Battery capacity determination method and battery health state determination method

Abstract

The invention relates to the field of new energy, in particular to a battery capacity determination method, a battery health state determination method, a computer program product, a processor, a distribution box, a BMS (Battery Management System) and electric energy equipment. Updating the high-voltage inflection point capacity of the battery according to the initial residual capacity corresponding to the initial static voltage and the first capacity charged when the battery is charged from the initial static voltage to the high-voltage inflection point to obtain the current high-voltage inflection point capacity of the battery; and determining the current maximum capacity of the battery according to the current high-voltage inflection point capacity. The accuracy of the battery health state can be improved.

Description

Technical Field

[0001] The present invention relates to the field of new energy, and in particular to a battery capacity determination method, a battery health status determination method, a computer program product, a processor, a distribution box, a BMS system and electric energy equipment. Background Art

[0002] With the rapid development of the automobile industry, new energy vehicles have gradually come into people's view. Compared with traditional cars, new energy vehicles emit less harmful substances, especially electric vehicles. The power source of electric vehicles is batteries, which can convert chemical energy into electrical energy to drive the motor to drive the car. Among them, the state of health (SOH) of the battery is an important parameter to measure the safety, reliability and power of electric vehicles.

[0003] In the related art, it is usually necessary to calculate the battery capacity by determining the high voltage inflection point of the battery charging curve in the offline data. However, when there are initial differences in the battery cells or the battery cells are aged, the high voltage inflection point of the battery charging curve may change. Therefore, there will be a large error in calculating the battery capacity using the offline data of the battery. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, one object of the present invention is to provide a method for determining battery capacity, which has the advantage of improving the accuracy of battery capacity.

[0005] According to a first aspect of an embodiment of the present invention, there is provided a method for determining battery capacity, comprising:

[0006] When the initial static voltage at which the battery starts to be charged is less than or equal to a preset voltage threshold, the high voltage inflection point capacity of the battery is updated according to the initial remaining capacity corresponding to the initial static voltage and the first capacity charged when the battery is charged from the initial static voltage to the high voltage inflection point, to obtain the current high voltage inflection point capacity of the battery;

[0007] The current maximum capacity of the battery is determined according to the current high-voltage inflection point capacity.

[0008] In an exemplary embodiment of the present disclosure, updating the high voltage inflection point capacity of the battery according to the initial remaining capacity corresponding to the initial static voltage and the first capacity charged when the battery is charged from the initial static voltage to the high voltage inflection point includes:

[0009] Obtaining the initial remaining capacity;

[0010] Obtaining the previous maximum capacity of the battery;

[0011] The current high voltage inflection point capacity is determined according to the previous maximum capacity, the initial remaining capacity and the first capacity.

[0012] In an exemplary embodiment of the present disclosure, determining the current high voltage inflection point capacity according to the previous maximum capacity, the initial remaining capacity and the first capacity includes:

[0013] Calculating the product of the previous maximum capacity and the initial remaining capacity;

[0014] Calculating a first sum of the product and the first capacity;

[0015] The first sum is used as the current high voltage inflection point capacity.

[0016] In an exemplary embodiment of the present disclosure, determining the current maximum capacity of the battery according to the current high voltage inflection point capacity includes:

[0017] Obtaining a second capacity charged into the battery when the battery is charged from a high voltage inflection point to full charge;

[0018] The current maximum capacity is determined according to the second capacity and the current high voltage inflection point capacity.

[0019] In an exemplary embodiment of the present disclosure, the method further includes:

[0020] When the initial static voltage is greater than the preset voltage threshold, the current maximum capacity is determined according to the last high voltage inflection point capacity of the battery.

