Battery electric quantity correction method and device, vehicle and computer readable storage medium

Abstract

The invention provides a battery electric quantity correction method and device, a vehicle and a computer readable storage medium, and relates to the technical field of vehicles, and the method comprises the steps: judging whether a power-off event of the vehicle is triggered or not when the correction condition of the remaining electric quantity of a battery pack is satisfied; if yes, executing depolarization operation of the battery pack; under the condition that depolarization of the battery pack is completed, obtaining a voltage extreme value in voltages of all single batteries of the battery pack; and correcting the remaining capacity of the battery pack according to the voltage extreme value. According to the invention, active correction of the SOC of the vehicle battery pack can be realized, and the accuracy of SOC estimation can be improved.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and more specifically, to a battery charge correction method, device, vehicle and computer-readable storage medium in the field of vehicle technology. Background Art

[0002] The battery state of charge (SOC) calibration strategy currently used in the battery management system (BMS) mainly calibrates the battery SOC through specific external conditions or events. Although this strategy is effective in some simple scenarios, it has problems such as high dependence, uncertain calibration timing, and error accumulation after long-term use, and cannot provide accurate SOC estimation. Summary of the invention

[0003] The present application provides a battery charge correction method, device, vehicle and computer-readable storage medium. The present application realizes active correction of the SOC of a vehicle battery pack, which is beneficial to improving the accuracy of SOC estimation.

[0004] In a first aspect, a battery power correction method is provided, the battery power correction method comprising: when a correction condition for the remaining power of a battery pack is met, determining whether a power-off event of a vehicle is triggered; if so, performing a depolarization operation of the battery pack; when the depolarization of the battery pack is completed, obtaining a voltage extreme value among the voltages of all single cells of the battery pack; and correcting the remaining power of the battery pack according to the voltage extreme value.

[0005] Based on the above technical scheme, the embodiment of the present application adopts a technical scheme of judging whether a power-off event of the vehicle is triggered when a correction condition for the remaining power of the battery pack is met, and if the power-off event of the vehicle is triggered, performing a depolarization operation of the battery pack, and correcting the remaining power of the battery pack according to the voltage extremes in the voltages of all the single cells of the battery pack when the depolarization of the battery pack is completed. When it is detected that the SOC of the battery pack needs to be corrected, the SOC of the battery pack is actively corrected when the user stops using the vehicle, which solves the problems of uncertain SOC calibration timing and error accumulation after long-term use in traditional passive calibration strategies, and not only improves the frequency and quality of SOC calibration, but also improves the accuracy of SOC estimation.

[0006] In a possible implementation, the voltage extreme value includes a maximum cell voltage and a minimum cell voltage, and the correction of the remaining power of the battery pack according to the voltage extreme value includes: querying a first mapping table about an open circuit voltage and a first preset remaining power according to the maximum cell voltage to obtain a first power; querying the first mapping table according to the minimum cell voltage to obtain a second power; and correcting the remaining power of the battery pack according to the first power and the second power. By using the maximum cell voltage and the minimum cell voltage when the battery pack is depolarized to correct the SOC of the battery pack, the accuracy of SOC estimation, system safety and reliability can be significantly improved, energy management can be optimized, and user experience can be improved.

[0007] In one possible implementation, correcting the remaining power of the battery pack based on the first power and the second power includes: querying a second mapping relationship based on the extreme power to obtain a target remaining power; wherein the extreme power includes the first power and the second power, the second mapping relationship includes a plurality of preset extreme power and each of the plurality of preset extreme power corresponds to a second preset remaining power; and correcting the remaining power of the battery pack to the target remaining power.

[0008] In one possible implementation, querying a first mapping table about open circuit voltage and a first preset remaining power according to the maximum cell voltage to obtain the first power includes: when the first mapping table includes the maximum cell voltage, determining the first preset remaining power corresponding to the open circuit voltage that is the same as the maximum cell voltage in the first mapping table as the first power; when the first mapping table does not include the maximum cell voltage, determining the first power based on the voltage value in the first mapping table and a difference algorithm.

[0009] In a possible implementation, before executing the depolarization operation of the battery pack, the battery power correction method further includes: maintaining the connection between the battery pack and the vehicle load, so that after the power-off event of the vehicle is triggered, the connection between the battery pack and the vehicle load is not immediately disconnected, but the switch module between the battery pack and the vehicle load is controlled to be closed to continue to maintain the connection between the battery pack and the vehicle load, and the battery pack is controlled to discharge with a small current until the depolarization of the battery pack is completed, thereby shortening the time for the battery management system to wait for the correction of the SOC, which is conducive to completing the correction of the SOC in a short time. After correcting the remaining power of the battery pack according to the voltage extreme value, the battery power correction method further includes: disconnecting the connection between the battery pack and the vehicle load.

[0010] In one possible implementation, the battery power correction method further includes: obtaining the cumulative discharge capacity of the battery pack while maintaining the connection between the battery pack and the vehicle load; and determining that depolarization of the battery pack is completed when the cumulative discharge capacity is greater than or equal to a first threshold.

[0011] In one possible implementation, when the correction condition for the remaining power of the battery pack is met, before determining whether a power-off event of the vehicle is triggered, the battery power correction method also includes: obtaining the cumulative charge and discharge amount of the battery pack; when the cumulative charge and discharge amount is greater than a second threshold, determining whether the difference between the remaining power of the battery pack at any adjacent moments is less than or equal to a third threshold; if so, determining that the correction condition is met; if not, determining that the correction condition is not met.

