Remaining charge correction method and energy storage device

Abstract

Embodiments of the present application provide a remaining power correction method and an energy storage device. The method comprises: obtaining a battery pack voltage of a battery pack when a charging and discharging state, a battery pack temperature, a battery pack throughput change amount and a battery pack current all meet first preset correction requirements; obtaining a capacity increment corresponding to each time of voltage drop of the battery pack when a drop amplitude of the battery pack voltage is greater than a preset voltage threshold and a drop frequency exceeds a preset frequency, and selecting a minimum capacity increment; determining a target battery pack voltage corresponding to the minimum capacity increment; obtaining a current battery pack temperature and a current battery pack current corresponding to the battery pack when a plurality of capacity increments, the minimum capacity increment and the target battery pack voltage all meet second preset correction requirements, and determining a remaining power offset value according to the current battery pack temperature and the current battery pack current; and correcting a current remaining power of the battery pack according to the remaining power offset value. The above method can improve the accuracy of the remaining power display.

Description

Technical Field

[0001] This application belongs to the field of energy storage technology, and in particular relates to a method for correcting residual power and an energy storage device. Background Technology

[0002] Battery packs are widely used in various devices, especially energy storage devices. To measure the remaining power of an energy storage device, related technologies typically sample the open-circuit voltage of the device, calculate the change in remaining power based on the open-circuit voltage, and update the remaining power.

[0003] However, for lithium iron phosphate battery packs, the change trend between open-circuit voltage and remaining capacity is relatively gradual. If the open-circuit voltage is used to determine the remaining capacity of the battery pack, the calculated remaining capacity will deviate significantly from the actual remaining capacity, making it impossible for users to obtain accurate remaining capacity, which in turn affects the normal use of energy storage devices. Summary of the Invention

[0004] This application provides a method for correcting remaining power, an energy storage device, and a storage medium to solve the problem of inaccurate remaining power display.

[0005] The first aspect of this application provides a method for correcting remaining battery capacity, applied to an energy storage device. The energy storage device includes a battery pack. The method includes: acquiring the charge / discharge state of the battery pack, battery pack temperature, battery pack throughput change, and battery pack current; when the charge / discharge state, battery pack temperature, battery pack throughput change, and battery pack current all meet a first preset correction requirement, acquiring the battery pack voltage; when the detected decrease in battery pack voltage is greater than a preset voltage threshold and the number of decreases exceeds a preset number, acquiring the capacity increment corresponding to each decrease in battery pack voltage, and selecting the smallest capacity increment from multiple capacity increments; determining the target battery pack voltage corresponding to the smallest capacity increment; when multiple capacity increments, the smallest capacity increment, and the target battery pack voltage all meet a second preset correction requirement, acquiring the current battery pack temperature and current battery pack current corresponding to the battery pack, and determining a remaining battery capacity offset value based on the current battery pack temperature and current battery pack current; and correcting the current remaining battery capacity of the battery pack based on the remaining battery capacity offset value.

[0006] In this embodiment, if the charging / discharging state of the battery pack, battery pack temperature, battery pack throughput change, and battery pack current all meet the first preset correction requirements, then the battery pack voltage is determined. If the detected drop in battery pack voltage is greater than a preset voltage threshold and the number of drops exceeds a preset number, then the capacity increment corresponding to each drop in battery pack voltage is determined, and the smallest capacity increment is selected from multiple capacity increments. The target battery pack voltage corresponding to the smallest capacity increment is determined. If multiple capacity increments, the smallest capacity increment, and the target battery pack voltage all meet the second preset correction requirements, then the current battery pack temperature and current battery pack current are determined, and the remaining charge offset value is determined based on the current battery pack temperature and current battery pack current. The current remaining charge of the battery pack is corrected based on the remaining charge offset value. The above method identifies the boundaries of multiple flat areas of remaining power corresponding to the battery pack by monitoring the voltage drop of the battery pack to be greater than a preset voltage threshold and the number of drops to be greater than a preset number. By identifying the boundaries between the multiple flat areas of remaining power corresponding to the battery pack, the remaining power of the flat areas of the battery pack is corrected. This avoids the problem of the calculated remaining power deviating significantly from the actual remaining power when using open-circuit voltage to correct lithium iron phosphate battery packs, thus improving the accuracy of the remaining power display.

[0007] A second aspect of this application also provides a remaining power correction device applied to an energy storage device, the energy storage device including a battery pack. The remaining power correction device includes: a battery pack information acquisition module, used to acquire the charging and discharging state of the battery pack, battery pack temperature, battery pack throughput change, and battery pack current; a correction requirement judgment module, used to acquire the battery pack voltage when the charging and discharging state, battery pack temperature, battery pack throughput change, and battery pack current all meet a first preset correction requirement; a capacity increment acquisition module, used to acquire the capacity increment corresponding to each drop in the battery pack voltage when the detected drop in battery pack voltage is greater than a preset voltage threshold and the number of drops exceeds a preset number, and select the minimum capacity increment from multiple capacity increments; a battery pack voltage determination module, used to determine the target battery pack voltage corresponding to the minimum capacity increment; a power offset determination module, used to acquire the current battery pack temperature and current battery pack current corresponding to the battery pack when multiple capacity increments, the minimum capacity increment, and the target battery pack voltage all meet the second preset correction requirement, and determine the remaining power offset value based on the current battery pack temperature and current battery pack current; and a remaining power correction module, used to correct the current remaining power of the battery pack based on the remaining power offset value.

[0008] A third aspect of this application also provides an energy storage device, which includes a battery pack, a processor, and a memory. The processor is used to execute a computer program stored in the memory to implement the remaining power correction method described above.

[0009] A fourth aspect of this application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the remaining power correction method described above. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the open-circuit voltage curve of a lithium iron phosphate battery pack provided in an embodiment of this application;

[0012] Figure 2 A schematic diagram illustrating the remaining capacity error of a lithium iron phosphate battery pack under repeated charging and discharging cycles, as provided in an embodiment of this application.

[0013] Figure 3 A device diagram illustrating the remaining power correction method provided in the embodiments of this application;

[0014] Figure 4 This is a flowchart illustrating the remaining battery power correction method provided in an embodiment of this application;

[0015] Figure 5 This is a schematic diagram of the process for obtaining the battery pack throughput change provided in an embodiment of this application;

[0016] Figure 6A This is a schematic diagram of the open-circuit voltage curve under charging conditions provided in an embodiment of this application;

[0017] Figure 6B This is a schematic diagram of the open-circuit voltage curve under low-temperature conditions provided in the embodiments of this application;

[0018] Figure 7 This is a schematic diagram of the process for obtaining capacity increments provided in an embodiment of this application;

[0019] Figure 8A The capacity increment change curve provided in the embodiments of this application;

[0020] Figure 8B This is a graph showing the voltage variation of the battery pack provided in an embodiment of this application.

