Battery state of charge calibration method and related device

Abstract

The embodiment of the invention provides a battery state-of-charge calibration method and a related device, and relates to the technical field of batteries, and the method comprises the steps: obtaining the voltage and current collected at each sampling moment in the charging process of a battery; determining an abnormal time period in the charging process according to the voltage and / or the current, and correcting the voltage collected by each sampling node in the abnormal time period to obtain a first voltage collected by each sampling node in the abnormal time period; and calibrating the state of charge of the battery according to the first voltage, a second voltage corresponding to a non-abnormal time period and the current. By means of the method, the accuracy of battery SOC calibration is effectively improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery state of charge calibration method and related devices. Background Art

[0002] A battery's state of charge (SOC) is the ratio of its remaining capacity to its fully charged capacity, reflecting the battery's true state of charge. Currently, the ampere-hour integration method can be used to estimate battery SOC. However, due to accumulated errors from factors such as current sensor sampling errors and errors in the current available capacity, this estimated SOC deviates significantly from the actual value over time.

[0003] In related technologies, a capacity increment curve can be used to calibrate the estimated SOC. However, the capacity increment curve has strict requirements on the battery's current operating conditions and is difficult to adapt to complex and changeable battery operating conditions, resulting in poor accuracy of SOC calibration. Summary of the Invention

[0004] The embodiments of the present application provide a battery state of charge calibration method and related devices, which can effectively improve the accuracy of SOC calibration.

[0005] In a first aspect, an embodiment of the present application provides a battery state of charge calibration method, comprising:

[0006] Obtaining the voltage and current of the battery collected at each sampling moment during the charging process;

[0007] determining an abnormal period in the charging process according to the voltage and / or the current, and correcting the voltage collected by each sampling node during the abnormal period to obtain a first voltage collected by each sampling node during the abnormal period;

[0008] The battery state of charge is calibrated according to the first voltage, a second voltage corresponding to a non-abnormal period, and the current.

[0009] In some embodiments, determining the abnormal period in the charging process according to the voltage and / or the current includes:

[0010] When the voltage and / or the current meets a preset condition, determining that the battery is in a first abnormal period;

[0011] The preset conditions include any of the following:

[0012] The absolute value of the voltage difference between the current sampling moment and the previous sampling moment is greater than the first voltage threshold, and the voltage difference between the current sampling moment and the previous sampling moment, as well as the absolute value of the voltage difference between each sampling moment and the corresponding previous sampling moment in the subsequent N sampling moments, are not preset values; N is an integer greater than 1;

[0013] The absolute value of the current difference between the current at the current sampling moment and the subsequent M sampling moments is greater than the first current threshold; M is an integer greater than 1;

[0014] An absolute value of a current difference between a current sampling moment and a previous sampling moment, and an absolute value of a current difference between each of the subsequent K sampling moments and the corresponding previous sampling moment are greater than a second current threshold.

[0015] In some embodiments, determining the abnormal period in the charging process according to the voltage and / or the current includes:

[0016] If the absolute value of the voltage difference between the current sampling moment and the Lth sampling moment before the current sampling moment is greater than the first voltage threshold, and, within the time period corresponding to the P sampling moments before the current sampling moment and the Q sampling moments after the current sampling moment, the sum of the current differences between each sampling moment and the previous sampling moment is greater than the second current threshold and less than the third current threshold, it is determined that the battery is in the second abnormal period; L, P, and Q are all integers greater than 1.

[0017] In some embodiments, determining the abnormal period in the charging process according to the voltage and / or the current includes:

[0018] If the absolute value of the current at the current sampling moment and the subsequent X sampling moments is less than a third current threshold, it is determined that the battery is in a third abnormal period; X is an integer greater than 1.

[0019] In some embodiments, the correcting the voltage corresponding to the abnormal period to obtain the first voltage corresponding to the abnormal period includes:

[0020] Acquire a first target voltage at a last sampling moment before entering the abnormal period, and a second target voltage at a first sampling moment after the abnormal period ends;

[0021] obtaining a correction value according to the first target voltage and the second target voltage;

[0022] The voltage at each sampling moment in the abnormal period is corrected according to the correction value to obtain the first voltage.

[0023] In some embodiments, calibrating the battery state of charge according to the first voltage, the second voltage corresponding to the non-abnormal period, and the current includes:

[0024] Obtaining voltage differences between respective sampling moments according to the first voltage and the second voltage;

[0025] obtaining a capacity difference between each sampling moment according to the current;

[0026] The battery state of charge is calibrated according to the voltage difference and the capacity difference.

[0027] In some embodiments, calibrating the battery state of charge according to the voltage difference and the capacity difference includes:

[0028] Obtaining the ratio between the capacity difference and the voltage difference between each sampling moment;

[0029] Obtaining a capacity increment curve of the battery according to the ratio;

[0030] Obtaining a target trough point in the capacity increment curve;

[0031] The battery state of charge is calibrated according to the target valley point.

[0032] In some embodiments, obtaining a target trough point in the capacity increment curve includes:

[0033] Starting from the target point of the capacity increment curve, when a suspected peak point appears, if the difference between the ratios corresponding to the suspected peak point and the target point is greater than a preset difference, or if the ratio corresponding to the suspected peak point is greater than a preset peak threshold, then determining the suspected peak point as a peak point;

[0034] Searching backward from the peak point, when a suspected trough point appears, if the voltage of the suspected trough point is greater than the first voltage threshold and less than the second voltage threshold, and the difference between the ratio corresponding to the suspected trough point and the ratio corresponding to the previous sampling moment is greater than a preset value, and the difference between the ratio corresponding to the peak point and the ratio corresponding to the suspected trough point is greater than a preset threshold, then the suspected trough point is determined to be the target trough point.

