A lithium-ion battery SOC correction method and system

Abstract

The present invention provides a lithium-ion battery SOC correction method and system. Based on 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. Based on the first voltage information and the first power information, it is determined whether to enter a lithium-ion battery SOC correction mode. When entering the correction mode, it is determined based on 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 second power information is calculated based on third voltage information to correct the first power information. Based on the characteristic that a UPS is in a high-power state for a long time, the present invention calculates the power by open-circuit voltage to correct the lithium-ion battery SOC, thereby improving the correction efficiency of the lithium-ion battery SOC.

Description

Technical Field

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

[0002] SOC (State of Charge) is the state of charge of a lithium-ion battery, reflecting the current remaining charge level in the battery, also known as the remaining capacity. A lithium-ion battery's SOC is closely related to its voltage level. When the SOC approaches 100%, the battery's voltage gradually rises until it reaches the fully charged state (Fully Charged). Conversely, when the SOC approaches 0%, the battery's voltage gradually decreases until it reaches the cut-off voltage (Cut-off Voltage). Therefore, accurately monitoring the SOC of a lithium-ion battery is crucial to prevent the negative impacts of overcharging and discharging on the battery's lifespan.

[0003] As a core IT device, uninterruptible power supplies (UPS) play a crucial role in ensuring the power supply security required for the normal operation of data centers. When the power grid experiences various faults, the UPS uses its batteries to convert AC power to high-quality power, preventing data loss or mission interruptions caused by power outages. UPSs are emergency power supplies, and batteries are subject to power consumption and natural discharge, requiring correction to determine the SOC of lithium-ion batteries. Therefore, a lithium-ion battery SOC correction technology that automatically corrects SOC is urgently needed. Summary of the Invention

[0004] In view of the above problems, the object of the present invention is to provide a lithium-ion battery SOC correction method and system. According to the characteristic of UPS being 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 based on 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 based on 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 based on the third voltage information to correct the first power information. According to the characteristic of UPS being in a high-power state for a long time, the present invention calculates the power through 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 method for correcting the SOC of a lithium-ion battery, the method comprising:

[0006] Acquiring first power information;

[0007] Determining whether the first power information exceeds a preset first power threshold;

[0008] If yes, obtaining first voltage information;

[0009] determining whether to enter a correction mode according to the first power information and the first voltage information;

[0010] If yes, obtaining second voltage information;

[0011] determining, according to the second voltage information, whether the second voltage information is in a stable state;

[0012] If so, switching the battery to an open circuit state according to a preset first time period;

[0013] obtaining third voltage information;

[0014] Obtaining second power information according to the third voltage information;

[0015] Correct the first power information according to the second power information.

[0016] In this solution, the determination of whether to enter the correction mode based on the first power information and the first voltage information is specifically as follows:

[0017] According to the first voltage information, searching a set first power correspondence table to obtain third power information;

[0018] Calculating a difference between the first power information and the third power information to obtain first power difference information;

[0019] Determining whether the first power difference information exceeds a preset first power difference threshold;

[0020] If so, enter the correction mode;

[0021] If not, the correction mode will not be entered.

[0022] In this solution, the determining whether the second voltage information is in a stable state according to the second voltage information is specifically as follows:

[0023] obtaining a first voltage sequence according to the second voltage information;

[0024] obtaining first quantity information;

[0025] obtaining at least two fourth voltage information according to the first voltage sequence and the first quantity information;

[0026] obtaining first deviation information according to the fourth voltage information;

[0027] Determining whether the first deviation information is lower than a preset deviation threshold;

[0028] If not, it is determined that the second voltage information is in an unstable state;

[0029] If so, a first peak-to-peak value is obtained according to the first voltage sequence;

[0030] determining whether the first peak-to-peak value exceeds a preset peak-to-peak value threshold;

[0031] If yes, it is determined that the second voltage information is in a stable state;

[0032] If not, it is determined that the second voltage information is in an unstable state.

[0033] In this solution, the second power information is obtained according to the first voltage information, specifically:

[0034] obtaining first temperature information;

[0035] determining a first open circuit voltage relationship according to the first temperature information;

[0036] Second power information is obtained according to the first open-circuit voltage relationship and the first voltage information.

