Battery direct current fast charging strategy determination method, device, equipment, medium and product

Abstract

The invention discloses a battery direct current fast charging strategy determination method and device, equipment, a medium and a product. The method comprises the following steps: in response to a fast charging current updating instruction for a to-be-tested battery cell in a use state, acquiring different battery temperatures of the to-be-tested battery cell in an initial state and initial fast charging currents of the to-be-tested battery cell in different charging states; determining the current fast charging current of the battery cell to be detected under different battery temperatures and different charging states; and according to the initial fast charging current and the current fast charging current, determining a direct current fast charging strategy of the battery cell to be tested at different battery temperatures and different charging states. According to the embodiment of the invention, the direct-current fast charging efficiency of the battery is improved, and the safety and reliability of command fast charging of the battery are improved.

Description

Technical Field

[0001] The present invention relates to the field of automobile testing technology, and in particular to a method, device, equipment, medium and product for determining a battery direct current fast charging strategy. Background Art

[0002] In recent years, power batteries, especially lithium-ion power batteries, have been widely used in passenger cars and commercial vehicles, and their market share has gradually increased. However, how to safely and effectively control the fast charging current has become an urgent problem to be solved in the automotive field.

[0003] The battery attenuation state caused by the use of battery cells will have a great impact on the fast charging current, but the existing battery fast charging strategy does not take the battery attenuation factor into consideration. Therefore, the existing battery DC fast charging strategy has low charging efficiency and there are more or less problems in the safety and reliability of the fast charging strategy. Summary of the invention

[0004] The present invention provides a method, device, equipment, medium and product for determining a battery DC fast charging strategy to improve the efficiency of battery DC fast charging, and improve the safety and reliability of battery command fast charging.

[0005] According to one aspect of the present invention, a method for determining a battery DC fast charging strategy is provided, the method comprising:

[0006] In response to a fast charge current update instruction for a battery cell to be tested in a use state, obtaining an initial fast charge current of the battery cell to be tested at different battery temperatures and different charging states in an initial state;

[0007] Determine the current fast charge current of the battery cell to be tested at different battery temperatures and different charging states;

[0008] The DC fast charging strategy of the battery cell to be tested under different battery temperatures and different charging states is determined according to the initial fast charging current and the current fast charging current.

[0009] According to another aspect of the present invention, a device for determining a battery DC fast charging strategy is provided, the device comprising:

[0010] An initial current acquisition module, configured to respond to a fast charge current update instruction for a battery cell to be tested in a use state, and acquire an initial fast charge current of the battery cell to be tested at different battery temperatures and different charge states in an initial state;

[0011] A current current determination module, used to determine the current fast charging current of the battery cell to be tested under different battery temperatures and different charging states;

[0012] The fast charging strategy determination module is used to determine the DC fast charging strategy of the battery cell to be tested under different battery temperatures and different charging states according to the initial fast charging current and the current fast charging current.

[0013] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:

[0014] at least one processor; and

[0015] a memory communicatively connected to the at least one processor; wherein,

[0016] The memory stores a computer program that can be executed by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the battery DC fast charging strategy determination method described in any embodiment of the present invention.

[0017] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the battery DC fast charging strategy determination method described in any embodiment of the present invention when executed.

[0018] According to another aspect of the present invention, a computer program product is provided, including a computer program, wherein when the computer program is executed by a processor, the method for determining a battery DC fast charging strategy according to any embodiment of the present invention is implemented.

[0019] The technical solution of the embodiment of the present invention obtains the initial fast charging current of the battery cell to be tested at different battery temperatures and different charging states in the initial state by responding to the fast charging current update instruction of the battery cell to be tested in the use state, and determines the current fast charging current of the battery cell to be tested at different battery temperatures and different charging states; and determines the DC fast charging strategy of the battery cell to be tested at different battery temperatures and different charging states according to the initial fast charging current and the current fast charging current. During the battery use stage, the above technical solution fully considers the fast charging influencing factors in the battery attenuation process, effectively integrates the change of polarization resistance into the fast charging strategy determination process, improves the battery DC fast charging efficiency, and improves the safety and reliability of battery instruction fast charging.

