Methods, devices, electronic equipment, and procedures for calibrating remaining battery capacity.

Abstract

This application discloses a method, apparatus, electronic device, and program product for calibrating the remaining battery capacity, relating to the field of battery technology. The method includes: upon detecting a reset command, collecting the remaining capacity of a target battery in a target vehicle at preset intervals; determining the cumulative error of the remaining capacity based on the remaining capacity of the target battery; determining whether the target battery is currently at a calibration time based on the cumulative error; adjusting the charging current of the target battery to a preset calibration current based on a current adjustment command; and calibrating the estimated remaining capacity value based on the voltage value of the target battery within a preset time window. This application solves the problem in related technologies where, during fast charging of lithium iron phosphate batteries, the large charging current causes the slope region between the first and second plateau regions of the open-circuit voltage-remaining capacity curve to disappear, rendering traditional slow charging calibration methods inapplicable and leading to inaccurate estimation of the remaining battery capacity.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a method, apparatus, electronic device, and program product for calibrating the remaining power of a battery. Background Technology

[0002] With the rapid development of the new energy vehicle industry, the accuracy of state estimation of power batteries, as core components, directly affects vehicle safety and user experience. Among these parameters, the remaining charge (State of Charge, SOC) is one of the most critical state parameters in the Battery Management System (BMS). Currently, the industry commonly uses a coulomb integral algorithm combined with the stability characteristics of the open circuit voltage (OCV)-SOC curve under specific operating conditions for periodic calibration to correct accumulated errors.

[0003] However, for widely used lithium iron phosphate batteries, their OCV-SOC curves exhibit significant nonlinear characteristics, primarily manifested as two relatively long voltage plateau regions, with only a very short voltage ramp region between the first and second plateau regions. In DC fast charging scenarios, due to the large charging current, significant ohmic and concentration polarization occur within the battery, leading to drastic fluctuations in the terminal voltage. This high-current polarization effect severely masks or even completely eliminates the already brief ramp region characteristics, causing the two plateau regions to merge on the dynamic voltage curve. This results in the voltage being extremely insensitive to changes in SOC, making it highly difficult to identify.

[0004] In the context of related technologies, during the fast charging process of lithium iron phosphate batteries, the large charging current causes the slope region between the first and second plateau regions in the open-circuit voltage-remaining capacity curve to disappear, rendering traditional slow charging calibration methods inapplicable and resulting in inaccurate estimation of the remaining battery capacity. Currently, no effective solution has been proposed. Summary of the Invention

[0005] The main objective of this application is to provide a method, apparatus, electronic device, and program product for calibrating the remaining battery capacity, in order to solve the problem in the related art where, during the fast charging process of lithium iron phosphate batteries, due to the large charging current, the slope area between the first and second plateau areas in the open circuit voltage-remaining capacity curve disappears, making traditional slow charging calibration methods unsuitable and resulting in inaccurate estimation of the remaining battery capacity.

[0006] To achieve the above objectives, according to one aspect of this application, a method for calibrating the remaining battery capacity is provided. This method is applied to a target vehicle and includes: upon detecting a reset command, acquiring the remaining battery capacity of a target battery in the target vehicle at preset intervals, wherein the reset command is used to reset the accumulated error of the remaining battery capacity; determining the accumulated error of the remaining battery capacity based on the remaining battery capacity; determining whether the target battery is currently in a period of remaining battery capacity calibration based on the accumulated error of the remaining battery capacity, the operating condition information of the target vehicle, the estimated remaining battery capacity of the target battery, and the battery temperature of the target battery; when the target battery is in a period of remaining battery capacity calibration, adjusting the charging current of the target battery to a preset calibration current based on a current adjustment command, wherein the preset calibration current is less than the target current corresponding to the charging condition; and calibrating the estimated remaining battery capacity based on the voltage value of the target battery within a preset time window to obtain the calibrated remaining battery capacity.

[0007] Furthermore, based on the remaining charge of the target battery, the cumulative error of the remaining charge is determined. Based on the cumulative error of the remaining charge, the operating condition information of the target vehicle, the estimated remaining charge of the target battery, and the battery temperature of the target battery, it is determined whether the target battery is currently in a period of remaining charge calibration. This includes: statistically analyzing the remaining charge of the target battery based on the coulomb integral error to obtain the cumulative error of the remaining charge; if the cumulative error of the remaining charge is detected to be greater than the preset cumulative error, collecting the operating condition information of the target vehicle; determining whether the target vehicle is in DC fast charging mode based on the operating condition information; and if the target vehicle is in DC fast charging mode, determining whether the current period of remaining charge calibration is in a period of remaining charge calibration based on the remaining charge of the target battery and the battery temperature of the target battery.

[0008] Furthermore, determining whether the current time is for remaining capacity calibration based on the remaining capacity and temperature of the target battery includes: determining the first remaining capacity of the target battery based on the battery management system of the target battery, and collecting the lowest cell temperature of the target battery; determining whether the first remaining capacity is within a first numerical range, wherein the lower limit of the first numerical range is less than the initial remaining capacity corresponding to the standard ramp zone of the lithium iron phosphate battery, and the upper limit of the first numerical range is less than the sum of the initial remaining capacity and the preset maximum cumulative error; determining whether the lowest cell temperature is greater than a preset temperature, wherein the preset temperature is obtained experimentally based on the polarization characteristics and voltage stability of the battery at different temperatures; and determining that the current time is for remaining capacity calibration if the first remaining capacity value is within the first numerical range and the lowest cell temperature is greater than the preset temperature.

[0009] Furthermore, determining whether the target vehicle is in DC fast charging mode based on operating condition information includes: acquiring the target vehicle's bus signal and determining whether the target vehicle is in a parked state based on the bus signal; if the target vehicle is in a parked state, acquiring the connection status signal between the target vehicle and the external charging equipment and determining whether the target vehicle is in a charging connection state based on the connection status signal; if the target vehicle is in a charging connection state, acquiring the target vehicle's charging current signal and identifying the current type and current amplitude based on the charging current signal; if the current type is a DC signal and the current amplitude is greater than a preset amplitude, determining that the target vehicle is in DC fast charging mode.

[0010] Further, the remaining capacity estimate is calibrated based on the target battery voltage value within a preset time window to obtain the calibrated remaining capacity of the target battery. This includes: after executing the current adjustment command, acquiring the charging current signal of the target battery, and determining the charging current and charging current fluctuation amplitude based on the charging current signal; when the charging current is less than the preset calibration current and the charging current fluctuation amplitude is less than the preset amplitude, acquiring the single-cell terminal voltage of the target battery based on a preset sampling period; when the single-cell terminal voltage is detected to be within the preset ramp voltage range and the voltage fluctuation amplitude of the single-cell terminal voltage is less than the preset amplitude, determining the current voltage of the target battery as the ramp characteristic voltage; and querying the calibration condition database based on the ramp characteristic voltage to obtain the calibrated remaining capacity. The calibration condition database stores the mapping relationship between the voltage calibrated by the charge and discharge experiment for the preset calibration current and the remaining capacity.

[0011] Furthermore, adjusting the charging current of the target battery to a preset calibration current based on the current adjustment command includes: determining the first current corresponding to the target battery when it is in DC charging mode based on historical charging data; generating a first arithmetic sequence based on the first current and the preset calibration current; generating a first current adjustment command based on each value in the first arithmetic sequence; and sending the first current adjustment command to the DC charger of the external charging device through the battery management system of the target battery at preset intervals.

[0012] Furthermore, after calibrating the estimated remaining capacity based on the voltage value of the target battery within a preset time window to obtain the calibrated remaining capacity of the target battery, the above method further includes: generating a second arithmetic sequence based on a preset calibration current and a charging current; generating a second current adjustment command based on each value in the second arithmetic sequence; sending the second current adjustment command to the DC charger of the external charging device through the battery management system of the target battery at preset intervals; and resetting the accumulated error of the remaining capacity of the target battery.

[0013] To achieve the above objectives, according to another aspect of this application, a battery remaining power calibration device is provided. This device is deployed in a target vehicle and includes: a data acquisition unit, configured to acquire the remaining power of a target battery in the target vehicle at preset intervals upon detecting a reset command, wherein the reset command is used to reset the accumulated error of the remaining power of the target battery; a judgment unit, configured to determine the accumulated error of the remaining power based on the remaining power of the target battery, and to determine whether the target battery is currently in a remaining power calibration period based on the accumulated error of the remaining power, the operating condition information of the target vehicle, the estimated remaining power of the target battery, and the battery temperature of the target battery; an adjustment unit, configured to adjust the charging current of the target battery to a preset calibration current based on a current adjustment command when the target battery is in a remaining power calibration period, wherein the preset calibration current is less than the target current corresponding to the charging condition; and a calibration unit, configured to calibrate the estimated remaining power based on the voltage value of the target battery within a preset time window to obtain the calibrated remaining power of the target battery.