[0021] Figure 9 This is a schematic diagram of the process for determining the target voltage range provided in an embodiment of this application;

[0022] Figure 10This is a schematic diagram illustrating the process for determining the remaining battery power offset value provided in an embodiment of this application;

[0023] Figure 11 This is a schematic diagram of the process for correcting the current remaining battery power provided in an embodiment of this application;

[0024] Figure 12A This is an illustration of the effect of correcting the remaining power in a flat area according to the first embodiment of this application;

[0025] Figure 12B This is an uncorrected rendering of the remaining battery power in a flat area provided in the first embodiment of this application.

[0026] Figure 13A This is an illustration of the effect of correcting the remaining power in a flat area according to the second embodiment of this application;

[0027] Figure 13B This is an uncorrected rendering of the remaining battery power in a flat area provided in the second embodiment of this application;

[0028] Figure 14 This is a schematic diagram of the remaining power correction device provided in the embodiments of this application. Detailed Implementation

[0029] To better understand the above-mentioned objectives, features, and advantages of this application, the application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0030] Numerous specific details are set forth in the following description in order to provide a full understanding of this application. The described embodiments are only some, not all, of the embodiments of this application.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0032] Battery packs currently have a wide range of applications, including various devices. For example, they can be used in self-moving devices such as automotive equipment, lawnmowers, sweepers, mine-clearing equipment, and cruise control devices; they can also be used in energy storage devices such as mobile energy storage devices and home energy storage devices; or other electronic devices that require battery packs—there are no limitations on this. Battery packs can also be used independently in conjunction with other devices, such as power conversion equipment and photovoltaic modules—there are no further limitations on this either.

[0033] This application uses a battery pack applied to an energy storage device as an example. To measure the remaining capacity of an energy storage device, related technologies typically use the ampere-hour integration method or the Kalman filter method to estimate the remaining capacity. Both of these methods sample the open-circuit voltage of the energy storage device, calculate the change in remaining capacity based on the open-circuit voltage, and update the remaining capacity accordingly.

[0034] However, for lithium iron phosphate battery packs, the trend between open-circuit voltage and remaining capacity is relatively gradual. (See [reference needed]) Figure 1 , Figure 1 This is a schematic diagram of the open-circuit voltage curve of a lithium iron phosphate battery pack provided in an embodiment of this application. The horizontal axis represents the remaining capacity, and the vertical axis represents the open-circuit voltage. In one embodiment, the remaining capacity of the energy storage device is expressed as a percentage, such as 90%, 80%, 70%, etc.; in other embodiments, the remaining capacity of the energy storage device is expressed as a numerical value, such as 90%, 80%, 70%, etc. This embodiment of the application uses the remaining capacity expressed as a percentage as an example, such as... Figure 1 As shown, 3.29V corresponds to a remaining capacity range of 30%-55%, and 3.33V corresponds to a remaining capacity range of 65%-100%. When the remaining capacity range is 30%-55%, the open-circuit voltage change is relatively flat. This 30%-55% remaining capacity range is considered a flat open-circuit voltage region (also simplified as a flat region in this embodiment). Similarly, the 65%-100% remaining capacity range is also called a flat region. Therefore, it is impossible to use the open-circuit voltage to correct for the remaining capacity in these two flat regions. If the open-circuit voltage is used to determine the remaining capacity of the battery pack in these two flat regions, the calculated remaining capacity will deviate significantly from the actual remaining capacity, making it impossible for users to obtain accurate remaining capacity, thus affecting the normal use of the energy storage device. See also... Figure 2 , Figure 2 This diagram illustrates the remaining capacity error of a lithium iron phosphate battery pack under repeated charge and discharge cycles, as provided in this application embodiment. The horizontal axis represents time, and the vertical axis represents the remaining capacity. The lithium iron phosphate battery pack is repeatedly charged and discharged within the remaining capacity range of 30%-80%. The first curve represents the change in remaining capacity estimated using open-circuit voltage, the second curve represents the change in actual remaining capacity, and the third curve represents the error between the remaining capacity estimated using open-circuit voltage and the actual remaining capacity of the battery pack. Figure 2 As shown, the error between the remaining power estimated using open-circuit voltage and the actual remaining power of the battery pack is getting larger and larger.

[0035] In view of the above problems, this application provides a remaining power correction method, which solves the problem that the calculated remaining power deviates significantly from the actual remaining power when using open-circuit voltage to correct lithium iron phosphate battery packs in the traditional technology, thereby improving the accuracy of remaining power display.

[0036] Combination Figure 3A device diagram illustrating the remaining power correction method provided in the embodiments of this application is shown. For example... Figure 3 As shown, the energy storage device 30 includes a memory 31, at least one controller 32, at least one communication bus 33, and a battery pack 34.

[0037] Figure 3 The illustrated structure of the energy storage device does not constitute a limitation on the embodiments of this application. The energy storage device 30 may also include more or fewer other hardware or software, or different component arrangements than those shown in the figure. For example, the energy storage device 30 may also include multiple interfaces. For example, a first interface is used to connect a load to supply power to the load, and a second interface is used to connect an independent battery pack to increase the capacity of the energy storage device.

[0038] In one embodiment of this application, the energy storage device 30 can be a self-moving device including a battery pack, such as an automotive device, lawnmower, sweeper, or cruiser; it can also be a mobile energy storage device, a home energy storage device, or other electronic devices including a battery pack or equipped with energy storage functions. The energy storage device 30 can also be connected to a client device, which includes, but is not limited to, any electronic product that allows human-computer interaction with the user via a keyboard, mouse, remote control, touchpad, or voice control device, such as a personal computer, tablet computer, smartphone, or digital camera.

[0039] It should be noted that the energy storage device 30 is only an example. Other existing or future electronic products that are applicable to this application should also be included within the scope of protection of this application and are incorporated herein by reference.

[0040] In some embodiments, at least one communication bus 33 is configured to enable communication between the memory 31 and at least one controller 32, etc.

[0041] In some embodiments, the energy storage device 30 may further include a battery pack 34 that powers the various components. The battery pack 34 may be logically connected to at least one controller 32 via a power management device (not shown), thereby enabling the power management device to manage functions such as charging, discharging, and power consumption. The energy storage device 30 may also include one or more DC or AC power supplies, recharging devices, power fault detection circuits, power converters or inverters, power status indicators, and other arbitrary components. The energy storage device 30 may also include various sensors, Bluetooth modules, Wi-Fi modules, etc., which will not be described in detail here.

