Battery management method and system and computer program product

Abstract

The invention provides a battery management method and system and a computer program product, and belongs to the technical field of batteries. The method comprises the steps of monitoring temperature and voltage of a battery in real time; adjusting the discharge cut-off voltage of the battery according to the temperature of the battery; when the temperature of the battery is lower than a preset low-temperature judgment threshold value, correcting a calculation mode of the SOC of the battery; and in response to the condition that the SOC of the current battery is lower than a preset value and the difference value between the voltage of the battery and the current discharge cut-off voltage is smaller than a preset voltage difference, limiting the discharge current of the battery according to the difference value between the voltage of the battery and the current discharge cut-off voltage. The system comprises a battery state detection module, a cut-off voltage adjustment module, an SOC correction module and a battery management module. By correcting the SOC of the battery, the SOC of the battery in the low-temperature state is rapidly reduced, dynamic correction of the discharging tail end of the battery at the low temperature is effectively avoided, and the capacity of the battery is fully utilized. And through a discharge tail end protection mechanism, the occurrence of an under-voltage fault of the battery is effectively prevented, and the use safety of the equipment is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and particularly to a battery management method, system and computer program product. Background Art

[0002] In a low-temperature environment in winter, the available capacity of the battery will significantly decrease, and problems such as jumps in the dynamic correction of SOC (State of Charge) will occur at the end of discharge.

[0003] Traditional Battery Management Systems (BMS) usually adopt fixed discharge cut-off voltages and SOC estimation methods for low-temperature capacity retention rate, which are difficult to accurately reflect the true state of the battery at low temperatures and are prone to the following problems: the internal resistance of the battery increases at low temperatures, the discharge platform voltage decreases, and the traditional SOC estimation method will overestimate the actual capacity of the battery, resulting in an increase in SOC estimation error. When the battery approaches the discharge cut-off voltage, the BMS will perform dynamic correction to forcefully reduce the SOC, resulting in a further reduction in the available capacity of the battery and causing user complaints. Due to the influence of SOC estimation error and dynamic correction, the battery may be determined to be under-voltage before reaching the actual discharge cut-off voltage, triggering the protection mechanism and causing the vehicle to break down unexpectedly. Summary of the Invention

[0004] The purpose of the present invention is to provide a battery management method, system and computer program product, which avoid the dynamic correction at the end of battery discharge at low temperatures, effectively prevent the occurrence of battery under-voltage faults, and improve the use safety of the device.

[0005] To achieve the above purpose, the present invention provides the following technical solutions in one aspect:

[0006] A battery management method includes the following steps: real-time monitoring the temperature and voltage of the battery; adjusting the discharge cut-off voltage of the battery according to the temperature of the battery; when the temperature of the battery is lower than a preset low-temperature judgment threshold, correcting the calculation method of the SOC of the battery; in response to the current SOC of the battery being lower than a preset value and the difference between the voltage of the battery and the current discharge cut-off voltage being less than a preset voltage difference, restricting the discharge current of the battery according to the difference between the voltage of the battery and the current discharge cut-off voltage.

[0007] Further, limiting the discharge current of the battery according to the difference between the voltage of the battery and the current discharge cut-off voltage includes: when the difference between the voltage of the battery and the current discharge cut-off voltage is less than a preset voltage difference but greater than 0, making the discharge current of the battery decrease as the difference decreases; when the voltage of the battery is equal to the discharge cut-off voltage, issuing a loop cut-off instruction, and the loop cut-off instruction is used to cut off the discharge loop of the battery.

[0008] Further, when the temperature of the battery is lower than a preset low-temperature judgment threshold, modifying the calculation method of the SOC of the battery includes: calculating the loss coefficient of the battery according to the temperature of the battery; calculating the SOC discharge loss value of the battery according to the loss coefficient of the battery; and correcting the battery SOC based on the SOC discharge loss value of the battery.

[0009] Further, after calculating the SOC discharge loss value of the battery according to the loss coefficient of the battery, it further includes: judging the magnitude of the SOC discharge loss value and the upper limit value of the preset SOC discharge loss value; when the SOC discharge loss value exceeds the upper limit value, taking the upper limit value as the SOC discharge loss value.

