Method and device for determining battery pack offline voltage difference standard, and electronic equipment

Abstract

The application provides a battery pack offline voltage difference standard determination method and device and electronic equipment, including: determining the battery pack minimum energy requirement corresponding to the preset vehicle endurance mileage through a vehicle simulation model; determining the influence coefficient of the capacity unable to be exerted caused by the battery pack cell voltage difference based on the battery pack minimum energy requirement; determining the maximum SOC change corresponding to the cell voltage difference according to the influence coefficient of the capacity unable to be exerted caused by the cell voltage difference; determining the minimum cell voltage difference corresponding to the maximum SOC change in the SOC interval range of the cell offline test based on the maximum SOC change corresponding to the cell voltage difference; and correcting the minimum cell voltage difference by using the voltage collection error to obtain the battery pack offline voltage difference standard. In the method of the application, the reasonable battery pack offline voltage difference standard can be determined, the production can be optimized, and the situation that the cost is increased and the vehicle endurance mileage requirement is not met caused by excessive control can be avoided.

Description

Technical Field

[0001] This invention relates to the technical field of battery testing, and in particular to a method, apparatus, and electronic device for determining the standard of voltage difference between the lower terminals of a battery pack. Background Technology

[0002] In the new energy power battery industry, individual cells are assembled into battery packs according to certain processes. Since the voltage and capacity of a single cell are limited, the battery pack used in an electric vehicle is usually composed of hundreds or even thousands of individual cells. The parallel and series connection between cells ensures that the total voltage and total capacity of the battery pack meet the requirements of the electric vehicle.

[0003] For battery packs, the voltage difference between individual cells is one of the main indicators of cell consistency. Specifically, the smaller the voltage difference, the better the cell consistency, and the better the battery pack's discharge performance. Conversely, the larger the voltage difference, the worse the cell consistency, and the greater the impact on the battery pack's discharge performance, leading to insufficient discharge energy and affecting the electric vehicle's driving range. Therefore, voltage difference testing is necessary during battery pack off-line testing (off-line refers to leaving the production line). However, overly stringent voltage difference standards can lead to excessive process control, increasing costs, while overly lenient standards cannot guarantee the vehicle's driving range requirements. Therefore, designing a reasonable off-line voltage difference standard is crucial for meeting the vehicle's driving range requirements and controlling costs.

[0004] In summary, determining a reasonable standard for the voltage difference between battery pack terminals has become a pressing technical problem that needs to be solved. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a method, apparatus and electronic device for determining the standard of battery pack line voltage difference, so as to alleviate the technical problem that the prior art cannot determine a reasonable standard of battery pack line voltage difference.

[0006] In a first aspect, embodiments of the present invention provide a method for determining the standard of voltage difference at the lower limit of a battery pack, including:

[0007] The minimum energy requirements of the battery pack that meet the preset vehicle range are determined by using a whole vehicle simulation model.

[0008] The influence coefficient of the inability of the capacity to be fully utilized due to the voltage difference of the cells in the battery pack is determined based on the minimum energy requirement of the battery pack.

[0009] The maximum SOC change corresponding to the cell voltage difference is determined based on the influence coefficient of the cell voltage difference causing the capacity to be underutilized.

[0010] Based on the maximum SOC change corresponding to the cell voltage difference, determine the minimum cell voltage difference corresponding to the maximum SOC change within the SOC range of the cell offline test.

[0011] The minimum cell voltage difference is corrected by using voltage acquisition error to obtain the cell voltage difference within the battery pack, and the cell voltage difference within the battery pack is used as the standard for the battery pack's offline voltage difference.

[0012] Furthermore, the minimum energy requirements of the battery pack to meet the preset vehicle range are determined through a whole vehicle simulation model, including:

[0013] The vehicle parameters, reducer parameters, differential parameters, tire parameters, brake parameters, motor parameters, battery parameters, and the energy of multiple preset battery packs are input into the vehicle simulation model to obtain the vehicle range corresponding to the energy of each preset battery pack.

[0014] The minimum energy requirement of the battery pack corresponding to the preset vehicle range is determined based on the vehicle range corresponding to the energy of each preset battery pack.

