Method for battery recharge, battery management system, battery system and power consuming device

Abstract

This application provides a battery recharge method, a battery management system, a battery system, and an electrical device that can reduce the possibility of battery overvoltage. The method includes: obtaining a target SOC of the battery, wherein before the battery reaches the target SOC, the battery voltage increases with increasing SOC, and during a certain period after the battery reaches the target SOC, the battery voltage decreases with increasing SOC; determining a target allowable recharge power for the battery based on the target SOC; and controlling the battery recharge based on the target allowable recharge power.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a method for recharging a battery, a battery management system, a battery system, and an electrical device. Background Technology

[0002] With the increasing severity of energy shortages and other problems in modern society, electric vehicles, as a new energy vehicle, have received widespread attention since their introduction. For electric vehicles, battery technology is a crucial factor in their development.

[0003] Overvoltage issues must be avoided as much as possible during battery recharging. Therefore, reducing the possibility of battery overvoltage is an urgent problem to be solved. Summary of the Invention

[0004] This application provides a method for battery recharging, a battery management system, a battery system, and an electrical device, which can reduce the possibility of battery overvoltage.

[0005] In a first aspect, a method for battery recharge is provided, the method comprising: obtaining a target state of charge (SOC) of the battery, wherein, before the battery reaches the target SOC, the voltage of the battery increases with the increase of the battery SOC, and during a certain period of time after the battery reaches the target SOC, the voltage of the battery decreases with the increase of the battery SOC; determining a target allowable recharge power of the battery based on the target SOC; recharging the battery based on the target allowable recharge power, and controlling the battery recharge with the target allowable recharge power.

[0006] Before the battery reaches the target SOC, the battery voltage increases with increasing SOC. However, during a certain period after reaching the target SOC, the battery voltage decreases with increasing SOC, resulting in a sudden drop in the battery's charging voltage curve. It can be seen that the target SOC is an inflection point. Therefore, this embodiment determines the target allowable recharge power of the battery based on the target SOC, ensuring that the determined target allowable recharge power is adapted to the battery's characteristics. By controlling the battery's recharge using this target allowable recharge power, the possibility of battery overvoltage can be effectively reduced.

[0007] In some possible implementations, the method further includes: obtaining the maximum allowable recharge power of the battery and the current state of charge (SOC); determining the target allowable recharge power of the battery based on the target SOC includes: determining the target allowable recharge power based on the target SOC, the current SOC, and the maximum allowable recharge power.

[0008] In addition to the target SOC, this technical solution also determines the target allowable recharge power based on the maximum allowable recharge power and the battery's current SOC. That is, it determines the target allowable recharge power based on more parameters. In this way, the accuracy of the target allowable recharge power is higher, which can further reduce the problem of overvoltage in the battery during recharge.

[0009] In some possible implementations, determining the target allowable recharge power based on the target SOC, the current SOC, and the maximum allowable recharge power includes: obtaining the battery voltage when the current SOC is less than or equal to the target SOC; and determining the target allowable recharge power of the battery based on the battery voltage and the maximum allowable recharge power.

[0010] In addition to the target SOC, the current SOC, and the maximum allowable recharge power, this technical solution also determines the target allowable recharge power based on the battery voltage. That is, it determines the target allowable recharge power based on more parameters, which makes the accuracy of the determined target allowable recharge power higher, thereby further reducing the problem of overvoltage in the battery during recharge.

[0011] In some possible implementations, determining the target allowable recharge power of the battery based on the battery voltage and the maximum allowable recharge power includes: if the battery voltage is greater than or equal to a first preset voltage, reducing the maximum allowable recharge power, and the power obtained after reducing the maximum allowable recharge power is the target allowable recharge power; if the battery voltage is less than or equal to a second preset voltage, determining the maximum allowable recharge power as the target allowable recharge power.

[0012] If the battery voltage is greater than or equal to the first preset voltage, it indicates that the battery voltage is too high. At this time, the maximum allowable recharge power is reduced, and the power obtained by reducing the maximum allowable recharge power is determined as the target allowable recharge power. This reduces the actual recharge power of the battery, thereby reducing the possibility of battery overvoltage.

[0013] If the battery voltage is less than the second preset voltage, it indicates that the battery voltage is low at this time, and the possibility of overvoltage is low. Therefore, setting the maximum allowable recharge power as the target allowable recharge power can effectively improve the efficiency of battery recharge.

[0014] In some possible implementations, the first preset voltage is the difference between the full charge cutoff voltage of the battery and a first voltage, and the second preset voltage is the difference between the full charge cutoff voltage and a second voltage.

[0015] This technical solution sets the first preset voltage to the difference between the full-charge cutoff voltage and the first voltage. This means that power limiting is implemented before the battery voltage reaches the full-charge cutoff voltage, thus reducing the maximum allowable recharge power and lowering the probability of overvoltage. Furthermore, setting the second preset voltage to the difference between the full-charge cutoff voltage and the second voltage reduces overvoltage caused by further increases in the battery's polarization voltage. It also reduces the formation of substances like sodium dendrites to some extent, effectively improving battery performance.

[0016] In some possible implementations, the second voltage is greater than the first voltage. Setting the second voltage to be greater than the first voltage, i.e., having an interval between the first and second voltages, can reduce the likelihood of the battery repeatedly triggering the power limiting strategy, thereby improving recharge efficiency.

[0017] In some possible implementations, determining the target allowable recharge power based on the target SOC, the current SOC, and the maximum allowable recharge power includes: if the current SOC is greater than the target SOC, reducing the maximum allowable recharge power, and the power obtained after reducing the maximum allowable recharge power is the target allowable recharge power.

