Calibration method and device of battery pack, calibration equipment and storage medium

Abstract

The invention provides a battery pack calibration method and device, calibration equipment and a storage medium. The battery pack can be connected with calibration equipment, and the calibration equipment comprises a direct-current load; the method comprises the steps of controlling a direct-current load to communicate with a battery pack; obtaining an electrical parameter of a direct current load, wherein the electrical parameter of the direct current load is an actual electrical parameter of the battery pack; acquiring a first sampling electrical parameter of the battery pack; judging whether the first sampling electrical parameter needs to be calibrated or not; if yes, when the preset calibration coefficient recovers the initial value, obtaining a second sampling electrical parameter of the battery pack; calculating a first calibration coefficient according to the actual electrical parameter and the second sampling electrical parameter; acquiring a third sampling electrical parameter of the battery pack, and calculating a theoretical electrical parameter of the battery pack according to the third sampling electrical parameter and the first calibration coefficient; whether the calibration of the battery pack is successful or not is judged, the battery pack can be automatically calibrated, manual calibration is not needed, labor can be saved, efficiency can be improved, and manual errors and misjudgment are avoided.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to a calibration method, device, calibration equipment and storage medium for a battery pack. Background Art

[0002] The battery pack is an important energy storage product. The battery pack integrates the battery module and the BMS (Battery Management System) module to jointly realize the storage, monitoring and management of electric energy. The battery pack is composed of multiple single cells connected in series and parallel, which is responsible for storing electric energy; while the BMS is responsible for monitoring the status of each single cell in the battery module, such as voltage, current, temperature, etc., as well as performing the balancing, protection, communication and other functions of the battery module to ensure the safe and efficient operation of the battery pack. Calibration is a crucial step before the battery pack leaves the factory. The calibration process is designed to ensure that the performance indicators of the battery pack meet the design requirements, so that it has excellent performance indicators and reliable safety performance, providing solid protection for the user's subsequent use.

[0003] However, in the process of implementing the embodiments of the present application, the inventors of the present application found that in the prior art, calibration of the battery pack requires manual setting of the voltage or current source, checking the actual measurement value of the multimeter, and then manually recording it, and then checking it one by one with the standard value. This is labor-intensive, inefficient, and prone to misjudgment, recording errors or falsification. Summary of the invention

[0004] In view of the above problems, the present application provides a battery pack calibration method, apparatus, calibration device and storage medium, which overcome the above problems or at least partially solve the above problem of requiring human division of labor to calibrate the battery pack.

[0005] According to one aspect of the present application, a calibration method for a battery pack is provided, wherein the battery pack can be connected to a calibration device, wherein the calibration device includes a DC load; the method includes: controlling the DC load to connect to the battery pack; obtaining electrical parameters of the DC load, wherein the electrical parameters of the DC load are actual electrical parameters of the battery pack; obtaining first sampled electrical parameters of the battery pack; determining whether the first sampled electrical parameters need to be calibrated; if so, obtaining second sampled electrical parameters of the battery pack when a preset calibration coefficient is restored to an initial value; calculating a first calibration coefficient based on the actual electrical parameters and the second sampled electrical parameters; obtaining third sampled electrical parameters of the battery pack, and calculating theoretical electrical parameters of the battery pack based on the third sampled electrical parameters and the first calibration coefficient; determining whether the calibration of the battery pack is successful based on the theoretical electrical parameters and the actual electrical parameters.

[0006] In an optional manner, the calibration device also includes a first relay and a first contactor, and the first relay and the first contactor are connected between the battery pack and the DC load. The step of controlling the DC load to connect to the battery pack includes: controlling the first relay to open the first contactor to control the DC load to connect to the battery pack.

[0007] In an optional manner, the step of determining whether the calibration of the battery pack is successful based on the theoretical electrical parameters and the actual electrical parameters includes: calculating a first error of the theoretical electrical parameters relative to the actual electrical parameters; determining whether the first error is within a preset first range; and if so, determining that the calibration is successful.

[0008] In an optional manner, the calibration device also includes a DC power supply, and the method also includes: controlling the DC power supply to connect to the battery pack; setting the output current of the DC power supply; obtaining a first charging current of the battery pack; determining whether the first charging current needs to be calibrated; if so, obtaining a second charging current of the battery pack when the preset calibration coefficient is restored to an initial value; calculating a second calibration coefficient based on the output current and the second charging current; obtaining a third charging current of the battery pack, and calculating a theoretical charging current of the battery pack based on the third charging current and the second calibration coefficient; and determining whether the calibration of the battery pack is successful based on the theoretical charging current and the output current.

[0009] In an optional manner, the step of setting the output current of the DC power supply includes: controlling the DC power supply to output a primary current; and after a preset time, controlling the DC power supply to output the output current, wherein the primary current is smaller than the output current.

[0010] In an optional manner, the calibration device also includes a second relay and a second contactor, and the second relay and the second contactor are connected between the battery pack and the DC power supply. The step of controlling the DC power supply to connect to the battery pack includes: controlling the second relay to open the second contactor to control the DC voltage to connect to the battery pack.

[0011] In an optional manner, the step of determining whether the calibration of the battery pack is successful based on the theoretical charging current and the output current includes: calculating a second error of the theoretical electrical parameter relative to the output current; determining whether the second error is within a preset second range; and if so, determining that the calibration is successful.

[0012] In an optional manner, before the step of controlling the DC load to connect to the battery pack, the method further includes: detecting whether the battery pack is qualified; if so, executing the step of controlling the DC load to connect to the battery pack.

[0013] In an optional manner, the calibration device also includes a thermometer, and the step of detecting whether the battery pack is qualified includes: obtaining the SN code of the battery pack; controlling the battery pack and the calibration device to restore to a ready state; sending an aging instruction to the battery pack; obtaining information after the battery pack executes the aging instruction, the information including a BMS version number, a voltage difference between each single string of cells in the battery pack, a first temperature value of the thermometer, and a second temperature value of the battery pack; checking the BMS version number to determine whether the pressure difference is qualified, and whether the temperature difference between the first temperature value and the second temperature value is qualified; if the BMS version number matches the calibration device, the pressure difference is qualified, and the temperature difference is qualified, then the battery pack is determined to be qualified.