[0020] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 This is a flow chart of a method for determining a battery DC fast charging strategy provided in accordance with Embodiment 1 of the present invention;

[0023] Figure 2 This is a flow chart of a method for determining a battery DC fast charging strategy provided in accordance with Embodiment 2 of the present invention;

[0024] Figure 3 2 is a schematic diagram of the structure of a device for determining a battery DC fast charging strategy according to Embodiment 3 of the present invention;

[0025] Figure 4 It is a structural schematic diagram of an electronic device that implements the battery DC fast charging strategy determination method of an embodiment of the present invention. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0027] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0028] Embodiment 1

[0029] Figure 1This is a flow chart of a method for determining a battery DC fast charging strategy provided in the first embodiment of the present invention. This embodiment can be applied to the case where a suitable DC fast charging strategy is used to charge the battery under different vehicle driving conditions. The method can be executed by a battery DC fast charging strategy determination device, which can be implemented in the form of hardware and / or software, and can be configured in an electronic device. Figure 1 As shown, the method includes:

[0030] S110, in response to a fast charge current update instruction for the battery cell to be tested in use, obtaining an initial fast charge current of the battery cell to be tested at different battery temperatures and different charging states in an initial state.

[0031] S120: Determine the current fast charging current of the battery cell to be tested under different battery temperatures and different charging states.

[0032] S130: Determine a DC fast charging strategy for the battery cell to be tested under different battery temperatures and different charging states according to the initial fast charging current and the current fast charging current.

[0033] The battery cell to be tested in the use state may be a battery cell that has been put into use and is to be tested or formulated for an updated fast charging strategy. The fast charging current update instruction may be initiated by a relevant technician or by the driver, and may specifically be an instruction requesting an update of the optimal fast charging current.

[0034] It should be noted that the optimal charging rate of the battery is different at different temperatures and different SOCs (State of Charge). As the battery state decays during use, the optimal charging rate of the battery at different temperatures and different SOCs changes dynamically. Therefore, during the use of the battery, considering the impact of battery state decay and dynamically capturing the optimal charging rate of the battery at different temperatures and different SOCs can effectively improve the charging efficiency of the battery, as well as improve the safety and reliability of battery charging.

[0035] The initial state may be a state where the battery cell to be tested has not been put into use at the factory stage. The initial fast charging currents at different battery temperatures and different states of charge (SOC) under the initial state may be tested in advance and stored in the vehicle storage unit in advance for reference when DC fast charging is performed after the vehicle is put into use.

[0036] In an optional embodiment, the initial fast charge current of the battery cell to be tested at different battery temperatures and different charging states in the initial state is determined as follows:

[0037] Step a1: implanting a reference electrode into the cell structure of the battery cell to be tested in an initial state to obtain an initial battery cell of a three-electrode cell system.

[0038] Specifically, the cell structure of the battery cell to be tested in the initial state, that is, in the stage of leaving the factory but not being put into use, is structurally modified, and a reference electrode, such as a copper-plated lithium electrode, a nickel-plated lithium electrode, etc., is implanted to produce an initial battery cell with a three-electrode cell system with stable performance.

[0039] Step a2: performing a charge and discharge performance test on the initial battery cell to obtain an initial lithium deposition boundary current of the initial battery cell under different battery temperatures and different charge and discharge states.

[0040] The initial battery cells are subjected to constant current charge and discharge performance tests at different temperatures and different SOCs (or different voltages) to obtain the initial lithium precipitation boundary currents of the initial battery cells at different battery temperatures and different SOCs (charge and discharge states). It should be noted that the present embodiment uses the charge rate to characterize the lithium precipitation boundary current.

[0041] Exemplarily, for a temperature range of 5-10°C, the charge rate at an SOC value of 10% is adjusted from small to large to obtain a maximum charge rate when the negative pole is greater than 0V, and the maximum charge rate is used as the initial lithium deposition boundary current at 5-10°C and an SOC value of 10%.

[0042] The expression of the initial lithium plating boundary current of a battery cell under test at different temperatures and different SOCs can be seen in Table 1:

[0043] Table 1

[0044]

[0045] As can be seen from Table 1, the maximum charging rate (initial lithium deposition boundary current) obtained from the tests under different cell temperatures and different SOC states is different. Therefore, under different vehicle states, the charging rate corresponding to the corresponding state can be used for charging to improve charging efficiency; and charging can be carried out at a charging rate not greater than the corresponding state to improve charging safety and reliability.

