Battery SOC value estimation method and related device

Abstract

The present invention provides a battery SOC value estimation method and related device, the method comprising: according to the current charging rate of the battery, determining a first target spectrum map in a plurality of preset spectrum maps, for each spectrum map in the plurality of spectrum maps, the spectrum map corresponds to a constant rate, the spectrum map is obtained by correcting the initial spectrum map corresponding to the spectrum map according to the historical operation data of the battery, the initial spectrum map corresponding to the spectrum map is obtained by charging and discharging at the constant rate corresponding to the spectrum map, for all spectrum maps in the plurality of spectrum maps, the absolute value of the difference between the constant rate corresponding to the first target spectrum map and the current charging rate of the battery is the smallest; through the mapping relationship between the voltage value and the SOC value in the first target spectrum map, determining the SOC value corresponding to the current voltage value of the battery as the target SOC value. The present invention can improve the estimation accuracy of the SOC value.

Description

Technical Field

[0001] The present invention relates to the technical field of battery management, and in particular to a battery SOC value estimation method and related devices. Background Art

[0002] The state of charge (SOC) of a battery system and its components at all levels refers to the ratio of the remaining battery power to the rated power. The state of charge is a key indicator of whether the battery system can operate safely and reliably and whether it can be accurately managed and controlled. Accurately estimating the battery SOC is one of the most important functions of a battery management system (BMS).

[0003] However, because the battery is highly nonlinear in actual use, it is usually necessary to correct the SOC calculation value in real time through an optimization algorithm to ensure the accuracy of the SOC calculation. Among them, CCV (Constant current voltage) is one of the important correction methods.

[0004] The CCV curve is used to represent the corresponding relationship between the SOC of the battery and the measured voltage. The existing CCV correction method is to perform CCV correction based on the SOC value of the CCV curve corresponding to the voltage as the correction target value.

[0005] The prior art needs to rely on a preset CCV spectrum diagram for CCV correction. However, when used in an actual vehicle, using the preset CCV spectrum diagram for SOC correction will result in certain errors, which reduces the SOC calculation accuracy. Summary of the invention

[0006] In view of this, the present invention provides a battery SOC value estimation method and related devices, which can solve the problem of low estimation accuracy of battery SOC in the prior art.

[0007] In a first aspect, an embodiment of the present invention provides a method for estimating a battery SOC value, comprising:

[0008] According to the current charging rate of the battery, a first target map is determined from a plurality of preset map graphs, for each map graph in the plurality of map graphs, the map graph corresponds to a constant rate, the map graph is used to represent a mapping relationship between a battery voltage value and an SOC value, the map graph is obtained by correcting an initial map graph corresponding to the map graph according to historical operation data of the battery, the initial map graph is obtained by charging and discharging at a constant rate corresponding to the map graph, and for all map graphs in the plurality of map graphs, the absolute value of the difference between the constant rate corresponding to the first target map and the current charging rate of the battery is the smallest;

[0009] The SOC value corresponding to the current voltage value of the battery is determined by the mapping relationship between the voltage value and the SOC value in the first target spectrum diagram as the target SOC value.

[0010] In a possible implementation, for each map map, the process of correcting the initial map map corresponding to the map map by using the historical operation data of the battery includes:

[0011] Obtaining the accumulated charging ampere-hours of the battery after a complete charging process, and using the accumulated charging ampere-hours as the charging terminal ampere-hours, wherein the complete charging process is used to indicate that the battery is charged until the accumulated charging ampere-hours no longer change as the charging time increases;

[0012] Calculate the cumulative charging ampere-hour corresponding to each SOC value according to the charging terminal ampere-hour and the rated ampere-hour of the battery;

[0013] For each accumulated charging ampere-hour corresponding to the SOC value, determine the time when the battery is charged to the accumulated charging ampere-hour, and obtain the charge and discharge rate and voltage value of the battery at the time;

[0014] According to the charge and discharge rate of the battery at this moment, a second target spectrum map is determined from the multiple spectrum maps, and for all spectrum maps in the multiple spectrum maps, the absolute value of the difference between the constant rate corresponding to the second target spectrum map and the charge and discharge rate at this moment is the smallest;

[0015] According to the SOC value and the voltage value at the moment corresponding to the SOC value, the voltage value corresponding to the SOC value in the initial map corresponding to the second target map is corrected.

[0016] In a possible implementation, calculating the cumulative charging ampere-hour corresponding to each SOC value according to the charging terminal ampere-hour and the rated ampere-hour of the battery includes:

[0017] The accumulated charging ampere-hours corresponding to each SOC value are calculated according to a preset formula:

[0018] SOC n％ =Ah 末端 -(1-n%)Ah 额定

[0019] Where, 0≤n≤100, SOC n％ It is used to indicate the accumulated charging ampere-hour corresponding to SOC n%, Ah 末端 Ah is the terminal ampere-hour of charging. 额定 is the rated ampere-hour of the battery.