[0012] In a second aspect, a battery power correction device is provided, the battery power correction device comprising:

[0013] An event determination module, used to determine whether a power-off event of the vehicle is triggered when a correction condition of the remaining power of the battery pack is met;

[0014] A battery control module, configured to perform a depolarization operation of the battery pack when the power-off event is triggered;

[0015] A voltage acquisition module, used for acquiring the voltage extreme value of all the single cells of the battery pack when the depolarization of the battery pack is completed;

[0016] A power correction module is used to correct the remaining power of the battery pack according to the voltage extreme value.

[0017] In a possible implementation, the voltage extremes include a maximum cell voltage and a minimum cell voltage, and the power correction module includes:

[0018] A first query unit, configured to query a first mapping table of an open circuit voltage and a first preset remaining power according to the maximum cell voltage to obtain a first power;

[0019] A second query unit, configured to query the first mapping table according to the minimum cell voltage to obtain a second power;

[0020] A correction unit is used to correct the remaining power of the battery pack according to the first power and the second power.

[0021] In one possible implementation, the correction unit is specifically used to query a second mapping relationship based on the extreme value power to obtain a target remaining power; wherein the extreme value power includes the first power and the second power, the second mapping relationship includes multiple preset extreme value power and the multiple preset extreme value power each corresponds to a second preset remaining power; and the remaining power of the battery pack is corrected to the target remaining power.

[0022] In one possible implementation, the first query unit is specifically used to determine the first preset remaining power corresponding to the open-circuit voltage that is the same as the maximum cell voltage in the first mapping table as the first power when the first mapping table includes the maximum cell voltage; and to determine the first power based on the voltage value and difference algorithm in the first mapping table when the first mapping table does not include the maximum cell voltage.

[0023] In a possible implementation, the battery power correction device includes:

[0024] a device control unit, configured to maintain the connection between the battery pack and a vehicle load before the battery control module performs a depolarization operation of the battery pack;

[0025] The device control unit is further used to disconnect the battery pack from the vehicle load after the power correction module corrects the remaining power of the battery pack according to the voltage extreme value.

[0026] In a possible implementation, the battery power correction device includes:

[0027] A polarization judgment unit is used to obtain the cumulative discharge amount of the battery pack while maintaining the connection between the battery pack and the vehicle load; when the cumulative discharge amount is greater than or equal to a first threshold, determine that the depolarization of the battery pack is completed.

[0028] In one possible implementation, the event judgment module is also used to obtain the cumulative charge and discharge amount of the battery pack; when the cumulative charge and discharge amount is greater than a second threshold, determine whether the difference between the remaining power of the battery pack at any adjacent time is less than or equal to a third threshold; if so, determine that the correction condition is met; if not, determine that the correction condition is not met.

[0029] In a third aspect, a vehicle is provided, comprising a memory and a processor. The memory is used to store executable program code, and the processor is used to call and run the executable program code from the memory, so that the vehicle executes the battery power correction method in the first aspect or any possible implementation of the first aspect.

[0030] In a fourth aspect, a computer program product is provided, comprising: a computer program code, which, when executed on a computer, enables the computer to execute the battery power correction method in the first aspect or any possible implementation of the first aspect.

[0031] In a fifth aspect, a computer-readable storage medium is provided, which stores a computer program code. When the computer program code runs on a computer, the computer executes the battery power correction method in the above-mentioned first aspect or any possible implementation of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic flow chart of a battery power correction method provided in an embodiment of the present application is shown;

[0033] Figure 2 A schematic diagram of an OCV-SOC graph is shown;

[0034] Figure 3 A schematic diagram showing the connection between the battery pack and the vehicle load;

[0035] Figure 4 A schematic diagram of the structure of a battery power correction device provided in an embodiment of the present application is shown;

[0036] Figure 5 A schematic structural diagram of a vehicle provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0037] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0038] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0039] The battery remaining capacity SOC calibration strategy currently used in battery management systems mainly calibrates the battery SOC through specific external conditions or events. This is a passive calibration strategy. Although this strategy is effective in some simple scenarios, it has problems such as high dependence, uncertainty in calibration timing, and error accumulation after long-term use, and cannot provide accurate SOC estimation. Among them, SOC refers to the ratio of the current remaining capacity of the battery to the capacity of the fully charged state, usually expressed as a percentage; in the vehicle field, SOC is used to inform the driver of the current remaining battery capacity to help the driver plan the journey.

[0040] Based on the above problems, the present application provides a battery charge correction method, device, vehicle and computer-readable storage medium. The present application realizes active correction of the SOC of a vehicle battery pack through active intervention, solves the problems of uncertain SOC calibration timing and error accumulation after long-term use in traditional passive calibration strategies, and not only improves the frequency and quality of SOC calibration, but also improves the accuracy of SOC estimation.

[0041] The following is an embodiment of a battery power correction method provided in this application specification.

[0042] Figure 1 A schematic flow chart of a battery power correction method provided in an embodiment of the present application is shown, such as Figure 1 As shown, the battery power correction method provided in the embodiment of the present application is applied to the battery management system of the vehicle. The battery management system is an electronic control system used to monitor and manage the working status of the battery pack and provide safety protection for the battery to ensure that the battery works in the best state, prolong the battery life, and ensure the safe operation of the vehicle; the functions of the battery management system include battery status monitoring (such as voltage, current, temperature, etc.), fault diagnosis, thermal management, etc.