[0014] Furthermore, the judgment unit includes: a statistics subunit, used to statistically analyze the remaining charge of the target battery based on the coulomb integral error to obtain the cumulative error of the remaining charge; a first acquisition subunit, used to acquire the operating condition information of the target vehicle when the cumulative error of the remaining charge is detected to be greater than a preset cumulative error; a first judgment subunit, used to determine whether the target vehicle is in DC fast charging mode based on the operating condition information; and a second judgment subunit, used to determine whether the current time is for remaining charge calibration based on the remaining charge of the target battery and the battery temperature when the target vehicle is in DC fast charging mode.

[0015] Furthermore, the second judgment subunit includes: a data acquisition module, used to determine the first remaining charge of the target battery based on the battery management system of the target battery, and to acquire the lowest cell temperature of the target battery; a first judgment module, used to determine whether the first remaining charge belongs to a first numerical range, wherein the lower limit of the first numerical range is less than the initial remaining charge corresponding to the standard ramp zone of the lithium iron phosphate battery, and the upper limit of the first numerical range is less than the sum of the initial remaining charge and the preset maximum cumulative error; a second judgment module, used to determine whether the lowest cell temperature is greater than a preset temperature, wherein the preset temperature is obtained experimentally based on the polarization characteristics and voltage stability of the battery at different temperatures; and a first determination module, used to determine that the current time is for remaining charge calibration when the first remaining charge value belongs to the first numerical range and the lowest cell temperature is greater than the preset temperature.

[0016] Furthermore, the first judgment subunit includes: a third judgment module, used to collect the bus signal of the target vehicle and determine whether the target vehicle is in a parked state based on the bus signal; a fourth judgment module, used to collect the connection status signal between the target vehicle and the external charging device when the target vehicle is in a parked state, and determine whether the target vehicle is in a charging connection state based on the connection status signal; an identification module, used to collect the charging current signal of the target vehicle when the target vehicle is in a charging connection state, and identify the current type and current amplitude based on the charging current signal; and a second determination module, used to determine that the target vehicle is in DC fast charging mode when the current type is a DC signal and the current amplitude is greater than a preset amplitude.

[0017] Further, the calibration unit includes: a first determining subunit, used to acquire the charging current signal of the target battery after executing the current adjustment command, and determine the charging current and the charging current fluctuation amplitude based on the charging current signal; a second acquiring subunit, used to acquire the single-cell terminal voltage of the target battery based on a preset sampling period when the charging current is less than the preset calibration current and the charging current fluctuation amplitude is less than the preset amplitude; a second determining subunit, used to determine the current voltage of the target battery as the slope characteristic voltage when it is detected that the single-cell terminal voltage is within the preset slope voltage range and the voltage fluctuation amplitude of the single-cell terminal voltage is less than the preset amplitude; and a query subunit, used to query the calibration condition database based on the slope characteristic voltage to obtain the remaining capacity after calibration, wherein the calibration condition database stores the mapping relationship between the voltage calibrated by the charge and discharge experiment for the preset calibration current and the remaining capacity.

[0018] Furthermore, the adjustment unit includes: a third determining subunit, used to determine the first current corresponding to the target battery when it is in DC charging condition based on historical charging data; a first generating subunit, used to generate a first arithmetic sequence based on the first current and a preset calibration current; a second generating subunit, used to generate a first current adjustment command based on each value in the first arithmetic sequence; and a sending subunit, used to send the first current adjustment command to the DC charger of the external charging device through the battery management system of the target battery at preset intervals.

[0019] Furthermore, the aforementioned apparatus further includes: a first generation unit, configured to calibrate the estimated remaining capacity based on the voltage value of the target battery within a preset time window, and after obtaining the calibrated remaining capacity of the target battery, generate a second arithmetic sequence based on a preset calibration current and a charging current; a second generation unit, configured to generate a second current adjustment command based on each value in the second arithmetic sequence; a sending unit, configured to send the second current adjustment command to the DC charger of an external charging device through the battery management system of the target battery at preset intervals; and a processing unit, configured to reset the accumulated error of the remaining capacity of the target battery.

[0020] To achieve the above objectives, according to one aspect of this application, a computer program product is provided, including a computer program that, when executed by a processor, implements any of the above-described methods for calibrating the remaining battery power, and when executed by a processor, implements the steps of the battery remaining power calibration methods in various embodiments of this application.

[0021] To achieve the above objectives, according to one aspect of this application, a computer-readable storage medium is provided, the computer-readable storage medium including stored computer instructions, wherein, when the computer instructions are executed by a processor, the calibration method for any of the above-mentioned battery remaining power is implemented.

[0022] To achieve the above objectives, according to one aspect of this application, an electronic device is provided, including one or more processors and a memory, the memory being used to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors cause the one or more processors to implement any of the above-described battery remaining power calibration methods.

[0023] In this embodiment, upon detecting a reset command, the remaining charge of the target battery in the target vehicle is collected at preset intervals. The reset command is used to reset the accumulated error of the target battery's remaining charge. The accumulated error is determined based on the remaining charge of the target battery. The system then determines whether the target battery is currently in a remaining charge calibration period based on the accumulated error, the target vehicle's operating condition information, the estimated remaining charge of the target battery, and the battery temperature. If the target battery is in a remaining charge calibration period, the charging current of the target battery is adjusted to a preset calibration current based on a current adjustment command. This preset calibration current is less than the target current corresponding to the charging condition. The estimated remaining charge is calibrated based on the voltage value of the target battery within a preset time window to obtain the calibrated remaining charge of the target battery. This system can periodically collect the remaining charge and calculate the accumulated error in real time. When an error is detected... When the current exceeds the threshold and is in DC fast charging mode, the current is actively reduced to the preset calibration current by issuing a current adjustment command. This eliminates the severe polarization effect caused by the large current and restores the slope region characteristics in the open-circuit voltage-remaining capacity curve. Even during fast charging without static conditions, the slope region voltage can be used to accurately calibrate the estimated remaining capacity value. This avoids the limitation of traditional methods in correcting accumulated errors under dynamic fast charging conditions, thus improving the technical effect of estimating the remaining capacity of lithium iron phosphate batteries in fast charging scenarios. Therefore, it can solve the technical problem in related technologies where, during fast charging of lithium iron phosphate batteries, the slope region between the first and second plateau regions of the open-circuit voltage-remaining capacity curve disappears due to the large charging current, making traditional slow charging calibration methods unsuitable and resulting in inaccurate estimation of the remaining battery capacity. This achieves the technical effect of improving the accuracy and reliability of remaining capacity estimation for lithium iron phosphate batteries. Attached Figure Description

[0024] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0025] Figure 1 This is a hardware structure block diagram of a computer terminal (or mobile device) for implementing a method for calibrating the remaining battery power, according to Embodiment 1 of this application.

[0026] Figure 2 This is a flowchart of an optional battery remaining power calibration method provided according to Embodiment 1 of this application;

[0027] Figure 3 This is a schematic diagram of the open-circuit voltage-remaining capacity curve of an optional lithium iron phosphate battery according to Embodiment 1 of this application;

[0028] Figure 4This is a flowchart illustrating an optional battery SOC estimation method provided in Embodiment 1 of this application;

[0029] Figure 5 This is a schematic diagram of a battery remaining power calibration device according to Embodiment 2 of this application;

[0030] Figure 6 This is a schematic diagram of a calibration electronic device for remaining battery power provided according to Embodiment 3 of this application. Detailed Implementation

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0032] It should be noted that the information collected in this application (including but not limited to user device information, user personal information, collected data, used data, generated data, processed data, etc.) and the data (including but not limited to data used for analysis, stored data, displayed data, collected information, used information, generated information, processed information, etc.) are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, storage, use, processing, transmission, provision, disclosure, and application of the relevant data all comply with the relevant laws and standards of the relevant regions, do not violate public order and good morals, and provide corresponding operation entry points for users to choose to authorize or refuse. For example, this system has interfaces with relevant users or organizations, providing users with corresponding operation entry points for users to choose to agree to or refuse automated decision results; if the user chooses to refuse, the process proceeds to the expert decision-making process.