[0010] Further, calculating the loss coefficient of the battery according to the temperature of the battery includes: judging the temperature range corresponding to the temperature of the battery according to the temperature of the battery and a preset temperature range; determining the loss coefficient corresponding to the temperature of the battery according to the temperature range corresponding to the temperature of the battery and preset relationship data, and the relationship data is the relationship data corresponding to the temperature range and the loss coefficient.

[0011] Further, the formula for calculating the SOC discharge loss value of the battery according to the loss coefficient of the battery is:

[0012] SOC discharge loss value = ∫I 放 *Sxdt 放 / C 额定容量

[0013] where, i 放 is the output current value of the battery, t 放 is the duration of the battery discharging at a current magnitude of i 放 C 额定容量 is the rated capacity of the battery, and Sx is the loss coefficient of the battery.

[0014] Further, the formula for correcting the battery SOC according to the SOC discharge loss value of the battery is: SOC 修正后 =(SOC 常温状态 -(SOC 低温冻结 +SOC放电损耗值 )) / (100% - (SOC 低温冻结 + SOC 放电损耗值 )); where SOC 低温冻结 = 100% - the capacity retention rate of the battery.

[0015] Further, after correcting the SOC of the battery based on the SOC discharge loss value of the battery, the following steps are further included: when it is detected that the battery is in a charging condition, release the SOC discharge loss value of the battery according to the magnitude of the charging current of the battery over time; when the SOC discharge loss value of the battery is completely released, adjust the calculation method of the SOC to a normal calculation method, and the calculation method of the SOC of the battery is not corrected under the normal calculation method.

[0016] On the other hand, a battery management system is provided, including: a battery state detection module that monitors the temperature and voltage of the battery in real time; a cut-off voltage adjustment module that adjusts the discharge cut-off voltage of the battery according to the temperature of the battery; an SOC correction module that corrects the calculation method of the SOC of the battery when the temperature of the battery is lower than a preset low-temperature judgment threshold; a battery management module that, in response to the current SOC of the battery being lower than a preset value and the difference between the voltage of the battery and the current discharge cut-off voltage being less than a preset voltage difference, limits the discharge current of the battery according to the difference between the voltage of the battery and the current discharge cut-off voltage.

[0017] On yet another hand, an electronic device is provided, which includes: a processor and a memory for storing executable instructions of the processor; wherein, the processor is configured to execute the above battery management method.

[0018] On still another hand, a computer-readable storage medium is provided, in which at least one instruction, at least one program, a code set or an instruction set is stored, and the at least one instruction, at least one program, the code set or the instruction set is loaded and executed by a processor to implement the above battery management method.

[0019] On yet another hand, a computer program product containing instructions is provided, and when the computer program product runs on a computer, the above battery management method is executed by the computer.

[0020] Analysis shows that the present invention improves the accuracy of battery SOC estimation: through temperature compensation and model correction, the SOC estimation error at low temperatures is reduced, and the reliability of the battery management system is improved. In addition, it can also prevent dynamic correction at the end of discharge and battery SOC jump: by correcting the battery SOC, the battery SOC under low-temperature conditions drops rapidly, effectively avoiding dynamic correction at the end of battery discharge at low temperatures and making full use of the battery capacity. And through the end-of-discharge protection mechanism, the occurrence of battery undervoltage faults is effectively prevented, and the use safety of the device is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0022] Figure 1 A schematic flowchart of a battery management method provided by an embodiment of the present invention;

[0023] Figure 2 A schematic flowchart of a calculation method for correcting the SOC of a battery provided by an embodiment of the present invention;

[0024] Figure 3 A schematic structural diagram of a battery management system provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. Each example is provided by way of explanation of the present invention rather than a limitation of the present invention. In fact, those skilled in the art will clearly understand that modifications and variations can be made to the present invention without departing from the scope or spirit of the present invention. For example, features shown or described as part of one embodiment can be used in another embodiment to yield yet another embodiment. Therefore, it is desirable that the present invention includes such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0026] In the description of the present invention, the orientation or positional relationship indicated by the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and does not require the present invention to be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. The terms "connected", "connected to", and "disposed" used in the present invention should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection; it can be directly connected or indirectly connected through an intermediate component; it can be a wired electrical connection, a radio connection, or a wireless communication signal connection. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0027] One or more examples of the present invention are shown in the accompanying drawings. The detailed description uses numerical and alphabetical labels to refer to features in the drawings. Similar or like labels in the drawings and the description have been used to refer to similar or like parts of the present invention. As used herein, terms such as "first", "second", "third", and "fourth" are used interchangeably to distinguish one component from another and are not intended to indicate the position or importance of individual components.