[0015] Furthermore, based on the minimum energy requirement of the battery pack, the influence coefficient of the inability to fully utilize the capacity due to the voltage difference of the cells within the battery pack is determined, including:

[0016] The formula for calculating the impact coefficient of the inability to utilize the capacity due to the voltage difference between the cells in the battery pack is: A = Minimum energy requirement of the battery pack / Minimum energy of the cell * Total number of cells in the battery pack * Energy range of the battery pack * B * C * D. This calculates the impact coefficient of the inability to utilize the capacity due to the voltage difference between the cells in the battery pack, where A represents the impact coefficient of the inability to utilize the capacity due to the voltage difference between the cells in the battery pack, B represents the discharge cutoff voltage and error impact coefficient, C represents the charging cutoff voltage and error impact coefficient, and D represents the capacity loss during transportation and storage.

[0017] Furthermore, based on the influence coefficient of the cell voltage difference causing the capacity to be underutilized, the maximum SOC change corresponding to the cell voltage difference is determined, including:

[0018] The maximum SOC change corresponding to the cell voltage difference is obtained by subtracting the preset value from the influence coefficient of the cell voltage difference causing the capacity to be unable to be fully utilized.

[0019] Furthermore, based on the maximum SOC change corresponding to the cell voltage difference, the minimum cell voltage difference corresponding to the maximum SOC change is determined within the SOC range of the cell offline test, including:

[0020] In the SOC-OCV data, and within the SOC range, determine the minimum cell voltage difference corresponding to the maximum SOC change.

[0021] Furthermore, the minimum cell voltage difference is corrected using voltage acquisition error, including:

[0022] The voltage acquisition error of a preset multiple is summed with the minimum cell voltage difference to obtain the cell voltage difference within the battery pack.

[0023] Furthermore, the vehicle parameters include at least: vehicle weight, frontal area, wheelbase, drag coefficient, and rolling resistance coefficient.

[0024] Secondly, embodiments of the present invention also provide a device for determining the standard of voltage difference at the lower limit of a battery pack, comprising:

[0025] The first determining unit is used to determine the minimum energy requirements of the battery pack that meet the preset vehicle range through the whole vehicle simulation model;

[0026] The second determining unit is used to determine the influence coefficient of the inability of the capacity to be utilized due to the voltage difference of the cells in the battery pack based on the minimum energy requirement of the battery pack.

[0027] The third determining unit is used to determine the maximum SOC change corresponding to the cell voltage difference based on the influence coefficient of the cell voltage difference causing the capacity to be unable to be fully utilized.

[0028] The fourth determining unit is used to determine the minimum cell voltage difference corresponding to the maximum SOC change within the SOC range of the cell offline test based on the maximum SOC change corresponding to the cell voltage difference.

[0029] The correction unit is used to correct the minimum cell voltage difference using voltage acquisition error, obtain the cell voltage difference within the battery pack, and use the cell voltage difference within the battery pack as the standard for the battery pack's offline voltage difference.

[0030] Thirdly, embodiments of the present invention also provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method described in any of the first aspects above.

[0031] Fourthly, embodiments of the present invention also provide a computer-readable storage medium storing machine-executable instructions, which, when invoked and executed by a processor, cause the processor to perform the method described in any of the first aspects above.

[0032] In this embodiment of the invention, a method for determining the standard of battery pack decommissioning voltage difference is provided, comprising: determining the minimum energy requirement of the battery pack corresponding to meeting the preset vehicle range through a vehicle simulation model; determining the influence coefficient of the inability to utilize the capacity due to the cell voltage difference within the battery pack based on the minimum energy requirement of the battery pack; determining the maximum SOC change corresponding to the cell voltage difference based on the influence coefficient of the inability to utilize the capacity due to the cell voltage difference; determining the minimum cell voltage difference corresponding to the maximum SOC change within the SOC range of the cell decommissioning test based on the maximum SOC change corresponding to the cell voltage difference; correcting the minimum cell voltage difference using voltage acquisition error to obtain the cell voltage difference within the battery pack, and using the cell voltage difference within the battery pack as the standard of battery pack decommissioning voltage difference. As described above, the method for determining the battery pack voltage difference standard of the present invention is based on the minimum energy requirement of the battery pack required for the preset vehicle range. This battery pack voltage difference standard can meet the preset vehicle range requirements without being too stringent, thus determining a reasonable battery pack voltage difference standard. This reasonable battery pack voltage difference standard can optimize production and avoid situations where excessive control leads to increased costs and failure to meet the vehicle range requirements, thereby alleviating the technical problem that the prior art cannot determine a reasonable battery pack voltage difference standard. Attached Figure Description

