Methods, apparatus, electronic devices, and storage media for determining the state of harmonics (SOH) relationship in hybrid batteries

Abstract

This application relates to a method, apparatus, electronic device, and storage medium for determining the state of health (SOH) of a hybrid battery. The method includes: determining a first peak point based on the dV / dQ curve of a first battery pack; determining a corresponding first OCV-SOC curve point in the OCV-SOC curve of a second battery pack based on the first peak point of the first battery pack, and determining a corresponding second OCV-SOC curve point in the OCV-SOC curve of the second battery pack based on the maximum dV / dQ curve point corresponding to the maximum SOC value of the first battery pack; determining the real-time voltage difference at the current time point based on the first and second OCV-SOC curve points, and determining the SOH mapping relationship between the first and second battery packs based on the real-time voltage difference and the initial voltage difference corresponding to the hybrid battery at the time of manufacture. This application solves the technical problem of low estimation accuracy of the health status of lithium iron phosphate batteries in related technologies and improves the estimation accuracy of the health status of lithium iron phosphate batteries.

Description

Technical Field

[0001] This application relates to the field of battery testing, and in particular to a method, apparatus, electronic device, and storage medium for determining the SOH relationship of a hybrid battery. Background Technology

[0002] Due to their high safety profile, lithium iron phosphate (LFP) batteries have become increasingly popular in new energy vehicles in recent years. However, LFP batteries suffer from poor low-temperature performance and low state of charge (SOC) estimation accuracy, leading to a less than ideal user experience.

[0003] To avoid the aforementioned drawbacks of lithium iron phosphate (LFP) batteries, related technologies typically combine ternary lithium batteries (which have better low-temperature performance and higher SOC estimation accuracy) with LFP batteries to form an AB hybrid battery. This utilizes the advantages of both LFP and ternary lithium batteries. For example, leveraging the good low-temperature performance of ternary lithium batteries, they are placed in a position where heat dissipation is faster in the hybrid battery, thus insulating the LFP batteries. Simultaneously, the SOC value of the LFP battery is estimated using the mapping relationship between the SOC values ​​of the ternary lithium battery and the LFP battery. However, due to the significant difference in aging rates between LFP and ternary lithium batteries, the mapping relationship between the SOC values ​​of aged LFP and ternary lithium batteries needs to be recalibrated. This recalibration requires accurate calculation of the SOC values ​​of both LFP and ternary lithium batteries, which is often difficult to calculate accurately. Therefore, the relevant technologies cannot obtain an accurate mapping relationship between the SOC values ​​of lithium iron phosphate batteries and ternary lithium batteries, which leads to low accuracy in estimating the health status of lithium iron phosphate batteries.

[0004] There is currently no effective solution to the technical problem of low accuracy in estimating the health status of lithium iron phosphate batteries in related technologies. Summary of the Invention

[0005] This embodiment provides a method, apparatus, electronic device, and storage medium for determining the state of health (SOH) of a hybrid battery, in order to address the problem of low accuracy in estimating the health status of lithium iron phosphate batteries in related technologies.

[0006] Firstly, this embodiment provides a method for determining the state-ohm relationship of a hybrid battery, the hybrid battery comprising a first battery pack and a second battery pack, including:

[0007] Based on the dV / dQ curve of the first battery pack, a first peak point is determined. The first peak point is the peak point with the largest SOC value among multiple peak points of the dV / dQ curve.

[0008] Based on the first peak point of the first battery pack, the corresponding first OCV-SOC curve point is determined in the OCV-SOC curve of the second battery pack, and based on the maximum dV / dQ curve point corresponding to the maximum SOC value of the first battery pack, the corresponding second OCV-SOC curve point is determined in the OCV-SOC curve of the second battery pack.

[0009] Based on the first OCV-SOC curve point and the second OCV-SOC curve point, the real-time voltage difference corresponding to the current time point is determined, and based on the real-time voltage difference and the initial voltage difference corresponding to the hybrid battery at the time of manufacture, the SOH mapping relationship between the first battery pack and the second battery pack is determined.

[0010] In some embodiments, the process of determining the SOH mapping relationship between the first battery pack and the second battery pack further includes:

[0011] Obtain the real-time charging amount of the first battery pack from the first peak point to the maximum dV / dQ curve point, and the initial charging amount of the hybrid battery when it leaves the factory;

[0012] Based on the real-time charging amount and the initial charging amount, the first SOH value of the first battery pack is determined.

[0013] In some embodiments, the process of determining the SOH mapping relationship between the first battery pack and the second battery pack further includes:

[0014] The current battery capacity of the second battery pack is determined based on the real-time voltage difference of the second battery pack and the real-time charging amount of the first battery pack.

[0015] The initial battery capacity of the second battery pack is determined based on the initial voltage difference of the second battery pack and the initial charge amount of the first battery pack.

[0016] Based on the current battery capacity and the initial battery capacity, the second SOH value of the second battery pack is determined.

