Battery equalization method, battery management system, battery system and electric device

Abstract

The embodiment of the invention provides a battery equalization method, a battery management system, a battery system and an electric device. The method comprises the following steps: acquiring voltages of a plurality of single batteries in the battery device; and under the condition that the voltages of the plurality of single batteries are in a plurality of preset intervals, the battery device is controlled to be balanced according to the preset intervals in which the voltages of the plurality of single batteries are located, the plurality of preset intervals comprise at least two of a first preset interval in which the voltage is smaller than the first voltage, a second preset interval in which the voltage is between the first voltage and the second voltage, and a third preset interval in which the voltage is larger than the second voltage. According to the battery equalization method, the battery management system, the battery system and the electric device provided by the embodiment of the invention, the battery device can be reasonably equalized, the performance of the battery device is improved, and the service life of the battery device is prolonged.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to battery balancing methods, battery management systems, battery systems, and power-consuming devices. Background Technology

[0002] Due to their advantages such as high energy density, rechargeability, safety, and environmental friendliness, battery devices are widely used in new energy vehicles, consumer electronics, energy storage systems, and other fields.

[0003] To improve the performance and lifespan of battery devices, battery balancing is necessary. Currently, balancing is typically performed based on the voltage differences between multiple battery cells. However, when the state of charge (SOC) of multiple battery cells is near a plateau region—for example, when the voltages of multiple battery cells are all within the voltage range corresponding to the plateau region—the voltage variation in the plateau region is very small. In this case, balancing based on the voltage differences of the battery cells becomes impossible.

[0004] Therefore, how to reasonably balance battery devices, especially for battery devices with long plateau regions or multiple plateau regions, is one of the urgent problems to be solved. Summary of the Invention

[0005] This application provides a battery balancing method, a battery management system, a battery system, and an electrical device, which can reasonably balance the battery device and improve its performance and lifespan.

[0006] In a first aspect, a battery balancing method is provided, comprising: acquiring the voltage of multiple battery cells in a battery device; when the voltage of the multiple battery cells is in multiple preset intervals, controlling the battery device to perform balancing according to the multiple preset intervals in which the voltage of the multiple battery cells is located, wherein the multiple preset intervals include at least two of a first preset interval where the voltage is less than a first voltage, a second preset interval where the voltage is between the first voltage and a second voltage, and a third preset interval where the voltage is greater than the second voltage, wherein the first voltage is the voltage corresponding to the lower limit of the plateau region of the battery cell, the second voltage is the voltage corresponding to the upper limit of the plateau region, and the balancing includes at least one level of multi-level balancing, wherein the balancing capacity of the multi-level balancing is different.

[0007] In this embodiment, when multiple battery cells of the battery device are near the platform area, the battery device can be balanced to different degrees according to the preset range in which the multiple battery cells are located. This can reasonably achieve the balance of the battery device and improve the performance and service life of the battery device.

[0008] In one possible implementation, when the voltages of multiple battery cells fall within multiple preset ranges, the battery device is controlled to perform equalization based on the preset ranges in which the multiple battery cells fall. This includes: when there are battery cells among the multiple battery cells whose voltages are within a preset range adjacent to that of a reference battery cell, the battery device is controlled to perform a first equalization; and / or, when there are battery cells among the multiple battery cells whose voltages are within a preset range separated from that of the reference battery cell, the battery device is controlled to perform a second equalization, wherein the reference battery cell is the battery cell with the highest or lowest voltage among the multiple battery cells, and the equalization charge of the first equalization is less than the equalization charge of the second equalization.

[0009] In this embodiment, the battery device can be balanced to different degrees based on the relationship between the voltage of other battery cells and the voltage of the reference battery cell in different preset intervals, such as when they are adjacent or separated. This can reasonably balance the battery cells when the voltage of multiple battery cells is near the plateau region. At the same time, the balancing method used is relatively simple and can reduce the data overhead during balancing.

[0010] In one possible implementation, when there are battery cells among the multiple battery cells whose voltage is in a preset range adjacent to that of a reference battery cell, controlling the battery device to perform a first equalization includes: when the voltage of the reference battery cell among the multiple battery cells is in a first preset range and there is a first battery cell among the multiple battery cells in a second preset range, controlling the first battery cell to perform a first equalization, wherein the reference battery cell is the battery cell with the lowest voltage.

[0011] In this embodiment, when the voltage of the reference battery cell with the lowest voltage among multiple battery cells is within a first preset range, and there is a first battery cell among the multiple battery cells within a second preset range, the first battery cell can be controlled to perform a first equalization. Thus, even when the voltages of multiple battery cells are in different preset ranges near the plateau region and the differences are small, the battery device can be controlled to perform an equalization with a relatively small amount, thereby reasonably achieving battery device equalization.

[0012] In one possible implementation, when there is a battery cell among the multiple battery cells whose voltage is in a preset range adjacent to that of a reference battery cell, controlling the battery device to perform a first equalization includes: when the voltage of the reference battery cell among the multiple battery cells is in a second preset range and there is a second battery cell among the multiple battery cells whose voltage is in a third preset range, controlling the second battery cell to perform a first equalization, wherein the reference battery cell is the battery cell with the lowest voltage.

[0013] In this embodiment, when the voltage of the reference battery cell with the lowest voltage among multiple battery cells is within a second preset range, and there is a second battery cell among the multiple battery cells with a voltage within a third preset range, the second battery cell can be controlled to perform a first equalization. Thus, even when the voltages of multiple battery cells are in different preset ranges near the plateau region and the differences are small, the battery device can be controlled to perform an equalization with a relatively small amount, thereby reasonably achieving battery device equalization.

[0014] In one possible implementation, when there is a battery cell among the multiple battery cells whose voltage is separated from the voltage of the reference battery cell by a preset range, controlling the battery device to perform a second equalization includes: when the voltage of the reference battery cell among the multiple battery cells is in a first preset range and there is a third battery cell among the multiple battery cells whose voltage is in a third preset range, controlling the third battery cell to perform a second equalization, wherein the reference battery cell is the battery cell with the lowest voltage.

[0015] In this embodiment, when the voltage of the reference battery cell with the lowest voltage among multiple battery cells is within a first preset range, and there is a third battery cell among the multiple battery cells with a voltage within a third preset range, the third battery cell can be controlled to perform a second equalization. Thus, even when the voltages of multiple battery cells are in different preset ranges near the plateau region and differ significantly, the battery device can be controlled to perform a relatively large equalization, thereby reasonably achieving battery device equalization.

[0016] In one possible implementation, the first equilibrium includes either active equilibrium or passive equilibrium, and the second equilibrium includes either active equilibrium or passive equilibrium.

[0017] In the embodiments of this application, the battery device can be balanced by active balancing or passive balancing, thus allowing for flexible setting or selection of the balancing method for the battery device.

[0018] In one possible implementation, when there is a battery cell among the multiple battery cells whose voltage is in a preset range adjacent to that of a reference battery cell, controlling the battery device to perform a first equalization includes: when the voltage of the reference battery cell among the multiple battery cells is in a second preset range and there is a fourth battery cell among the multiple battery cells whose voltage is in a first preset range, controlling the reference battery cell to perform a first equalization, wherein the reference battery cell is the battery cell with the largest voltage.

[0019] In this embodiment, when the voltage of the reference battery cell with the highest voltage among multiple battery cells is within a second preset range, and there is a fourth battery cell among the multiple battery cells with a voltage within a first preset range, the reference battery cell can be controlled to perform a first equalization. Thus, even when the voltages of multiple battery cells are in different preset ranges near the plateau region and the differences are small, the battery device can be controlled to perform an equalization with a relatively small amount, thereby reasonably achieving battery device equalization.

[0020] In one possible implementation, controlling a reference battery cell to perform a first equalization includes controlling a first equalization between the reference battery cell and a fourth battery cell, the first equalization including active equalization.

[0021] In one possible implementation, when there is a battery cell among the plurality of battery cells whose voltage is in a preset range adjacent to that of a reference battery cell, the battery device is controlled to perform a first equalization, which includes: when the voltage of the reference battery cell among the plurality of battery cells is in a third preset range and there is a fifth battery cell among the plurality of battery cells whose voltage is in a second preset range, the reference battery cell is controlled to perform a first equalization, wherein the reference battery cell is the battery cell with the largest voltage.

