Heat dissipation balance control method and system of lithium battery energy storage system

Abstract

The invention belongs to the technical field of data processing, and provides a heat dissipation balance control method and system for a lithium battery energy storage system, and the method comprises the steps: dividing a lithium battery into a plurality of regions according to the model and thermal characteristics of the lithium battery, obtaining the region voltage of each region through an open-circuit voltage test, and calculating the temperature of each region according to the region voltage; the maximum temperature and the minimum temperature are screened out according to the temperatures of all the areas, and whether a heat dissipation starting threshold value is met or not is judged according to the difference value between the maximum temperature and the minimum temperature; when the heat dissipation starting threshold value is met, the optimal heat dissipation amount is calculated based on a preset algorithm; and the optimal control mode is screened out from the preset control modes according to the heat dissipating capacity, the output power of the draught fan is controlled through the screened control mode to achieve air cooling heat dissipation, and when the difference value of the maximum temperature and the minimum temperature is within a preset threshold value, the draught fan is closed. According to the invention, heat dissipation of the lithium battery energy storage system can be quickly and effectively balanced and controlled.

Description

Technical Field

[0001] The present application belongs to the field of data processing technology, and specifically relates to a heat dissipation balance control method and system for a lithium battery energy storage system. Background Art

[0002] Lithium batteries have many advantages and are therefore widely used in electronic equipment, electric vehicles, rail transportation, aerospace and other fields. However, safety issues caused by lithium batteries have gradually been exposed. Among them, the main safety issue is caused by thermal runaway of lithium battery energy storage systems. When heat is unevenly distributed and cannot be dissipated in time, it will cause battery leakage, deformation, fire, and even explosion.

[0003] At present, a cooling system is usually used to dissipate heat from a lithium battery energy storage system. The cooling system includes an active cooling system and a passive cooling system. The active cooling system uses cheap air or cooling liquid through a fluid conveying device to perform forced convection heat dissipation in the battery stack. However, it is found in practice that the additional fluid conveying device increases the energy consumption of the system, and its cooling effect is easily restricted by the ambient temperature. The passive cooling system mainly uses phase change materials, heat pipe technology, etc., and its disadvantages are that the battery cells may be contaminated by the phase change material, resulting in failure to charge and discharge smoothly, and inconvenient maintenance when a fault occurs.

[0004] In addition, both active cooling and passive cooling systems inevitably increase the weight and volume of the system, and their heat dissipation capabilities have an upper limit, and cannot fundamentally solve the problems of excessive temperature and uneven temperature distribution, especially the serial active cooling system, which artificially increases the unevenness of temperature distribution. Summary of the invention

[0005] The embodiments of the present application provide a heat dissipation balance control method and system for a lithium battery energy storage system to solve the above technical problems.

[0006] A first aspect of an embodiment of the present application provides a heat dissipation balance control method for a lithium battery energy storage system, comprising:

[0007] According to the model and thermal characteristics of the lithium battery, the lithium battery is divided into several areas. The regional voltage of each area is obtained through open circuit voltage test, and the temperature of each area is calculated based on the regional voltage;

[0008] The maximum and minimum temperatures are screened out based on the temperature of each area, and whether the heat dissipation start threshold is met is determined based on the difference between the maximum and minimum temperatures;

[0009] When the heat dissipation start threshold is met, the optimal heat dissipation is calculated based on the preset algorithm;

[0010] The optimal control method is selected from the preset control methods according to the heat dissipation, and the output power of the fan is controlled by the selected control method to achieve air cooling. When the difference between the maximum temperature and the minimum temperature is within the preset threshold, the fan is turned off.

[0011] Furthermore, the lithium battery is divided into several regions according to the model and thermal characteristics of the lithium battery, and the regional voltage of each region is obtained through an open circuit voltage test, and the temperature of each region is calculated according to the regional voltage, wherein:

[0012] The temperature change of each area is measured during the discharge of each 10% state of charge through the open circuit voltage test, and the voltage of each area is calculated.