[0017] In some embodiments, determining the SOH mapping relationship between the first battery pack and the second battery pack includes:

[0018] Based on the first SOH value and the second SOH value, the SOH mapping relationship between the first battery pack and the second battery pack is determined.

[0019] In some embodiments, determining the SOH mapping relationship between the first battery pack and the second battery pack includes:

[0020] Determine whether the real-time SOC value of the first battery pack increases from the SOC value corresponding to the first peak point to the maximum SOC value within a preset time period, and obtain a first determination result;

[0021] Determine whether the rate of change of the slope of the OCV-SOC curve segment between the first OCV-SOC curve point and the second OCV-SOC curve point of the second battery pack is lower than a preset threshold, and obtain a second determination result;

[0022] If both the first and second judgment results meet the conditions, then the SOH mapping relationship between the first battery pack and the second battery pack is determined.

[0023] In some embodiments, if at least one of the first judgment result and the second judgment result does not meet the condition, the second SOH value of the second battery pack is obtained, and the first SOH value of the first battery pack is determined based on the historical SOH mapping relationship between the first battery pack and the second battery pack.

[0024] In some embodiments, the first battery pack includes a lithium iron phosphate battery pack, and the second battery pack includes a ternary lithium battery pack.

[0025] Secondly, this embodiment provides a device for determining the state-of-the-art (SOH) relationship of a hybrid battery, the hybrid battery comprising a first battery pack and a second battery pack, including:

[0026] The first determining module is used to determine a first peak point based on the dV / dQ curve of the first battery pack. The first peak point is the peak point with the largest SOC value among multiple peak points of the dV / dQ curve.

[0027] The second determining module is used to determine the corresponding first OCV-SOC curve point in the OCV-SOC curve of the second battery pack based on the first peak point of the first battery pack, and to determine the corresponding second OCV-SOC curve point in the OCV-SOC curve of the second battery pack based on the maximum dV / dQ curve point corresponding to the maximum SOC value of the first battery pack.

[0028] The third determining module is used to determine the real-time voltage difference corresponding to the current time point based on the first OCV-SOC curve point and the second OCV-SOC curve point, and to determine the SOH mapping relationship between the first battery pack and the second battery pack based on the real-time voltage difference and the initial voltage difference corresponding to the hybrid battery at the time of manufacture.

[0029] Thirdly, this embodiment provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the method for determining the state-ohm relationship of a hybrid battery as described in the first aspect.

[0030] Fourthly, this embodiment provides a storage medium storing a computer program that, when executed by a processor, implements the method for determining the SOH relationship of the hybrid battery described in the first aspect.

[0031] Compared with related technologies, this application provides a method, apparatus, electronic device, and storage medium for determining the SOH relationship of a hybrid battery. The method includes: determining a first peak point based on the dV / dQ curve of a first battery pack, wherein the first peak point is the peak point with the largest SOC value among multiple peak points of the dV / dQ curve; determining a corresponding first OCV-SOC curve point in the OCV-SOC curve of a second battery pack based on the first peak point of the first battery pack, and determining a corresponding second OCV-SOC curve point in the OCV-SOC curve of the second battery pack based on the maximum dV / dQ curve point corresponding to the maximum SOC value of the first battery pack; determining the real-time voltage difference corresponding to the current time point based on the first OCV-SOC curve point and the second OCV-SOC curve point, and determining the SOH mapping relationship between the first battery pack and the second battery pack based on the real-time voltage difference and the initial voltage difference corresponding to the hybrid battery at the time of manufacture. Compared to existing technologies that estimate the SOH value of lithium iron phosphate batteries through a mapping relationship, this application presents a linear relationship with a large slope between the first OCV-SOC curve point and the second OCV-SOC curve point. Therefore, estimating the SOH value of lithium iron phosphate batteries using the SOH value of ternary lithium batteries can effectively improve the estimation accuracy of SOH values. Furthermore, it eliminates the need to obtain the SOC value of lithium iron phosphate batteries, solving the technical problem of low estimation accuracy of the health status of lithium iron phosphate batteries in related technologies. This improves the accuracy of the correlation between the health status of lithium iron phosphate batteries and ternary lithium batteries, and the calibration method for the SOH mapping relationship is simple, thereby improving the estimation accuracy of the health status of lithium iron phosphate batteries and reducing the estimation cost.

[0032] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0033] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0034] Figure 1 This is a terminal hardware structure block diagram of a hybrid battery SOH relationship determination method according to an embodiment of this application;

[0035] Figure 2 This is a flowchart illustrating a method for determining the SOH relationship of a hybrid battery according to an embodiment of this application.