[0042] Figure 4 This is a flowchart illustrating the remaining power correction method provided in an embodiment of this application. The remaining power correction method can be applied to energy storage devices. Figure 4As shown, the remaining battery power correction method may include the following steps. Depending on different needs, the order of the steps in this flowchart may be changed, and some may be omitted.

[0043] S11, acquire the charge / discharge status of the battery pack, battery pack temperature, battery pack throughput change, and battery pack current.

[0044] In one embodiment, the charge / discharge state of the battery pack includes a charging state and a discharging state, wherein the charging state indicates that the battery pack is undergoing a charging process, and the discharging state indicates that the battery pack is undergoing a discharging process. The charge / discharge state can be determined based on the magnitude of the charging / discharging current in the charge / discharge circuit of the battery pack. For example, the current range of the battery pack when it is at rest can be determined, such as -1A < I < 1A. When the detected current is outside this range, it can be determined that the battery pack is in a charging or discharging state. Taking the current flow direction during charging as positive, if the detected current flowing through the charge / discharge circuit of the battery pack is greater than or equal to 1A, it indicates that the battery pack is in a charging state. If the detected current flowing through the charge / discharge circuit of the battery pack is less than or equal to -1A, it indicates that the battery pack is in a discharging state.

[0045] In one embodiment, the battery pack temperature can be monitored by a temperature sensor. For example, a temperature sensor can be installed on the surface of each battery cell in the battery pack to monitor the temperature value of each battery cell. In one embodiment, the battery pack temperature can be characterized by the temperature value corresponding to the battery cell with the highest temperature in the battery pack. In other embodiments, the battery pack temperature can also be characterized by the temperature value corresponding to the battery cell with the lowest temperature in the battery pack.

[0046] In one embodiment, the change in battery pack throughput can refer to the change in the current battery pack throughput compared to the battery pack throughput at the previous correction time. The previous correction time refers to the moment when the current remaining battery capacity of the battery pack was last corrected using the remaining capacity correction method provided in this application embodiment. Battery pack throughput refers to the total charging and discharging capacity of the battery pack, that is, the sum of the stored and released capacity of the battery pack. Battery pack throughput is used to indicate the cumulative error of the remaining battery capacity; the higher the battery pack throughput, the larger the cumulative error of the remaining battery capacity; the lower the battery pack throughput, the smaller the cumulative error of the remaining battery capacity.

[0047] In one embodiment, the battery pack current refers to the current after the discharge current of the battery pack has been denoised. For example, the discharge current of the battery pack is collected and transmitted to a first-order low-pass filter to remove high-frequency noise in the discharge current, thereby obtaining the battery pack current.

[0048] S12: When the charging / discharging state, battery pack temperature, battery pack throughput change and battery pack current all meet the first preset correction requirements, the battery pack voltage is obtained.

[0049] In one embodiment, the first preset correction requirement refers to the requirement of correcting the remaining power in a flat area of ​​the battery pack. The first preset correction requirement may include charge / discharge state requirements, battery pack temperature requirements, battery pack throughput change requirements, and battery pack current requirements. Timing begins when the battery pack's charge / discharge state meets the requirements, the battery pack temperature meets the requirements, the battery pack throughput change meets the requirements, and the battery pack current meets the requirements. When the timing reaches a preset duration, it is determined that the battery pack meets the first preset correction requirement. If any of the above requirements are not met, timing stops, and it is determined that the battery pack does not meet the first preset correction requirement. The preset duration can be set according to actual needs; for example, the preset duration can be 1 hour. Timing for 1 hour allows the internal polarization reaction of the battery pack to stabilize, avoiding voltage changes caused by the polarization reaction and improving the accuracy of the remaining power display. In one embodiment, the battery pack voltage refers to the voltage after the discharge voltage of the battery pack has been denoised. For example, the discharge voltage of the battery pack is collected and transmitted to a first-order low-pass filter to remove high-frequency noise in the discharge voltage, thereby obtaining the battery pack voltage.

[0050] S13, when the voltage drop of the battery pack is detected to be greater than the preset voltage threshold and the number of drops exceeds the preset number, the capacity increment corresponding to each drop of the battery pack is obtained, and the minimum capacity increment is selected from multiple capacity increments.

[0051] In one embodiment, the preset voltage threshold and preset number of drops are set according to actual needs. For example, the preset voltage threshold can be 5mV, and the preset number of drops can be 3. A drop count exceeding the preset number of drops means the drop count is greater than or equal to the preset number of drops. The capacity increment is related to the corresponding capacity change and voltage change value of the battery pack.

[0052] For example, when the voltage drop of the battery pack is detected to be greater than the preset voltage threshold for the first time, the battery pack voltage A1, capacity increment B1, and current remaining charge C1 are recorded, and the current drop count is recorded as 1. When the voltage drop of the battery pack is detected to be greater than the preset voltage threshold for the second time, the battery pack voltage A2, capacity increment B2, and current remaining charge C2 are recorded, and the current drop count is recorded as 2. When the voltage drop of the battery pack is detected to be greater than the preset voltage threshold for the third time, the battery pack voltage A3, capacity increment B3, and current remaining charge C3 are recorded, and the current drop count is recorded as 3. At this point, the drop count is 3, which exceeds the preset count. Then, the minimum value among capacity increments B1, B2, and B3 is selected as the minimum capacity increment.

[0053] S14, determine the target battery pack voltage corresponding to the minimum capacity increment.

[0054] In one embodiment, following the above embodiments, at any given time, there exists a correspondence between battery pack voltage and capacity increment. For example, battery pack voltage A1 corresponds to capacity increment B1, battery pack voltage A2 corresponds to capacity increment B2, and battery pack voltage A3 corresponds to capacity increment B3. By querying the above correspondence, the target battery pack voltage corresponding to the minimum capacity increment can be obtained.

[0055] S15, when multiple capacity increments, minimum capacity increments and target battery pack voltage all meet the second preset correction requirements, obtain the current battery pack temperature and current battery pack current corresponding to the battery pack, and determine the remaining power offset value based on the current battery pack temperature and current battery pack current.

[0056] In one embodiment, the second preset correction requirement refers to the requirement to correct the remaining capacity in a flat area of ​​the battery pack. The second preset correction requirement may include a capacity increment requirement, a minimum capacity increment requirement, and a target battery pack voltage requirement. When multiple capacity increments meet the capacity increment requirements, the minimum capacity increment meets the minimum capacity increment requirement, and the target battery pack voltage meets the target battery pack voltage requirement, the battery pack is determined to meet the second preset correction requirement; when any of the above requirements are not met, the battery pack is determined not to meet the second preset correction requirement.