[0037] In this solution, the first power information is modified according to the second power information, specifically:

[0038] obtaining second power difference information according to a difference between the second power information and the first power information;

[0039] Determining whether the second power difference information exceeds a preset second power difference threshold;

[0040] If so, setting the first power information according to the second power information;

[0041] If not, update the first power correspondence table according to the second power information.

[0042] This plan also includes:

[0043] Acquire at least two pieces of second power information according to the first time period to obtain a first power sequence;

[0044] determining first power deviation information according to the first power sequence;

[0045] Determining whether the first power deviation information is lower than a preset power deviation threshold;

[0046] If yes, calculate the mean of the first power sequence to correct the first power information;

[0047] If not, clear the first power sequence.

[0048] A second aspect of the present invention provides a lithium-ion battery SOC correction system, characterized in that the system includes:

[0049] Processor, first voltage acquisition module, second voltage acquisition module, power recording module, voltage open circuit module;

[0050] The processor is used to enter a correction mode based on the first voltage information collected by the first voltage acquisition module, decide to perform a correction operation based on the second voltage information collected by the second voltage acquisition module, adjust the connection status between the lithium-ion battery and the load through the voltage open circuit module, and update the first power information recorded by the power recording module.

[0051] In this solution, the voltage open circuit module is specifically:

[0052] The system switches between a load connected state and a load disconnected state according to a control signal from a processor.

[0053] In this solution, the first voltage acquisition module is specifically:

[0054] When the voltage open circuit module is in a load connection state, the voltage information collected by the first voltage collection module is first voltage information;

[0055] When the voltage open circuit module is in a load disconnected state, the voltage information collected by the first voltage collection module is third voltage information.

[0056] In this solution, the second voltage acquisition module further includes:

[0057] a second voltage information collecting and recording unit, configured to collect and record the second voltage information to obtain a first voltage sequence;

[0058] a voltage integration unit, configured to perform voltage integration according to the first voltage sequence to obtain a voltage integration value;

[0059] The peak-to-peak value unit is used to obtain a voltage peak-to-peak value according to the first voltage sequence analysis.

[0060] The present invention provides a lithium-ion battery SOC correction method and system. Based on 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. Based on the first voltage information and the first power information, it is determined whether to enter a lithium-ion battery SOC correction mode. When entering the correction mode, it is determined based on 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 second power information is calculated based on third voltage information to correct the first power information. Based on the characteristic that a UPS is in a high-power state for a long time, the present invention calculates the power by 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

[0061] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope.

[0062] Figure 1 A flow chart showing a method for correcting SOC of a lithium-ion battery according to the present invention is shown;

[0063] Figure 2 A flowchart of entering a correction mode according to an embodiment of the present invention is shown;

[0064] Figure 3 A flowchart showing whether the second voltage information provided by an embodiment of the present invention is in a stable state is shown;

[0065] Figure 4 A block diagram of a lithium-ion battery SOC correction system according to the present invention is shown. DETAILED DESCRIPTION

[0066] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0067] Unless otherwise defined, all terms (including technical and scientific terms) used in the embodiments of the present invention have the same meaning 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 explicitly defined in this manner in the embodiments of the present invention.

[0068] The words "first", "second" and similar terms 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" do not indicate a quantity limitation, but rather indicate the existence of at least one. Similarly, words such as "include" or "comprise" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" 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 do not necessarily have to be performed in exact order. On the contrary, the various steps may be processed in reverse order or simultaneously. At the same time, other operations may be added to these processes, or one or more steps may be removed from these processes.

[0069] 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.

[0070] Figure 1 A flow chart of a lithium-ion battery SOC correction method according to the present invention is shown.