[0043] The above battery power correction method includes the following schemes:

[0044] S110: When the correction condition of the remaining power of the battery pack is met, it is determined whether a power-off event of the vehicle is triggered.

[0045] In an exemplary embodiment, for new energy vehicles (such as hybrid vehicles and electric vehicles), the battery pack generally refers to the vehicle's power battery; for fuel vehicles, the battery pack generally refers to the storage battery. If the battery management system determines that the correction conditions for the current SOC of the battery pack are met through the charge and discharge conditions of the battery pack and the previous remaining SOC of the battery pack, it is considered that the current SOC of the battery pack has not been corrected and needs to be corrected.

[0046] In order to ensure that the SOC of the battery pack seen by the user at any time when using the vehicle is accurate and does not suddenly jump, the correction operation of the SOC is generally performed after the user uses the vehicle. When the correction conditions of the remaining power of the battery pack are met, it is determined whether the power-off event of the vehicle is triggered, specifically to determine whether the user stops using the vehicle. If it is determined that the power-off event of the vehicle is triggered, it means that the user has the intention to stop using the vehicle. Among them, the way to determine whether the power-off event of the vehicle is triggered is determined according to the actual power-off control strategy of the vehicle. Example 1: A class A vehicle is equipped with a power-off switch (such as a physical power-off switch and / or a virtual power-off switch). When the vehicle is stationary, after the user triggers the power-off switch, the battery management system receives the power-off instruction sent by the power-off switch and determines that the power-off event of the vehicle is triggered. Example 2: A class B vehicle is not equipped with a power-off switch. When the vehicle is stationary, the battery management system receives the vehicle lock completion instruction sent by the vehicle lock system and determines that the vehicle power-off event is triggered.

[0047] S120: When a power-off event of the vehicle is triggered, a depolarization operation of the battery pack is performed.

[0048] If the battery pack is not depolarized before correcting the current SOC, a series of problems may occur, which will affect the accuracy of the battery management system and the service life of the battery pack. Failure to depolarize the battery pack will have negative effects including: increasing the estimation error of SOC, affecting the accuracy of battery health status assessment, reducing system safety and reliability, shortening the service life of the battery pack, etc.

[0049] In order to avoid the negative impact that may be caused by not depolarizing the battery pack, after determining that the vehicle's power-off event is triggered (the user stops using the vehicle), the battery management system actively makes advance preparations for executing the current SOC correction operation, that is, it does not immediately correct the current SOC of the battery pack, but instead executes a depolarization operation of the battery pack.

[0050] Executing a depolarization operation of the battery pack may include: disconnecting the battery pack from the vehicle load, and then depolarizing the battery pack by leaving it in a static state; wherein, after disconnecting the battery pack from the vehicle load, the user can intuitively see that the vehicle is powered off (for example, the user sees that the dashboard, various display screens, etc. in the vehicle are all off). Executing a depolarization operation of the battery pack may also include: although the user triggers a power-off event of the vehicle, the vehicle does not immediately disconnect the battery pack from the vehicle load, but continues to maintain the connection between the battery pack and the vehicle load, and then depolarizes the battery pack by discharging with a small current. Among them, in this depolarization method, after the user triggers the vehicle's power-off event, the vehicle will pretend to have been powered off, and the user can also visually see with his own eyes that the vehicle has been powered off. However, in fact, the battery management system will delay responding to the trigger instruction of the vehicle's power-off event, and continue to maintain the connection between the battery pack and the vehicle load. When the depolarization of the battery pack is completed and the subsequent SOC correction operation is completed, it will respond to the trigger instruction of the vehicle's power-off event, thereby disconnecting the battery pack and the vehicle load, that is, the vehicle is truly powered off.

[0051] S130: When the depolarization of the battery pack is completed, obtain the voltage extreme values ​​of the voltages of all the single cells of the battery pack.

[0052] The battery pack is composed of multiple single cells, which are electrically connected in series, parallel or mixed connection, and the electrical properties (voltage, current, capacity) of all single cells are the same. After detecting that the depolarization of the battery pack is completed, the battery management system actively performs a correction operation on the current SOC of the battery pack. The correction process includes: obtaining the voltage extremes of the voltages of all single cells in the battery pack. For example, the battery pack includes 1000 single cells, that is, 1000 voltages can be obtained, so by comparing the sizes of these 1000 voltages, the voltage extremes among these 1000 voltages can be obtained, and the voltage extremes include the maximum and / or minimum values ​​among these 1000 voltages.

[0053] S140: Correct the remaining power of the battery pack according to the voltage extreme value.

[0054] After obtaining the voltage extremes of all single-cell voltages, the target remaining power of the battery pack, i.e., the target SOC, is estimated by the voltage extremes, and the current SOC is corrected to the target SOC, i.e., current SOC = target SOC, thereby achieving correction of the current SOC.

[0055] The embodiment of the present application adopts a technical solution of determining whether a power-off event of the vehicle is triggered when a correction condition for the remaining power of the battery pack is met, and if the power-off event of the vehicle is triggered, performing a depolarization operation of the battery pack, and correcting the remaining power of the battery pack according to the voltage extremes of all the single cells in the battery pack when the depolarization of the battery pack is completed. This achieves a technical solution of actively correcting the SOC of the battery pack when it is detected that the SOC of the battery pack needs to be corrected while the user stops using the vehicle, thereby solving the problems of uncertain SOC calibration timing and error accumulation after long-term use in traditional passive calibration strategies, and not only improving the frequency and quality of SOC calibration, but also improving the accuracy of SOC estimation.