[0020] In a possible implementation, the one complete charging process is a complete charging process among m complete charging processes closest to the current moment before the current moment, m is a positive integer greater than or equal to 2, and for an SOC value in the second target map, if a voltage value corresponding to the SOC value is obtained in each charging process among the n complete charging processes, wherein the m complete charging processes include the n complete charging processes, then the method further includes:

[0021] The n voltage values ​​corresponding to the SOC value are averaged to obtain the voltage value corresponding to the SOC value in the second target map.

[0022] In a second aspect, an embodiment of the present invention provides a battery SOC value estimation device, including: a target spectrum diagram determination module and an SOC value determination module;

[0023] The target spectrum determination module is used to determine a first target spectrum from a plurality of preset spectrums according to the current charging rate of the battery, wherein for each spectrum in the plurality of spectrums, the spectrum corresponds to a constant rate, and the spectrum is used to represent a mapping relationship between a battery voltage value and an SOC value, and the spectrum is obtained by correcting an initial spectrum corresponding to the spectrum according to the historical operation data of the battery, and the initial spectrum is obtained by charging and discharging at a constant rate corresponding to the spectrum, and for all spectrums in the plurality of spectrums, the absolute value of the difference between the constant rate corresponding to the first target spectrum and the current charging rate of the battery is the smallest;

[0024] The SOC value determination module is used to determine the SOC value corresponding to the current voltage value of the battery as the target SOC value through the mapping relationship between the voltage value and the SOC value in the first target spectrum diagram.

[0025] In one possible implementation,

[0026] The target spectrum determination optical module is used for:

[0027] Obtaining the accumulated charging ampere-hours of the battery after a complete charging process, and using the accumulated charging ampere-hours as the charging terminal ampere-hours, wherein the complete charging process is used to indicate that the battery is charged until the accumulated charging ampere-hours no longer change as the charging time increases;

[0028] Calculate the cumulative charging ampere-hour corresponding to each SOC value according to the charging terminal ampere-hour and the rated ampere-hour of the battery;

[0029] For each accumulated charging ampere-hour corresponding to the SOC value, determine the time when the battery is charged to the accumulated charging ampere-hour, and obtain the charge and discharge rate and voltage value of the battery at the time;

[0030] According to the charge and discharge rate of the battery at this moment, a second target spectrum map is determined in the multiple spectrum maps, and for all the spectrum maps in the multiple spectrum maps, the absolute value of the difference between the constant rate corresponding to the second target spectrum map and the charge and discharge rate at this moment is the smallest;

[0031] According to the SOC value and the voltage value at the moment corresponding to the SOC value, the voltage value corresponding to the SOC value in the initial map corresponding to the second target map is corrected.

[0032] In a possible implementation, the target spectrum map determination module is used to:

[0033] The accumulated charging ampere-hours corresponding to each SOC value are calculated according to a preset formula:

[0034] SOC n％ =Ah 末端 -(1-n%)Ah 额定

[0035] Where, 0≤n≤100, SOC n％ It is used to indicate the accumulated charging ampere-hour corresponding to SOC n%, Ah 末端 Ah is the terminal ampere-hour of charging. 额定 is the rated ampere-hour of the battery.

[0036] In a possible implementation, the one complete charging process is a complete charging process among m complete charging processes closest to the current moment before the current moment, m is a positive integer greater than or equal to 2, and for an SOC value in the second target map, if a voltage value corresponding to the SOC value is obtained in each charging process of n complete charging processes, wherein the m complete charging processes include the n complete charging processes, the target map determination module is further used to:

[0037] The n voltage values ​​corresponding to the SOC value are averaged to obtain the voltage value corresponding to the SOC value in the second target map.

[0038] In a third aspect, an embodiment of the present invention provides a vehicle, comprising a control device, wherein the control device comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the method described in the first aspect or any possible implementation of the first aspect are implemented.

[0039] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method described in the first aspect or any possible implementation method of the first aspect are implemented.

[0040] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0041] The present invention corrects the voltage value in the spectrum diagram obtained by constant rate charge and discharge through the actual operating data of the battery, so that for any SOC value in the corrected spectrum diagram, the voltage value corresponding to the SOC value is the same as the voltage value corresponding to the SOC value under the actual operating state of the battery. Since the corrected spectrum diagram reflects the actual operating state of the battery, the battery target SOC value determined by the corrected spectrum diagram is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0043] Figure 1 is a flow chart of a method for estimating a battery SOC value provided by an embodiment of the present invention;

[0044] Figure 2 It is a structural schematic diagram of a battery SOC value estimation device provided by an embodiment of the present invention;

[0045] Figure 3 Schematic diagram of a control device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0046] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0047] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below in conjunction with the accompanying drawings.