[0028] As Figure 1 shown, according to an embodiment of the present invention, a battery management method is provided, which includes the following steps:

[0029] Step S101, monitor the temperature and voltage of the battery in real time.

[0030] In this step, the temperature and voltage of the battery are obtained. The temperature of the battery can be obtained through a temperature sensor. For example, distributed thermistors are arranged in the battery module, which can be NTC (Negative Temperature Coefficient) thermistors. Usually, multiple temperature sensors are arranged in the battery. In this embodiment, the specific method for obtaining the temperature of the battery is not specifically limited. The lowest temperature measured among multiple temperature sensors can be used as the temperature of the battery. The voltage of the battery can be obtained through the analog front-end voltage acquisition port of the BMS.

[0031] Step S102, adjust the discharge cut-off voltage of the battery according to the temperature of the battery.

[0032] The discharge cut-off voltage of the battery is usually not fixed and varies with temperature. That is to say, the battery usually has corresponding relationship data between the discharge cut-off voltage and temperature. By querying this relationship data, the discharge cut-off voltage of the battery at different temperatures can be obtained, so as to adjust the discharge cut-off voltage of the battery according to the temperature (current temperature) of the battery and avoid over-discharge of the battery.

[0033] Step S103: When the temperature of the battery is lower than the preset low-temperature judgment threshold, correct the calculation method of the battery's state of charge (SOC).

[0034] In this step, compare the temperature of the battery (current temperature) with the preset low-temperature judgment threshold. When the temperature of the battery (current temperature) is lower than the preset low-temperature judgment threshold, it is determined that the battery is in a low-temperature environment, and then correct the calculation method of the battery's SOC. That is, correct the calculation method of the battery's SOC, adjusting from the original normal calculation method to a corrected calculation method. Under the corrected calculation method, correct the calculation method of the battery's SOC under the normal calculation method. When the temperature of the battery (current temperature) is not lower than the preset low-temperature judgment threshold, do not correct the calculation method of the battery's SOC, that is, adopt the normal calculation method, which does not involve the SOC discharge loss value of the battery and is the calculation method in the prior art, such as the ampere-hour integration method mentioned below. That is to say, when it is determined that the battery is in a low-temperature environment, use the SOC discharge loss value to correct the calculation method of the battery's SOC.

[0035] Among them, there is no limitation on the specific setting method of the low-temperature judgment threshold. For example: the configurable range of the typical low-temperature threshold of lithium iron phosphate / lithium nickel cobalt manganese oxide batteries is usually -30°C to 5°C. Therefore, the low-temperature judgment threshold can be set to: 2°C, 0°C, -2°C, etc.; in some usage scenarios, obtain the battery capacity attenuation curve at different temperatures through experiments, and set the temperature corresponding to a certain value of the capacity retention rate as the low-temperature judgment threshold, and this certain value can be confirmed according to the actual situation. In practical applications, the low-temperature judgment threshold is usually confirmed according to actual needs.

[0036] Specifically, as Figure 2 shown, the implementation method of this step includes but is not limited to the following steps:

[0037] Step S1031: Calculate the loss coefficient of the battery according to the temperature of the battery.

[0038] Specifically, determine the temperature range corresponding to the temperature of the battery (current temperature) according to the temperature of the battery (current temperature) and the preset temperature range, and determine the loss coefficient corresponding to the temperature of the battery (current temperature) according to the temperature range corresponding to the temperature of the battery (current temperature) and the preset relationship data. This relationship data is the relationship data between the temperature range and the loss coefficient. That is, set the temperature range; set the interval loss coefficient corresponding to each temperature range; calculate the loss coefficient of the battery based on the temperature of the battery, the temperature range where the battery's temperature is located, and the interval loss coefficient.

[0039] It can be understood that by refining the temperature partition and setting the loss coefficient of each partition, the estimation accuracy of the battery SOC in a low-temperature environment can be significantly improved.

[0040] Specifically, the above temperature range can be: -30°C to -20°C, -20°C to -10°C, -10°C to 0°C. If the temperature of the battery during discharge is within the above range, the loss coefficient corresponding to the temperature can be calculated by the linear interpolation method.