[0056] The following Figure 1 The specific implementation methods of each step in the illustrated embodiment are described as follows:

[0057] In a possible implementation, the voltage extremes include a maximum cell voltage (maximum value) and a minimum cell voltage (minimum value). The above-mentioned correction of the remaining power of the battery pack according to the voltage extremes includes the following steps:

[0058] Querying a first mapping table of open circuit voltage and first preset remaining power according to the maximum cell voltage to obtain a first power;

[0059] According to the minimum cell voltage, query the first mapping table to obtain the second power;

[0060] The remaining power of the battery pack is corrected according to the first power and the second power.

[0061] When there is no vehicle load at both ends of the battery pack, the voltage at both ends of the battery pack is called the open circuit voltage (OCV). The first mapping table between the open circuit voltage and the first preset remaining power is also called the OCV-SOC mapping table. The OCV-SOC mapping table is obtained through the OCV-SOC curve diagram. Figure 2 A schematic diagram of an OCV-SOC curve diagram is shown. Figure 2 As shown, the OCV-SOC mapping table is shown in Table 1, and each SOC value in Table 1 can be understood as the first preset remaining power.

[0062] Table 1

[0063]

[0064]

[0065] After obtaining the maximum cell voltage, the SOC value corresponding to the maximum cell voltage can be queried through Table 1, that is, the first power; similarly, after obtaining the minimum cell voltage, the SOC value corresponding to the minimum cell voltage can be queried through Table 1, that is, the second power. Then, the target SOC of the battery pack is estimated based on the first power and the second power, and the current SOC is corrected to the target SOC.

[0066] By using the maximum cell voltage and minimum cell voltage when the battery pack is depolarized to correct the SOC of the battery pack, the accuracy of SOC estimation, system safety and reliability can be significantly improved, energy management can be optimized, and user experience can be improved.

[0067] In a possible implementation, the first power level and the second power level are used to correct the remaining power of the battery pack, including the following steps:

[0068] Querying a second mapping relationship according to the extreme value power to obtain a target remaining power; wherein the extreme value power includes a first power and a second power, and the second mapping relationship includes a plurality of preset extreme value power and each of the plurality of preset extreme value power corresponds to a second preset remaining power;

[0069] Correct the remaining power of the battery pack to the target remaining power.

[0070] Table 2

[0071]

[0072] The second mapping relationship is shown in Table 2. Each preset extreme value power in Table 2 includes a first preset power corresponding to a maximum cell voltage and a second preset power corresponding to a minimum cell voltage. A1max, A2max, ... can all be understood as the first preset power, and A1min, A2min, ... can all be understood as the second preset power. For example, if the first power is A2max and the second power is A2min, then the target SOC is A2m, that is, the current SOC is corrected to A2m. By querying the second mapping relationship through the extreme value power, the target remaining power is obtained, which can improve the correction efficiency of SOC.

[0073] In a possible implementation, the first power level and the second power level are used to correct the remaining power of the battery pack, including the following steps:

[0074] According to the average value method, the average value of the first power and the second power is used as the target SOC, target SOC=(first power+second power) / 2, and then the current SOC is corrected to the target SOC.

[0075] In a possible implementation, the first power level and the second power level are used to correct the remaining power of the battery pack, including the following steps:

[0076] According to the weighted average method, the first power and the second power are weighted averaged to obtain the target SOC, that is, the target SOC = w1 × the first power + w2 × the second power, and then the current SOC is corrected to the target SOC. Among them, w1 is the weight corresponding to the maximum cell voltage, w2 is the weight corresponding to the minimum cell voltage, and w1 + w2 = 1.

[0077] In a possible implementation, querying a first mapping table about an open circuit voltage and a first preset remaining power according to the maximum cell voltage to obtain the first power includes the following steps:

[0078] In the case where the first mapping table includes the maximum cell voltage, determining a first preset remaining power corresponding to an open circuit voltage that is the same as the maximum cell voltage in the first mapping table as the first power;

[0079] When the first mapping table does not include the maximum cell voltage, the first power is determined according to the voltage values ​​in the first mapping table and a difference algorithm.

[0080] Considering the case where the first mapping table includes the maximum cell voltage and the case where the maximum cell voltage is not included, the method for determining the first power level for the maximum cell voltage is different. If the first mapping table includes the maximum cell voltage, it means that the first power level can be directly obtained by looking up the table, that is, the open circuit voltage that is the same as the maximum cell voltage in the first mapping table is obtained, and the first preset remaining power level corresponding to the obtained open circuit voltage is the first power level. For example, if the maximum cell voltage is 3.64V, then the first power level is 50%.

[0081] If the first mapping table does not include the maximum cell voltage, it means that the first power cannot be directly obtained by looking up the table. Then, the first power is calculated by the voltage value in the first mapping table and the difference algorithm, so that the first power can be accurately obtained even when the first mapping table does not include the maximum cell voltage. For example, the maximum cell voltage is 3.70V, and 3.70V does not exist in Table 1. The linear difference formula is used to calculate the first power corresponding to the maximum cell voltage. The linear difference formula is as follows:

[0082]

[0083] For example, SOC = 3.70V, OCV1 = 3.64V, SOC1 = 50%, OCV2 = 3.74V, SOC2 = 60%, SOC 插 =56%, that is, the first electric quantity corresponding to the maximum single cell voltage is 56%.

