Lithium ion battery SOC correction method and system

Abstract

The invention provides a lithium ion battery SOC correction method and system, and the method comprises the steps: obtaining the first electric quantity information of a lithium ion battery according to the characteristic that a UPS is in a high electric quantity state for a long time, obtaining the first voltage information of the lithium ion battery when the first electric quantity information exceeds a preset first electric quantity threshold value, and correcting the SOC of the lithium ion battery according to the first voltage information and the first electric quantity information. Judging whether to enter a lithium ion battery SOC correction mode or not; when entering a correction mode, judging whether the second voltage information is in a stable state according to the second voltage information, if so, switching the battery into an open circuit state according to a preset first time period, and calculating according to the third voltage information to obtain second electric quantity information for correcting the first electric quantity information; the electric quantity is calculated through the open-circuit voltage according to the characteristic that the UPS is in the high-electric-quantity state for a long time, so that the SOC of the lithium ion battery is corrected, and the correction efficiency of the SOC of the lithium ion battery is improved.

Description

Technical Field

[0001] The present invention relates to the field of lithium-ion batteries, and more specifically, to a lithium-ion battery SOC correction method and system. Background Art

[0002] SOC (State of Charge) is the charge state of a lithium-ion battery, which reflects the current remaining power level of the lithium-ion battery, also known as the remaining power. The SOC of a lithium-ion battery is closely related to its voltage level. When the SOC approaches 100%, the voltage of the lithium-ion battery will gradually rise until it reaches the fully charged state (Fully Charged). On the contrary, when the SOC approaches 0%, the voltage of the lithium-ion battery will gradually decrease until it reaches the discharge termination voltage (Cut-off Voltage). Therefore, it is very important to accurately monitor the SOC of lithium-ion batteries, which helps to avoid the negative effects of excessive charging and discharging on the service life of lithium-ion batteries.

[0003] UPS (Uninterruptible Power Supply) is a core IT device that plays a vital role in ensuring the power supply security required for the normal operation of the data center. When the power grid encounters various faults, the UPS outputs high-quality power through the configured battery through AC inversion to avoid data loss or task interruption caused by power outages. UPS is an emergency power supply, and the battery has phenomena such as power consumption detection and natural discharge, which need to be corrected to obtain the SOC of the lithium-ion battery. Therefore, a lithium-ion battery SOC correction technology that automatically corrects the SOC is urgently needed. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a lithium-ion battery SOC correction method and system. According to the characteristic that the UPS is in a high-power state for a long time, when the first power information of the lithium-ion battery exceeds a preset first power threshold, it is determined whether to enter the lithium-ion battery SOC correction mode according to the first voltage information and the first power information of the lithium-ion battery; when entering the correction mode, it is determined whether the second voltage information is in a stable state according to the second voltage information. If so, the battery is switched to an open-circuit state according to a preset first time period, and the second power information is calculated according to the third voltage information to correct the first power information. According to the characteristic that the UPS is in a high-power state for a long time, the present invention calculates the power by the open-circuit voltage to correct the lithium-ion battery SOC, thereby improving the correction efficiency of the lithium-ion battery SOC.

[0005] A first aspect of the present invention provides a lithium-ion battery SOC correction method, the method comprising: Acquire first power information; Determining whether the first power information exceeds a preset first power threshold; If yes, obtain first voltage information; determining whether to enter a correction mode according to the first power information and the first voltage information; If yes, obtaining second voltage information; determining, according to the second voltage information, whether the second voltage information is in a stable state; If so, switching the battery to an open circuit state according to a preset first time period; Acquiring third voltage information; Obtaining second power information according to the third voltage information; The first power information is corrected according to the second power information.

[0006] In this solution, judging whether to enter the correction mode according to the first power information and the first voltage information is specifically: According to the first voltage information, searching a set first power correspondence table to obtain third power information; Calculating a difference between the first power information and the third power information to obtain first power difference information; Determining whether the first power difference information exceeds a preset first power difference threshold; If so, enter correction mode; If not, the correction mode is not entered.

