Battery state of charge correction method and apparatus

Abstract

The application discloses a battery state of charge correction method and device, the method comprises the following steps: acquiring first voltage information of each single battery cell in a battery pack, first temperature information of the battery pack and first current information of the battery pack; in the case that the first voltage information is in a first state and the first voltage information is in a correctable range, querying a corresponding relationship table constructed in advance based on the first voltage information, the first temperature information and the first current information to obtain first state of charge information of each single battery cell corresponding to the first voltage information, the first temperature information and the first current information; and correcting current state of charge information of each single battery cell based on the first state of charge information of each single battery cell to obtain target state of charge information of each single battery cell. The correction accuracy of the state of charge of the battery is improved.

Description

Technical Field

[0001] This application relates to the field of automotive electronics technology, specifically to a method and apparatus for correcting the state of charge of a battery. Background Technology

[0002] Existing low-voltage power supply state of charge (SOC) static correction schemes typically use open circuit voltage (OCV) for correction. Specifically, after the battery has been in a dormant state for a certain period of time, the open circuit voltage at the cell end is collected, and then the current SOC value is corrected by looking up the cell end voltage using a static SOC-OCV table provided by the battery manufacturer. However, the SOC value corrected by this scheme is not accurate. Summary of the Invention

[0003] The purpose of this application is to provide a battery state of charge correction method and apparatus to improve the correction accuracy of the battery's SOC value.

[0004] The technical solution of this application is as follows:

[0005] Firstly, a method for correcting the state of charge of a battery is provided, the method comprising:

[0006] Obtain the first voltage information of each individual cell in the battery pack, the first temperature information of the battery pack, and the first current information of the battery pack at the current moment.

[0007] If it is determined that the first voltage information is in a first state and is within a correctable range, a lookup is performed in a pre-built correspondence table based on the first voltage information, the first temperature information, and the first current information to obtain the first state of charge information of each individual cell corresponding to the first voltage information, the first temperature information, and the first current information. The correspondence table contains the correspondence between the voltage information of the individual cell, the temperature information of the battery pack, the current information of the battery pack, and the state of charge information.

[0008] Based on the first state of charge information of each individual cell, the current state of charge information of each individual cell is corrected to obtain the target state of charge information of each individual cell.

[0009] Secondly, a battery state-of-charge correction device is provided, the device comprising:

[0010] The acquisition module is used to acquire the first voltage information of each individual cell in the battery pack, the first temperature information of the battery pack, and the first current information of the battery pack at the current moment.

[0011] The first determining module is configured to, when determining that the first voltage information is in a first state and the first voltage information is within a correctable range, query a pre-built correspondence table based on the first voltage information, the first temperature information, and the first current information to obtain the first state of charge information of each individual cell corresponding to the first voltage information, the first temperature information, and the first current information. The correspondence table contains the correspondence between the voltage information of the individual cell, the temperature information of the battery pack, the current information of the battery pack, and the state of charge information.

[0012] The second determining module is used to correct the current state of charge information of each individual cell based on the first state of charge information of each individual cell, so as to obtain the target state of charge information of each individual cell.

[0013] Thirdly, embodiments of this application provide an electronic device, which includes a processor, a memory, and a program or instructions stored in the memory and executable on the processor. When the program or instructions are executed by the processor, they implement the steps of any of the battery state-of-charge correction methods described in the embodiments of this application.

[0014] Fourthly, embodiments of this application provide a readable storage medium storing a program or instructions, which, when executed by a processor, implement the steps of any of the battery state-of-charge correction methods described in embodiments of this application.

[0015] Fifthly, embodiments of this application provide a computer program product, wherein the instructions in the computer program product, when executed by the processor of an electronic device, enable the electronic device to perform the steps of any of the battery state-of-charge correction methods described in embodiments of this application.

[0016] The technical solutions provided by the embodiments of this application bring at least the following beneficial effects:

[0017] In the embodiments of this application, by acquiring the first voltage information, the first temperature information, and the first current information of each individual cell in the battery pack at the current moment, and determining that the first voltage information is in a first state and within a correctable range, a query is performed in a pre-constructed correspondence table based on the first voltage information, the first temperature information, and the first current information to obtain the first state of charge information of each individual cell corresponding to the first voltage information, the first temperature information, and the first current information. Based on the first state of charge information of each individual cell, the current state of charge information of each individual cell is corrected to obtain the target state of charge information of each individual cell. Since the correspondence table contains the correspondence between the voltage information of the individual cell, the temperature information of the battery pack, the current information of the battery pack, and the state of charge information, compared with the correspondence table in the prior art which only has the correspondence between state of charge information and voltage information, the correspondence provided in the embodiments of this application contains both voltage information and the temperature and current information of the battery pack. This avoids the influence of small current discharge and temperature on the correction of state of charge information when the battery pack is stationary, thus improving the correction accuracy of the state of charge information of the battery pack.

[0018] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application, and do not constitute an undue limitation of this application.

[0020] Figure 1 This is a schematic flowchart of a battery state-of-charge correction method provided in the first aspect embodiment of this application.

[0021] Figure 2 This is a schematic diagram of the voltage-time curve of a lithium iron phosphate battery under full charge state according to the first aspect embodiment of this application.

[0022] Figure 3 This is a schematic diagram of the structure of a battery state of charge correction device provided in the second aspect embodiment of this application.

[0023] Figure 4 This is a schematic diagram of the structure of an electronic device provided in the third aspect of this application. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0025] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples consistent with some aspects of this application as detailed in the appended claims.