[0018] This technical solution, when the actual SOC of the battery is greater than the target SOC, uniformly limits the maximum allowable recharge power, reduces the amount of computation, improves the efficiency of determining the target allowable recharge power, and thus improves the efficiency of battery recharge.

[0019] In some possible implementations, the method further includes: during the recharging of the battery at the target allowable recharging power, acquiring the battery voltage and the current state of charge (SOC) of the battery during the recharging process; if the current SOC drops below the target SOC and the battery voltage is less than or equal to a second preset voltage, adjusting the target allowable recharging power to the maximum allowable recharging power.

[0020] This technical solution addresses the issue that when the battery voltage drops to less than or equal to a second preset voltage, and the current state of charge (SOC) decreases below the target SOC, it indicates that the battery is less likely to experience overvoltage. In this case, restoring the maximum allowable recharge power allows the battery to recharge at the maximum allowable recharge power, thereby improving the battery's recharge efficiency.

[0021] In some possible implementations, the second preset voltage is the difference between the battery's full charge cutoff voltage and the second voltage.

[0022] In some possible implementations, reducing the maximum allowable recharge power to obtain the target allowable recharge power includes: determining a target adjustment value based on the battery voltage of the battery and based on multiple correspondences between voltage and power adjustment values; and reducing the maximum allowable recharge power by the target adjustment value to obtain the target allowable recharge power.

[0023] This technical solution establishes multiple correspondences between voltage and power adjustment values, enabling step-by-step power control and more precise power adjustment. This not only ensures recharge efficiency but also effectively reduces the possibility of battery overvoltage.

[0024] In some possible implementations, the battery includes a sodium-ion battery. Sodium-ion batteries have good low-temperature performance, maintaining a high capacity retention rate even in cold environments. Therefore, including a sodium-ion battery allows the electrical device to operate normally in low-temperature environments without needing to preheat the battery before driving.

[0025] In a second aspect, a battery management system is provided, comprising: a control unit, configured to acquire a target SOC of the battery, wherein, before the battery reaches the target SOC, the voltage of the battery increases with the increase of the battery SOC, and during a certain period of time after the battery reaches the target SOC, the voltage of the battery decreases with the increase of the battery SOC; the control unit is further configured to determine a target allowable recharge power of the battery based on the target SOC, and control the recharge of the battery with the target allowable recharge power.

[0026] Thirdly, a battery management system is provided, including a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call the computer program to execute the methods in the first aspect or its various implementations.

[0027] Fourthly, a battery system is provided, comprising: a battery, wherein the voltage of the battery increases with increasing SOC before the battery reaches a target SOC, and the voltage of the battery decreases with increasing SOC for a portion of a time after the battery reaches the target SOC; and a battery management system for performing the methods of the first aspect or its implementations described above.

[0028] Fifthly, a battery system is provided, including a first battery, a second battery, and a battery management system. The battery system includes multiple independently configured energy zones, with the first battery and the second battery respectively disposed in different energy zones of the multiple energy zones. Specifically, before the first battery reaches a first target SOC, the voltage of the first battery increases with the increase of its SOC; during a certain period after the first battery reaches the first target SOC, the voltage of the first battery decreases with the increase of its SOC. The battery management system is used to acquire the first target SOC of the first battery, determine a first target allowable recharge power of the first battery based on the first target SOC, and control the recharge of the first battery using the first target allowable recharge power. And / or before the second battery reaches a second target SOC, the voltage of the second battery increases with the increase of its SOC; during a certain period after the second battery reaches the second target SOC, the voltage of the second battery decreases with the increase of its SOC. The battery management system is used to acquire the second target SOC of the second battery, determine a second target allowable recharge power of the second battery based on the second target SOC, and control the recharge of the second battery using the second target allowable recharge power.

[0029] A sixth aspect provides an electrical device comprising: a first load; a second load; and a battery system according to the fourth or fifth aspect above, the battery system being connected to the first load for providing a first direct current to the first load, and / or the battery system being connected to the second load for providing a second direct current to the second load, wherein the voltage of the first direct current is greater than a voltage threshold, and the voltage of the second direct current is less than the voltage threshold.

[0030] In a seventh aspect, a computer-readable storage medium is provided for storing a computer program that causes a computer to perform the methods described in the first aspect or its implementations.

[0031] Eighthly, a computer program product is provided, comprising: computer program instructions, which, when executed by a computer, cause the computer to perform the method described in the first aspect or its various implementations. Attached Figure Description

[0032] Figure 1 A charging voltage curve of a sodium-ion battery according to an embodiment of this application is shown.

[0033] Figure 2 A schematic flowchart illustrating a battery recharge method according to an embodiment of this application is shown.

[0034] Figure 3 A schematic flowchart illustrating another battery recharge method according to an embodiment of this application is shown.

[0035] Figure 4 A flowchart illustrating a specific battery recharge method according to an embodiment of this application is shown.

[0036] Figure 5 A schematic block diagram of a first battery management system according to an embodiment of this application is shown.

[0037] Figure 6 A schematic block diagram of a second battery management system according to an embodiment of this application is shown.

[0038] Figure 7 A schematic block diagram of a first battery system according to an embodiment of this application is shown.

[0039] Figure 8 A schematic block diagram of a second battery system according to an embodiment of this application is shown.

[0040] Figure 9 A schematic diagram of an electrical device according to an embodiment of this application is shown. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0042] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, rather than to describe a specific order or hierarchy.