[0048] See also Figure 1, which shows a flow chart of the implementation of the battery SOC value estimation method provided by an embodiment of the present invention, which is described in detail as follows:

[0049] In step 101, according to the current charging rate of the battery, a first target spectrum is determined from a plurality of preset spectrum maps. For each spectrum map in the plurality of spectrum maps, the spectrum map corresponds to a constant rate, and the spectrum map is used to represent a mapping relationship between a battery voltage value and an SOC value. The spectrum map is obtained by correcting an initial spectrum map corresponding to the spectrum map according to historical operation data of the battery, and the initial spectrum map is obtained by charging and discharging at a constant rate corresponding to the spectrum map. For all spectrum maps in the plurality of spectrum maps, the absolute value of the difference between the constant rate corresponding to the first target spectrum map and the current charging rate of the battery is the smallest.

[0050] The battery charge and discharge rate characterizes the magnitude of the battery operating current during the battery charge and discharge process. It is defined as the ratio of the battery charge and discharge current to the rated capacity. In practical applications, it is often represented by C. For example, if the battery with a rated capacity of 10Ah has a discharge current of 10A, the discharge rate is 1C.

[0051] The pulse spectrum in the embodiment of the present invention is a CCV pulse spectrum, which is used to indicate the correspondence between the measured voltage and the SOC value of the battery. Existing CCV pulse spectrums are all obtained by charging at a constant rate. For example, the pulse spectrum corresponding to 0.1C is the correspondence between the battery voltage and the SOC value obtained at a constant rate of 0.1C, and the pulse spectrum corresponding to 0.33C is the correspondence between the battery voltage and the SOC value obtained at a constant rate of 0.33C. In a possible implementation, the CCV pulse spectrum provided by the prior art may be in the form of the following Tables 1 and 2, wherein the following Table 1 is a CCV pulse spectrum obtained by a constant rate of 0.1C in the prior art, and the following Table 2 is a CCV pulse spectrum obtained by a constant rate of 0.33C in the prior art.

[0052] Table 1

[0053] SOC / % 0 5 10 20 30 40 50 60 70 Voltage / V 2.805 3.205 3.241 3.296 3.326 3.330 3.335 3.361 3.364 SOC / % 80 90 95 96 97 98 99 100 Voltage / V 3.366 3.370 3.374 3.376 3.377 3.383 3.410 3.650

[0054] Table 2

[0055] SOC / % 0 5 10 20 30 40 50 60 70 Voltage / V 2.736 3.231 3.272 3.328 3.352 3.355 3.363 3.388 3.393 SOC / % 80 90 95 96 97 98 99 100 Voltage / V 3.399 3.411 3.428 3.472 3.517 3.561 3.606 3.650

[0056] In another possible implementation, the CCV spectrum diagram provided by the prior art may also be a curve showing the battery voltage value changing with the battery SOC value, or a curve showing the battery SOC value changing with the battery voltage value, which is not limited in the implementation of the present invention.

[0057] However, in actual operation of the battery, the charging rate of the battery will change with different charging stages. For example, when a battery is charged to a SOC value of 90%, it is first charged at a charging rate of 0.3C, and then charged to a SOC value of 94%, it is charged at a charging rate of 0.12C.

[0058] The problems of the prior art are explained with actual data obtained during the actual operation of a battery. When the battery is charged to an SOC value of 97%, its actual corresponding voltage value is 3.387V. Since the charging rate of the battery at the moment of charging to an SOC value of 97% is 0.12C, which is closest to 0.1C, the voltage value corresponding to this moment is determined by the pulse spectrum corresponding to 0.1C. Combined with the above Table 1, if at this time, the SOC value obtained by looking up Table 1 with a measured voltage of 3.387V, that is, the CCV pulse spectrum obtained by a constant charging rate of 0.1C, is greater than 98% and less than 99%, that is, the obtained SOC estimated value is higher than the actual SOC value. Due to battery aging and other reasons, the preset pulse spectrum cannot reflect the corresponding relationship between the measured voltage and SOC in the current state of the battery, resulting in a certain error between the SOC estimated value determined by the CCV pulse spectrum obtained by looking up the constant current charging closest to the charging rate through the measured voltage of the battery and the current charging rate of the battery and the actual SOC value, which affects the estimation accuracy of the SOC value.

[0059] To solve this problem, in an embodiment of the present invention, according to the charging rate, voltage value and corresponding actual SOC value of the battery during the actual charging process, each preset initial pulse spectrum obtained by constant rate charging and discharging is corrected, and the current SOC value of the battery is determined by the corrected pulse spectrum and the current voltage value of the battery, fully considering the corresponding relationship between the measured voltage and SOC of the battery during the actual charging process, so as to obtain a more accurate SOC estimation value.