[0071] like Figure 1 As shown, the first aspect of the present invention discloses a method for correcting the SOC of a lithium-ion battery, the method comprising:

[0072] S102, obtaining first power information;

[0073] S104, determining whether the first power information exceeds a preset first power threshold;

[0074] S106, if yes, obtain first voltage information;

[0075] S108, determining whether to enter a correction mode based on the first power information and the first voltage information;

[0076] S110, if yes, obtain second voltage information;

[0077] S112, determining whether the second voltage information is in a stable state according to the second voltage information;

[0078] S114, if yes, switching the battery to an open circuit state according to a preset first time period;

[0079] S116, obtaining third voltage information;

[0080] S118, obtaining second power information according to the third voltage information;

[0081] S120: Modify the first power information according to the second power information.

[0082] 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.

[0083] In this embodiment, because the UPS is in a high-charge state for extended periods, the SOC of the lithium-ion battery is corrected when the battery is in a high-charge state. When the first charge information exceeds a preset first charge threshold, indicating that the battery has reached a preset correction charge requirement, an initial determination is made based on the first voltage information of the lithium-ion battery. A corresponding charge value is retrieved based on the first voltage information. When the difference between the retrieved charge value and the first charge information exceeds a preset tolerance, it indicates that the SOC deviation of the lithium-ion battery is significant, requiring a correction mode to correct the SOC of the lithium-ion battery. During SOC correction, the lithium-ion battery and the load are disconnected for a brief period, typically on the order of milliseconds. Therefore, to ensure that the UPS can maintain power and maintain continuous power outages for the load, this embodiment first detects the stability of the second voltage information, i.e., the stability of the input power supply. Only when the second voltage information is stable is the battery switched to an open-circuit state for a 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, i.e., the third voltage information, is measured. The second power information is then calculated based on the open-circuit voltage-power-unit relationship, i.e., the OCV relationship. Finally, when the deviation between the first power information and the second power information exceeds a preset tolerance, indicating that the lithium-ion battery's SOC needs to be corrected, the first power information is set based on the second power information to achieve the effect of correcting the lithium-ion battery's SOC. This embodiment, based on the characteristic of a UPS being in a high-power state for extended periods of time, calculates the power level from the open-circuit voltage to correct the lithium-ion battery's SOC. This improves the efficiency of correcting the lithium-ion battery's SOC while ensuring uninterrupted power supply to the load.

[0084] Figure 2 A flow chart of entering the correction mode provided by an embodiment of the present invention is shown.

[0085] According to an embodiment of the present invention, Figure 2 As shown, the determination of whether to enter the correction mode according to the first power information and the first voltage information is specifically as follows:

[0086] S202, searching a set first power correspondence table based on the first voltage information to obtain third power information;

[0087] S204, calculating a difference between the first power information and the third power information to obtain first power difference information;

[0088] S206, determining whether the first power difference information exceeds a preset first power difference threshold;

[0089] S208, if yes, enter correction mode;

[0090] S210: If not, then do not enter the correction mode.

[0091] It should be noted that the first power correspondence table is a table of correspondence between voltage and power when the lithium-ion battery is connected to the load. In this embodiment, the first power correspondence table recorded by each lithium-ion battery is first searched based on 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 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 represents the difference between the lithium-ion battery SOC recorded value and the SOC calculated value. 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.

[0092] Figure 3 A flowchart for determining whether the second voltage information provided by an embodiment of the present invention is in a stable state is shown.

[0093] According to an embodiment of the present invention, Figure 3 As shown, the determining whether the second voltage information is in a stable state according to the second voltage information is specifically as follows:

[0094] S302, obtaining a first voltage sequence according to the second voltage information;

[0095] S304, obtaining first quantity information;

[0096] S306, obtaining at least two fourth voltage information according to the first voltage sequence and the first quantity information;

[0097] S308, obtaining first deviation information according to the fourth voltage information;

[0098] S310, determining whether the first deviation information is lower than a preset deviation threshold;

[0099] S312, if not, determining that the second voltage information is in an unstable state;

[0100] S314, if yes, obtain a first peak-to-peak value according to the first voltage sequence;

[0101] S316, determining whether the first peak-to-peak value exceeds a preset peak-to-peak value threshold;

[0102] S318: If yes, it is determined that the second voltage information is in a stable state;

[0103] S312: If not, it is determined that the second voltage information is in an unstable state.