[0007] In this solution, judging whether the second voltage information is in a stable state according to the second voltage information is specifically: Obtaining a first voltage sequence according to the second voltage information; obtaining first quantity information; Obtain at least two fourth voltage information according to the first voltage sequence and the first quantity information; Obtaining first deviation information according to the fourth voltage information; Determining whether the first deviation information is lower than a preset deviation threshold; If not, it is determined that the second voltage information is in an unstable state; If so, a first peak-to-peak value is obtained according to the first voltage sequence; Determining whether the first peak-to-peak value exceeds a preset peak-to-peak value threshold; If yes, it is determined that the second voltage information is in a stable state; If not, it is determined that the second voltage information is in an unstable state.

[0008] In this solution, the second power information is obtained according to the first voltage information, specifically: Acquiring first temperature information; Determining a first open circuit voltage relationship according to the first temperature information; The second electric quantity information is obtained according to the first open circuit voltage relationship and the first voltage information.

[0009] In this solution, the first power information is corrected according to the second power information, specifically: Obtaining second power difference information according to a difference between the second power information and the first power information; Determining whether the second power difference information exceeds a preset second power difference threshold; If yes, setting the first power information according to the second power information; If not, the first power correspondence table is updated according to the second power information.

[0010] This plan also includes: According to the first time period, acquiring at least two second power information to obtain a first power sequence; Determining first power deviation information according to the first power sequence; Determining whether the first power deviation information is lower than a preset power deviation threshold; If yes, then calculating the mean of the first power sequence to correct the first power information; If not, clear the first power sequence.

[0011] A second aspect of the present invention provides a lithium-ion battery SOC correction system, characterized in that the system comprises: Processor, first voltage acquisition module, second voltage acquisition module, power recording module, voltage open circuit module; The processor is used to enter a correction mode according to first voltage information collected by a first voltage collection module, decide to perform a correction operation according to second voltage information collected by a second voltage collection module, adjust the connection state between the lithium-ion battery and the load through a voltage open circuit module, and update the first power information recorded by a power recording module.

[0012] In this solution, the voltage open circuit module is specifically: The state is switched between a load connection state and a load disconnection state according to a control signal of a processor.

[0013] In this solution, the first voltage acquisition module is specifically: When the voltage open circuit module is in a load connection state, the voltage information collected by the first voltage collection module is the first voltage information; When the voltage open circuit module is in a load disconnection state, the voltage information collected by the first voltage collection module is the third voltage information.

[0014] In this solution, the second voltage acquisition module further includes: A second voltage information acquisition and recording unit, used for acquiring and recording the second voltage information to obtain a first voltage sequence; A voltage integration unit, used for performing voltage integration according to the first voltage sequence to obtain a voltage integration value; The peak-to-peak value unit is used to obtain the voltage peak-to-peak value according to the first voltage sequence analysis.

[0015] The present invention provides a lithium-ion battery SOC correction method and system. According to the characteristic that a UPS is in a high-power state for a long time, first power information of the lithium-ion battery is obtained. When the first power information exceeds a preset first power threshold, first voltage information of the lithium-ion battery is obtained. According to the first voltage information and the first power information, it is judged whether to enter a lithium-ion battery SOC correction mode; when entering the correction mode, it is judged according to the second voltage information whether the second voltage information is in a stable state. If so, the battery is switched to an open-circuit state according to a preset first time period, and the second power information is calculated according to the third voltage information to correct the first power information. According to the characteristic that a UPS is in a high-power state for a long time, the present invention calculates the power by the open-circuit voltage to correct the lithium-ion battery SOC, thereby improving the correction efficiency of the lithium-ion battery SOC. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and should not be regarded as limiting the scope.

[0017] Figure 1 A flow chart of a lithium-ion battery SOC correction method according to the present invention is shown; Figure 2 A flowchart of entering a correction mode provided by an embodiment of the present invention is shown; Figure 3 A flow chart showing whether the second voltage information provided by an embodiment of the present invention is in a stable state is shown; Figure 4 A block diagram of a lithium-ion battery SOC correction system of the present invention is shown. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] Unless otherwise defined, all terms (including technical and scientific terms) used in the embodiments of the present invention have the same meanings as commonly understood by those skilled in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless the embodiments of the present invention are explicitly defined in this way.

[0020] The words "first", "second" and similar words used in the embodiments of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "one", "an" or "the" and similar words do not indicate a quantity limitation, but indicate the existence of at least one. Similarly, words such as "include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The steps before or after the method of the embodiment of the present invention are not necessarily carried out in order. On the contrary, various steps can be processed in reverse order or simultaneously. At the same time, other operations can also be added to these processes, or a step or several steps can be removed from these processes.