[0026] Before introducing the embodiments of this application, let's first introduce the technical terms involved in the embodiments of this application:

[0027] State of charge, also known as remaining capacity, represents the ratio of a battery's remaining capacity after a period of use or long-term storage to its capacity in a fully charged state. It is usually expressed as a percentage. Its value ranges from 0 to 1.

[0028] First, let's introduce the background technology of the embodiments of this application:

[0029] Existing low-voltage power supply SOC (State of Charge) static correction schemes typically use open-circuit voltage (OCV) for correction. Specifically, the battery pack is allowed to enter a dormant state for a certain period, and the open-circuit voltage at the cell end is collected. Then, a static SOC-OCV table provided by the battery manufacturer is used to look up the cell-end voltage to correct the current SOC value. Specifically, the static SOC-OCV table provided by the battery manufacturer records the voltage at different SOC intervals during charging and discharging, forming a one-dimensional SOC-OCV curve. However, in actual vehicle operation, there are generally low-current discharge conditions. Coupled with the periodic wake-up power consumption of other electronic control units (ECUs) in the vehicle, the battery pack's discharge current will also fluctuate periodically, resulting in periodic voltage fluctuations. Using a static SOC-OCV table for correction will lead to inaccurate correction. Secondly, while OCV is generally considered to be independent of temperature, under conditions of small current discharge, the ohmic resistance voltage division and polarization voltage division caused by different temperatures are also different, so temperature does actually affect the correction accuracy. Finally, current OCV correction generally involves a 1-hour or 2-hour sleep period. If there is a pulse discharge current before waking up, it will lower the individual cell voltage, resulting in inaccurate correction when power-on.

[0030] In summary, existing technologies suffer from inaccurate state-of-charge (SOC) correction of battery packs. To address this issue, this application provides a battery SOC correction method and apparatus. By acquiring the first voltage information of each individual cell in the battery pack, the first temperature information of the battery pack, and the first current information of the battery pack at the current moment, and determining that the first voltage information is in a first state and within a correctable range, a lookup is performed in a pre-built correspondence table based on the first voltage information, first temperature information, and first current information to obtain the first SOC information of each individual cell corresponding to the first voltage information, first temperature information, and first current information. The first state of charge information of each individual cell is used to correct the current state of charge information of each individual cell to obtain the target state of charge information of each individual cell. Since the correspondence table contains the correspondence between the voltage information of the individual cell, the temperature information of the battery pack, the current information of the battery pack, and the state of charge information, compared with the correspondence table in the prior art which only has the correspondence between state of charge information and voltage information, the correspondence provided in this application embodiment contains both voltage information and the temperature and current information of the battery pack. This can avoid the influence of small current discharge and temperature on the correction of state of charge information when the battery pack is stationary, thus improving the correction accuracy of the state of charge information of the battery pack.

[0031] The battery state of charge correction method provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0032] It should be noted that the battery packs mentioned in the embodiments of this application are all lithium iron phosphate batteries.

[0033] Figure 1 This is a flowchart illustrating a battery state-of-charge correction method provided in an embodiment of this application. The execution entity of this battery state-of-charge correction method can be a server. Figure 1 As shown, the battery state of charge correction method provided in this application embodiment may include steps 110-130.

[0034] Step 110: Obtain the first voltage information of each individual cell in the battery pack, the first temperature information of the battery pack, and the first current information of the battery pack at the current moment.

[0035] The first voltage information can be the voltage information of each individual cell in the battery pack at the current moment.

[0036] The first temperature information can be the temperature of the battery pack at the current moment.

[0037] The first current information can be the current information of the battery pack at the current moment.

[0038] It should be noted that the individual cells in the battery pack are connected in series, so the current information of the entire battery pack is equivalent to the current information of each individual cell. Therefore, the first current information here is also equivalent to the current information of each individual cell in the battery pack.

[0039] In some embodiments of this application, when collecting the temperature information of the battery pack, the temperature of each individual cell in the battery pack is set to be the same and is equivalent to the temperature information of the battery pack. Therefore, the first temperature information here is also equivalent to the temperature information of each individual cell in the battery pack.

[0040] In some embodiments of this application, the first voltage information of each individual cell in the battery pack, the first temperature information of the battery pack, and the first current information of the battery pack can be obtained in real time based on sensors. Alternatively, the first voltage information of each individual cell in the battery pack, the first temperature information of the battery pack, and the first current information of the battery pack at each time can be stored in a memory, and then the first voltage information of each individual cell in the battery pack, the first temperature information of the battery pack, and the first current information of the battery pack at each time can be obtained from the memory. No limitation is made here.

[0041] Step 120: If it is determined that the first voltage information is in the first state and the first voltage information is within the correctable range, based on the first voltage information, the first temperature information and the first current information, a query is performed in the pre-constructed correspondence table to obtain the first state of charge information of each individual cell corresponding to the first voltage information, the first temperature information and the first current information.

[0042] The first state can be a pre-set state in which the first voltage information should be when the state of charge information of the battery pack is corrected. Specifically, the first voltage information should be in a stable state, that is, at the current moment, during the process of correcting the state of charge information based on the first voltage information, the first voltage information is stable and unchanged.