[0043] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. It should also be noted in the description of this application that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0044] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0045] In this application, "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0046] In the field of new energy, batteries are the primary power source for electrical devices such as electric vehicles, ships, or spacecraft, and their importance is self-evident. When an electrical device decelerates or coasts, its kinetic energy can drive the electric motor to reverse, turning it into a generator. This allows some of the kinetic energy to be converted into electrical energy, which can then be stored in the battery. This process is known as recharging.

[0047] During battery recharging, overvoltage may occur as the voltage increases. If overvoltage occurs, it can lead to problems such as thermal runaway, short circuits, and permanent capacity degradation. Therefore, it is crucial to minimize the possibility of overvoltage during battery recharging.

[0048] Normally, the battery voltage increases as the charging process progresses. For this type of battery, recharge power control can be performed based on the voltage to reduce the possibility of battery overvoltage.

[0049] However, for some special batteries, a sudden drop in voltage may occur during the charging process. Figure 1 The diagram shows the charging voltage curve of a battery at a certain temperature, where the horizontal axis represents the state of charge (SOC) and the vertical axis represents the open circuit voltage (OCV). It can be seen that the charging voltage curve of this battery exhibits a phenomenon of first decreasing and then suddenly increasing at the end of the charging process (i.e., point A).

[0050] Clearly, the voltage change trend of this type of battery in the AB segment is opposite to that of a regular battery. Therefore, using battery voltage to control recharge power for this type of battery may not effectively reduce the possibility of overvoltage.

[0051] from Figure 1 It can be seen that the difference between the charging voltage curve of this special battery and that of a regular battery begins at point A. Therefore, this application provides a battery recharge method, which determines the target allowable recharge power of the battery based on the target SOC and controls the battery to recharge using the target allowable recharge power. The target SOC is... Figure 1 Point A corresponds to the SOC, meaning that before the target SOC, the battery voltage increases with the increase of the battery SOC. After the battery reaches the target SOC, the battery voltage decreases with the increase of the battery SOC for a certain period of time.

[0052] Before the battery reaches the target SOC, its voltage increases with increasing SOC. However, for a period after reaching the target SOC, the battery voltage decreases with further increases in SOC, resulting in a sudden drop in the charging voltage curve. This indicates that the target SOC represents an inflection point. Therefore, this technical solution determines the target allowable recharge power for the battery based on the target SOC, ensuring that the determined target allowable recharge power is tailored to the battery's characteristics. By controlling the recharge process with this target allowable recharge power, the possibility of battery overvoltage can be effectively reduced.

[0053] The technical solutions described in the embodiments of this application are applicable to various battery-powered devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, electric vehicles, ships, and spacecraft. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.

[0054] It should be understood that the technical solutions described in the embodiments of this application are not limited to the devices described above, but can also be applied to all devices that use batteries. However, for the sake of brevity, the following embodiments are all illustrated using electric vehicles as an example.

[0055] In terms of battery size, the battery in the embodiments of this application can be a single battery cell, a battery module, or a battery pack, etc. Figure 2 A schematic flowchart of a battery recharge method 200 according to an embodiment of this application is shown. Optionally, method 200 may be provided by a battery management system (BMS). Method 200 may include at least some of the following.

[0056] S210: Obtain the target SOC of the battery.

[0057] S220: Determine the target allowable recharge power of the battery based on the target SOC, and control the battery recharge using the target allowable recharge power.

[0058] Specifically, before the battery reaches the target SOC, the battery voltage increases with the increase of battery SOC; after the battery reaches the target SOC, the battery voltage decreases with the increase of battery SOC for a certain period of time.

[0059] Before the battery reaches the target SOC, the battery voltage increases with increasing SOC. However, during a period after reaching the target SOC, the battery voltage decreases with increasing SOC, resulting in a sudden drop in the battery's charging voltage curve. This indicates that the target SOC represents an inflection point. Therefore, this embodiment determines the target allowable recharge power for the battery based on the target SOC, ensuring that the determined target allowable recharge power is adapted to the battery's characteristics. Recharging the battery based on this target allowable recharge power effectively reduces the possibility of overvoltage.

[0060] The target SOC can be understood as the SOC corresponding to the inflection point in the battery's charging voltage curve where the voltage drops. For example... Figure 1 As shown, the SOC corresponding to point A is the target SOC. Optionally, the target SOC can be located at the end of the charging voltage curve. For example, the target SOC can be greater than or equal to 80%.

[0061] Optionally, S210 may specifically include: acquiring the charging voltage curve of the battery, and then acquiring the target SOC based on the charging voltage curve.

[0062] The charging voltage curve is related to the battery material. For example, charging experiments at different temperatures and SOCs can be conducted on the battery to obtain its charging voltage curves. These curves can then be categorized and summarized to obtain the target SOC at different temperatures. When determining the target SOC, the current battery temperature can be determined first, followed by the corresponding charging voltage curve, thus yielding the target SOC.

[0063] Optionally, the BMS can have a pre-set charging voltage curve, allowing the BMS to obtain information based on the charging voltage curve. Alternatively, the charging voltage curve can be stored in the cloud, and the BMS can obtain the charging voltage curve by interacting with the cloud.

[0064] Optionally, the BMS can preset target SOCs corresponding to different temperatures. After the BMS determines the current temperature of the battery, it can determine the target SOC based on that temperature. Alternatively, the target SOCs corresponding to different temperatures can be stored in the cloud, and the BMS obtains the target SOCs by interacting with the cloud.

[0065] In some embodiments, the battery may include a sodium-ion battery. Sodium-ion batteries have good low-temperature performance, maintaining a high capacity retention rate even at low temperatures. Therefore, including a sodium-ion battery allows the electrical device to operate normally in low-temperature environments (e.g., -40°C) without requiring the battery to be heated before operation.