[0046] Step a3: performing an online hybrid power pulse characteristic test on the initial battery cell to obtain an initial limiting current of the initial battery cell under different battery temperatures and different charge and discharge states.

[0047] It should be noted that the battery cell has its corresponding maximum operating temperature. When the maximum operating temperature is exceeded, the power battery is prone to thermal runaway or the battery capacity will decay rapidly. Therefore, the limiting current is the current of the battery cell at the highest allowable temperature.

[0048] Optionally, an online mixed power pulse characteristic test is performed on the initial battery cell to obtain an initial limiting current of the initial battery cell at different battery temperatures and different charge and discharge states, including:

[0049] Step a31, performing an online mixed power pulse characteristic test on the initial battery cell to determine the initial ohmic resistance and initial polarization resistance of the initial battery cell at different battery temperatures and different charging states.

[0050] Among them, the online hybrid power pulse characteristic test is the HPPC (Hybrid Pulse Power Characterization) test.

[0051] Specifically, ensure that the initial battery cells of the three-electrode battery system are in a fully charged or discharged state before the test and that the battery remains balanced and stable. Set the pulse parameters, which may specifically include pulse amplitude, duration, and interval time. For example, a 10-second charge and discharge pulse is applied, followed by a 20-second static rest. During each pulse, voltage data, current data, SOC, temperature and other data can be recorded in real time. Repeat the above pulse test under different SOC levels and temperature conditions to obtain more comprehensive performance data. Extract the initial polarization resistance and initial ohmic resistance from the pulse test.

[0052] Step a32, obtaining initial cell parameters of the initial battery cells.

[0053] The initial cell parameters may include the cell's own structural parameters, heat transfer parameters, and electric capacity, etc. For example, the cell's own structural parameters may include the cell's volume and the cell's material, etc.; the heat transfer parameters may include thermal conductivity and specific heat capacity parameters, etc. The initial cell parameters may be measured in advance or obtained based on relevant literature records.

[0054] Step a33: construct an initial equivalent circuit electrothermal model according to the initial ohmic resistance and the initial polarization resistance and based on the initial battery cell parameters.

[0055] The equivalent circuit model structure may be an RC circuit model and a Thevenin model. Specifically, according to the selected equivalent circuit model structure, an initial equivalent circuit electrothermal model is constructed based on initial ohmic resistance, initial polarization resistance and initial cell parameters.

[0056] Step a34: determining the initial limiting current of the initial battery cell at different battery temperatures and different charging states according to the initial equivalent circuit electrothermal model.

[0057] Specifically, the initial equivalent circuit electrothermal model is used to calculate the initial limiting current of the initial battery cell at different temperatures and different charging states.

[0058] Step a4: Determine the initial fast charge current of the battery cell to be tested at different battery temperatures and different charging states in the initial state according to the initial limiting current and the initial lithium plating boundary current.

[0059] For any initial limiting current and initial lithium deposition boundary current at the same battery temperature and the same charging state, select the smaller current value as the initial fast charge current. For example, for a battery temperature of 5-10°C and a SOC of 10%, the initial limiting current is 1.3C and the initial lithium deposition boundary current is 1.5C, then the initial fast charge current is determined to be 1.3C when the battery temperature is 5-10°C and the SOC is 10%.

[0060] The above technical solution improves the accuracy and reliability of the fast charging current determination by modifying the cell structure of the battery cell to be tested, implanting a reference electrode, and determining the optimal fast charging current for the modified three-electrode cell system under different battery temperatures and different charging and discharging conditions, thereby providing an accurate reference for the subsequent fast charging current update.

[0061] Determine the current fast charge current of the battery cell under test at different battery temperatures and different charging states. It should be noted that due to the capacity decay of the battery cell during use, the optimal initial fast charge current for reference under different charge and discharge states will change accordingly. Therefore, it is necessary to regularly update the optimal fast charge current to accurately obtain the DC fast charge strategy under different states.