[0041] For example, the relational data is characterized in the form of a temperature loss coefficient table. If the loss coefficient corresponding to -30°C in the temperature loss coefficient table is 0.6 and the loss coefficient corresponding to -20°C is 0.4. When the battery temperature is detected to be -26°C, the method for calculating the loss coefficient of -26°C by looking up the table and linear interpolation is: (0.6 - Sx) / (0.6 - 0.4) = (-26 - (-30)) / (-20 - (-30)), and the loss coefficient Sx corresponding to -26°C is obtained as 0.52.

[0042] Step S1032, calculate the SOC discharge loss value of the battery according to the loss coefficient of the battery.

[0043] Specifically, the formula for calculating the SOC discharge loss value of the battery is:

[0044] SOC discharge loss value = ∫I 放 *Sxdt 放 / C 额定容量 (1)

[0045] Wherein, I 放 is the output current value of the battery discharge, unit: ampere, t 放 is the duration of the battery discharging with the current magnitude of I 放 for discharging, C 额定容量 is the rated capacity of the battery, and Sx is the loss coefficient of the battery.

[0046] After calculating the SOC discharge loss value of the battery according to the loss coefficient of the battery in the step, it further includes:

[0047] Judge the magnitude of the SOC discharge loss value and the upper limit value of the preset SOC discharge loss value. When the SOC discharge loss value exceeds the upper limit value, use the upper limit value as the SOC discharge loss value.

[0048] Specifically, an upper limit value needs to be set during the estimation of the battery SOC for the SOC discharge loss value. When reaching the upper limit value, the increase of the SOC discharge loss value is stopped. Usually, the upper limit value is taken as 0.10 - 0.20, such as 0.12, 0.15, 0.18, 0.20, preferably 0.15. The specific numerical value of the upper limit value is not limited in this embodiment.

[0049] It is understandable that setting this upper limit value is to match the maximum error of the SOC during the low-temperature discharge of the battery cell. Further, by reasonably setting the loss coefficient in the low-temperature environment, when the temperature reaches the upper limit of the low-temperature threshold, the SOC discharge loss value also exactly reaches the upper limit value.

[0050] Step S1033, correct the battery SOC based on the SOC discharge loss value of the battery.

[0051] Specifically, the formula for correcting the battery SOC according to the SOC discharge loss value of the battery is:

[0052] SOC 修正后 =(SOC 常温状态 -(SOC 低温冻结 +SOC discharge loss value)) / (100%-(SOC 低温冻结 +SOC 放电损耗值 )); where, SOC 低温冻结 =100%-capacity retention rate of the battery.

[0053] In the formula, SOC 修正后 represents the corrected battery SOC, SOC 常温状态 represents the battery SOC at normal temperature, SOC 低温冻结 represents the low-temperature frozen SOC, and the capacity retention rate of the battery is the capacity retention rate of the battery at the current temperature.

[0054] It is understandable that the above formula for correcting the battery SOC can be used as a correction model to correct the battery SOC.

[0055] Specifically, the correction process of the battery SOC is as follows: According to the monitored battery voltage, current, and temperature data, the ampere-hour integration method is used to estimate the battery SOC. When the detected temperature is less than the preset low-temperature threshold, the battery loss coefficient is queried according to the temperature, and the SOC discharge loss value of the battery is calculated. At the same time, since the battery will reduce the capacity retention rate at low temperature, the SOC discharge loss value is superimposed on the SOE (State of Energy, battery remaining energy) of the battery in the low-temperature state to accelerate the decline rate of the battery SOC at low temperature.

[0056] It is understandable that the capacity retention rate of the battery at the current temperature is obtained by dividing the current remaining dischargeable capacity (or battery remaining energy) of the battery by the available capacity of the battery at normal temperature. The lower the battery temperature, the lower the low-temperature capacity retention rate of the battery, making the SOC of the battery in the low-temperature environment drop faster, thus solving the problem of capacity attenuation of lithium batteries in the low-temperature environment.