[0060] In a possible implementation, for each map map, the process of correcting the initial map map corresponding to the map map by using the historical operation data of the battery includes:

[0061] The cumulative charging ampere-hours of the battery after a complete charging process are obtained, and the cumulative charging ampere-hours are used as the charging terminal ampere-hours. The complete charging process is used to indicate that the battery is charged until the cumulative charging ampere-hours no longer change as the charging time increases; the cumulative charging ampere-hours corresponding to each SOC value are calculated according to the charging terminal ampere-hours and the rated ampere-hours of the battery; for the cumulative charging ampere-hours corresponding to each SOC value, the moment corresponding to the cumulative charging ampere-hours is determined, and the charge and discharge rate and voltage value of the battery at the moment are obtained; according to the charge and discharge rate of the battery at the moment, a second target spectrum is determined from a plurality of spectrum graphs, and for all spectrum graphs in the plurality of spectrum graphs, the absolute value of the difference between the constant rate corresponding to the second target spectrum graph and the charge and discharge rate at the moment is the smallest; according to the SOC value and the voltage value at the moment corresponding to the SOC value, the voltage value corresponding to the SOC value in the initial spectrum graph corresponding to the second target spectrum graph is corrected.

[0062] During the charging process of the battery, the cumulative charging ampere-hour corresponding to each moment can be obtained by the ampere-hour integration method. Through the ampere-hour integration method, the integral of the charging current and time is the cumulative charging ampere-hour. In the embodiment of the present invention, a curve of the cumulative charging ampere-hour of the battery obtained by the ampere-hour integration method over time during the charging process can be obtained. When the cumulative charging ampere-hour of the battery reaches the maximum value, the cumulative charging ampere-hour no longer changes with the extension of the charging time, indicating that the battery charging is complete. Through the curve of the cumulative charging ampere-hour over time, the maximum value of the cumulative charging ampere-hour in the charging process is obtained as the charging terminal ampere-hour.

[0063] After determining the terminal ampere-hour of the battery in this charging process, the cumulative charging ampere-hour corresponding to each SOC value is calculated according to the preset formula. The preset formula is:

[0064] SOC n％ =Ah 末端 -(1-n%)Ah 额定

[0065] Where n is 0 or a positive number greater than 0 and less than or equal to 100, SOC n％ It is used to indicate the accumulated charging ampere-hour corresponding to SOC n%, Ah 末端 Ah is the terminal ampere-hour of charging. 额定 is the rated ampere-hour of the battery.

[0066] In the embodiment of the present invention, in order to facilitate the distinction between various formulas, the above-mentioned preset formula may be referred to as the first formula.

[0067] As a highly complex nonlinear system, the SOC of lithium-ion batteries cannot be directly measured and can only be estimated through parameters such as battery terminal voltage, charge and discharge current, and internal resistance. Among them, the ampere-hour integration method, also known as the current integration method, is one of the SOC estimation methods for lithium-ion batteries. Its main idea is to measure the discharge current of the battery and integrate the current over time to calculate the amount of electricity discharged over a period of time, and then estimate the SOC of the battery. The calculation formula of the ampere-hour integration method is the second formula, which is:

[0068]

[0069] In the formula, SOC O is the initial SOC value of the battery, C N is the rated capacity of the battery, also known as the rated ampere-hour, and I is the charge and discharge current of the battery, where I is positive for charging and negative for discharging. Used to represent the integral of current and time, which is the cumulative charging ampere-hour from the start of charging of the battery to time t.

[0070] Taking the battery charging process as an example, at the end of charging, the accumulated charging ampere-hour no longer changes with time, that is, as t increases, It no longer increases. At this time, the SOC value reaches the maximum value, that is, SOC=100%.

[0071] Transforming the second formula, we get the following third formula:

[0072]

[0073] when It is used to represent the charging terminal ampere-hour. At this time, SOC = 100% = 1. The third formula can be transformed into the following fourth formula:

[0074] C N (1-SOC O )=Ah 末端

[0075] From the fourth formula, for example, assuming SOC O =30%, that is, the SOC value at the initial moment of charging is 30%, then the cumulative charging ampere-hours from 30% SOC to 100% SOC, that is, charging 70% SOC is the terminal charging ampere-hour Ah 末端 , namely Ah 末端 =70%×C N , due to C N With Ah 额定 The same meaning, both are used to indicate the rated ampere-hour of the battery, then Ah 末端 =70%×Ah 额定 , that is, Ah 额定 =Ah末端 ÷70%.

[0076] Assuming SOC O =30%, combined with the first formula, SOC n％ It is used to represent the cumulative charging ampere-hours when the SOC is n%. At this time, since the initial SOC has reached 30%, charging is carried out on this basis. n must be greater than 30. Then, combined with the fourth formula, the cumulative charging ampere-hours corresponding to charging to SOC n% should be the following fifth formula:

[0077]

[0078] Through the above derivation process, SOC n％ =Ah 末端 -(1-n%)Ah 额定

[0079] For ease of understanding, the above derivation process is based on SAC O = 30% as an example for derivation, SOC O The same derivation result can be obtained for any value of , and this embodiment of the present invention will not be described in detail.