[0036] Figure 3 This is a schematic diagram of the dV / dQ curve of the first battery pack and the OCV-SOC curve of the second battery pack according to an embodiment of this application;

[0037] Figure 4 This is a structural block diagram of a hybrid battery SOH relationship determination device according to an embodiment of this application. Detailed Implementation

[0038] To better understand the purpose, technical solution, and advantages of this application, the application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0039] Unless otherwise defined, the technical or scientific terms used in this application shall have the general meaning as understood by one of ordinary skill in the art to which this application pertains. Words such as “a,” “an,” “an,” “the,” “the,” and “these,” used in this application, do not indicate quantitative limitation and may be singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that comprises a series of steps or modules (units) is not limited to the listed steps or modules (units) but may include steps or modules (units) not listed, or may include other steps or modules (units) inherent to such processes, methods, products, or devices. The terms “connected,” “linked,” and “coupled,” used in this application, are not limited to physical or mechanical connections but may include electrical connections, whether direct or indirect. The term “multiple” used in this application refers to two or more. The "and / or" operator describes the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: A alone, A and B simultaneously, and B alone. Typically, the character " / " indicates that the objects before and after it are in an "or" relationship. The terms "first," "second," and "third," etc., used in this application are merely for distinguishing similar objects and do not represent a specific ordering of the objects.

[0040] The method embodiments provided in this example can be executed on a terminal, computer, or similar computing device. For example, it can run on a terminal. Figure 1 This is a hardware structure block diagram of the terminal for the method of determining the SOH relationship of a hybrid battery in this embodiment. (See diagram for example.) Figure 1 As shown, a terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 and a memory 104 for storing data are also included. The processor 102 may be, but is not limited to, a microprocessor (MCU) or a programmable logic device (FPGA). The terminal may also include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that… Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the terminal described above. For example, the terminal may also include components that are larger than... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown are illustrated.

[0041] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the method for determining the SOH relationship of a hybrid battery in this embodiment. The processor 102 executes various functional applications and data processing by running the computer programs stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0042] The transmission device 106 is used to receive or send data via a network. This network includes a wireless network provided by the terminal's communication provider. In one example, the transmission device 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 106 can be a Radio Frequency (RF) module used for wireless communication with the Internet.

[0043] For example, the SOC value in this application refers to the current remaining charge of the battery; the SOH value in this application refers to the current remaining capacity of the battery, that is, the percentage of the current capacity of the battery to the factory capacity.

[0044] For example, the process of plotting the dV / dQ curve in this application includes: charging and discharging a small current battery and recording the charging and discharging parameters, namely, the energy data and voltage data; plotting the dV / dQ curve using the ratio of the energy difference (dQ) formed by subtracting the nth energy data and voltage data from the (n+1)th energy data and voltage data from the nth energy data and voltage data, and the voltage difference (dV / dQ). In this application, the horizontal axis is set to the SOC value, and the vertical axis is dV / dQ. The OCV-SOC curve in this application refers to the curve formed by the correspondence between the battery's open-circuit voltage and the SOC value.

[0045] Please see Figures 2-3 , Figure 2 This is a flowchart illustrating a method for determining the state-ohm (SOH) relationship of a hybrid battery according to an embodiment of this application. Figure 3 This is a schematic diagram of the dV / dQ curve of the first battery pack and the OCV-SOC curve of the second battery pack according to an embodiment of this application.

[0046] In one embodiment, such as Figure 2 As shown, the hybrid battery includes a first battery pack and a second battery pack. The method for determining the SOH relationship of the hybrid battery includes:

[0047] S202: Based on the dV / dQ curve of the first battery pack, determine the first peak point, which is the peak point with the largest SOC value among multiple peak points of the dV / dQ curve.

[0048] For example, measurements are taken on the first battery pack to obtain the corresponding dV / dQ curve, such as... Figure 2 The LFP-dVdQ curve is shown in the figure. The horizontal axis of the dV / dQ curve represents the State of Charge (SOC) value of the first battery pack, and the vertical axis represents the dV / dQ value. Based on the dV / dQ curve, multiple peak points are identified, and the peak point with the highest SOC value is selected as the first peak point, as shown below. Figure 2 The dVHi point is shown in the figure.

[0049] S204: Based on the first peak point of the first battery pack, determine the corresponding first OCV-SOC curve point in the OCV-SOC curve of the second battery pack, and based on the maximum dV / dQ curve point corresponding to the maximum SOC value of the first battery pack, determine the corresponding second OCV-SOC curve point in the OCV-SOC curve of the second battery pack.

[0050] For example, measurements are taken on the second battery pack to obtain the corresponding OCV-SOC curve, which is the relationship curve between the open-circuit voltage and the SOC value of the second battery pack. Figure 2 The NCM-Volt curve is shown. Since the first and second battery packs are AB hybrid batteries connected in series, there is a correlation in their electrical parameters. By using the first peak point of the first battery pack, the corresponding first OCV-SOC curve point can be determined in the OCV-SOC curve of the second battery pack, as shown below. Figure 2 The Ka point in the curve, obtained by using the maximum dV / dQ curve point corresponding to the maximum SOC value of the first battery pack, can be used to determine the corresponding second OCV-SOC curve point in the OCV-SOC curve of the second battery pack. For example... Figure 2 The Kb point is the maximum SOC value, which represents 100% of the remaining battery capacity.