[0014] According to one aspect of an embodiment of the present application, a calibration device for a battery pack is provided, wherein the battery pack can be connected to a calibration device, and the calibration device includes a DC load; the device includes: a control module, used to control the DC load to connect to the battery pack; a first acquisition module, used to acquire electrical parameters of the DC load, wherein the electrical parameters of the DC load are actual electrical parameters of the battery pack; a second acquisition module, used to acquire first sampled electrical parameters of the battery pack; a judgment module, used to judge whether the first sampled electrical parameters need to be calibrated, and if so, execute a third acquisition module; the third acquisition module, used to acquire second sampled electrical parameters of the battery pack when a preset calibration coefficient restores an initial value; a calculation module, used to calculate a first calibration coefficient based on the actual electrical parameters and the second sampled electrical parameters; a fourth acquisition module, used to acquire the third sampled electrical parameters of the battery pack, and calculate the theoretical electrical parameters of the battery pack based on the third sampled electrical parameters and the first calibration coefficient; a calibration module, used to judge whether the calibration of the battery pack is successful based on the theoretical electrical parameters and the actual electrical parameters.

[0015] According to one aspect of an embodiment of the present application, a calibration device is provided, which includes: at least one processor, and a memory, wherein the memory is communicatively connected to the at least one processor, the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method as described above.

[0016] According to one aspect of an embodiment of the present application, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the processor performs the steps of the above method.

[0017] The beneficial effects of the present application include: through the above-mentioned battery pack calibration method, through automated calibration process and automated calibration result judgment, there is no need for manual calibration of the battery pack, which can reduce labor intensity, improve calibration efficiency, and avoid errors and misjudgments that may be caused by manual calibration and calculation, thereby ensuring the accuracy and reliability of the calibration results, and further improving the performance and safety of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0019] Figure 1 is a schematic diagram of a calibration device provided in an embodiment of the present application connected to a battery pack;

[0020] Figure 2 is a schematic diagram of a partial connection battery pack of a calibration device provided in an embodiment of the present application;

[0021] Figure 3 This is another schematic method of connecting the calibration device to the battery pack provided in the embodiment of the present application;

[0022] Figure 4 It is a schematic diagram of the hardware structure of the host computer provided in the embodiment of the present application;

[0023] Figure 5 is a flowchart of a battery pack calibration method provided in an embodiment of the present application;

[0024] Figure 6 is a flowchart of determining whether calibration of a battery pack is successful, provided in an embodiment of the present application;

[0025] Figure 7 : is a flow chart of another calibration method of a battery pack provided in an embodiment of the present application:

[0026] Figure 8 is a schematic diagram of a flow chart of setting the output current of a DC power supply provided in an embodiment of the present application;

[0027] Fig. 9 is a flowchart of another implementation method for determining whether calibration of a battery pack is successful provided in an embodiment of the present application;

[0028] Fig.10 : is a flowchart of another calibration method of the battery pack provided in the embodiment of the present application:

[0029] Fig.11 : is a flow chart of another calibration method of a battery pack provided in an embodiment of the present application:

[0030] Fig.12 This is a schematic diagram of the process of detecting whether a battery pack is qualified provided in an embodiment of the present application:

[0031] Fig.13 It is a schematic diagram of a battery pack calibration device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field belong to the scope of protection of this application.

[0033] In addition, the technical features involved in the embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0034] See also Figure 1 , Figure 1 is a schematic diagram of a calibration device provided in an embodiment of the present application connected to a battery pack, Figure 1 In the embodiment, the calibration device 100 is connected to the battery pack 200 for calibrating the battery pack 200 .

[0035] For the calibration device 100, the calibration device 100 includes a host computer 1, a DC load 2, a first relay 3, a first contactor 4, a DC power supply 5, a second relay 6, a second contactor 7 and a temperature meter 8. The DC load 2, the first relay 3, the DC power supply 5, the second relay 6 and the temperature meter 8 are respectively connected to the host computer 1. The host computer 1 is used to execute the calibration method of the battery pack shown in the following embodiment, and the host computer 1 has a built-in calibration device for the battery pack shown in the following embodiment.

[0036] Please also read Figure 1 and Figure 2 The DC load 2 is used to communicate with the battery pack 200 so that the host computer 1 obtains the electrical parameters of the DC load. The electrical parameters may be the voltage of the DC load or the discharge current of the DC load.

[0037] The first relay 3 and the first contactor 4 are connected between the battery pack 200 and the DC load 2. The host computer 1 is used to control the opening or closing of the first relay 3, and the first relay 3 is used to control the opening or closing of the first contactor 4 to connect the DC load 2 and the battery pack 200. By connecting the battery pack 200 and the DC load 2 through the first relay 3 and the first contactor 4, the current that can pass through the calibration device 100 is larger than when the first contactor 4 is not provided, and the calibration device 100 has a wide range of applicability, that is, the current range of the battery pack 200 that can be calibrated by the calibration device 100 is wide.

[0038] The DC power supply 5 is used to be connected to the battery pack 200 , and the DC power supply 5 is used to charge the battery pack 200 . The output current of the DC power supply 5 can be set according to actual needs.

[0039] The second relay 6 and the second contactor 7 are connected between the battery pack 200 and the DC power supply 5. The host computer 1 is used to control the opening or closing of the second relay 6, and the second relay 6 is used to control the opening or closing of the second contactor 7 to connect the DC power supply 5 and the battery pack 200. By connecting the battery pack 200 and the DC power supply 5 through the second relay 6 and the second contactor 7, the current that can pass through the calibration device 100 is larger than when the second contactor 7 is not provided, and the calibration device 100 has a wide range of application, that is, the calibration device 100 can calibrate a wide range of currents of the battery pack 200.

[0040] The thermometer 8 is used to detect the ambient temperature. The thermometer 8 can be any instrument with a temperature detection function, such as a temperature sensor.

[0041] It is worth noting that, in some embodiments, the calibration device 100 also includes tools for exchanging data and communicating with the battery pack 200, such as an RS-485 (Recommended Standard-485) interface, an RS-232 interface (Recommended Standard-232) and a CAN (Controller Area Network) box, etc.

[0042] For the battery pack 200 described above, the battery pack 200 is a product to be calibrated. Figure 3The battery pack 200 includes a battery module 10 and a BMS module 20. The battery module 10 includes a plurality of battery cells 101, and the plurality of battery cells 101 can be connected in series, in parallel, or in series-parallel (series and then parallel); each series of battery cells is referred to as a single series of battery cells. The battery pack 100 can be specifically configured in a variety of ways, not limited to Figure 1 The situation shown.

[0043] The battery module 10 can be a lithium-ion battery module, which mainly includes consumer battery modules, power battery modules and energy storage battery modules. Among them, the consumer battery module usually requires small size, light weight, high energy density and long cycle life, and is widely used in personal electronic devices such as mobile phones, laptops, tablet computers, digital cameras and portable music players. Among them, the power battery module is mainly used in new energy vehicles, electric bicycles, electric trains and other means of transportation to provide the instantaneous high power output required by the vehicle to support operations such as acceleration and climbing. Among them, the energy storage battery module is mostly used as an energy storage system for renewable energy such as solar energy, wind power, and hydropower, as well as grid peak and frequency regulation, backup power supply, microgrid and other occasions, mainly used for long-term storage and stable release of energy.