[0022] In this embodiment, when the voltage of a reference battery cell among multiple battery cells is in a third preset range and there is a fifth battery cell among the multiple battery cells whose voltage is in a second preset range, the reference battery cell can be controlled to perform a first equalization. Thus, even when the voltages of multiple battery cells are in different preset ranges near the plateau region and the differences are small, the battery device can be controlled to perform an equalization with a relatively small amount, thereby reasonably achieving battery device equalization.

[0023] In one possible implementation, controlling the reference battery cell to perform a first equalization includes: controlling the reference battery cell and the fifth battery cell to perform a first equalization, the first equalization including active equalization.

[0024] In one possible implementation, when there is a battery cell among the multiple battery cells whose voltage is separated from the voltage of the reference battery cell by a preset range, the battery device is controlled to perform a second equalization, which includes: when the voltage of the reference battery cell among the multiple battery cells is in a third preset range and there is a sixth battery cell among the multiple battery cells whose voltage is in a first preset range, the reference battery cell is controlled to perform a second equalization, wherein the reference battery cell is the battery cell with the largest voltage.

[0025] In this embodiment, when the voltage of a reference battery cell among multiple battery cells is in a third preset range and there is a sixth battery cell among the multiple battery cells whose voltage is in a first preset range, the reference battery cell can be controlled to perform a second equalization. Therefore, even when the voltages of multiple battery cells are in different preset ranges near the plateau region and differ significantly, the battery device can be controlled to perform a relatively large equalization, thus reasonably achieving battery device equalization.

[0026] In one possible implementation, controlling the reference battery cell to perform a second equalization includes controlling a second equalization between the reference battery cell and the sixth battery cell, the second equalization including active equalization.

[0027] In one possible implementation, the battery cell includes at least one platform region.

[0028] In this embodiment, when a single battery cell has at least one plateau region, the battery device can be balanced according to the voltage of multiple single battery cells in multiple preset intervals corresponding to each plateau region. In this way, the battery device can be reasonably balanced when it is charged or discharged to the vicinity of each plateau region.

[0029] In one possible implementation, the battery cell includes a sodium-ion battery cell.

[0030] In the embodiments of this application, since the plateau region of sodium-ion battery cells is relatively long and the self-discharge rate of battery cells varies greatly, the balancing scheme provided in this application can reasonably achieve the balancing of sodium-ion battery devices to meet the balancing requirements of sodium-ion battery devices, improve the performance and lifespan of battery devices.

[0031] Secondly, a battery management system is provided, comprising: an acquisition unit for acquiring the voltages of multiple battery cells in a battery device; and a control unit for controlling the battery device to perform balancing based on the multiple preset intervals in which the voltages of the multiple battery cells are located, when the voltages of the multiple battery cells are in multiple preset intervals, wherein the multiple preset intervals include at least two of a first preset interval where the voltage is less than a first voltage, a second preset interval where the voltage is between the first voltage and a second voltage, and a third preset interval where the voltage is greater than the second voltage, wherein the first voltage is the voltage corresponding to the lower limit of the plateau region of the battery cell, the second voltage is the voltage corresponding to the upper limit of the plateau region, and the balancing includes at least one level of multi-level balancing, wherein the balancing capacity of the multi-level balancing is different.

[0032] In one possible implementation, the control unit is specifically configured to control the battery device to perform a first equalization when there are battery cells among the multiple battery cells whose voltage is within a preset range adjacent to the voltage of the reference battery cell; and / or, to control the battery device to perform a second equalization when there are battery cells among the multiple battery cells whose voltage is within a preset range separated from the voltage of the reference battery cell, wherein the reference battery cell is the battery cell with the highest or lowest voltage among the multiple battery cells, and the equalization charge of the first equalization is less than the equalization charge of the second equalization.

[0033] In one possible implementation, the control unit is specifically used to control the first battery cell to perform a first equalization when the voltage of the reference battery cell among a plurality of battery cells is in a first preset range and there is a first battery cell among the plurality of battery cells in a second preset range, wherein the reference battery cell is the battery cell with the lowest voltage.

[0034] In one possible implementation, the control unit is specifically used to control the second battery cell to perform a first equalization when the voltage of the reference battery cell among the multiple battery cells is in a second preset range and there is a second battery cell among the multiple battery cells with a voltage in a third preset range, wherein the reference battery cell is the battery cell with the lowest voltage.

[0035] In one possible implementation, the control unit is specifically used to control the third battery cell to perform a second equalization when the voltage of the reference battery cell among the multiple battery cells is in a first preset range and there is a third battery cell among the multiple battery cells with a voltage in a third preset range, wherein the reference battery cell is the battery cell with the lowest voltage.

[0036] In one possible implementation, the first equilibrium includes either active equilibrium or passive equilibrium, and the second equilibrium includes either active equilibrium or passive equilibrium.

[0037] In one possible implementation, the control unit is specifically used to control the reference battery cell to perform a first equalization when the voltage of the reference battery cell among the multiple battery cells is within a second preset range and there is a fourth battery cell among the multiple battery cells whose voltage is within a first preset range. The reference battery cell is the battery cell with the largest voltage.

[0038] In one possible implementation, the control unit is specifically used to control a first equalization between the reference battery cell and the fourth battery cell, the first equalization including active equalization.

[0039] In one possible implementation, the control unit is specifically used to control a reference battery cell to perform a first equalization when the voltage of the fifth battery cell among a plurality of battery cells is in a third preset range and there is a fifth battery cell among the plurality of battery cells with a voltage in a second preset range. The reference battery cell is the battery cell with the largest voltage.

[0040] In one possible implementation, the control unit is specifically used to control a first equalization between the reference battery cell and the fifth battery cell, the first equalization including active equalization.

[0041] In one possible implementation, the control unit is specifically used to control the reference battery cell to perform a second equalization when the voltage of the reference battery cell among the multiple battery cells is in a third preset range and there is a sixth battery cell among the multiple battery cells whose voltage is in a first preset range. The reference battery cell is the battery cell with the largest voltage.

[0042] In one possible implementation, the control unit is specifically used to control a second equalization between the reference battery cell and the sixth battery cell, the second equalization including active equalization.

[0043] In one possible implementation, the battery cell includes at least one platform region.

[0044] In one possible implementation, the battery cell includes a sodium-ion battery cell.

[0045] Thirdly, a battery management system is provided, the battery management system including a memory and a processor, the memory for storing instructions, and the processor for reading instructions and executing methods as described in the first aspect and any possible implementation thereof.

[0046] Fourthly, a battery system is provided, comprising: a battery device including a plurality of battery cells, each battery cell including at least one platform region; and a battery management system as in any possible implementation of the second or third aspect.

[0047] Fifthly, a battery system is provided, comprising: a first energy region, wherein a first battery device is disposed in the first energy region, the first battery device including a plurality of first battery cells; a second energy region, wherein a second battery device is disposed in the second energy region, the second battery device including a plurality of second battery cells, the first energy region and the second energy region being independently disposed; and a battery management system as in any possible implementation of the second or third aspect, wherein the first battery cell includes at least one platform region, and / or, the second battery cell includes at least one platform region.

[0048] A sixth aspect provides an electrical device comprising: a load; and a battery system as in any possible implementation of the fourth or fifth aspect, the battery system being connected to the load for supplying power to the load.

[0049] A seventh aspect provides an electrical device comprising: a first load; a second load; and a battery system as in any possible implementation of the fourth or fifth aspect, the battery system being connected to the first load for providing a first direct current to the first load, and the battery system being connected to the second load for providing a second direct current to the second load, the voltage of the first direct current being greater than the voltage of the second direct current.

[0050] Eighthly, a chip is provided, comprising: a processor for calling and running a computer program from memory, causing a device on which the chip is mounted to perform the methods as described in the first aspect and any possible implementation thereof.

[0051] Ninth aspect, a computer program is provided that, when executed by a computer, causes the computer to implement the methods of the first aspect and any possible implementation thereof.

[0052] In a tenth aspect, a computer-readable storage medium is provided for storing a computer program that, when executed by a computer, causes the computer to implement the methods described in the first aspect and any possible implementation thereof.

[0053] Eleventhly, a computer program product is provided, including computer program instructions that, when executed by a computer, cause the computer to implement the methods as described in the first aspect and any possible implementation thereof. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of a vehicle provided in an embodiment of this application.

[0055] Figure 2 This is a schematic flowchart of the battery balancing method provided in an embodiment of this application.

[0056] Figure 3 This is a schematic diagram of the OCV curve of a lithium iron phosphate battery cell provided in the embodiments of this application.

[0057] Figure 4 This is another schematic flowchart of the battery balancing method provided in the embodiments of this application.