[0021] In addition, the functional modules in the various embodiments of the present invention may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0022] Figure 1 A flow chart of a lithium-ion battery SOC correction method of the present invention is shown.

[0023] like Figure 1 As shown, the first aspect of the present invention discloses a method for correcting SOC of a lithium-ion battery, the method comprising: S102, obtaining first power information; S104, determining whether the first power information exceeds a preset first power threshold; S106, if yes, obtain first voltage information; S108, determining whether to enter a correction mode according to the first power information and the first voltage information; S110, if yes, obtain second voltage information; S112, determining whether the second voltage information is in a stable state according to the second voltage information; S114, if yes, switching the battery to an open circuit state according to a preset first time period; S116, obtaining third voltage information; S118, obtaining second power information according to the third voltage information; S120: Modify the first power information according to the second power information.

[0024] It should be noted that the first power information is the power value recorded by the lithium-ion battery, that is, the SOC recorded value of the lithium-ion battery; the first voltage information is the voltage value at the positive and negative terminals of the lithium-ion battery; the second voltage information is the input power voltage of the UPS, usually the AC power; the open circuit state is the state where the lithium-ion battery is disconnected from the load; the third voltage information is the open circuit voltage value at the positive and negative terminals of the lithium-ion battery; the second power information is the power value of the lithium-ion battery obtained by reverse checking the open circuit voltage, that is, the SOC corrected value of the lithium-ion battery.

[0025] In this embodiment, since the UPS is in a high power state for a long time, this embodiment corrects the SOC when the lithium-ion battery is in a high power state. When the first power information exceeds the preset first power threshold, it means that the power of the lithium-ion battery reaches the preset correction power requirement. At this time, the first judgment is made according to the first voltage information of the lithium-ion battery; the corresponding power value is obtained by reverse checking according to the first voltage information. When the difference between the power value obtained by reverse checking and the first power information exceeds the set tolerance, it means that the SOC deviation of the lithium-ion battery is large, and the correction mode is required to correct the SOC of the lithium-ion battery. Since there is a short-term disconnection state between the lithium-ion battery and the load when the SOC is corrected, usually at the millisecond level, therefore, in order to ensure that the UPS can complete the power supply and the continuous power-off requirements of the load, this embodiment first detects the stability of the second voltage information, that is, detects the stability of the input power supply. When the second voltage information is in a stable state, the battery is switched to an open circuit state according to the preset first time period to correct the SOC of the lithium-ion battery. When the lithium-ion battery is in an open circuit state, the open circuit voltage of the lithium-ion battery is measured, that is, the third voltage information; then the second power information is calculated based on the relationship between the open circuit voltage and the power, that is, the OCV relationship; finally, when the deviation value between the first power information and the second power information exceeds the preset deviation tolerance, it means that the SOC of the lithium-ion battery needs to be corrected. At this time, the first power information is set according to the second power information to achieve the effect of correcting the SOC of the lithium-ion battery. According to the characteristic that the UPS is in a high power state for a long time, this embodiment calculates the power through the open circuit voltage to correct the SOC of the lithium-ion battery, thereby improving the correction efficiency of the SOC of the lithium-ion battery while ensuring that the load power supply is continuously supplied.

[0026] Figure 2 A flow chart of entering a correction mode provided by an embodiment of the present invention is shown.

[0027] According to an embodiment of the present invention, Figure 2 As shown, judging whether to enter the correction mode according to the first power information and the first voltage information is specifically as follows: S202, searching a set first power correspondence table according to the first voltage information to obtain third power information; S204, calculating a difference between the first power information and the third power information to obtain first power difference information; S206, determining whether the first power difference information exceeds a preset first power difference threshold; S208, if yes, enter correction mode; S210, if not, then do not enter the correction mode.