[0035] In some embodiments, calibrating the battery state of charge according to the target valley point includes:

[0036] Obtain the first battery capacity at the current sampling moment and the second battery capacity at the target valley point;

[0037] obtaining a capacity compensation value according to the first battery capacity and the second battery capacity;

[0038] Obtaining a calibrated battery capacity according to the capacity compensation value and the estimated battery capacity at the target valley point;

[0039] A calibrated battery state of charge is obtained according to the calibrated battery capacity and the nominal capacity of the battery.

[0040] In some embodiments, the method further comprises:

[0041] For any sampling moment, if the voltage difference is greater than or equal to a preset difference, obtaining a ratio between the capacity difference and the voltage difference at the sampling moment;

[0042] If the voltage difference is less than the preset difference, the ratio at the previous sampling moment is used as the ratio corresponding to the sampling moment.

[0043] In a second aspect, the present application provides an electronic device, comprising: a memory and a processor;

[0044] The memory is used to store computer instructions; the processor is used to execute the computer instructions stored in the memory to implement any method in the first aspect.

[0045] In a third aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, and the computer program is executed by a processor to implement any one of the methods in the first aspect.

[0046] In a fourth aspect, the present application provides a computer program product, comprising a computer program, which implements any one of the methods in the first aspect when executed by a processor.

[0047] In a fifth aspect, an embodiment of the present application provides a vehicle, in which the electronic device as described in the second aspect is provided.

[0048] The battery state of charge calibration method and related device provided in the embodiments of the present application obtain the voltage and current collected by the battery at each sampling moment during the charging process; determine the abnormal period of the charging process based on the voltage and / or current, and correct the voltage collected by each sampling node during the abnormal period to obtain the first voltage collected by each sampling node during the abnormal period; and calibrate the battery state of charge based on the first voltage, the second voltage corresponding to the non-abnormal period, and the current. In the above method, by compensating and correcting the voltage during the abnormal period of the battery charging process, an accurate capacity increment curve drawn based on voltage is obtained, which effectively improves the accuracy of battery SOC calibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 A schematic diagram of a scenario provided for an embodiment of the present application;

[0050] Figure 2 A flow chart of a battery state of charge calibration method provided in an embodiment of the present application Figure 1 ;

[0051] Figure 3 A flow chart of a battery state of charge calibration method provided in an embodiment of the present application Figure 2 ;

[0052] Figure 4 A schematic structural diagram of a battery state of charge calibration device provided in an embodiment of the present application;

[0053] Figure 5 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0054] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0055] In the embodiments of the present application, words such as "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects, and do not limit their order. Those skilled in the art will understand that words such as "first" and "second" do not limit the quantity or execution order, and words such as "first" and "second" do not necessarily mean different.

[0056] It should be noted that in the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" or "for example" should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0057] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0058] Lithium iron phosphate||graphite batteries have become the choice of many users due to their advantages of low cost and high safety. The current mainstream SOC estimation method for lithium iron phosphate batteries is to calibrate the full-segment ampere-hour integration combined with calibration points.

[0059] Currently, the most commonly used method for selecting calibration points is the open-circuit voltage method. Due to the instability and nonlinear characteristics of batteries, the relationship between open-circuit voltage and SOC is not straightforward. Furthermore, temperature changes significantly affect open-circuit voltage, necessitating temperature compensation. Furthermore, because lithium iron phosphate batteries have two long plateaus, it is difficult to estimate the capacity calibration ampere-hour integral using the open-circuit voltage method in the middle period.

[0060] During battery charging or discharging, the rate of change of voltage is closely related to the chemical reactions within the battery, thus reflecting the battery's current state. A battery's incremental capacity curve provides key information about the battery's current state by analyzing the relationship between voltage and capacity during the charge and discharge process. The incremental capacity curve typically uses voltage as the horizontal axis and incremental capacity (dQ / dV) as the vertical axis. The peaks and valleys on the curve correspond to the reaction points of phase transitions during the battery's charge and discharge process. These characteristic points can help identify different charge and discharge stages of the battery and monitor its health.

[0061] Therefore, by recording the battery's charging process at a certain temperature and rate to obtain a capacity increment curve, the difficulty in estimating the mid-stage SOC of lithium iron phosphate batteries can be solved. This method not only improves battery efficiency and safety, but also helps extend the battery life, which is of great significance to the development of energy storage BMS.

[0062] However, for energy storage batteries with variable working environments and complex working conditions, it is very difficult to estimate SOC using the capacity increment curve. First, in actual applications, batteries will experience changes in temperature, charge and discharge rates, and usage frequency, and these factors will affect the charge and discharge characteristics of the battery. Secondly, the frequent rate switching during charging causes drastic voltage changes. After the capacity increment curve is drawn, there are many peaks and it is difficult to capture the real trough point. Most of the current methods for using the capacity increment curve to estimate SOC require constant current conditions, which are not suitable for energy storage battery applications. Or they use fitting, prediction and other methods to improve the integrity of the capacity increment curve, which requires a large amount of prior experiments and computing power, and the cost is too high.

[0063] In view of this, an embodiment of the present application provides a battery state of charge calibration method, which identifies the working status of the battery during the battery charging process, and compensates and corrects the voltage at the moment of abnormal voltage change, thereby obtaining an accurate capacity increment curve drawn based on voltage, effectively improving the accuracy of battery SOC calibration.

[0064] The following specific embodiments are used to describe in detail the technical solution of the present application and how the technical solution of the present application solves the above technical problems. The following specific embodiments can be implemented independently or in combination with each other. For the same or similar concepts or processes, some embodiments may not be described in detail.