[0058] Figure 5 This is another schematic flowchart of the battery balancing method provided in the embodiments of this application.

[0059] Figure 6 This is another schematic flowchart of the battery balancing method provided in the embodiments of this application.

[0060] Figure 7 This is a schematic block diagram of the battery management system provided in the embodiments of this application.

[0061] Figure 8 This is another schematic block diagram of the battery management system provided in the embodiments of this application.

[0062] Figure 9 This is a schematic block diagram of the battery system provided in the embodiments of this application.

[0063] Figure 10 This is another schematic block diagram of the battery system provided in the embodiments of this application.

[0064] Figure 11 This is a schematic block diagram of the electrical device provided in the embodiments of this application.

[0065] Figure 12 This is another schematic block diagram of the electrical device provided in the embodiments of this application. Detailed Implementation

[0066] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0067] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "a plurality of" means two or more, unless otherwise explicitly defined. The terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing description of the drawings of this application, are intended to cover non-exclusive inclusion.

[0068] The term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " in this text generally indicates that the preceding and following related objects have an "or" relationship.

[0069] In this document, the term "embodiment" means that a particular 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 separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0070] In this application, the terms "upper," "lower," "left," "right," "inner," and "outer," indicating orientation or positional relationships, are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. "Vertical" is not vertical in the strict sense, but within the allowable tolerance range. "Parallel" is not parallel in the strict sense, but within the allowable tolerance range.

[0071] 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.

[0072] Due to their advantages such as high energy density, rechargeability, safety, and environmental friendliness, battery devices are widely used in new energy vehicles, consumer electronics, energy storage systems, and other fields.

[0073] Due to differences in manufacturing processes, usage conditions, and natural aging, the characteristics of each individual cell in a battery device, such as capacity, internal resistance, and self-discharge rate, cannot be completely identical, affecting the device's performance and lifespan. Furthermore, this inconsistency is amplified during charging and discharging, further impacting the battery device's performance and lifespan. For example, during charging, cells with smaller capacity and higher internal resistance may be fully charged first, while those with larger capacity and lower internal resistance may be charged later. To prevent overcharging, charging may stop when the cells with smaller capacity and higher internal resistance reach the charging cutoff condition, while the cells with larger capacity and lower internal resistance are not yet fully charged. This results in a decrease in the usable capacity of the battery device.

[0074] Therefore, battery equalization can be performed to improve the performance and lifespan of the battery device. Currently, equalization is usually based on the voltage differences between multiple battery cells. However, when the state of charge (SOC) of multiple battery cells is near a plateau region, for example, when the voltage of multiple battery cells is all within the voltage range corresponding to the plateau region, the voltage change in the plateau region is very small. In this case, equalization based on the voltage differences of the battery cells is not possible.

[0075] For example, some battery cells, such as lithium iron phosphate battery cells, have a long plateau region, which means that the corresponding SOC range is relatively large. If the battery device is balanced by relying solely on the voltage difference when all battery cells are in the non-plateau region, it may not meet the balancing requirements of the battery device.

[0076] For example, in addition to its relatively long plateau region, sodium-ion battery cells also exhibit relatively large differences in self-discharge rates, leading to greater balancing requirements for the battery system. Relying solely on voltage differences when all cells are in the non-plateau region to balance the battery system is insufficient to meet these balancing needs.

[0077] In view of this, embodiments of this application provide a battery balancing method, a battery management system, a battery system, and a power-consuming device. The battery balancing method includes: acquiring the voltage of multiple battery cells in a battery device; when the voltage of the multiple battery cells is in multiple preset intervals, controlling the battery device to perform balancing according to the multiple preset intervals in which the voltage of the multiple battery cells is located, the multiple preset intervals include at least two of a first preset interval where the voltage is less than a first voltage, a second preset interval where the voltage is between the first voltage and a second voltage, and a third preset interval where the voltage is greater than the second voltage, wherein the first voltage is the voltage corresponding to the lower limit of the plateau region of the battery cell, the second voltage is the voltage corresponding to the upper limit of the plateau region, and the balancing includes at least one level of multi-level balancing, wherein the balancing capacity of the multi-level balancing is different.

[0078] The battery balancing method, battery management system, battery system, and power-consuming device provided in this application embodiment can reasonably balance the battery device, thereby improving the performance and service life of the battery device.

[0079] The technical solutions described in the embodiments of this application are applicable to various devices that use battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, electric vehicles, ships, and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.

[0080] 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 vehicles as an example.

[0081] Figure 1 This is a schematic diagram of a vehicle provided in an embodiment of this application.

[0082] Vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. The interior of vehicle 1 can house a motor 40, a controller 30, and a battery system 6000. The controller 30 can manage the power supply from the battery system 6000 to the motor 40. For example, the battery system 6000 can be located at the bottom, front, or rear of vehicle 1.

[0083] The battery system 6000 can be used to power the vehicle 1. In some embodiments, the battery system 6000 can serve as the operating power source for the vehicle 1's electrical system, for example, to meet the power requirements of the vehicle 1 during startup, navigation, and operation.

[0084] In some embodiments, the battery system 6000 can also serve as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0085] To meet diverse power demands, the battery system 6000 can include multiple battery cells, which can be connected in series, parallel, or a combination of both. For example, multiple battery cells can first be connected in series, parallel, or a combination of both to form a battery module. These battery modules can then be connected in series, parallel, or a combination of both to form a battery device. In other words, multiple battery cells can directly form a battery device; or they can first be formed into battery modules, and then the battery modules can be combined into a battery device.

[0086] The battery system 6000 may also include a battery management system, which can be used to monitor the state parameters of the battery device, such as current, voltage, SOC and temperature, in order to control the charging and discharging of the battery device.

[0087] It should be understood that Figure 1 The components shown are just examples. In actual applications, the components may have different names, or they may be added or deleted as needed.

[0088] The following combination Figures 2 to 6 The battery balancing method provided in the embodiments of this application will be described by way of example.

[0089] Figure 2This is a schematic flowchart of the battery balancing method provided in an embodiment of this application.

[0090] 210, Obtain the voltage of multiple individual battery cells in the battery device.

[0091] As an example, multiple battery cells can be connected in series.

[0092] 220. When the voltage of multiple battery cells is in multiple preset ranges, the battery device is controlled to balance according to the multiple preset ranges in which the voltage of multiple battery cells is located.

[0093] The multiple preset intervals include at least two of the following: a first preset interval where the voltage is less than the first voltage, a second preset interval where the voltage is between the first voltage and the second voltage, and a third preset interval where the voltage is greater than the second voltage. The first voltage is the voltage corresponding to the lower limit of the plateau region of the battery cell, and the second voltage is the voltage corresponding to the upper limit of the plateau region. The balancing includes at least one level of multi-level balancing, and the balancing capacity of the multi-level balancing is different.

[0094] The plateau region refers to a segment in the open circuit voltage (OCV) curve of a battery cell during charging, discharging, or resting processes where the voltage remains stable or changes slowly with the state of charge (SOC).

[0095] The resting process can include the resting process after charging or the resting process after discharging.

[0096] For example, Figure 3 The figure shows the OCV curve of a single lithium iron phosphate battery cell. A1 is the lower limit of the plateau region, and the voltage corresponding to A1 is the first voltage. A2 is the upper limit of the plateau region, and the voltage corresponding to A2 is the second voltage. The voltage range below A1 is the first preset range, the voltage range between A1 and A2 is the second preset range, and the voltage range above A2 is the third preset range.

[0097] Similarly, B1 is another lower limit of the plateau region, and the voltage corresponding to B1 is another first voltage. B2 is another upper limit of the plateau region, and the voltage corresponding to B2 is another second voltage. The voltage range below B1 is another first preset range, the range between B1 and B2 is another second preset range, and the range above B2 is another third preset range.

[0098] As an example, the second voltage can be greater than or equal to the first voltage.

[0099] If the second voltage is greater than the first voltage, then the second preset interval is the interval where the voltage is greater than or equal to the first voltage and less than or equal to the second voltage.

[0100] If the second voltage is equal to the second voltage, then the second preset interval is the interval where the voltage is equal to the first voltage or the second voltage.

[0101] The voltage of multiple individual battery cells falling within multiple preset ranges can include the following situations: A portion of the battery cells are located in the first preset range, while the other portion are located in the second preset range. Some battery cells are in the second preset range, and other battery cells are in the third preset range; Some battery cells are located in the first preset range, and other battery cells are located in the third preset range; or... Some battery cells are in the first preset range, some are in the second preset range, and some are in the third preset range.