[0066] Of course, the battery can be any type of battery other than a sodium-ion battery, as long as the battery voltage increases with the increase of the battery's SOC before the battery reaches the target SOC, and decreases with the increase of the battery's SOC for a certain period of time after the battery reaches the target SOC.

[0067] In some embodiments, such as Figure 3 As shown, method 200 may further include S230: obtaining the maximum allowable recharge power of the battery and the SOC at the current moment. In this case, S220 may specifically include: determining the target allowable recharge power based on the target SOC, the SOC at the current moment and the maximum allowable recharge power, and controlling the battery recharge with the target allowable recharge power.

[0068] In addition to the target SOC, this technical solution also determines the target allowable recharge power based on the maximum allowable recharge power and the battery's current SOC. That is, it determines the target allowable recharge power based on more parameters. In this way, the accuracy of the target allowable recharge power is higher, which can further reduce the problem of overvoltage in the battery during recharge.

[0069] Optionally, the maximum allowable recharge power can be determined based on the battery's state parameters. State parameters may include, but are not limited to, at least one of the following: temperature, current, voltage, SOC, state of health (SOH), etc.

[0070] The maximum allowable recharge power can be understood as the battery's static recharge capacity, which is the battery's maximum recharge capability. The target allowable recharge power can be understood as the battery's dynamic recharge capacity, which is the actual recharge power of the battery. The target allowable recharge power may vary at different times. The target allowable recharge power is usually less than or equal to the maximum allowable recharge power.

[0071] The embodiments of this application may include two methods for determining the target allowable recharge power.

[0072] Method 1

[0073] In some embodiments, determining the target allowable recharge power based on the target SOC, the current SOC of the battery, and the maximum allowable recharge power may include: if the current SOC is less than or equal to the target SOC, obtaining the battery voltage and determining the target allowable recharge power of the battery based on the battery voltage and the maximum allowable recharge power.

[0074] In addition to the target SOC, the current SOC, and the maximum allowable recharge power, this technical solution also determines the target allowable recharge power based on the battery voltage. That is, it determines the target allowable recharge power based on more parameters, which makes the accuracy of the determined target allowable recharge power higher, thereby further reducing the problem of overvoltage in the battery during recharge.

[0075] The battery voltage can be any single cell voltage among the multiple battery cells. For example, the battery voltage can be the minimum single cell voltage among the multiple battery cells, or it can be the maximum single cell voltage among the multiple battery cells.

[0076] As an example, if the battery voltage is greater than or equal to a first preset voltage, the maximum allowable recharge power is reduced, and the power obtained after reducing the maximum allowable recharge power is the target allowable recharge power. If the battery voltage is less than a second preset voltage, the maximum allowable recharge power is determined as the target allowable recharge power.

[0077] If the battery voltage is greater than or equal to the first preset voltage, it indicates that the battery voltage is too high. At this time, the maximum allowable recharge power is reduced, and the power obtained by reducing the maximum allowable recharge power is determined as the target allowable recharge power. This reduces the actual recharge power of the battery, thereby reducing the possibility of battery overvoltage.

[0078] If the battery voltage is less than the second preset voltage, it indicates that the battery voltage is low at this time, and the possibility of overvoltage is low. Therefore, setting the maximum allowable recharge power as the target allowable recharge power can effectively improve the efficiency of battery recharge.

[0079] It should be noted that prior to S220, the battery recharges based on the maximum recharge power. Therefore, when the battery voltage is greater than or equal to the first preset voltage, the maximum allowable recharge power is limited.

[0080] As an example, the first preset voltage and the second preset voltage can be the battery's full charge cutoff voltage.

[0081] For example, if the battery's maximum allowable recharge power is 100kW and the full charge cutoff voltage is 2.6V, and the battery voltage is 2.8V at the first moment, the maximum allowable recharge power can be reduced, for example, to 80kW. Therefore, the target allowable recharge power at the first moment is 80kW. Afterward, if the battery voltage decreases to 2.5V, which is lower than the full charge cutoff voltage, the target allowable recharge power at the second moment can be restored to the maximum allowable recharge power of 100kW.

[0082] To prevent overvoltage during recharge from limiting the power of electrical devices and affecting user experience, power limiting can be implemented before the battery voltage reaches the full charge cutoff voltage to reduce the possibility of overvoltage.

[0083] Therefore, as another example, the first preset voltage can be the difference between the battery's full charge cutoff voltage and the first voltage, and the second preset voltage can be the difference between the full charge cutoff voltage and the second voltage.

[0084] This technical solution sets the first preset voltage to the difference between the full-charge cutoff voltage and the first voltage. This means that power limiting is implemented before the battery voltage reaches the full-charge cutoff voltage, thus reducing the maximum allowable recharge power and lowering the probability of overvoltage. Furthermore, setting the second preset voltage to the difference between the full-charge cutoff voltage and the second voltage reduces overvoltage caused by further increases in the battery's polarization voltage. It also reduces the formation of substances like sodium dendrites to some extent, effectively improving battery performance.

[0085] Optionally, the first voltage can be determined based on at least one of the following: empirical parameters, the battery's direct current resistance (DCR), and the battery's recharge characteristic curve. Similarly, the second voltage can also be determined based on at least one of the following: empirical parameters, the battery's DCR, and the battery's recharge characteristic curve.

[0086] The first voltage can be the same as the second voltage. For example, the first voltage and the second voltage can both be 300mV, or both can be 400mV.

[0087] Alternatively, the first voltage can be different from the second voltage. For example, the first voltage can be less than the second voltage, such as 300mV for the first voltage and 350mV for the second voltage. Setting the second voltage to be greater than the first voltage, i.e., having an interval between the first and second voltages, such as a 50mV interval, can reduce the likelihood of the battery repeatedly triggering the power limiting strategy, thereby improving recharge efficiency.