[0013] Furthermore, the temperature change of each region is measured during the discharge of each 10% state of charge through the open circuit voltage test, and the voltage of each region is calculated, specifically:

[0014] Through the open circuit voltage test, the surface temperature and ambient temperature data of each area are measured during each 10% state of charge discharge, and the voltage of each area is calculated;

[0015] The energy that causes the battery surface temperature to rise is expressed by the following formula:

[0016] Q=mc(T e -T a )

[0017] In the above formula, m is the mass of the battery; T e T is the battery temperature measured at the end of discharge at 10% state of charge; a is the ambient temperature.

[0018] Furthermore, the calculation formula of the regional voltage is as follows:

[0019]

[0020] In the above formula, Q d is the energy of heat exchange; t d is the duration of the discharge process to 10% state of charge; Q is the energy of the battery surface temperature increase.

[0021] Furthermore, the temperature of each of the regions is calculated by volume average heat source, and the calculation formula is as follows:

[0022]

[0023] In the above formula, Q n is the heat generation rate of the region, which can be used to characterize the temperature value, V b is the volume of the battery.

[0024] Further, the method of screening out the maximum temperature and the minimum temperature according to the temperature of each area, and judging whether the heat dissipation start threshold is met according to the difference between the maximum temperature and the minimum temperature, includes the following steps:

[0025] Pair the temperature data of each area in pairs;

[0026] Compare the two data in each pair, put the larger data in the max set and the smaller data in the min set, and then group the temperature data in the max set and the min set in pairs and compare them until the maximum temperature and the minimum temperature are screened out;

[0027] The maximum temperature and the minimum temperature are compared with the preset threshold value. If the maximum temperature and the minimum temperature are greater than the preset threshold value, it indicates that the temperature of the lithium battery energy storage system is unbalanced.

[0028] If it is less than the preset threshold, it means that the temperature of the lithium battery energy storage system is balanced.

[0029] Furthermore, when the heat dissipation start threshold is met, the optimal heat dissipation amount is calculated based on a preset algorithm, including the following steps:

[0030] According to the difference between the maximum temperature value and the minimum temperature value, the heat value that should be emitted is calculated;

[0031] The reference heat value is obtained by dividing the heat value that should be emitted by the average heat value corresponding to the temperature value of each area;

[0032] According to the reference heat value, the state of charge value of each area is calculated;

[0033] The optimal heat dissipation is obtained by combining the charge state and the difference between the maximum temperature and the minimum temperature.

[0034] Furthermore, the optimal control mode is selected from the preset control modes according to the heat dissipation, and the output power of the fan is controlled by the selected control mode to achieve air cooling and heat dissipation. When the difference between the maximum temperature and the minimum temperature is within a preset threshold, the fan is turned off, wherein:

[0035] The preset control modes include constant flow rate control, PID control and LQR control;

[0036] Specifically, the following steps are included:

[0037] According to the range of heat dissipation, it is divided into low, medium and high levels;

[0038] The control method is selected according to the classification, among which the low level adopts constant flow rate control, the middle level adopts PID control, and the high level adopts LQR control.

[0039] Furthermore, it also includes: numbering the air ducts of the lithium battery energy storage system in sequence according to their positions, detecting the temperature of each air duct in real time, and controlling non-adjacent air ducts whose temperatures are lower than a preset value to exhaust and dissipate heat.

[0040] A second aspect of an embodiment of the present application provides a heat dissipation balancing control system for a lithium battery energy storage system, comprising:

[0041] The regional temperature module is used to divide the lithium battery into several regions according to the model and thermal characteristics of the lithium battery, obtain the regional voltage of each region through open circuit voltage test, and calculate the temperature of each region based on the regional voltage;

[0042] A judgment module is used to screen out the maximum temperature and the minimum temperature according to the temperature of each area, and judge whether the heat dissipation start threshold is met according to the difference between the maximum temperature and the minimum temperature;

[0043] A calculation module, used for calculating the optimal heat dissipation based on a preset algorithm when a heat dissipation start threshold is met;

[0044] The heat dissipation module is used to select the optimal control method from the preset control methods according to the heat dissipation, control the output power of the fan through the selected control method to achieve air cooling, and turn off the fan when the difference between the maximum temperature and the minimum temperature is within the preset threshold.