[0102] As an example, multi-level equilibrium can include not only first equilibrium, second equilibrium, and third equilibrium.

[0103] As an example, the balanced power can include capacity or State of Charge (SOC). For instance, the balanced SOC of the first balance is less than the balanced SOC of the second balance, and the balanced SOC of the second balance is less than the balanced SOC of the third balance.

[0104] As an example, if some battery cells are in a first preset range and another portion are in a second preset range, the other portion of battery cells can be controlled to discharge ΔSOC1 of charge to the balancing resistor. If some battery cells are in the second preset range and another portion are in a third preset range, the other portion of battery cells can be controlled to discharge ΔSOC2 of charge to the balancing resistor. If some battery cells are in the first preset range and another portion are in the third preset range, the other portion of battery cells can be controlled to discharge ΔSOC3 of charge to the balancing resistor. Wherein, ΔSOC1 < ΔSOC2 < ΔSOC3.

[0105] In this embodiment, the magnitude relationship of ΔSOC1, ΔSOC2, and ΔSOC3 can be determined based on the position of the plateau region on the OCV curve. For example, if the difference between the SOC corresponding to the lower limit of the plateau region and the lower limit of the SOC allowed by the battery cell is less than the difference between the SOC corresponding to the upper limit of the plateau region and the upper limit of the SOC allowed by the battery cell, then ΔSOC1 (first equilibrium) < ΔSOC2 (second equilibrium) < ΔSOC3 (third equilibrium); if the difference between the SOC corresponding to the lower limit of the plateau region and the lower limit of the SOC allowed by the battery cell is greater than the difference between the SOC corresponding to the upper limit of the plateau region and the upper limit of the SOC allowed by the battery cell, then ΔSOC2 (first equilibrium) < ΔSOC1 (second equilibrium) < ΔSOC3 (third equilibrium).

[0106] In this embodiment, when multiple battery cells of the battery device are near the platform area, the battery device can be balanced to different degrees according to the preset range in which the multiple battery cells are located. This can reasonably achieve the balance of the battery device and improve the performance and service life of the battery device.

[0107] Continue to combine as follows Figure 4 The battery balancing method provided in the embodiments of this application will be further illustrated by example.

[0108] 410, Obtain the voltage of multiple individual battery cells in the battery device.

[0109] As an example, multiple battery cells can be connected in series.

[0110] 420a, when there are battery cells among multiple battery cells whose voltage is in a preset range adjacent to the voltage of the reference battery cell, the battery device is controlled to perform a first equalization.

[0111] The reference cell is the cell with the highest or lowest voltage among multiple cells.

[0112] The equilibrium charge in the first equilibrium is less than the equilibrium charge in the second equilibrium.

[0113] That is, in this embodiment, the voltage of the reference battery cell among the multiple battery cells is in any one of the first preset interval, the second preset interval, and the third preset interval, and there is a battery cell among the multiple cells whose voltage is in a preset interval adjacent to the arbitrary preset interval. The battery device is first equalized by controlling the battery cell whose voltage is in a preset interval adjacent to the arbitrary preset interval to release ΔSOC1 of charge to the equalization resistor.

[0114] 420b, when there is a battery cell among multiple battery cells whose voltage is separated from the voltage of the reference battery cell by a preset range, the battery device is controlled to perform a second equalization.

[0115] That is, in this embodiment, the voltage of the reference battery cell among the multiple battery cells is in one of the first preset range or the third preset range, and there is a battery cell among the multiple battery cells whose voltage is in another preset range of the first preset range or the electrical preset range. The battery device is controlled to perform a second equalization, such as controlling the battery cell whose voltage is in the other preset range of the first preset range or the electrical preset range to release ΔSOC2 of electricity.

[0116] As an example, in steps 420a and 420b, ΔSOC1 < ΔSOC2.

[0117] As an example, during a complete charge or discharge cycle, such as when the battery device is charged from a discharge cutoff condition (or when the voltage and / or SOC is greater than the discharge cutoff condition) to a charge cutoff condition, or when the battery device is discharged from a charge cutoff condition to a discharge cutoff condition (or when the voltage and / or SOC is greater than the discharge cutoff condition), step 420a may be performed only; or step 420b may be performed only; or step 420a may be performed first, followed by step 420b; or step 420b may be performed first, followed by step 420a; or steps 420a and 420b may be performed simultaneously. The specific execution method depends on the actual voltage conditions of the multiple battery cells.

[0118] In this embodiment, the battery device can be balanced to different degrees based on the relationship between the voltage of other battery cells and the voltage of the reference battery cell in different preset intervals, such as when they are adjacent or separated. This can reasonably balance the battery cells when the voltage of multiple battery cells is near the plateau region. At the same time, the balancing method used is relatively simple and can reduce the data overhead during balancing.

[0119] In the embodiments of this application, the reference battery cell can change during charging or discharging. For example, in the initial stage of charging, the reference battery cell can be battery cell A among multiple battery cells; as charging progresses, the reference battery cell can be battery cell B among multiple battery cells.

[0120] Of course, the reference battery cell can remain unchanged during charging or discharging. For example, throughout the entire charging process, the reference battery cell is always battery cell A among multiple battery cells.

[0121] Figure 5 This is a schematic flowchart of the battery balancing method provided in an embodiment of this application.

[0122] 510, Obtain the voltage of multiple individual battery cells in the battery device.

[0123] As an example, multiple battery cells can be connected in series.

[0124] 520a, when the voltage of a reference battery cell among multiple battery cells is in a first preset range and there is a first battery cell among multiple battery cells in a second preset range, the first battery cell is controlled to perform a first equalization.

[0125] The reference cell is the cell with the lowest voltage.

[0126] As an example, among multiple battery cells, the battery cell with the lowest voltage has a voltage lower than the first voltage, and among the multiple battery cells, there is a first battery cell with a voltage greater than or equal to the first voltage and less than or equal to the second voltage. In this case, the first battery cell can be controlled to perform a first equalization, such as controlling the first battery cell to release ΔSOC1 of charge to the equalization resistor.

[0127] As another example, among multiple battery cells, the voltage of the battery cell with the lowest voltage is less than the first voltage, and there is a battery cell with a voltage equal to the first voltage (the first voltage equals the second voltage). In this case, the first battery cell can be controlled to perform a first equalization, such as controlling the first battery cell to release ΔSOC1 of charge to the equalization resistor.

[0128] In this embodiment, when the voltage of the reference battery cell with the lowest voltage among multiple battery cells is within a first preset range, and there is a first battery cell among the multiple battery cells within a second preset range, the first battery cell can be controlled to perform a first equalization. Thus, even when the voltages of multiple battery cells are in different preset ranges near the plateau region and the differences are small, the battery device can be controlled to perform an equalization with a relatively small amount, thereby reasonably achieving battery device equalization.

[0129] 520b, when the voltage of the reference battery cell among multiple battery cells is in a second preset range and there is a second battery cell among multiple battery cells with a voltage in a third preset range, the second battery cell is controlled to perform a first equalization.

[0130] As an example, among multiple battery cells, the voltage of the battery cell with the lowest voltage is equal to the first voltage (the first voltage is equal to the second voltage), and there is a second battery cell with a voltage greater than the second voltage. In this case, the second battery cell can be controlled to perform a first equalization, such as controlling the second battery cell to release ΔSOC1 of charge to the equalization resistor.

[0131] As another example, among multiple battery cells, the voltage of the battery cell with the lowest voltage is equal to the first voltage (the first voltage is equal to the second voltage), and there is a second battery cell with a voltage greater than the second voltage. In this case, the second battery cell can be controlled to perform a first equalization, such as controlling the second battery cell to release ΔSOC1 of charge to the equalization resistor.

[0132] In this embodiment, when the voltage of the reference battery cell with the lowest voltage among multiple battery cells is within a second preset range, and there is a second battery cell among the multiple battery cells with a voltage within a third preset range, the second battery cell can be controlled to perform a first equalization. Thus, even when the voltages of multiple battery cells are in different preset ranges near the plateau region and the differences are small, the battery device can be controlled to perform an equalization with a relatively small amount, thereby reasonably achieving battery device equalization.

[0133] 520c, when the voltage of the reference battery cell among multiple battery cells is in a first preset range and there is a third battery cell among multiple battery cells whose voltage is in a third preset range, the third battery cell is controlled to perform a second equalization.