[0062] In an optional embodiment, determining the current fast charging current of the battery cell to be tested at different battery temperatures and different charging states includes:

[0063] Step b1, determining the current ohmic resistance and current polarization resistance of the battery cell to be tested at different battery temperatures and different charging states.

[0064] The current ohmic resistance and the current polarization resistance are specifically the resistance values ​​of the battery cell after it is put into use.

[0065] Optionally, determining the current ohmic resistance and current polarization resistance of the battery cell to be tested at different battery temperatures and different charging states includes: performing an online mixed power pulse characteristic test on the battery cell to be tested to determine the current ohmic resistance and current polarization resistance of the battery cell to be tested at different battery temperatures and different charging states.

[0066] Specifically, during the use of the battery, an online hybrid power pulse characteristic test (HPPC) is performed on the battery cell to obtain the current ohmic resistance and current polarization resistance of the battery cell under test at different battery temperatures and different charging states in the current time period.

[0067] Step b2: determining the current fast charging current of the battery cell to be tested under different battery temperatures and different charging states according to the current ohmic resistance and the current polarization resistance.

[0068] In an optional embodiment, determining the current fast charging current of the battery cell to be tested at different battery temperatures and different charging states according to the current ohmic resistance and the current polarization resistance includes:

[0069] Step b21: determining the current limiting current of the battery cell to be tested at different battery temperatures and different charging states according to the current ohmic resistance and the current polarization resistance.

[0070] The current limiting current may be the current of the battery cell at the maximum allowable temperature in the current time period.

[0071] Optionally, the current limiting current of the battery cell to be tested at different battery temperatures and different charging states is determined according to the current ohmic resistance and the current polarization resistance, including: obtaining cell-related parameters of the battery cell to be tested; constructing a current equivalent circuit electrothermal model based on the cell-related parameters according to the current ohmic resistance and the current polarization resistance; and determining the current limiting current of the battery cell to be tested at different battery temperatures and different charging states according to the current equivalent circuit electrothermal model.

[0072] Among them, the cell-related parameters may include the cell's own structural parameters, heat transfer parameters, and electric capacity, etc. For example, the cell's own structural parameters may include the cell's volume and the cell's material, etc.; the heat transfer parameters may include thermal conductivity and specific heat capacity parameters, etc. The initial cell parameters may be measured in advance or obtained based on relevant literature records.

[0073] According to the current ohmic resistance, current polarization resistance and related parameters of the battery cell, the current equivalent circuit electrothermal model is constructed based on the pre-selected equivalent circuit model structure. The current equivalent circuit electrothermal model is used to determine the current limiting current of the battery under test at different battery temperatures and different charging states in the current time period.

[0074] Step b2: determining the current lithium deposition boundary current of the battery cell to be tested at different battery temperatures and different charging states according to the current polarization resistance.

[0075] It should be noted that since the polarization resistance of the negative electrode of the battery cell is much greater than that of the positive electrode, the overall polarization resistance of the battery cell can be regarded as the polarization resistance of the negative electrode. After approximate replacement, the boundary condition for no lithium deposition in the battery cell can be expressed as:

[0076] U n,ocv >-i ct R ct >0;

[0077] Among them, Un,ocv is the equilibrium point of the graphite negative electrode, which is a fixed value in a certain battery system; R ct is the current polarization resistance of the cell, obtained through the above HPPC experiment; i ct is the current lithium plating boundary current. As the battery ages during use, the current polarization resistance R ct The value of will increase accordingly, and accordingly, the lithium deposition boundary current will decrease.

[0078] Step b3: determine the current fast charging current of the battery cell to be tested under different battery temperatures and different charging states according to the current limiting current and the current lithium plating boundary current.

[0079] For any current limiting current and current lithium deposition boundary current at the same battery temperature and the same charging state, select the smaller current value as the current fast charging current. For example, for a battery temperature of 5-10°C and a SOC of 10%, the current limiting current is 1.3C and the current lithium deposition boundary current is 1.5C, then the current fast charging current is determined to be 1.3C when the battery temperature is 5-10°C and the SOC is 10%.

[0080] According to the initial fast charging current and the current fast charging current, the DC fast charging strategy of the battery cell to be tested under different battery temperatures and different charging states is determined.