[0033] Example 1

[0034] According to an embodiment of this application, a method embodiment for calibrating the remaining battery power is also provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0035] The method embodiment provided in Embodiment 1 of this application can be executed in a mobile terminal, computer terminal or similar computing device. Figure 1 This is a hardware structure block diagram of a computer terminal (or mobile device) for implementing a method for calibrating remaining battery power, according to Embodiment 1 of this application. Figure 1As shown, the computer terminal 10 (or mobile device) may include one or more processors 102 (shown as 102a, 102b, ..., 102n in the figure) 102 (processor 102 may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.), a memory 104 for storing data, and a transmission device 106 for communication functions. In addition, it may also include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of a BUS bus), a network interface, a power supply, and / or a camera. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the aforementioned electronic device. For example, computer terminal 10 may also include... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0036] It should be noted that the aforementioned one or more processors 102 and / or other data processing circuits are generally referred to herein as "data processing circuits". These data processing circuits may be embodied, in whole or in part, in software, hardware, firmware, or any other combination thereof. Furthermore, the data processing circuits may be a single, independent processing module, or may be integrated, in whole or in part, into any other element within the computer terminal 10 (or mobile device). As involved in the embodiments of this application, the data processing circuits serve as a processor control mechanism (e.g., selection of a variable resistor termination path connected to an interface).

[0037] The memory 104 can be used to store software programs and modules of application software, such as the program instructions / data storage device corresponding to the battery remaining power calibration method in this embodiment. The processor 102 executes various functional applications and data processing by running the software programs and modules stored in the memory 104, thereby realizing the aforementioned battery remaining power calibration method. The memory 104 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the computer terminal 10 via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0038] The transmission device 106 is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by the communication provider of the computer terminal 10. In one example, the transmission device 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 106 may be a Radio Frequency (RF) module, used for wireless communication with the Internet.

[0039] The display may be, for example, a touchscreen liquid crystal display (LCD) that allows the user to interact with the user interface of the computer terminal 10 (or mobile device).

[0040] Under the aforementioned operating environment, this application provides the following: Figure 2 The method for calibrating the remaining battery power shown above is applied to the target vehicle. Figure 2 This is a flowchart of an optional battery remaining power calibration method provided according to Embodiment 1 of this application.

[0041] Step S201: When a reset command is detected, the remaining charge of the target battery in the target vehicle is collected at preset intervals. The reset command is used to reset the accumulated error of the remaining charge of the target battery.

[0042] The executing entity in this embodiment 1 can be a battery management system (BMS). This system, during DC fast charging, triggers a state of charge (SOC, or remaining charge) cumulative error threshold. By identifying the DC fast charging condition, determining the SOC range, and considering battery temperature, it adjusts the charging current from the rated fast charging current to a small slow charging calibration current to restore the battery's ramp voltage characteristics. After capturing the characteristic voltage of the ramp region, it looks up a table to correct the SOC value. Finally, it restores the fast charging current and resets the error. This closed-loop calibration logic solves the problem of ramp characteristics disappearing due to high current polarization under dynamic DC fast charging conditions, avoids frequent calibration, improves SOC estimation accuracy, and simultaneously maintains charging efficiency.

[0043] Optionally, in this embodiment 1, Figure 3 This is a schematic diagram of the open-circuit voltage-remaining capacity curve of an optional lithium iron phosphate battery according to Embodiment 1 of this application. Figure 3As shown, the relationship between static voltage and charge exhibits a sloping region between the first and second plateau regions. In daily use, the charge level can be corrected based on the static voltage falling within this range. However, this region is difficult to utilize for correction during dynamic charging and discharging. During slow charging, the small charging current and minimal polarization allow for correction under these conditions. However, during fast charging, the large charging current causes the sloped region to disappear, merging the first and second plateau regions into a single plateau, making correction impossible. Therefore, this solution proactively limits the charging current during fast charging to create a sloping region, thereby enabling charge level correction and improving SOC estimation accuracy.

[0044] In this embodiment 1, in order to eliminate the accumulated error and start a new monitoring cycle after the SOC calibration is completed, the remaining power of the target battery can be periodically collected in response to the reset command to reset the accumulated error, thereby clearing the historical error data and re-performing the SOC estimation monitoring.

[0045] The reset command is a signal or control logic used to reset the accumulated error of the target battery's remaining capacity. The accumulated error of the remaining capacity refers to the cumulative deviation of the SOC estimate, calculated by the BMS through continuous real-time acquisition of battery charging and discharging current and operating time since the last SOC calibration was completed and the error was cleared. The preset period refers to the time interval used by the system to periodically collect the remaining capacity during a new round of monitoring. For example, the preset period can be any reasonable time interval such as 1 second, 10 seconds, or 1 minute, and the specific value can be determined based on the sampling frequency and computing resources of the BMS system.

[0046] By resetting the accumulated error of the remaining power of the target battery using a reset command and periodically collecting the remaining power to monitor new accumulated errors, this technology solves the problem of calibration cycle interruption or manual intervention required in traditional technologies. It achieves the technical effect of accurate SOC calibration throughout the entire life cycle and continuously ensures the stable accuracy of battery SOC estimation.

[0047] Step S202: Determine the remaining power accumulation error based on the remaining power of the target battery, and determine whether the target battery is currently in the remaining power calibration period based on the remaining power accumulation error, the operating condition information of the target vehicle, the estimated remaining power of the target battery, and the battery temperature of the target battery.

[0048] In this embodiment 1, to achieve accurate SOC calibration under dynamic operating conditions, the absolute value of the deviation between the current estimated SOC value and the actual value can be calculated in real time by continuously collecting charging and discharging current and operating time, i.e., the cumulative error of remaining power. The BMS parses the vehicle's CAN bus signal to identify whether the vehicle is currently in DC fast charging, AC slow charging, driving, or stationary state. Then, after the error threshold is triggered and it is in DC fast charging condition, the BMS further verifies whether the current estimated SOC value is within the preset advanced calibration range (e.g., 50%~55%) and whether the minimum battery temperature is higher than the critical threshold (e.g., T). Only when all conditions are met simultaneously is it determined that it is time to perform calibration.

[0049] Step S203: When the target battery is in the remaining power calibration period, the charging current of the target battery is adjusted to the preset calibration current based on the current adjustment command, wherein the preset calibration current is less than the target current corresponding to the charging condition.

[0050] In this embodiment 1, in order to restore the battery voltage characteristics for calibration, a specific current adjustment command can be sent to the external DC charging equipment through the vehicle communication network (such as CAN bus), requesting the charging equipment to reduce the current output current. The preset calibration current is a pre-set small value (e.g., 10A), which is significantly smaller than the large current under the current DC fast charging condition (e.g., 100A or higher); the target current corresponding to the charging condition refers to the large rated current required to maintain fast charging efficiency.

[0051] By adjusting the charging current of the target battery to a preset calibration current based on the current regulation command, the polarization effect can be reduced and the characteristics of the slope region of the battery OCV-SOC curve can be restored, thereby achieving the technical effect of creating favorable working conditions for subsequent SOC calibration.

[0052] Step S204: The remaining power estimate is calibrated based on the voltage value of the target battery within a preset time window to obtain the calibrated remaining power of the target battery.

[0053] In this embodiment 1, in order to eliminate accumulated errors by utilizing the slope region voltage characteristics, the single-cell terminal voltage of the target battery can be continuously monitored after the charging current is reduced to the preset calibration current and stabilized. When it is determined that an effective slope region characteristic voltage has been captured, the captured stable characteristic voltage is used as an index to search in the pre-stored experimental calibration database to obtain the true standard SOC value (i.e., the true standard SOC value) corresponding to the voltage value. The true standard SOC value is then used to directly overwrite the remaining capacity estimate obtained by the Coulomb integral algorithm, thereby completing the calibration.

[0054] By reducing the charging current to a preset calibration current and stabilizing it, the remaining charge of the calibrated target battery can be found based on the captured stable characteristic voltage. The SOC can be accurately corrected using the slope voltage after the battery stabilizes, thus achieving the technical effect of eliminating long-term accumulated errors and improving the accuracy of the remaining battery charge.

[0055] Optionally, in the battery remaining power calibration method provided in Embodiment 1 of this application, the remaining power cumulative error is determined based on the remaining power of the target battery, and the target battery is judged to be in a remaining power calibration time based on the remaining power cumulative error, the operating condition information of the target vehicle, the estimated remaining power of the target battery, and the battery temperature of the target battery. This includes: statistically analyzing the remaining power of the target battery based on the coulomb integral error to obtain the remaining power cumulative error; when the remaining power cumulative error is detected to be greater than a preset cumulative error, collecting the operating condition information of the target vehicle; judging whether the target vehicle is in DC fast charging mode based on the operating condition information; and when the target vehicle is in DC fast charging mode, judging whether the current time is a remaining power calibration time based on the remaining power of the target battery and the battery temperature of the target battery.

[0056] In this embodiment 1, in order to achieve precise triggering of the SOC calibration process on demand, the accumulated error can be statistically analyzed in real time and the operating conditions and conditions can be determined only when the error exceeds the standard and DC fast charging is in progress. This can avoid frequent calibration and lock the calibration time in the fast charging scenario.