[0057] In one embodiment, following the above embodiment, the battery pack includes two flat regions. These two flat regions are divided into a high-flat region and a low-flat region based on the magnitude of the open-circuit voltage corresponding to each flat region. The open-circuit voltage corresponding to the high-flat region is greater than that corresponding to the low-flat region. For example, the open-circuit voltage corresponding to the 30%-55% remaining charge range is 3.29V, and the open-circuit voltage corresponding to the 65%-100% remaining charge range is 3.33V. Thus, the 30%-55% remaining charge range is the low-flat region, and the 65%-100% remaining charge range is the high-flat region. In one embodiment, there is a transition boundary between the high-flat region and the low-flat region. The remaining charge at this boundary (also simplified as "first remaining charge" in this embodiment) corresponds to the current battery pack temperature and current battery pack current. By obtaining the current battery pack temperature and current battery pack current, and querying this correspondence based on the current battery pack temperature and current battery pack current, the first remaining charge can be obtained. For example, when the current battery pack temperature is 10 degrees Celsius and the current battery pack current is 0.05C (0.05C means the current value is 0.05 times the battery pack capacity; "C" is the discharge rate of the battery pack, used to identify the discharge capacity of the battery pack. For example, when the battery pack capacity is 100Ah, the discharge current at 0.05C is 5A), the corresponding first remaining charge is 62%; when the current battery pack temperature is 10 degrees Celsius and the current battery pack current is 0.1C, the corresponding first remaining charge is 65%.

[0058] In one embodiment, following the above embodiments, at the same time, there is a correspondence between the capacity increment and the current remaining power. For example, capacity increment B1 corresponds to the current remaining power C1, capacity increment B2 corresponds to the current remaining power C2, and capacity increment B3 corresponds to the current remaining power C3. By querying the above correspondence, the current remaining power corresponding to the smallest capacity increment (also simplified as "second remaining power" in this embodiment) can be obtained.

[0059] In one embodiment, the remaining power offset value refers to the power value used to correct the current remaining power of the battery pack. The remaining power offset value is obtained by calculating the difference between the first remaining power and the second remaining power.

[0060] S16, correct the current remaining power of the battery pack based on the remaining power offset value.

[0061] In one embodiment, the corrected remaining power is denoted as the target remaining power, and the target remaining power is obtained using the following formula 1:

[0062] Formula 1: Target remaining battery power = Current remaining battery power - Remaining battery power offset value.

[0063] The remaining power correction method provided in this application identifies the boundaries of multiple flat areas of remaining power corresponding to the battery pack by monitoring the battery pack voltage drop to be greater than a preset voltage threshold and the number of drops to be greater than a preset number. By identifying the boundaries between the multiple flat areas of remaining power corresponding to the battery pack, the remaining power of the flat areas corresponding to the battery pack is corrected. This avoids the problem of the calculated remaining power deviating significantly from the actual remaining power due to the use of open-circuit voltage to correct lithium iron phosphate battery packs, and improves the accuracy of remaining power display.

[0064] In one embodiment, the battery pack throughput is used to identify the cumulative error of the remaining battery capacity. The higher the battery pack throughput, the larger the cumulative error of the remaining battery capacity; the lower the battery pack throughput, the smaller the cumulative error of the remaining battery capacity. Figure 5 This is a schematic diagram illustrating the process of obtaining changes in battery pack throughput provided in an embodiment of this application. The method for obtaining changes in battery pack throughput is applied to energy storage devices. Figure 5 As shown, it includes the following steps:

[0065] S21, obtain the current battery pack throughput and the battery pack throughput at the previous correction time.

[0066] In one embodiment, the current battery pack throughput refers to the battery pack throughput at the current moment, and the previous correction moment refers to the moment when the current remaining battery pack capacity was last corrected using the remaining capacity correction method provided in this application embodiment.

[0067] S22, determine the change in battery pack throughput based on the current battery pack throughput and the battery pack throughput at the previous correction time.

[0068] In one embodiment, the battery pack throughput change refers to the change in the current battery pack throughput compared to the battery pack throughput at the previous correction time. The battery pack throughput change is obtained by numerically calculating the current battery pack throughput and the battery pack throughput at the previous correction time. In another embodiment, the battery pack throughput change is obtained by calculating the difference between the current battery pack throughput and the battery pack throughput at the previous correction time.

[0069] This application embodiment improves the accuracy of battery pack remaining power display by monitoring the change in battery pack throughput at the current moment and the change in battery pack throughput at the previous correction moment, and using the change in battery pack throughput as the correction condition for the remaining battery power.

[0070] In one embodiment, when the battery pack is in a discharging state and the battery pack temperature is greater than a preset temperature threshold, a remaining power correction method can be performed on the high-flat and low-flat regions. When the battery pack is in a charging state, or when the battery pack temperature is less than or equal to the preset temperature threshold, the boundary between the high-flat and low-flat regions of the battery pack is not obvious, and the remaining power correction method cannot be performed on the high-flat and low-flat regions. See also Figure 6A and 6B , Figure 6A This is a schematic diagram of the open-circuit voltage curve under charging conditions provided in an embodiment of this application. Figure 6B This is a schematic diagram of the open-circuit voltage curve at low temperature provided in an embodiment of this application. Figure 6B The low-temperature state shown can refer to a battery pack temperature below -10 degrees Celsius. Figure 6A The horizontal axis represents the remaining battery power, and the vertical axis represents the voltage. Figure 6B The horizontal axis represents the remaining battery power, and the vertical axis represents the voltage. Figure 6A and Figure 6B Each curve in the figure represents the open-circuit voltage curve corresponding to a specific battery pack model. Figure 6A and Figure 6B The open-circuit voltage curves of multiple battery packs show that the boundary between the high-flat region and the low-flat region is not very obvious.