[0084] In a possible implementation, querying the first mapping table according to the minimum cell voltage to obtain the second power includes the following steps:

[0085] In the case where the first mapping table includes the minimum cell voltage, determining the first preset remaining power corresponding to the open circuit voltage that is the same as the minimum cell voltage in the first mapping table as the second power;

[0086] When the first mapping table does not include the minimum cell voltage, the second electrical quantity is determined according to the voltage values ​​in the first mapping table and the difference algorithm.

[0087] The first mapping table includes the case where the minimum single cell voltage is included and the case where the minimum single cell voltage is not included. The method for determining the second electric quantity is the same as the method for determining the first electric quantity when the first mapping table includes the case where the maximum single cell voltage is included and the case where the maximum single cell voltage is not included. The embodiments of the present application will not be repeated here.

[0088] In one possible implementation, Figure 3 As shown, Figure 3 The schematic diagram of the connection between the battery pack and the vehicle load is shown, D represents the battery pack, R represents the vehicle load, K represents the switch module, and the switch module is connected between the battery pack and the vehicle load. When the switch module is closed, the connection between the battery pack and the vehicle load is turned on, and the battery pack and the vehicle load form a loop; when the switch module is disconnected, the connection between the battery pack and the vehicle load is disconnected, and the battery pack and the vehicle load cannot form a loop. Among them, the switch module can be a relay, or a switch circuit composed of switch tubes such as triodes and MOS tubes.

[0089] Before performing the depolarization operation of the battery pack, the battery power correction method further includes the following steps:

[0090] Maintain the connection between the battery pack and the vehicle load.

[0091] Considering that the depolarization time in the static mode is relatively long, the battery management system has to wait for a long time to correct the SOC, resulting in the inability to complete the SOC correction in a short time. Therefore, in order to complete the SOC correction in a short time, after the vehicle power-off event is triggered, the connection between the battery pack and the vehicle load is not disconnected immediately, but the switch module between the battery pack and the vehicle load is controlled to close to continue to maintain the connection between the battery pack and the vehicle load, and control the battery pack to discharge with a small current until the battery pack depolarization is completed, thereby shortening the time the battery management system has to wait for the SOC correction, which is conducive to completing the SOC correction in a short time. Figure 3 As shown, Figure 3 The switch module in the circuit is a relay. During the depolarization of the battery pack, the relay is always in a closed state, that is, the battery pack and the vehicle load are always connected.

[0092] After the remaining power of the battery pack is corrected according to the voltage extreme value, the battery power correction method further includes the following steps:

[0093] Disconnect the battery pack from the vehicle load.

[0094] Since the relay is always in a closed state during the depolarization of the battery pack and the correction of the SOC, the vehicle is not actually powered off. After the correction of the current SOC of the battery pack is completed, the control switch module is disconnected to disconnect the connection between the battery pack and the vehicle load, thus achieving real power-off control of the vehicle. Figure 3 As shown, Figure 3 The switch module in the circuit is a relay. After the current SOC correction of the battery pack is completed, the relay is in a disconnected state, and the connection between the battery pack and the vehicle load is disconnected.

[0095] In a possible implementation, the battery power correction method further includes the following steps:

[0096] While maintaining the connection between the battery pack and the vehicle load, obtaining the accumulated discharge amount of the battery pack;

[0097] When the accumulated discharge amount is greater than or equal to the first threshold, it is determined that the battery pack depolarization is completed.

[0098] Since the depolarization operation of the battery pack is performed while the battery pack is connected to the vehicle load and the battery pack is controlled to discharge at a low current, the judgment of whether the depolarization of the battery pack is completed is specifically to obtain the cumulative discharge amount of the battery pack while maintaining the connection between the battery pack and the vehicle load. The cumulative discharge amount is the sum of the discharge amounts during the depolarization process of the battery pack. Whether the depolarization of the battery pack is completed is judged by the relationship between the cumulative discharge amount and the first threshold value (i.e., the discharge amount threshold value). If the cumulative discharge amount is greater than or equal to the first threshold value, it indicates that the depolarization of the battery pack is completed; if the cumulative discharge amount is less than the first threshold value, it indicates that the depolarization of the battery pack is not completed, and the step of obtaining the cumulative discharge amount of the battery pack is returned until the depolarization of the battery pack is determined to be completed by the relationship between the cumulative discharge amount and the first threshold value, thereby executing the subsequent SOC correction operation, i.e., executing the step of obtaining the voltage extreme value in the voltage of all the single cells of the battery pack.

[0099] In a possible implementation, when the correction condition of the remaining power of the battery pack is met, before determining whether the power-off event of the vehicle is triggered, the battery power correction method further includes:

[0100] Get the cumulative charge and discharge capacity of the battery pack;

[0101] When the accumulated charge and discharge amount is greater than the second threshold, determining whether the difference between the remaining power of the battery pack at any adjacent time is less than or equal to a third threshold;

[0102] If so, it is determined that the correction condition is satisfied;

[0103] If not, it is determined that the correction condition is not satisfied.