[0021] In an exemplary embodiment of the present disclosure, before the high voltage inflection point capacity of the battery is updated according to the initial remaining capacity corresponding to the initial static voltage and the first capacity charged when the battery is charged from the initial static voltage to the high voltage inflection point, and the current high voltage inflection point capacity of the battery is obtained, the method further includes:

[0022] Obtaining a voltage-capacity curve of the battery during the charging process;

[0023] Performing smoothing filtering on the voltage-capacity curve to obtain a filtered voltage-capacity curve;

[0024] Performing a differential operation on the voltage-capacity curve to obtain a voltage-differential-capacity curve;

[0025] A peak value of the voltage differential capacity curve is obtained, and the high voltage inflection point is determined according to the peak value.

[0026] In an exemplary embodiment of the present disclosure, determining the high voltage inflection point according to the peak value includes:

[0027] acquiring a peak voltage corresponding to the peak value from the voltage-capacity curve;

[0028] Obtaining a maximum value of the peak voltage;

[0029] The maximum value is taken as the high voltage inflection point.

[0030] According to a second aspect of the present disclosure, a method for determining a battery health state is provided, which is applied to the capacity updating method described in any one of the first aspects, including:

[0031] Determine the current maximum capacity of the battery by the capacity updating method according to any one of the first aspects;

[0032] The health state of the battery is determined according to a ratio of the current maximum capacity to an initial capacity of the battery.

[0033] According to a third aspect of the present disclosure, a computer program product comprising instructions is provided. When the computer program product is run on the computer, the computer executes the battery capacity determination method as described in any one of the first aspects, or the battery health status determination method as described in the second aspect.

[0034] According to a fourth aspect of the present disclosure, a processor is provided, wherein the processor is configured to execute instructions to implement the battery capacity determination method as described in any one of the first aspect, or the battery health status determination method as described in the second aspect.

[0035] According to a fifth aspect of the present disclosure, there is provided a distribution box, comprising the processor as described in the third aspect.

[0036] According to a sixth aspect of the present disclosure, a BMS system is provided, comprising the distribution box as described in the fifth aspect, and / or comprising the processor as described in the fifth aspect.

[0037] According to a seventh aspect of the present disclosure, an electric energy device includes the BMS system as described in the sixth aspect.

[0038] The battery capacity determination method of the embodiment of the present invention, when the initial static voltage at the beginning of charging of the battery is less than or equal to a preset voltage threshold, updates the high voltage inflection point capacity of the battery according to the initial remaining capacity corresponding to the initial static voltage and the first capacity charged into the battery when it is charged from the initial static voltage to the high voltage inflection point, so as to obtain the current high voltage inflection point capacity of the battery; determines the current maximum capacity of the battery according to the current high voltage inflection point capacity, thereby avoiding the problem of large errors in calculating the battery capacity using offline data of the battery, thereby greatly improving the accuracy of the battery capacity.

[0039] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a flow chart of a method for determining battery capacity according to an exemplary embodiment;

[0041] Figure 2 is a schematic diagram of a voltage-capacity curve provided according to an exemplary embodiment;

[0042] Figure 3 is a schematic diagram of a voltage differential capacity curve provided according to an exemplary embodiment;

[0043] Figure 4 is a flow chart of a method for determining a battery health status according to an exemplary embodiment;

[0044] Figure 5 is a schematic diagram of a computer program product provided according to an exemplary embodiment;

[0045] Figure 6 is a block diagram of an electric energy device provided according to an exemplary embodiment. DETAILED DESCRIPTION

[0046] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0047] The following describes a method for determining battery capacity according to an embodiment of the present invention with reference to the accompanying drawings. Figure 1 As shown, the above-mentioned battery capacity determination method may include the following steps:

[0048] S1. When the initial static voltage at which the battery starts to be charged is less than or equal to a preset voltage threshold, the high voltage inflection point capacity of the battery is updated according to the initial remaining capacity corresponding to the initial static voltage and the first capacity charged when the battery is charged from the initial static voltage to the high voltage inflection point, to obtain the current high voltage inflection point capacity of the battery;

[0049] S2. Determine the current maximum capacity of the battery according to the current high voltage inflection point capacity.