[0045] A third aspect of an embodiment of the present application provides a terminal, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method described in the first aspect when executing the computer program.

[0046] A fourth aspect of an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method described in the first aspect are implemented.

[0047] A fifth aspect of the present application provides a computer program product, which, when executed on a terminal, enables the terminal to execute the steps of the method described in the first aspect.

[0048] As can be seen from the above, the embodiment of the present application divides the lithium battery into several areas according to the model and thermal characteristics of the lithium battery, that is, the entire lithium battery energy storage system is divided into several small areas for refined temperature monitoring. Therefore, the phenomenon of uneven heat can be quickly discovered, and the battery leakage, deformation, fire, and even explosion can be effectively avoided;

[0049] At the same time, the embodiment of the present application performs heat dissipation control according to the regional temperature difference, which can ensure uniform heat dissipation of the entire lithium battery energy storage system, and has a simple algorithm, high reliability and fast calculation speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0051] Figure 1 It is a flow chart of a heat dissipation balance control method of a lithium battery energy storage system provided in an embodiment of the present application;

[0052] Figure 2 It is a structural schematic diagram of a heat dissipation balancing control system of a lithium battery energy storage system provided in an embodiment of the present application;

[0053] Figure 3 It is a structural diagram of a terminal provided in an embodiment of the present application. DETAILED DESCRIPTION

[0054] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0055] It should be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0056] It should also be understood that the terms used in this application specification are only for the purpose of describing specific embodiments and are not intended to limit the application. As used in this application specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0057] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0058] In a specific implementation, the terminal described in the embodiments of the present application includes, but is not limited to, other portable devices such as mobile phones, laptop computers, or tablet computers with touch-sensitive surfaces (e.g., touch screen displays and / or touch pads). It should also be understood that in some embodiments, the device is not a portable communication device, but a desktop computer with a touch-sensitive surface (e.g., touch screen displays and / or touch pads).

[0059] In the following discussion, a terminal including a display and a touch-sensitive surface is described. However, it should be understood that the terminal may include one or more other physical user interface devices such as a physical keyboard, mouse and / or joystick.

[0060] The terminal supports various applications, such as one or more of the following: a drawing application, a presentation application, a word processing application, a website creation application, a disk burning application, a spreadsheet application, a game application, a telephone application, a video conferencing application, an email application, an instant messaging application, a workout support application, a photo management application, a digital camera application, a digital camcorder application, a web browsing application, a digital music player application, and / or a digital video player application.

[0061] Various applications that can be executed on the terminal can use at least one common physical user interface device such as a touch-sensitive surface. One or more functions of the touch-sensitive surface and corresponding information displayed on the terminal can be adjusted and / or changed between applications and / or within corresponding applications. In this way, the common physical architecture of the terminal (e.g., the touch-sensitive surface) can support various applications with user interfaces that are intuitive and transparent to the user.

[0062] It should be understood that the size of the serial numbers of the steps in this embodiment does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

[0063] In order to illustrate the technical solution described in this application, a specific embodiment is provided below for illustration.