[0044] The BMS (Battery Management System) module 20 is responsible for monitoring the operating status of the battery pack 100 and ensuring the safe and reliable operation of the battery pack 100. The BMS module 20 can actually monitor and collect the state parameters of the battery module 10 (including but not limited to the voltage, current, temperature, insulation resistance, etc. of the battery module 10), and perform necessary analysis and calculation on the relevant state parameters to obtain more state evaluation parameters, and realize effective control of the battery module 10 according to a specific protection control strategy to ensure the safe and reliable operation of the entire battery module 10. At the same time, the BMS module 20 can exchange information with the calibration device 100 through its own communication interface and analog / digital input interface to form a linkage control to ensure the safe, reliable and efficient operation of the battery pack 200.

[0045] Embodiment 1

[0046] Before introducing the calibration method of the battery pack in detail, the hardware structure of the host computer 1 provided in the embodiment of the present application is described.

[0047] See also Figure 4 , Figure 4 : is a schematic diagram of the hardware structure of the host computer 1 provided in the embodiment of the present application, which can execute the battery pack calibration method. The host computer 1 includes

[0048] At least one processor 11 and memory 12 (communicatively connected) Figure 4A bus connection and a processor are used as an example). A person skilled in the art can understand that Figure 4 The structure shown is only for illustration and does not limit the structure of the host computer 1. For example, the host computer 1 may also include Figure 4 More or fewer components as shown, or with Figure 4 Different configurations are shown.

[0049] The processor 11 is used to provide computing and control capabilities, and to control the host computer 1 to execute any method provided in the following application embodiments, thereby managing the battery pack 100 accordingly.

[0050] It can be understood that the processor 11 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0051] The memory 12, as a non-transient computer-readable storage medium, can be used to store non-transient software programs, non-transient computer executable programs and modules, such as program instructions / modules corresponding to the various calculation methods in the embodiments of the present application. The processor 11 can implement the various calculation methods in any of the following method embodiments by running the non-transient software programs, instructions and modules stored in the memory 12. The memory 12 may include a high-speed random access memory and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage devices. In some embodiments, the memory 12 may also include a memory remotely arranged relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network and a combination thereof.

[0052] Embodiment 2

[0053] An embodiment of the present application also provides a non-volatile computer-readable storage medium, which stores computer-executable instructions, and the computer-executable instructions are executed by the battery pack to perform various calculation methods in any of the following method embodiments.

[0054] An embodiment of the present application provides a computer program product, including a computing program stored on a non-volatile computer-readable storage medium, wherein the computer program includes program instructions, and when the program instructions are executed by a computer, the computer executes each computing method in any of the following method embodiments.

[0055] Through the description of the above implementation methods, ordinary technicians in this field can clearly understand that each implementation method can be implemented by means of software plus a general hardware platform, and of course it can also be implemented by hardware. Ordinary technicians in this field can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, the storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0056] Embodiment 3

[0057] The following is a discussion of the battery pack calibration method provided in the embodiment of the present application. Figure 5 , Figure 5 : is a flow chart of a battery pack calibration method provided in an embodiment of the present application, the method comprising the following steps:

[0058] Step S1, controlling the DC load to connect to the battery pack.

[0059] The DC load is a device or system that consumes DC power. These loads may include motors, lamps, electronic devices, or any other device that requires DC power to operate. In this step, the DC load is the device that will draw power from the battery pack.

[0060] In some embodiments, the DC load is a DC electronic load, and thus can display an electrical parameter, such as voltage or current.

[0061] In some embodiments, the DC load does not necessarily need to display electrical parameters. The electrical parameters of the DC load can be measured by an external device or an external circuit, so that the calibration device can obtain the electrical parameters of the DC load.

[0062] The connection in step S1 refers to establishing an electrical connection so that current can flow from the battery pack to the DC load. This connection may be achieved through wires, cables, tracks on a circuit board, or other electrical connection methods.

[0063] It is worth noting that, in some embodiments, before controlling the DC load to connect to the battery pack to calibrate the battery pack, the DC load is powered off and then connected to the battery pack. This ensures that the sampled electrical parameters of the battery pack are calibrated before charging and discharging. The sampled electrical parameters of the battery pack are not easily fluctuated due to charging and discharging, thereby improving the accuracy of the calibration.

[0064] It is worth noting that, in some embodiments, the calibration device includes a first relay and a first contactor, the first relay and the first contactor are connected between the battery pack and the DC load, and the step S1, i.e., the step of controlling the DC load to connect to the battery pack, includes: controlling the first relay to turn on the first contactor to control the DC load to connect to the battery pack. Through this method, the battery pack and the DC load are connected through the first relay and the first contactor, and the current that can pass through the calibration device is larger than when the first contactor is not set, and the calibration device has a wide range of applicability, that is, the calibration device can calibrate a wide range of battery pack currents.

[0065] Step S2, obtaining electrical parameters of the DC load, where the electrical parameters of the DC load are actual electrical parameters of the battery pack.

[0066] The electrical parameter may be the current of the DC load, or may be the current of the DC load, that is, the discharge current of the battery pack connected to the DC load.

[0067] As described above, when the DC load is a DC electronic load, it can display electrical parameters, so that the electrical parameters of the DC load can be obtained according to the displayed data. When the DC load does not have the function of displaying electrical parameters, the electrical parameters of the DC load can be obtained through an external device (such as a multimeter, a sensor) or an external circuit (such as a current detection circuit).

[0068] It can be understood that, since the DC load is connected to the battery pack, the electrical parameters of the DC load are consistent with the electrical parameters actually exhibited by the battery pack, that is, the electrical parameters of the DC load are the actual electrical parameters of the battery pack. In other words, when the DC load exhibits electrical parameters such as voltage and discharge current during testing or use, they are actually the electrical parameters exhibited by the battery pack under the same conditions. Based on this principle, by measuring the electrical parameters of the DC load to calibrate the battery pack, it can be ensured that the battery pack can provide accurate and stable power output.

[0069] Step S3, obtaining a first sampled electrical parameter of the battery pack.

[0070] The first sampled electrical parameters are electrical parameters directly measured or calculated from the battery pack, such as voltage, discharge current, etc. These parameters can reflect the working state and performance characteristics of the battery pack.