[0065] Figure 1 This is a schematic diagram of an application scenario of an embodiment of the present application, such as Figure 1 As shown, it includes a battery 1, a sensor 2 and a calibration device 3.

[0066] The sensor 2 is used to collect the voltage and current of the battery during operation.

[0067] In some embodiments, the sensor 2 may include a voltage sensor and a current sensor, or may be a sensor capable of measuring current and voltage.

[0068] In some embodiments, the sensor 2 may be integrated into the battery 1 or deployed outside the battery 2 , which is not limited in this embodiment of the present application.

[0069] The calibration device 3 may be a platform with data analysis and processing capabilities. For example, when the battery 1 is a power battery of a new energy vehicle, the calibration device 3 may be a battery management system (BMS) of the new energy vehicle.

[0070] Below Figure 1 Based on the embodiment shown, Figure 1The prediction device is the execution body, and the battery state of charge prediction method provided in the embodiment of the present application is described.

[0071] Figure 2 A flow chart of a battery state of charge calibration method provided in an embodiment of the present application Figure 1 ,like Figure 2 As shown, including:

[0072] S201: Obtain the voltage and current collected at each sampling moment during the charging process of the battery.

[0073] In some embodiments, during the battery charging process, the calibration device may receive the voltage and current of the battery collected by the sensor at each sampling moment (e.g., once per second). The voltage and current of the battery may refer to the charging voltage and charging current of the battery.

[0074] In some embodiments, the calibration device can determine whether the battery is in a charging state based on the received battery current. If the battery is determined to be in a charging state, the step of obtaining the voltage and current of the battery during the charging process is performed. For example, the calibration device can determine that the battery is in a charging state based on the absolute value of the current at the current sampling moment and the current at the subsequent Q (e.g., 19) sampling moments being greater than a preset charging current threshold.

[0075] S202: Determine an abnormal period in the charging process according to the voltage and / or the current, and correct the voltage corresponding to the abnormal period to obtain a first voltage corresponding to the abnormal period.

[0076] In some embodiments, the abnormal period during the charging process may refer to a period during the charging process that causes a rapid change in voltage.

[0077] The calibration device can identify abnormal periods in battery charging by determining whether the voltage and / or current collected at each sampling moment meet a preset determination strategy based on the voltage and current collected at each sampling moment.

[0078] In some embodiments, when the calibration device obtains the voltage and current collected at each sampling moment, the voltage and current collected at each sampling moment may be grouped in a preset processing manner to facilitate determination of the abnormal battery period.

[0079] For example, for each sampling moment, an array may be divided, and the array includes:

[0080] 1. The current value collected at this sampling moment, and the current values collected at the subsequent Q (for example, 19) sampling moments.

[0081] 2. The voltage value collected at the sampling moment and the voltage values collected at the previous P (for example, 50) sampling moments.

[0082] 3. The voltage difference between the sampling moment and the previous sampling moment, and the voltage differences between the subsequent Q (for example, 19) sampling moments and their corresponding previous moments.

[0083] The following describes how to determine if the battery is in an abnormal period:

[0084] In a possible implementation, when the voltage and / or the current meets a preset condition, it is determined that the battery is in a first abnormal period.

[0085] The preset conditions include any of the following:

[0086] 1. The absolute value of the voltage difference between the current sampling moment and the previous sampling moment is greater than a first voltage threshold, and the voltage difference between the current sampling moment and the previous sampling moment, as well as the absolute value of the voltage difference between each sampling moment and the corresponding previous sampling moment in the subsequent N sampling moments, are not preset values; where N is an integer greater than 1.

[0087] For example, if the absolute value of the voltage difference U1-U0 between the voltage U1 collected at the current sampling moment and the voltage U0 collected at the previous sampling moment is greater than the first voltage threshold, and the absolute value of the voltage difference U1-U0, as well as the voltage difference at each of the five subsequent sampling moments, is non-zero, then it can be determined that the battery has entered the first abnormal period. The first abnormal period can be defined as a situation where the battery current experiences a large and gradual change.

[0088] Optionally, in order to improve the accuracy of determining the first abnormal period, the voltage difference may be a smoothed voltage difference, that is, a voltage difference obtained by filtering the acquired voltages of each sampling node.

[0089] 2. The absolute value of the current difference between the current at the current sampling moment and the subsequent M sampling moments is greater than the first current threshold; M is an integer greater than 1.

[0090] For example, if the absolute value of the difference between the current I1 collected at the current sampling moment and the current at any of the subsequent 10 sampling nodes is greater than the first current threshold, it can be determined that the battery has entered the first abnormal period.

[0091] 3. The absolute value of the current difference between the current sampling moment and the previous sampling moment, and the absolute value of the current difference between each of the subsequent K sampling moments and the corresponding previous sampling moment are greater than the second current threshold.

[0092] For example, if the absolute value of the difference between the current I1 collected at the current sampling moment and the current I0 collected at the previous moment, and the absolute value of the difference between the current I1 collected at the current sampling moment and the current of any of the subsequent three sampling nodes are both greater than the second current threshold, it can be determined that the battery has entered the first abnormal period.

[0093] In one possible implementation, if the absolute value of the voltage difference between the current sampling moment and the Lth sampling moment before the current sampling moment is greater than a first voltage threshold, and, within a time period corresponding to the P sampling moments before the current sampling moment and the Q sampling moments after the current sampling moment, the sum of the current differences between each sampling moment and the previous sampling moment is greater than a second current threshold and less than a third current threshold, it is determined that the battery is in a second abnormal period; and L, P, and Q are all integers greater than 1.