[0088] When it is necessary to limit the maximum allowable recharge power, the specific amount to be reduced can be determined based on experience, battery properties, or the application scenario of the battery.

[0089] In some embodiments, if it is necessary to limit the maximum allowable recharge power, the adjustment value of the maximum allowable recharge power can be the same for all cases. In other words, the final target allowable recharge power is the same.

[0090] For example, if the maximum permissible recharge power is 100kW, the target SOC is 95%, and the battery's actual SOC is 98%, reducing the maximum permissible recharge power by 20% will result in a target permissible recharge power of 80kW. Similarly, if the battery's actual SOC is 96%, reducing the maximum permissible recharge power by 20% will also result in a target permissible recharge power of 80kW.

[0091] In other embodiments, the battery voltage can be divided into multiple levels, each with a different adjustment value. In this case, a target adjustment value can be determined based on the battery voltage and multiple correspondences between voltage and power adjustment values. Then, the maximum allowable recharge power is reduced by the target adjustment value to obtain the target allowable recharge power.

[0092] This technical solution establishes multiple correspondences between voltage and power adjustment values, enabling step-by-step power control and more precise power adjustment. This not only ensures recharge efficiency but also effectively reduces the possibility of battery overvoltage.

[0093] For example, when the battery voltage is greater than 3.3V and less than or equal to 3.6V, the power adjustment value is 40%; when the battery voltage is greater than 3.6V and less than or equal to 4V, the power adjustment value is 60%; and when the battery voltage is greater than 4V, the power adjustment value is 80%. Here, an adjustment value of a% indicates a reduction of a% in the maximum allowable recharge power.

[0094] Assuming the first preset voltage is 3.3V, if the maximum allowable recharge power is 100KW, the target SOC is 95%, the actual SOC of the battery is 90%, and the battery voltage is 3.5V, then the power adjustment value is 40%, and the target allowable recharge power is 60KW; if the battery voltage is 4.1V, then the power adjustment value is 80%, and the target allowable recharge power is 20KW.

[0095] Method 2

[0096] In another embodiment, the target allowable recharge power is determined based on the target SOC, the current SOC, and the maximum allowable recharge power. Specifically, this may include: if the current SOC is greater than the target SOC, reducing the maximum allowable recharge power to the target allowable recharge power.

[0097] In other words, the maximum allowable recharge power is limited as long as the current SOC is greater than the target SOC.

[0098] This technical solution, when the actual SOC of the battery is greater than the target SOC, uniformly limits the maximum allowable recharge power, reduces the amount of computation, improves the efficiency of determining the target allowable recharge power, and thus improves the efficiency of battery recharge.

[0099] During the recharge process of the battery at the target allowable recharge power, the battery voltage can be obtained. If the current SOC drops below the target SOC and the battery voltage is less than or equal to the second preset voltage, the target allowable recharge power can be adjusted to the maximum allowable recharge power.

[0100] This technical solution addresses the issue that when the battery voltage drops to less than or equal to a second preset voltage, and the current state of charge (SOC) decreases below the target SOC, it indicates that the battery is less likely to experience overvoltage. In this case, restoring the maximum allowable recharge power allows the battery to recharge at the maximum allowable recharge power, thereby improving the battery's recharge efficiency.

[0101] For example, if the maximum allowable recharge power is 100kW, the second preset voltage is 3.5V, the target SOC is 95%, and the current SOC is 98%, then the current SOC is greater than the target SOC. In this case, the maximum allowable recharge power is limited, for example, to 80kW, and the target allowable recharge power becomes 80kW. If, during the battery's 80kW recharge process, the current SOC drops to 90% and the battery voltage is 3V, then the target allowable recharge power is adjusted back to the maximum allowable recharge power, meaning the target allowable recharge power becomes 100kW.

[0102] Optionally, the battery voltage can be acquired in real time, or the battery voltage can be acquired at preset time intervals, such as 5 milliseconds (ms), 10 ms, 100 ms, etc.

[0103] It should be noted that during the battery recharging process, the battery may be discharging and charging simultaneously. At this time, the charging rate is less than the discharging rate, which will reduce the battery's SOC.

[0104] Below, in conjunction with Figure 4 A specific embodiment of the embodiments of this application is described. Figure 4In this case, both the first and second voltages are 350mV.

[0105] In step 401, the target SOC of the battery is obtained.

[0106] In 402, the current SOC of the battery is obtained in real time.

[0107] In section 403, the maximum allowable recharge power of the battery is determined.

[0108] In 404, determine whether the current SOC is less than or equal to the target SOC.

[0109] If the current SOC is less than or equal to the target SOC, proceed to step 405. If the current SOC is greater than the target SOC, proceed to step 409.

[0110] In step 405, obtain the battery voltage.

[0111] In 406, determine whether the battery voltage is ≥ (full charge cutoff voltage - 350mV).

[0112] If the battery voltage is ≥ (full charge cutoff voltage - 350mV), proceed to step 407; if the battery voltage is < (full charge cutoff voltage - 350mV), proceed to step 408.

[0113] In 407, the maximum allowable recharge power is limited.

[0114] If, after limiting, the battery voltage is less than (full charge cutoff voltage - 350mV), then proceed to step 408.

[0115] In 408, the maximum allowable recharge power is defined as the target allowable recharge power.

[0116] In 409, the maximum allowable recharge power is limited.

[0117] In 410, obtain the current SOC and battery voltage of the battery.

[0118] In step 411, it is determined whether the battery voltage is less than (full charge cutoff voltage - 350mV) and whether the current SOC is less than or equal to the target SOC.