[0104] 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 number of voltages 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 and minimum values 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 of the fourth voltage information; the first peak-to-peak value is the difference between the maximum and minimum values in the first voltage sequence within the same input power cycle.

[0105] In this embodiment, the stability of the UPS's input power supply is determined to avoid performing SOC corrections when the power supply is unstable, which could result in a risk of load power outages. Typically, in practical applications, the UPS's input power supply is AC power, i.e., 220 volts AC. This embodiment continuously collects and records the voltage values of the input power supply over a set time period to obtain a first voltage sequence. According to a preset voltage integral value calculation method, the voltage values in the first voltage sequence are extracted based on a set first quantity information to calculate a voltage integral value, i.e., fourth voltage information. Based on the calculated voltage integral values, the deviation between the voltage integral values is calculated to obtain first deviation information. A determination is made as to whether the first deviation information is lower than a preset deviation threshold. If not, this indicates that the output deviation of the input power supply is large, i.e., the input power supply is deemed to have poor stability. If so, this indicates that the output deviation of the input power supply is small. In this case, the peak-to-peak value of the input power supply is detected to determine whether the input power supply meets the supply voltage requirements. 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.

[0106] According to an embodiment of the present invention, obtaining the second power information according to the third voltage information is specifically:

[0107] obtaining first temperature information;

[0108] determining a first open circuit voltage relationship according to the first temperature information;

[0109] Second power information is obtained according to the first open-circuit voltage relationship and the third voltage information.

[0110] It should be noted that because battery temperature affects internal resistance, varying temperatures will affect the voltage-based charge value. In this embodiment, an OCV equation corresponding to the temperature is selected to calculate the charge value based on the voltage. The first temperature information is the temperature of the lithium-ion battery. Based on the first temperature information, a first open-circuit voltage equation corresponding to the temperature, i.e., the OCV equation, is searched and selected. Then, based on the third voltage information and the OCV equation, the second charge value is calculated as the SOC correction value.

[0111] According to an embodiment of the present invention, the first power information is modified according to the second power information, specifically:

[0112] obtaining second power difference information according to a difference between the second power information and the first power information;

[0113] Determining whether the second power difference information exceeds a preset second power difference threshold;

[0114] If so, setting the first power information according to the second power information;

[0115] If not, update the first power correspondence table according to the second power information.

[0116] It should be noted that, in this embodiment, the SOC recorded value is corrected or the first power correspondence table is updated based on the difference between the SOC correction value and the SOC recorded value. Based on 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 a 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 lithium-ion battery SOC correction; 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.

[0117] According to an embodiment of the present invention, the further embodiment includes:

[0118] Acquire at least two pieces of second power information according to the first time period to obtain a first power sequence;

[0119] determining first power deviation information according to the first power sequence;

[0120] Determining whether the first power deviation information is lower than a preset power deviation threshold;

[0121] If yes, calculate the mean of the first power sequence to correct the first power information;

[0122] If not, clear the first power sequence.

[0123] It should be noted that to improve the accuracy of SOC correction, in this embodiment, a first power sequence is obtained by acquiring at least two second power information items based on a first time period, which is used to calculate first power deviation information. The first power deviation information represents the stability of the SOC correction value obtained from multiple measurements. A determination is made as to whether the first power deviation information is lower than a preset power deviation threshold. If so, the SOC correction value is stable and can be used to correct the current recorded SOC value. If not, an anomaly exists in the measurement and calculation of the SOC correction value, and the first power sequence is cleared, and the SOC correction value is remeasured.

[0124] It is worth mentioning that it also includes:

[0125] Obtain charging and discharging record information;

[0126] Obtaining second number information according to the charge and discharge record information;

[0127] determining first revised weight information according to the second number information;

[0128] The second power information is corrected according to the first correction weight information.

[0129] It should be noted that the second number of times information refers to the number of charge and discharge cycles of the lithium-ion battery. In this embodiment, the number of charge and discharge cycles of the lithium-ion battery is used to indicate the degree of aging of the lithium-ion battery. The second power information is then corrected based on the degree of aging, i.e., the SOC correction value is adjusted. First, based on the second number of times information, a table is used to determine first correction weight information. Then, based on the first correction weight information, the second power information is corrected.