[0134] As an example, among multiple battery cells, the battery cell with the lowest voltage has a voltage lower than the first voltage, and there is a third battery cell with a voltage higher than the second voltage. In this case, the third battery cell can be controlled to perform a second equalization, such as controlling the third battery cell to release ΔSOC2 of charge to the equalization resistor.

[0135] As another example, among multiple battery cells, the battery cell with the lowest voltage has a voltage lower than the first voltage, and there is a third battery cell with a voltage higher than the second voltage. In this case, the third battery cell can be controlled to perform a second equalization, such as controlling the third battery cell to release ΔSOC2 of charge to the equalization resistor.

[0136] As an example, in step 520, ΔSOC1 < ΔSOC2.

[0137] In this embodiment, when the voltage of the reference battery cell with the lowest voltage among multiple battery cells is within a first preset range, and there is a third battery cell among the multiple battery cells with a voltage within a third preset range, the third battery cell can be controlled to perform a second equalization. Thus, even when the voltages of multiple battery cells are in different preset ranges near the plateau region and differ significantly, the battery device can be controlled to perform a relatively large equalization, thereby reasonably achieving battery device equalization.

[0138] As an example, during a complete charge or discharge cycle, such as when the battery device is charging from a discharge cutoff condition (or when the voltage and / or SOC is greater than the discharge cutoff condition) to a charge cutoff condition, or when the battery device is discharging from a charge cutoff condition to a discharge cutoff condition (or when the voltage and / or SOC is greater than the discharge cutoff condition), step 520a may be executed only; or step 520b may be executed only; or step 520c may be executed only; or step 520a may be executed first, followed by step 520b; or steps 520a and 520c may be executed first, followed by step 520b, and so on. The specific execution method can be determined based on the actual voltage conditions of multiple battery cells.

[0139] In the embodiments of this application, the reference battery cell with the lowest voltage can change during charging or discharging. For example, in the initial stage of charging, the reference battery cell with the lowest voltage can be battery cell A among multiple battery cells; as charging progresses, the reference battery cell with the lowest voltage can be battery cell B among multiple battery cells.

[0140] Of course, the reference cell with the lowest voltage can remain constant during charging or discharging. For example, throughout the entire charging process, the reference cell with the lowest voltage is always cell A among the multiple cells.

[0141] In some embodiments, the balancing in step 520 may include active balancing or passive balancing.

[0142] As an example, the above-mentioned control of the first battery cell to perform the first equalization, control of the second battery cell to perform the first equalization, and control of the third battery cell to perform the second equalization can all be active equalization.

[0143] Active balancing is a process of transferring energy from higher-capacity battery cells to lower-capacity battery cells.

[0144] For example, the first battery cell is controlled to transfer ΔSOC1 of its charge to the reference battery cell with the lowest voltage. For example, the second battery cell is controlled to transfer ΔSOC1 of its charge to the reference battery cell with the lowest voltage. For example, the third battery cell is controlled to transfer ΔSOC2 of its charge to the reference battery cell with the lowest voltage.

[0145] As an example, the above-mentioned control of the first battery cell to perform the first equalization, control of the second battery cell to perform the first equalization, and control of the third battery cell to perform the second equalization can all be passive equalization.

[0146] Passive balancing works by discharging the energy of higher-charge battery cells as heat, such as by discharging into their connected balancing modules or balancing resistors, thus reducing the charge level of the higher-charge battery cells to the same level as the lower-charge battery cells.

[0147] For example, the first battery cell can be controlled to release ΔSOC1 of its charge to an equalization module, such as an equalization resistor.

[0148] For example, the second battery cell can be controlled to release ΔSOC1 of charge to the equalization module, such as the equalization resistor.

[0149] For example, the third battery cell can be controlled to release ΔSOC2 of its charge to the equalization module, such as the equalization resistor.

[0150] In the embodiments of this application, the battery device can be balanced by active balancing or passive balancing, thus allowing for flexible setting or selection of the balancing method for the battery device.

[0151] Figure 6 This is a schematic flowchart of the battery balancing method provided in an embodiment of this application.

[0152] 610, Obtain the voltage of multiple individual battery cells in the battery device.

[0153] As an example, multiple battery cells can be connected in series.

[0154] 620a, when the voltage of a reference battery cell among multiple battery cells is within a second preset range and there is a fourth battery cell among multiple battery cells whose voltage is within a first preset range, the reference battery cell is controlled to perform a first equalization.

[0155] The reference cell is the cell with the highest voltage.

[0156] As an example, if the voltage of the reference battery cell with the highest voltage among multiple battery cells is greater than or equal to the first voltage and less than or equal to the second voltage, and there is a fourth battery cell among the multiple battery cells with a voltage lower than the first voltage, the reference battery cell can be controlled to perform the first equalization.

[0157] As another example, the voltage of the reference battery cell with the highest voltage among multiple battery cells is equal to the first voltage (the first voltage and the second voltage are equal), and there is a fourth battery cell among the multiple battery cells with a voltage lower than the first voltage, so the reference battery cell can be controlled to perform the first equalization.

[0158] As an example, the first equilibrium includes passive equilibrium.

[0159] For example, the amount of charge ΔSOC1 that the reference battery cell can release to the equalization module can be controlled.

[0160] As another example, the first equilibrium may include an active equilibrium.

[0161] For example, a first equalization can be controlled between a reference battery cell and a battery cell with lower charge, such as the fourth battery cell. That is, the reference battery cell can be controlled to transfer ΔSOC1 of charge to the battery cell with lower charge, such as the fourth battery cell.

[0162] In this embodiment, when the voltage of the reference battery cell with the highest voltage among multiple battery cells is within a second preset range, and there is a fourth battery cell among the multiple battery cells with a voltage within a first preset range, the reference battery cell can be controlled to perform a first equalization. Thus, even when the voltages of multiple battery cells are in different preset ranges near the plateau region and the differences are small, the battery device can be controlled to perform an equalization with a relatively small amount, thereby reasonably achieving battery device equalization.

[0163] 620b, when the voltage of a reference battery cell among multiple battery cells is in a third preset range and there is a fifth battery cell among multiple battery cells whose voltage is in a second preset range, the reference battery cell is controlled to perform a first equalization.

[0164] As an example, if the voltage of the reference battery cell with the highest voltage among multiple battery cells is greater than the second voltage, and there is a fifth battery cell among multiple battery cells with a voltage greater than or equal to the first voltage and less than or equal to the second voltage, the reference battery cell can be controlled to perform a first equalization.

[0165] As another example, the voltage of the reference battery cell with the highest voltage among multiple battery cells is greater than the second voltage, and there is a fifth battery cell among multiple battery cells with a voltage equal to the first voltage (the first voltage and the second voltage are equal), which can control the reference battery cell to perform the first equalization.

[0166] As an example, the first equilibrium includes passive equilibrium.

[0167] For example, the amount of charge ΔSOC1 that the reference battery cell can release to the equalization module can be controlled.

[0168] As another example, the first equilibrium may include an active equilibrium.

[0169] For example, a first equalization can be controlled between a reference battery cell and a battery cell with lower charge, such as the fifth battery cell. That is, the reference battery cell can be controlled to transfer ΔSOC1 of charge to the battery cell with lower charge, such as the fifth battery cell.

[0170] In this embodiment, when the voltage of a reference battery cell among multiple battery cells is in a third preset range and there is a fifth battery cell among the multiple battery cells whose voltage is in a second preset range, the reference battery cell can be controlled to perform a first equalization. Thus, even when the voltages of multiple battery cells are in different preset ranges near the plateau region and the differences are small, the battery device can be controlled to perform an equalization with a relatively small amount, thereby reasonably achieving battery device equalization.

[0171] 630c, when the voltage of the reference battery cell among multiple battery cells is in the third preset range and there is a sixth battery cell among multiple battery cells whose voltage is in the first preset range, the reference battery cell is controlled to perform a second equalization.

[0172] As an example, if the voltage of the reference battery cell with the highest voltage among multiple battery cells is greater than the second voltage, and there is a sixth battery cell among multiple battery cells with a voltage less than or equal to the first voltage, the reference battery cell can be controlled to perform a second equalization.

[0173] As an example, the second equilibrium includes passive equilibrium.

[0174] For example, it is possible to control the amount of electricity ΔSOC2 released by the reference battery cell to the equalization module.

[0175] As another example, the second equilibrium may include an active equilibrium.