[0050] In summary, the battery capacity determination method of the embodiment of the present invention, when the initial static voltage at which the battery starts charging is less than or equal to a preset voltage threshold, updates the high voltage inflection point capacity of the battery according to the initial remaining capacity corresponding to the initial static voltage and the first capacity charged when the battery is charged from the initial static voltage to the high voltage inflection point, to obtain the current high voltage inflection point capacity of the battery; determines the current maximum capacity of the battery according to the current high voltage inflection point capacity, thereby avoiding the problem of large errors in calculating the battery capacity using offline data of the battery, thereby greatly improving the accuracy of the battery capacity.

[0051] Below, each step of the method for determining battery capacity in this example implementation will be described in more detail with reference to the accompanying drawings and embodiments.

[0052] In step S1, when the initial static voltage at which the battery starts charging is less than or equal to a preset voltage threshold, the high voltage inflection point capacity of the battery is updated according to the initial remaining capacity corresponding to the initial static voltage and the first capacity charged when the battery is charged from the initial static voltage to the high voltage inflection point, so as to obtain the current high voltage inflection point capacity of the battery.

[0053] The following describes how to determine the first capacity charged into the battery when the battery is charged from the initial static voltage to the high voltage inflection point.

[0054] In an exemplary embodiment of the present disclosure, the battery may be a lithium ion battery. The embodiment of the present disclosure is described below by taking a lithium iron phosphate lithium ion battery as an example.

[0055] In an exemplary embodiment of the present invention, after the lithium iron phosphate lithium ion battery is discharged, the lithium iron phosphate lithium ion battery can be left to stand for a period of time, for example, the lithium iron phosphate lithium ion battery can be left to stand for two hours, and then the lithium iron phosphate lithium ion battery can be charged and the initial static voltage of the lithium iron phosphate lithium ion battery can be obtained.

[0056] In an exemplary embodiment of the present invention, if the measured static voltage of the lithium iron phosphate lithium-ion battery is smaller, the capacity of the lithium iron phosphate lithium-ion battery calculated based on the voltage at this time is closer to the actual capacity, that is, the capacity of the lithium iron phosphate lithium-ion battery is more accurate. Therefore, it is more accurate to obtain the first capacity charged into the lithium iron phosphate lithium-ion battery when it is charged from the current voltage to the high voltage inflection point, and then update the current high voltage inflection point capacity of the battery based on the first capacity. It is also more accurate, thereby obtaining more accurate data. In an exemplary embodiment of the present invention, the charging time and charging current of the lithium iron phosphate lithium-ion battery when it is charged from the current voltage to the high voltage inflection point can be obtained, and then the ampere-hour integration is used to calculate the first capacity charged into the lithium iron phosphate lithium-ion battery when it is charged from the current voltage to the high voltage inflection point. The ampere-hour integration method is a basic method for battery power metering. It uses the current-time accumulation method to perform real-time battery charge state estimation on dynamic lithium batteries. The calculation formula of the ampere-hour integration method is as follows:

[0057]

[0058] Among them, SOC0 is the initial charge value of the battery state of charge; CE is the rated capacity of the battery; I(t) is the charge and discharge current of the battery at time t; t is the charge and discharge time. The ampere-hour integration method is relatively less restricted by the battery's own conditions. The calculation method is simple and reliable, and it can estimate the battery's state of charge in real time.

[0059] The following describes how to determine the high voltage inflection point of lithium iron phosphate lithium-ion batteries.

[0060] Based on the above content, in an exemplary embodiment of the present invention, before the high voltage inflection point capacity of the battery is updated according to the initial remaining capacity corresponding to the initial static voltage and the first capacity charged when the battery is charged from the initial static voltage to the high voltage inflection point, and the current high voltage inflection point capacity of the battery is obtained, the method further includes:

[0061] S31, obtaining a voltage capacity curve of the battery during the charging process;

[0062] S32, performing smoothing filtering on the voltage-capacity curve to obtain a filtered voltage-capacity curve;

[0063] S33, performing a differential operation on the filtered voltage-capacity curve to obtain a voltage-differential capacity curve;

[0064] Generally speaking, the voltage capacity curve of lithium-ion batteries during the charge and discharge process has a relatively slow voltage change interval, which is called the voltage platform area. In the transition process between two different platform areas, there is a point where the voltage changes fastest, which is called the inflection point. For lithium iron phosphate batteries, there are three such voltage platform areas, so there are two inflection points, which are distinguished by voltage. The inflection point with higher voltage is marked as the high voltage inflection point (HVTP), and the inflection point with lower voltage is marked as the low voltage inflection point (LVTP).