[0028] It should be noted that the first power correspondence table is a table of the correspondence between voltage and power when the lithium-ion battery is in a connected state with the load. In this embodiment, the first power correspondence table recorded by each lithium-ion battery is first searched according to the first voltage information to obtain the third power information, which is recorded as the lithium-ion SOC calculated value; wherein, the first power correspondence table is a correspondence table recorded and updated and saved by each lithium-ion battery itself. Then, the difference between the first power information and the third power information is calculated to obtain the first power difference information, which indicates the difference between the SOC recorded value and the SOC calculated value of the lithium-ion battery. Determine whether the first power difference information is the first power difference threshold; if so, it means that the SOC recorded value and the SOC calculated value differ greatly, and it is necessary to enter the correction mode to perform the correction operation; if not, it means that the SOC recorded value and the SOC calculated value differ little, and no correction is required.

[0029] Figure 3 A flow chart for determining whether the second voltage information provided by an embodiment of the present invention is in a stable state is shown.

[0030] According to an embodiment of the present invention, Figure 3 As shown, judging whether the second voltage information is in a stable state according to the second voltage information is specifically as follows: S302, obtaining a first voltage sequence according to the second voltage information; S304, obtaining first quantity information; S306, obtaining at least two fourth voltage information according to the first voltage sequence and the first quantity information; S308, obtaining first deviation information according to the fourth voltage information; S310, determining whether the first deviation information is lower than a preset deviation threshold; S312, if not, determining that the second voltage information is in an unstable state; S314, if yes, obtaining a first peak-to-peak value according to the first voltage sequence; S316, determining whether the first peak-to-peak value exceeds a preset peak-to-peak value threshold; S318, if yes, then determine that the second voltage information is in a stable state; S312: If not, it is determined that the second voltage information is in an unstable state.

[0031] It should be noted that the first voltage sequence is a sequence composed of second voltage information collected according to a preset period; the fourth voltage information is a voltage integral value obtained according to a preset voltage integral calculation method; the first quantity information is the voltage quantity used to calculate the voltage integral value; the first deviation information is the deviation value between all fourth voltage information. As an implementation method, the deviation value is the difference between the maximum value and the minimum value of the fourth voltage information. As another implementation method, the deviation value is the sum of the differences between the fourth voltage information and the mean value of the fourth voltage information; the first peak-to-peak value is the difference between the maximum value and the minimum value in the first voltage sequence within the same input power cycle.

[0032] In this embodiment, the stability of the input power supply of the UPS is judged to avoid performing SOC correction when the power supply is unstable, which may lead to the risk of load power outage. Usually in practical applications, the input power supply of the UPS is AC power, that is, 220 volts AC. According to the set time period, this embodiment continuously collects and records the voltage value of the input power supply to obtain a first voltage sequence. According to the preset voltage integral value calculation method, the voltage value in the first voltage sequence is extracted according to the set first quantity information, and the voltage integral value, that is, the fourth voltage information, is calculated. According to the several calculated voltage integral values, the deviation value between the voltage integral values ​​is calculated to obtain the first deviation information. It is judged whether the first deviation information is lower than the preset deviation threshold; if not, it means that the output deviation of the input power supply is large, that is, it is determined that the input power supply stability is poor; if so, it means that the output deviation of the input power supply is small. At this time, it is judged whether the input power supply meets the power supply voltage requirement by detecting the peak-to-peak value of the input power supply. Determine whether the first peak-to-peak value exceeds a preset peak-to-peak value threshold; if so, it indicates that the input power supply can meet the power supply voltage requirement, and the second voltage information is determined to be in a stable state; if not, it indicates that there is a risk of insufficient power supply voltage of the input power supply, and the second voltage information is determined to be in an unstable state.

[0033] According to an embodiment of the present invention, obtaining the second power information according to the third voltage information is specifically: Acquiring first temperature information; Determining a first open circuit voltage relationship according to the first temperature information; The second electric quantity information is obtained according to the first open circuit voltage relationship and the third voltage information.

[0034] It should be noted that, since the battery temperature affects the internal resistance of the battery, different temperatures will have an impact on the voltage-based power value. In this embodiment, the corresponding OCV relationship is selected according to the temperature value to calculate the power value according to the voltage value. The first temperature information is the temperature value of the lithium-ion battery. According to the first temperature information, the first open circuit voltage relationship corresponding to the temperature, that is, the OCV relationship, is searched and selected. Then, according to the third voltage information and the OCV relationship, the second power information is calculated as the SOC correction value.