[0094] For example, when the absolute value of the voltage difference between the current sampling moment and the 20th sampling moment before the current sampling moment is greater than the first voltage threshold, if the sum of the current differences between the current at any sampling moment and the previous sampling moment during the 50 sampling moments before the current sampling moment and the 19 sampling moments after the current sampling moment is greater than the second current threshold and less than the third current threshold, the battery is determined to be in a second abnormal period. The second abnormal period can be defined as the battery being charged with a small, gradual change in current.

[0095] In a possible implementation, if the absolute value of the current at the current sampling moment and the subsequent X sampling moments is less than a third current threshold, it is determined that the battery is in a third abnormal period; X is an integer greater than 1.

[0096] For example, if the absolute value of the current at the current sampling moment and the subsequent 19 sampling moments is less than the third current threshold, it is determined that the battery is in a third abnormal period. The third abnormal period can be defined as the battery being in a static state.

[0097] When the calibration device determines that the battery is in any abnormal period, the voltages collected by each sampling node during the abnormal period can be compensated using a preset voltage compensation value to obtain a first compensated voltage at each sampling node during the abnormal period. For example, each abnormal period can last for a period of time, which can be predefined in the calibration device.

[0098] S203: Calibrate the battery state of charge according to the first voltage, the second voltage corresponding to the non-abnormal period, and the current.

[0099] In some embodiments, the second voltage corresponding to the non-abnormal period may refer to the voltage collected at each sampling moment except the abnormal period.

[0100] The calibration device may obtain the voltage difference between each sampling node according to the first voltage and the second voltage, and determine the capacity difference between each sampling node according to the current, and then calibrate the SOC.

[0101] Exemplarily, a voltage difference between each sampling moment is obtained based on the first voltage and the second voltage; a capacity difference between each sampling moment is obtained based on the current; and the battery state of charge is calibrated based on the voltage difference and the capacity difference.

[0102] For example, the voltage difference may satisfy the following formula:

[0103] ΔV=V1-V0

[0104] Where V1 is the voltage collected at the current sampling moment, and V0 is the voltage collected at the previous sampling moment. The capacity difference can satisfy the following formula:

[0105] ΔQ=I*Δt

[0106] Where I is the current, and Δt is the time interval between the current sampling moment and the previous sampling moment.

[0107] After obtaining the capacity difference and voltage difference at each sampling moment, the capacity increment data corresponding to each sampling moment can be obtained.

[0108] For example, the capacity increment data (DQ / DV) may satisfy the following formula:

[0109]

[0110] After acquiring the capacity increment data of each sampling node, the calibration device draws a capacity increment curve of the battery based on the capacity increment data, and calibrates the charging device of the battery based on the capacity increment curve.

[0111] The battery state-of-charge calibration method provided in an embodiment of the present application obtains the voltage and current collected by the battery at each sampling moment during the charging process; determines the abnormal period of the charging process based on the voltage and / or current, and corrects the voltage collected by each sampling node during the abnormal period to obtain a first voltage collected by each sampling node during the abnormal period; and calibrates the battery state of charge based on the first voltage, a second voltage corresponding to the non-abnormal period, and the current. By compensating and correcting the voltage during the abnormal period of the battery charging process, an accurate capacity increment curve based on voltage is obtained, effectively improving the accuracy of battery SOC calibration.

[0112] Below Figure 2 Based on the embodiment shown, combined Figure 3The battery state of charge calibration method provided in the embodiment of the present application is further described.

[0113] Figure 3 A flow chart of a battery state of charge calibration method provided in an embodiment of the present application Figure 2 ,like Figure 3 As shown, including:

[0114] S301: Obtain the voltage and current collected at each sampling moment during the charging process of the battery.

[0115] S302: Determine an abnormal period in the charging process according to the voltage and / or the current.

[0116] In the embodiment of the present application, the specific implementation method of steps S301 and S302 is the same as Figure 2 The implementation method shown in S201 in the illustrated embodiment is similar and will not be repeated here.

[0117] S303 : Acquire a voltage correction value for the abnormal period, and correct the voltage at each sampling moment in the abnormal period according to the correction value to obtain the first voltage.

[0118] Exemplarily, a first target voltage at the last sampling moment before entering the abnormal period and a second target voltage at the first sampling moment after the abnormal period are obtained; and a correction value is obtained based on the first target voltage and the second target voltage.

[0119] For example, sampling moment A is the last sampling moment before the abnormal period, and the collected charging voltage is UA. Sampling node B is the first sampling moment after the abnormal period ends, and the collected charging voltage is UB. The voltage difference between the two sampling nodes is UA-UB.

[0120] For each sampling moment included in the abnormal period, the voltage difference may be subtracted from the charging voltage collected at each sampling moment to obtain the compensated first voltage of each sampling node in the abnormal period.

[0121] S304: Acquire capacity increment data corresponding to each sampling moment, and determine a capacity increment curve of the battery based on the capacity increment data.

[0122] In some embodiments, when the first voltage and the second voltage are obtained, the Figure 2 The formula in the embodiment shown obtains the voltage difference ΔV at each sampling moment, and, based on the current Figure 2The formula in the embodiment shown is used to obtain the capacity difference ΔQ at each sampling moment, and the ratio between the capacity difference ΔQ and the pressure difference ΔV at each sampling node is used as the capacity increment data corresponding to each sampling node.

[0123] When the capacity increment data at each sampling moment is obtained, a curve may be drawn to determine the capacity increment curve of the battery.

[0124] In some embodiments, to improve the efficiency of acquiring incremental capacity data, incremental capacity data may be calculated once when a significant change occurs in the charging voltage.