[0051] S206: Based on the first OCV-SOC curve point and the second OCV-SOC curve point, determine the real-time voltage difference corresponding to the current time point, and based on the real-time voltage difference and the initial voltage difference corresponding to the hybrid battery at the time of manufacture, determine the SOH mapping relationship between the first battery pack and the second battery pack.

[0052] For example, after obtaining the first OCV-SOC curve point and the second OCV-SOC curve point of the second battery pack, the voltage difference between the two is calculated as the real-time voltage difference of the second battery pack at the current time point. Further, the initial voltage difference corresponding to the first OCV-SOC curve point and the second OCV-SOC curve point of the hybrid battery at the time of manufacture is obtained. The SOH mapping relationship between the first battery pack and the second battery pack is determined by comparing the real-time voltage difference with the initial voltage difference.

[0053] Specifically, in this embodiment, the aging rate of the first battery pack is faster than that of the second battery pack. By measuring the SOH value of the second battery pack, the SOH value of the first battery pack can be determined through the SOH value of the second battery pack and the SOH mapping relationship between the first and second battery packs. Thus, the health status of the first battery pack can be estimated through the stable second battery pack, and the accuracy of the estimation results can be improved.

[0054] Specifically, in this embodiment, the first battery pack can be configured as a lithium iron phosphate battery pack, and the second battery pack can be configured as a ternary lithium battery pack.

[0055] In this embodiment, a first peak point is determined based on the dV / dQ curve of the first battery pack. The first peak point is the peak point with the largest SOC value among multiple peak points of the dV / dQ curve. Based on the first peak point of the first battery pack, a corresponding first OCV-SOC curve point is determined in the OCV-SOC curve of the second battery pack. Based on the maximum dV / dQ curve point corresponding to the maximum SOC value of the first battery pack, a corresponding second OCV-SOC curve point is determined in the OCV-SOC curve of the second battery pack. Based on the first OCV-SOC curve point and the second OCV-SOC curve point, the real-time voltage difference corresponding to the current time point is determined. Based on the real-time voltage difference and the initial voltage difference corresponding to the hybrid battery at the time of manufacture, the SOH mapping relationship between the first battery pack and the second battery pack is determined. Compared to existing technologies that estimate the SOH value of lithium iron phosphate batteries through a mapping relationship, this application presents a linear relationship between the first OCV-SOC curve point and the second OCV-SOC curve point, with a large slope. Therefore, estimating the SOH value of lithium iron phosphate batteries using the SOH value of ternary lithium batteries can effectively improve the estimation accuracy of SOH values. Furthermore, it eliminates the need to obtain the SOC value of lithium iron phosphate batteries, solving the technical problem of low estimation accuracy of lithium iron phosphate battery health status in related technologies. This improves the accuracy of the correlation between the health status of lithium iron phosphate batteries and ternary lithium batteries, and the calibration method for the SOH mapping relationship is simple, thereby improving the estimation accuracy of lithium iron phosphate battery health status and reducing estimation costs.

[0056] In another embodiment, the process further includes determining the SOH mapping relationship between the first battery pack and the second battery pack before:

[0057] Step 1: Obtain the real-time charging amount of the first battery pack from the first peak point to the maximum dV / dQ curve point, and the initial charging amount of the hybrid battery when it leaves the factory;

[0058] Step 2: Determine the first SOH value of the first battery pack based on the real-time charging amount and the initial charging amount.

[0059] For example, before determining the SOH mapping relationship between the first battery pack and the second battery pack, it is first necessary to determine the first SOH value of the first battery pack. Since the SOC value of the first battery pack corresponding to the first peak point does not change with the SOH value of the first battery pack, i.e., the degree of aging, the first SOH value of the first battery pack can be obtained by acquiring the real-time charging amount of the first battery pack during the charging process from the SOC value of the first peak point to the maximum SOC value at the current time point, as well as the initial charging amount required when the first battery pack leaves the factory. This is the ratio of the real-time charging amount to the initial charging amount.

[0060] Specifically, the initial charge required for the first battery pack from the first peak point to full charge is ΔQ_LFP_BOL when it leaves the factory, while the real-time charge required at the current time point, i.e., after the first battery pack has aged, is ΔQ_LFP_Curr. Therefore, the first SOH value of the first battery pack can be calculated:

[0061]

[0062] In this embodiment, the first SOH value of the first battery pack is determined by the real-time charging amount required for the first battery pack to be fully charged from the first peak point and the initial charging amount. The method for determining the first SOH value is simple and the charging amount parameter is easy to obtain, thereby reducing the cost of obtaining the first SOH value.

[0063] In another embodiment, the process further includes determining the SOH mapping relationship between the first battery pack and the second battery pack before:

[0064] Step 1: Determine the current battery capacity of the second battery pack based on the real-time voltage difference of the second battery pack and the real-time charging amount of the first battery pack.