[0071] It is worth noting that the property of the first sampled electrical parameter is consistent with the property of the electrical parameter of the DC load obtained in the above step. For example, if the electrical parameter of the DC load obtained is voltage, then the first sampled electrical parameter is voltage; if the electrical parameter of the DC load obtained is discharge current, then the first sampled electrical parameter is discharge current.

[0072] It is worth noting that the first sampled electrical parameter of the battery pack can be obtained through the BMS module in the battery pack. The BMS module is an important component of the battery pack, responsible for monitoring various parameters of the battery pack, controlling the charging and discharging process of the battery pack, and communicating with the external system. The BMS module can monitor and record key parameters of the battery pack such as discharge current, discharge current, voltage and discharge temperature with high precision. For example, the BMS module sends a sampling instruction and receives a feedback signal from the battery pack. After these feedback signals are processed, the first sampled electrical parameter can be obtained. Specific sampling methods may include analog sampling, digital sampling, etc.

[0073] In addition, since the calibration device is connected to the battery pack, specifically, the calibration device is connected to the BMS module of the battery pack, that is, the two can exchange information, so that the calibration device can obtain sampling data of the BMS module.

[0074] It is worth noting that the first sampled electrical parameter is a sampled electrical parameter obtained by sampling the battery pack for the first time during a calibration operation of the battery pack.

[0075] Step S4, determining whether the first sampled electrical parameter needs to be calibrated, if so, executing step S5.

[0076] Calibration is a process to ensure the performance of the battery pack. Before the battery pack leaves the factory, the battery pack can be calibrated to ensure its functionality. After the battery pack is moved, the electrical parameters of the battery pack may deviate, so it is also calibrated. In addition, due to factors such as equipment aging and environmental changes (such as temperature and humidity), the performance of the battery pack may be impaired. Therefore, regular or as needed calibration is an important part of maintaining the normal use of the battery pack.

[0077] In some embodiments, after obtaining the electrical parameters of the DC load, that is, the actual electrical parameters of the battery pack and the first sampled electrical parameters of the battery pack, the specific implementation method of determining whether the first sampled electrical parameters need to be calibrated may be: obtaining the deviation of the first sampled electrical parameters relative to the actual electrical parameters; determining whether the deviation is less than a preset threshold; if the deviation is less than the preset threshold, determining that the first sampled electrical parameters do not need to be calibrated; if the deviation is greater than or equal to the preset threshold, determining that the first sampled electrical parameters need to be calibrated.

[0078] It is worth noting that, in some embodiments, the calibration means making the sampled electrical parameters of the battery pack consistent with the electrical parameters of the DC load (ie, the actual electrical parameters of the battery pack) or having only a slight difference, such as a difference of 0.2%.

[0079] Step S5, when the preset calibration coefficient is restored to an initial value, obtaining a second sampled electrical parameter of the battery pack.

[0080] The preset calibration coefficient is a preset parameter, and the preset calibration coefficient can be reasonably set according to actual needs. In some embodiments, the preset calibration coefficient is 10000.

[0081] The second sampled electrical parameter is a sampled electrical parameter obtained by sampling the battery pack at a specific time point or state when a preset calibration coefficient restores an initial value, or it may be a sampled electrical parameter obtained by sampling the battery pack for the second time during a calibration operation of the battery pack.

[0082] It is worth noting that the preset calibration coefficient is used to correct the sampled electrical parameters to eliminate errors caused by sensors, circuits or environmental factors. When the preset calibration coefficient is changed or adjusted, it will affect the accuracy of the sampled electrical parameters. In order to ensure the accuracy of subsequent analysis, evaluation and calibration, it is necessary to reacquire the electrical parameters of the battery pack when the preset calibration coefficient is restored to its initial value. Doing so can eliminate any deviations introduced by changes in the preset calibration coefficient, so that the second sampled electrical parameters obtained can truly reflect the actual state of the battery pack, and provide reliable data support for the subsequent calibration of the battery pack.

[0083] Step S6, calculating a first calibration coefficient according to the actual electrical parameter and the second sampled electrical parameter.

[0084] There are many methods for calculating the first calibration coefficient. In some embodiments, the following formula may be used to calculate the first calibration coefficient:

[0085] k1=(yb)×10000 / x

[0086] Wherein, k1 is the first calibration coefficient, y is the electrical parameter of the DC load, that is, the actual electrical parameter of the battery pack, and x is the second sampled electrical parameter;

[0087] Wherein, b is a calibration deviation value, and the value of b can be 0.

[0088] Step S7, obtaining a third sampled electrical parameter of the battery pack, and calculating a theoretical electrical parameter of the battery pack according to the third sampled electrical parameter and the first calibration coefficient.

[0089] The third sampled electrical parameter is a sampled electrical parameter obtained by sampling the battery pack for the third time during a calibration operation of the battery pack. After obtaining the third sampled electrical parameter and the first calibration coefficient, they can be substituted into the above formula for calculating the first calibration coefficient to obtain the theoretical electrical parameter of the battery pack, which is the data after the battery pack is calibrated.

[0090] Step S8: judging whether the calibration of the battery pack is successful according to the theoretical electrical parameters and the actual electrical parameters.

[0091] After obtaining the theoretical electrical parameters and the actual electrical parameters, it can be further determined whether the calibration of the battery pack is successful. In some embodiments, successful calibration means that the electrical parameters of the battery pack after calibration are consistent with the electrical parameters of the DC load (i.e., the actual electrical parameters of the battery pack) or have only a slight difference, such as a difference of 0.2%. That is, successful calibration means that the theoretical electrical parameters are consistent with the actual electrical parameters or have only a slight difference between the two.

[0092] In some embodiments, see Figure 6 , the implementation method of determining whether the calibration of the battery pack is successful may be:

[0093] Step S81, calculating a first error of the theoretical electrical parameter relative to the actual electrical parameter.

[0094] The first error may be a difference between the theoretical electrical parameter and the actual electrical parameter, or the first error may be a ratio of the difference between the theoretical electrical parameter and the actual electrical parameter to the actual electrical parameter.

[0095] Step S82, determining whether the first error is within a preset first range, if so, executing step S83, if not, executing step S84.

[0096] When the first error is the difference between the theoretical electrical parameter and the actual electrical parameter, the preset first range may be data reasonably set according to the capacity of the battery pack. For example, if the electrical parameter is voltage, the preset first range may be ±0.2V.

[0097] When the first error is a ratio of a difference between the theoretical electrical parameter and the actual electrical parameter to the actual electrical parameter, the preset first range may be ±0.2%.

[0098] Step S83, determining whether the calibration is successful.