[0104] The judgment process of whether the correction conditions of SOC are met includes: before each correction of SOC, the charge and discharge amount of the battery pack will be accumulated to obtain the accumulated charge and discharge amount, that is, the accumulated charge and discharge amount = charge amount + discharge amount. After obtaining the accumulated charge and discharge amount, the relationship between the accumulated charge and discharge amount and the second threshold is determined, and the second threshold is N times the rated capacity of the battery pack, and N is a positive integer greater than or equal to 2. If the accumulated charge and discharge amount is greater than the second threshold, it is preliminarily considered that the SOC of the battery pack needs to be corrected, and it is further determined whether the SOC of the battery pack has been corrected in the past. Determining whether the SOC of the battery pack has been corrected in the past includes determining whether the difference between the remaining power of the battery pack at any adjacent moments is less than or equal to the third threshold value when the cumulative charge and discharge amount is greater than the second threshold value. For example, if it is determined that the difference between the SOC at the tth moment (the current moment) and the SOC at the t-1th moment is greater than the third threshold value, it means that the SOC of the battery pack has been corrected in the past, and the subsequent correction operation may not be performed; if it is determined that the difference between the SOC at the tth moment (the current moment) and the SOC at the t-1th moment is less than or equal to the third threshold value, it means that the SOC of the battery pack has not been corrected in the past, and the subsequent correction operation needs to be performed, that is, further determining that the SOC of the battery pack needs to be corrected. After the current SOC of the battery pack is corrected, the cumulative charge and discharge amount of the battery pack is reset to zero and accumulated again from zero.

[0105] By judging whether the difference between the remaining power of the battery pack at any adjacent moments is less than or equal to the third threshold value when the cumulative charge and discharge amount is greater than the second threshold value, the accuracy of judging whether the SOC of the battery pack needs to be corrected is improved, thereby avoiding the situation where the SOC needs to be corrected when it is not necessary.

[0106] The following is an embodiment of a battery power correction method provided in this application specification.

[0107] A battery power correction method provided in this application specification includes the following schemes:

[0108] S210: Obtain the cumulative charge and discharge amount of the battery pack; wherein, before each correction of the SOC, the charge and discharge amount of the battery pack are accumulated to obtain the cumulative charge and discharge amount, that is, the cumulative charge and discharge amount = charge amount + discharge amount.

[0109] S211: Determine whether the accumulated charge and discharge amount is greater than a second threshold value. If so, it indicates that the SOC of the battery pack needs to be corrected, and execute S212; if not, execute S210.

[0110] S212: Determine whether the difference between the SOCs of the battery packs at any adjacent moments is less than or equal to a third threshold value. If so, it indicates that the SOC of the battery pack has not been corrected before, and it also indicates that it is further considered that the SOC of the battery pack needs to be corrected, and execute S213; if not, do not perform the SOC correction operation.

[0111] S213: Determine whether the vehicle power-off event is triggered. If so, it indicates that the user intends to stop using the vehicle, and execute S214; if not, execute S212.

[0112] S214: Control the switch module between the battery pack and the vehicle load to close to maintain the connection between the battery pack and the vehicle load, and perform a depolarization operation of the battery pack. Specifically, while maintaining the connection between the battery pack and the vehicle load, the battery pack is controlled to discharge with a small current for depolarization.

[0113] S215: Obtain the cumulative discharge capacity of the battery pack.

[0114] S216: Determine whether the accumulated discharge amount is greater than or equal to the first threshold value to determine whether the depolarization of the battery pack is completed. If yes, execute S217; if not, execute S215;

[0115] S217: Obtain the maximum cell voltage (ie, the maximum value) and the minimum cell voltage (ie, the minimum value) of all the cell voltages of the battery pack.

[0116] S218: query the first mapping table about the open circuit voltage and the first preset remaining power according to the maximum cell voltage to obtain the first power, and query the first mapping table according to the minimum cell voltage to obtain the second power. Wherein, when the first mapping table includes the maximum cell voltage, the first preset remaining power corresponding to the open circuit voltage that is the same as the maximum cell voltage in the first mapping table is determined as the first power; when the first mapping table does not include the maximum cell voltage, the first power is determined according to the voltage value and the difference algorithm in the first mapping table. Similarly, when the first mapping table includes the minimum cell voltage, the first preset remaining power corresponding to the open circuit voltage that is the same as the minimum cell voltage in the first mapping table is determined as the second power; when the first mapping table does not include the minimum cell voltage, the second power is determined according to the voltage value and the difference algorithm in the first mapping table.

[0117] S219: Query the second mapping relationship according to the extreme value of electricity to obtain the target SOC; wherein the extreme value of electricity includes the first electricity and the second electricity, and the second mapping relationship includes multiple preset extreme values ​​of electricity and multiple preset extreme values ​​of electricity each corresponding to the second preset remaining electricity. In addition, according to the average value method, the average value of the first electricity and the second electricity is used as the target SOC, the target SOC = (first electricity + second electricity) / 2, and then the current SOC is corrected to the target SOC. According to the weighted average value method, the first electricity and the second electricity are weighted averaged to obtain the target SOC, that is, the target SOC = w1 × first electricity + w2 × second electricity, and then the current SOC is corrected to the target SOC. Among them, w1 is the weight corresponding to the maximum cell voltage, w2 is the weight corresponding to the minimum cell voltage, w1 + w2 = 1.

[0118] S220: Correct the current SOC of the battery pack to the target SOC, that is, current SOC correction = target SOC.