[0057] Specifically, since the last SOC calibration was completed and reset, the battery management system continuously collects battery charging and discharging current and operating time in real time. It then uses a coulomb integral algorithm to iteratively calculate the cumulative change in battery capacity frame by frame, and records the absolute value of the deviation between the estimated and actual coulomb integral values ​​within this calibration cycle, defined as the remaining capacity cumulative error. The formula for calculating the remaining capacity cumulative error can be expressed as: .

[0058] Then, the BMS determines in real time whether the accumulated error of the currently calculated remaining battery power meets the preset trigger threshold (e.g., 5%). When the error is detected to be greater than this threshold, it is determined that there is a significant estimation inaccuracy. Subsequently, the operating conditions of the target vehicle are collected, and the signals sent by the Vehicle Control Unit (VCU) or charger through the Controller Area Network (CAN) bus are analyzed. The BMS analyzes the collected operating condition information, and combines it with multi-dimensional signals such as the vehicle's parking status, the signal from the external DC fast charging device, and the fact that the charging current is a high DC current mode, to exclude non-target scenarios such as driving, idling, and AC slow charging, thereby confirming whether the vehicle is currently in DC fast charging mode. DC fast charging mode refers to the operating state in which the vehicle is connected to a DC charger and is charging with a large DC current, such as a DC charging scenario with a charging current greater than 50A. After confirming that it is in DC fast charging mode, the BMS further determines whether the estimated remaining power is within the preset advanced calibration range (e.g., 50%-55%), and then determines whether the lowest temperature of all cells in the battery pack is higher than the preset critical temperature threshold. Only when the remaining power and battery temperature meet the conditions at the same time is it determined that it is currently in the time for remaining power calibration.

[0059] By monitoring the accumulated error in real time, the calibration is triggered only when the error exceeds the standard. Furthermore, by screening DC fast charging conditions and specific SOC ranges and temperature conditions, the calibration timing can be accurately located. This avoids invalid calibration in non-fast charging scenarios or when the error is low. Resources are concentrated on solving the polarization problem caused by the high current of fast charging, thereby improving the targeting and effectiveness of SOC calibration triggering.

[0060] Optionally, in the battery remaining capacity calibration method provided in Embodiment 1 of this application, determining whether the current time is for remaining capacity calibration based on the remaining capacity and battery temperature of the target battery includes: determining the first remaining capacity of the target battery based on the battery management system of the target battery, and collecting the lowest cell temperature of the target battery; determining whether the first remaining capacity belongs to a first numerical range, wherein the lower limit of the first numerical range is less than the initial remaining capacity corresponding to the standard ramp zone of the lithium iron phosphate battery, and the upper limit of the first numerical range is less than the sum of the initial remaining capacity and the preset maximum cumulative error; determining whether the lowest cell temperature is greater than a preset temperature, wherein the preset temperature is obtained experimentally based on the polarization characteristics and voltage stability of the battery at different temperatures; and determining that the current time is for remaining capacity calibration if the first remaining capacity value belongs to the first numerical range and the lowest cell temperature is greater than the preset temperature.

[0061] In this embodiment 1, in order to accurately lock the optimal SOC range and temperature conditions for current reduction calibration under DC fast charging conditions, the SOC range can be determined by obtaining the remaining battery capacity and the lowest temperature, combined with the starting point of the ramp zone and the error range, and the polarization state can be determined based on the temperature threshold calibrated in the experiment. This can avoid missing the calibration window or miscalibrating at low temperatures, and ensure that the current reduction can be successfully entered into the ramp zone to complete high-precision calibration.

[0062] Specifically, the BMS estimates the current remaining battery capacity (SOC) using an internal algorithm and reads the temperature of all cells from the temperature sensor network within the battery pack, selecting the minimum value as the cell's lowest temperature. Based on the laboratory-calibrated open-circuit voltage-remaining capacity curve of the lithium iron phosphate battery, the BMS determines the initial remaining capacity of the standard ramp zone (e.g., 51%). Combining this with the system's maximum allowable cumulative error (e.g., 5%), it sets a pre-calibrated remaining capacity range, i.e., the first numerical range, specifically 50% to 55%. The lower limit of the first numerical range is below the ramp zone's starting point, and the upper limit is below the sum of the starting point and the maximum error, aiming to enter this range early to allow time for depolarization. The BMS compares the collected lowest cell temperature with a preset temperature threshold. This preset temperature threshold (specifically 0℃, 5℃, 10℃, etc.) is a critical value determined through laboratory multi-temperature charge-discharge experiments, analyzing the battery polarization impedance and voltage fluctuations at different temperatures. Below this temperature, severe battery polarization leads to voltage instability; above this temperature, battery polarization is controllable. Finally, only when the first remaining charge is within the first value range and the lowest cell temperature is higher than the preset temperature threshold, will the BMS determine that it is time to calibrate the remaining charge, thereby triggering the subsequent current reduction operation.

[0063] By pre-setting a SOC lead range based on the starting point of the ramp zone and combining it with experimentally calibrated temperature thresholds for dual condition determination, the optimal time for calibration can be identified before the ramp zone disappears due to the high current of fast charging. This avoids missing the window due to error drift or calibration failure due to low-temperature polarization, thereby improving the trigger success rate and calibration accuracy of SOC calibration during fast charging and ensuring that the ramp zone voltage can be accurately captured and corrected after current reduction.

[0064] Optionally, in the battery remaining power calibration method provided in Embodiment 1 of this application, determining whether the target vehicle is in DC fast charging mode based on operating condition information includes: collecting the bus signal of the target vehicle and determining whether the target vehicle is in a parked state based on the bus signal; when the target vehicle is in a parked state, collecting the connection status signal between the target vehicle and the external charging device and determining whether the target vehicle is in a charging connection state based on the connection status signal; when the target vehicle is in a charging connection state, collecting the charging current signal of the target vehicle and identifying the current type and current amplitude based on the charging current signal; and determining that the target vehicle is in DC fast charging mode when the current type is a DC signal and the current amplitude is greater than a preset amplitude.

[0065] In this embodiment 1, in order to accurately identify whether the current vehicle is in a specific DC fast charging condition that requires SOC calibration, the parking and charging connection status can be determined by analyzing the bus signal, and the DC type and large current amplitude of the charging current can be further identified. This can eliminate non-target scenarios such as driving, stationary, and slow charging, and ensure that the subsequent calibration logic is triggered only under DC fast charging.

[0066] Specifically, the BMS receives vehicle status signals from the Vehicle Control Unit (VCU) or gateway via the Controller Area Network (CAN) bus, and parses information indicating vehicle gear position, speed, or ignition status. When it detects a vehicle speed of 0 and the gear in P (Park) or power off, it determines that the vehicle is in a parked state. Specific values ​​for the parked state include, for example, P (Park) or N (Neutral) with a vehicle speed of 0. The BMS collects physical connection detection signals or charger handshake status signals at the charging interface to confirm that the charging gun is inserted into the vehicle's charging port and that a communication connection has been established, thus determining that the vehicle is in a charging connection state and ruling out cases where the charging equipment is not connected. The BMS reads the real-time charging current value and current type identifier sent by the charger via the bus, or directly collects the current signal flowing to the battery through a Hall sensor, analyzes whether the current is direct current (DC) or alternating current (AC), and obtains its instantaneous current value. For example, the current value is 100A, and the current type is DC. If the BMS determines that the type of the current signal collected is DC and its amplitude exceeds the preset fast charging current threshold (e.g., 50A or 60A), it will determine that the vehicle is currently undergoing high-current DC fast charging, i.e., it is in DC fast charging mode, thereby triggering the subsequent calibration process.

[0067] By analyzing vehicle status, connection status, and charging current attributes at multiple levels, the system accurately identifies DC high-current charging scenarios. This effectively eliminates interference from AC slow charging, driving conditions, and stationary conditions, ensuring that the SOC calibration logic is only activated in DC fast charging scenarios where the characteristics of the ramp area disappear. This improves the accuracy and specificity of operating condition identification, avoids erroneous current reduction calibration in non-fast charging scenarios, and ensures charging efficiency and reasonable utilization of system resources.