[0043] The correctable range can be the plateau region of the OCV curve where the first voltage information is located. See also Figure 2 , Figure 2 This is a voltage-time curve of a lithium iron phosphate battery under full charge. Figure 2 In the graph, the vertical axis represents voltage and the horizontal axis represents time. According to this curve, there is a plateau region in the OCV curve, meaning there is a relatively large SOC operating range where the change in static terminal voltage is not significant. Figure 2 The curve between points A and B shows no significant voltage change. Because there is a certain error in the analog voltage acquisition of each individual cell in the battery pack, typically 3-5mV, this error introduces a large SOC correction error in the voltage plateau region. Therefore, the first voltage information should only be corrected in the non-plateau region to ensure a smaller correction error. Thus, the correctable range here is determined by the first voltage information within... Figure 2 The non-plateau region of the OCV curve in the image can be corrected within a certain range. Figure 2 The other curved regions besides curve AB.

[0044] The correspondence table can be a table showing the correspondence between the voltage information of a single battery cell, the temperature information of the battery pack, the current information of the battery pack, and the state of charge information.

[0045] The first state of charge information can be obtained by querying a corresponding table based on the first voltage information, the first temperature information, and the first current information.

[0046] In some embodiments of this application, a binary search method may be used for index lookup when performing a table lookup.

[0047] In some embodiments of this application, in order to accurately determine whether the first voltage information is in the first state, after step 110, the battery state of charge correction method mentioned above may further include:

[0048] Obtain the second voltage information of each individual cell in the battery pack from the last collected data at the current moment.

[0049] Calculate the first difference between the first voltage information and the second voltage information.

[0050] Get the absolute value of the first difference.

[0051] If the ratio of the absolute value to the first duration is less than or equal to the first threshold, the state information of the first voltage information is determined to be the first state.

[0052] The "last time" for the current moment can be the time before the last data collection. It can be set to collect and correct the battery pack's state of charge information every preset time interval, for example, every 3 hours. If the current time is 10:00 AM on April 27, 2023, then the "last time" for the current moment would be 7:00 AM on April 27, 2023.

[0053] The second voltage information can be the voltage information of each individual cell in the battery pack that was last collected at the current moment.

[0054] The first difference can be the difference between the first voltage information and the second voltage information.

[0055] The first duration can be the duration between the current moment and the previous moment.

[0056] The first threshold can be a threshold value that is the ratio of the absolute value of the first time to the first duration. This threshold can be set by the user according to their needs, and there is no limitation here.

[0057] In some embodiments of this application, by obtaining the second voltage information of each individual cell in the battery pack collected at the current moment, then calculating the first voltage information and the first voltage information, obtaining the absolute value of the first difference, and then based on the absolute value and the first duration, it is possible to accurately determine whether the state information of the first voltage information is in the first state.

[0058] In some embodiments of this application, based on the Thevenin equivalent circuit, the polarization voltage of the battery is equivalent to a parallel connection of a capacitor and a resistor. When the discharge current and temperature stabilize, the polarization internal resistance tends to stabilize, and the polarization voltage also tends to stabilize. At this time, it is considered that the battery terminal voltage is consistent with the test condition corresponding to the battery three-dimensional OCV correction correspondence. Thus, it can be determined whether the polarization voltage has reached a stable state, i.e., whether the first voltage information is in the first state, based on the following formula (1):

[0059]

[0060] Wherein, V2 is the voltage value of the single cell detected after this wake-up, i.e., the first voltage information; V1 is the voltage value of the single cell recorded during the last timed wake-up, i.e., the second voltage information; T is the time interval between the two wake-ups, i.e., the first duration; and Q is the threshold for judging that the polarization voltage has reached a stable state, i.e., the first threshold. The Battery Management System (BMS) needs to record the voltage value of the single cell during each cycle wake-up. After the interval T, it subtracts the recorded voltage value from the collected single cell voltage value and divides it by time T. If the rate of change is greater than Q, it is determined that the polarization voltage has not stabilized, and the current voltage value can be stored in the Electrically Erasable Programmable Read-Only Memory (EEPROM), and the BMS enters sleep mode. If the rate of change is less than Q, the polarization is considered stable, and the next step of judgment can be performed.

[0061] In some embodiments of this application, in order to accurately determine that the first voltage information is within the correctable range, after step 110, the battery state of charge correction method described above may further include:

[0062] Obtain the pre-set standard error of each individual cell in the battery pack.

[0063] Calculate the first error voltage information and the second error voltage information under the standard error of the first voltage information.

[0064] Based on the first temperature information and the first current information, the corresponding relationship table is consulted to obtain the first error state of charge information under the first error voltage information and the second error state of charge information under the second error voltage information.

[0065] Based on the first error state of charge information and the second error state of charge information, determine whether the first voltage information is within the correctable range.

[0066] The standard error can be a pre-set allowable error range for the voltage of each individual cell in the battery pack, for example, 3 to 5 mV.

[0067] The first error voltage information can be the voltage information of the first voltage information under the standard error.

[0068] The second error voltage information can be another voltage information of the first voltage information under the standard error.

[0069] In one example, if d is a preset standard error and volt is the first voltage information, then volt+d and volt-d can be the first error voltage information and the second error voltage information, respectively.

[0070] The first error state of charge information can be obtained by querying a corresponding relationship table based on the first error voltage information, the first temperature information, and the first current information.

[0071] The second error state of charge information can be obtained by querying the corresponding relationship table based on the second error voltage information, the first temperature information, and the first current information.

[0072] In the embodiments of this application, by calculating the first error voltage information and the second error voltage information under the standard error of the first voltage information, and then by querying the corresponding relationship table according to the first temperature information and the first current information, the first error state of charge information under the first error voltage information and the second error state of charge information under the second error voltage information are obtained respectively. Then, based on the first error state of charge information and the second error state of charge information, it can be accurately determined whether the first voltage information is within the correctable range.