[0119] S221: Control the switch module between the battery pack and the vehicle load to disconnect, so as to disconnect the battery pack from the vehicle load and realize the real power-off control of the vehicle.

[0120] S222: Exit the SOC correction process. At this point, the current SOC correction of the battery pack is completed.

[0121] The battery power correction method provided in the embodiment of the present application has the following technical effects:

[0122] 1. Actively correct the SOC of the battery pack, that is, no longer rely solely on the calibration opportunities that occur accidentally during the use of the vehicle, but actively create calibration conditions through a certain mechanism to ensure that the accuracy of the battery pack's SOC can be maintained even under adverse conditions.

[0123] 2. Improve the accuracy of SOC estimation. Discharging with a small current during the depolarization period of the battery pack can reduce the polarization effect inside the battery pack, so that the open circuit voltage can more truly reflect the state of the battery pack, thereby improving the accuracy of the SOC estimation of the battery pack.

[0124] 3. Reduce error accumulation. Long-term non-calibration will lead to accumulation of SOC estimation errors. The active calibration strategy can correct the error before it accumulates to a certain extent, which can prevent excessive SOC deviation from affecting user experience and battery life.

[0125] 4. Optimize the user's car experience. Users no longer need to worry about inaccurate SOC display caused by failure to meet calibration conditions for a long time. It increases the user's trust in the status of the vehicle's battery pack and makes it easier for users to accurately estimate the vehicle's pure electric range through the SOC displayed on the vehicle's dashboard.

[0126] The following are device embodiments of the present application, which can be used to execute the method embodiments of the present application. For details not disclosed in the device embodiments of the present application, please refer to the method embodiments of the present application.

[0127] Figure 4 A schematic diagram of the structure of a battery power correction device provided in an embodiment of the present application is shown. Figure 4 As shown, the battery power correction device 400 includes:

[0128] An event determination module 410, for determining whether a power-off event of the vehicle is triggered when a correction condition of the remaining power of the battery pack is met;

[0129] A battery control module 420, configured to perform a depolarization operation of the battery pack when the power-off event is triggered;

[0130] A voltage acquisition module 430, configured to acquire a voltage extreme value of the voltages of all the single cells of the battery pack when the depolarization of the battery pack is completed;

[0131] The power correction module 440 is used to correct the remaining power of the battery pack according to the voltage extreme value.

[0132] In a possible implementation, the voltage extremes include a maximum cell voltage and a minimum cell voltage, and the power correction module 440 includes:

[0133] A first query unit, configured to query a first mapping table of an open circuit voltage and a first preset remaining power according to the maximum cell voltage to obtain a first power;

[0134] A second query unit, configured to query the first mapping table according to the minimum cell voltage to obtain a second power;

[0135] A correction unit is used to correct the remaining power of the battery pack according to the first power and the second power.

[0136] In one possible implementation, the correction unit is specifically used to query a second mapping relationship based on the extreme value power to obtain a target remaining power; wherein the extreme value power includes the first power and the second power, the second mapping relationship includes multiple preset extreme value power and the multiple preset extreme value power each corresponds to a second preset remaining power; and the remaining power of the battery pack is corrected to the target remaining power.

[0137] In one possible implementation, the first query unit is specifically used to determine the first preset remaining power corresponding to the open-circuit voltage that is the same as the maximum cell voltage in the first mapping table as the first power when the first mapping table includes the maximum cell voltage; and to determine the first power based on the voltage value and difference algorithm in the first mapping table when the first mapping table does not include the maximum cell voltage.

[0138] In a possible implementation, the battery power correction device 400 includes:

[0139] A device control unit, configured to maintain the connection between the battery pack and the vehicle load before the battery control module 420 performs a depolarization operation of the battery pack;

[0140] The device control unit is further configured to disconnect the battery pack from the vehicle load after the power correction module 440 corrects the remaining power of the battery pack according to the voltage extreme value.

[0141] In a possible implementation, the battery power correction device 400 includes:

[0142] A polarization judgment unit is used to obtain the cumulative discharge amount of the battery pack while maintaining the connection between the battery pack and the vehicle load; when the cumulative discharge amount is greater than or equal to a first threshold, determine that the depolarization of the battery pack is completed.

[0143] In one possible implementation, the event judgment module 410 is also used to obtain the cumulative charge and discharge amount of the battery pack; when the cumulative charge and discharge amount is greater than the second threshold, determine whether the difference between the remaining power of the battery pack at any adjacent time is less than or equal to a third threshold; if so, determine that the correction condition is met; if not, determine that the correction condition is not met.

[0144] It should be noted that the battery power correction device provided in the above embodiment only uses the division of the above functional modules as an example when executing the battery power correction method. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the battery power correction device provided in the above embodiment and the battery power correction method embodiment belong to the same concept. Therefore, for details not disclosed in the device embodiment of the present application, please refer to the above-mentioned battery power correction method embodiment of the present application, which will not be repeated here.

[0145] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0146] Figure 5 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application is shown. Figure 5 As shown, the vehicle 500 includes: a memory 501 and a processor 502, wherein the memory 501 stores an executable program code 5011, and the processor 502 is used to call and execute the executable program code 5011 to perform a battery power correction method.