[0064] See also Figure 1 , Figure 1 1 is a flow chart of a heat dissipation balance control method for a lithium battery energy storage system provided in an embodiment of the present application. Figure 1 As shown, a heat dissipation balance control method for a lithium battery energy storage system comprises the following steps:

[0065] Step 1: Divide the lithium battery into several areas according to the model and thermal characteristics of the lithium battery, obtain the regional voltage of each area through open circuit voltage test, and calculate the temperature of each area according to the regional voltage;

[0066] Step 2: Filter out the maximum temperature and the minimum temperature according to the temperature of each area, and determine whether the heat dissipation start threshold is met according to the difference between the maximum temperature and the minimum temperature;

[0067] Step 3: When the heat dissipation start threshold is met, the optimal heat dissipation amount is calculated based on a preset algorithm;

[0068] Step 4, select the optimal control method from the preset control methods according to the heat dissipation, control the output power of the fan through the selected control method to achieve air cooling, and turn off the fan when the difference between the maximum temperature and the minimum temperature is within the preset threshold.

[0069] Obviously, the embodiment of the present application divides the lithium battery into several areas according to the model and thermal characteristics of the lithium battery, that is, the entire lithium battery energy storage system is divided into several small areas for refined temperature monitoring. Therefore, the phenomenon of uneven heat can be quickly discovered, and the battery leakage, deformation, fire, and even explosion can be effectively avoided;

[0070] At the same time, heat dissipation control based on regional temperature differences can ensure uniform heat dissipation of the entire lithium battery energy storage system, and the algorithm is simple, highly reliable and fast in calculation.

[0071] In the embodiment of the present application, step 1, according to the model and thermal characteristics of the lithium battery, the lithium battery is divided into several regions, the regional voltage of each region is obtained through an open circuit voltage test, and the temperature of each region is calculated according to the regional voltage, wherein:

[0072] The temperature change of each area can be measured during the discharge of each 10% state of charge through the open circuit voltage test, and the voltage of each area can be calculated;

[0073] In this embodiment, by integrating reversible heat into Joule heat, the voltage of each region is calculated based on the surface temperature and ambient temperature data of each region measured during the discharge of 10% state of charge;

[0074] For example, the energy that causes the battery surface temperature to rise can be expressed by the following formula:

[0075] Q=mc(T e -T a )

[0076] In the above formula, m is the mass of the battery; T e T is the battery temperature measured at the end of discharge at 10% state of charge; a is the ambient temperature;

[0077] The calculation formula of the regional voltage is as follows:

[0078]

[0079] In the above formula, Q d is the energy of heat exchange; t d The duration of the discharge process at 10% state of charge; Q is the energy of the battery surface temperature increase;

[0080] Regional voltage U n is the voltage calculated based on the heat generated, so U n It includes both Joule heat and the entropy change trend with the state of charge. The subscript n represents the area on the battery, and each voltage corresponds to the parameter of the battery heating item in each area;

[0081] By using the volume average heat source, the temperature calculation formula for each area is obtained as follows:

[0082]

[0083] In the above formula, Q n is the heat generation rate of the region, which can be used to characterize the temperature value, V b is the volume of the battery;

[0084] Obviously, the above calculation model can quickly calculate the different values ​​of battery temperature in different areas, and then directly quantify the heat imbalance of the lithium battery energy storage system.

[0085] In the embodiment of the present application, step 2, screening out the maximum temperature and the minimum temperature according to the temperature of each area, and judging whether the heat dissipation start threshold is met according to the difference between the maximum temperature and the minimum temperature, includes the following steps:

[0086] Pair the temperature data of each area in pairs;

[0087] Compare the two data in each pair, put the larger data in the max set and the smaller data in the min set, and then group the temperature data in the max set and the min set in pairs and compare them until the maximum temperature and the minimum temperature are screened out;

[0088] The maximum temperature and the minimum temperature are compared with the preset threshold. If they are greater than the preset threshold, it means that the temperature of the lithium battery energy storage system is unbalanced, that is, the heat dissipation start threshold is met;

[0089] If it is less than the preset threshold, it means that the temperature of the lithium battery energy storage system is balanced, that is, the heat dissipation start threshold is not met.