[0071] In one embodiment, the charge / discharge state requirement may refer to the battery pack being in a discharge state; the battery pack temperature requirement may refer to the battery pack temperature being greater than a preset temperature threshold; the battery pack throughput change may refer to the battery pack throughput change being greater than a preset throughput change threshold; and the battery pack current requirement may refer to the battery pack current being within a preset current range and the current fluctuation range being less than a preset fluctuation threshold. Timing begins when the charge / discharge state is in a discharge state, the battery pack temperature is greater than the preset temperature threshold, the battery pack throughput change is greater than the preset throughput change threshold, and the battery pack current is within the preset current range and the current fluctuation range is less than the preset fluctuation threshold. When the timing duration reaches a preset duration, it is determined that the charge / discharge state, battery pack temperature, battery pack throughput change, and battery pack current all meet the first preset correction requirement. The preset temperature threshold, preset throughput change threshold, preset current range, preset fluctuation threshold, and preset duration can all be set according to actual needs. For example, the preset temperature threshold can be 10 degrees Celsius; the preset throughput change threshold can be 10*Q, where Q is the preset throughput value; the preset current range can be [500mA, 0.12C]; the preset fluctuation threshold can be 0.01C; and the preset duration is 1 hour. This embodiment monitors the range and fluctuation amplitude of the battery pack current to avoid battery pack voltage fluctuations caused by current fluctuations interfering with the acquisition of capacity increments, thus improving the accuracy of remaining power display. In one embodiment, in addition to the battery pack current causing battery pack voltage changes, the polarization reaction inside the battery pack also causes battery pack voltage changes. Therefore, a preset duration needs to be maintained under a stable current scenario (i.e., the battery pack current is within the range of 500mA to 0.12C, and the current fluctuation range is less than 0.01C) to stabilize the internal polarization reaction of the battery pack, further improving the accuracy of remaining power display.

[0072] Figure 7 This is a schematic diagram of the capacity increment acquisition process provided in an embodiment of this application. The capacity increment acquisition method is applied to energy storage devices. Figure 7 As shown, it includes the following steps:

[0073] S31, when the voltage drop of the battery pack is equal to the preset voltage threshold, determine the corresponding capacity change value and voltage change value of the battery pack.

[0074] In one embodiment, taking a preset voltage threshold of 5mV as an example, the voltage change value is 5mV. The capacity change value can refer to the capacity change corresponding to a 5mV change in battery pack voltage. The system obtains a first capacity value and a first battery pack voltage when the first detected drop in battery pack voltage equals 5mV. It also obtains a second battery pack voltage (plus 5mV) and a second capacity value corresponding to the second battery pack voltage. The difference between the first and second capacity values ​​is then used as the capacity change value.

[0075] S32, determine the capacity increment based on the capacity change value and the voltage change value.

[0076] In one embodiment, the capacity increment is related to the corresponding capacity change and voltage change of the battery pack. The capacity change is denoted as deltaQ, and the voltage change is denoted as deltaV. The capacity increment is determined using the following formula 2:

[0077] Formula 2: Capacity increment = deltaQ / deltaV.

[0078] This application embodiment monitors the capacity increment of the battery pack when the voltage drop equals a preset voltage threshold, and uses the capacity increment as a correction condition for the remaining battery power, thereby improving the accuracy of the remaining battery power display.

[0079] In one embodiment, the capacity increment requirement may refer to the capacity increment change trend corresponding to multiple capacity increments satisfying a preset capacity change trend; the minimum capacity increment requirement may refer to the minimum capacity increment being less than a target minimum capacity increment threshold; and the target battery pack voltage requirement may refer to the target battery pack voltage being within a target voltage range. When the capacity increment change trend corresponding to multiple capacity increments satisfies the preset capacity change trend, the minimum capacity increment is less than the target minimum capacity increment threshold, and the target battery pack voltage is within the target voltage range, then it is determined that the multiple capacity increments, the minimum capacity increment, and the target battery pack voltage all satisfy the second preset correction requirement.

[0080] In one embodiment, the preset capacity change trend can be set according to actual needs. For example, the preset capacity change trend can be a trend of capacity increment first decreasing and then increasing. Continuing with the above embodiment, the capacity increments B1, B2, and B3 are recorded in chronological order. When capacity increment B1 is greater than capacity increment B2, and capacity increment B3 is greater than capacity increment B2, it is determined that the capacity increment first decreases and then increases. This confirms that the capacity increment change trends corresponding to multiple capacity increments satisfy the preset capacity change trend. The target minimum capacity increment threshold corresponds to the current battery pack temperature and current battery pack current. Based on this correspondence, the target minimum capacity increment threshold can be obtained. (See also...) Figure 8A , Figure 8A The graph showing the capacity increment change provided in this application embodiment has the horizontal axis representing capacity over time and the vertical axis representing capacity increment. Figure 8A The arrow in the image indicates where the remaining battery power correction operation is triggered. For example... Figure 8A As shown in the arrow, the capacity increment shows a trend of first decreasing and then increasing, and the minimum capacity increment is less than the target minimum capacity increment threshold.

[0081] In one embodiment, the target voltage range can be defined as the open-circuit voltage corresponding to the high flat region (also simplified as "high flat region voltage" in this embodiment) and the open-circuit voltage corresponding to the low flat region (also simplified as "low flat region voltage" in this embodiment). Both the high flat region voltage and the low flat region voltage correspond to the current battery pack temperature and current battery pack current. Based on this correspondence, the high flat region voltage and the low flat region voltage can be obtained, and thus the target voltage range can be derived. See also... Figure 8B , Figure 8B The graph shows the voltage change of the battery pack provided in the embodiments of this application. The horizontal axis represents time, and the vertical axis represents the battery pack voltage. Figure 8B The arrow in the image indicates where the remaining battery power correction operation is triggered. For example... Figure 8B As shown in the image, the target battery pack voltage is within the target voltage range, as indicated by the arrow.

[0082] This application embodiment monitors the capacity increment change trends corresponding to multiple capacity increments to ensure they meet preset capacity change trends, the minimum capacity increment is less than the target minimum capacity increment threshold, and the target battery pack voltage is within the target voltage range. This allows for the rapid and accurate identification of the boundaries of multiple flat areas with remaining power corresponding to the battery pack. By identifying the boundaries between these flat areas, the remaining power in the flat areas corresponding to the battery pack can be corrected, thus improving the accuracy of the remaining power correction display.

[0083] Figure 9 This is a schematic diagram illustrating the process of determining the target voltage range provided in an embodiment of this application. The method for determining the target voltage range is applied to energy storage devices. Figure 9 As shown, it includes the following steps:

[0084] S41, obtain the current battery pack temperature and current battery pack current corresponding to the battery pack.

[0085] In one embodiment, the current battery pack temperature and current are obtained at the current moment.

[0086] S42, based on the pre-set correspondence between battery pack temperature and battery pack current relative to high flat zone voltage, low flat zone voltage and minimum capacity increment threshold, determine the target high flat zone voltage, target low flat zone voltage and target minimum capacity increment threshold corresponding to the current battery pack temperature and current battery pack current.