[0125] Exemplarily, for any sampling moment, if the voltage difference is greater than or equal to a preset difference, the ratio between the capacity difference and the voltage difference at the sampling moment is obtained; if the voltage difference is less than the preset difference, the ratio at the previous sampling moment is used as the ratio corresponding to the sampling moment.

[0126] For example, for sampling node A and its previous sampling node B, if the voltage change (UA-UB, also called the voltage difference) between the voltage UA collected by sampling node A and the voltage UB collected by sampling node B is greater than or equal to a preset change (e.g., 3 millivolts), then the capacity increment data corresponding to the sampling node A is calculated based on the voltage change between the voltage UA collected by sampling node A and the voltage collected by sampling node B and the corresponding capacity change.

[0127] For sampling node A, if the voltage difference (UA - UB, also known as the voltage differential) between the voltage UA sampled at sampling node A and the voltage UB sampled at sampling node B is less than a preset difference (e.g., 3 millivolts), the capacity increment data corresponding to sampling node B can be used as the capacity increment data for node A. By using the capacity increment data of the previous node at a node with a smaller voltage change, the efficiency of acquiring capacity increment data is improved.

[0128] S305: Obtain a target trough point in the capacity increment curve.

[0129] In some embodiments, when the capacity increment curve is obtained, a valley can be found in the curve to determine the target valley point.

[0130] Exemplarily, the search is started from the target point of the capacity increment curve. When a suspected peak point appears, if the difference between the ratios corresponding to the suspected peak point and the target point is greater than a preset difference, or if the ratio corresponding to the suspected peak point is greater than a preset peak threshold, the suspected peak point is determined to be a peak point.

[0131] Searching backward from the peak point, when a suspected trough point appears, if the voltage of the suspected trough point is greater than the first voltage threshold and less than the second voltage threshold, and the difference between the ratio corresponding to the suspected trough point and the ratio corresponding to the previous sampling moment is greater than a preset value, and the difference between the ratio corresponding to the peak point and the ratio corresponding to the suspected trough point is greater than a preset threshold, then the suspected trough point is determined to be the target trough point.

[0132] The target point may be a point at the front of the capacity increment curve, for example, a point corresponding to the 70th sampling moment, or a starting point when the curve begins to rise.

[0133] Starting from the starting point and searching backward, when the curve transitions from ascending to descending, the corresponding point can be regarded as a suspected peak point. The difference between the DQ / DV of the suspected peak point and the DQ / DV of the target point is determined to be greater than a preset difference. If so, the suspected peak point is determined to be the actual peak point. Alternatively, the DQ / DV of the suspected peak point is determined to be greater than a preset peak threshold. If so, the suspected peak point is determined to be the actual peak point.

[0134] After determining the peak point, search backward from the peak point. If there is a transition from falling to rising, the corresponding transition point can be used as a suspected trough point, and it is judged whether the voltage of the suspected trough point is greater than the first voltage threshold and less than the second voltage threshold, and whether the DQ / DV of the suspected trough point and the DQ / DV of the point corresponding to the previous sampling moment are greater than the preset value, and whether the DQ / DV of the suspected trough point and the DQ / DV of the peak point are greater than the preset threshold. If the above three conditions are met, the suspected trough point can be determined as the target trough point.

[0135] It should be understood that the various thresholds, preset values, and preset thresholds mentioned above can be set according to actual needs, and the embodiments of the present application do not limit this.

[0136] S306: Calibrate the battery state of charge according to the target valley point.

[0137] In some embodiments, after the target valley point is obtained, the state of charge of the battery may be calibrated based on the state of charge at the valley point.

[0138] Exemplarily, the first battery capacity at the current sampling moment and the second battery capacity at the target valley point are obtained; a capacity compensation value is obtained based on the first battery capacity and the second battery capacity; a calibrated battery capacity is obtained based on the capacity compensation value and the estimated battery capacity at the target valley point; and a calibrated battery state of charge is obtained based on the calibrated battery capacity and the nominal capacity of the battery.

[0139] The current sampling moment is the latest sampling moment after the trough point is determined. The first battery capacity at the current sampling moment and the second battery capacity at the target trough point can be obtained by the ampere-hour integration method. Specific implementation methods can refer to those in the prior art.

[0140] The compensation capacity may be a capacity difference between the first battery capacity and the second battery capacity. The estimated battery capacity at the target valley point may be a true value of the battery capacity at the valley point determined based on the battery characteristics.

[0141] The calibrated battery capacity may be the sum of the true value of the battery capacity at the valley point and the compensation capacity.

[0142] When the calibration module obtains the calibrated battery capacity, the ratio between the calibrated battery capacity and the nominal capacity of the battery may be used as the SOC of the calibrated battery at the current sampling moment.

[0143] In summary, the battery state of charge calibration method provided in the embodiment of the present application, by correcting the voltage during the abnormal period during the charging process, not only avoids the interference of abnormal voltage data on the capacity increment curve caused by current mutation, but also effectively ensures the consistency and analyzability of the obtained capacity increment data by realigning the voltage-time curve after restoration to normal, and uses the trend combined with the voltage interval method to search for the characteristic points of the capacity increment curve. The setting of the voltage interval is predetermined according to the characteristics of the battery, and takes into account the performance of the battery under different working conditions. By comparing the voltage at the position where the characteristic point of the capacity increment curve appears with these preset voltage intervals, the rationality of the characteristic point can be further judged, thereby effectively improving the accuracy of SOC calibration.

[0144] Based on the above embodiments, an embodiment of the present application further provides a battery state of charge calibration device.