[0119] If the battery voltage is less than (full charge cutoff voltage - 350mV) and the current SOC is less than or equal to the target SOC, proceed to step 412; otherwise, proceed to step 413.

[0120] In 412, the target allowable recharge power is restored to the maximum allowable recharge power.

[0121] In 413, the target allowable recharge power remains unchanged.

[0122] In the embodiments of this application, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0123] Furthermore, without conflict, the various embodiments and / or technical features described in this application can be arbitrarily combined with each other, and the resulting technical solutions should also fall within the protection scope of this application.

[0124] The battery recharge method of the embodiments of this application has been described in detail above. The battery management system of the embodiments of this application will be described below. It should be understood that the battery management system of the embodiments of this application can execute the battery recharge method of the embodiments of this application.

[0125] Figure 5 A schematic block diagram of a first battery management system 500 according to an embodiment of this application is shown. Figure 5 As shown, the first battery management system 500 includes:

[0126] Control unit 510 is configured to acquire a target SOC of the battery, wherein, before the battery reaches the target SOC, the voltage of the battery increases with the increase of the battery SOC, and during a certain period of time after the battery reaches the target SOC, the voltage of the battery decreases with the increase of the battery SOC.

[0127] The control unit 510 is further configured to determine the target allowable recharge power of the battery based on the target SOC, and control the battery recharge at the target allowable recharge power.

[0128] Optionally, in this embodiment of the application, the control unit 510 is specifically used to: obtain the maximum allowable recharge power of the battery and the current state of charge (SOC); and determine the target allowable recharge power based on the target SOC, the current SOC, and the maximum allowable recharge power.

[0129] Optionally, in this embodiment of the application, the control unit 510 is specifically configured to: obtain the battery voltage of the battery when the current SOC is less than or equal to the target SOC; and determine the target allowable recharge power of the battery based on the battery voltage and the maximum allowable recharge power.

[0130] Optionally, in this embodiment of the application, the control unit 510 is specifically configured to: if the battery voltage is greater than or equal to a first preset voltage, reduce the maximum allowable recharge power, and the power obtained after reducing the maximum allowable recharge power is the target allowable recharge power; if the battery voltage is less than or equal to a second preset voltage, determine the maximum allowable recharge power as the target allowable recharge power.

[0131] Optionally, in this embodiment of the application, the first preset voltage is the difference between the full charge cutoff voltage of the battery and a first voltage, and the second preset voltage is the difference between the full charge cutoff voltage and a second voltage.

[0132] Optionally, in this embodiment, the second voltage is greater than the first voltage.

[0133] Optionally, in this embodiment of the application, the control unit 510 is specifically configured to: reduce the maximum allowable recharge power when the current SOC is greater than the target SOC, and the power obtained after reducing the maximum allowable recharge power is the target allowable recharge power.

[0134] Optionally, in this embodiment of the application, the control unit 510 is further configured to: during the process of the battery being recharged at the target allowable recharge power, acquire the battery voltage and the current SOC of the battery during the recharge process; if the current SOC drops below the target SOC and the battery voltage is less than or equal to a second preset voltage, adjust the target allowable recharge power to the maximum allowable recharge power.

[0135] Optionally, in this embodiment of the application, the second preset voltage is the difference between the full charge cutoff voltage of the battery and the second voltage.

[0136] Optionally, in this embodiment of the application, the control unit 510 is specifically configured to: determine a target adjustment value based on the battery voltage of the battery and based on multiple correspondences between voltage and power adjustment values; and reduce the maximum allowable recharge power by the target adjustment value to obtain the target allowable recharge power.

[0137] Optionally, in this embodiment of the application, the battery includes a sodium-ion battery.

[0138] It should be understood that the first battery management system 500 can implement the corresponding operations in the battery recharge method 200, which will not be elaborated here for the sake of brevity.

[0139] Figure 6This is a schematic diagram of the hardware structure of a second battery management system 600 according to an embodiment of this application. The second battery management system 600 includes a memory 610, a processor 620, a communication interface 630, and a bus 640. The memory 610, the processor 620, and the communication interface 630 are interconnected via the bus 640.

[0140] The memory 610 may be a read-only memory (ROM), a static storage device, or a random access memory (RAM). The memory 610 may store a program, and when the program stored in the memory 610 is executed by the processor 620, the processor 620 and the communication interface 630 are used to execute the various steps of the battery recharging method of the embodiments of this application.

[0141] The processor 620 may be a general-purpose central processing unit (CPU), microprocessor, application-specific integrated circuit (ASIC), graphics processing unit (GPU), or one or more integrated circuits, used to execute relevant programs to implement the functions required by the units in the second battery management system 600 of this application embodiment, or to execute the battery recharge method of this application embodiment.

[0142] The processor 620 can also be an integrated circuit chip with signal processing capabilities. In implementation, each step of the battery recharging method according to this application embodiment can be completed by the integrated logic circuitry in the processor 620 or by software instructions.

[0143] The processor 620 described above can also be a general-purpose processor, a digital signal processor (DSP), an ASIC, a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly implemented by the hardware processor, or implemented by a combination of hardware and software modules in the processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory 610. The processor 620 reads the information in memory 610 and, in conjunction with its hardware, completes the functions required by the units included in the second battery management system 600 of the embodiments of this application, or executes the battery recharge method of the embodiments of this application.

[0144] The communication interface 630 uses a transceiver device, such as, but not limited to, a transceiver, to enable communication between the second battery management system 600 and other devices or communication networks.