[0033] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0034] Figure 1 A flowchart illustrating a method for determining the standard of voltage difference at the lower limit of a battery pack, provided in an embodiment of the present invention;

[0035] Figure 2 The flowchart of the method for determining the minimum energy requirement of the battery pack that meets the preset driving range by using a whole vehicle simulation model is provided in the embodiment of the present invention.

[0036] Figure 3 This is a schematic diagram showing that 0.25% of the capacity cannot be utilized after being discharged to a cutoff voltage of 2.805V, as provided in an embodiment of the present invention.

[0037] Figure 4 The data curve diagram of SOC-OCV provided in the embodiment of the present invention;

[0038] Figure 5This is a schematic diagram of a device for determining the standard of the voltage difference between the lower terminals of a battery pack, provided in an embodiment of the present invention.

[0039] Figure 6 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0040] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Current technology cannot determine a reasonable standard for the voltage difference at the end of the battery pack line.

[0042] Based on this, the method for determining the battery pack lower voltage difference standard of the present invention is to calculate the battery pack lower voltage difference standard by means of the minimum energy requirement of the battery pack required for the preset vehicle range. The battery pack lower voltage difference standard can meet the preset vehicle range requirements without being too stringent, that is, a reasonable battery pack lower voltage difference standard can be determined. Through the reasonable battery pack lower voltage difference standard, production can be optimized, and the situation of excessive control leading to increased costs and failure to meet the vehicle range requirements can be avoided.

[0043] To facilitate understanding of this embodiment, a method for determining the standard of battery pack line voltage difference disclosed in this embodiment of the invention will first be described in detail.

[0044] Example 1:

[0045] According to an embodiment of the present invention, an embodiment of a method for determining the standard of voltage difference of a battery pack is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0046] Figure 1 This is a flowchart of a method for determining the standard of battery pack line voltage difference according to an embodiment of the present invention, such as... Figure 1 As shown, the method includes the following steps:

[0047] Step S102: Determine the minimum energy requirements of the battery pack that meet the preset vehicle range using the whole vehicle simulation model;

[0048] Specifically, the above-mentioned vehicle simulation model can be an Amesim vehicle simulation model. This embodiment of the invention does not impose specific limitations on the above-mentioned vehicle simulation model, and it can also be other vehicle simulation models.

[0049] The aforementioned preset vehicle range is specifically the target vehicle range.

[0050] Step S104: Determine the influence coefficient of the inability to fully utilize the capacity due to the voltage difference of the cells in the battery pack based on the minimum energy requirement of the battery pack;

[0051] Step S106: Determine the maximum SOC change corresponding to the cell voltage difference based on the influence coefficient of the inability of the cell voltage difference to achieve its capacity.

[0052] The maximum SOC change corresponding to the cell voltage difference mentioned above refers to the maximum SOC change of the affected part corresponding to the cell voltage difference.

[0053] Step S108: Based on the maximum SOC change corresponding to the cell voltage difference, determine the minimum cell voltage difference corresponding to the maximum SOC change within the SOC range of the cell offline test.

[0054] Step S110: The minimum cell voltage difference is corrected by the voltage acquisition error to obtain the cell voltage difference in the battery pack, and the cell voltage difference in the battery pack is used as the standard for the battery pack's offline voltage difference.