[0065] In an exemplary embodiment of the present invention, the lithium iron phosphate lithium ion battery can be discharged to a cut-off voltage (SOC=0%) before the lithium iron phosphate lithium ion battery leaves the factory, and then the lithium iron phosphate lithium ion battery is charged, and the voltage-capacity curve of the lithium iron phosphate lithium ion battery during the charging process is recorded. The recorded voltage-capacity curve is, for example, Figure 2 As shown. Further, the voltage-capacity curve is smoothed and filtered to obtain a filtered voltage-capacity curve. Then, the voltage-capacity difference of the filtered voltage-capacity curve is calculated to obtain, for example Figure 3 The voltage differential capacity curve is shown.

[0066] S34. Obtain a peak value of the voltage differential capacity curve, and determine the high voltage inflection point according to the peak value.

[0067] In an exemplary embodiment of the present invention, a peak voltage corresponding to the peak value is obtained from the voltage-capacity curve; a maximum value of the peak voltage is obtained; and the maximum value is used as the high-voltage inflection point.

[0068] For example Figure 3 As shown, there are two peaks obtained from the voltage differential capacity curve, namely point A on the left and point B on the right. The peak voltage corresponding to point B on the right in the voltage capacity curve is greater than the peak voltage corresponding to point a on the left in the voltage capacity curve. The peak voltage at point B is the high voltage inflection point (HVTP) of the battery, and the peak voltage at point A is the low voltage inflection point (LVTP) of the battery.

[0069] Based on the above content, in an exemplary embodiment of the present invention, before updating the high voltage inflection point capacity of the battery according to the initial remaining capacity corresponding to the initial static voltage and the first capacity charged when the battery is charged from the initial static voltage to the high voltage inflection point, the method further includes:

[0070] S41. Obtain the initial remaining capacity.

[0071] In an exemplary embodiment of the present disclosure, a triggering static voltage correction (Relaxation Voltage Correction, RVC) can be used to obtain the initial residual capacity. Specifically, after obtaining the initial static voltage of the lithium iron phosphate lithium-ion battery, the initial residual capacity SOC corresponding to the initial static voltage is obtained by using the battery voltage and state of charge (State of Charge, SOC) corresponding diagram to look up the table. low .

[0072] In another exemplary embodiment of the present disclosure, the initial remaining capacity SOC can also be obtained by using the Kalman filter method. low The Kalman filter method is a method of predicting the state of charge of the battery pack in real time under dynamic conditions by first building a circuit model of resistors and capacitors, and then inputting the real-time voltage value of the circuit model. Therefore, by inputting the initial static voltage into the circuit model, the initial remaining capacity SOC low Since the accuracy is higher when the voltage changes more obviously during the discharge process, the Kalman filter method can also accurately predict the SOC state when the voltage is below the low voltage inflection point. The Kalman filter method can then accurately obtain the initial remaining capacity SOC corresponding to the initial static voltage. low , so as to obtain the high voltage inflection point capacity more accurately.

[0073] S42: Obtain the previous maximum capacity of the battery.

[0074] In an exemplary embodiment of the present disclosure, the last maximum capacity Q of the acid iron lithium ion battery after the last update of the high voltage inflection point capacity is obtained. last .

[0075] S43: Determine the current high voltage inflection point capacity according to the previous maximum capacity, the initial remaining capacity and the first capacity.