[0057] Specifically, after step S103, the following steps are further included:

[0058] When it is detected that the battery is in the charging condition, release the SOC discharge loss value of the battery according to the magnitude of the charging current of the battery over time; after the SOC discharge loss value of the battery is completely released, adjust the calculation method of SOC to the normal calculation method. Under the normal calculation method, the calculation method of the SOC of the battery is not corrected, that is, the SOC discharge loss value is not involved, and the foregoing formula is not used for calculation. For example, the ampere-hour integration method is used for calculation.

[0059] It can be understood that the amount of electricity released during battery charging corresponds to the amount of electricity lost during discharging. Since this part of the electricity is not actually consumed, it needs to be released (compensated) during charging. Otherwise, the increase in the core temperature after charging will cause the calculated SOC of the battery to be too low.

[0060] The specific formula is: SOC charging loss value = ∫I 充 dt 充 / C 额定容量 (2)

[0061] Among them, I 充 is the input current value of the battery charging (unit: ampere), t 充 is the duration of the battery charging with the current magnitude of I 充 , and C 额定容量 is the rated capacity of the battery.

[0062] When the cumulative SOC discharge loss value calculated in formula (1) during the discharging process is completely released during the charging process in formula (2), the SOC charging loss calculation of formula (2) is no longer performed, and the normal charging SOC calculation is entered, that is, according to the monitored battery voltage, current and temperature data, the ampere-hour integration method is used to estimate the battery SOC.

[0063] Step S104, when the SOC of the battery is lower than the preset value and the difference between the battery voltage and the current discharge cut-off voltage is less than the preset voltage difference, limit the discharge current of the battery according to the difference between the battery voltage and the current discharge cut-off voltage.

[0064] Specifically, in actual management, according to the different temperatures of the battery, the preset voltage difference is also different, and the voltage difference range is 0.1V to 0.6V. The higher the temperature, the larger the preset voltage difference.

[0065] It should be noted that the preset voltage difference is set according to the actual usage requirements. The purpose of setting the preset voltage difference is to clarify when the battery voltage is close to the discharge cut-off voltage, so as to facilitate the subsequent adjustment of the battery discharge current.

[0066] Limiting the discharge current of a battery according to the difference between the voltage of the battery and the current discharge cut-off voltage includes: when the difference between the voltage of the battery and the current discharge cut-off voltage is less than a preset voltage difference but greater than 0, making the discharge current of the battery decrease as the difference decreases; when the voltage of the battery is equal to the discharge cut-off voltage, issuing a loop cut-off instruction, which is used to cut off the discharge loop of the battery.

[0067] It can be understood that the normal discharge current is given according to the discharge MAP table. The idea here is that when the battery voltage is close to the cut-off voltage, a current coefficient less than 1 is given to reduce the discharge current. The closer the two are, the smaller the current coefficient until it becomes 0.

[0068] Specifically, the normal discharge current of the battery is given according to the cell discharge power map table. Therefore, when the battery voltage is close to the cut-off voltage, the present application sets a current coefficient less than 1 to reduce the discharge current. The closer the voltage of the battery is to the cut-off voltage, the smaller the current coefficient until it becomes 0.

[0069] It can be understood that by adjusting the discharge current of the battery when the SOC of the battery is lower than a preset value and close to the cut-off voltage, the occurrence of battery under-voltage faults is effectively prevented, and the use safety of the device is improved.

[0070] See Figure 3 , the present invention also discloses a battery management system for performing the battery management method provided in the above embodiment. This system includes: a battery state detection module 301, a cut-off voltage adjustment module 302, an SOC correction module 303, and a battery management module 304.

[0071] Among them, the battery state detection module 301 is used to monitor the temperature and voltage of the battery in real time. The cut-off voltage adjustment module 302 is used to adjust the discharge cut-off voltage of the battery according to the temperature of the battery.

[0072] The SOC correction module 303 is used to correct the calculation method of the SOC of the battery when the temperature of the battery is lower than a preset low-temperature judgment threshold. The battery management module 304 is used to limit the discharge current of the battery according to the difference between the voltage of the battery and the current discharge cut-off voltage in response to the current SOC of the battery being lower than a preset value and the difference between the voltage of the battery and the current discharge cut-off voltage being less than a preset voltage difference.

[0073] Further, the SOC correction module includes: a loss coefficient calculation unit for calculating the loss coefficient of the battery according to the temperature of the battery; a discharge loss value calculation unit for calculating the SOC discharge loss value of the battery according to the loss coefficient of the battery; and a correction calculation unit for correcting the battery SOC based on the SOC discharge loss value of the battery.