[0145] Figure 4 A schematic diagram of the structure of the battery state of charge calibration device 40 provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, including:

[0146] The acquisition module 401 is configured to acquire the voltage and current collected at each sampling moment during the charging process of the battery.

[0147] The correction module 402 is configured to determine an abnormal period in the charging process based on the voltage and / or the current, and correct the voltage collected by each sampling node during the abnormal period to obtain a first voltage collected by each sampling node during the abnormal period.

[0148] The calibration module 403 is configured to calibrate the battery state of charge according to the first voltage, the second voltage corresponding to the non-abnormal period, and the current.

[0149] In some embodiments, the correction module 402 is further configured to determine that the battery is in a first abnormal period when the voltage and / or the current meets a preset condition.

[0150] The preset conditions include any of the following:

[0151] The absolute value of the voltage difference between the current sampling moment and the previous sampling moment is greater than the first voltage threshold, and the voltage difference between the current sampling moment and the previous sampling moment, as well as the absolute value of the voltage difference between each sampling moment and the corresponding previous sampling moment in the subsequent N sampling moments are not preset values; where N is an integer greater than 1.

[0152] The absolute value of the current difference between the current at the current sampling moment and the subsequent M sampling moments is greater than the first current threshold; M is an integer greater than 1.

[0153] An absolute value of a current difference between a current sampling moment and a previous sampling moment, and an absolute value of a current difference between each of the subsequent K sampling moments and the corresponding previous sampling moment are greater than a second current threshold.

[0154] In some embodiments, the correction module 402 is further used to determine that the battery is in a second abnormal period when the absolute value of the voltage difference between the current sampling moment and the Lth sampling moment before the current sampling moment is greater than the first voltage threshold, and, within the time period corresponding to the P sampling moments before the current sampling moment and the Q sampling moments after the current sampling moment, the sum of the current differences between each sampling moment and the previous sampling moment is greater than the second current threshold and less than the third current threshold; the L, the P, and the Q are all integers greater than 1.

[0155] In some embodiments, the correction module 402 is further configured to determine that the battery is in a third abnormal period if the absolute value of the current at the current sampling moment and at subsequent X sampling moments is less than a third current threshold, where X is an integer greater than 1.

[0156] In some embodiments, the calibration module 403 is also used to obtain the first target voltage at the last sampling moment before entering the abnormal period, and the second target voltage at the first sampling moment after the end of the abnormal period; obtain a correction value based on the first target voltage and the second target voltage; and correct the voltage at each sampling moment in the abnormal period according to the correction value to obtain the first voltage.

[0157] In some embodiments, the calibration module 403 is further used to obtain the voltage difference between each sampling moment based on the first voltage and the second voltage; obtain the capacity difference between each sampling moment based on the current; and calibrate the battery state of charge based on the voltage difference and the capacity difference.

[0158] In some embodiments, the calibration module 403 is further used to obtain the ratio between the capacity difference and the voltage difference between each sampling moment; obtain the capacity increment curve of the battery according to the ratio; obtain the target valley point in the capacity increment curve; and calibrate the battery state of charge according to the target valley point.

[0159] In some embodiments, the calibration module 403 is further used to start searching from the target point of the capacity increment curve. When a suspected peak point appears, if the difference between the ratios corresponding to the suspected peak point and the target point is greater than a preset difference, or if the ratio corresponding to the suspected peak point is greater than a preset peak threshold, then the suspected peak point is determined to be a peak point; and search backward from the peak point. When a suspected trough point appears, if the voltage of the suspected trough point is greater than a first voltage threshold and less than a second voltage threshold, and the difference between the ratio corresponding to the suspected trough point and the ratio corresponding to the previous sampling moment is greater than a preset value, and the difference between the ratio corresponding to the peak point and the ratio corresponding to the suspected trough point is greater than a preset threshold, then the suspected trough point is determined to be the target trough point.

[0160] In some embodiments, the calibration module 403 is further used to obtain the first battery capacity at the current sampling moment and the second battery capacity at the target valley point; obtain a capacity compensation value based on the first battery capacity and the second battery capacity; obtain a calibrated battery capacity based on the capacity compensation value and the estimated battery capacity at the target valley point; obtain a calibrated battery state of charge based on the calibrated battery capacity and the nominal capacity of the battery.

[0161] In some embodiments, the calibration module 403 is also used to obtain the ratio between the capacity difference and the voltage difference at any sampling moment if the voltage difference is greater than or equal to a preset difference; if the voltage difference is less than the preset difference, use the ratio at the previous sampling moment as the ratio corresponding to the sampling moment.

[0162] The battery state of charge calibration device provided in the embodiment of the present application can execute the battery state of charge calibration method provided in any of the above embodiments, and its principles and technical effects are similar, which will not be repeated here.

[0163] It should be noted that it should be understood that the division of the various modules of the above device is only a division of logical functions. In actual implementation, they can be fully or partially integrated into one physical entity, or they can be physically separated. And these modules can all be implemented in the form of software called by processing elements; they can also all be implemented in the form of hardware; some modules can also be implemented in the form of software called by processing elements, and some modules can be implemented in the form of hardware. Each module can be a separately established processing element, or it can be integrated into a chip of the above device. In addition, it can also be stored in the memory of the above device in the form of program code, and called by a processing element of the above device to execute the functions of the above modules. In addition, these modules can be fully or partially integrated together, or they can be implemented independently. The processing element here can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each module above can be completed by the hardware integrated logic circuit in the processor element or software instructions.

[0164] Figure 5 This is a schematic diagram of the structure of the electronic device 50 provided in the embodiment of the present application, as shown in FIG. Figure 5 As shown, it includes: a transceiver 501, a processor 502, and a memory 503.