[0145] Bus 640 may include a pathway for transmitting information between various components of the second battery management system 600 (e.g., memory 610, processor 620, communication interface 630).

[0146] It should be noted that although the above-described second battery management system 600 only shows a memory, processor, and communication interface, those skilled in the art should understand that in specific implementations, the second battery management system 600 may also include other devices necessary for normal operation. Furthermore, depending on specific needs, those skilled in the art should understand that the second battery management system 600 may also include hardware devices for implementing other additional functions. In addition, those skilled in the art should understand that the second battery management system 600 may only include the devices necessary for implementing the embodiments of this application, and may not necessarily include... Figure 6 All the devices shown.

[0147] like Figure 7As shown, this application embodiment also provides a first battery system 700, which may include a battery 710 and a third battery management system 720. Specifically, before the battery 710 reaches a target SOC, the voltage of the battery 710 increases with the increase of the battery 710's SOC; and during a certain period after the battery 710 reaches the target SOC, the voltage of the battery 710 decreases with the increase of the battery 710's SOC.

[0148] Optionally, the third battery management system 720 may be, for example, the first battery management system 500 or the second battery management system 600 described above.

[0149] Alternatively, the battery 710 may include, for example, a sodium-ion battery.

[0150] like Figure 8 As shown in the figure, this application embodiment also provides a second battery system 800, which may include a first battery 810, a second battery 820 and a fourth battery management system 830. The second battery system 800 includes multiple independently configured energy zones, and the first battery 810 and the second battery 820 are respectively configured in different energy zones of the multiple energy zones.

[0151] In this technical solution, the first battery 810 and the second battery 820 are respectively located in different energy zones, which means that the batteries are redundantly designed. In this way, if one battery malfunctions during the use of the electrical device, the other battery can continue to supply power to the electrical device, so that the electrical device can continue to work normally.

[0152] Before reaching the first target SOC, the voltage of the first battery 810 can increase as the SOC of the first battery 810 increases. After reaching the first target SOC, the voltage of the first battery 810 can decrease as the SOC of the first battery 810 increases for a certain period. During this time, the fourth battery management system 830 can acquire the first target SOC of the first battery 810, determine the first target allowable recharge power of the first battery 810 based on the first target SOC, and control the recharge of the first battery 810 using the first target allowable recharge power.

[0153] Alternatively, before reaching the second target SOC, the voltage of the second battery 820 can increase as the SOC of the second battery 820 increases; and during a certain period after the second battery 820 reaches the second target SOC, the voltage of the second battery 820 can decrease as the SOC of the second battery 820 increases. In this case, the fourth battery management system 830 can be used to acquire the second target SOC of the second battery 820, determine the second target allowable recharge power of the second battery 820 based on the second target SOC, and control the recharge of the second battery 820 using the second target allowable recharge power.

[0154] Alternatively, the fourth battery management system 830 may be, for example, the first battery management system 500 or the second battery management system 600 described above.

[0155] The first battery 810 and the second battery 820 can specifically be a battery pack, a battery module, or a battery assembly formed by electrically connecting individual battery cells.

[0156] An energy zone is a portion of the second battery system 800 that can operate and be controlled independently. For example, each energy zone can be charged and discharged independently. Specifically, the energy zones can be divided according to the battery configuration within the second battery system 800. Optionally, when the second battery system 800 includes one or more battery packs, energy zones can be divided within each battery pack. The first battery and the second battery can be located in different energy zones within each battery pack, and separator beams can be provided between the energy zones for isolation. Alternatively, when the second battery system 800 includes multiple battery packs, each battery pack can be considered as a separate energy zone, forming multiple energy zones across the multiple battery packs.

[0157] The first battery 810 and the second battery 820 can be connected in series, or the first battery 810 and the second battery 820 can be connected in parallel.

[0158] This application does not specifically limit the types of the first battery 810 and the second battery 820. The types of the first battery 810 and the second battery 820 may be the same or different. The battery types of the individual cells inside the first battery 810 may be the same or different, and the battery types of the individual cells inside the second battery 820 may be the same or different.

[0159] In some embodiments, the type of the first battery 810 may be different from that of the second battery 820, as long as the output of the first battery 810 and the second battery 820 meets the system requirements.

[0160] For example, the first battery 810 can be a power battery, and the second battery 820 can be an energy battery. Alternatively, the first battery 810 can be an energy battery, and the second battery 820 can be a power battery. This technical solution sets the first battery 810 and the second battery 820 as different types of batteries, enabling the battery system to meet different usage scenarios and thus allowing the battery system to perform under more operating conditions.

[0161] Alternatively, the first and second batteries can be set to be of the same type. For example, both the first and second batteries can be energy-type batteries, or both can be power-type batteries.

[0162] like Figure 9 As shown in the figure, this application embodiment also provides an electrical device 900, which includes a first load 910, a second load 920 and a third battery system 930, wherein the third battery system 930 is connected to the first load 910 and is used to provide a first DC power to the first load 910, and / or the third battery system 930 is connected to the second load 920 and is used to provide a second DC power to the second load 920, wherein the voltage of the first DC power is greater than a voltage threshold and the voltage of the second DC power is less than a voltage threshold.

[0163] In other words, the first load 910 is a high-voltage load, the second load 920 is a low-voltage load, and the third battery system 930 provides low-voltage power to the first load 910 and high-voltage power to the second load 920.

[0164] Optionally, the electrical device 900 may be an electric vehicle, and the third battery system 930 may be the first battery system 700 or the second battery system 800.

[0165] This application also provides a computer-readable storage medium for storing a computer program for performing the methods described in the various embodiments of this application.