[0035] According to an embodiment of the present invention, the modifying the first power information according to the second power information is specifically: Obtaining second power difference information according to a difference between the second power information and the first power information; Determining whether the second power difference information exceeds a preset second power difference threshold; If yes, setting the first power information according to the second power information; If not, the first power correspondence table is updated according to the second power information.

[0036] It should be noted that, in the present embodiment, the SOC recorded value is corrected or the first power correspondence table is updated according to the difference between the SOC correction value and the SOC recorded value. According to the difference between the second power information and the first power information, the second power difference information is obtained to indicate the deviation between the SOC correction value and the SOC recorded value. It is determined whether the second power difference information exceeds the preset second power difference threshold; if so, it indicates that the deviation between the SOC correction value and the SOC recorded value is large, and the SOC recorded value needs to be set according to the SOC correction value to achieve the effect of SOC correction of the lithium-ion battery; if not, it indicates that the deviation between the SOC correction value and the SOC recorded value is small, and the first power correspondence table is updated according to the second power information to reduce the probability of false triggering of the correction mode and improve the efficiency of SOC correction.

[0037] According to an embodiment of the present invention, it also includes: According to the first time period, acquiring at least two second power information to obtain a first power sequence; Determining first power deviation information according to the first power sequence; Determining whether the first power deviation information is lower than a preset power deviation threshold; If yes, then calculating the mean of the first power sequence to correct the first power information; If not, clear the first power sequence.

[0038] It should be noted that, in order to improve the accuracy of SOC correction, in this embodiment, according to the first time period, by obtaining at least two second power information, a first power sequence is obtained to calculate the first power deviation information. The first power deviation information represents the stability of the SOC correction value obtained by multiple measurements. It is judged whether the first power deviation information is lower than the preset power deviation threshold; if so, it means that the SOC correction value is in a stable state and can be used to correct the current SOC record value; if not, it means that there is an abnormality in the measurement and calculation of the SOC correction value, then the first power sequence is cleared, and the SOC correction value is re-measured.

[0039] It is worth mentioning that it also includes: Obtain charging and discharging record information; According to the charge and discharge record information, obtaining second number information; Determining first revised weight information according to the second number of times information; The second power information is corrected according to the first correction weight information.

[0040] It should be noted that the second number of times information is the number of cycles of charge and discharge of the lithium-ion battery. In this embodiment, the number of cycles of charge and discharge of the lithium-ion battery is used to indicate the aging degree of the lithium-ion battery; and according to the aging degree of the lithium-ion battery, the second power information is corrected, that is, the SOC correction value is adjusted. First, according to the second number of times information, the first correction weight information is determined by looking up the table. Then, according to the first correction weight information, the second power information is corrected.

[0041] It is worth mentioning that it also includes: Obtain charging and discharging record information; Sending the charge and discharge record information to a neural network model to obtain a second open circuit voltage relationship; The first open circuit voltage relationship equation is set according to the second open circuit voltage relationship equation.

[0042] It should be noted that the charging record includes but is not limited to the charge and discharge starting power, charge and discharge cut-off power or charge and discharge time, etc. The charging record is sent to the neural network model, and the neural network model outputs an OCV correction relationship that conforms to the actual working conditions of the lithium-ion battery according to the use of the lithium-ion battery, that is, the second open-circuit voltage relationship, which is used to set the first open-circuit voltage relationship.

[0043] It is worth mentioning that it also includes: Determine when the UPS is in charging state; Acquiring first voltage information and first current information; Determining whether the first voltage information reaches a preset first voltage threshold; If yes, determining whether the first current information exceeds a preset first current threshold; If not, determining whether the first power information is a preset power upper limit value; If not, enter the correction mode.

[0044] It should be noted that the present embodiment sets a rule for triggering the correction mode when fully charged, that is, when the lithium-ion battery switches to a fully charged state during charging, the correction mode is automatically entered according to the power value. The first current information is the charging current of the lithium-ion battery. When the voltage value at both ends of the positive and negative electrodes of the lithium-ion battery, that is, the first voltage information, exceeds the preset first voltage threshold, it indicates that the voltage value of the lithium-ion battery has reached the fully charged voltage state; at this time, it is determined whether the first current information exceeds the preset first current threshold. If not, it indicates that the charging current of the lithium-ion battery has not exceeded the set minimum charging current; the lithium-ion battery is already in a fully charged voltage state, and the charging current does not exceed the minimum charging current, then it can be determined that the lithium-ion battery is in a fully charged state. At this time, if the power value of the lithium-ion battery does not exceed the preset upper limit of the charging power, it automatically enters the correction mode to trigger the SOC correction operation of the lithium-ion battery.