[0073] In some embodiments of this application, in order to accurately determine whether the first voltage information is within the correctable range, the step of determining whether the first voltage information is within the correctable range based on the first error state of charge information and the second error state of charge information may specifically include:

[0074] Calculate the second difference between the first error state of charge information and the second error state of charge information.

[0075] If the second difference is greater than zero and the second difference is less than or equal to the second threshold, the first voltage information is determined to be within the correctable range.

[0076] The second difference can be the difference between the first error state of charge information and the second error state of charge information.

[0077] The second threshold can be a pre-set threshold for the second difference, which can be set by the user according to their needs; there are no restrictions here.

[0078] In some embodiments of this application, the first voltage information can be determined to be within the correctable range when the first voltage information specifically satisfies the following formula (2):

[0079] 0 < SOC volt+d -SOC volt-d ≤Tol(2)

[0080] Where volt represents the voltage of a single cell in the battery pack, i.e., the first voltage information, d represents the standard error, and SOC represents the state of charge (SOC). volt+d For the first error state of charge information, SOC volt-d The second error charge state information is represented by Tol, which is the second threshold.

[0081] In the embodiments of this application, by calculating the second difference between the first error state of charge information and the second error state of charge information, if the second difference is greater than zero and less than or equal to the second threshold, the first voltage information can be accurately determined to be within the correctable range.

[0082] In some embodiments of this application, in order to accurately determine that the first voltage information is within the correctable range, the second threshold can be determined in the following manner:

[0083] Obtain the pre-set third threshold.

[0084] Divide the third threshold by 2 to obtain the first quotient.

[0085] Round the first quotient down to obtain the second quotient.

[0086] Multiply the second quotient by 2 to obtain the second threshold.

[0087] The third threshold can be a threshold that the user selects according to their needs.

[0088] The first quotient can be the quotient obtained by dividing the third threshold by 2.

[0089] The second quotient can be the quotient obtained by rounding down the first quotient.

[0090] In some embodiments of this application, the user can first select a threshold, namely the third threshold, based on prior experience, and then calculate the third threshold. Specifically, the third threshold can be divided by 2 to obtain the first quotient, and then the first quotient can be rounded down to obtain the second quotient. Then the second quotient can be multiplied by 2 to obtain the accurate second threshold. Based on the second threshold, it can be further determined whether the first voltage information is within the correctable range.

[0091] In the embodiments of this application, by first setting a third threshold and then adjusting the third threshold, a precise second threshold is obtained. Based on the second threshold, it can be further determined whether the first voltage information is within the correctable range.

[0092] In some embodiments of this application, to further improve the accuracy of state of charge correction, after step 110, the battery state of charge correction method described above may further include:

[0093] The first voltage information, first temperature information, and first current information are filtered respectively to obtain the filtered first voltage information, first temperature information, and first current information.

[0094] Step 120 may specifically include:

[0095] If the filtered first voltage information is determined to be in the first state and within the correctable range, the first state of charge information of each individual cell corresponding to the filtered first voltage information, first temperature information and first current information is obtained by querying a pre-built correspondence table.

[0096] In some embodiments of this application, after obtaining the first voltage information, the first temperature information, and the first current information, they can be filtered first. Specifically, they can be filtered using mean filtering, low-pass filtering, etc., which are not limited here.

[0097] In the embodiments of this application, the first voltage information, the first temperature information, and the first current information are filtered respectively to obtain the filtered first voltage information, the first temperature information, and the first current information. This can filter out the influence of noise information on the first voltage information, the first temperature information, and the first current information, thereby avoiding affecting the correction accuracy of the state of charge information.

[0098] In some embodiments of this application, when using the correspondence table, the correspondence table must first be constructed. The construction process of the correspondence table is described in detail below. It should be noted that the construction of the correspondence table can be before step 110 or before step 120. There is no limitation here, as long as the construction is carried out before the use of the correspondence table.

[0099] In some embodiments of this application, the battery state-of-charge correction method described above may further include:

[0100] Multiple sets of historical 3D data were acquired. Each set of historical 3D data includes historical state of charge information, historical temperature information, and historical current information for each individual cell in the battery pack.

[0101] The battery pack is continuously subjected to a preset duration under the operating conditions corresponding to each set of historical 3D data, and the historical voltage information corresponding to each set of historical 3D data is recorded.

[0102] Based on each set of historical 3D data and the corresponding historical voltage information, a corresponding relationship table is constructed.

[0103] The historical 3D data can be 3D data collected within a historical time period. This 3D data includes the historical state of charge (SOC), historical temperature, and historical current information of each individual cell in the battery pack. Specifically, the historical SOC can be the SOC information of each individual cell in the battery pack acquired within the historical time period; the historical temperature information can be the temperature information of the battery pack acquired within the historical time period; and the historical current information can be the current information of the battery pack acquired within the historical time period.

[0104] The preset duration can be the duration that the battery pack will operate under the conditions corresponding to each set of historical 3D data, for example, 1 hour.

[0105] For each set of historical 3D data, the historical voltage information corresponding to that set of historical 3D data can be the voltage information measured under that historical 3D data.

[0106] In one example, the historical state of charge information of three battery packs can be selected as 100%, the historical temperature information as 0℃, and the discharge current (i.e., historical current information) as 1A. After maintaining this condition for 1 hour, the average voltage value of the three battery packs under this condition is recorded, which is the historical voltage information corresponding to the historical three-dimensional data of this set.