[0166] The aforementioned computer-readable storage medium may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0167] This application also provides a computer program product, which includes a computer program stored on a computer-readable storage medium. The computer program includes program instructions that, when executed by a computer, cause the computer to perform the above-described battery recharge method.

[0168] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for recharging a battery, characterized in that, The method includes: The target SOC, the current SOC, and the maximum allowable recharge power of the battery are obtained. Before the battery reaches the target SOC, the voltage of the battery increases with the increase of the battery's SOC. After the battery reaches the target SOC, the voltage of the battery decreases with the increase of the battery's SOC for a certain period of time. Based on the target SOC, the current SOC, and the maximum allowable recharge power, the target allowable recharge power of the battery is determined, and the battery recharge is controlled using the target allowable recharge power. The step of determining the target allowable recharge power based on the target SOC, the current SOC, and the maximum allowable recharge power includes: If the current SOC is greater than the target SOC, the maximum allowable recharge power is reduced, and the power obtained after reducing the maximum allowable recharge power is the target allowable recharge power.

2. The method according to claim 1, characterized in that, The step of determining the target allowable recharge power based on the target SOC, the current SOC, and the maximum allowable recharge power includes: If the current SOC is less than or equal to the target SOC, obtain the battery voltage of the battery; The target allowable recharge power of the battery is determined based on the battery voltage and the maximum allowable recharge power.

3. The method of claim 2, wherein, Determining the target allowable recharge power of the battery based on the battery voltage and the maximum allowable recharge power includes: If the battery voltage is greater than or equal to the first preset voltage, the maximum allowable recharge power is reduced, and the power obtained after reducing the maximum allowable recharge power is the target allowable recharge power; If the battery voltage is less than or equal to the second preset voltage, the maximum allowable recharge power is determined as the target allowable recharge power.

4. The method of claim 3, wherein, The first preset voltage is the difference between the full charge cutoff voltage of the battery and a first voltage, and the second preset voltage is the difference between the full charge cutoff voltage and a second voltage.

5. The method according to claim 4, characterized in that, The second voltage is greater than the first voltage.

6. The method according to claim 1, characterized in that, The method further includes: During the process of the battery being recharged at the target rechargeable power, the battery voltage and the current state of charge (SOC) of the battery are acquired. If the current SOC drops below the target SOC and the battery voltage is less than or equal to the second preset voltage, the target allowable recharge power is adjusted to the maximum allowable recharge power.

7. The method of claim 6, wherein, The second preset voltage is the difference between the full charge cutoff voltage of the battery and the second voltage.

8. The method according to any one of claims 1 to 7, characterized in that, Reducing the maximum allowable recharge power to obtain the target allowable recharge power includes: The target adjustment value is determined based on the battery voltage of the battery and multiple correspondences between voltage and power adjustment values; The target allowable recharge power is obtained by reducing the maximum allowable recharge power by the target adjustment value.

9. The method according to any one of claims 1 to 7, characterized in that, The battery includes a sodium-ion battery.

10. A battery management system, characterized by, include: The control unit is used to acquire the target SOC, the current SOC, and the maximum allowable recharge power of the battery, wherein, before the battery reaches the target SOC, the voltage of the battery increases with the increase of the battery's SOC, and during a certain period of time after the battery reaches the target SOC, the voltage of the battery decreases with the increase of the battery's SOC. The control unit is further configured to, when the current SOC is greater than the target SOC, reduce the maximum allowable recharge power, and the power obtained after reducing the maximum allowable recharge power is the target allowable recharge power, and control the battery recharge with the target allowable recharge power.

11. A battery management system, characterized by, include: Memory, used to store programs; A processor for executing a program stored in the memory, wherein when the program stored in the memory is executed, the processor is configured to perform a battery recharge method according to any one of claims 1 to 9.

12. A battery system characterized by, include: The battery voltage increases with increasing SOC before the battery reaches the target SOC, and decreases with increasing SOC for a certain period of time after the battery reaches the target SOC. A battery management system for performing a battery recharge method according to any one of claims 1 to 9.

13. A battery system characterized by, The battery system includes a first battery, a second battery, and a battery management system. The battery system includes multiple independently configured energy zones, and the first battery and the second battery are respectively configured in different energy zones of the multiple energy zones. Specifically, before the first battery reaches the first target SOC, the voltage of the first battery increases with the increase of the first battery's SOC. During a certain period after the first battery reaches the first target SOC, the voltage of the first battery decreases with the increase of the first battery's SOC. The battery management system is used to acquire the first target SOC of the first battery, the first SOC at the current moment, and the first maximum allowable recharge power. If the first SOC at the current moment is greater than the first target SOC, the first maximum allowable recharge power is reduced. The power obtained after reducing the first maximum allowable recharge power is the first target allowable recharge power, and the recharge of the first battery is controlled using the first target allowable recharge power; and / or Before the second battery reaches the second target SOC, the voltage of the second battery increases with the increase of the SOC of the second battery. During a certain period after the second battery reaches the second target SOC, the voltage of the second battery decreases with the increase of the SOC of the second battery. The battery management system is used to obtain the second target SOC of the second battery, the current second SOC and the second maximum allowable recharge power. If the current second SOC is greater than the second target SOC, the second maximum allowable recharge power is reduced. The power obtained after reducing the second maximum allowable recharge power is the second target allowable recharge power, and the recharge of the second battery is controlled by the second target allowable recharge power.

14. An electrical device, comprising: include: First load; Second load; According to claim 12 or 13, the battery system is connected to the first load for providing a first direct current to the first load, and / or the battery system is connected to the second load for providing a second direct current to the second load, wherein the voltage of the first direct current is greater than a voltage threshold and the voltage of the second direct current is less than the voltage threshold.

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