[0045] Figure 4 A block diagram of a lithium-ion battery SOC correction system of the present invention is shown.

[0046] like Figure 4 As shown, the second aspect of the present invention discloses a lithium-ion battery SOC correction system, the system comprising: Processor 401, first voltage acquisition module 402, second voltage acquisition module 403, power recording module 404, voltage open circuit module 405; The processor is used to enter a correction mode according to first voltage information collected by a first voltage collection module, decide to perform a correction operation according to second voltage information collected by a second voltage collection module, adjust the connection state between the lithium-ion battery and the load through a voltage open circuit module, and update the first power information recorded by a power recording module.

[0047] It should be noted that the processor serves as the data processing center and control center of the lithium-ion battery, and is used to calculate the second power information based on the first voltage information collected by the first voltage acquisition module to determine whether to enter the correction mode; it is also used to perform a correction operation when it is determined that the second voltage information is in a stable state based on the second voltage information collected by the second voltage acquisition module; it is also used to control the voltage open circuit module to adjust the connection state between the battery and the load; it is also used to output the first power information according to the power recording module or adjust the first power information recorded by the power recording module.

[0048] According to an embodiment of the present invention, the voltage open circuit module is specifically: The state is switched between a load connection state and a load disconnection state according to a control signal of a processor.

[0049] It should be noted that, in this embodiment, the voltage open circuit module is a channel device such as an analog switch or a relay, which can switch the connection state of the channel device according to the control signal of the processor. The connection state includes a load connection state when the lithium-ion battery is connected to the load, and a load disconnection state when the lithium-ion battery is disconnected from the load.

[0050] According to an embodiment of the present invention, the first voltage acquisition module is specifically: When the voltage open circuit module is in a load connection state, the voltage information collected by the first voltage collection module is the first voltage information; When the voltage open circuit module is in a load disconnection state, the voltage information collected by the first voltage collection module is the third voltage information.

[0051] It should be noted that the first voltage acquisition module is used to measure the voltage value at both ends of the positive and negative electrodes of the lithium-ion battery. When the voltage open circuit module is in a load connected state, the measured voltage value is the first voltage information. When the voltage open circuit module is in a load disconnected state, the measured voltage value is the third voltage information.

[0052] According to an embodiment of the present invention, the second voltage acquisition module further includes: A second voltage information acquisition and recording unit, used for acquiring and recording the second voltage information to obtain a first voltage sequence; A voltage integration unit, used for performing voltage integration according to the first voltage sequence to obtain a voltage integration value; The peak-to-peak value unit is used to obtain the voltage peak-to-peak value according to the first voltage sequence analysis.

[0053] It should be noted that the second voltage information acquisition and recording unit is used to acquire and record the input voltage to obtain the first voltage sequence. The voltage integration unit is used to calculate the voltage integration value according to the set quantity. The peak-to-peak value unit is used to analyze the first voltage sequence to obtain the peak-to-peak value of the input voltage.

[0054] The present invention provides a lithium-ion battery SOC correction method and system. According to the characteristic that a UPS is in a high-power state for a long time, first power information of the lithium-ion battery is obtained. When the first power information exceeds a preset first power threshold, first voltage information of the lithium-ion battery is obtained. According to the first voltage information and the first power information, it is judged whether to enter a lithium-ion battery SOC correction mode; when entering the correction mode, it is judged according to the second voltage information whether the second voltage information is in a stable state. If so, the battery is switched to an open-circuit state according to a preset first time period, and the second power information is calculated according to the third voltage information to correct the first power information. According to the characteristic that a UPS is in a high-power state for a long time, the present invention calculates the power by the open-circuit voltage to correct the lithium-ion battery SOC, thereby improving the correction efficiency of the lithium-ion battery SOC.