[0068] Optionally, in the battery remaining capacity calibration method provided in Embodiment 1 of this application, the remaining capacity estimate is calibrated based on the voltage value of the target battery within a preset time window to obtain the calibrated remaining capacity of the target battery. This includes: after executing the current adjustment command, acquiring the charging current signal of the target battery, and determining the charging current and the charging current fluctuation amplitude based on the charging current signal; when the charging current is less than the preset calibration current and the charging current fluctuation amplitude is less than the preset amplitude, acquiring the single-cell terminal voltage of the target battery based on a preset sampling period; when it is detected that the single-cell terminal voltage is within a preset ramp voltage range and the voltage fluctuation amplitude of the single-cell terminal voltage is less than the preset amplitude, determining the current voltage of the target battery as the ramp characteristic voltage; querying the calibration condition database based on the ramp characteristic voltage to obtain the calibrated remaining capacity, wherein the calibration condition database stores the mapping relationship between the voltage calibrated by the charge and discharge experiment for the preset calibration current and the remaining capacity.

[0069] In this embodiment 1, in order to accurately capture the characteristic voltage of the battery ramp region and achieve high-precision SOC calibration after current reduction, the individual cell voltage can be collected after the current stabilizes, the characteristic voltage of the ramp region can be identified, and the SOC can be queried and corrected using calibration data under the same operating conditions. This can eliminate the cumulative error of coulomb integration and improve the SOC estimation accuracy during fast charging.

[0070] Specifically, after issuing a current reduction command, the BMS collects the charging current signal of the battery pack in real time through a current sensor, calculates the instantaneous value of the current charging current and the voltage / current change rate within a preset time window to assess whether the current has smoothly transitioned to the target calibration current. The BMS determines whether the current charging current has dropped below the preset calibration low current (e.g., 10A) and whether the current fluctuation amplitude is below the allowable stability threshold. After confirming that the current has entered a steady state, it starts a high-frequency sampling program, reading the terminal voltage data of each individual cell in the battery pack according to a preset sampling period (e.g., 100ms). The BMS monitors the collected individual cell terminal voltages in real time. When the voltage value falls within a preset ramp voltage range (e.g., 3.30V-3.33V), and the voltage fluctuation amplitude within multiple consecutive sampling periods is below the preset stability threshold, the battery is determined to be in a weakly polarized steady state. This stable voltage value is confirmed as the currently valid ramp characteristic voltage, for example, 3.31V, 3.32V, etc. The BMS uses the determined ramp characteristic voltage as an index to perform a matching query in a pre-stored calibration condition database. This database is based on charge-discharge experimental data conducted in the laboratory under the same preset calibration current. It records the stable voltage values ​​corresponding to different remaining charge (SOC). The actual remaining charge corresponding to the current voltage, i.e., the calibrated remaining charge, is obtained through table lookup or interpolation algorithms. For example, a voltage of 3.31V corresponds to a remaining charge of 62%.

[0071] By accurately capturing the characteristic voltage of the ramp region after the current stabilizes and using calibration data under the same operating conditions for mapping correction, the polarization interference caused by the large current of fast charging can be overcome. The high sensitivity of the ramp region voltage to the SOC can be used to achieve accurate calibration, thereby eliminating the long-term accumulated SOC estimation error and improving the state estimation accuracy of the battery management system under dynamic fast charging conditions.

[0072] Optionally, in the battery remaining power calibration method provided in Embodiment 1 of this application, adjusting the charging current of the target battery to a preset calibration current based on a current adjustment command includes: determining a first current corresponding to the target battery when it is in DC charging mode based on historical charging data; generating a first arithmetic sequence based on the first current and the preset calibration current; generating a first current adjustment command based on each value in the first arithmetic sequence; and sending the first current adjustment command to the DC charger of the external charging device through the battery management system of the target battery at preset intervals.

[0073] In this embodiment 1, in order to achieve a smooth transition of charging current to avoid voltage surges and ensure the stable establishment of calibration conditions, an arithmetic sequence can be generated based on the current fast charging current and the preset calibration current, and a step-by-step current reduction command can be sent to the charger in a time-sharing manner. This can eliminate voltage fluctuations caused by sudden current changes and create conditions for battery polarization reduction and voltage stabilization.

[0074] Specifically, the BMS monitors or reads the actual output current value of the charger during the ongoing DC charging process in real time, or determines the initial or current high current value as the first current corresponding to the target battery under DC charging conditions based on the target maximum current set by the charger in the most recent charging session. The BMS calculates the difference between the first current and the preset calibration low current (e.g., 10A), sets a reasonable step size (e.g., 5A or 10A), and starts from the first current, decreasing it in fixed steps until it reaches or slightly falls below the preset calibration current, thereby generating a series of intermediate current values, forming a first arithmetic sequence, for example, [120A, 110A, 100A, ..., 10A]. For each target current value in the first arithmetic sequence, the BMS generates a corresponding current adjustment command. This command includes the target current value, command type (e.g., current reduction command), and communication identifier, used to instruct the external charging device to adjust the output current to that specific value, for example, a CAN message ID 0x123 containing the target current value of 110A. The BMS sends current regulation commands corresponding to the first arithmetic sequence to the external DC charger at preset time intervals (such as 1 second or 2 seconds). For example, it first sends a command to reduce the current to 110A, waits for an interval, and then sends a command to reduce the current to 100A, until the preset calibration current is finally reached, thus achieving a step-by-step smooth current reduction.

[0075] By using arithmetic progressions to plan a stepped current reduction path and sending commands in a time-division manner, it is possible to avoid drastic fluctuations and shocks in battery terminal voltage caused by a sudden and significant drop in charging current. This ensures a smooth transition of the battery's internal polarization state, achieving the technical effect of ensuring stable restoration of voltage characteristics and providing a reliable steady-state environment for subsequent accurate capture of characteristic voltages in the slope region.

[0076] Optionally, in the battery remaining power calibration method provided in Embodiment 1 of this application, after calibrating the estimated remaining power value based on the voltage value of the target battery within a preset time window to obtain the calibrated remaining power of the target battery, the method further includes: generating a second arithmetic sequence based on a preset calibration current and a charging current; generating a second current adjustment command based on each value in the second arithmetic sequence; sending the second current adjustment command to the DC charger of the external charging device through the battery management system of the target battery at preset intervals; and resetting the accumulated error of the remaining power of the target battery.

[0077] In this embodiment 1, in order to restore the original fast charging efficiency and clear the accumulated error to start a new round of monitoring after completing the SOC calibration, a recovery command can be sent by generating an arithmetic sequence of current boost based on the calibration current and the original fast charging current, and the SOC accumulated error can be reset. This ensures the continuity of the charging process, eliminates the estimation deviation in this calibration cycle, and achieves periodic accurate calibration.

[0078] Specifically, after calibration, the BMS uses the current preset calibration current (e.g., 10A) as the starting point and the previously limited DC fast charging rated current (e.g., 120A) as the target endpoint. It calculates the difference between the two, sets a fixed step size (e.g., 5A or 10A), and increments it from the preset calibration current until it reaches or exceeds the original fast charging current, thus generating a series of intermediate current values, forming a second arithmetic progression, for example, [10A, 15A, 20A, ..., 120A]. For each target current value in the second arithmetic progression, the BMS generates a corresponding current adjustment command. This command includes the target current value, command type (e.g., current boost command), and communication identifier, instructing the external charging device to adjust the output current to that specific value to gradually restore charging power. For example, a CAN message ID 0x456 containing the target current value of 20A. The BMS sends the corresponding current adjustment commands from the second arithmetic progression to the external DC charger sequentially at preset time intervals (e.g., 1 second or 2 seconds). For example, a command to increase to 15A is sent first, followed by a waiting period, and then a command to increase to 20A is sent until the original fast charging current is finally restored. This achieves a step-by-step smooth current increase, avoiding the impact of sudden current changes on the battery or charging equipment. After the current recovery process is completed or the calibration data is confirmed to be effective, the BMS resets the currently recorded residual charge accumulation error (ΔSOC) to zero, establishing a new initial benchmark for the next round of SOC estimation and error accumulation monitoring.

[0079] By restoring the charging current in a stepwise manner and simultaneously clearing the accumulated error, it is possible to eliminate the estimation deviation within the current calibration cycle while ensuring charging safety and a smooth transition. This ensures the continuous stability of SOC estimation accuracy and achieves the technical effect of balancing fast charging efficiency and calibration accuracy, realizing periodic closed-loop calibration throughout the entire life cycle.

[0080] Optionally, in this embodiment 1, Figure 4 This is a flowchart illustrating an optional power battery SOC estimation method provided in Embodiment 1 of this application. Figure 4As shown, step S401 involves real-time calculation of the cumulative SOC error ΔSOC; step S402 involves determining whether the cumulative SOC error ΔSOC is ≥5%. If not, monitoring continues; if it is, DC charging condition identification is initiated. Step S403 involves determining whether the current state is DC charging. If not, monitoring continues; otherwise, step S404 is executed. Step S404 involves determining whether the SOC is within the 50%-55% range and the battery's lowest temperature is greater than a preset threshold T. If not, monitoring continues; otherwise, current adjustment is performed. Step S405 involves reducing the charging current to a preset calibration current of 10A. Step S406 involves monitoring the terminal voltage. Step S407 involves determining whether the voltage is within the 3.3-3.33V ramp range and stable. If not, monitoring continues; otherwise, step S408 is executed. Step S408 involves performing SOC calibration based on laboratory calibration data obtained from the voltage query. Step S409: After calibration, restore the original charging current and set the SOC cumulative error ΔSOC to zero, then start a new round of SOC cumulative error monitoring to achieve closed-loop accurate calibration.