[0130] It is worth mentioning that it also includes:

[0131] Obtain charging and discharging record information;

[0132] Sending the charge and discharge record information to a neural network model to obtain a second open circuit voltage relationship;

[0133] The first open circuit voltage relationship equation is set according to the second open circuit voltage relationship equation.

[0134] It should be noted that the charging records include, but are not limited to, the charge / discharge start power, charge / discharge end power, or charge / discharge time. The charging records are sent to the neural network model, which, based on the usage of the lithium-ion battery, outputs a correction equation for the OCV that conforms to the actual operating conditions of the lithium-ion battery, namely, the second open-circuit voltage equation, which is used to set the first open-circuit voltage equation.

[0135] It is worth mentioning that it also includes:

[0136] Determine when the UPS is in charging state;

[0137] Acquiring first voltage information and first current information;

[0138] Determining whether the first voltage information reaches a preset first voltage threshold;

[0139] If so, determining whether the first current information exceeds a preset first current threshold;

[0140] If not, determining whether the first power information is a preset power upper limit value;

[0141] If not, enter the correction mode.

[0142] It should be noted that this embodiment sets a rule for triggering a correction mode when fully charged, that is, when the lithium-ion battery switches to a fully charged state during charging, it automatically enters a correction mode based on the power level. The first current information is the charging current of the lithium-ion battery. When the voltage value at the positive and negative terminals of the lithium-ion battery, that is, the first voltage information, exceeds a preset first voltage threshold, it indicates that the voltage value of the lithium-ion battery has reached a 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; if the lithium-ion battery is already in a fully charged voltage state and the charging current does not exceed the minimum charging current, it can be determined that the lithium-ion battery is in a fully charged state. At this time, if the power level of the lithium-ion battery does not exceed the preset upper limit of the charging power level, it automatically enters the correction mode, triggering the SOC correction operation of the lithium-ion battery.

[0143] Figure 4 A block diagram of a lithium-ion battery SOC correction system according to the present invention is shown.

[0144] like Figure 4 As shown, the second aspect of the present invention discloses a lithium-ion battery SOC correction system, the system comprising:

[0145] Processor 401, first voltage acquisition module 402, second voltage acquisition module 403, power recording module 404, voltage open circuit module 405;

[0146] The processor is used to enter a correction mode based on the first voltage information collected by the first voltage acquisition module, decide to perform a correction operation based on the second voltage information collected by the second voltage acquisition module, adjust the connection status between the lithium-ion battery and the load through the voltage open circuit module, and update the first power information recorded by the power recording module.

[0147] 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 status 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.

[0148] According to an embodiment of the present invention, the voltage open circuit module is specifically:

[0149] The system switches between a load connected state and a load disconnected state according to a control signal from a processor.

[0150] It should be noted that in this embodiment, the voltage open circuit module is a circuit device such as an analog switch or relay, which can switch the connection state of the circuit 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.

[0151] According to an embodiment of the present invention, the first voltage acquisition module is specifically:

[0152] When the voltage open circuit module is in a load connection state, the voltage information collected by the first voltage collection module is first voltage information;

[0153] When the voltage open circuit module is in a load disconnected state, the voltage information collected by the first voltage collection module is third voltage information.

[0154] It should be noted that the first voltage acquisition module is used to measure the voltage value at the positive and negative terminals of the lithium-ion battery. When the voltage open circuit module is in the load-connected state, the measured voltage value is the first voltage information. When the voltage open circuit module is in the load-disconnected state, the measured voltage value is the third voltage information.

[0155] According to an embodiment of the present invention, the second voltage acquisition module further includes:

[0156] a second voltage information collecting and recording unit, configured to collect and record the second voltage information to obtain a first voltage sequence;

[0157] a voltage integration unit, configured to perform voltage integration according to the first voltage sequence to obtain a voltage integration value;

[0158] The peak-to-peak value unit is used to obtain a voltage peak-to-peak value according to the first voltage sequence analysis.