[0147] In this embodiment, the functional modules of the vehicle can be divided according to the above method example. For example, each functional module can be corresponded, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware. It should be noted that the division of modules in this embodiment is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0148] In the case of dividing each functional module according to each function, the vehicle may include: an event determination module, a battery control module, a voltage acquisition module, a power correction module, etc. It should be noted that all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module, which will not be repeated here.

[0149] The vehicle provided in this embodiment is used to execute the above-mentioned battery power correction method, and thus can achieve the same effect as the above-mentioned implementation method.

[0150] In the case of an integrated unit, the vehicle may include a processing module and a storage module. The processing module may be used to control and manage the actions of the vehicle. The storage module may be used to support the vehicle in executing relevant program codes and data.

[0151] The processing module may be a processor or a controller, which may implement or execute various exemplary logic blocks, modules and circuits described in conjunction with the disclosure of the present application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module may be a memory.

[0152] This embodiment also provides a computer-readable storage medium, in which a computer program code is stored. When the computer program code is executed on a computer, the computer executes the above-mentioned related method steps to implement a battery power correction method in the above-mentioned embodiment.

[0153] This embodiment further provides a computer program product. When the computer program product is run on a computer, the computer is caused to execute the above-mentioned related steps to implement a battery power correction method in the above-mentioned embodiment.

[0154] In addition, the vehicle provided in the embodiments of the present application may specifically be a chip, component or module, and the vehicle may include a connected processor and memory; wherein the memory is used to store instructions, and when the vehicle is running, the processor may call and execute instructions so that the chip executes a battery charge correction method in the above-mentioned embodiment.

[0155] Among them, the vehicle, computer-readable storage medium, computer program product or chip provided in this embodiment are all used to execute the corresponding battery power correction method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding battery power correction method provided above, and will not be repeated here.

[0156] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0157] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0158] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A battery power correction method, characterized in that: The battery charge correction method comprises: When the correction condition of the remaining power of the battery pack is met, determining whether a power-off event of the vehicle is triggered; If yes, performing a depolarization operation of the battery pack; When the depolarization of the battery pack is completed, obtaining the voltage extreme value of the voltages of all the single cells of the battery pack; The remaining power of the battery pack is corrected according to the voltage extreme value.

2. The battery charge correction method according to claim 1, characterized in that: The voltage extreme value includes a maximum cell voltage and a minimum cell voltage, and the correcting the remaining power of the battery pack according to the voltage extreme value includes: According to the maximum cell voltage, query a first mapping table of open circuit voltage and first preset remaining power to obtain a first power; According to the minimum cell voltage, query the first mapping table to obtain a second power; The remaining power of the battery pack is corrected according to the first power and the second power.

3. The battery charge correction method according to claim 2, characterized in that: The correcting the remaining power of the battery pack according to the first power and the second power includes: Querying a second mapping relationship according to the extreme value power to obtain a target remaining power; wherein the extreme value power includes the first power and the second power, and the second mapping relationship includes a plurality of preset extreme value power and each of the plurality of preset extreme value power corresponds to a second preset remaining power; The remaining power of the battery pack is corrected to the target remaining power.

4. The battery charge correction method according to claim 1, characterized in that: The step of querying a first mapping table of an open circuit voltage and a first preset remaining power according to the maximum cell voltage to obtain the first power includes: In the case where the first mapping table includes the maximum cell voltage, determining a first preset remaining power corresponding to an open circuit voltage that is the same as the maximum cell voltage in the first mapping table as the first power; In the case that the first mapping table does not include the maximum cell voltage, the first electrical quantity is determined according to voltage values ​​in the first mapping table and a difference algorithm.

5. The battery charge correction method according to any one of claims 1 to 4, characterized in that: Before performing the depolarization operation of the battery pack, the battery power correction method further includes: Maintaining the connection between the battery pack and the vehicle load; After correcting the remaining power of the battery pack according to the voltage extreme value, the battery power correction method further includes: The battery pack is disconnected from the vehicle load.

6. The battery charge correction method according to claim 5, characterized in that: The battery power correction method also includes: Under the condition of maintaining the connection between the battery pack and the vehicle load, obtaining the accumulated discharge amount of the battery pack; When the accumulated discharge amount is greater than or equal to a first threshold, it is determined that the depolarization of the battery pack is completed.

7. The battery charge correction method according to any one of claims 1 to 4, characterized in that: When the correction condition of the remaining power of the battery pack is met, before determining whether the power-off event of the vehicle is triggered, the battery power correction method further includes: Obtaining the cumulative charge and discharge amount of the battery pack; When the accumulated charge and discharge amount is greater than the second threshold, determining whether the difference between the remaining power of the battery pack at any adjacent time is less than or equal to a third threshold; If so, determining that the correction condition is satisfied; If not, it is determined that the correction condition is not satisfied.

8. A battery charge correction device, characterized in that: The battery charge correction device comprises: An event determination module, used to determine whether a power-off event of the vehicle is triggered when a correction condition of the remaining power of the battery pack is met; A battery control module, configured to perform a depolarization operation of the battery pack when the power-off event is triggered; A voltage acquisition module, used for acquiring the voltage extreme value of all the single cells of the battery pack when the depolarization of the battery pack is completed; A power correction module is used to correct the remaining power of the battery pack according to the voltage extreme value.

9. A vehicle, characterized in that: The vehicle comprises: A memory for storing executable program codes; A processor is used to call and run the executable program code from the memory, so that the vehicle executes the battery power correction method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed, the battery power correction method according to any one of claims 1 to 7 is implemented.

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