[0099] It is worth noting that, in some embodiments, determining whether the calibration is successful in step S83 is merely determining whether the electrical parameters of the battery pack are successful, such as voltage and discharge current. At this time, calibration of the charging current of the battery pack may be further performed as described in the following fourth embodiment.

[0100] Step S84, determining that the calibration is unsuccessful.

[0101] It is worth noting that, in some embodiments, if it is determined that the calibration is unsuccessful, that is, the calibration of the battery pack is unsuccessful, the operation of calibrating the battery pack may be performed again.

[0102] In an embodiment of the present application, the battery pack is connected by controlling the DC load; the electrical parameters of the DC load are obtained, and the electrical parameters of the DC load are the actual electrical parameters of the battery pack; the first sampled electrical parameters of the battery pack are obtained; it is determined whether the first sampled electrical parameters need to be calibrated; if so, when the preset calibration coefficient is restored to the initial value, the second sampled electrical parameters of the battery pack are obtained; the first calibration coefficient is calculated according to the actual electrical parameters and the second sampled electrical parameters; the third sampled electrical parameters of the battery pack are obtained, and the theoretical electrical parameters of the battery pack are calculated according to the third sampled electrical parameters and the first calibration coefficient; and it is determined whether the calibration of the battery pack is successful according to the theoretical electrical parameters and the actual electrical parameters. Then, through the automated calibration process and the automated calibration result judgment, there is no need to manually calibrate the battery pack, which can reduce labor intensity, improve calibration efficiency, and avoid errors and misjudgments that may be caused by manual calibration and calculation, thereby ensuring the accuracy and reliability of the calibration results, and further improving the performance and safety of the battery pack.

[0103] Embodiment 4

[0104] Next, another calibration method of the battery pack provided in the embodiment of the present application is discussed. Figure 7 , Figure 7 is a flow chart of another calibration method of a battery pack provided in an embodiment of the present application, the method comprising the following steps:

[0105] Step S10, controlling the DC power supply to connect to the battery pack.

[0106] A DC power supply is a device or component that can stably output DC power. Its characteristics are that the voltage and current generated are constant and do not change over time, so it is also called constant current or steady DC power. The DC power supply plays the role of maintaining a constant voltage and current in the circuit, and is necessary for the normal operation of many electronic devices and systems.

[0107] The working principle of DC power supply is based on the rectification process, which converts the input AC signal into a pulse signal with only positive half cycle (or negative half cycle), and then converts these pulse signals into a stable DC signal through a filtering circuit. The rectification process is mainly composed of components such as diodes, transformers and filter capacitors.

[0108] In step S10, controlling the DC power supply to connect to the battery pack means connecting the output of the DC power supply to the battery pack to provide DC power to the battery pack.

[0109] In some embodiments, the output current of the DC power supply can be set to different values ​​according to actual needs, which can be achieved in a variety of ways. Specifically, for example, it can be achieved by a voltage stabilizer. The voltage stabilizer can stabilize the input voltage to a set value, thereby indirectly controlling the output current to the set value. Even if the input voltage fluctuates, the voltage stabilizer can keep the output voltage constant to ensure the stability of the output current. For example, by

[0110] PWM (Pulse Width Modulation) Control: PWM (Pulse Width Modulation) technology changes the average voltage and current of the output signal by adjusting the duty cycle. The higher the duty cycle, the greater the average voltage and current; the lower the duty cycle, the smaller the average voltage and current. This technology can also accurately control the current of the output setting.

[0111] It is worth noting that, in some embodiments, the calibration device further includes a second relay and a second contactor, the second relay and the second contactor are connected between the battery pack and the DC power supply, and the step of controlling the DC power supply to connect to the battery pack includes: controlling the second relay to turn on the second contactor to control the DC voltage to connect to the battery pack. Through this method, the battery pack is connected to the DC power supply in the calibration device through the second relay and the second contactor, and the current that can pass through the calibration device is larger than when the second contactor is not provided, and the calibration device has a wide range of applicability, that is, the calibration device can calibrate a wide range of battery pack currents.

[0112] Step S20, setting the output current of the DC power supply.

[0113] It can be understood that, since the DC power supply is connected to the battery pack, the output current of the DC power supply is consistent with the actual charging current of the battery pack, that is, the output current of the DC power supply is the actual charging current of the battery pack. In other words, when the DC power supply shows a charging current during testing or use, it is actually the output current of the battery pack under the same conditions. Based on this principle, by setting the output current of the DC power supply to calibrate the battery pack, the stable operation of the battery pack in the charging state can be ensured.

[0114] In some embodiments, see Figure 8 Step S20, i.e., the step of setting the output current of the DC power supply, comprises:

[0115] Step S201, controlling the DC power supply to output a primary current.

[0116] Step S202: after a preset time, control the DC power supply to output the output current, and the primary current is smaller than the output current.

[0117] It is worth noting that during the battery pack calibration process, directly starting the DC power supply and setting a high current for charging will often trigger the power supply protection mechanism. This is because the battery pack may not be able to immediately withstand such a high current impact in the initial state, which will trigger the power supply safety protection action and interrupt the charging process. This not only affects the efficiency of the calibration, but may also cause unnecessary damage to the battery pack.

[0118] In order to overcome this problem, the embodiment of the present application adopts a staged charging strategy. First, the charging process is started by setting a smaller primary current (i.e., small current). This step is intended to allow the battery pack to gradually enter the charging state and reduce the stress caused by the sudden change of current. As the internal state of the battery pack stabilizes, the output current is gradually adjusted to the required output current (high current) level by precisely controlling the DC power supply.

[0119] This staged charging method not only effectively avoids the DC power protection situation, but also ensures that the battery pack can maintain a stable charging state throughout the calibration process. It improves the smoothness of calibration, reduces calibration errors caused by charging interruptions, and also extends the service life of the battery pack.

[0120] In addition, for different types of battery packs, the primary current and final output current need to be flexibly adjusted according to their specific charging characteristics and requirements to achieve the best calibration effect.

[0121] Step S30, obtaining a first charging current of the battery pack.

[0122] The first charging current is charging current data directly measured or calculated from the battery pack. The specific method for obtaining the first charging current of the battery pack can refer to the method for obtaining the first sampled electrical parameter of the battery pack in Example 3, which will not be repeated here.

[0123] It is worth noting that the first charging current is the charging current obtained by sampling the battery pack for the first time during a calibration operation of the battery pack.

[0124] Step S40, determining whether the first charging current needs to be calibrated, if so, executing step S50.

[0125] The method of determining whether the first charging current needs to be calibrated may also refer to the method of determining whether the first sampled electrical parameter needs to be calibrated in the above-mentioned embodiment 3, which will not be described in detail here.