[0107] Repeat the above steps to select voltage information under different historical temperatures (e.g., temperatures can be selected between -30°C and 60°C, with a temperature measurement point selected every 5°C), different historical state of charge information (e.g., historical state of charge information can be selected from 0% to 100%, with a state of charge measurement point selected every 10%), and different historical current information (e.g., historical current information can be selected from 1A to 5A, with a current measurement point selected every 1A). After sorting, obtain the corresponding relationship table.

[0108] In some embodiments of this application, after obtaining historical voltage information corresponding to different historical three-dimensional data through testing, the voltage lookup table scale can be determined. Specifically, the minimum voltage appearing in the table can be the minimum scale, with an interval of 5mV. The maximum scale should be greater than the maximum voltage value in the table. Then, by looking up the SOC through voltage, the SOC table for the three dimensions of temperature, voltage, and current can be obtained.

[0109] In the embodiments of this application, by acquiring multiple sets of historical three-dimensional data, and then continuously recording the historical voltage information corresponding to each set of historical three-dimensional data under the operating conditions corresponding to each set of historical three-dimensional data for a preset duration, a corresponding relationship table can be accurately constructed based on each set of historical three-dimensional data and the historical voltage information corresponding to each set of historical three-dimensional data.

[0110] In some embodiments of this application, in order to expand the lookup range of the correspondence table, the data in the constructed correspondence table can be interpolated to obtain a correspondence table with a larger data range. The specific implementation is as follows:

[0111] The construction of a correspondence table based on each set of historical 3D data and the corresponding historical voltage information can specifically include:

[0112] Based on each set of historical 3D data and the corresponding historical voltage information, an initial correspondence table is constructed.

[0113] Based on a preset interpolation algorithm, interpolation is performed on each set of historical 3D data and the historical voltage information corresponding to each set of historical 3D data in the initial correspondence table to obtain multiple sets of target historical data. Each set of target historical data includes target historical 3D data obtained after interpolation of historical 3D data, and target historical voltage information corresponding to the target historical 3D data.

[0114] Based on multiple sets of historical target data, a corresponding relationship table is obtained.

[0115] The initial correspondence table can be constructed based on each set of historical three-dimensional data and the historical voltage information corresponding to each set of historical three-dimensional data.

[0116] The target historical data can be obtained by interpolating historical three-dimensional data and historical voltage information corresponding to the historical three-dimensional data.

[0117] The target 3D data can be 3D data obtained by interpolating historical 3D data.

[0118] The preset interpolation algorithm can be a pre-set interpolation algorithm, specifically an internal interpolation method or an external interpolation algorithm. For example, the internal interpolation algorithm can be selected as Linearpoint-slope, and the external interpolation method can be selected as Clip interpolation.

[0119] In the embodiments of this application, an initial correspondence table is constructed based on each set of historical three-dimensional data and the historical voltage information corresponding to each set of historical three-dimensional data. Then, based on a preset interpolation algorithm, interpolation is performed on each set of historical three-dimensional data and the historical voltage information corresponding to each set of historical three-dimensional data in the initial correspondence table to obtain multiple sets of target historical data. Based on multiple sets of target historical data, a correspondence table is obtained. In this way, a correspondence table with a wider range of data can be obtained. Thus, when looking up the table, it can be ensured that the state of charge information under the corresponding operating condition is obtained, thereby improving the accuracy of the correction of the state of charge information.

[0120] Step 130: Correct the current state of charge information of each individual cell based on the first state of charge information of each individual cell to obtain the target state of charge information of each individual cell.

[0121] The target state of charge information can be the state of charge information obtained by correcting the first state of charge information of each individual cell.

[0122] In some embodiments of this application, in order to accurately correct the state of charge information of each individual cell in the battery pack, step 130 may specifically include:

[0123] The first state of charge information of each individual cell is integrated in ampere-hours to obtain the integrated first state of charge information.

[0124] The integrated first state of charge information of each individual cell is used as the target state of charge information of each individual cell.

[0125] In some embodiments of this application, since the battery pack is generally left to stand for a period of time before being used again when the state of charge information of each individual cell is corrected, for each individual cell, the first state of charge information of the individual cell can be integrated in ampere-hours during the resting period to obtain the integrated first state of charge information, and then the integrated first state of charge information is determined as the target state of charge information of the individual cell, which is the corrected state of charge information.

[0126] In the embodiments of this application, the first state of charge information of each individual cell is integrated in ampere-hours to obtain the integrated first state of charge information. Then, the integrated first state of charge information of each individual cell can be used as the target state of charge information of each individual cell, thus enabling precise correction of the state of charge information of each individual cell.

[0127] In some embodiments of this application, to further enhance the user experience, after step 130, the battery state-of-charge correction method described above may further include:

[0128] Displays the target state of charge information.

[0129] In some embodiments of this application, after obtaining the target state of charge information, the target state of charge information can be displayed on the vehicle, specifically on the vehicle's dashboard.

[0130] In the embodiments of this application, after obtaining the target state of charge information, the target state of charge information is displayed so that the user can intuitively view the target state of charge information, thereby allowing the user to intuitively view the remaining battery power of the car and improving the user experience.

[0131] In some embodiments of this application, when displaying target state of charge information, the target state of charge information displayed on the car's dashboard may change abruptly. For example, before the state of charge information is corrected, the remaining battery level displayed on the dashboard is 50%, and after the correction, the state of charge information is 55%. In this case, the state of charge information displayed on the dashboard will jump directly from 50% to 55%, which will affect the user experience.