[0090] Obviously, by pairing and comparing the temperature data of each area, the maximum temperature and the minimum temperature can be quickly screened out. At the same time, since the setting is based on the difference between the maximum temperature and the minimum temperature and is compared with the preset threshold to decide whether to dissipate heat, the temperature balance of the lithium battery energy storage system can be quickly identified and judged.

[0091] In the embodiment of the present application, step 3, when the heat dissipation start threshold is met, the optimal heat dissipation is calculated based on a preset algorithm, including the following steps:

[0092] According to the difference between the maximum temperature value and the minimum temperature value, the heat value that should be emitted is calculated;

[0093] The reference heat value is obtained by dividing the heat value that should be emitted by the average heat value corresponding to the temperature value of each area;

[0094] According to the reference heat value, the state of charge value of each area is calculated;

[0095] The optimal heat dissipation is obtained by combining the charge state and the difference between the maximum temperature and the minimum temperature.

[0096] Obviously, the heat dissipation calculation process of the embodiment of the present application not only takes into account the difference between the maximum temperature and the minimum temperature, but also takes into account the charge state (the current discharge state of the lithium battery affects the heat dissipation). Therefore, the heat dissipation can be made more practical and the reliability can be improved.

[0097] In the embodiment of the present application, step 4 is to select the optimal control mode from the preset control modes according to the heat dissipation, and control the output power of the fan to achieve air cooling through the selected control mode. When the difference between the maximum temperature and the minimum temperature is within the preset threshold, the fan is turned off, wherein:

[0098] The preset control modes include constant flow rate control, PID control and LQR control, etc., which can be set according to needs and are not limited here;

[0099] Specifically, the following steps may be included:

[0100] According to the range of heat dissipation, it is divided into low, medium and high levels;

[0101] The control method is selected according to the classification, among which the low level adopts constant flow rate control, the middle level adopts PID control, and the high level adopts LQR control.

[0102] It can be seen that by adopting different control methods according to different levels of heat dissipation, heat dissipation can be optimized in a graded manner, thereby effectively improving the heat dissipation effect.

[0103] In addition, it should be noted that in the prior art, a lithium battery energy storage system generally includes an energy storage cabinet, a plurality of lithium battery modules, a plurality of cooling fans, and a plurality of air ducts;

[0104] Multiple lithium battery modules are installed in the energy storage cabinet, and multiple heat dissipation fans are installed on one side of the multiple lithium battery modules. The multiple lithium battery modules are usually installed in rows in the energy storage cabinet, and a row of lithium battery modules is installed on one side of each air duct, so that the heat generated by each row of lithium battery modules is transported to the outside of the energy storage cabinet through the air duct, so as to achieve the purpose of heat dissipation and cooling of the lithium battery modules.

[0105] Among them, the fan settings usually include internal fans and external fans. The internal fans are independent fans that come with the lithium battery module, while the external fans are independently installed fans. Regardless of whether the internal fans or external fans are used, the heat is transmitted from the air duct to the outside world, which makes the heat easily affected by the temperature crosstalk between multiple air ducts, especially between adjacent air ducts, resulting in uneven heat dissipation.

[0106] Based on this, in this embodiment, the air ducts of the lithium battery energy storage system are numbered in sequence according to their positions, with adjacent positions having adjacent numbers. The temperature of each air duct is detected in real time, and non-adjacent air ducts with temperatures below a preset value are controlled to exhaust and dissipate heat.

[0107] Obviously, the above setting can effectively avoid the problem of uneven heat dissipation caused by temperature crosstalk between air ducts.