[0065] Step 2: Determine the initial battery capacity of the second battery pack based on the initial voltage difference of the second battery pack and the initial charge of the first battery pack.

[0066] Step 3: Determine the second SOH value of the second battery pack based on the current battery capacity and the initial battery capacity.

[0067] For example, the real-time voltage difference of the second battery pack and the real-time charging amount of the first battery pack are obtained respectively, and the current battery capacity of the second battery pack is calculated based on the real-time voltage difference and the real-time charging amount; the initial voltage difference of the second battery pack and the initial charging amount of the first battery pack are obtained respectively, and the initial battery capacity of the second battery pack is determined based on the initial voltage difference and the initial charging amount; finally, the second SOH value of the second battery pack is determined according to the ratio of the calculated current battery capacity of the second battery pack to the initial battery capacity.

[0068] Specifically, the curve segment between the first OCV-SOC curve point and the second OCV-SOC curve point of the second battery pack is considered to be linear, with a slope of K that does not change with the SOH of the second battery pack. When the hybrid battery pack is first manufactured, during the process of the first battery pack from the first peak point to full charge, the initial voltage difference between the first OCV-SOC curve point and the second OCV-SOC curve point of the second battery pack is ΔV_NCM_BOL. At the current time point, i.e., after the second battery pack has aged, the real-time voltage difference between the first OCV-SOC curve point and the second OCV-SOC curve point is ΔV_NCM_Curr. Therefore, the initial battery capacity of the second battery pack at the time of manufacture can be calculated as follows:

[0069]

[0070] The current battery capacity of the second battery pack is:

[0071]

[0072] Furthermore, the second SOH value of the second battery pack was obtained:

[0073]

[0074] In this embodiment, the current battery capacity and initial battery capacity of the second battery pack are determined based on the real-time voltage difference and the initial voltage difference, respectively, and then the second SOH value of the second battery pack is calculated. The calculation process is simple, thereby reducing the cost of obtaining the second SOH value.

[0075] In another embodiment, determining the SOH mapping relationship between the first battery pack and the second battery pack includes:

[0076] Based on the first SOH value and the second SOH value, the SOH mapping relationship between the first battery pack and the second battery pack is determined.

[0077] For example, after calculating the first SOH value and the second SOH value using the method in the above embodiments, the SOH mapping relationship between the first battery pack and the second battery pack is calculated using the ratio of the first SOH value and the second SOH value.

[0078] Specifically, by deriving the above formula, we obtain:

[0079]

[0080] Therefore, the SOH mapping relationship between the second battery pack and the first battery pack can be obtained as follows:

[0081] SOH_NCM=K_SOH_LFP2M*SOH_LFP

[0082]

[0083] Furthermore, the SOH mapping relationship between the first battery pack and the second battery pack can be obtained as follows:

[0084] SOH_LFP=K__2*_

[0085]

[0086] Specifically, as can be seen from the above SOH mapping formula, the SOH mapping relationship between the first battery pack and the second battery pack is only related to the ratio of the real-time voltage difference of the second battery pack to the initial voltage difference corresponding to the hybrid battery at the time of manufacture.

[0087] This embodiment directly establishes a mapping relationship between the first SOH value and the second SOH value. The process of establishing the mapping relationship is simple, thereby reducing the computational cost of the method for determining the SOH relationship of hybrid batteries.

[0088] In another embodiment, determining the SOH mapping relationship between the first battery pack and the second battery pack includes:

[0089] Step 1: Determine whether the real-time SOC value of the first battery pack increases from the SOC value corresponding to the first peak point to the maximum SOC value within a preset time period, and obtain the first determination result;

[0090] Step 2: Determine whether the rate of change of the slope of the OCV-SOC curve segment between the first OCV-SOC curve point and the second OCV-SOC curve point of the second battery pack is lower than a preset threshold, and obtain the second judgment result;

[0091] Step 3: If both the first and second judgment results meet the conditions, then determine the SOH mapping relationship between the first battery pack and the second battery pack.

[0092] For example, the premise that the first battery pack and the second battery pack can be mapped to each other is that the SOC range of the first battery pack from the first peak point to full charge corresponds to the linear change range of the OCV-SOC curve of the second battery pack (e.g., Figure 2 As shown in the figure, the reason is that the SOC value of the first battery pack corresponding to the first peak point and the slope of the linear change range of the second battery pack will not change with the aging of the hybrid battery.

[0093] For example, it is determined whether the real-time SOC value of the first battery pack increases from the SOC value corresponding to the first peak point to the maximum SOC value within a preset time period, and whether the rate of change of the slope of the OCV-SOC curve segment between the first OCV-SOC curve point and the second OCV-SOC curve point of the second battery pack is lower than a preset threshold (i.e., it can be regarded as a linear change relationship). If both conditions are met, the SOH mapping relationship between the first battery pack and the second battery pack is updated based on the method in this application. Specifically, the K_SOH_NCM2LFP coefficient and the K_SOH_LFP2NCM coefficient in the above embodiment are updated.