[0081] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0082] In summary, the battery remaining power calibration method provided in this application collects the remaining power of the target battery in the target vehicle at preset intervals when a reset command is detected. The reset command is used to reset the accumulated error of the target battery's remaining power. The accumulated error is determined based on the remaining power of the target battery. The method then determines whether the target battery is currently in a calibration period based on the accumulated error, the target vehicle's operating condition information, the estimated remaining power of the target battery, and the battery temperature. If the target battery is in a calibration period, the charging current of the target battery is adjusted to a preset calibration current based on a current adjustment command. This preset calibration current is less than the target current corresponding to the charging condition. The estimated remaining power is calibrated based on the voltage value of the target battery within a preset time window to obtain the calibrated remaining power of the target battery. This method can periodically collect the remaining power and calculate the accumulated error in real time. When the detected error exceeds the threshold and the system is in DC fast charging mode, the current is actively reduced to the preset calibration current by issuing a current adjustment command. This eliminates the severe polarization effect caused by the large current and restores the slope region characteristics in the open-circuit voltage-remaining capacity curve. Even during fast charging without static conditions, the slope region voltage can be used to accurately calibrate the estimated remaining capacity value. This avoids the limitation of traditional methods in correcting accumulated errors under dynamic fast charging conditions, thus improving the accuracy of remaining capacity estimation for lithium iron phosphate batteries in fast charging scenarios. Therefore, it can solve the technical problem in related technologies where, during fast charging of lithium iron phosphate batteries, the slope region between the first and second plateau regions of the open-circuit voltage-remaining capacity curve disappears due to the large charging current, making traditional slow charging calibration methods unsuitable and resulting in inaccurate estimation of the remaining battery capacity. This achieves the technical effect of improving the accuracy and reliability of remaining capacity estimation for lithium iron phosphate batteries.

[0083] Example 2

[0084] This application also provides a battery remaining capacity calibration device. It should be noted that the battery remaining capacity calibration device of this application embodiment can be used to execute the battery remaining capacity calibration method provided in this application embodiment. The following describes the battery remaining capacity calibration device provided in this application embodiment.

[0085] According to an embodiment of this application, an apparatus for implementing the above-described method for calibrating the remaining battery power is also provided, the apparatus being deployed in a target vehicle. Figure 5 This is a schematic diagram of a battery remaining power calibration device according to Embodiment 2 of this application. Figure 5 As shown, the device includes: a data acquisition unit 501, a judgment unit 502, an adjustment unit 503, and a calibration unit 504.

[0086] Specifically, the acquisition unit 501 is used to acquire the remaining power of the target battery in the target vehicle at preset intervals when a reset command is detected, wherein the reset command is used to reset the accumulated error of the remaining power of the target battery.

[0087] The judgment unit 502 is used to determine the remaining power cumulative error based on the remaining power of the target battery, and to determine whether the target battery is currently in the remaining power calibration period based on the remaining power cumulative error, the operating condition information of the target vehicle, the estimated remaining power of the target battery and the battery temperature of the target battery.

[0088] The adjustment unit 503 is used to adjust the charging current of the target battery to a preset calibration current based on a current adjustment command when the target battery is in the remaining power calibration period, wherein the preset calibration current is less than the target current corresponding to the charging condition.

[0089] The calibration unit 504 is used to calibrate the estimated remaining power based on the voltage value of the target battery within a preset time window, so as to obtain the calibrated remaining power of the target battery.

[0090] The battery remaining power calibration device provided in this application embodiment, through the acquisition unit 501, acquires the remaining power of the target battery in the target vehicle at preset intervals when a reset command is detected. The reset command is used to reset the accumulated error of the target battery's remaining power. The judgment unit 502 determines the accumulated error of the remaining power based on the remaining power of the target battery, and determines whether the target battery is currently in a remaining power calibration period based on the accumulated error, the operating condition information of the target vehicle, the estimated remaining power value of the target battery, and the battery temperature of the target battery. When the target battery is in a remaining power calibration period, the adjustment unit 503 adjusts the charging current of the target battery to a preset calibration current based on a current adjustment command. The preset calibration current is less than the target current corresponding to the charging condition. The calibration unit 504 calibrates the estimated remaining power value based on the voltage value of the target battery within a preset time window to obtain the calibrated remaining power of the target battery. This device can periodically acquire data. The system calculates the remaining battery capacity and cumulative error in real time. When the error exceeds the threshold and the system is in DC fast charging mode, it actively issues a current adjustment command to reduce the large current to a preset calibration current, thereby eliminating the severe polarization effect caused by the large current and restoring the slope region characteristics in the open-circuit voltage-remaining capacity curve. Even during fast charging without static conditions, the slope region voltage can be used to accurately calibrate the estimated remaining battery capacity, avoiding the limitation of traditional methods in correcting cumulative errors under dynamic fast charging conditions. This achieves the technical effect of improving the remaining battery capacity estimation accuracy of lithium iron phosphate batteries in fast charging scenarios. Therefore, it can solve the technical problem in related technologies where, during fast charging of lithium iron phosphate batteries, the slope region between the first and second plateau regions of the open-circuit voltage-remaining capacity curve disappears due to the large charging current, making traditional slow charging calibration methods unsuitable and leading to inaccurate estimation of the remaining battery capacity. This achieves the technical effect of improving the remaining battery capacity estimation accuracy and reliability of lithium iron phosphate batteries.

[0091] Optionally, in the battery remaining power calibration device provided in Embodiment 2 of this application, the aforementioned judgment unit 502 includes: a statistics subunit, used to statistically analyze the remaining power of the target battery based on the coulomb integral error to obtain the remaining power cumulative error; a first acquisition subunit, used to acquire the operating condition information of the target vehicle when the detected remaining power cumulative error is greater than a preset cumulative error; a first judgment subunit, used to determine whether the target vehicle is in DC fast charging mode based on the operating condition information; and a second judgment subunit, used to determine whether the current time is for remaining power calibration based on the remaining power of the target battery and the battery temperature of the target battery when the target vehicle is in DC fast charging mode.

[0092] Optionally, in the battery remaining power calibration device provided in Embodiment 2 of this application, the second judgment subunit includes: a data acquisition module, used to determine the first remaining power of the target battery based on the battery management system of the target battery, and to acquire the lowest cell temperature of the target battery; a first judgment module, used to determine whether the first remaining power belongs to a first numerical range, wherein the lower limit of the first numerical range is less than the initial remaining power corresponding to the standard ramp zone of the lithium iron phosphate battery, and the upper limit of the first numerical range is less than the sum of the initial remaining power and the preset maximum cumulative error; a second judgment module, used to determine whether the lowest cell temperature is greater than a preset temperature, wherein the preset temperature is obtained experimentally based on the polarization characteristics and voltage stability of the battery at different temperatures; and a first determination module, used to determine that the current time is for remaining power calibration when the first remaining power value belongs to the first numerical range and the lowest cell temperature is greater than the preset temperature.

[0093] Optionally, in the battery remaining power calibration device provided in Embodiment 2 of this application, the first judgment subunit includes: a third judgment module, used to collect the bus signal of the target vehicle and determine whether the target vehicle is in a parked state based on the bus signal; a fourth judgment module, used to collect the connection status signal between the target vehicle and the external charging device when the target vehicle is in a parked state, and determine whether the target vehicle is in a charging connection state based on the connection status signal; an identification module, used to collect the charging current signal of the target vehicle when the target vehicle is in a charging connection state, and identify the current type and current amplitude based on the charging current signal; and a second determination module, used to determine that the target vehicle is in a DC fast charging condition when the current type is a DC signal and the current amplitude is greater than a preset amplitude.