[0081] Among them, the DC fast charging strategy can specifically be what kind of fast charging current is used at a certain temperature and SOC state to ensure that the charging efficiency in this state is faster, or safer and more reliable.

[0082] In an optional embodiment, the DC fast charging strategy of the battery cell to be tested at different battery temperatures and different charging states is determined based on the initial fast charging current and the current fast charging current, including: comparing the initial fast charging current and the current fast charging current at the same battery temperature and the same charging and discharging state to obtain a target fast charging current with a smaller current, and using the target fast charging current as the DC fast charging strategy at the corresponding battery temperature and the corresponding charging and discharging state.

[0083] For any initial fast charge current and current fast charge current at the same battery temperature and the same discharge state, the two fast charge currents are compared, and the smaller current is determined as the target fast charge current. The DC fast charge strategy at the battery temperature and discharge state is to charge the battery with the target fast charge current.

[0084] The technical solution of the embodiment of the present invention obtains the initial fast charging current of the battery cell to be tested at different battery temperatures and different charging states in the initial state by responding to the fast charging current update instruction of the battery cell to be tested in the use state, and determines the current fast charging current of the battery cell to be tested at different battery temperatures and different charging states; and determines the DC fast charging strategy of the battery cell to be tested at different battery temperatures and different charging states according to the initial fast charging current and the current fast charging current. During the battery use stage, the above technical solution fully considers the fast charging influencing factors in the battery attenuation process, effectively integrates the change of polarization resistance into the fast charging strategy determination process, improves the battery DC fast charging efficiency, and improves the safety and reliability of battery instruction fast charging.

[0085] Embodiment 2

[0086] Figure 2 This is a flow chart of a method for determining a battery DC fast charging strategy provided in Embodiment 2 of the present invention. This embodiment provides a preferred example based on the above embodiment.

[0087] like Figure 2 As shown, the method comprises the following specific steps:

[0088] S21. Implanting a reference electrode into the cell structure of the battery cell to be tested in an initial state to obtain an initial battery cell of a three-electrode cell system.

[0089] S22. Perform a charge and discharge performance test on the initial battery cell to obtain an initial lithium deposition boundary current of the initial battery cell under different battery temperatures and different charge and discharge states.

[0090] S23, performing an online mixed power pulse characteristic test on the initial battery cell to obtain an initial limiting current of the initial battery cell under different battery temperatures and different charge and discharge states.

[0091] Specifically, an online mixed power pulse characteristic test is performed on the initial battery cell to determine the initial ohmic resistance and initial polarization resistance of the initial battery cell at different battery temperatures and different charging states; the initial cell parameters of the initial battery cell are obtained; according to the initial ohmic resistance and the initial polarization resistance, based on the initial cell parameters, an initial equivalent circuit electrothermal model is constructed; according to the initial equivalent circuit electrothermal model, an initial limiting current of the initial battery cell at the different battery temperatures and different charging states is determined.

[0092] S24. Determine the initial fast charge current of the battery cell to be tested at different battery temperatures in the initial state and at different charging states according to the initial limiting current and the initial lithium plating boundary current.

[0093] S25. In response to a fast charge current update instruction for the battery cell to be tested in use, obtain an initial fast charge current of the battery cell to be tested at different battery temperatures and different charging states in an initial state.

[0094] S26, performing an online mixed power pulse characteristic test on the battery cell to be tested, and determining the current ohmic resistance and current polarization resistance of the battery cell to be tested under different battery temperatures and different charging states.

[0095] S27. Determine the current limiting current of the battery cell to be tested under different battery temperatures and different charging states according to the current ohmic resistance and the current polarization resistance.

[0096] Specifically, the cell-related parameters of the battery cell to be tested are obtained; according to the current ohmic resistance and the current polarization resistance, based on the cell-related parameters, a current equivalent circuit electrothermal model is constructed; according to the current equivalent circuit electrothermal model, the current limiting current of the battery cell to be tested under different battery temperatures and different charging states is determined.

[0097] S28. Determine the current lithium deposition boundary current of the battery cell to be tested at different battery temperatures and different charging states according to the current polarization resistance.