[0076] Based on the above content, in an exemplary embodiment of the present disclosure, determining the current high voltage inflection point capacity according to the previous maximum capacity, the initial remaining capacity and the first capacity includes:

[0077] S431, calculating the product of the previous maximum capacity and the initial remaining capacity;

[0078] S432, calculating a first sum of the product and the first capacity;

[0079] S433: Use the first sum as the current high voltage inflection point capacity.

[0080] In an exemplary embodiment of the present disclosure, the current high voltage inflection point capacity may be calculated using the following formula:

[0081] Q HVTP =Qsoc+SOC low *Q last (2);

[0082] Among them, Q HVTP It indicates the current high voltage inflection point capacity, and Qsoc indicates the first capacity.

[0083] In step S2, the current maximum capacity of the battery is determined according to the current high voltage inflection point capacity.

[0084] Based on the above content, in an exemplary embodiment of the present disclosure, determining the current maximum capacity of the battery according to the current high voltage inflection point capacity includes:

[0085] S21, obtaining a second capacity charged into the battery when the battery is charged from a high voltage inflection point to a full charge;

[0086] S22. Determine the current maximum capacity according to the second capacity and the current high voltage inflection point capacity.

[0087] In an exemplary embodiment of the present disclosure, the current maximum capacity of the lithium iron ion battery can be calculated using the following formula:

[0088] Q max =Q HVTP +Q HVP (3);

[0089] Among them, Q max Indicates the current maximum capacity, Q HVP Indicates the second capacity.

[0090] Based on the above content, in an exemplary embodiment of the present disclosure, the method further includes:

[0091] S5. When the initial static voltage is greater than the preset voltage threshold, determining the current maximum capacity according to the last high voltage inflection point capacity of the battery.

[0092] In an exemplary embodiment of the present disclosure, when the current static voltage is greater than the preset voltage threshold, the last updated high voltage inflection point capacity Q is used. HVTP Substitute into formula (3) to calculate the current maximum capacity of the battery.

[0093] In summary, the battery capacity determination method disclosed in the present invention can update the high voltage inflection point capacity of the battery, and determine the current maximum capacity of the battery according to the current high voltage inflection point capacity, thereby avoiding the problem of large errors in calculating the battery capacity using offline data of the battery, thereby greatly improving the accuracy of the battery capacity.

[0094] Reference below Figure 4 The method for determining the battery health status according to an embodiment of the present invention is described. Figure 4 As shown, the above-mentioned method for determining the battery health status may include the following steps:

[0095] S61, determining the current maximum capacity of the battery by the above capacity updating method;

[0096] S62: Determine a health state of the battery according to a ratio of the current maximum capacity to the initial capacity of the battery.

[0097] In an exemplary embodiment of the present disclosure, after the current maximum capacity of the battery is determined by the above-mentioned battery capacity determination method, the ratio of the current maximum capacity to the initial capacity of the battery is calculated, and the battery health status is determined according to the ratio.

[0098] In an exemplary embodiment of the present disclosure, the ratio may be converted into a ratio, and then the ratio is used as a battery health status parameter. In an exemplary embodiment of the present disclosure, when the ratio of the current maximum capacity to the initial capacity of the battery is less than or equal to a preset threshold, a prompt message is sent to prompt the user to replace or repair the battery.

[0099] To sum up, the battery health status determination method provided by the present invention can update the high voltage inflection point capacity of the battery, determine the current maximum capacity of the battery according to the updated high voltage inflection point capacity, and then determine the battery health status according to the current maximum capacity of the battery, which can greatly improve the accuracy of the health status.

[0100] After introducing the battery capacity determination method and the battery health state determination method according to the exemplary embodiment of the present invention, next, reference is made to Figure 5 A computer program product according to an exemplary embodiment of the present invention is described. The computer program product may be a computer program product comprising instructions, which, when executed on a computer, causes the computer to execute the battery capacity determination method or the battery health status determination method as described above. Figure 5 As shown, a program product 500 for implementing the above method according to an embodiment of the present invention is described, which can adopt a portable compact disk read-only memory (CD-ROM) and include program code, and can be run on a device, such as a personal computer. However, the program product of the present invention is not limited thereto. In this document, a readable storage medium can be any tangible medium containing or storing a program, which can be used by or in combination with an instruction execution system, an apparatus or a device.