[0094] Optionally, in the battery remaining capacity calibration device provided in Embodiment 2 of this application, the calibration unit 504 includes: a first determining subunit, used to acquire the charging current signal of the target battery after executing the current adjustment command, and determine the charging current and the charging current fluctuation amplitude based on the charging current signal; a second acquiring subunit, used to acquire the single-cell terminal voltage of the target battery based on a preset sampling period when the charging current is less than the preset calibration current and the charging current fluctuation amplitude is less than the preset amplitude; a second determining subunit, used to determine the current voltage of the target battery as the slope region characteristic voltage when it is detected that the single-cell terminal voltage is within a preset slope region voltage range and the voltage fluctuation amplitude of the single-cell terminal voltage is less than the preset amplitude; and a query subunit, used to query the calibration condition database based on the slope region characteristic voltage to obtain the calibrated remaining capacity, wherein the calibration condition database stores the mapping relationship between the voltage calibrated by the charge and discharge experiment for the preset calibration current and the remaining capacity.

[0095] Optionally, in the battery remaining power calibration device provided in Embodiment 2 of this application, the adjustment unit 503 includes: a third determining subunit, used to determine the first current corresponding to the target battery when it is in DC charging condition based on historical charging data; a first generating subunit, used to generate a first arithmetic sequence based on the first current and a preset calibration current; a second generating subunit, used to generate a first current adjustment command based on each value in the first arithmetic sequence; and a sending subunit, used to send the first current adjustment command to the DC charger of the external charging device through the battery management system of the target battery at preset intervals.

[0096] Optionally, in the battery remaining power calibration device provided in Embodiment 2 of this application, the device further includes: a first generation unit, used to calibrate the estimated remaining power value based on the voltage value of the target battery within a preset time window, and after obtaining the calibrated remaining power of the target battery, generate a second arithmetic sequence based on a preset calibration current and a charging current; a second generation unit, used to generate a second current adjustment command based on each value in the second arithmetic sequence; a sending unit, used to send the second current adjustment command to the DC charger of an external charging device through the battery management system of the target battery at preset intervals; and a processing unit, used to reset the accumulated error of the remaining power of the target battery.

[0097] It should be noted that the acquisition unit 501, judgment unit 502, adjustment unit 503, and calibration unit 504 mentioned above correspond to steps S201 to S204 in Embodiment 1. The two modules and their corresponding steps implement the same instances and application scenarios, but are not limited to the content disclosed in Embodiment 1. It should be noted that the above modules or units can be hardware or software components stored in memory (e.g., memory 104) and processed by one or more processors (e.g., processors 102a, 102b, ..., 102n). The above modules can also be part of a device and run in the computer terminal 10 provided in Embodiment 1.

[0098] Example 3

[0099] Embodiments of this application may provide an electronic device. Figure 6 This is a schematic diagram of a battery remaining power calibration electronic device provided according to Embodiment 3 of this application. Figure 6 As shown, the electronic device may include: one or more ( Figure 6 (Only one is shown) Processor 602, memory 604, memory controller, and peripheral interface, wherein the peripheral interface is connected to the radio frequency module, audio module and display.

[0100] The memory can be used to store software programs and modules, such as the program instructions / modules corresponding to the methods and apparatus in the embodiments of this application. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory, thereby implementing the above-described methods. The memory may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory may further include memory remotely located relative to the processor, and these remote memories can be connected to the terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0101] The processor can access information and applications stored in memory via a transmission device to execute the following steps: Upon detecting a reset command, the remaining charge of the target battery in the target vehicle is collected at preset intervals, wherein the reset command is used to reset the accumulated error of the target battery's remaining charge; the accumulated error of the remaining charge is determined based on the remaining charge of the target battery; based on the accumulated error of the remaining charge, the operating condition information of the target vehicle, the estimated remaining charge of the target battery, and the battery temperature of the target battery, it is determined whether the target battery is currently in a remaining charge calibration period; if the target battery is in a remaining charge calibration period, the charging current of the target battery is adjusted to a preset calibration current based on a current adjustment command, wherein the preset calibration current is less than the target current corresponding to the charging condition; the estimated remaining charge is calibrated based on the voltage value of the target battery within a preset time window to obtain the calibrated remaining charge of the target battery.

[0102] The processor can access information and applications stored in the memory via a transmission device to execute the following steps: determining the remaining power cumulative error based on the remaining power of the target battery; determining whether the target battery is currently in a remaining power calibration period based on the remaining power cumulative error, the target vehicle's operating condition information, the estimated remaining power of the target battery, and the target battery's battery temperature; including: statistically analyzing the remaining power of the target battery based on the coulomb integral error to obtain the remaining power cumulative error; collecting the target vehicle's operating condition information when the detected remaining power cumulative error is greater than a preset cumulative error; determining whether the target vehicle is in DC fast charging mode based on the operating condition information; and determining whether the current period is in a remaining power calibration period based on the remaining power of the target battery and the target battery temperature when the target vehicle is in DC fast charging mode.

[0103] The processor can access information and applications stored in the memory via a transmission device to execute the following steps: determining whether the current time is for remaining capacity calibration based on the remaining capacity and temperature of the target battery, including: determining the first remaining capacity of the target battery based on the battery management system of the target battery, and collecting the lowest cell temperature of the target battery; determining whether the first remaining capacity is within a first numerical range, wherein the lower limit of the first numerical range is less than the initial remaining capacity corresponding to the standard ramp zone of the lithium iron phosphate battery, and the upper limit of the first numerical range is less than the sum of the initial remaining capacity and the preset maximum cumulative error; determining whether the lowest cell temperature is greater than a preset temperature, wherein the preset temperature is obtained experimentally based on the polarization characteristics and voltage stability of the battery at different temperatures; and determining that the current time is for remaining capacity calibration if the first remaining capacity value is within the first numerical range and the lowest cell temperature is greater than the preset temperature.

[0104] The processor can access information and applications stored in the memory via a transmission device to execute the following steps: determining whether the target vehicle is in DC fast charging mode based on operating condition information, including: acquiring the target vehicle's bus signal and determining whether the target vehicle is in a parked state based on the bus signal; if the target vehicle is in a parked state, acquiring the connection status signal between the target vehicle and the external charging device and determining whether the target vehicle is in a charging connection state based on the connection status signal; if the target vehicle is in a charging connection state, acquiring the target vehicle's charging current signal and identifying the current type and current amplitude based on the charging current signal; if the current type is a DC signal and the current amplitude is greater than a preset amplitude, determining that the target vehicle is in DC fast charging mode.

[0105] The processor can access information and applications stored in the memory via a transmission device to execute the following steps: calibrating the estimated remaining capacity based on the voltage value of the target battery within a preset time window to obtain the calibrated remaining capacity of the target battery, including: after executing the current adjustment command, acquiring the charging current signal of the target battery, and determining the charging current and charging current fluctuation amplitude based on the charging current signal; when the charging current is less than the preset calibration current and the charging current fluctuation amplitude is less than the preset amplitude, acquiring the single-cell terminal voltage of the target battery based on a preset sampling period; when the single-cell terminal voltage is detected to be within the preset ramp voltage range and the voltage fluctuation amplitude of the single-cell terminal voltage is less than the preset amplitude, determining the current voltage of the target battery as the ramp characteristic voltage; querying the calibration condition database based on the ramp characteristic voltage to obtain the calibrated remaining capacity, wherein the calibration condition database stores the mapping relationship between the voltage calibrated by the charge and discharge experiment for the preset calibration current and the remaining capacity.

[0106] The processor can access information and applications stored in the memory via a transmission device to execute the following steps: adjusting the charging current of the target battery to a preset calibration current based on a current adjustment command, including: determining the first current corresponding to the target battery under DC charging conditions based on historical charging data; generating a first arithmetic sequence based on the first current and the preset calibration current; generating a first current adjustment command based on each value in the first arithmetic sequence; and sending the first current adjustment command to the DC charger of the external charging device through the battery management system of the target battery at preset intervals.

[0107] The processor can access information and applications stored in the memory via a transmission device to execute the following steps: After calibrating the estimated remaining capacity based on the voltage value of the target battery within a preset time window to obtain the calibrated remaining capacity of the target battery, the method further includes: generating a second arithmetic sequence based on a preset calibration current and a charging current; generating a second current adjustment command based on each value in the second arithmetic sequence; sending the second current adjustment command to the DC charger of an external charging device through the battery management system of the target battery at preset intervals; and resetting the accumulated error of the remaining capacity of the target battery.