[0159] It should be noted that the second voltage information acquisition and recording unit is used to acquire and record the input voltage to obtain a first voltage sequence. The voltage integration unit is used to calculate the voltage integral value according to a 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.

[0160] The present invention provides a lithium-ion battery SOC correction method and system. Based on 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. Based on the first voltage information and the first power information, it is determined whether to enter a lithium-ion battery SOC correction mode. When entering the correction mode, it is determined based on 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 second power information is calculated based on third voltage information to correct the first power information. Based on the characteristic that a UPS is in a high-power state for a long time, the present invention calculates the power by open-circuit voltage to correct the lithium-ion battery SOC, thereby improving the correction efficiency of the lithium-ion battery SOC.

[0161] If the functions are implemented as software 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 portion that contributes to the prior art, or the portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes 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 various media capable of storing program code, such as USB flash drives, mobile hard drives, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical disks.

[0162] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection 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: According to the characteristic that the UPS is in a high power state for a long time, when the lithium-ion battery is in a high power state, obtaining first power information; Determining whether the first power information exceeds a preset first power threshold; If yes, obtain first voltage information, where the first voltage information is the voltage value at the positive and negative terminals of the lithium-ion battery; determining whether to enter a correction mode according to the first power information and the first voltage information; If yes, obtain second voltage information, where the second voltage information is the input power voltage of the UPS; 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; Acquire third voltage information, where the third voltage information is an open circuit voltage value at both ends of the positive and negative electrodes of the lithium-ion battery; obtaining first temperature information; determining a first open circuit voltage relationship according to the first temperature information; Obtaining second power information according to the first open-circuit voltage relationship and the third voltage information; Correcting the first power information according to the second power information; The determining, based on the second voltage information, whether the second voltage information is in a stable state is specifically as follows: Obtaining a first voltage sequence according to the second voltage information, where the first voltage sequence is a sequence composed of the second voltage information collected according to a preset period; Acquire first quantity information, where the first quantity information is a voltage quantity used to calculate a voltage integral value; Obtain at least two fourth voltage information according to the first voltage sequence and the first quantity information, wherein the fourth voltage information is a voltage integral value obtained according to a preset voltage integral calculation method; Obtaining first deviation information according to the fourth voltage information, where the first deviation information is a deviation value between all 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; The relationship formula for determining the first open circuit voltage is specifically: 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; According to the second open circuit voltage relationship formula, setting the first open circuit voltage relationship formula; The step of correcting the first power information according to the second power information is as follows: 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 so, setting the first power information according to the second power information; If not, update the first power correspondence table 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 the correction mode; If not, the correction mode is not entered.

3. The lithium-ion battery SOC correction method according to claim 1, applied to a lithium-ion battery UPS, is characterized in that: Also includes: Acquire at least two pieces of second power information according to the first time period 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, calculate the mean of the first power sequence to correct the first power information; If not, clear the first power sequence.

4. A lithium-ion battery SOC correction system, applied to a lithium-ion battery SOC correction method according to any one of claims 1 to 3, 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 based on the first voltage information collected by the first voltage acquisition module, decide to perform a correction operation based on the second voltage information collected by the second voltage acquisition module, adjust the connection status between the lithium-ion battery and the load through the voltage open circuit module, and update the first power information recorded by the power recording module.

5. A lithium-ion battery SOC correction system according to claim 4, characterized in that: The voltage open circuit module is specifically: The system switches between a load connected state and a load disconnected state according to a control signal from a processor.

6. A lithium-ion battery SOC correction system according to claim 4, 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 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 third voltage information.

7. The lithium-ion battery SOC correction system according to claim 4, characterized in that: The second voltage acquisition module further includes: a second voltage information collecting and recording unit, configured to collect and record the second voltage information to obtain a first voltage sequence; a voltage integration unit, configured to perform voltage integration according to the first voltage sequence to obtain a voltage integration value; The peak-to-peak value unit is used to obtain a voltage peak-to-peak value according to the first voltage sequence analysis.

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