[0055] In this embodiment of the invention, a method for determining the standard of battery pack decommissioning voltage difference is provided, comprising: determining the minimum energy requirement of the battery pack corresponding to meeting the preset vehicle range through a vehicle simulation model; determining the influence coefficient of the inability to utilize the capacity due to the cell voltage difference within the battery pack based on the minimum energy requirement of the battery pack; determining the maximum SOC change corresponding to the cell voltage difference based on the influence coefficient of the inability to utilize the capacity due to the cell voltage difference; determining the minimum cell voltage difference corresponding to the maximum SOC change within the SOC range of the cell decommissioning test based on the maximum SOC change corresponding to the cell voltage difference; correcting the minimum cell voltage difference using voltage acquisition error to obtain the cell voltage difference within the battery pack, and using the cell voltage difference within the battery pack as the standard of battery pack decommissioning voltage difference. As described above, the method for determining the battery pack voltage difference standard of the present invention is based on the minimum energy requirement of the battery pack required for the preset vehicle range. This battery pack voltage difference standard can meet the preset vehicle range requirements without being too stringent, thus determining a reasonable battery pack voltage difference standard. This reasonable battery pack voltage difference standard can optimize production and avoid situations where excessive control leads to increased costs and failure to meet the vehicle range requirements, thereby alleviating the technical problem that the prior art cannot determine a reasonable battery pack voltage difference standard.

[0056] The above briefly introduces the method for determining the battery pack line voltage difference standard of the present invention. The specific contents involved are described in detail below.

[0057] In an alternative embodiment of the present invention, reference is made to... Figure 2 The minimum energy requirements of the battery pack to meet the preset vehicle range are determined through a whole vehicle simulation model. The specific steps include the following:

[0058] Step S201: Input the vehicle parameters, reducer parameters, differential parameters, tire parameters, brake parameters, motor parameters, battery parameters and multiple preset battery pack energies into the vehicle simulation model to obtain the vehicle range corresponding to the energy of each preset battery pack.

[0059] Specifically, the above-mentioned vehicle parameters include at least: vehicle weight, frontal area, wheelbase, drag coefficient, and rolling resistance coefficient.

[0060] Step S202: Determine the minimum energy requirement of the battery pack that meets the preset vehicle range based on the vehicle range corresponding to the energy of each preset battery pack.

[0061] Specifically, for example: the vehicle range corresponding to the energy of each preset battery pack is: the vehicle range corresponding to the energy of a 50 kWh battery pack is 400 km, the vehicle range corresponding to the energy of a 40 kWh battery pack is 300 km, and the preset vehicle range is 400 km, then the minimum energy requirement of the corresponding battery pack is 50 kWh.

[0062] In an optional embodiment of the present invention, the influence coefficient of the inability of the battery pack's capacity to be fully utilized due to the voltage difference between the cells within the battery pack is determined based on the minimum energy requirement of the battery pack, specifically including the following steps:

[0063] The formula for calculating the impact coefficient of the inability to fully utilize the capacity due to the voltage difference between the cells in the battery pack is: A = Minimum energy requirement of the battery pack / Minimum energy of the cell * Total number of cells in the battery pack * Energy range of the battery pack * B * C * D. This calculates the impact coefficient of the inability to fully utilize the capacity due to the voltage difference between the cells in the battery pack, where A represents the impact coefficient of the inability to fully utilize the capacity due to the voltage difference between the cells in the battery pack, B represents the discharge cutoff voltage and error impact coefficient, C represents the charging cutoff voltage and error impact coefficient, and D represents the capacity loss during transportation and storage.

[0064] The above calculation formula is explained below:

[0065] The aforementioned coefficient B is determined based on the system discharge cutoff voltage, the cell discharge cutoff voltage, and the voltage acquisition error. For example, if the cell discharge cutoff voltage is 2.7V, while the system discharge cutoff voltage is 2.8V, and the voltage acquisition error is 5mV, then the influence coefficient of the system discharge cutoff voltage of 2.805V relative to the cell discharge cutoff voltage of 2.7V needs to be considered. This coefficient is calculated as follows: the difference between the capacity value corresponding to 2.805V and the capacity value corresponding to 2.7V, divided by the capacity value corresponding to 2.7V, yields the unutilized capacity. Figure 3 The 0.25% of the capacity value is obtained from the experimental data of the actual battery cell. It represents the capacity value that can be discharged from a full charge to this voltage (there will be multiple capacity values ​​for different battery cells, but the ratio of the capacity difference between the two voltages to the total capacity remains basically unchanged).