[0108] Based on the same inventive concept, the present application embodiment provides a heat dissipation balance control system for a lithium battery energy storage system, such as Figure 2 As shown, the system includes:

[0109] The regional temperature module 1 is used to divide the lithium battery into several regions according to the model and thermal characteristics of the lithium battery, obtain the regional voltage of each region through open circuit voltage test, and calculate the temperature of each region according to the regional voltage;

[0110] The judgment module 2 is used to screen out the maximum temperature and the minimum temperature according to the temperature of each area, and judge whether the heat dissipation start threshold is met according to the difference between the maximum temperature and the minimum temperature;

[0111] The calculation module 3 is used to calculate the optimal heat dissipation based on a preset algorithm when the heat dissipation start threshold is met;

[0112] The heat dissipation module 4 is used to select the optimal control mode from the preset control modes according to the heat dissipation, and control the output power of the fan to achieve air cooling through the selected control mode. When the difference between the maximum temperature and the minimum temperature is within the preset threshold, the fan is turned off.

[0113] Obviously, the embodiment of the present application divides the lithium battery into several areas according to the model and thermal characteristics of the lithium battery, that is, the entire lithium battery energy storage system is divided into several small areas for refined temperature monitoring. Therefore, the phenomenon of uneven heat can be quickly discovered, and the battery leakage, deformation, fire, and even explosion can be effectively avoided;

[0114] At the same time, heat dissipation control based on regional temperature differences can ensure uniform heat dissipation of the entire lithium battery energy storage system, and the algorithm is simple, highly reliable and fast in calculation.

[0115] Figure 3 is a structural diagram of a terminal provided in an embodiment of the present application. As shown in the figure, the terminal 3 of the embodiment includes: at least one processor 30 ( Figure 3 Only one is shown in the figure), a memory 31, and a computer program 32 stored in the memory 31 and executable on the at least one processor 30, wherein the processor 30 implements the steps of any of the above-mentioned method embodiments when executing the computer program 32.

[0116] The terminal 3 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The terminal 3 may include, but is not limited to, a processor 30 and a memory 31. Those skilled in the art will appreciate that Figure 3 It is only an example of terminal 3 and does not constitute a limitation on terminal 3. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the terminal may also include input and output devices, network access devices, buses, etc.

[0117] The processor 30 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0118] The memory 31 may be an internal storage unit of the terminal 3, such as a hard disk or memory of the terminal 3. The memory 31 may also be an external storage device of the terminal 3, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the terminal 3. Further, the memory 31 may also include both an internal storage unit of the terminal 3 and an external storage device. The memory 31 is used to store the computer program and other programs and data required by the terminal. The memory 31 may also be used to temporarily store data that has been output or is to be output.

[0119] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0120] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0121] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0122] In the embodiments provided in the present application, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0123] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0124] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0125] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0126] The present application implements all or part of the processes in the above-mentioned embodiment method, and may also be implemented through a computer program product. When the computer program product runs on a terminal, the terminal can implement the steps in the above-mentioned method embodiments when executing the computer program product.

[0127] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A heat dissipation balance control method for a lithium battery energy storage system, characterized in that: include: According to the model and thermal characteristics of the lithium battery, the lithium battery is divided into several areas. The regional voltage of each area is obtained through open circuit voltage test, and the temperature of each area is calculated based on the regional voltage; The maximum and minimum temperatures are screened out based on the temperature of each area, and whether the heat dissipation start threshold is met is determined based on the difference between the maximum and minimum temperatures; When the heat dissipation start threshold is met, the optimal heat dissipation is calculated based on the preset algorithm; The optimal control method is selected from the preset control methods according to the heat dissipation, and the output power of the fan is controlled by the selected control method to achieve air cooling. When the difference between the maximum temperature and the minimum temperature is within the preset threshold, the fan is turned off.

2. The method according to claim 1, characterized in that According to the model and thermal characteristics of the lithium battery, the lithium battery is divided into several areas, and the regional voltage of each area is obtained through open circuit voltage testing, and the temperature of each area is calculated according to the regional voltage, wherein: The temperature change of each area is measured during the discharge of each 10% state of charge through the open circuit voltage test, and the voltage of each area is calculated.