[0101] The program product may use any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0102] Computer readable signal media may include data signals propagated in baseband or as part of a carrier wave, in which readable program code is carried. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Readable signal media may also be any readable medium other than a readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0103] The program code included in the readable medium can be transmitted with any appropriate medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination of the above. The program code for performing the operation of the present invention can be written in any combination of one or more programming languages, and the programming language includes object-oriented programming languages-such as Java, C++, etc., and also includes conventional procedural programming languages-such as "C" language or similar programming languages. The program code can be executed completely on the user computing device, partially on the user computing device, partially on the remote computing device, or completely on the remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (for example, using an Internet service provider to connect through the Internet).

[0104] After introducing the computer program product of the exemplary embodiment of the present invention, the processor of the exemplary embodiment of the present invention is described below. The processor can be configured to execute instructions to implement the battery capacity determination method as described above, or the battery health status determination method as described above. In an exemplary embodiment of the present disclosure, the processor can be a chip, an MCU, an integrated circuit, or a terminal device, etc.

[0105] After introducing the processor according to the exemplary embodiment of the present invention, the distribution box according to the exemplary embodiment of the present invention is described below. The distribution box includes the processor as described above, and the processor is arranged in the distribution box.

[0106] After introducing the distribution box of the exemplary embodiment of the present invention, the battery management system (BMS) system of the exemplary embodiment of the present invention is described next. The BMS system includes the distribution box as described above, and / or the processor as described above, and the distribution box and / or the processor are arranged in the BMS system.

[0107] After introducing the BMS system of the exemplary embodiment of the present invention, next, refer to Figure 6 The electric energy device according to the exemplary embodiment of the present invention is described. The electric energy device includes the BMS system as described above, and the BMS system is arranged in the electric energy device. The electric energy device can be a new energy vehicle, an aircraft, a ship, an energy storage cabinet, etc.

[0108] Figure 6 The electric energy device 60 shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present invention.

[0109] like Figure 6 As shown, the electric energy device 60 is in the form of a general-purpose computing device. The components of the electric energy device 60 may include, but are not limited to: at least one processing unit 610, at least one storage unit 620, a bus 630 connecting different system components (including the storage unit 620 and the processing unit 610), and a display unit 640. The storage unit stores program code, which can be executed by the processing unit 610, so that the processing unit 610 performs the steps according to various exemplary embodiments of the present invention described in the above "Exemplary Method" section of this specification. For example, the processing unit 610 may perform the following steps: Figure 1 Steps S1 and S2 shown in , or Figure 4 Step S61 and step S62 shown in FIG.

[0110] The storage unit 620 may include a volatile storage unit, such as a random access storage unit (RAM) 6201 and / or a cache storage unit 6202, and may further include a read-only storage unit (ROM) 6203. The storage unit 620 may also include a program / utility 6204 having a set (at least one) of program modules 6205, such program modules 6205 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination thereof may include the implementation of a network environment.

[0111] The bus 630 may include a data bus, an address bus, and a control bus.

[0112] The power device 60 can also communicate with one or more external devices 70 (e.g., keyboards, pointing devices, Bluetooth devices, etc.), and this communication can be performed through an input / output (I / O) interface 650. The power device 60 also includes a display unit 640, which is connected to the input / output (I / O) interface 650 for display. In addition, the power device 60 can also communicate with one or more networks (e.g., local area networks (LANs), wide area networks (WANs) and / or public networks, such as the Internet) through a network adapter 660. As shown in the figure, the network adapter 660 communicates with other modules of the electronic device 60 through a bus 630. It should be understood that, although not shown in the figure, other hardware and / or software modules can be used in conjunction with the power device 60, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0113] In addition, although the operations of the method of the present invention are described in a specific order in the drawings, this does not require or imply that the operations must be performed in this specific order, or that all the operations shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps.