[0066] Figure 3 The diagram shows that after a discharge cutoff of 2.805V, 0.25% of the capacity will not be utilized. Therefore, coefficient B can be determined as 1 - 0.25% = 99.75% (representing the percentage of capacity actually utilized). Similarly, during the charging process, the same considerations as the charging cutoff voltage are required, thus obtaining the influence coefficient C.

[0067] The coefficient D takes into account the time that the battery pack will be transported and stored from production until the user uses it. Therefore, the energy loss during transportation and storage needs to be considered in the calculation of the minimum capacity. This coefficient can be confirmed based on the cell storage test data (which is known and provided by the cell manufacturer, showing how long the transportation and storage lasted at a certain temperature and how much energy was lost).

[0068] The minimum energy of the battery cells mentioned above is also given by the battery cell manufacturer. If a battery cell manufacturer produces 1,000 battery cells, it will give the minimum energy value of those 1,000 battery cells.

[0069] The total number of cells in the aforementioned battery pack can also be determined based on the battery pack design scheme.

[0070] The above-mentioned battery pack energy range represents the SOC range used by the whole vehicle. For example, the SOC range used by the whole vehicle is 5%-95%, which is given by the vehicle manufacturer or recommended by the cell manufacturer. The battery pack energy range here is the difference between the upper limit and the lower limit of the battery pack energy range. For example, if the battery pack energy range is 5%-95%, in the calculation, the battery pack energy range = 95% - 5% = 90%.

[0071] Specifically, if the minimum energy requirement of the battery pack, the minimum energy of the cell, the total number of cells in the battery pack, the energy range of the battery pack, and B, C, and D are all determined, then the influence coefficient A of the cell voltage difference causing the capacity to be underutilized can be calculated.

[0072] In an optional embodiment of the present invention, determining the maximum SOC change corresponding to the cell voltage difference based on the influence coefficient of the cell voltage difference causing the capacity to be underutilized specifically includes:

[0073] The maximum SOC change corresponding to the cell voltage difference is obtained by subtracting the preset value from the influence coefficient of the cell voltage difference causing the capacity to be unable to be fully utilized.

[0074] Specifically, based on the calculated influence coefficient of the cell voltage difference causing the capacity to be underutilized, the maximum SOC change corresponding to the cell voltage difference is calculated (i.e., the maximum ΔSOC of the affected portion corresponding to the cell voltage difference). For example, if the calculated influence coefficient of the cell voltage difference causing the capacity to be underutilized is 94%, then the maximum SOC change corresponding to the cell voltage difference is 1 - 94% = 6%.

[0075] It should be noted that the above preset value can be 1.

[0076] In an optional embodiment of the present invention, based on the maximum SOC change corresponding to the cell voltage difference, the minimum cell voltage difference corresponding to the maximum SOC change is determined within the SOC range of the cell offline test, specifically including:

[0077] In the SOC-OCV data, and within the SOC range, determine the minimum cell voltage difference corresponding to the maximum SOC change.

[0078] Specifically, the SOC range mentioned above for cell off-line testing refers to the SOC range of the cell after it leaves the production line. Figure 4 The data curves of SOC-OCV are shown, from which the minimum cell voltage difference corresponding to the maximum SOC change of 6% within the SOC range is determined to be 70mV.

[0079] In an optional embodiment of the present invention, the minimum cell voltage difference is corrected using voltage acquisition error, specifically including:

[0080] The voltage acquisition error of a preset multiple is summed with the minimum cell voltage difference to obtain the cell voltage difference within the battery pack.

[0081] Specifically, the offline voltage difference is an actual test item, and therefore inevitably affected by the BMS voltage acquisition error (±5mV). Considering the worst-case scenario, to avoid a situation where the measured voltage is 70mV but the actual voltage is 80mV (the cell voltage difference is a difference, which requires subtracting the voltage values ​​of two cells separately. Although the actual difference between the two cell voltage values ​​is 70mV, this difference is calculated from the two measured values, which can be higher and lower; therefore, to avoid an 80mV situation), the final offline voltage difference standard setting is determined to be 70mV - 10mV = 60mV. This means adding twice the voltage acquisition error to the minimum cell voltage difference to obtain the cell voltage difference within the battery pack, and using this cell voltage difference within the battery pack as the standard for the battery pack's offline voltage difference.