3. The method according to claim 1, characterized in that The temperature change of each region is measured during the discharge of each 10% state of charge by the open circuit voltage test, and the voltage of each region is calculated, specifically: Through the open circuit voltage test, the surface temperature and ambient temperature data of each area are measured during each 10% state of charge discharge, and the voltage of each area is calculated; The energy that causes the battery surface temperature to rise is expressed by the following formula: Q=mc(T e -T a ) In the above formula, m is the mass of the battery; T e T is the battery temperature measured at the end of discharge at 10% state of charge; a is the ambient temperature.

4. The method according to claim 3, characterized in that The calculation formula of the regional voltage is as follows: In the above formula, Q d is the energy of heat exchange; t d is the duration of the discharge process to 10% state of charge; Q is the energy of the battery surface temperature increase.

5. The method according to claim 4, characterized in that The temperature of each of the regions is calculated by volume average heat source, and the calculation formula is as follows: In the above formula, Q n is the heat generation rate of the region, which can be used to characterize the temperature value, V b is the volume of the battery.

6. The method according to claim 1, characterized in that The method of screening out the maximum temperature and the minimum temperature according to the temperature of each area, and judging whether the heat dissipation start threshold is met according to the difference between the maximum temperature and the minimum temperature, includes the following steps: Pair the temperature data of each area in pairs; Compare the two data in each pair, put the larger data in the max set and the smaller data in the min set, and then group the temperature data in the max set and the min set in pairs and compare them until the maximum temperature and the minimum temperature are screened out; The maximum temperature and the minimum temperature are compared with the preset threshold value. If the maximum temperature and the minimum temperature are greater than the preset threshold value, it indicates that the temperature of the lithium battery energy storage system is unbalanced. If it is less than the preset threshold, it means that the temperature of the lithium battery energy storage system is balanced.

7. The method according to claim 1, characterized in that When the heat dissipation start threshold is met, the optimal heat dissipation amount is calculated based on a preset algorithm, including the following steps: According to the difference between the maximum temperature value and the minimum temperature value, the heat value that should be emitted is calculated; The reference heat value is obtained by dividing the heat value that should be emitted by the average heat value corresponding to the temperature value of each area; According to the reference heat value, the state of charge value of each area is calculated; The optimal heat dissipation is obtained by combining the charge state and the difference between the maximum temperature and the minimum temperature.

8. The method according to claim 1, characterized in that The optimal control method is selected from the preset control methods according to the heat dissipation, and the output power of the fan is controlled by the selected control method to achieve air cooling and heat dissipation. When the difference between the maximum temperature and the minimum temperature is within the preset threshold, the fan is turned off, wherein: The preset control modes include constant flow rate control, PID control and LQR control; Specifically, the following steps are included: According to the range of heat dissipation, it is divided into low, medium and high levels; The control method is selected according to the classification, among which the low level adopts constant flow rate control, the middle level adopts PID control, and the high level adopts LQR control.

9. The method according to claim 8, characterized in that Also includes: The air ducts of the lithium battery energy storage system are numbered in sequence according to their positions, the temperature of each air duct is detected in real time, and the non-adjacent air ducts with temperatures lower than the preset value are controlled for exhaust and heat dissipation.

10. A heat dissipation balance control system for a lithium battery energy storage system, characterized in that: include: The regional temperature module is used to divide the lithium battery into several regions according to the model and thermal characteristics of the lithium battery, obtain the regional voltage of each region through open circuit voltage test, and calculate the temperature of each region based on the regional voltage; A judgment module is used to screen out the maximum temperature and the minimum temperature according to the temperature of each area, and judge whether the heat dissipation start threshold is met according to the difference between the maximum temperature and the minimum temperature; A calculation module, used for calculating the optimal heat dissipation based on a preset algorithm when a heat dissipation start threshold is met; The heat dissipation module is used to select the optimal control method from the preset control methods according to the heat dissipation, control the output power of the fan through the selected control method to achieve air cooling, and turn off the fan when the difference between the maximum temperature and the minimum temperature is within the preset threshold.

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