[0087] In one embodiment, a pre-set correspondence between battery pack temperature, battery pack current, and minimum capacity increment threshold is established. By querying this correspondence based on the current battery pack temperature and current battery pack current, the target minimum capacity increment threshold can be obtained. For example, when the current battery pack temperature is 10 degrees Celsius and the current battery pack current is 0.05C, the corresponding target minimum capacity increment threshold is 668; when the current battery pack temperature is 10 degrees Celsius and the current battery pack current is 0.1C, the corresponding minimum capacity increment threshold is 943.

[0088] In one embodiment, both the high flatness region voltage and the low flatness region voltage are correlated with the current battery pack temperature and current battery pack current. By querying the correlation between the current battery pack temperature and current current, the high flatness region voltage and the low flatness region voltage of the battery pack can be determined. For example, when the current battery pack temperature is 10 degrees Celsius and the current battery pack current is 0.05C, the corresponding high flatness region voltage is 3287 and the low flatness region voltage is 3263; when the current battery pack temperature is 10 degrees Celsius and the current battery pack current is 0.1C, the corresponding high flatness region voltage is 3270 and the low flatness region voltage is 3252.

[0089] S43, determine the target voltage range based on the target high flat region voltage and the target low flat region voltage.

[0090] In one embodiment, the target voltage range can be defined as the high flat region voltage and the low flat region voltage. Continuing with the above embodiment, when the high flat region voltage is 3287 and the low flat region voltage is 3263, the target voltage range is (3263, 3287); when the high flat region voltage is 3270 and the low flat region voltage is 3252, the target voltage range is (3252, 3270).

[0091] This application embodiment, by pre-setting the correspondence between battery pack temperature and battery pack current relative to high flat area voltage, low flat area voltage, and minimum capacity increment threshold, can quickly and accurately determine the minimum capacity increment threshold and target voltage range corresponding to the battery pack, thereby quickly and accurately identifying the boundaries of multiple remaining power flat areas corresponding to the battery pack, improving the accuracy and speed of remaining power display.

[0092] Figure 10 This is a schematic diagram illustrating the process for determining the remaining power offset value provided in an embodiment of this application. The method for determining the remaining power offset value is applied to energy storage devices. Figure 10 As shown, it includes the following steps:

[0093] S51, obtain the pre-set correspondence between the battery pack temperature and the remaining charge corresponding to the boundary of the relatively flat area of ​​the battery pack current.

[0094] In one embodiment, there is a transitional boundary between the high-flat region and the low-flat region, and the remaining charge at this boundary (also simply referred to as "first remaining charge" in this embodiment) corresponds to the current battery pack temperature and the current battery pack current.

[0095] S52, determine the first remaining charge at the boundary of the flat area corresponding to the battery pack based on the current battery pack temperature and current battery pack current.

[0096] In one embodiment, by obtaining the current battery pack temperature and current battery pack current, and querying the correspondence based on the current battery pack temperature and current battery pack current, the first remaining battery capacity can be obtained.

[0097] S53, obtain the second remaining power corresponding to the minimum capacity increment.

[0098] In one embodiment, following the above embodiments, there is a correspondence between the capacity increment and the current remaining power. For example, capacity increment B1 corresponds to the current remaining power C1, capacity increment B2 corresponds to the current remaining power C2, and capacity increment B3 corresponds to the current remaining power C3. Assuming the minimum capacity increment is capacity increment B2, by querying the above correspondence, the current remaining power corresponding to the minimum capacity increment B2 can be obtained as the current remaining power C2 (also simplified as "second remaining power" in this embodiment).

[0099] S54, determine the remaining power offset value based on the first remaining power and the second remaining power.

[0100] In one embodiment, the remaining battery power offset value is determined using the following formula 3:

[0101] Formula 3: Remaining power offset value = Second remaining power - First remaining power.

[0102] The embodiments of this application determine the remaining power offset value based on the first remaining power corresponding to the boundary between the high-flat region and the low-flat region and the second remaining power corresponding to the minimum capacity increment. This can avoid the problem that the calculated remaining power deviates significantly from the actual remaining power due to the use of open-circuit voltage to correct lithium iron phosphate battery packs, thereby improving the accuracy of the remaining power display.

[0103] In one embodiment, when the remaining power offset value is large, if the current remaining power of the battery pack is directly corrected based on the remaining power offset value, the remaining power of the battery pack will jump during the display process. Therefore, it is necessary to adjust the convergence speed of the remaining power to ensure that the current remaining power of the battery pack can smoothly converge to a certain range and improve the stability of the remaining power correction. Figure 11This is a schematic diagram of the process for correcting the current remaining power capacity provided in an embodiment of this application. The method for correcting the current remaining power capacity is applied to energy storage devices. Figure 11 As shown, it includes the following steps:

[0104] S61, obtain the change in the remaining power of the battery pack.

[0105] In one embodiment, the change in remaining power refers to the change in remaining power of the battery pack during a single operating cycle. A single operating cycle can refer to a complete process in which the battery pack first discharges from a first specified remaining power value to a second specified remaining power value, and then recharges back to the first specified remaining power value. The change in remaining power is the difference between the first specified remaining power value and the second specified remaining power value. The first specified remaining power value is not necessarily 100%, and can also be 80%; the second specified remaining power value is not necessarily 0%, and can also be 20% or 30%, without limitation. For example, when the first specified remaining power value is 80% and the second specified remaining power value is 30%, the change in remaining power is 50%; when the first specified remaining power value is 100% and the second specified remaining power value is 0%, the change in remaining power is 100%.

[0106] S62 determines the dynamic catch-up rate based on the current remaining power of the battery pack and the power offset value.

[0107] In one embodiment, the dynamic catch-up ratio refers to a value used to dynamically correct the current remaining capacity of the battery pack. The rate of change of the remaining capacity can be determined based on the dynamic catch-up ratio. The dynamic catch-up ratio is related to the current remaining capacity of the battery pack and the capacity offset value, and is determined using the following formula 4:

[0108] Formula 4: Dynamic catch-up ratio = 1 + k * (current remaining battery power - battery offset value) / battery offset value.

[0109] Where k is a pre-set coefficient.

[0110] S63 determines the single-cycle change value of the battery pack based on the change in remaining power and the dynamic catch-up rate.

[0111] In one embodiment, the product of the remaining power change and the dynamic catch-up ratio is calculated to obtain the single power change value of the battery pack.

[0112] S64 corrects the current remaining battery charge of the battery pack based on the single charge change value.

[0113] In one embodiment, the current remaining power is denoted as user SOC(t), and the current remaining power of the battery pack is determined using the following formula 5:

[0114] Formula 5: User SOC(t) = User SOC(t-1) + Single change in electricity consumption

[0115] Where t represents time, assuming a single change in battery level is 0.01%, after 100 operations to determine the current remaining battery level, the change in the current remaining battery level is 1%. On the application side, this can prevent the remaining battery level from jumping during the display process.