[0082] The method of the present invention can reasonably determine the standard voltage difference of the battery pack at the end of the production line while ensuring the driving range of the whole vehicle. It can optimize production and avoid the situation where excessive control leads to increased costs and failure to meet the driving range requirements of the whole vehicle.

[0083] The method of this invention uses the calculation formula for the minimum energy requirement of the battery pack and takes into account the maximum acquisition deviation parameter of the BMS. In the process of determining the voltage difference, the most stringent conditions of each parameter are considered to the maximum extent, which can fully ensure the satisfaction of the vehicle's driving range. The method for determining the voltage difference standard is given and its connection with the actual driving range requirement of the vehicle is given. The calculation examples of each step of the battery pack voltage difference standard calculation are clarified, which is portable.

[0084] Example 2:

[0085] This invention also provides a device for determining the standard of battery pack offline voltage difference. This device is mainly used to execute the method for determining the standard of battery pack offline voltage difference provided in Embodiment 1 of this invention. The following is a detailed description of the device for determining the standard of battery pack offline voltage difference provided in this invention.

[0086] Figure 5 This is a schematic diagram of a device for determining the standard of battery pack line voltage difference according to an embodiment of the present invention, as shown below. Figure 5 As shown, the device mainly includes: a first determining unit 10, a second determining unit 20, a third determining unit 30, a fourth determining unit 40, and a correction unit 50, wherein:

[0087] The first determining unit is used to determine the minimum energy requirements of the battery pack that meet the preset vehicle range through the whole vehicle simulation model;

[0088] The second determining unit is used to determine the influence coefficient of the inability of the capacity to be utilized due to the voltage difference of the cells in the battery pack based on the minimum energy requirement of the battery pack.

[0089] The third determining unit is used to determine the maximum SOC change corresponding to the cell voltage difference based on the influence coefficient of the cell voltage difference causing the capacity to be unable to be fully utilized.

[0090] The fourth determining unit is used to determine the minimum cell voltage difference corresponding to the maximum SOC change within the SOC range of the cell offline test, based on the maximum SOC change corresponding to the cell voltage difference.

[0091] The correction unit is used to correct the minimum cell voltage difference using voltage acquisition error, obtain the cell voltage difference within the battery pack, and use the cell voltage difference within the battery pack as the standard for the battery pack's offline voltage difference.

[0092] In this embodiment of the invention, a device for determining the standard of battery pack decommissioning voltage difference is provided, comprising: determining the minimum energy requirement of the battery pack corresponding to meeting the preset vehicle range through a vehicle simulation model; determining the influence coefficient of the inability to utilize the capacity due to the cell voltage difference within the battery pack based on the minimum energy requirement of the battery pack; determining the maximum SOC change corresponding to the cell voltage difference based on the influence coefficient of the inability to utilize the capacity due to the cell voltage difference; determining the minimum cell voltage difference corresponding to the maximum SOC change within the SOC range of the cell decommissioning test based on the maximum SOC change corresponding to the cell voltage difference; correcting the minimum cell voltage difference using voltage acquisition error to obtain the cell voltage difference within the battery pack, and using the cell voltage difference within the battery pack as the standard of battery pack decommissioning voltage difference. As described above, the battery pack voltage difference standard determination device of the present invention is based on the battery pack voltage difference standard calculated by pre-setting the minimum energy requirement of the battery pack for the vehicle's driving range. This battery pack voltage difference standard can meet the requirements of the preset vehicle driving range without being too stringent, thus determining a reasonable battery pack voltage difference standard. This reasonable battery pack voltage difference standard can optimize production and avoid situations where excessive control leads to increased costs and failure to meet the vehicle's driving range requirements, thereby alleviating the technical problem that the prior art cannot determine a reasonable battery pack voltage difference standard.

[0093] Optionally, the first determining unit is further configured to: input vehicle parameters, reducer parameters, differential parameters, tire parameters, brake parameters, motor parameters, battery parameters, and multiple preset battery pack energies into the vehicle simulation model to obtain the vehicle range corresponding to the energy of each preset battery pack; and determine the minimum energy requirement of the battery pack corresponding to the preset vehicle range based on the vehicle range corresponding to the energy of each preset battery pack.