[0114] Although the spirit and principle of the present invention have been described with reference to several specific embodiments, it should be understood that the present invention is not limited to the disclosed specific embodiments, and the division of various aspects does not mean that the features in these aspects cannot be combined to benefit, and such division is only for the convenience of expression. The present invention is intended to cover various modifications and equivalent arrangements included in the spirit and scope of the attached claims.

Claims

1. A method for determining battery capacity, characterized in that: include: When the initial static voltage at which the battery starts to be charged is less than or equal to a preset voltage threshold, the high voltage inflection point capacity of the battery is updated according to the initial remaining capacity corresponding to the initial static voltage and the first capacity charged when the battery is charged from the initial static voltage to the high voltage inflection point, to obtain the current high voltage inflection point capacity of the battery; The current maximum capacity of the battery is determined according to the current high voltage inflection point capacity.

2. The method according to claim 1, characterized in that The updating of the high voltage inflection point capacity of the battery according to the initial remaining capacity corresponding to the initial static voltage and the first capacity charged when the battery is charged from the initial static voltage to the high voltage inflection point comprises: Obtaining the initial remaining capacity; Obtaining the previous maximum capacity of the battery; The current high voltage inflection point capacity is determined according to the previous maximum capacity, the initial remaining capacity and the first capacity.

3. The method according to claim 2, characterized in that The determining the current high voltage inflection point capacity according to the previous maximum capacity, the initial remaining capacity and the first capacity comprises: Calculating the product of the previous maximum capacity and the initial remaining capacity; Calculating a first sum of the product and the first capacity; The first sum is used as the current high voltage inflection point capacity.

4. The method according to claim 1, characterized in that: Determining the current maximum capacity of the battery according to the current high voltage inflection point capacity includes: Obtaining a second capacity charged into the battery when the battery is charged from a high voltage inflection point to full charge; The current maximum capacity is determined according to the second capacity and the current high voltage inflection point capacity.

5. The method according to claim 1, characterized in that The method further comprises: When the initial static voltage is greater than the preset voltage threshold, the current maximum capacity is determined according to the last high voltage inflection point capacity of the battery.

6. The method according to claim 1, characterized in that Before updating the high voltage inflection point capacity of the battery according to the initial remaining capacity corresponding to the initial static voltage and the first capacity charged when the battery is charged from the initial static voltage to the high voltage inflection point to obtain the current high voltage inflection point capacity of the battery, the method further includes: Obtaining a voltage-capacity curve of the battery during the charging process; Performing smoothing filtering on the voltage-capacity curve to obtain a filtered voltage-capacity curve; Performing a differential operation on the voltage-capacity curve to obtain a voltage-differential-capacity curve; A peak value of the voltage differential capacity curve is obtained, and the high voltage inflection point is determined according to the peak value.

7. The method according to claim 6, characterized in that Determining the high voltage inflection point according to the peak value comprises: acquiring a peak voltage corresponding to the peak value from the voltage-capacity curve; Obtaining a maximum value of the peak voltage; The maximum value is taken as the high voltage inflection point.

8. A method for determining a battery health status, characterized in that: include: Determine the current maximum capacity of the battery by the capacity updating method according to any one of claims 1 to 7; The health state of the battery is determined according to a ratio of the current maximum capacity to an initial capacity of the battery.

9. A computer program product comprising instructions, characterized in that When the computer program product is run on a computer, the computer is enabled to execute the battery capacity determination method according to any one of claims 1 to 7, or the battery health state determination method according to claim 8.

10. A processor, characterized in that: The processor is configured to execute instructions to implement the battery capacity determination method according to any one of claims 1 to 7, or the battery health state determination method according to claim 8.

11. A distribution box, characterized in that: Comprising the processor of claim 10.

12. A BMS system, characterized in that: Includes the distribution box as claimed in claim 11, and / or includes the processor as claimed in claim 10.

13. An electric energy device, characterized in that: Comprising the BMS system as claimed in claim 12.

Images