[0132] To address the aforementioned issues, the display of target state of charge information may specifically include:

[0133] Set a single-cycle variation limit for the target state of charge information to be displayed to obtain the filtered target state of charge information.

[0134] Displays the filtered target state of charge information.

[0135] In the embodiments of this application, the corrected target state of charge information to be displayed can be filtered. Specifically, a single-cycle change limit can be set on the target state of charge information to be displayed to obtain the filtered target state of charge information. Then, the car displays the filtered target state of charge information, thus avoiding jumps in the displayed target state of charge information.

[0136] In one example, if the remaining charge displayed on the dashboard is 50% before the charge status information is corrected, and 55% after the correction, then a single-cycle change limit can be set for the charge status information to be displayed. This means setting a maximum range for each change in the remaining charge, and each change should not exceed this range. For example, if the single-cycle change limit is set to 2%, then the charge displayed on the dashboard will first change from 50% to 52%, then from 52% to 54%, then from 54% to 55%, and finally the remaining charge displayed on the dashboard will stabilize at 55%.

[0137] In the embodiments of this application, by setting a single-cycle change limit for the target state of charge information to be displayed, the displayed target state of charge information can be prevented from jumping, thus improving the user experience.

[0138] In some embodiments of this application, high-power lithium iron phosphate batteries are often used as low-voltage power sources in practical applications. During vehicle operation, the DC / DC module's charging management of the low-voltage power supply, the vehicle's timed wake-up function for intelligent low-voltage power replenishment, and the determination of the low-voltage power supply's charge level before OTA upgrades all place high demands on the accuracy of its State of Charge (SOC). The battery state of charge correction method provided in this application can improve the accuracy of SOC estimation in practical applications. Specifically, the error calculated using the ampere-hour integration method can accumulate during use. Periodically correcting the low-voltage power supply's SOC using the method of this application can eliminate this accumulated error and improve the SOC accuracy of the low-voltage power supply.

[0139] It should be noted that the battery state of charge correction method provided in this application embodiment can be executed by a battery state of charge correction device or a control module in the battery state of charge correction device for executing the battery state of charge correction method.

[0140] Based on the same inventive concept as the aforementioned battery state of charge correction method, this application also provides a battery state of charge correction device. The following is in conjunction with... Figure 3 The battery state of charge correction device provided in the embodiments of this application will be described in detail.

[0141] Figure 3 This is a schematic diagram of a battery state of charge correction device according to an exemplary embodiment.

[0142] like Figure 3 As shown, the battery state of charge correction device 300 may include:

[0143] The acquisition module 310 is used to acquire the first voltage information of each individual cell in the battery pack, the first temperature information of the battery pack, and the first current information of the battery pack at the current moment.

[0144] The determining module 320 is configured to, when determining that the first voltage information is in a first state and the first voltage information is within a correctable range, query a pre-built correspondence table based on the first voltage information, the first temperature information, and the first current information to obtain the first state of charge information of each individual cell corresponding to the first voltage information, the first temperature information, and the first current information. The correspondence table contains the correspondence between the voltage information of the individual cell, the temperature information of the battery pack, the current information of the battery pack, and the state of charge information.

[0145] The determining module 320 is further configured to correct the current state of charge information of each individual cell based on the first state of charge information of each individual cell, so as to obtain the target state of charge information of each individual cell.

[0146] In the embodiments of this application, by acquiring the first voltage information, the first temperature information, and the first current information of each individual cell in the battery pack at the current moment, and determining that the first voltage information is in a first state and within a correctable range, a query is performed in a pre-constructed correspondence table based on the first voltage information, the first temperature information, and the first current information to obtain the first state of charge information of each individual cell corresponding to the first voltage information, the first temperature information, and the first current information. Based on the first state of charge information of each individual cell, the current state of charge information of each individual cell is corrected to obtain the target state of charge information of each individual cell. Since the correspondence table contains the correspondence between the voltage information of the individual cell, the temperature information of the battery pack, the current information of the battery pack, and the state of charge information, compared with the correspondence table in the prior art which only has the correspondence between state of charge information and voltage information, the correspondence provided in the embodiments of this application contains both voltage information and the temperature and current information of the battery pack. This avoids the influence of small current discharge and temperature on the correction of state of charge information when the battery pack is stationary, thus improving the correction accuracy of the state of charge information of the battery pack.

[0147] In some embodiments of this application, in order to accurately determine whether the first voltage information is in a first state, the acquisition module 310 may specifically be used to: acquire the second voltage information of each individual cell in the battery pack at the current time of the last acquisition.

[0148] The aforementioned battery state-of-charge correction device may further include:

[0149] The calculation module is used to calculate the first difference between the first voltage information and the second voltage information.

[0150] The determination module 320 can also be used for:

[0151] Obtain the absolute value of the first difference.

[0152] If the ratio of the absolute value to the first duration is less than or equal to the first threshold, the state information of the first voltage information is determined to be the first state, wherein the first duration is the duration between the current time and the previous time of the current time.

[0153] In some embodiments of this application, in order to accurately determine whether the first voltage information is within the correctable range, the acquisition module 310 may specifically be used to: acquire the pre-set standard error of each individual cell of the battery pack.

[0154] The calculation module can also be used to calculate first error voltage information and second error voltage information of the first voltage information under the standard error.