[0094] Optionally, the second determining unit is further configured to: calculate the influence coefficient of the inability to utilize capacity due to the voltage difference between cells in the battery pack based on the formula: A = minimum energy requirement of battery pack / minimum energy of cell * total number of cells in battery pack * energy range of battery pack * B * C * D, where A represents the influence coefficient of the inability to utilize capacity due to the voltage difference between cells in the battery pack, B represents the influence coefficient of discharge cutoff voltage and error, C represents the influence coefficient of charging cutoff voltage and error, and D represents the capacity loss during transportation and storage.

[0095] Optionally, the third determining unit is further configured to: subtract a preset value from the influence coefficient of the inability of the capacity to be fully utilized due to the cell voltage difference, and obtain the maximum SOC change corresponding to the cell voltage difference.

[0096] Optionally, the fourth determining unit is further configured to: determine the minimum cell voltage difference corresponding to the maximum SOC change in the SOC-OCV data and within the SOC range.

[0097] Optionally, the correction unit is also used to: sum the voltage acquisition error of a preset multiple with the minimum cell voltage difference to obtain the cell voltage difference in the battery pack.

[0098] Optionally, the vehicle parameters may include at least: vehicle weight, frontal area, wheelbase, drag coefficient, and rolling resistance coefficient.

[0099] The device provided in this embodiment of the invention has the same implementation principle and technical effect as the aforementioned method embodiment. For the sake of brevity, any parts not mentioned in the device embodiment can be referred to the corresponding content in the aforementioned method embodiment.

[0100] like Figure 6 As shown in the embodiment of this application, an electronic device 600 includes a processor 601, a memory 602, and a bus. The memory 602 stores machine-readable instructions that can be executed by the processor 601. When the electronic device is running, the processor 601 communicates with the memory 602 via the bus. The processor 601 executes the machine-readable instructions to perform the steps of the method for determining the battery pack offline voltage difference standard as described above.

[0101] Specifically, the memory 602 and processor 601 mentioned above can be general-purpose memory and processor, without any specific limitations. When the processor 601 runs the computer program stored in the memory 602, it can execute the method for determining the standard of the battery pack's lower voltage difference.

[0102] The processor 601 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of the processor 601 or by instructions in software form. The processor 601 may be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it may 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, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly manifested as execution by a hardware decoding processor, or execution by a combination of hardware and software modules in the decoding processor. The software module can reside in a mature storage medium in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory 602, and processor 601 reads the information from memory 602 and, in conjunction with its hardware, completes the steps of the above method.

[0103] Corresponding to the above-mentioned method for determining the standard of the battery pack's offline voltage difference, this application embodiment also provides a computer-readable storage medium storing machine-executable instructions. When the machine-executable instructions are called and run by a processor, the machine-executable instructions cause the processor to perform the steps of the above-mentioned method for determining the standard of the battery pack's offline voltage difference.

[0104] The device for determining the battery pack offline voltage difference standard provided in this application embodiment can be specific hardware on the device or software or firmware installed on the device. The implementation principle and technical effects of the device provided in this application embodiment are the same as those in the foregoing method embodiments. For the sake of brevity, any parts not mentioned in the device embodiment can be referred to the corresponding content in the foregoing method embodiments. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can all be referred to the corresponding processes in the above method embodiments, and will not be repeated here.

[0105] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0106] For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0107] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0108] In addition, the functional units in the embodiments provided in this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0109] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause an electronic device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the vehicle marking method described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0110] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In addition, the terms "first", "second", "third", etc. are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0111] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this application; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application. All should be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A method for determining the standard of voltage difference between the lower terminals of a battery pack, characterized in that, include: The minimum energy requirements of the battery pack that meet the preset vehicle range are determined by using a whole vehicle simulation model. The influence coefficient of the inability of the capacity to be fully utilized due to the voltage difference of the cells in the battery pack is determined based on the minimum energy requirement of the battery pack. The maximum SOC change corresponding to the cell voltage difference is determined based on the influence coefficient of the cell voltage difference causing the capacity to be underutilized. Based on the maximum SOC change corresponding to the cell voltage difference, determine the minimum cell voltage difference corresponding to the maximum SOC change within the SOC range of the cell offline test. The minimum cell voltage difference is corrected by using voltage acquisition error to obtain the cell voltage difference within the battery pack, and the cell voltage difference within the battery pack is used as the standard for the battery pack's offline voltage difference. Among them, the influence coefficient of the inability to fully utilize the capacity due to the voltage difference of the cells in the battery pack is determined based on the minimum energy requirement of the battery pack, including: The formula for calculating the impact coefficient of the inability to utilize the capacity due to the voltage difference of the cells in the battery pack is: A = Minimum energy requirement of the battery pack / (Minimum energy of the cells * Total number of cells in the battery pack * Energy range used by the battery pack * B * C * D). Here, A represents the impact coefficient of the inability to utilize the capacity due to the voltage difference of the cells in the battery pack, B represents the discharge cutoff voltage and error impact coefficient, C represents the charging cutoff voltage and error impact coefficient, and D represents the capacity loss during transportation and storage.