[0176] For example, a second equalization can be controlled between a reference battery cell and a lower-charge battery cell, such as the sixth battery cell. That is, the reference battery cell can be controlled to transfer ΔSOC2 of charge to a lower-charge battery cell, such as the fifth battery cell.

[0177] As an example, during a complete charge or discharge cycle, such as when the battery device is charged from the discharge cutoff condition (or the voltage and / or SOC is greater than the discharge cutoff condition) to the charge cutoff condition, or when the battery device is discharged from the charge cutoff condition to the discharge cutoff condition (or the voltage and / or SOC is greater than the discharge cutoff condition), step 620a may be executed only; or step 620b may be executed only; or step 620c may be executed only; or step 620a may be executed first, followed by step 620b; or steps 620b and 620c may be executed first, followed by step 620b, etc. The specific execution method can be determined based on the actual voltage conditions of multiple battery cells.

[0178] For example, when executing steps 620b and 620c simultaneously, if active balancing is being performed, the amount of charge ΔSOC1 can be transferred from the reference battery cell with the highest voltage to the fifth battery cell, and the amount of charge ΔSOC2 can be transferred to the sixth battery cell.

[0179] In the embodiments of this application, the reference battery cell with the highest voltage can change during charging or discharging. For example, in the initial stage of charging, the reference battery cell with the highest voltage can be battery cell A among multiple battery cells; as charging progresses, the reference battery cell with the highest voltage can be battery cell B among multiple battery cells.

[0180] Of course, the reference battery cell with the highest voltage can remain unchanged during charging or discharging. For example, throughout the entire charging process, the reference battery cell with the highest voltage is always battery cell A among the multiple battery cells.

[0181] In this embodiment, when the voltage of a reference battery cell among multiple battery cells is in a third preset range and there is a sixth battery cell among the multiple battery cells whose voltage is in a first preset range, the reference battery cell can be controlled to perform a second equalization. Therefore, even when the voltages of multiple battery cells are in different preset ranges near the plateau region and differ significantly, the battery device can be controlled to perform a relatively large equalization, thus reasonably achieving battery device equalization.

[0182] In some embodiments, a battery cell includes at least one platform region.

[0183] As an example, as shown above, a single battery cell can have two plateau regions.

[0184] When the voltage of multiple battery cells falls within multiple preset intervals corresponding to a plateau region, the battery device can be balanced, such as through a first equalization and / or a second equalization, based on the conditions of the multiple preset intervals corresponding to the plateau region in which the multiple battery cells are located.

[0185] When the voltage of multiple battery cells falls within multiple preset intervals corresponding to another platform region, the battery device can be controlled to perform equalization, such as first equalization and / or second equalization, based on the conditions of the multiple preset intervals corresponding to the other platform region in which the multiple battery cells are located.

[0186] Of course, the first equilibrium corresponding to the two cases mentioned above can be the same or different; similarly, the second equilibrium corresponding to the two cases mentioned above can be the same or different.

[0187] When the voltages of multiple battery cells are in multiple preset ranges that can simultaneously satisfy the two platform regions, such as the voltage of the reference battery cell with the lowest voltage being less than the first voltage corresponding to the first platform region, and the voltage of one of the multiple battery cells being greater than the second voltage corresponding to the second platform region, the battery device can be balanced according to the equalization capacity corresponding to the first platform region, or the battery device can be balanced according to the equalization capacity corresponding to the second platform region.

[0188] In this embodiment, when a battery cell has at least one plateau region, the battery device can be balanced according to the voltage of multiple battery cells in multiple preset intervals corresponding to each plateau region. In this way, the battery device can be reasonably balanced when it is charged or discharged to the vicinity of each plateau region.

[0189] In some embodiments, the battery device includes a sodium-ion battery cell.

[0190] Because sodium-ion battery cells exhibit good low-temperature performance, their capacity retention remains high even in low-temperature environments. Therefore, sodium-ion battery devices can operate normally in low-temperature environments (such as -40°C), eliminating the need for the battery to heat up before operation, thus improving the user experience.

[0191] In the embodiments of this application, since the plateau region of sodium-ion battery cells is relatively long and the self-discharge rate of battery cells varies greatly, the balancing scheme provided in this application can reasonably achieve the balancing of sodium-ion battery devices to meet the balancing requirements of sodium-ion battery devices, improve the performance and lifespan of battery devices.

[0192] In some embodiments, the equilibrium SOC of the first equilibrium is 1% to 8%, and the equilibrium SOC of the second equilibrium is 0% to 1%.

[0193] As an example, the equilibrium SOC of the first equilibrium is 1%, and the equilibrium SOC of the second equilibrium is 0.3%.

[0194] As an example, when a battery cell includes multiple plateau regions (e.g., two plateau regions), the equalization capacity corresponding to the multi-level balancing when the voltage of multiple battery cells is in multiple preset intervals corresponding to the first plateau region is different from that when the voltage of multiple battery cells is in multiple preset intervals corresponding to the second plateau region. For example, the equalization capacity corresponding to the first and second preset intervals corresponding to the first plateau region is different from that corresponding to the first and second preset intervals corresponding to the second plateau region.

[0195] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes 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.

[0196] The battery management system of the embodiments of this application has been described in detail above. The following will be combined with… Figure 7 and Figure 8 The battery management system of the embodiments of this application is described in detail. The technical features described in the method embodiments are applicable to the following embodiments of the battery management system.

[0197] Figure 7 This is a schematic block diagram of the battery management system provided in an embodiment of this application. Figure 7 The battery management system 4000 includes some or all of the following components.

[0198] The battery management system 4000 includes an acquisition unit 4010 and a control unit 4020.

[0199] The acquisition unit 4010 is used to acquire the voltage of multiple battery cells in the battery device; the control unit 4020 is used to control the battery device to perform balancing based on the multiple preset intervals in which the voltage of the multiple battery cells is located when the voltage of the multiple battery cells is in multiple preset intervals. The multiple preset intervals include at least two of the following: a first preset interval where the voltage is less than a first voltage, a second preset interval where the voltage is between the first voltage and a second voltage, and a third preset interval where the voltage is greater than the second voltage. The first voltage is the voltage corresponding to the lower limit of the plateau region of the battery cell, and the second voltage is the voltage corresponding to the upper limit of the plateau region. The balancing includes at least one level of multi-level balancing, and the balancing capacity of the multi-level balancing is different.

[0200] In some embodiments, the control unit 4020 is specifically configured to control the battery device to perform a first equalization when there are battery cells among the plurality of battery cells whose voltage is within a preset range adjacent to the voltage of a reference battery cell; and / or, to control the battery device to perform a second equalization when there are battery cells among the plurality of battery cells whose voltage is within a preset range separated from the voltage of a reference battery cell, wherein the reference battery cell is the battery cell with the highest or lowest voltage among the plurality of battery cells, and the equalization charge of the first equalization is less than the equalization charge of the second equalization.

[0201] In some embodiments, the control unit 4020 is specifically used to control the first battery cell to perform a first equalization when the voltage of the reference battery cell among a plurality of battery cells is in a first preset range and there is a first battery cell among the plurality of battery cells in a second preset range, wherein the reference battery cell is the battery cell with the lowest voltage.

[0202] In some embodiments, the control unit 4020 is specifically used to control the second battery cell to perform a first equalization when the voltage of the reference battery cell among a plurality of battery cells is in a second preset range and there is a second battery cell among the plurality of battery cells with a voltage in a third preset range, wherein the reference battery cell is the battery cell with the lowest voltage.

[0203] In some embodiments, the control unit 4020 is specifically used to control the third battery cell to perform a second equalization when the voltage of the reference battery cell among a plurality of battery cells is in a first preset range and there is a third battery cell among the plurality of battery cells with a voltage in a third preset range, wherein the reference battery cell is the battery cell with the lowest voltage.

[0204] In some embodiments, the first equilibrium includes active equilibrium or passive equilibrium, and the second equilibrium includes active equilibrium or passive equilibrium.

[0205] In some embodiments, the control unit 4020 is specifically used to control the reference battery cell to perform a first equalization when the voltage of the reference battery cell among a plurality of battery cells is within a second preset range and there is a fourth battery cell among the plurality of battery cells whose voltage is within a first preset range. The reference battery cell is the battery cell with the largest voltage.

[0206] In some embodiments, the control unit 4020 is specifically used to control a first equalization between a reference battery cell and a fourth battery cell, the first equalization including active equalization.