[0155] The determining module 320 can also be used to: query the corresponding relationship table according to the first temperature information and the first current information to obtain the first error state of charge information under the first error voltage information and the second error state of charge information under the second error voltage information, and determine whether the first voltage information is within the correctable range according to the first error state of charge information and the second error state of charge information.

[0156] In some embodiments of this application, in order to further accurately determine whether the first voltage information is within the correctable range, the calculation module can also be used to calculate a second difference between the first error state of charge information and the second error state of charge information.

[0157] The determining module 320 can also be used to: determine the first voltage information within the correctable range when the second difference is greater than zero and the second difference is less than or equal to the second threshold.

[0158] In some embodiments of this application, the acquisition module 310 can specifically be used to: acquire multiple sets of historical three-dimensional data, wherein each set of historical three-dimensional data includes historical state of charge information, historical temperature information, and historical current information of each individual cell in the battery pack.

[0159] The aforementioned battery state-of-charge correction device may further include:

[0160] The recording module is used to continuously record the historical voltage information corresponding to each set of historical three-dimensional data for a preset duration under the operating conditions corresponding to each set of historical three-dimensional data.

[0161] A construction module is used to construct the correspondence table based on each set of historical three-dimensional data and the historical voltage information corresponding to each set of historical three-dimensional data.

[0162] In some embodiments of this application, in order to further improve the correction accuracy of the battery pack's state of charge information, the construction module can specifically be used for:

[0163] Based on each set of historical 3D data and the corresponding historical voltage information, an initial correspondence table is constructed.

[0164] Based on a preset interpolation algorithm, interpolation is performed on each set of historical 3D data in the initial correspondence table and the historical voltage information corresponding to each set of historical 3D data to obtain multiple sets of target historical data. Each set of target historical data includes target historical 3D data obtained after interpolation of the historical 3D data, and target historical voltage information corresponding to the target historical 3D data.

[0165] Based on the aforementioned sets of historical target data, the corresponding relationship table is obtained.

[0166] In some embodiments of this application, in order to further improve the correction accuracy of the battery pack's state of charge information, the determining module 320 may specifically be used for:

[0167] The first state of charge information of each individual cell is integrated in ampere-hours to obtain the integrated first state of charge information.

[0168] The integrated first state of charge information of each individual cell is used as the target state of charge information of each individual cell.

[0169] In some embodiments of this application, to improve user experience, the battery state-of-charge correction device described above may further include:

[0170] The display module is used to display the target state of charge information.

[0171] In some embodiments of this application, the display module may specifically include:

[0172] The processing unit is used to set a single-cycle variation limit on the target state of charge information to be displayed, and to obtain filtered target state of charge information.

[0173] The display unit is used to display the filtered target state of charge information.

[0174] The battery state of charge correction device provided in this application embodiment can be used to execute the battery state of charge correction methods provided in the above method embodiments. The implementation principle and technical effect are similar, and will not be described in detail here for the sake of brevity.

[0175] Based on the same inventive concept, embodiments of this application also provide an electronic device.

[0176] Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. For example... Figure 4 As shown, the electronic device may include a processor 401 and a memory 402 storing computer programs or instructions.

[0177] Specifically, the processor 401 may include a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of the present invention.

[0178] Memory 402 may include mass storage for data or instructions. For example, and not limitingly, memory 402 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 402 may include removable or non-removable (or fixed) media. Where appropriate, memory 402 may be internal or external to the integrated gateway disaster recovery device. In a particular embodiment, memory 402 is non-volatile solid-state memory. Memory may include read-only memory (ROM), random-access memory (RAM), disk storage media devices, optical storage media devices, flash memory devices, electrical, optical, or other physical / tangible memory storage devices. Therefore, typically, a memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described in the battery state-of-charge correction method provided in the above embodiments.

[0179] The processor 401 reads and executes computer program instructions stored in the memory 402 to implement any of the battery state of charge correction methods in the above embodiments.

[0180] In one example, the electronic device may also include a communication interface 403 and a bus 410. For example, Figure 4 As shown, the processor 401, memory 402, and communication interface 403 are connected through bus 410 and complete communication with each other.

[0181] The communication interface 403 is mainly used to realize communication between various modules, devices, units and / or devices in the embodiments of the present invention.

[0182] Bus 410 includes hardware, software, or both, that couples components of an electronic device together. For example, and not limitingly, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 410 may include one or more buses. While specific buses are described and illustrated in embodiments of the invention, the invention contemplates any suitable bus or interconnect.

[0183] The electronic device can execute the battery state-of-charge correction method in the embodiments of the present invention, thereby achieving... Figure 1 The method for correcting the state of charge of a battery is described.

[0184] Furthermore, in conjunction with the battery state-of-charge correction methods in the above embodiments, this invention can be implemented using a readable storage medium. This readable storage medium stores program instructions, which, when executed by a processor, implement any of the battery state-of-charge correction methods described in the above embodiments.

[0185] In addition, in conjunction with the battery state of charge correction method in the above embodiments, the present invention can provide a computer program product, wherein when the instructions in the computer program product are executed by the processor of an electronic device, the electronic device performs any of the battery state of charge correction methods in the above embodiments.

[0186] It should be clarified that the present invention is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of the present invention.