2. The method according to claim 1, characterized in that, The minimum energy requirements of the battery pack to meet the preset vehicle range were determined through a whole vehicle simulation model, including: The vehicle parameters, reducer parameters, differential parameters, tire parameters, brake parameters, motor parameters, battery parameters, and multiple preset battery pack energies are input into the vehicle simulation model to obtain the vehicle range corresponding to the energy of each preset battery pack. The minimum energy requirement of the battery pack corresponding to the preset vehicle range is determined based on the vehicle range corresponding to the energy of each preset battery pack.

3. The method according to claim 1, characterized in that, The maximum SOC change corresponding to the cell voltage difference is determined based on the influence coefficient of the cell voltage difference causing the capacity to be underutilized, including: The maximum SOC change corresponding to the cell voltage difference is obtained by subtracting the preset value from the influence coefficient of the cell voltage difference causing the capacity to be unable to be fully utilized.

4. The method according to claim 1, characterized in that, Based on the maximum SOC change corresponding to the cell voltage difference, determine the minimum cell voltage difference corresponding to the maximum SOC change within the SOC range of the cell offline test, including: In the SOC-OCV data, and within the SOC range, determine the minimum cell voltage difference corresponding to the maximum SOC change.

5. The method according to claim 1, characterized in that, The minimum cell voltage difference is corrected using voltage acquisition error, including: The voltage acquisition error of a preset multiple is summed with the minimum cell voltage difference to obtain the cell voltage difference within the battery pack.

6. The method according to claim 2, characterized in that, The vehicle parameters include at least: vehicle weight, frontal area, wheelbase, drag coefficient, and rolling resistance coefficient.

7. A device for determining the standard of voltage difference between the lower terminals of a battery pack, characterized in that, include: The first determining unit is used to determine the minimum energy requirements of the battery pack that meet the preset vehicle range through the whole vehicle simulation model; The second determining unit is used to determine the influence coefficient of the inability of the capacity to be utilized due to the voltage difference of the cells in the battery pack based on the minimum energy requirement of the battery pack. The third determining unit is used to determine the maximum SOC change corresponding to the cell voltage difference based on the influence coefficient of the cell voltage difference causing the capacity to be unable to be fully utilized. The fourth determining unit is used to determine the minimum cell voltage difference corresponding to the maximum SOC change within the SOC range of the cell offline test based on the maximum SOC change corresponding to the cell voltage difference. The correction unit is used to correct the minimum cell voltage difference using voltage acquisition error, obtain the cell voltage difference in the battery pack, and use the cell voltage difference in the battery pack as the standard for the battery pack's offline voltage difference. The second determining unit is further configured to: calculate the influence coefficient of the inability to utilize capacity due to the voltage difference of the cells in the battery pack based on the following formula: A = minimum energy requirement of the battery pack / (minimum energy of the cell * total number of cells in the battery pack * energy range used by the battery pack * B * C * D), where A represents the influence coefficient of the inability to utilize capacity due to the voltage difference of the cells in the battery pack, B represents the influence coefficient of discharge cutoff voltage and error, C represents the influence coefficient of charging cutoff voltage and error, and D represents the capacity loss during transportation and storage.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores machine-executable instructions that, when invoked and executed by a processor, cause the processor to perform the method according to any one of claims 1 to 6.

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