[0165] The processor 502 executes the computer-executable instructions stored in the memory, so that the processor 502 performs the solution in the above embodiment. The processor 502 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0166] The memory 503 is connected to the processor 502 via a system bus and implements communication therebetween. The memory 503 is used to store computer program instructions.

[0167] The transceiver 501 can receive data and send control instructions.

[0168] Optionally, the electronic device 50 may further include a communication interface to communicate and interact with an external or internal device through the communication interface. The external device may be, for example, a client (e.g., a mobile phone, a tablet). In a specific implementation, if the communication interface, the memory 503, and the processor 502 are implemented independently, the communication interface, the memory 503, and the processor 502 may be interconnected via a bus and communicate with each other.

[0169] The system bus can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, among others. The system bus can be divided into an address bus, a data bus, a control bus, and so on. For ease of illustration, the figure shows only one thick line, but this does not imply that there is only one bus or only one type of bus. Transceivers are used to enable communication between the database access device and other computers (e.g., clients, read-write libraries, and read-only libraries). Memory may include random access memory (RAM) and non-volatile memory.

[0170] Optionally, in a specific implementation, if the communication interface, the memory 503 and the processor 502 are integrated on a chip, the communication interface, the memory 503 and the processor 502 can complete communication through an internal interface.

[0171] An embodiment of the present application further provides a vehicle, wherein the electronic device described in any of the aforementioned embodiments is installed in the vehicle.

[0172] In an embodiment of the present application, a computer-readable storage medium is further provided, on which a computer program is stored. When the computer program is executed by a processor, the technical solution of the above-mentioned battery state of charge calibration method embodiment is implemented. The implementation principle and technical effect are similar and will not be repeated here.

[0173] In one possible implementation, a computer-readable medium may include random access memory (RAM), read-only memory (ROM), compact disc read-only memory (CD-ROM) or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium designed to carry or store the desired program code in the form of instructions or data structures and accessible by a computer. Moreover, any connection is appropriately referred to as a computer-readable medium. For example, if a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technologies (such as infrared, radio and microwave) are used to transmit software from a website, server or other remote source, the coaxial cable, fiber optic cable, twisted pair, DSL or wireless technologies such as infrared, radio and microwave are included in the definition of medium. Disk and disc as used herein include optical disc, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, where disks typically reproduce data magnetically, while optical discs reproduce data optically using lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0174] A computer program product is also provided in an embodiment of the present application, including a computer program. When the computer program is executed by a processor, the technical solution of the above-mentioned battery state of charge calibration method embodiment is implemented. Its implementation principle and technical effects are similar and will not be repeated here.

[0175] In the specific implementation of the above-mentioned terminal device or server, it should be understood that the processor can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in the embodiments of the present application can be directly implemented as a hardware processor, or can be implemented by a combination of hardware and software modules in the processor.

[0176] Those skilled in the art will appreciate that all or part of the steps of any of the above method embodiments may be accomplished by hardware associated with program instructions. The aforementioned program may be stored in a computer-readable storage medium, and when the program is executed, all or part of the steps of the above method embodiments are executed.

[0177] If the technical solution of the present application is implemented in the form of software and sold or used as a product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the technical solution of the present application can be embodied in the form of a software product, and the computer software product is stored in a storage medium and includes a computer program or several instructions. The computer software product enables a computer device (which can be a personal computer, server, network device or similar electronic device) to perform all or part of the steps of the method described in the embodiment of the present application.

[0178] It should be noted that for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that this application is not limited by the order of the actions described, because according to this application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in this specification are all optional embodiments, and the actions and modules involved are not necessarily required by this application.

[0179] It should be further noted that, although the various steps in the flowchart are shown in sequence as indicated by the arrows, these steps are not necessarily performed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps may be performed in other orders. Moreover, at least a portion of the steps in the flowchart may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily performed at the same time, but may be performed at different times. The execution order of these sub-steps or stages is not necessarily to be performed in sequence, but may be performed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0180] It should be understood that the above-described device embodiments are merely illustrative, and the device of the present application may also be implemented in other ways. For example, the division of units / modules in the above-described embodiments is merely a logical functional division, and actual implementations may employ other division methods. For example, multiple units, modules, or components may be combined or integrated into another system, or some features may be omitted or not implemented.

[0181] In addition, unless otherwise specified, the functional units / modules in the various embodiments of the present application may be integrated into a single unit / module, each unit / module may exist physically separately, or two or more units / modules may be integrated together. The aforementioned integrated units / modules may be implemented in the form of hardware or software program modules.

[0182] If the integrated unit / module is implemented in hardware, the hardware may be digital circuits, analog circuits, etc. The physical implementation of the hardware structure includes, but is not limited to, transistors, memristors, etc. Unless otherwise specified, the processor may be any appropriate hardware processor, such as a CPU, GPU, FPGA, DSP, and ASIC. Unless otherwise specified, the storage unit may be any appropriate magnetic storage medium or magneto-optical storage medium, such as resistive random access memory (RRAM), dynamic random access memory (DRAM), static random access memory (SRAM), enhanced dynamic random access memory (EDRAM), high-bandwidth memory (HBM), hybrid memory cube (HMC), etc.

[0183] If the integrated unit / module is implemented in the form of a software program module and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application, 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, which is stored in a memory and includes a number of instructions for enabling a computer device (which can be a personal computer, server or network device, etc.) to execute all or part of the steps of the various embodiments of the present application. The aforementioned memory includes various media that can store program codes, such as a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk.