[0187] The functional blocks shown in the above-described structural diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this invention are programs or code segments used to perform the required tasks. The programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0188] It should also be noted that the exemplary embodiments mentioned in this invention describe methods or systems based on a series of steps or apparatus. However, this invention is not limited to the order of the steps described above; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0189] The aspects of this application have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by dedicated hardware performing the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

[0190] The above description is merely a specific embodiment of the present invention. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A method for correcting the state of charge of a battery, characterized in that, The method includes: Obtain the first voltage information of each individual cell in the battery pack, the first temperature information of the battery pack, and the first current information of the battery pack at the current moment. Obtain the second voltage information of each individual cell in the battery pack from the last collected data at the current time. Calculate the first difference between the first voltage information and the second voltage information. Obtain the absolute value of the first difference; If the ratio of the absolute value to the first duration is less than or equal to the first threshold, the state information of the first voltage information is determined to be the first state, wherein the first duration is the duration between the current time and the last acquisition time of the current time; If it is determined that the first voltage information is in the first state and the first voltage information is within a correctable range, a lookup is performed in a pre-built correspondence table based on the first voltage information, the first temperature information, and the first current information to obtain the first state of charge information of each individual cell corresponding to the first voltage information, the first temperature information, and the first current information. The correspondence table contains the correspondence between the voltage information of the individual cell, the temperature information of the battery pack, the current information of the battery pack, and the state of charge information. Based on the first state of charge information of each individual cell, the current state of charge information of each individual cell is corrected to obtain the target state of charge information of each individual cell.

2. The method according to claim 1, characterized in that, After acquiring the first voltage information of each individual cell in the battery pack, the first temperature information of the battery pack, and the first current information of the battery pack at the current moment, the method further includes: Obtain the pre-set standard error of each individual cell in the battery pack. Calculate the first error voltage information and the second error voltage information under the standard error of the first voltage information. Based on the first temperature information and the first current information, the corresponding relationship table is consulted to obtain the first error state of charge information under the first error voltage information and the second error state of charge information under the second error voltage information, respectively. Based on the first error state of charge information and the second error state of charge information, determine whether the first voltage information is within the correctable range.

3. The method according to claim 2, characterized in that, The step of determining whether the first voltage information is within the correctable range based on the first error state of charge information and the second error state of charge information includes: Calculate the second difference between the first error state-of-charge information and the second error state-of-charge information. If the second difference is greater than zero and the second difference is less than or equal to the second threshold, the first voltage information is determined to be within the correctable range.

4. The method according to claim 1, characterized in that, The step of correcting the current state of charge (SOC) information of each individual cell based on the first SOC information of each individual cell to obtain the target SOC information of each individual cell includes: The first state of charge information of each individual cell is integrated in ampere-hours to obtain the integrated first state of charge information. The integrated first state of charge information of each individual cell is used as the target state of charge information of each individual cell.

5. The method according to claim 1, characterized in that, Before acquiring the first voltage information of each individual cell in the battery pack, the first temperature information of the battery pack, and the first current information of the battery pack at the current moment, the method further includes: Multiple sets of historical 3D data were acquired. Each set of historical 3D data includes historical state of charge information, historical temperature information, and historical current information for each individual cell in the battery pack. The battery pack is continuously subjected to the operating conditions corresponding to each set of historical three-dimensional data for a preset duration, and the historical voltage information corresponding to each set of historical three-dimensional data is recorded. Based on each set of historical three-dimensional data and the historical voltage information corresponding to each set of historical three-dimensional data, the correspondence table is constructed.

6. The method according to claim 5, characterized in that, The step of constructing the correspondence table based on each set of historical three-dimensional data and the historical voltage information corresponding to each set of historical three-dimensional data includes: Based on each set of historical 3D data and the corresponding historical voltage information, an initial correspondence table is constructed. Based on a preset interpolation algorithm, interpolation is performed on each set of historical 3D data in the initial correspondence table and the historical voltage information corresponding to each set of historical 3D data to obtain multiple sets of target historical data. Each set of target historical data includes target historical 3D data obtained after interpolation of the historical 3D data, and target historical voltage information corresponding to the target historical 3D data. Based on the aforementioned sets of historical target data, the corresponding relationship table is obtained.

7. The method according to claim 1, characterized in that, After correcting the current state of charge information of each individual cell based on the first state of charge information of each individual cell to obtain the target state of charge information of each individual cell, the method further includes: Display the target state of charge information.

8. The method according to claim 7, characterized in that, The display of the target state of charge information includes: A single-cycle variation limit is set on the target state of charge information to be displayed to obtain filtered target state of charge information. Displays the filtered target state of charge information.

9. A battery state of charge correction device, characterized in that, The device includes: The acquisition module is used to acquire the first voltage information of each individual cell in the battery pack, the first temperature information of the battery pack, and the first current information of the battery pack at the current moment. The acquisition module is further configured to acquire the second voltage information of each individual cell in the battery pack from the last acquisition at the current time. The calculation module is used to calculate the first difference between the first voltage information and the second voltage information. The acquisition module is further configured to acquire the absolute value of the first difference; The determination module is used to determine the state information of the first voltage information as a first state when the ratio of the absolute value to the first duration is less than or equal to a first threshold, wherein the first duration is the duration between the current time and the last acquisition time of the current time; The determining module is further configured to, when determining that the first voltage information is in a first state and the first voltage information is within a correctable range, query a pre-built correspondence table based on the first voltage information, the first temperature information, and the first current information to obtain the first state of charge information of each individual cell corresponding to the first voltage information, the first temperature information, and the first current information. The correspondence table contains the correspondence between the voltage information of the individual cell, the temperature information of the battery pack, the current information of the battery pack, and the state of charge information. The determining module is further configured to correct the current state of charge information of each individual cell based on the first state of charge information of each individual cell, so as to obtain the target state of charge information of each individual cell.

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