[0074] Further, the loss coefficient calculation unit is specifically configured to: determine the temperature range corresponding to the temperature of the battery according to the temperature of the battery and a preset temperature range; determine the loss coefficient corresponding to the temperature of the battery according to the temperature range corresponding to the temperature of the battery and preset relationship data, where the relationship data is the relationship data corresponding to the temperature range and the loss coefficient.

[0075] Further, the discharge loss value calculation unit is specifically configured to: calculate the SOC discharge loss value of the battery according to the loss coefficient of the battery, and the formula is: SOC discharge loss value = ∫I 放 *Sxdt 放 / C 额定容量 where, I 放 is the output current value of the battery, t 放 is the duration of discharging the battery with the current magnitude of I 放 , C 额定容量 is the rated capacity of the battery, and Sx is the loss coefficient of the battery.

[0076] Further, the correction calculation unit is specifically configured to: correct the SOC of the battery according to the SOC discharge loss value of the battery, and the formula is: SOC 修正后 =(SOC 常温状态 -(SOC 低温冻结 +SOC 放电损耗值 )) / (100%-(SOC 低温冻结 +SOC 放电损耗值 )); where, SOC 低温冻结 =100%-the capacity retention rate of the battery.

[0077] Further, the battery management module 304 is specifically configured to: when the difference between the voltage of the battery and the current discharge cut-off voltage is less than a preset voltage difference but greater than 0, reduce the discharge current of the battery as the difference decreases; when the voltage of the battery is equal to the discharge cut-off voltage, issue a loop cut-off instruction, and the loop cut-off instruction is used to cut off the discharge loop of the battery.

[0078] Further, the system further includes: an upper limit value module, which is specifically configured to:

[0079] judge the magnitude of the SOC discharge loss value and the upper limit value of the preset SOC discharge loss value; when the SOC discharge loss value exceeds the upper limit value, use the upper limit value as the SOC discharge loss value.

[0080] Further, the system further includes: a charging release module, which is specifically configured to:

[0081] When it is detected that the battery is in the charging condition, the SOC discharge loss value of the battery is released according to the magnitude of the charging current of the battery over time; after the SOC discharge loss value of the battery is completely released, the calculation method of the SOC is adjusted to the normal calculation method, and the calculation method of the SOC of the battery is not corrected under the normal calculation method.

[0082] It should be noted that: when the battery management system provided in the above embodiment manages the battery, only the division of the above functional modules is used for illustration. In practical applications, the above functions can be allocated to different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the battery management device provided in the above embodiment and the embodiment of the battery management method belong to the same concept, and the specific implementation process is detailed in the method embodiment and will not be repeated here.

[0083] An embodiment of the present invention provides an electronic device, which includes: a memory and a processor. The processor is connected to the memory and is configured to execute the above battery management method based on instructions stored in the memory. The number of processors can be one or more, and the processor can be a single-core or multi-core processor. The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of, for example, read-only memory (ROM) or flash memory (flashRAM), and the memory includes at least one storage chip. The memory can be an example of the following computer-readable medium.

[0084] An embodiment of the present invention provides a computer-readable storage medium, on which at least one instruction, at least one program, a code set or an instruction set is stored, and at least one instruction, at least one program, a code set or an instruction set is loaded and executed by a processor to implement the above battery management method. The computer-readable storage medium includes: permanent and non-permanent, removable and non-removable media can be implemented by any method or technology for information storage. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to: phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette tapes, disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information accessible by a computing device.

[0085] The present invention also discloses a computer program product including instructions, which causes the above method to be executed by a computer when the computer program product runs on the computer.

[0086] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects: improving the accuracy of battery SOC estimation; reducing the SOC estimation error at low temperatures through temperature compensation and model correction, and improving the reliability of the battery management system. In addition, it can also prevent dynamic correction at the end of discharge and battery SOC jump: by rapidly decreasing the battery SOC in a low-temperature state, the discharge power and discharge current decrease, and the single-cell voltage increases, which can effectively avoid dynamic correction at the end of discharge, effectively avoid dynamic correction at the end of battery discharge at low temperatures, and make full use of the battery capacity. And through the end-of-discharge protection mechanism, the occurrence of battery undervoltage faults is effectively prevented, and the use safety of the device is improved.