[0108] This application provides a method for calibrating the remaining battery power. Upon detecting a reset command, the remaining battery power of a target battery in a target vehicle is collected at preset intervals. The reset command is used to reset the accumulated error of the remaining battery power. The accumulated error is determined based on the remaining battery power. The method then determines whether the target battery is currently in a calibration period based on the accumulated error, the vehicle's operating conditions, the estimated remaining battery power, and the battery temperature. If the target battery is in a calibration period, the charging current is adjusted to a preset calibration current based on a current adjustment command. This preset calibration current is less than the target current corresponding to the charging condition. The estimated remaining battery power is calibrated based on the target battery voltage within a preset time window to obtain the calibrated remaining battery power. This method allows for periodic collection of remaining battery power and real-time calculation of the accumulated error. When the error exceeds a threshold, the method can be activated. Furthermore, during DC fast charging, the system actively issues current adjustment commands to reduce the high current to a preset calibration current, thereby eliminating the severe polarization effect caused by the high current and restoring the slope region characteristics in the open-circuit voltage-remaining capacity curve. Even during fast charging without static conditions, the slope region voltage can be used to accurately calibrate the estimated remaining capacity, avoiding the limitation of traditional methods in correcting accumulated errors under dynamic fast charging conditions. This achieves the technical effect of improving the remaining capacity estimation accuracy of lithium iron phosphate batteries in fast charging scenarios. Therefore, it can solve the technical problem in related technologies where, during fast charging of lithium iron phosphate batteries, the slope region between the first and second plateau regions of the open-circuit voltage-remaining capacity curve disappears due to the large charging current, making traditional slow charging calibration methods unsuitable and leading to inaccurate estimation of the remaining battery capacity. This achieves the technical effect of improving the remaining capacity estimation accuracy and reliability of lithium iron phosphate batteries.

[0109] Those skilled in the art will understand that Figure 6 The structure shown is for illustrative purposes only. Electronic devices can also be smartphones, tablets, handheld computers, mobile internet devices (MIDs), PADs, and other terminal devices. Figure 6 This does not limit the structure of the aforementioned electronic device. For example, electronic devices may also include components that are more... Figure 6 The more or fewer components shown (such as network interfaces, display devices, etc.), or having the same Figure 6 The different configurations shown.

[0110] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing the hardware related to the terminal device. The program can be stored in a computer-readable storage medium, which may include: flash drive, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc.

[0111] Example 4

[0112] Embodiments of this application also provide a storage medium. Optionally, in this embodiment, the storage medium can be used to store the program code executed by the battery remaining power calibration method provided in Embodiment 1.

[0113] Optionally, in this embodiment, the storage medium may be located in any computer terminal in a group of computer terminals in a computer network, or in any mobile terminal in a group of mobile terminals.

[0114] This application also provides a computer program product, which, when executed on a data processing device, is adapted to perform a calibration method step for determining the remaining battery power.

[0115] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0116] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0117] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0118] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0119] Furthermore, the functional units 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 as a software functional unit.

[0120] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard drive, magnetic disk, or optical disk.

[0121] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for calibrating the remaining capacity of a battery, characterized in that, The method is applied to a target vehicle, and the method includes: Upon detecting a reset command, the remaining charge of the target battery in the target vehicle is collected at preset intervals, wherein the reset command is used to reset the accumulated error of the remaining charge of the target battery; The remaining power accumulation error is determined based on the remaining power of the target battery. Based on the remaining power accumulation error, the operating condition information of the target vehicle, the estimated remaining power of the target battery, and the battery temperature of the target battery, it is determined whether the target battery is currently in a period of remaining power calibration. When the target battery is in the remaining power calibration period, the charging current of the target battery is adjusted to a preset calibration current based on the current adjustment command, wherein the preset calibration current is less than the target current corresponding to the charging condition; The remaining power estimate is calibrated based on the voltage value of the target battery within a preset time window to obtain the calibrated remaining power of the target battery.

2. The method according to claim 1, characterized in that, The remaining power accumulation error is determined based on the remaining power of the target battery. Based on the remaining power accumulation error, the operating condition information of the target vehicle, the estimated remaining power of the target battery, and the battery temperature of the target battery, it is determined whether the target battery is currently in a state of remaining power calibration, including: The remaining charge of the target battery is statistically analyzed based on the coulomb integral error to obtain the cumulative error of the remaining charge. If the detected cumulative error of the remaining battery power is greater than the preset cumulative error, the operating condition information of the target vehicle is collected; Based on the aforementioned operating condition information, determine whether the target vehicle is in DC fast charging mode; When the target vehicle is in DC fast charging mode, the system determines whether it is time to calibrate the remaining charge based on the remaining charge and temperature of the target battery.

3. The method according to claim 2, characterized in that, Determining whether it is time to calibrate the remaining battery capacity based on the remaining battery capacity and the battery temperature of the target battery includes: The battery management system based on the target battery determines the first remaining charge of the target battery and collects the lowest cell temperature of the target battery. Determine whether the first remaining power belongs to a first numerical range, wherein the lower limit of the first numerical range is less than the initial remaining power corresponding to the standard slope zone of the lithium iron phosphate battery, and the upper limit of the first numerical range is less than the sum of the initial remaining power and the preset maximum cumulative error; Determine whether the minimum temperature of the battery cell is greater than a preset temperature, wherein the preset temperature is obtained experimentally based on the polarization characteristics and voltage stability of the battery at different temperatures; If the first remaining power value is within the first numerical range and the lowest temperature of the battery cell is greater than the preset temperature, it is determined that the current time is for remaining power calibration.

4. The method according to claim 2, characterized in that, Determining whether the target vehicle is in DC fast charging mode based on the aforementioned operating condition information includes: Collect the bus signal of the target vehicle, and determine whether the target vehicle is in a parked state based on the bus signal; When the target vehicle is in a parked state, the connection status signal between the target vehicle and the external charging device is collected, and the target vehicle is determined to be in a charging connection state based on the connection status signal. When the target vehicle is in a charging connection state, the charging current signal of the target vehicle is collected, and the current type and current amplitude are identified based on the charging current signal. If the current type is a DC signal and the current amplitude is greater than a preset amplitude, the target vehicle is determined to be in DC fast charging mode.

5. The method according to claim 1, characterized in that, The remaining power estimate is calibrated based on the voltage value of the target battery within a preset time window to obtain the calibrated remaining power of the target battery, including: After executing the current adjustment command, the charging current signal of the target battery is acquired, and the charging current and the charging current fluctuation amplitude are determined based on the charging current signal. When the charging current is less than the preset calibration current and the fluctuation range of the charging current is less than the preset range, the single-cell terminal voltage of the target battery is collected based on a preset sampling period. If the voltage of the single cell terminal is detected to be within a preset slope voltage range and the voltage fluctuation amplitude of the single cell terminal is lower than the preset amplitude, the current voltage of the target battery is determined as the slope characteristic voltage. The remaining charge after calibration is obtained by querying the calibration condition database based on the characteristic voltage of the ramp area. The calibration condition database stores the mapping relationship between the voltage calibrated by the charge and discharge experiment for the preset calibration current and the remaining charge.

6. The method according to claim 1, characterized in that, Adjusting the charging current of the target battery to a preset calibration current based on a current regulation command includes: The first current corresponding to the target battery under DC charging conditions is determined based on historical charging data; A first arithmetic sequence is generated based on the first current and the preset calibration current; A first current adjustment command is generated based on each value in the first arithmetic sequence; At preset intervals, the battery management system of the target battery sends the first current adjustment command to the DC charger of the external charging device.

7. The method according to claim 1, characterized in that, After calibrating the estimated remaining capacity based on the voltage value of the target battery within a preset time window to obtain the calibrated remaining capacity of the target battery, the method further includes: A second arithmetic sequence is generated based on the preset calibration current and the charging current; A second current adjustment command is generated based on each value in the second arithmetic sequence; At preset intervals, the target battery's battery management system sends the second current adjustment command to the DC charger of the external charging device. The accumulated error of the remaining power of the target battery is reset.

8. A device for calibrating the remaining power of a battery, characterized in that, The device is deployed in the target vehicle, and the device includes: The acquisition unit is used to acquire the remaining power of the target battery in the target vehicle at preset intervals when a reset command is detected, wherein the reset command is used to reset the accumulated error of the remaining power of the target battery; The judgment unit is used to determine the remaining power accumulation error based on the remaining power of the target battery, and to determine whether the target battery is currently in the remaining power calibration period based on the remaining power accumulation error, the operating condition information of the target vehicle, the estimated remaining power of the target battery, and the battery temperature of the target battery. An adjustment unit is used to adjust the charging current of the target battery to a preset calibration current based on a current adjustment command when the target battery is in the remaining power calibration period, wherein the preset calibration current is less than the target current corresponding to the charging condition. The calibration unit is used to calibrate the estimated remaining power based on the voltage value of the target battery within a preset time window, so as to obtain the calibrated remaining power of the target battery.

9. An electronic device, characterized in that, include: Memory, which stores executable programs; A processor for running the program, wherein the program, when running, performs the battery remaining power calibration method according to any one of claims 1 to 7.

10. A computer program product comprising computer instructions, characterized in that, When the computer instructions are executed by the processor, they implement the steps of the battery remaining power calibration method according to any one of claims 1 to 7.

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