[0094] In this embodiment, two judgment conditions are set. The SOH relationship determination method in this application is activated only when both conditions are met, so as to obtain and update the SOH mapping relationship of the first battery pack and the second battery pack, thereby ensuring the accuracy of the parameters involved in the acquisition of the SOH mapping relationship and improving the accuracy of the SOH relationship of the hybrid battery.

[0095] In another embodiment, if at least one of the first judgment result and the second judgment result does not meet the condition, the second SOH value of the second battery pack is obtained, and the first SOH value of the first battery pack is determined based on the historical SOH mapping relationship between the first battery pack and the second battery pack.

[0096] For example, if at least one of the above two conditions is not met, the SOH relationship is not updated. Instead, the historically determined and saved SOH mapping relationship between the first battery pack and the second battery pack is directly obtained to determine the first SOH value of the first battery pack. This avoids determining the SOH relationship of the hybrid battery under inaccurate parameters, thereby improving the accuracy of the SOH relationship.

[0097] In another embodiment, the first battery pack includes a lithium iron phosphate battery pack, and the second battery pack includes a ternary lithium battery pack.

[0098] For example, in this embodiment, the first battery pack is set as a lithium iron phosphate battery pack and the second battery pack is set as a ternary lithium battery pack. The SOH value of the lithium iron phosphate battery pack is estimated by using the SOH mapping relationship between the lithium iron phosphate battery pack and the ternary lithium battery pack and the SOH value of the ternary lithium battery pack.

[0099] In this embodiment, the SOH value of the lithium iron phosphate battery pack is estimated by using the SOH value of the ternary lithium battery pack. By mapping the capacity health status of the ternary lithium battery to the capacity health status of the lithium iron phosphate battery, the accuracy of estimating the capacity health status of the lithium iron phosphate battery is improved.

[0100] It should be noted that the steps shown in the above process or in the flowchart of the accompanying figures can be executed in a computer system such as a set of computer-executable instructions, and 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.

[0101] This embodiment also provides a device for determining the state of harmonics (SOH) of a hybrid battery. This device is used to implement the above embodiments and preferred embodiments, and details already described will not be repeated. The terms "module," "unit," "subunit," etc., used below can refer to combinations of software and / or hardware that perform a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0102] Figure 4 This is a structural block diagram of the device for determining the SOH relationship of the hybrid battery in this embodiment, as shown below. Figure 4 As shown, the device includes:

[0103] The first determining module 10 is used to determine a first peak point based on the dV / dQ curve of the first battery pack. The first peak point is the peak point with the largest SOC value among multiple peak points of the dV / dQ curve.

[0104] The second determining module 20 is used to determine the corresponding first OCV-SOC curve point in the OCV-SOC curve of the second battery pack based on the first peak point of the first battery pack, and to determine the corresponding second OCV-SOC curve point in the OCV-SOC curve of the second battery pack based on the maximum dV / dQ curve point corresponding to the maximum SOC value of the first battery pack.

[0105] The third determining module 30 is used to determine the real-time voltage difference corresponding to the current time point based on the first OCV-SOC curve point and the second OCV-SOC curve point, and to determine the SOH mapping relationship between the first battery pack and the second battery pack based on the real-time voltage difference and the initial voltage difference corresponding to the hybrid battery at the time of manufacture.

[0106] The third determining module 30 is also used to determine whether the real-time SOC value of the first battery pack increases from the SOC value corresponding to the first peak point to the maximum SOC value within a preset time period, and to obtain the first determination result;

[0107] Determine whether the rate of change of the slope of the OCV-SOC curve segment between the first OCV-SOC curve point and the second OCV-SOC curve point of the second battery pack is lower than a preset threshold, and obtain a second determination result;

[0108] If both the first and second judgment results meet the conditions, then the SOH mapping relationship between the first battery pack and the second battery pack is determined.

[0109] The third determining module 30 is further configured to, if at least one of the first judgment result and the second judgment result does not meet the condition, obtain the second SOH value of the second battery pack, and determine the first SOH value of the first battery pack based on the historical SOH mapping relationship between the first battery pack and the second battery pack;

[0110] The device for determining the SOH relationship of a hybrid battery further includes a first SOH value determination module;

[0111] The first SOH value determination module is used to obtain the real-time charging amount of the current first battery pack from the first peak point to the maximum dV / dQ curve point, as well as the initial charging amount of the hybrid battery when it leaves the factory;

[0112] The first SOH value of the first battery pack is determined based on the real-time charging amount and the initial charging amount.

[0113] The device for determining the state of harmonics (SOH) of a hybrid battery further includes a second SOH value determination module;

[0114] The second SOH value determination module is used to determine the current battery capacity of the second battery pack based on the real-time voltage difference of the second battery pack and the real-time charging amount of the first battery pack.

[0115] The initial battery capacity of the second battery pack is determined based on the initial voltage difference of the second battery pack and the initial charge of the first battery pack.