[0098] S29. Determine the current fast charging current of the battery cell to be tested under different battery temperatures and different charging states according to the current limiting current and the current lithium plating boundary current.

[0099] S210. Compare the initial fast charge current and the current fast charge current at the same battery temperature and the same charge and discharge state to obtain a target fast charge current with a smaller current, and use the target fast charge current as the DC fast charge strategy at the corresponding battery temperature and the corresponding charge and discharge state.

[0100] Embodiment 3

[0101] Figure 3 A schematic diagram of the structure of a battery DC fast charging strategy determination device provided in the third embodiment of the present invention. A battery DC fast charging strategy determination device provided in the embodiment of the present invention can be applied to the situation where a suitable DC fast charging strategy is adopted to charge the battery under different vehicle driving conditions. The battery DC fast charging strategy determination device can be implemented in the form of hardware and / or software, such as Figure 3 As shown, the device specifically includes: an initial current acquisition module 301, a current current determination module 302 and a current current determination module 303. Among them,

[0102] The initial current acquisition module 301 is used to respond to the fast charge current update instruction of the battery cell to be tested in the use state, and obtain the initial fast charge current of the battery cell to be tested under different battery temperatures and different charging states in the initial state;

[0103] A current current determination module 302 is used to determine the current fast charging current of the battery cell to be tested under different battery temperatures and different charging states;

[0104] The fast charging strategy determination module 303 is used to determine the DC fast charging strategy of the battery cell to be tested under different battery temperatures and different charging states according to the initial fast charging current and the current fast charging current.

[0105] The technical solution of the embodiment of the present invention obtains the initial fast charging current of the battery cell to be tested at different battery temperatures and different charging states in the initial state by responding to the fast charging current update instruction of the battery cell to be tested in the use state, and determines the current fast charging current of the battery cell to be tested at different battery temperatures and different charging states; and determines the DC fast charging strategy of the battery cell to be tested at different battery temperatures and different charging states according to the initial fast charging current and the current fast charging current. During the battery use stage, the above technical solution fully considers the fast charging influencing factors in the battery attenuation process, effectively integrates the change of polarization resistance into the fast charging strategy determination process, improves the battery DC fast charging efficiency, and improves the safety and reliability of battery instruction fast charging.

[0106] Optionally, the current determining module 302 includes:

[0107] a current resistance determination unit, used to determine the current ohmic resistance and current polarization resistance of the battery cell to be tested at the different battery temperatures and different charging states;

[0108] The current determining unit is used to determine the current fast charging current of the battery cell to be tested under different battery temperatures and different charging states according to the current ohmic resistance and the current polarization resistance.

[0109] Optionally, the current determining unit comprises:

[0110] a current limiting current determining subunit, used for determining the current limiting current of the battery cell to be tested under different battery temperatures and different charging states according to the current ohmic resistance and the current polarization resistance;

[0111] A current lithium deposition current determination subunit, used to determine the current lithium deposition boundary current of the battery cell to be tested under different battery temperatures and different charging states according to the current polarization resistance;

[0112] The current current determination subunit is used to determine the current fast charging current of the battery cell to be tested under different battery temperatures and different charging states according to the current limiting current and the current lithium plating boundary current.

[0113] Optionally, the current limiting current determining subunit is specifically used for:

[0114] Obtaining cell-related parameters of the battery cell to be tested;

[0115] According to the current ohmic resistance and the current polarization resistance, based on the battery cell related parameters, construct a current equivalent circuit electrothermal model;

[0116] The current limiting current of the battery cell to be tested under different battery temperatures and different charging states is determined according to the current equivalent circuit electrothermal model.

[0117] Optionally, the current resistance determination unit is specifically used to:

[0118] An online mixed power pulse characteristic test is performed on the battery cell to be tested to determine the current ohmic resistance and current polarization resistance of the battery cell to be tested under the different battery temperatures and different charging states.

[0119] Optionally, the fast charging strategy determination module 303 is specifically used to:

[0120] The initial fast charge current and the current fast charge current under the same battery temperature and the same charge and discharge state are compared to obtain a target fast charge current with a smaller current, and the target fast charge current is used as the DC fast charge strategy under the corresponding battery temperature and the corresponding charge and discharge state.