[0080] For example, during a complete charging process, the maximum cumulative charging ampere-hour of the battery is 170.455Ah. By calculating through the above formula when n=97, the corresponding cumulative charging ampere-hour when the SOC is 97% is 164.935Ah. By looking for the curve of the cumulative charging ampere-hour changing with time, it is obtained that during this charging process, the cumulative charging ampere-hour corresponding to time t1 is 164.935Ah. The charging rate of the battery at time t1 is obtained, which is determined to be 0.12C, and the voltage value of the battery at time t1 is obtained, which is determined to be 3.387V.

[0081] Assume that the existing initial pulse spectra are the pulse spectra obtained by charging and discharging at a constant rate of 0.1C Figure 1 , the pulse spectrum obtained by charging and discharging at a constant rate of 0.33C Figure 2 The pulse spectrum obtained by charging and discharging at a constant rate of 0.5C Figure 3 , since the charging rate at time t1 is 0.12C, which is closest to 0.1C, at this time, if the initial pulse spectrum corresponding to 0.1C, that is, the pulse spectrum Figure 1 As shown in Table 1, the voltage 0.377V corresponding to SOC=97% in Table 1 is corrected to 0.387V.

[0082] Through the above method, each initial spectrum map is corrected according to the historical operation data of the battery to obtain a corrected spectrum map corresponding to each initial spectrum map. The first target spectrum map in the embodiment of the present invention is the corrected spectrum map.

[0083] A portion of the corrected 0.33C initial spectrum is shown in Table 3, and a portion of the corrected 0.1C initial spectrum is shown in Table 4. In Tables 3 and 4, the content represented by the row of accumulated charging ampere-hours is only the data required in the correction process. The spectrum after correction may include the content of this row or may not include the content of this row, and the implementation of the present invention is not limited to this.

[0084] Table 3

[0085] SOC / % 91 92 93 94 Charging rate 0.33C 0.33C 0.33C 0.33C Accumulated charging ampere-hours / Ah 153.895 155.735 157.575 159.415 Voltage / V 3.414 3.417 3.420 3.425

[0086] Table 4

[0087]

[0088]

[0089] The whole correction process is explained below with an example.

[0090] The preset initial spectrum includes 3, which are the spectrum obtained at a constant rate of 0.1C. Figure 1 , the pulse spectrum obtained at a constant rate of 0.33C Figure 2 And the pulse spectrum obtained at a constant rate of 0.5C Figure 3 .

[0091] In a complete charging process, the charging process includes 4 stages, first charging at 0.12C for half an hour, then charging at 0.3C for half an hour, then charging at 0.48C for half an hour, and finally charging at 0.14C for 10 minutes. This process is only an example and does not represent the actual charging process.

[0092] In the first charging stage, the charging rate is 0.12C and the pulse spectrum Figure 1 The corresponding 0.1C is closest, so the voltage value corresponding to each SOC value obtained from the charging data in this stage is used to correct the pulse spectrum Figure 1 The voltage value corresponding to the SOC value in;

[0093] In the second charging stage, the charging rate is 0.3C and the pulse spectrum Figure 2 The corresponding 0.33C is closest, so the voltage value corresponding to each SOC value obtained from the charging data in this stage is used to correct the pulse spectrum Figure 3 The voltage value corresponding to the SOC value in;

[0094] In the third charging stage, the charging rate is 0.48C and the pulse spectrum Figure 3 The corresponding 0.5C is closest, so the voltage value corresponding to each SOC value obtained from the charging data in this stage is used to correct the pulse spectrum Figure 3 The voltage value corresponding to the SOC value in;

[0095] In the fourth charging stage, the charging rate is 0.14C and the pulse spectrum Figure 1 The corresponding 0.1C is closest, so the voltage value corresponding to each SOC value obtained from the charging data in this stage is used to correct the pulse spectrum Figure 1 The voltage value corresponding to the SOC value.

[0096] When the battery is in the subsequent charging process, since the current change in each charging process is basically the same for the same battery, the current voltage value and the corrected pulse spectrum are closer to the actual state of the battery, and the obtained SOC value is more accurate.

[0097] For example, pulse spectrum Figure 1 When SOC=97%, the corresponding voltage value is 3.377V, and when the battery is actually charged to 97%, the corresponding voltage value is 3.387V. In the actual operation of the battery, when the battery voltage is 3.387V, it is judged by the charge rate of 0.12C that the pulse spectrum Figure 1 Determine the SOC value, the SOC value obtained is between 98% and 99%, which has a certain error from the true SOC value. Figure 1 In the figure, the voltage value corresponding to SOC=97% is 3.387V. When the battery is charged to 3.387V again and the charging rate is 0.12V, check the corrected pulse spectrum. Figure 1 The obtained SOC value is 97%, which is the same as the actual SOC value of the current battery, thereby improving the accuracy of SOC value estimation.