[0116] Based on the current battery capacity and the initial battery capacity, determine the second SOH value of the second battery pack;

[0117] The device for determining the state of harmonic oxygen (SOH) relationship of a hybrid battery also includes an SOH mapping relationship determination module;

[0118] The SOH mapping relationship determination module is used to determine the SOH mapping relationship between the first battery pack and the second battery pack based on the first SOH value and the second SOH value.

[0119] It should be noted that the above modules can be functional modules or program modules, and can be implemented through software or hardware. For modules implemented through hardware, the above modules can reside in the same processor; or the above modules can be located in different processors in any combination.

[0120] This embodiment also provides an electronic device including a memory and a processor, the memory storing a computer program and the processor being configured to run the computer program to perform the steps in any of the above method embodiments.

[0121] Optionally, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor and the input / output device is connected to the processor.

[0122] Optionally, in this embodiment, the processor can be configured to perform the following steps via a computer program:

[0123] S1. Based on the dV / dQ curve of the first battery pack, determine the first peak point, which is the peak point with the largest SOC value among multiple peak points of the dV / dQ curve;

[0124] S2, based on the first peak point of the first battery pack, determine the corresponding first OCV-SOC curve point in the OCV-SOC curve of the second battery pack, and based on the maximum dV / dQ curve point corresponding to the maximum SOC value of the first battery pack, determine the corresponding second OCV-SOC curve point in the OCV-SOC curve of the second battery pack.

[0125] S3. Based on the first OCV-SOC curve point and the second OCV-SOC curve point, determine the real-time voltage difference corresponding to the current time point, and based on the real-time voltage difference and the initial voltage difference corresponding to the hybrid battery at the time of manufacture, determine the SOH mapping relationship between the first battery pack and the second battery pack.

[0126] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementations, and will not be repeated in this embodiment.

[0127] Furthermore, in conjunction with the method for determining the state of harmonics (SOH) of hybrid batteries provided in the above embodiments, this embodiment can also provide a storage medium for implementation. This storage medium stores a computer program; when executed by a processor, the computer program implements any of the SOH methods for determining hybrid batteries described in the above embodiments.

[0128] It should be understood that the specific embodiments described herein are merely illustrative of the application and not intended to limit it. All other embodiments derived by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0129] Obviously, the accompanying drawings are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar situations based on these drawings without any creative effort. Furthermore, it is understood that although the work done in this development process may be complex and lengthy, for those skilled in the art, certain design, manufacturing, or production modifications made based on the technical content disclosed in this application are merely conventional technical means and should not be considered as insufficient disclosure of this application.

[0130] The term "embodiment" in this application refers to a specific feature, structure, or characteristic described in connection with an embodiment that may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily imply the same embodiment, nor does it imply that it is mutually exclusive with or independent of other embodiments. It will be clearly or implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0131] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of patent protection. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A method for determining the state-ohm relationship of a hybrid battery, the hybrid battery comprising a first battery pack and a second battery pack, characterized in that, include: Based on the dV / dQ curve of the first battery pack, a first peak point is determined. The first peak point is the peak point with the largest SOC value among multiple peak points of the dV / dQ curve. Based on the first peak point of the first battery pack, the corresponding first OCV-SOC curve point is determined in the OCV-SOC curve of the second battery pack, and based on the maximum dV / dQ curve point corresponding to the maximum SOC value of the first battery pack, the corresponding second OCV-SOC curve point is determined in the OCV-SOC curve of the second battery pack. Based on the first OCV-SOC curve point and the second OCV-SOC curve point, the real-time voltage difference corresponding to the current time point is determined. Based on the real-time voltage difference and the initial voltage difference corresponding to the first OCV-SOC curve point and the second OCV-SOC curve point when the hybrid battery pack leaves the factory, the SOH mapping relationship between the first battery pack and the second battery pack is determined. The first battery pack includes a lithium iron phosphate battery pack, and the second battery pack includes a ternary lithium battery pack; Before determining the SOH mapping relationship between the first battery pack and the second battery pack, the following steps are also included: Get the real-time charge amount of the first battery pack from the first peak point to the maximum dV / dQ curve point, and the initial charge amount of the first battery pack from the first peak point to the maximum dV / dQ curve point when the hybrid battery leaves the factory; Based on the real-time charging amount and the initial charging amount, the first SOH value of the first battery pack is determined; Before determining the SOH mapping relationship between the first battery pack and the second battery pack, the following steps are also included: The current battery capacity of the second battery pack is determined based on the real-time voltage difference of the second battery pack and the real-time charging amount of the first battery pack. Based on the initial voltage difference of the second battery pack and the initial charge amount of the first battery pack, the initial battery capacity of the second battery pack at the time of manufacture is determined. Based on the current battery capacity and the initial battery capacity, determine the second SOH value of the second battery pack; Determining the SOH mapping relationship between the first battery pack and the second battery pack includes: Based on the first SOH value and the second SOH value, the SOH mapping relationship between the first battery pack and the second battery pack is determined; ,in, ΔQ_LFP_BOL is the first SOH value of the first battery pack, ΔQ_LFP_Curr is the initial charge amount, and ΔQ_LFP_Curr is the real-time charge amount. ,in, The initial battery capacity of the second battery pack at the time of manufacture is ΔV_NCM_BOL, the initial voltage difference is ΔV_NCM_BOL, and K is the slope of the curve segment between the first OCV-SOC curve point and the second OCV-SOC curve point of the second battery pack. ,in, This represents the current battery capacity of the second battery pack. The real-time charge level of the first battery pack. This represents the real-time voltage difference of the second battery pack. ,in, The second SOH value of the second battery pack; The SOH mapping relationship between the first battery pack and the second battery pack is as follows: ,in, .