[0207] In some embodiments, the control unit 4020 is specifically configured to control the reference battery cell to perform a first equalization when the voltage of the reference battery cell among a plurality of battery cells is in a third preset range and there is a fifth battery cell among the plurality of battery cells with a voltage in a second preset range. The reference battery cell is the battery cell with the largest voltage.

[0208] In some embodiments, the control unit 4020 is specifically used to control a first equalization between a reference battery cell and a fifth battery cell, the first equalization including active equalization.

[0209] In some embodiments, the control unit 4020 is specifically configured to control the reference battery cell to perform a second equalization when the voltage of the reference battery cell among the plurality of battery cells is in a third preset range and there is a sixth battery cell among the plurality of battery cells whose voltage is in a first preset range. The reference battery cell is the battery cell with the largest voltage.

[0210] In some embodiments, the control unit 4020 is specifically used to control a second equalization between a reference battery cell and a sixth battery cell, the second equalization including active equalization.

[0211] In some embodiments, a battery cell includes at least one platform region.

[0212] In some embodiments, the battery cell includes a sodium-ion battery cell.

[0213] It should be understood that the above and other operations and / or functions of the various modules in the battery management system 4000 are for the purpose of achieving Figures 2 to 6 For the sake of brevity, the corresponding processes in each method will not be elaborated here.

[0214] Figure 8 A schematic block diagram of a battery management system 4000 according to an embodiment of this application is shown. Figure 8 As shown, the battery management system 4000 includes a processor 5010 and a memory 5020, wherein the memory 5020 is used to store instructions, and the processor 5010 is used to read instructions and execute the methods of the various embodiments of the present application based on the instructions.

[0215] The memory 5020 can be a separate device independent of the processor 5010, or it can be integrated into the processor 5010.

[0216] Optionally, such as Figure 8 As shown, the battery management system 4000 may also include a transceiver 5030, and the processor 5010 can control the transceiver 5030 to communicate with other devices. Specifically, it can send information or data to other devices, or receive information or data sent by other devices.

[0217] It should be understood that the processor in the embodiments of this application may be an integrated circuit chip with signal processing capabilities. In implementation, the steps of the above method embodiments can be completed by integrated logic circuits in the processor's hardware or by instructions in software form. The processor described above can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding 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. The storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method.

[0218] It is understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0219] like Figure 9 As shown in the figure, this application embodiment also provides a battery system 6000, which may include a battery device 6100 and a battery management system 4000.

[0220] The battery device 6100 includes a plurality of battery cells, each battery cell including at least one platform region.

[0221] For details regarding the battery device 6100 and the battery management system 4000, please refer to the descriptions above. For the sake of brevity, these details will not be repeated here.

[0222] like Figure 10 As shown in the figure, this application embodiment also provides a battery system 6000, which includes a first energy region 6010, a second energy region 6020 and a battery management system 4000.

[0223] The first energy region 6010 is provided with a first battery device 6011, which includes a plurality of first battery cells.

[0224] The second energy region 6020 is provided with a second battery device 6021, which includes a plurality of second battery cells. The first energy region 6010 and the second energy region 6020 are independently provided.

[0225] The first battery cell includes at least one platform region, and / or the second battery cell includes multiple platform regions.

[0226] In this embodiment, the first battery device 6011 and the second battery device 6021 are respectively located in different energy zones, i.e., redundant design is implemented. In this way, for example, if one battery device malfunctions during the use of the electrical device, the other battery device can continue to supply power to the electrical device, and the electrical device can continue to work normally.

[0227] In this embodiment, the battery system may include multiple independent energy zones, each of which is equipped with a battery pack. For example, the battery system may include two independent energy zones, such as a first energy zone and a second energy zone, with a first battery device 6011 and a second battery device 6021 respectively in the two energy zones.

[0228] Energy zones are the parts of a battery system that can operate and be controlled independently. For example, each energy zone can be charged and discharged separately. Specifically, energy zones can be divided according to the configuration of the battery devices in the battery system.

[0229] As an example, each energy zone's battery unit can individually supply power to the load of the electrical device.

[0230] For example, the first battery device 6011 and the second battery device 6021 can supply power to the load of the electrical device independently.

[0231] The first battery device 6011 and the second battery device 6021 can simultaneously supply power to the load of the electrical device. Alternatively, one of the first battery device 6011 and the second battery device 6021 can be used preferentially to supply power to the load of the electrical device, and if the power of one battery device is exhausted or malfunctions, the other battery device can be switched to supply power to the load of the electrical device.

[0232] As another example, one of the first battery device 6011 and the second battery device 6021 can be used to supply power to the load of the electrical device. In this case, the other of the first battery device 6011 and the second battery device 6021 can be used to transfer energy to that first battery device to supply power to it.

[0233] As an example, the first battery device 6011 and the second battery device 6021 can be charged by a charging device.

[0234] As an example, a charging device may include a charging station and / or a charging gun.

[0235] As an example, the first battery device 6011 and the second battery device 6021 can be charged separately or as a whole.

[0236] For example, the charging device can charge the first battery device 6011 and the second battery device 6021 as a whole, such as after the first battery device 6011 and the second battery device 6021 are connected in parallel or in series, and then charged by the charging device.

[0237] For example, the charging device can charge the first battery device 6011 and the second battery device 6021 separately. Alternatively, the charging device may include a first charging device and a second charging device, with the first charging device charging the first battery device 6011 and the second charging device charging the second battery device 6021. The first and second charging devices can also be designed as an integrated unit or as independent units.

[0238] As an example, energy can be transferred between the first battery device 6011 and the second battery device 6021.

[0239] For example, the first battery device 6011 and the second battery device 6021 can be connected via a bidirectional power module. The bidirectional power module is a device or circuit capable of bidirectional energy transfer, such as a direct current / direct current (DC / DC) converter circuit, a flyback transformer, etc.

[0240] For example, the battery system may include a battery management system that can control the charging and discharging of the first battery device 6011 and the second battery device 6021, as well as the energy transfer between the first battery device 6011 and the second battery device 6021.

[0241] For example, the battery system may include two battery management systems, which are used to control the charging and discharging of the first battery device 6011 and the second battery device 6021, respectively. The two battery management systems can communicate with each other, and one battery management system can be used to control the energy transfer between the first battery device 6011 and the second battery device 6021.

[0242] The first battery device 6011 can be a battery pack, a battery module, or a battery assembly formed by electrically connecting individual battery cells. The second battery device 6021 can be a battery pack, a battery module, or a battery assembly formed by electrically connecting individual battery cells.

[0243] Optionally, when the battery system includes one or more battery packs, energy zones can be divided within each battery pack. The first battery device 6011 and the second battery device 6021 can be disposed in different energy zones within each battery pack, and partition beams can be provided between the energy zones to isolate them. Alternatively, when the battery system includes multiple battery packs, each battery pack can be considered as an energy zone, and multiple energy zones can be formed among the multiple battery packs.

[0244] In the embodiments of this application, the first battery device 6011 and the second battery device 6021 may be of the same type or different types. For example, the first battery device 6011 may be a power battery and the second battery device 6021 may be an energy battery; or, the first battery device 6011 may be an energy battery and the second battery device 6021 may be a power battery; or both the first battery device 6011 and the second battery device 6021 may be either power batteries or energy batteries.

[0245] like Figure 11 and Figure 12 As shown in the figure, this application embodiment also provides an electrical device 7000.

[0246] like Figure 11 As shown, the electrical device 7000 includes a load 7100 and a battery system 6000, wherein the battery system 6000 is connected to the load 7100 and is used to supply power to the load 7100.

[0247] As an example, the battery system 6000 is used to provide DC power to the load 7100, the voltage of which is greater than a voltage threshold. That is, the load 7100 is a high-voltage load, and the battery system 6000 can provide high-voltage power to the load 7100.

[0248] As an example, electrical appliances may also include other loads such as low-voltage loads.

[0249] like Figure 12 As shown, the electrical device 7000 includes a first load 7010, a second load 7020, and a battery system 6000. The battery system 6000 is connected to the first load 7010 and the second load 7020, and is used to provide a first DC power to the first load 7010 and a second DC power to the second load 7020, respectively. The voltage of the first DC power is greater than the voltage of the second DC power.

[0250] In other words, the first load is a high-voltage load, and the second load is a low-voltage load. The battery system provides low-voltage power to the first load and high-voltage power to the second load.

[0251] For details on the 6000 battery system, please refer to the above text. Figure 9 and Figure 10For the sake of brevity, the relevant descriptions in the original document will not be repeated here.