[0098] In a possible implementation, as the battery usage time increases, the battery will decay to a certain extent, and various indicators of the battery will also change to a certain extent. To ensure that the pulse spectrum obtained in the embodiment of the present invention is sufficiently accurate, in the embodiment of the present invention, the above-mentioned one complete charging process is a complete charging process in the m complete charging processes closest to the current moment before the current moment, and m is a positive integer greater than or equal to 2. For an SOC value in the second target pulse spectrum, if a voltage value corresponding to the SOC value is obtained in each charging process in the n complete charging processes, wherein the m complete charging processes include n complete charging processes, then the method further includes: averaging the n voltage values ​​corresponding to the SOC value to obtain the voltage value corresponding to the SOC value in the second target pulse spectrum. For example, five complete charging processes within two months before the current moment are obtained. In each charging process, for each SOC value, such as SOC=97%, the charging rate corresponding to the SOC value usually does not change. Combined with the above example, the charging rate is 0.12C when SOC=97%. In each charging process, a voltage value corresponding to SOC = 97% can be calculated. For example, the voltage value obtained when SOC = 97% in the first charging process is V1, the voltage value obtained when SOC = 97% in the second charging process is V2... The voltage value when SOC = 97% in the fifth charging process is V5, then the average value from V1 to V5 is calculated to determine the final pulse spectrum. Figure 1 The voltage value corresponding to SOC=97%.

[0099] In step 102, the SOC value corresponding to the current voltage value of the battery is determined as the target SOC value through the mapping relationship between the voltage value and the SOC value in the first target map.

[0100] Since the target map includes a mapping relationship between the battery voltage value and the SOC value, the SOC value corresponding to the voltage value can be determined through the mapping relationship and the current voltage value of the battery, and the SOC value is used as the target SOC value.

[0101] In a possible implementation, the modified map is shown in Table 3 and Table 4, which only includes a portion of the SOC values ​​and the voltage value corresponding to each SOC value. If the current voltage value does not belong to the voltage value included in the map, the SOC value corresponding to the current voltage value can be obtained as the target SOC value by linear interpolation.

[0102] In one possible implementation, the corrected pulse spectrum is a curve showing the battery voltage changing with the SOC value, or a curve showing the battery SOC value changing with the voltage value. A unique point can be determined on the curve based on the current voltage value of the battery, and the SOC value corresponding to the point is the target SOC value.

[0103] The present invention corrects the voltage value in the spectrum diagram obtained by constant rate charge and discharge through the actual operating data of the battery, so that for any SOC value in the corrected spectrum diagram, the voltage value corresponding to the SOC value is the same as the voltage value corresponding to the SOC value under the actual operating state of the battery. Since the corrected spectrum diagram reflects the actual operating state of the battery, the battery target SOC value determined by the corrected spectrum diagram is more accurate.

[0104] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0105] The following is an embodiment of the device of the present invention. For details not described in detail therein, reference may be made to the corresponding method embodiment described above.

[0106] Figure 2 The structure diagram of the battery SOC value estimation device provided by the embodiment of the present invention is shown. For the convenience of explanation, only the part related to the embodiment of the present invention is shown, which is described in detail as follows:

[0107] like Figure 2 As shown, the battery SOC value estimation device 2 includes: a target map determination module and an SOC value determination module;

[0108] a target spectrum determination module, used to determine a first target spectrum from a plurality of preset spectrums according to a current charging rate of the battery, wherein for each spectrum in the plurality of spectrums, the spectrum corresponds to a constant rate, and the spectrum is used to represent a mapping relationship between a battery voltage value and an SOC value, and the spectrum is obtained by correcting an initial spectrum corresponding to the spectrum according to historical operation data of the battery, and the initial spectrum is obtained by charging and discharging at a constant rate corresponding to the spectrum, and for all spectrums in the plurality of spectrums, the absolute value of the difference between the constant rate corresponding to the first target spectrum and the current charging rate of the battery is the smallest;

[0109] The SOC value determination module is used to determine the SOC value corresponding to the current voltage value of the battery as the target SOC value through the mapping relationship between the voltage value and the SOC value in the first target spectrum diagram.

[0110] The present invention corrects the voltage value in the spectrum diagram obtained by constant rate charge and discharge through the actual operating data of the battery, so that for any SOC value in the corrected spectrum diagram, the voltage value corresponding to the SOC value is the same as the voltage value corresponding to the SOC value under the actual operating state of the battery. Since the corrected spectrum diagram reflects the actual operating state of the battery, the battery target SOC value determined by the corrected spectrum diagram is more accurate.