[0116] This application embodiment determines the single-time power change value of the battery pack by setting a dynamic catch-up ratio, and corrects the current remaining power of the battery pack based on the single-time power change value. This can avoid the remaining power from jumping during the display process, ensure that the current remaining power of the battery pack can smoothly converge to a certain range, and improve the stability of the remaining power correction.

[0117] In one embodiment, a real-world user scenario is simulated on the energy storage device. For example, the load devices connected to the energy storage device include a laptop and two monitors. The battery pack is charged to 85% capacity, and then the remaining capacity is set to 99%. See also Figure 12A and Figure 12B , Figure 12A This is an illustration showing the effect of correcting the remaining battery power in a flat area according to the first embodiment of this application. Figure 12B This is an uncorrected rendering of the remaining battery power in a flat area provided in the first embodiment of this application, as shown below. Figure 12A As shown, the horizontal axis represents time, and the vertical axis represents the remaining battery power. After identifying the boundary of the flat region, the remaining battery power is adjusted to 60%. The current remaining battery power (the wavy curve) decreases rapidly and then smoothly converges to a certain range; as shown... Figure 12B As shown, the horizontal axis represents time, and the vertical axis represents remaining battery power. When no remaining battery power adjustment is made in a flat region, the current remaining battery power decreases rapidly compared to... Figure 12A However, when adjusting for remaining power in a flat area, the remaining power curve is smoother.

[0118] In one embodiment, a real-world user scenario is simulated on the energy storage device. For example, the load devices connected to the energy storage device include a laptop and two monitors. The battery pack is charged to 100% capacity, and then the remaining capacity is set to 80%. See also Figure 13A and Figure 13B , Figure 13A This is an illustration showing the effect of correcting the remaining battery power in a flat area according to the second embodiment of this application. Figure 13B This is an uncorrected rendering of the remaining battery power in a flat area provided in the second embodiment of this application, as shown below. Figure 13AAs shown, the horizontal axis represents time, and the vertical axis represents the remaining battery power. After identifying the boundary of the flat region, the remaining battery power is adjusted to 60%, and the current remaining battery power (the wavy curve) decreases slowly, smoothly converging to a certain range; as shown... Figure 13B As shown, the horizontal axis represents time, and the vertical axis represents remaining battery power. When remaining battery power is not corrected in a flat region, the remaining battery power remains at 1% for too long, compared to... Figure 13A However, when adjusting for remaining power in a flat area, the remaining power curve is smoother.

[0119] Please see Figure 14 , Figure 14 This is a schematic diagram of the structure of the remaining power correction device provided in an embodiment of this application. In some embodiments, the remaining power correction device 20 may include multiple functional modules composed of computer program segments. The computer programs of each program segment in the remaining power correction device 20 may be stored in the memory of the energy storage device and executed by at least one processor to perform (see details). Figure 4 (Description) The power control function.

[0120] In this embodiment, the remaining power correction device 20 can be divided into multiple functional modules according to its functions. These functional modules may include: a battery pack information acquisition module 201, a correction requirement judgment module 202, a capacity increment acquisition module 203, a battery pack voltage determination module 204, a power offset determination module 205, and a remaining power correction module 206. The term "module" in this application refers to a series of computer program segments that can be executed by at least one processor and perform a fixed function, and which are stored in memory. In this embodiment, the functions of each module will be detailed in subsequent embodiments.

[0121] The battery pack information acquisition module 201 can be used to acquire the charging and discharging status of the battery pack, the battery pack temperature, the battery pack throughput change, and the battery pack current.

[0122] The correction requirement judgment module 202 can be used to obtain the battery pack voltage when the charging / discharging state, battery pack temperature, battery pack throughput change and battery pack current all meet the first preset correction requirement.

[0123] The capacity increment acquisition module 203 can be used to acquire the capacity increment corresponding to each drop in battery pack voltage when the detected voltage drop is greater than a preset voltage threshold and the number of drops exceeds a preset number, and select the minimum capacity increment from multiple capacity increments.

[0124] The battery pack voltage determination module 204 can be used to determine the target battery pack voltage corresponding to the minimum capacity increment.

[0125] The power offset determination module 205 can be used to obtain the current battery pack temperature and current battery pack current corresponding to the battery pack when multiple capacity increments, minimum capacity increments and target battery pack voltages all meet the second preset correction requirements, and determine the remaining power offset value based on the current battery pack temperature and current battery pack current.

[0126] The remaining power correction module 206 can be used to correct the current remaining power of the battery pack based on the remaining power offset value.

[0127] It is understood that the remaining power correction device 20 and the remaining power correction method in the above embodiments belong to the same inventive concept. The specific implementation of each module of the remaining power correction device 20 corresponds to each step of the remaining power correction method in the above embodiments, and will not be repeated here.

[0128] The module division described above is a logical functional division, and other division methods may be used in actual implementation. Furthermore, the functional modules in the various embodiments of this application can be integrated into the same processing unit, or each module can exist physically separately, or two or more modules can be integrated into the same unit. The integrated modules described above can be implemented in hardware or in a combination of hardware and software functional modules.

[0129] then Figure 3 In some embodiments, the energy storage device 30 is a device capable of automatically performing numerical calculations and / or information processing according to pre-set or stored instructions. Its hardware includes, but is not limited to, microprocessors, application-specific integrated circuits, programmable gate arrays, digital processors, and embedded devices.

[0130] Although not shown, the power supply connected to the energy storage device 30, including the memory 31 and controller 32, may include one or more DC or AC power supplies, recharging devices, power fault detection circuits, power converters or inverters, power status indicators, and other components. The energy storage device 30 may also include various sensors, Bluetooth modules, Wi-Fi modules, etc., which will not be described in detail here.

[0131] In some embodiments, the memory 31 stores a computer program that, when executed by at least one processor 35, implements all or part of the steps in a remaining battery power correction method. The memory 31 includes read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), one-time programmable read-only memory (OTPROM), electrically-erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, disk storage, magnetic tape storage, or any other computer-readable medium capable of carrying or storing data.

[0132] Furthermore, the computer-readable storage medium may primarily include a stored program area and a stored data area, wherein the stored program area may store the operating system, an application program required for at least one function, etc.; and the stored data area may store data created based on the use of the energy storage device 30, etc.

