower limit value of the battery SOC interval as the SOC deviation of the battery, where the SOC deviation of the battery is used to measure the consistency of the battery.

2. The method according to claim 1, wherein Each frame of data is any preprocessed frame of data of the battery during a set period.

3. The method according to claim 2, characterized in that, The set period includes at least one of a discharge period, an AC charging period, and a DC charging period.

4. The method according to claim 2, wherein The preprocessing includes at least one of sorting by time, removing null values, removing duplicate data, removing invalid values, removing sampling outliers, and removing data that does not conform to the algorithm working condition.

5. The method according to any one of claims 2 to 4, characterized in that, After determining the voltage difference corresponding to each frame of data, the method further includes: Performing a filtering process on the voltage difference corresponding to each frame of data to obtain a processed voltage difference corresponding to each frame of data; The determining the battery SOC interval based on the correspondence between the voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, where the voltage difference corresponding to the battery SOC interval is greater than a set threshold, includes: Based on the correspondence between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, determining a battery SOC interval, where the processed voltage difference corresponding to the battery SOC interval is greater than a set threshold.

6. The method according to claim 5, wherein The performing a filtering process on the voltage difference corresponding to each frame of data to obtain a processed voltage difference corresponding to each frame of data includes: Determining a set of credible voltage differences among the voltage differences corresponding to each frame of data within the set period; Performing polynomial fitting based on the set of credible voltage differences to obtain a fitted voltage difference corresponding to each frame of data within the set period; Performing a filtering process on the fitted voltage difference corresponding to each frame of data within the set period to obtain a processed voltage difference corresponding to each frame of data.

7. The method according to claim 6, wherein The determining the set of credible voltage differences among the voltage differences corresponding to each frame of data within the set period includes: Based on the correspondence between the voltage difference corresponding to each frame of data and the sampling time point corresponding to each frame of data, obtaining a first curve of the change of the voltage difference corresponding to each frame of data with time within the set period; Determining a first curve segment in the first curve where the voltage difference is greater than a first threshold, determining a lower envelope region in the first curve segment, and determining the smallest N voltage differences in the lower envelope region as the set of credible voltage differences among the voltage differences corresponding to each frame of data within the set period, where N is an integer greater than or equal to 2.

8. The method according to claim 5, wherein The determining the battery SOC interval based on the correspondence between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data includes: Based on the corresponding relationship between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, a second curve showing the change of the processed voltage difference with the battery SOC value within the set time period is obtained; Determine a second curve segment in the second curve where the processed voltage difference is greater than a set threshold, and determine the battery SOC interval corresponding to the second curve segment.

9. The method according to claim 8, wherein The obtaining of the second curve showing the change of the processed voltage difference with the battery SOC value within the set time period based on the corresponding relationship between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data includes: Based on the corresponding relationship between the processed voltage difference corresponding to each frame of data and the battery SOC value in each frame of data, determine the minimum value among at least two processed voltage differences corresponding to the same battery SOC value as the processed voltage difference corresponding to the same battery SOC value; Based on the processed voltage differences corresponding to each different battery SOC value, obtain a second curve showing the change of the processed voltage difference with the battery SOC value within the set time period.

10. The method according to any one of claims 1 to 9, characterized in that, After obtaining the SOC deviation of the battery, the method further includes: Upload the SOC deviation of the battery to the cloud server.

11. The method according to any one of claims 1 to 10, characterized in that The set threshold is greater than the difference between the upper limit and the lower limit of the voltage fluctuation range of the first platform area, and the set threshold is greater than the difference between the upper limit and the lower limit of the voltage fluctuation range of the second platform area, and the set threshold is less than the absolute value of the difference between the upper limit of the voltage fluctuation range of the first platform area and the lower limit of the voltage fluctuation range of the second platform area. The first platform area and the second platform area are two adjacent platform areas in the SOC-OCV curve of the battery.

12. The method according to claim 11, wherein The SOC-OCV curve of the battery includes a small platform area, a first large platform area, and a second large platform area. The SOC value of the first large platform area is greater than the SOC value of the small platform area and less than the SOC value of the second large platform area; the first platform area is one of the first large platform area and the second large platform area, and the second platform area is the other of the first large platform area and the second large platform area.

13. A server, characterized in that, The server includes a first communication module and a processing module. The first communication module is used to communicate with the power equipment where the battery is located to receive each frame of data, and the processing module is used to execute the method according to any one of claims 1 to 12.

14. The server according to claim 13, wherein When the SOC deviation is greater than a preset warning threshold, the processing module is further used to send a warning signal to the power equipment through the first communication module.

15. An electrical energy device, characterized in that, The power equipment includes a battery and a second communication module. The second communication module is used to send each frame of data of the battery to the server so that the server executes the method according to any one of claims 1 to 12 based on the each frame of data.

16. An electrical energy device, characterized in that, The power equipment includes a battery and a processing component. The processing component is used to execute the method according to any one of claims 1 to 12 based on each frame of data of the battery.

17. The device according to claim 16, characterized in that, The power equipment includes a warning component, and the processing component is further configured to trigger the warning component to send a warning message and / or send a warning prompt message to a third-party device when the SOC deviation is greater than a preset warning threshold.

18. An electronic device, characterized in that, It includes a processor and a memory. The memory is used to store a computer program, and the computer program includes program instructions. The processor is configured to call the program instructions to execute the method according to any one of claims 1 to 12.

19. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, and the computer program includes program instructions. When the program instructions are executed by a processor, the processor is caused to execute the method according to any one of claims 1 to 12.

20. A computer program product, characterized in that, The computer program product includes a computer program, and the computer program is operable to cause a computer to execute the method according to any one of claims 1 to 12.

21. A processor, characterized in that, The processor is configured to call program instructions to execute the method according to any one of claims 1 to 12.

Images