[0055] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, and other media that can store program codes.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A lithium-ion battery SOC correction method, applied to a lithium-ion battery UPS, characterized in that: The method comprises: Acquire first power information; Determining whether the first power information exceeds a preset first power threshold; If yes, obtaining first voltage information; determining whether to enter a correction mode according to the first power information and the first voltage information; If yes, obtaining second voltage information; determining, according to the second voltage information, whether the second voltage information is in a stable state; If so, switching the battery to an open circuit state according to a preset first time period; Acquiring third voltage information; Obtaining second power information according to the third voltage information; The first power information is corrected according to the second power information.

2. A lithium-ion battery SOC correction method according to claim 1, applied to a lithium-ion battery UPS, characterized in that: The determining whether to enter the correction mode according to the first power information and the first voltage information is specifically: According to the first voltage information, searching a set first power correspondence table to obtain third power information; Calculating a difference between the first power information and the third power information to obtain first power difference information; Determining whether the first power difference information exceeds a preset first power difference threshold; If so, enter correction mode; If not, the correction mode is not entered.

3. The lithium-ion battery SOC correction method according to claim 1 is applied to a lithium-ion battery UPS, characterized in that: The determining, according to the second voltage information, whether the second voltage information is in a stable state is specifically: Obtaining a first voltage sequence according to the second voltage information; obtaining first quantity information; Obtain at least two fourth voltage information according to the first voltage sequence and the first quantity information; Obtaining first deviation information according to the fourth voltage information; Determining whether the first deviation information is lower than a preset deviation threshold; If not, it is determined that the second voltage information is in an unstable state; If so, a first peak-to-peak value is obtained according to the first voltage sequence; Determining whether the first peak-to-peak value exceeds a preset peak-to-peak value threshold; If yes, it is determined that the second voltage information is in a stable state; If not, it is determined that the second voltage information is in an unstable state.

4. A lithium-ion battery SOC correction method according to claim 1, applied to a lithium-ion battery UPS, characterized in that: The obtaining of the second power information according to the first voltage information is specifically: Acquiring first temperature information; Determining a first open circuit voltage relationship according to the first temperature information; The second electric quantity information is obtained according to the first open circuit voltage relationship and the first voltage information.

5. The lithium-ion battery SOC correction method according to claim 1 is applied to a lithium-ion battery UPS, characterized in that: The modifying the first power information according to the second power information is specifically: Obtaining second power difference information according to a difference between the second power information and the first power information; Determining whether the second power difference information exceeds a preset second power difference threshold; If yes, setting the first power information according to the second power information; If not, the first power correspondence table is updated according to the second power information.

6. A lithium-ion battery SOC correction method according to claim 4, applied to a lithium-ion battery UPS, characterized in that: Also includes: According to the first time period, acquiring at least two second power information to obtain a first power sequence; Determining first power deviation information according to the first power sequence; Determining whether the first power deviation information is lower than a preset power deviation threshold; If yes, then calculating the mean of the first power sequence to correct the first power information; If not, clear the first power sequence.

7. A lithium-ion battery SOC correction system, applied to a lithium-ion battery SOC correction method according to any one of claims 1 to 6, characterized in that: The system comprises: Processor, first voltage acquisition module, second voltage acquisition module, power recording module, voltage open circuit module; The processor is used to enter a correction mode according to first voltage information collected by a first voltage collection module, decide to perform a correction operation according to second voltage information collected by a second voltage collection module, adjust the connection state between the lithium-ion battery and the load through a voltage open circuit module, and update the first power information recorded by a power recording module.

8. A lithium-ion battery SOC correction system according to claim 7, characterized in that: The voltage open circuit module is specifically: The state is switched between a load connection state and a load disconnection state according to a control signal of a processor.

9. A lithium-ion battery SOC correction system according to claim 7, characterized in that: The first voltage acquisition module is specifically: When the voltage open circuit module is in a load connection state, the voltage information collected by the first voltage collection module is the first voltage information; When the voltage open circuit module is in a load disconnected state, the voltage information collected by the first voltage collection module is the third voltage information.

10. A lithium-ion battery SOC correction system according to claim 7, characterized in that: The second voltage acquisition module further includes: A second voltage information acquisition and recording unit, used for acquiring and recording the second voltage information to obtain a first voltage sequence; A voltage integration unit, used for performing voltage integration according to the first voltage sequence to obtain a voltage integration value; The peak-to-peak value unit is used to obtain the voltage peak-to-peak value according to the first voltage sequence analysis.

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