[0133] In some embodiments, at least one controller 32 is the control unit of the energy storage device 30. It connects to various components of the energy storage device 30 via various interfaces and lines, and executes programs or modules stored in the memory 31, as well as calling data stored in the memory 31, to perform various functions and process data within the energy storage device 30. For example, when at least one controller 32 executes a computer program stored in the memory, it implements all or part of the steps of the remaining power correction method in the embodiments of this application; or it implements all or part of the functions of the remaining power correction device. At least one controller 32 may be composed of integrated circuits, such as a single-packaged integrated circuit, or multiple integrated circuits with the same or different functions, including combinations of one or more central processing units (CPUs), microprocessors, digital processing chips, graphics processors, and various control chips.

[0134] The integrated unit implemented as a software functional module described above can be stored in a computer-readable storage medium. This software functional module, stored in a storage medium, includes several instructions to cause an energy storage device (which may be a personal computer, an energy storage device, or a network device, etc.) or a processor to execute portions of the methods of the various embodiments of this application.

[0135] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and other division methods may be used in actual implementation.

[0136] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0137] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or in the form of hardware plus software functional modules.

[0138] It will be apparent to those skilled in the art that this application is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this application. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be embraced within this application. No reference numerals in the claims should be construed as limiting the scope of the claims. Furthermore, it is clear that the word "comprising" does not exclude other elements or, and the singular does not exclude the plural. Multiple elements or devices recited in the specification may also be implemented by a single element or device through software or hardware. The terms "first," "second," etc., are used to indicate names and do not indicate any particular order.

[0139] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application.

Claims

1. A method for correcting residual power, applied to energy storage devices, characterized in that, The energy storage device includes a battery pack, and the remaining power correction method includes: The charging and discharging state of the battery pack, battery pack temperature, battery pack throughput change, and battery pack current are obtained. When the charging / discharging state, the battery pack temperature, the battery pack throughput change, and the battery pack current all meet the first preset correction requirements, the battery pack voltage is obtained. The first preset correction requirements include charging / discharging state requirements, battery pack temperature requirements, battery pack throughput change requirements, and battery pack current requirements. Timing begins when the charging / discharging state is a discharging state, the battery pack temperature is greater than a preset temperature threshold, the battery pack throughput change is greater than a preset throughput change threshold, and the battery pack current is within a preset current range with current fluctuations less than a preset fluctuation threshold. When the timing duration reaches a preset duration, it is determined that the charging / discharging state, battery pack temperature, battery pack throughput change, and battery pack current all meet the first preset correction requirements. When the voltage drop of the battery pack is detected to be greater than a preset voltage threshold and the number of drops exceeds a preset number, the capacity increment corresponding to each drop of the battery pack is obtained, and the smallest capacity increment is selected from multiple capacity increments. The number of drops represents the number of times the voltage drop of the battery pack is greater than the preset voltage threshold, and the capacity increment corresponding to each drop represents the capacity increment corresponding to each time the voltage drop of the battery pack is greater than the preset voltage threshold. Determine the target battery pack voltage corresponding to the minimum capacity increment; When the multiple capacity increments, the minimum capacity increment, and the target battery pack voltage all meet the second preset correction requirement, the current battery pack temperature and current battery pack current corresponding to the battery pack are obtained, and the remaining power offset value is determined based on the current battery pack temperature and current battery pack current. The second preset correction requirement includes a capacity increment requirement, a minimum capacity increment requirement, and a target battery pack voltage requirement. When the capacity increment change trend corresponding to the multiple capacity increments meets the preset capacity change trend, the minimum capacity increment is less than the target minimum capacity increment threshold, and the target battery pack voltage is within the target voltage range, it is determined that the multiple capacity increments, the minimum capacity increment, and the target battery pack voltage all meet the second preset correction requirement. The current remaining power of the battery pack is corrected based on the remaining power offset value.

2. The remaining power correction method as described in claim 1, characterized in that, Obtaining the battery pack throughput change of the battery pack includes: Obtain the current battery pack throughput and the battery pack throughput at the previous correction time. The change in battery pack throughput is determined based on the current battery pack throughput and the battery pack throughput at the previous correction time.

3. The remaining power correction method as described in claim 2, characterized in that, The step of determining the battery pack throughput change based on the current battery pack throughput and the battery pack throughput at the previous correction time includes: The difference between the current battery pack throughput and the battery pack throughput at the previous correction time is calculated to obtain the change in battery pack throughput.

4. The remaining power correction method as described in claim 1, characterized in that, The step of obtaining the capacity increment corresponding to each descent of the battery pack includes: When the voltage drop of the battery pack is equal to the preset voltage threshold, the corresponding capacity change value and voltage change value of the battery pack are determined; The capacity increment is determined based on the capacity change value and the voltage change value.

5. The remaining power correction method as described in claim 1, characterized in that, After selecting the smallest capacity increment from multiple capacity increments, the remaining power correction method further includes: Obtain the current battery pack temperature and current battery pack current corresponding to the battery pack; Based on the pre-set correspondence between battery pack temperature and battery pack current relative to high flat zone voltage, low flat zone voltage and minimum capacity increment threshold, the target high flat zone voltage, target low flat zone voltage and target minimum capacity increment threshold corresponding to the current battery pack temperature and the current battery pack current are determined. The target voltage range is determined based on the target high flat region voltage and the target low flat region voltage.

6. The remaining power correction method as described in claim 1, characterized in that, The step of determining the remaining power offset value based on the current battery pack temperature and the current battery pack current includes: Obtain the pre-set relationship between the battery pack temperature and the remaining charge corresponding to the boundary of the relatively flat area of ​​the battery pack current; Based on the current battery pack temperature and the current battery pack current, determine the first remaining charge at the boundary of the flat area corresponding to the battery pack; Obtain the second remaining power corresponding to the minimum capacity increment; The remaining power offset value is determined based on the first remaining power and the second remaining power.

7. The remaining power correction method as described in claim 1, characterized in that, The step of correcting the current remaining power of the battery pack based on the remaining power offset value includes: Obtain the change in remaining power corresponding to the battery pack. The change in remaining power represents the change in remaining power of the battery pack in a single operating cycle. The single operating cycle represents the complete process of the battery pack discharging from a first specified value of remaining power to a second specified value of remaining power, and then recharging back to the first specified value of remaining power. The dynamic catch-up rate is determined based on the current remaining power of the battery pack and the power offset value. The single-cycle power change value of the battery pack is determined based on the remaining power change and the dynamic catch-up ratio. The current remaining power of the battery pack is corrected based on the single power change value.

8. An energy storage device, characterized in that, The energy storage device includes a battery pack, a processor, and a memory, wherein the processor is used to implement the remaining power correction method as described in any one of claims 1 to 7 when executing a computer program stored in the memory.

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