[0121] Optionally, the device further includes: an initial current determination module, used to determine the initial fast charge current of the battery cell to be tested at different battery temperatures and different charging states in the initial state; accordingly, the initial current determination module includes:

[0122] An initial cell generating unit, used for implanting a reference electrode into the cell structure of the battery cell to be tested in an initial state, to obtain an initial battery cell of a three-electrode cell system;

[0123] A charge and discharge performance testing unit, used to perform a charge and discharge performance test on the initial battery cell to obtain an initial lithium precipitation boundary current of the initial battery cell under the different battery temperatures and different charge and discharge states;

[0124] A pulse performance testing unit, used for performing an online hybrid power pulse characteristic test on the initial battery cell to obtain an initial limiting current of the initial battery cell under the different battery temperatures and different charge and discharge states;

[0125] The initial current determination unit is used to determine the initial fast charging current of the battery cell to be tested under different battery temperatures and different charging states in the initial state according to the initial limiting current and the initial lithium plating boundary current.

[0126] Optional, pulse performance test unit, specifically used for:

[0127] Performing an online mixed power pulse characteristic test on the initial battery cell to determine the initial ohmic resistance and initial polarization resistance of the initial battery cell at the different battery temperatures and different charging states;

[0128] Obtaining initial cell parameters of the initial battery cell;

[0129] According to the initial ohmic resistance and the initial polarization resistance, based on the initial battery cell parameters, construct an initial equivalent circuit electrothermal model;

[0130] The initial limiting current of the initial battery cell at the different battery temperatures and different charging states is determined according to the initial equivalent circuit electrothermal model.

[0131] The battery DC fast charging strategy determination device provided in the embodiment of the present invention can execute the battery DC fast charging strategy determination method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0132] Embodiment 4

[0133] Figure 4 A schematic diagram of the structure of an electronic device 40 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0134] like Figure 4 As shown, the electronic device 40 includes at least one processor 41, and a memory connected to the at least one processor 41, such as a read-only memory (ROM) 42, a random access memory (RAM) 43, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 41 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 42 or the computer program loaded from the storage unit 48 to the random access memory (RAM) 43. In the RAM 43, various programs and data required for the operation of the electronic device 40 can also be stored. The processor 41, the ROM 42, and the RAM 43 are connected to each other through a bus 44. An input / output (I / O) interface 45 is also connected to the bus 44.

[0135] A number of components in the electronic device 40 are connected to the I / O interface 45, including: an input unit 46, such as a keyboard, a mouse, etc.; an output unit 47, such as various types of displays, speakers, etc.; a storage unit 48, such as a disk, an optical disk, etc.; and a communication unit 49, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 49 allows the electronic device 40 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0136] The processor 41 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 41 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The processor 41 executes the various methods and processes described above, such as a method for determining a battery DC fast charging strategy.

[0137] In some embodiments, the battery DC fast charging strategy determination method may be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 48. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 40 via the ROM 42 and / or the communication unit 49. When the computer program is loaded into the RAM 43 and executed by the processor 41, one or more steps of the battery DC fast charging strategy determination method described above may be performed. Alternatively, in other embodiments, the processor 41 may be configured to execute the battery DC fast charging strategy determination method in any other appropriate manner (e.g., by means of firmware).

[0138] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0139] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0140] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0141] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0142] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0143] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0144] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0145] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for determining a battery DC fast charging strategy, characterized in that: include: In response to a fast charge current update instruction for a battery cell to be tested in a use state, obtaining an initial fast charge current of the battery cell to be tested at different battery temperatures and different charging states in an initial state; Determine the current fast charge current of the battery cell to be tested at different battery temperatures and different charging states; The DC fast charging strategy of the battery cell to be tested under different battery temperatures and different charging states is determined according to the initial fast charging current and the current fast charging current.

2. The method according to claim 1, characterized in that The determining the current fast charging current of the battery cell to be tested under different battery temperatures and different charging states includes: Determine the current ohmic resistance and current polarization resistance of the battery cell to be tested at the different battery temperatures and different charging states; The current fast charging current of the battery cell to be tested under different battery temperatures and different charging states is determined according to the current ohmic resistance and the current polarization resistance.