[0126] Step S50, when the preset calibration coefficient is restored to an initial value, obtaining a second charging current of the battery pack.

[0127] The preset calibration coefficient in step S50, as well as the implementation method and beneficial effects of obtaining the second charging current of the battery pack can also refer to the relevant statement in Example 3 on "obtaining the second sampled electrical parameter of the battery pack when the preset calibration coefficient is restored to the initial value", which will not be repeated here.

[0128] Step S60, calculating a second calibration coefficient according to the output current and the second charging current.

[0129] The specific implementation of step S60 may refer to the related description of calculating the first calibration coefficient in the third embodiment, which will not be repeated here.

[0130] It is worth noting that the second charging current is the charging current obtained by sampling the battery pack for the second time during a calibration operation of the battery pack.

[0131] Step S70, obtaining a third charging current of the battery pack, and calculating a theoretical charging current of the battery pack according to the third charging current and the second calibration coefficient.

[0132] For the specific implementation of step S70, reference may be made to the relevant description of calculating the theoretical electrical parameters of the battery pack in the third embodiment, which will not be repeated here.

[0133] It is worth noting that the third charging current is the charging current obtained by sampling the battery pack for the third time during a calibration operation of the battery pack.

[0134] Step S80: determining whether the calibration of the battery pack is successful according to the theoretical charging current and the output current.

[0135] After obtaining the theoretical charging current and the output current, it can be further determined whether the calibration of the battery pack is successful. In some embodiments, successful calibration means that the charging current of the battery pack after calibration is consistent with the output current of the DC power supply or has only a slight difference, such as a difference of 0.2%. That is, successful calibration means that the theoretical charging current is consistent with the output current or has only a slight difference.

[0136] In some embodiments, see Fig. 9 , the implementation method of determining whether the calibration of the battery pack is successful may be:

[0137] Step S801, calculating a second error of the theoretical charging current relative to the output current.

[0138] The second error may be a difference between the theoretical charging current and the output current, or a ratio of the difference between the theoretical charging current and the output current to the output current.

[0139] Step S802, determining whether the second error is within a preset second range, if so, executing step S803, if not, executing step S804.

[0140] When the second error is the difference between the theoretical charging current and the output current, the preset second range may be data reasonably set according to the capacity of the battery pack, for example, the preset second range may be ±0.2A.

[0141] When the second error is a ratio of a difference between the theoretical charging current and the output current to the output current, the preset second range may be ±0.2%.

[0142] Step S803: determine whether the calibration is successful.

[0143] Step S804: determine that the calibration is unsuccessful.

[0144] It is worth noting that, in some embodiments, if it is determined that the calibration is unsuccessful, that is, the calibration of the battery pack is unsuccessful, the operation of calibrating the battery pack may be performed again.

[0145] In an embodiment of the present application, the DC power supply is controlled to connect to the battery pack; the output current of the DC power supply is set; the first charging current of the battery pack is obtained; it is determined whether the first charging current needs to be calibrated; if so, when the preset calibration coefficient is restored to an initial value, the second charging current of the battery pack is obtained; the second calibration coefficient is calculated based on the output current and the second charging current; the third charging current of the battery pack is obtained, and the theoretical charging current of the battery pack is calculated based on the third charging current and the second calibration coefficient; and whether the calibration of the battery pack is successful is determined based on the theoretical charging current and the output current. Then, an automated calibration process and result evaluation is used, and there is no need for manual intervention in the charging current calibration of the battery pack, which can significantly reduce labor intensity, improve calibration efficiency, and effectively avoid errors and misjudgments that may occur in manual calibration and calculation, thereby ensuring the accuracy and reliability of the calibration results, and ultimately improving the performance and safety of the battery pack.

[0146] Embodiment 5

[0147] See also Fig.10 , Fig.10 : is a flow chart of another calibration method of a battery pack provided in an embodiment of the present application. In addition to the above steps S1 to S8, the method further includes the following steps:

[0148] Step S1', detecting whether the battery pack is qualified, if so, executing step S1, ie the step of controlling the DC load to connect to the battery pack.

[0149] It is worth noting that, in some embodiments, see Fig.11 , Fig.11 : is a flowchart of another calibration method of a battery pack provided in an embodiment of the present application. In addition to the above steps S10 to S80, the method further includes the following steps:

[0150] Step S10', detecting whether the battery pack is qualified, if so, executing step S10, ie the step of controlling the DC power supply to connect to the battery pack.

[0151] It is worth noting that, in some embodiments, see Fig.12 The step of detecting whether the battery pack is qualified comprises:

[0152] Step S11, obtaining the SN code of the battery pack.

[0153] The SN code (Serial Number) is a unique identification code of the battery pack and is used to track and manage the information of the battery pack.

[0154] One implementation of obtaining the SN code of the battery pack is to obtain the information after the user scans the battery pack. Alternatively, in some embodiments, the SN code of the battery pack is written into the BMS module of the battery pack, and when the battery pack is calibrated, the calibration device in communication with the battery pack obtains the SN code of the battery pack.

[0155] Step S12, controlling the battery pack and the calibration device to return to a ready state.

[0156] Before starting the test, you need to ensure that the battery pack and all related calibration equipment are in a ready state to avoid abnormal status of the calibration equipment or battery pack due to non-calibration factors, which may lead to calibration failure.

[0157] It is worth noting that, in some embodiments, before step S12, it is also determined based on the SN code whether the protocol information of the battery pack exists in the BMS module. If so, step S12 is executed; if not, the protocol information can be obtained from the server.

[0158] Specifically, after obtaining the SN code of the battery pack, the model of the battery pack is obtained according to the SN code, and it is determined whether the model of the battery pack exists in the BMS module. If so, step S12 is executed; if not, the protocol information can be obtained from the server.

[0159] Step S13, sending an aging instruction to the battery pack.

[0160] Aging instructions are used to simulate the working conditions of a battery pack under long-term use or extreme conditions to test its performance and stability. If the battery pack can successfully respond to and execute the aging instructions, and the performance after executing the aging instructions meets the preset standards, it will be judged as a qualified product.

[0161] It is worth noting that, after receiving the aging instruction, the battery pack will perform an aging test on the battery pack.

[0162] Step S14, obtaining information of the battery pack after executing the aging instruction, the information including the BMS version number, the voltage difference of each single string of cells in the battery pack, the first temperature value of the thermometer and the second temperature value of the battery pack.