[0087] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A battery management method, characterized in that, It includes the following steps: Real-time monitor the temperature and voltage of the battery; Adjust the discharge cut-off voltage of the battery according to the temperature of the battery; When the temperature of the battery is lower than the preset low-temperature judgment threshold, correct the calculation method of the SOC of the battery; In response to the current SOC of the battery being lower than the preset value and the difference between the voltage of the battery and the current discharge cut-off voltage being less than the preset voltage difference, limit the discharge current of the battery according to the difference between the voltage of the battery and the current discharge cut-off voltage.

2. The battery management method according to claim 1, wherein The limiting of the discharge current of the battery according to the difference between the voltage of the battery and the current discharge cut-off voltage includes: When the difference between the voltage of the battery and the current discharge cut-off voltage is less than the preset voltage difference but greater than 0, make the discharge current of the battery decrease as the difference decreases; When the voltage of the battery is equal to the discharge cut-off voltage, issue a loop cut-off command, and the loop cut-off command is used to cut off the discharge loop of the battery.

3. A battery management method according to claim 1, characterized in that, The correcting of the calculation method of the SOC of the battery when the temperature of the battery is lower than the preset low-temperature judgment threshold includes: Calculate the loss coefficient of the battery according to the temperature of the battery; Calculate the SOC discharge loss value of the battery according to the loss coefficient of the battery; Correct the SOC of the battery based on the SOC discharge loss value of the battery.

4. The battery management method according to claim 3, characterized in that, After calculating the SOC discharge loss value of the battery according to the loss coefficient of the battery, it further includes: Judge the magnitude of the SOC discharge loss value and the upper limit value of the preset SOC discharge loss value; When the SOC discharge loss value exceeds the upper limit value, use the upper limit value as the SOC discharge loss value.

5. The battery management method according to claim 3, wherein The calculating of the loss coefficient of the battery according to the temperature of the battery includes: Judge the temperature range corresponding to the temperature of the battery according to the temperature of the battery and the preset temperature range; Determine the loss coefficient corresponding to the temperature of the battery according to the temperature range corresponding to the temperature of the battery and the preset relationship data, and the relationship data is the relationship data corresponding to the temperature range and the loss coefficient.

6. A battery management method according to claim 3, characterized in that The formula for calculating the SOC discharge loss value of the battery according to the loss coefficient of the battery is: SOC discharge loss value = ∫I 放 *Sxdt 放 / C 额定容量 Wherein, I 放 is the output current value of the battery, and t 放 is the duration of discharging the battery with a current magnitude of I 放 ; C 额定容量 is the rated capacity of the battery, and Sx is the loss coefficient of the battery.

7. A battery management method according to claim 3, characterized in that The formula for correcting the SOC of the battery according to the SOC discharge loss value of the battery is: SOC 修正后 =(SOC 常温状态 -(SOC 低温冻结 +SOC 放电损耗值 )) / (100%-(SOC 低温冻结 +SOC 放电损耗值 )); Among them, SOC 低温冻结 = 100% - Capacity retention rate of the battery.

8. A battery management method according to claim 3, wherein After correcting the SOC of the battery based on the SOC discharge loss value of the battery, the following steps are further included: When it is detected that the battery is in the charging condition, release the SOC discharge loss value of the battery according to the magnitude of the charging current of the battery over time; When the SOC discharge loss value of the battery is completely released, adjust the calculation method of the SOC to the normal calculation method, and the normal calculation method does not correct the calculation method of the SOC of the battery.

9. A battery management system, characterized in that, It includes: A battery state detection module that real-time monitors the temperature and voltage of the battery; A cut-off voltage adjustment module that adjusts the discharge cut-off voltage of the battery according to the temperature of the battery; An SOC correction module that corrects the calculation method of the SOC of the battery when the temperature of the battery is lower than the preset low-temperature judgment threshold; The battery management module, in response to the state of charge (SOC) of the current battery being lower than a preset value and the difference between the voltage of the battery and the current discharge cut-off voltage being less than a preset voltage difference, limits the discharge current of the battery according to the difference between the voltage of the battery and the current discharge cut-off voltage.

10. A computer program product comprising instructions, characterized in that, When the computer program product runs on a computer, the method according to any one of claims 1-8 is executed by the computer.

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