3. The method according to claim 2, characterized in that The determining, according to the current ohmic resistance and the current polarization resistance, the current fast charging current of the battery cell to be tested at different battery temperatures and different charging states comprises: Determining, according to the current ohmic resistance and the current polarization resistance, a current limiting current of the battery cell to be tested at different battery temperatures and different charging states; Determining the current lithium deposition boundary current of the battery cell to be tested at different battery temperatures and different charging states according to the current polarization resistance; The current fast charging current of the battery cell to be tested under different battery temperatures and different charging states is determined according to the current limiting current and the current lithium plating boundary current.

4. The method according to claim 3, characterized in that The determining, according to the current ohmic resistance and the current polarization resistance, the current limiting current of the battery cell to be tested at different battery temperatures and different charging states comprises: Obtaining cell-related parameters of the battery cell to be tested; According to the current ohmic resistance and the current polarization resistance, based on the battery cell related parameters, construct a current equivalent circuit electrothermal model; The current limiting current of the battery cell to be tested under different battery temperatures and different charging states is determined according to the current equivalent circuit electrothermal model.

5. The method according to claim 2, characterized in that: The determining the current ohmic resistance and the current polarization resistance of the battery cell to be tested at the different battery temperatures and different charging states comprises: An online mixed power pulse characteristic test is performed on the battery cell to be tested to determine the current ohmic resistance and current polarization resistance of the battery cell to be tested under the different battery temperatures and different charging states.

6. The method according to claim 1, characterized in that The determining, according to the initial fast charging current and the current fast charging current, a DC fast charging strategy of the battery cell to be tested under different battery temperatures and different charging states comprises: The initial fast charge current and the current fast charge current under the same battery temperature and the same charge and discharge state are compared to obtain a target fast charge current with a smaller current, and the target fast charge current is used as the DC fast charge strategy under the corresponding battery temperature and the corresponding charge and discharge state.

7. The method according to claim 1, characterized in that The initial fast charge current of the battery cell to be tested at different battery temperatures in the initial state and at different charging states is determined as follows: Implanting a reference electrode into the cell structure of the battery cell to be tested in an initial state to obtain an initial battery cell of a three-electrode cell system; Performing a charge and discharge performance test on the initial battery cell to obtain an initial lithium precipitation boundary current of the initial battery cell under the different battery temperatures and different charge and discharge states; Performing an online hybrid power pulse characteristic test on the initial battery cell to obtain an initial limiting current of the initial battery cell under the different battery temperatures and different charge and discharge states; According to the initial limiting current and the initial lithium plating boundary current, the initial fast charging current of the battery cell to be tested under different battery temperatures and different charging states in the initial state is determined.

8. The method according to claim 7, characterized in that The performing an online hybrid power pulse characteristic test on the initial battery cell to obtain an initial limiting current of the initial battery cell under the different battery temperatures and different charge and discharge states includes: Performing an online mixed power pulse characteristic test on the initial battery cell to determine the initial ohmic resistance and initial polarization resistance of the initial battery cell at the different battery temperatures and different charging states; Obtaining initial cell parameters of the initial battery cell; According to the initial ohmic resistance and the initial polarization resistance, based on the initial battery cell parameters, construct an initial equivalent circuit electrothermal model; The initial limiting current of the initial battery cell at the different battery temperatures and different charging states is determined according to the initial equivalent circuit electrothermal model.

9. A device for determining a battery DC fast charging strategy, characterized in that: include: An initial current acquisition module, configured to respond to a fast charge current update instruction for a battery cell to be tested in a use state, and acquire an initial fast charge current of the battery cell to be tested at different battery temperatures and different charge states in an initial state; A current current determination module, used to determine the current fast charging current of the battery cell to be tested under different battery temperatures and different charging states; The fast charging strategy determination module is used to determine the DC fast charging strategy of the battery cell to be tested under different battery temperatures and different charging states according to the initial fast charging current and the current fast charging current.

10. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the battery DC fast charging strategy determination method described in any one of claims 1-8.

11. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the battery DC fast charging strategy determination method described in any one of claims 1-8 when executed.

12. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is executed by a processor, the method for determining a battery DC fast charging strategy according to any one of claims 1 to 8 is implemented.

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