[0163] The BMS version number is key information for identifying the BMS software version. It reflects the functional characteristics of the BMS, the vulnerabilities fixed, and the new functions added. By checking the BMS version number, it can be ensured that the BMS software used is compatible with the calibration equipment, which is the prerequisite for subsequent accurate calibration of the battery pack.

[0164] The first temperature value detected by the thermometer is the ambient temperature, and the second temperature value of the battery pack is the temperature of the battery pack when executing the aging instruction. The first temperature value of the thermometer and the second temperature value of the battery pack can be used to determine whether the battery pack has an abnormal condition.

[0165] Step S15, checking the BMS version number, determining whether the pressure difference is qualified, and determining whether the temperature difference between the first temperature value and the second temperature value is qualified.

[0166] The information obtained after the battery pack executes the aging instruction is judged, and the BMS version number can be checked respectively to determine whether the pressure difference is qualified and whether the temperature difference between the first temperature value and the second temperature value is qualified. If the BMS version number matches the calibration device, the pressure difference is qualified, and the temperature difference is qualified, then the battery pack can be determined to be qualified.

[0167] The method of judging whether the pressure difference is qualified is to judge whether the pressure difference meets a preset pressure difference qualified range, and if so, the pressure difference is judged to be qualified.

[0168] The method of judging whether the temperature difference is qualified is to judge whether the temperature difference meets a preset qualified temperature range. If so, the temperature difference is judged to be qualified.

[0169] Step S16: If the BMS version number matches the calibration device, the pressure difference is qualified, and the temperature difference is qualified, then the battery pack is determined to be qualified.

[0170] If the BMS version number matches the calibration device, it means that the calibration device can calibrate the battery pack. If the pressure difference is qualified and the temperature difference is qualified, it means that the battery pack has shown good performance and stability in the above aging test, and the battery pack can be calibrated safely.

[0171] In the embodiment of the present application, the electrical parameters or charging current of the battery pack are calibrated only after the battery pack is detected to be qualified, thereby avoiding calibration failure or inaccuracy caused by an unqualified battery pack. In addition, the electrical parameters or charging current of the battery pack are calibrated only when the battery pack is qualified, thereby improving the efficiency of calibrating the battery pack.

[0172] Embodiment 6

[0173] The following is a discussion of the battery pack calibration device provided in the embodiment of the present application. Fig.13 , Fig.13: It is a schematic diagram of a battery pack calibration device provided in an embodiment of the present application, wherein the battery pack calibration device D1 includes a control module D11, which is used to control the DC load to connect to the battery pack; a first acquisition module D12, which is used to acquire the electrical parameters of the DC load, wherein the electrical parameters of the DC load are the actual electrical parameters of the battery pack; a second acquisition module D13, which is used to acquire the first sampled electrical parameters of the battery pack; a judgment module D14, which is used to judge whether the first sampled electrical parameters need to be calibrated, and if so, execute the third acquisition module D15; the third acquisition module D15, which is used to acquire the second sampled electrical parameters of the battery pack when the preset calibration coefficient restores the initial value; a calculation module D16, which is used to calculate the first calibration coefficient according to the actual electrical parameters and the second sampled electrical parameters; a fourth acquisition module D17, which is used to acquire the third sampled electrical parameters of the battery pack, and calculate the theoretical electrical parameters of the battery pack according to the third sampled electrical parameters and the first calibration coefficient; a calibration module D18, which is used to judge whether the calibration of the battery pack is successful according to the theoretical electrical parameters and the actual electrical parameters.

[0174] In some embodiments, the calibration device also includes a first relay and a first contactor, which are connected between the battery pack and the DC load, and the control module D1 is specifically used to control the first relay to open the first contactor to control the DC load to connect to the battery pack.

[0175] In some embodiments, the calibration module D18 includes: a calculation unit D181, used to calculate the first error of the theoretical electrical parameter relative to the actual electrical parameter; a judgment unit D182, used to judge whether the first error is within a preset first range, and if so, enter the judgment unit D183; the judgment unit D183 is used to judge whether the calibration is successful.

[0176] In some embodiments, the calibration device D1 of the battery pack also includes a control part D101, which is used to control the DC power supply to connect to the battery pack; a setting part D102, which is used to set the output current of the DC power supply; a first acquisition part D103, which is used to acquire a first charging current of the battery pack; a judgment part D104, which is used to judge whether it is necessary to calibrate the first charging current, and if so, execute the second acquisition part D105; the second acquisition part D105, which is used to acquire the second charging current of the battery pack when the preset calibration coefficient is restored to an initial value; a calculation part D106, which is used to calculate a second calibration coefficient according to the output current and the second charging current; a third acquisition part D107, which is used to acquire a third charging current of the battery pack, and calculate a theoretical charging current of the battery pack according to the third charging current and the second calibration coefficient; a calibration part D108, which is used to judge whether the calibration of the battery pack is successful according to the theoretical charging current and the output current.

[0177] In some embodiments, the setting part D102 includes a first control unit D121 for controlling the DC power supply to output a primary current; a second control unit D122 for controlling the DC power supply to output the output current after a preset time, and the primary current is less than the output current.

[0178] In some embodiments, the calibration device also includes a second relay and a second contactor, which are connected between the battery pack and the DC power supply. The control part D101 is specifically used to control the second relay to open the second contactor to control the DC voltage to connect to the battery pack.

[0179] In some embodiments, the calibration part D108 includes a calculation unit D1081, which is used to calculate the second error of the theoretical electrical parameter relative to the output current; a judgment unit D1082, which is used to judge whether the second error is within a preset second range, and if so, enters the judgment unit D1083; the judgment unit D1083 is used to judge whether the calibration is successful.

[0180] In some embodiments, the battery pack calibration device D1 further includes a detection module D19 for detecting whether the battery pack is qualified. If so, the battery pack enters the control module D11 or the control part D101.

[0181] In some embodiments, the detection module D19 is specifically used to obtain the SN code of the battery pack; control the battery pack and the calibration device to return to a ready state; send an aging instruction to the battery pack; obtain information after the battery pack executes the aging instruction, the information including the BMS version number, the voltage difference of each single string of cells in the battery pack, the first temperature value of the thermometer and the second temperature value of the battery pack; determine whether the BMS version number matches the SN code, determine whether the pressure difference is qualified, and determine whether the temperature difference between the first temperature value and the second temperature value is qualified; if the BMS version number matches the SN code, the pressure difference is qualified, and the temperature difference is qualified, then the battery pack is determined to be qualified.