[0111] In a possible implementation, the target spectrum map determination optical module is used to:

[0112] Obtain the cumulative charging ampere-hours of the battery after a complete charging process, and use the cumulative charging ampere-hours as the charging terminal ampere-hours. The complete charging process is used to indicate that the battery is charged until the cumulative charging ampere-hours no longer change as the charging time increases;

[0113] Calculate the cumulative charging ampere-hours corresponding to each SOC value based on the charging terminal ampere-hours and the rated ampere-hours of the battery;

[0114] For each SOC value corresponding to the accumulated charging ampere-hour, determine the time when the battery is charged to the accumulated charging ampere-hour, and obtain the charge and discharge rate and voltage value of the battery at the time;

[0115] According to the charge and discharge rate of the battery at that moment, a second target spectrum is determined from the plurality of spectrum maps, and for all spectrum maps in the plurality of spectrum maps, the absolute value of the difference between the constant rate corresponding to the second target spectrum map and the charge and discharge rate at that moment is the smallest;

[0116] According to the SOC value and the voltage value at the time corresponding to the SOC value, the voltage value corresponding to the SOC value in the initial map corresponding to the second target map is corrected.

[0117] In a possible implementation, the target spectrum map determination module is used to:

[0118] The accumulated charging ampere-hours corresponding to each SOC value are calculated according to the preset formula. The preset formula is:

[0119] SOC n％ =Ah 末端 -(1-n%)Ah 额定

[0120] Where, 0≤n≤100, SOC n％ It is used to indicate the accumulated charging ampere-hour corresponding to SOC n%, Ah 末端 Ah is the terminal ampere-hour of charging. 额定 is the rated ampere-hour of the battery.

[0121] In a possible implementation, a complete charging process is a complete charging process among m complete charging processes closest to the current moment before the current moment, where m is a positive integer greater than or equal to 2, and for an SOC value in the second target map, if a voltage value corresponding to the SOC value is obtained in each charging process among n complete charging processes, wherein the m complete charging processes include n complete charging processes, the target map determination module is further used to:

[0122] The n voltage values ​​corresponding to the SOC value are averaged to obtain the voltage value corresponding to the SOC value in the second target map.

[0123] The battery SOC value estimation device provided in this embodiment can be used to execute the above-mentioned battery SOC value estimation method embodiment, and its implementation principle and technical effect are similar, which will not be repeated in this embodiment.

[0124] An embodiment of the present invention further provides a vehicle, comprising a control device, Figure 3 Schematic diagram of a control device provided by an embodiment of the present invention. Figure 3 As shown, the control device 3 of this embodiment includes: a processor 30, a memory 31, and a computer program 32 stored in the memory 31 and executable on the processor 30. When the processor 30 executes the computer program 32, the steps in the above-mentioned battery SOC value estimation method embodiments are implemented, for example Figure 1 Alternatively, when the processor 30 executes the computer program 32, the functions of each module / unit in the above-mentioned device embodiments are realized, for example Figure 2 The functionality of module 21 is shown.

[0125] Exemplarily, the computer program 32 may be divided into one or more modules / units, which are stored in the memory 31 and executed by the processor 30 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, which are used to describe the execution process of the computer program 32 in the control device 3.

[0126] The control device 3 may be a control device / module / chip / device installed on the vehicle. The control device 3 may include, but is not limited to, a processor 30 and a memory 31. Those skilled in the art will appreciate that Figure 3 It is only an example of the control device 3 and does not constitute a limitation of the control device 3. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the control device may also include input and output devices, network access devices, buses, etc.

[0127] The processor 30 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0128] The memory 31 may be an internal storage unit of the control device 3, such as a hard disk or memory of the control device 3. The memory 31 may also be an external storage device of the control device 3, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the control device 3. Further, the memory 31 may also include both an internal storage unit and an external storage device of the control device 3. The memory 31 is used to store the computer program and other programs and data required by the control device. The memory 31 may also be used to temporarily store data that has been output or is to be output.

[0129] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0130] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0131] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0132] In the embodiments provided by the present invention, it should be understood that the disclosed devices / control devices and methods can be implemented in other ways. For example, the device / control device embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0133] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0134] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0135] If the integrated module / unit is implemented in the form of 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 present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned battery SOC value estimation method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practices in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practices, computer-readable media does not include electrical carrier signals and telecommunication signals.