[0184] In the above embodiments, the description of each embodiment has its own emphasis. For parts not described in detail in a particular embodiment, please refer to the relevant description of other embodiments. The technical features of the above embodiments can be combined in any way. To keep the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0185] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery state of charge calibration method, characterized in that: include: Obtaining the voltage and current of the battery collected at each sampling moment during the charging process; determining an abnormal period in the charging process according to the voltage and / or the current, and correcting the voltage collected by each sampling node during the abnormal period to obtain a first voltage collected by each sampling node during the abnormal period; The battery state of charge is calibrated according to the first voltage, a second voltage corresponding to a non-abnormal period, and the current.

2. The method according to claim 1, characterized in that The determining the abnormal period in the charging process according to the voltage and / or the current includes: When the voltage and / or the current meets a preset condition, determining that the battery is in a first abnormal period; The preset conditions include any of the following: The absolute value of the voltage difference between the current sampling moment and the previous sampling moment is greater than the first voltage threshold, and the voltage difference between the current sampling moment and the previous sampling moment, as well as the absolute value of the voltage difference between each sampling moment and the corresponding previous sampling moment in the subsequent N sampling moments, are not preset values; N is an integer greater than 1; The absolute value of the current difference between the current at the current sampling moment and the subsequent M sampling moments is greater than the first current threshold; M is an integer greater than 1; An absolute value of a current difference between a current sampling moment and a previous sampling moment, and an absolute value of a current difference between each of the subsequent K sampling moments and the corresponding previous sampling moment are greater than a second current threshold.

3. The method according to claim 1, characterized in that The determining the abnormal period in the charging process according to the voltage and / or the current includes: If the absolute value of the voltage difference between the current sampling moment and the Lth sampling moment before the current sampling moment is greater than the first voltage threshold, and, within the time period corresponding to the P sampling moments before the current sampling moment and the Q sampling moments after the current sampling moment, the sum of the current differences between each sampling moment and the previous sampling moment is greater than the second current threshold and less than the third current threshold, it is determined that the battery is in the second abnormal period; L, P, and Q are all integers greater than 1.

4. The method according to claim 1, wherein The determining the abnormal period in the charging process according to the voltage and / or the current includes: If the absolute value of the current at the current sampling moment and the subsequent X sampling moments is less than a third current threshold, it is determined that the battery is in a third abnormal period; X is an integer greater than 1.

5. The method according to any one of claims 1 to 4, characterized in that The correcting the voltage corresponding to the abnormal period to obtain a first voltage corresponding to the abnormal period includes: Acquire a first target voltage at a last sampling moment before entering the abnormal period, and a second target voltage at a first sampling moment after the abnormal period ends; obtaining a correction value according to the first target voltage and the second target voltage; The voltage at each sampling moment in the abnormal period is corrected according to the correction value to obtain the first voltage.

6. The method according to claim 5, characterized in that The calibrating the battery state of charge according to the first voltage, the second voltage corresponding to the non-abnormal period, and the current includes: Obtaining voltage differences between respective sampling moments according to the first voltage and the second voltage; obtaining a capacity difference between each sampling moment according to the current; The battery state of charge is calibrated according to the voltage difference and the capacity difference.

7. The method according to claim 6, characterized in that The calibrating the battery state of charge according to the voltage difference and the capacity difference includes: Obtaining the ratio between the capacity difference and the voltage difference between each sampling moment; Obtaining a capacity increment curve of the battery according to the ratio; Obtaining a target trough point in the capacity increment curve; The battery state of charge is calibrated according to the target valley point.

8. The method according to claim 7, characterized in that The obtaining of a target trough point in the capacity increment curve includes: Starting from the target point of the capacity increment curve, when a suspected peak point appears, if the difference between the ratios corresponding to the suspected peak point and the target point is greater than a preset difference, or if the ratio corresponding to the suspected peak point is greater than a preset peak threshold, then determining the suspected peak point as a peak point; Searching backward from the peak point, when a suspected trough point appears, if the voltage of the suspected trough point is greater than the first voltage threshold and less than the second voltage threshold, and the difference between the ratio corresponding to the suspected trough point and the ratio corresponding to the previous sampling moment is greater than a preset value, and the difference between the ratio corresponding to the peak point and the ratio corresponding to the suspected trough point is greater than a preset threshold, then the suspected trough point is determined to be the target trough point.

9. The method according to claim 8, characterized in that The calibrating the battery state of charge according to the target valley point includes: Obtain the first battery capacity at the current sampling moment and the second battery capacity at the target valley point; obtaining a capacity compensation value according to the first battery capacity and the second battery capacity; Obtaining a calibrated battery capacity according to the capacity compensation value and the estimated battery capacity at the target valley point; A calibrated battery state of charge is obtained according to the calibrated battery capacity and the nominal capacity of the battery.

10. The method according to claim 7, characterized in that The method further comprises: For any sampling moment, if the voltage difference is greater than or equal to a preset difference, obtaining a ratio between the capacity difference and the voltage difference at the sampling moment; If the voltage difference is less than the preset difference, the ratio at the previous sampling moment is used as the ratio corresponding to the sampling moment.

11. An electronic device, characterized in that: The electronic device includes: a processor, a transceiver, and a memory; the processor is communicatively connected to the transceiver and the memory respectively; The memory stores computer-executable instructions; The transceiver communicates and interacts with an external device; The processor executes the computer-executable instructions stored in the memory to implement the method according to any one of claims 1 to 10.

12. A computer-readable storage medium, characterized in that A computer program is stored thereon, and the computer program is executed by a processor to implement the method according to any one of claims 1 to 10.

13. A computer program product, characterized in that The invention comprises a computer program, which implements the method according to any one of claims 1 to 10 when the computer program is executed by a controller.

14. A vehicle, characterized in that: Comprising the electronic device as claimed in claim 11.

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