2. The method for determining the SOH relationship of a hybrid battery according to claim 1, characterized in that, Determining the SOH mapping relationship between the first battery pack and the second battery pack includes: Determine whether the real-time SOC value of the first battery pack increases from the SOC value corresponding to the first peak point to the maximum SOC value within a preset time period, and obtain a first determination result; Determine whether the rate of change of the slope of the OCV-SOC curve segment between the first OCV-SOC curve point and the second OCV-SOC curve point of the second battery pack is lower than a preset threshold, and obtain a second determination result; If both the first and second judgment results meet the conditions, then the SOH mapping relationship between the first battery pack and the second battery pack is determined.

3. The method for determining the SOH relationship of a hybrid battery according to claim 2, characterized in that, If at least one of the first judgment result and the second judgment result does not meet the condition, then the second SOH value of the second battery pack is obtained, and the first SOH value of the first battery pack is determined based on the historical SOH mapping relationship between the first battery pack and the second battery pack.

4. A device for determining the state-of-the-art (SOH) relationship of a hybrid battery, the hybrid battery comprising a first battery pack and a second battery pack, characterized in that, include: The first determining module is used to determine a first peak point based on the dV / dQ curve of the first battery pack. The first peak point is the peak point with the largest SOC value among multiple peak points of the dV / dQ curve. The second determining module is used to determine the corresponding first OCV-SOC curve point in the OCV-SOC curve of the second battery pack based on the first peak point of the first battery pack, and to determine the corresponding second OCV-SOC curve point in the OCV-SOC curve of the second battery pack based on the maximum dV / dQ curve point corresponding to the maximum SOC value of the first battery pack. The third determining module is used to determine the real-time voltage difference corresponding to the current time point based on the first OCV-SOC curve point and the second OCV-SOC curve point, and to determine the SOH mapping relationship between the first battery pack and the second battery pack based on the real-time voltage difference and the initial voltage difference corresponding to the first OCV-SOC curve point and the second OCV-SOC curve point when the hybrid battery leaves the factory. The first battery pack includes a lithium iron phosphate battery pack, and the second battery pack includes a ternary lithium battery pack; Before determining the SOH mapping relationship between the first battery pack and the second battery pack, the following steps are also included: Get the real-time charge amount of the first battery pack from the first peak point to the maximum dV / dQ curve point, and the initial charge amount of the first battery pack from the first peak point to the maximum dV / dQ curve point when the hybrid battery leaves the factory; Based on the real-time charging amount and the initial charging amount, the first SOH value of the first battery pack is determined; Before determining the SOH mapping relationship between the first battery pack and the second battery pack, the following steps are also included: The current battery capacity of the second battery pack is determined based on the real-time voltage difference of the second battery pack and the real-time charging amount of the first battery pack. Based on the initial voltage difference of the second battery pack and the initial charge amount of the first battery pack, the initial battery capacity of the second battery pack at the time of manufacture is determined. Based on the current battery capacity and the initial battery capacity, determine the second SOH value of the second battery pack; Determining the SOH mapping relationship between the first battery pack and the second battery pack includes: Based on the first SOH value and the second SOH value, the SOH mapping relationship between the first battery pack and the second battery pack is determined; ,in, ΔQ_LFP_BOL is the first SOH value of the first battery pack, ΔQ_LFP_Curr is the initial charge amount, and ΔQ_LFP_Curr is the real-time charge amount. ,in, The initial battery capacity of the second battery pack at the time of manufacture is ΔV_NCM_BOL, the initial voltage difference is ΔV_NCM_BOL, and K is the slope of the curve segment between the first OCV-SOC curve point and the second OCV-SOC curve point of the second battery pack. ,in, This represents the current battery capacity of the second battery pack. The real-time charge level of the first battery pack. This represents the real-time voltage difference of the second battery pack. ,in, The second SOH value of the second battery pack; The SOH mapping relationship between the first battery pack and the second battery pack is as follows: ,in, .

5. An electronic device comprising a memory and a processor, characterized in that, The memory stores a computer program, and the processor is configured to run the computer program to perform the method for determining the SOH relationship of the hybrid battery according to any one of claims 1 to 3.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the method for determining the SOH relationship of the hybrid battery according to any one of claims 1 to 3.

Images