[0136] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A method for estimating a battery SOC value, characterized in that: include: Determining a first target profile from a plurality of preset profiles based on a current charge rate of the battery, wherein for each profile in the plurality of profiles, each profile corresponds to a constant rate, each profile is used to represent a mapping relationship between a battery voltage value and a SOC value, each profile is obtained by correcting an initial profile corresponding to each profile based on historical operating data of the battery, each initial profile is obtained by charging and discharging at the constant rate corresponding to the corresponding profile, and, for all profiles in the plurality of profiles, the absolute value of the difference between the constant rate corresponding to the first target profile and the current charge rate of the battery is minimized; Determining the SOC value corresponding to the current voltage value of the battery as the target SOC value based on the mapping relationship between the battery voltage value and the SOC value in the first target spectrum; For each spectrum graph, the process of correcting the initial spectrum graph corresponding to each spectrum graph using the historical operation data of the battery includes: Obtaining the accumulated charging ampere-hours of the battery after a complete charging process, and using the accumulated charging ampere-hours as the terminal charging ampere-hours, wherein the complete charging process is used to indicate that the battery is charged until the accumulated charging ampere-hours no longer change with the extension of the charging time; Calculating the cumulative charging ampere-hours corresponding to each SOC value based on the charging terminal ampere-hours and the rated ampere-hours of the battery; For each SOC value, the accumulated charging ampere-hour is determined, and the time when the battery is charged to the accumulated charging ampere-hour is determined, and the charge / discharge rate and voltage value of the battery at the time are obtained. determining a second target spectrum map from the plurality of spectrum maps according to the charge and discharge rate of the battery at the moment, wherein, for all spectrum maps in the plurality of spectrum maps, the absolute value of the difference between the constant rate corresponding to the second target spectrum map and the charge and discharge rate at the moment is the smallest; Correcting the voltage value corresponding to each SOC value in the initial map corresponding to the second target map according to each SOC value and the voltage value at the moment corresponding to each SOC value; Calculating the cumulative charging ampere-hour corresponding to each SOC value based on the charging terminal ampere-hour and the rated ampere-hour of the battery includes: The accumulated charging ampere-hours corresponding to each SOC value are calculated according to the preset formula: SOC n％ =Ah 末端 -(1st)Oh 额定 Where, 0≤n≤100, SOC n％ Used to indicate the accumulated charging ampere-hours corresponding to SOC n%, Ah 末端 Ah is the terminal ampere-hour of charging 额定 is the rated ampere-hour of the battery.

2. The method according to claim 1, characterized in that The one complete charging process is a complete charging process among the m complete charging processes closest to the current moment before the current moment, where m is a positive integer greater than or equal to 2. For an SOC value in the second target map, if a voltage value corresponding to the SOC value is obtained in each charging process among the n complete charging processes, wherein the m complete charging processes include the n complete charging processes, the method further includes: The n voltage values ​​corresponding to the SOC value are averaged to obtain the voltage value corresponding to the SOC value in the second target map.

3. A battery SOC value estimation device, characterized in that: include: Target spectrum determination module and SOC value determination module; The target map determination module is configured to determine a first target map from a plurality of preset map maps based on a current charge rate of the battery, wherein for each map in the plurality of map maps, each map map corresponds to a constant rate, each map map is used to represent a mapping relationship between a battery voltage value and a SOC value, each map map is obtained by correcting an initial map corresponding to each map map based on historical operating data of the battery, each initial map map is obtained by charging and discharging at a constant rate corresponding to the corresponding map map, and for all map maps in the plurality of map maps, the absolute value of the difference between the constant rate corresponding to the first target map and the current charge rate of the battery is the smallest; The SOC value determination module is configured to determine the SOC value corresponding to the current voltage value of the battery as the target SOC value based on the mapping relationship between the battery voltage value and the SOC value in the first target spectrum. The target spectrum determination module is used for: Obtaining the accumulated charging ampere-hours of the battery after a complete charging process, and using the accumulated charging ampere-hours as the terminal charging ampere-hours, wherein the complete charging process is used to indicate that the battery is charged until the accumulated charging ampere-hours no longer change with the extension of the charging time; Calculating the cumulative charging ampere-hours corresponding to each SOC value based on the charging terminal ampere-hours and the rated ampere-hours of the battery; For each SOC value, the accumulated charging ampere-hour is determined, and the time when the battery is charged to the accumulated charging ampere-hour is determined, and the charge / discharge rate and voltage value of the battery at the time are obtained. determining a second target spectrum map from the plurality of spectrum maps according to the charge and discharge rate of the battery at the moment, wherein, for all spectrum maps in the plurality of spectrum maps, the absolute value of the difference between the constant rate corresponding to the second target spectrum map and the charge and discharge rate at the moment is the smallest; Correcting the voltage value corresponding to each SOC value in the initial map corresponding to the second target map according to each SOC value and the voltage value at the moment corresponding to each SOC value; The target spectrum determination module is used for: The accumulated charging ampere-hours corresponding to each SOC value are calculated according to the preset formula: SOC n％ =Ah 末端 -(1st)Oh 额定 Where, 0≤n≤100, SOC n％ Used to indicate the accumulated charging ampere-hours corresponding to SOC n%, Ah 末端 Ah is the terminal ampere-hour of charging 额定 is the rated ampere-hour of the battery.

4. The device according to claim 3, characterized in that The one complete charging process is a complete charging process among the m complete charging processes closest to the current moment before the current moment, where m is a positive integer greater than or equal to 2. For an SOC value in the second target map, if a voltage value corresponding to the SOC value is obtained in each charging process of the n complete charging processes, wherein the m complete charging processes include the n complete charging processes, the target map determining module is further configured to: The n voltage values ​​corresponding to the SOC value are averaged to obtain the voltage value corresponding to the SOC value in the second target map.

5. A vehicle comprising a control device, the control device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 2 are implemented.

6. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 2 are implemented.

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