[0182] In the embodiment of the present application, the DC load is controlled to be connected to the battery pack through the control module D11; the electrical parameters of the DC load are obtained through the first acquisition module D12, and the electrical parameters of the DC load are the actual electrical parameters of the battery pack; the first sampled electrical parameters of the battery pack are obtained through the second acquisition module D13; the judgment module D14 determines whether the first sampled electrical parameters need to be calibrated, and if so, the third acquisition module D15 is executed; the second sampled electrical parameters of the battery pack are obtained through the third acquisition module D15 when the preset calibration coefficient is restored to the initial value; the calculation module D16 calculates the actual electrical parameters and the second sampled electrical parameters according to the actual electrical parameters. number, calculate the first calibration coefficient; obtain the third sampled electrical parameter of the battery pack through the fourth acquisition module D17, and calculate the theoretical electrical parameter of the battery pack according to the third sampled electrical parameter and the first calibration coefficient; determine whether the calibration of the battery pack is successful according to the theoretical electrical parameter and the actual electrical parameter through the calibration module D18. Then, through the automated calibration process and the automated calibration result judgment, there is no need to manually calibrate the battery pack, which can reduce labor intensity, improve calibration efficiency, and avoid errors and misjudgments that may be caused by manual calibration and calculation, thereby ensuring the accuracy and reliability of the calibration result, and further improving the performance and safety of the battery pack.

[0183] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Under the concept of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes in different aspects of the present application as above, which are not provided in detail for the sake of simplicity. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery pack calibration method, characterized in that: The battery pack can be connected to a calibration device, and the calibration device includes a DC load; The method comprises: Controlling the DC load to connect to the battery pack; Acquiring electrical parameters of the DC load, where the electrical parameters of the DC load are actual electrical parameters of the battery pack; Acquiring a first sampled electrical parameter of the battery pack; Determining whether the first sampled electrical parameter needs to be calibrated; If yes, obtaining a second sampled electrical parameter of the battery pack when the preset calibration coefficient is restored to an initial value; Calculating a first calibration coefficient according to the actual electrical parameter and the second sampled electrical parameter; Acquiring a third sampled electrical parameter of the battery pack, and calculating a theoretical electrical parameter of the battery pack according to the third sampled electrical parameter and the first calibration coefficient; Whether calibration of the battery pack is successful is determined according to the theoretical electrical parameter and the actual electrical parameter.

2. The method according to claim 1, characterized in that: The calibration device further includes a first relay and a first contactor, wherein the first relay and the first contactor are connected between the battery pack and the DC load, and the step of controlling the DC load to connect to the battery pack includes: The first relay is controlled to open the first contactor to control the DC load to connect to the battery pack.

3. The method according to claim 1, characterized in that The step of judging whether the calibration of the battery pack is successful according to the theoretical electrical parameters and the actual electrical parameters includes: Calculating a first error of the theoretical electrical parameter relative to the actual electrical parameter; Determining whether the first error is within a preset first range; If yes, the calibration is deemed successful.

4. The method according to any one of claims 1 to 3, characterized in that: The calibration device also includes a DC power supply, and the method further includes: Controlling the DC power supply to connect to the battery pack; Setting the output current of the DC power supply; Acquiring a first charging current of the battery pack; Determining whether the first charging current needs to be calibrated; If yes, obtaining a second charging current of the battery pack when the preset calibration coefficient is restored to an initial value; Calculating a second calibration coefficient according to the output current and the second charging current; Acquire a third charging current of the battery pack, and calculate a theoretical charging current of the battery pack according to the third charging current and the second calibration coefficient; Whether calibration of the battery pack is successful is determined according to the theoretical charging current and the output current.

5. The method according to claim 4, characterized in that The step of setting the output current of the DC power supply comprises: Controlling the DC power supply to output a primary current; After a preset time, the DC power supply is controlled to output the output current, and the primary current is smaller than the output current.

6. The method according to claim 5, characterized in that The calibration device further includes a second relay and a second contactor, wherein the second relay and the second contactor are connected between the battery pack and the DC power supply, and the step of controlling the DC power supply to connect to the battery pack includes: The second relay is controlled to open the second contactor to control the DC voltage to connect to the battery pack.

7. The method according to claim 6, characterized in that The step of judging whether the calibration of the battery pack is successful according to the theoretical charging current and the output current includes: Calculating a second error of the theoretical electrical parameter relative to the output current; Determining whether the second error is within a preset second range; If yes, the calibration is deemed successful.

8. The method according to claim 1, characterized in that Before the step of controlling the DC load to be connected to the battery pack, the method further includes: Detecting whether the battery pack is qualified; If yes, the step of controlling the DC load to connect to the battery pack is performed.

9. The method according to claim 8, characterized in that The calibration device further includes a temperature meter, and the step of detecting whether the battery pack is qualified includes: Obtaining the SN code of the battery pack; Controlling the battery pack and the calibration device to return to a ready state; Sending an aging instruction to the battery pack; Obtaining information after the battery pack executes the aging instruction, the information including a BMS version number, a voltage difference of each single string of cells in the battery pack, a first temperature value of the thermometer, and a second temperature value of the battery pack; Checking the BMS version number, determining whether the pressure difference is qualified, and determining whether the temperature difference between the first temperature value and the second temperature value is qualified; If the BMS version number matches the calibration device, the pressure difference is qualified, and the temperature difference is qualified, then the battery pack is determined to be qualified.

10. A battery pack calibration device, characterized in that: The battery pack can be connected to a calibration device, and the calibration device includes a DC load; The device comprises: A control module, used for controlling the DC load to be connected to the battery pack; A first acquisition module, used to acquire electrical parameters of the DC load, where the electrical parameters of the DC load are actual electrical parameters of the battery pack; A second acquisition module, used to acquire a first sampled electrical parameter of the battery pack; A judging module, used for judging whether the first sampled electrical parameter needs to be calibrated, and if so, executing a third obtaining module; A third acquisition module, used for acquiring a second sampled electrical parameter of the battery pack when the preset calibration coefficient is restored to an initial value; A calculation module, configured to calculate a first calibration coefficient according to the actual electrical parameter and the second sampled electrical parameter; a fourth acquisition module, configured to acquire a third sampled electrical parameter of the battery pack, and calculate a theoretical electrical parameter of the battery pack according to the third sampled electrical parameter and the first calibration coefficient; The calibration module is used to determine whether the calibration of the battery pack is successful according to the theoretical electrical parameters and the actual electrical parameters.

11. A calibration device, characterized in that: include: at least one processor; as well as A memory, the memory is communicatively connected to the at least one processor, the memory stores instructions that can be executed by the at least one processor, the instructions are executed by the at least one processor so that the at least one processor can execute the method according to any one of claims 1 to 9.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the processor performs the steps of the method according to any one of claims 1 to 9.

Images