[0252] In this application, "high voltage" and "low voltage" are relative concepts; that is, high voltage involves a voltage higher than low voltage. Generally speaking, the difference between high-voltage and low-voltage related circuits or components is that high-voltage related circuits or components refer to circuits or components that can be directly or indirectly connected to the battery system. This is because the battery system consists of several battery cells, providing a relatively high voltage.

[0253] As will be understood by those skilled in the art, high voltage generally refers to voltages greater than tens of volts, hundreds of volts, or higher. Circuits and components operating at voltages greater than tens of volts, hundreds of volts, or higher can be used or processed. For example, circuits and components operating at voltages greater than 30V AC RMS and less than or equal to 1000V AC RMS, or greater than 60V DC and less than or equal to 1500V DC. Here, V represents volts, AC RMS represents the effective power in the alternating current waveform, and DC represents direct current.

[0254] Low voltage generally refers to voltages of tens of volts, 10 volts, or lower. Low-voltage related circuits or components refer to circuits and components that can use or handle voltages of tens of volts, 10 volts, or lower. For example, circuits and components with a maximum operating voltage of no more than 30V AC RMS or no more than 60V DC. Here, V represents volts, AC RMS represents the effective power in the alternating current waveform, and DC represents direct current.

[0255] This application also provides a computer-readable storage medium for storing computer programs.

[0256] When the computer program is run on a computer, it causes the computer to perform the various methods of the embodiments of this application.

[0257] This application also provides a computer program product, including computer program instructions.

[0258] When the computer program instructions are run on a computer, the computer causes the computer to perform the various methods of the embodiments of this application.

[0259] This application also provides a computer program.

[0260] When the computer program is run on a computer, it causes the computer to perform the various methods of the embodiments of this application.

[0261] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0262] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0263] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection involved in the embodiments of this application may be through some interfaces, and the indirect coupling or communication connection of devices or units may be electrical, mechanical, or other forms.

[0264] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0265] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0266] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0267] 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 of balancing a battery, characterized by, The method comprises: acquiring voltages of a plurality of battery cells in a battery device; in a case where the voltages of the plurality of battery cells are in a plurality of preset intervals, controlling the battery device to perform balancing according to the plurality of preset intervals in which the plurality of battery cells are located, the plurality of preset intervals comprising at least two of a first preset interval in which the voltage is less than a first voltage, a second preset interval in which the voltage is between the first voltage and a second voltage, and a third preset interval in which the voltage is greater than the second voltage, the first voltage being a voltage corresponding to a lower limit of a platform region of the battery cell, and the second voltage being a voltage corresponding to an upper limit of the platform region, the balancing comprising at least one level of a plurality of levels of balancing, the balancing electric quantity of the plurality of levels of balancing being different.

2. The method of claim 1, wherein, The method of controlling the battery device to perform balancing according to the plurality of preset intervals in which the plurality of battery cells are located in a case where the voltages of the plurality of battery cells are in a plurality of preset intervals comprises: in a case where there is a battery cell in the plurality of battery cells whose voltage is in an adjacent preset interval to a voltage of a reference battery cell, controlling the battery device to perform first balancing; and / or, in a case where there is a battery cell in the plurality of battery cells whose voltage is in a spaced preset interval to the voltage of the reference battery cell, controlling the battery device to perform second balancing, wherein the reference battery cell is a battery cell with the maximum or minimum voltage in the plurality of battery cells, and the balancing electric quantity of the first balancing is less than the balancing electric quantity of the second balancing.

3. The method of claim 2, wherein, The method of controlling the battery device to perform first balancing in a case where there is a battery cell in the plurality of battery cells whose voltage is in an adjacent preset interval to a voltage of a reference battery cell comprises: in a case where the voltage of the reference battery cell is in the first preset interval and there is a first battery cell in the plurality of battery cells in the second preset interval, controlling the first battery cell to perform the first balancing, the reference battery cell being a battery cell with the minimum voltage.

4. The method of claim 2, wherein, The method of controlling the battery device to perform first balancing in a case where there is a battery cell in the plurality of battery cells whose voltage is in an adjacent preset interval to a voltage of a reference battery cell comprises: in a case where the voltage of the reference battery cell is in the second preset interval and there is a second battery cell in the plurality of battery cells in the third preset interval, controlling the second battery cell to perform the first balancing, the reference battery cell being a battery cell with the minimum voltage.

5. The method of claim 2, wherein, The method of controlling the battery device to perform second balancing in a case where there is a battery cell in the plurality of battery cells whose voltage is in a spaced preset interval to the voltage of the reference battery cell comprises: in a case where the voltage of the reference battery cell is in the first preset interval and there is a third battery cell in the plurality of battery cells in the third preset interval, controlling the third battery cell to perform the second balancing, the reference battery cell being a battery cell with the minimum voltage.

6. The method of claim 3, wherein, The first equilibrium includes active equilibrium or passive equilibrium, and the second equilibrium includes active equilibrium or passive equilibrium.

7. The method of claim 2, wherein, In the case where there is a battery cell among the plurality of battery cells whose voltage is within a preset range adjacent to the voltage of a reference battery cell, controlling the battery device to perform a first equalization includes: When the voltage of a reference battery cell among the plurality of battery cells is within the second preset range and there is a fourth battery cell among the plurality of battery cells whose voltage is within the first preset range, the reference battery cell is controlled to perform the first equalization, wherein the reference battery cell is the battery cell with the highest voltage.

8. The method of claim 7, wherein, The control of the reference battery cell to perform the first equalization includes: The first equalization is controlled between the reference battery cell and the fourth battery cell, and the first equalization includes active equalization.

9. The method of claim 2, wherein, In the case where there is a battery cell among the plurality of battery cells whose voltage is within a preset range adjacent to the voltage of a reference battery cell, controlling the battery device to perform a first equalization includes: When the voltage of a reference battery cell among the plurality of battery cells is within the third preset range and there is a fifth battery cell among the plurality of battery cells whose voltage is within the second preset range, the reference battery cell is controlled to perform the first equalization, wherein the reference battery cell is the battery cell with the largest voltage.

10. The method of claim 9, wherein, The control of the reference battery cell to perform the first equalization includes: The reference battery cell and the fifth battery cell are controlled to perform a first equalization, which includes active equalization.

11. The method of claim 2, wherein, In the case where there is a battery cell among the plurality of battery cells whose voltage is separated from the voltage of the reference battery cell by a preset range, controlling the battery device to perform a second equalization includes: When the voltage of a reference battery cell among the plurality of battery cells is within the third preset range and there is a sixth battery cell among the plurality of battery cells whose voltage is within the first preset range, the reference battery cell is controlled to perform the second equalization, wherein the reference battery cell is the battery cell with the highest voltage.

12. The method of claim 11, wherein, The control of the reference battery cell to perform the second equalization includes: The second equalization is controlled between the reference battery cell and the sixth battery cell, and the second equalization includes active equalization.

13. The method of claim 1, wherein, The battery cell includes at least one of the platform regions.

14. The method according to any one of claims 1 to 13, characterized in that, The battery cell includes a sodium-ion battery cell.

15. A battery management system, characterized by, include: The acquisition unit is used to acquire the voltage of multiple individual battery cells in the battery device; A control unit is configured to control the battery device to perform equalization according to a plurality of preset intervals of voltages of the plurality of battery cells when the voltages of the plurality of battery cells are in the plurality of preset intervals, the plurality of preset intervals including at least two of a first preset interval in which the voltage is less than a first voltage, a second preset interval in which the voltage is between the first voltage and a second voltage, and a third preset interval in which the voltage is greater than the second voltage, the first voltage being a voltage corresponding to a lower limit of a platform region of the battery cell, the second voltage being a voltage corresponding to an upper limit of the platform region, the equalization including at least one of a plurality of levels of equalization, the equalization of the plurality of levels of equalization being different.

16. A battery management system, characterized by, Comprising: a memory for storing a program; a processor for executing the program stored in the memory, the processor being configured to execute the method according to any one of claims 1 to 14 when the program stored in the memory is executed.

17. A battery system characterized by, Comprising: a battery device including a plurality of battery cells, the battery cells including at least one platform region; and the battery management system according to claim 15 or 16.

18. A battery system characterized by, Comprising: a first energy region provided with a first battery device, the first battery device including a plurality of first battery cells; a second energy region provided with a second battery device, the second battery device including a plurality of second battery cells, the first energy region and the second energy region being independently provided; and the battery management system according to claim 15 or 16, wherein the first battery cells include at least one platform region, and / or the second battery cells include at least one platform region.

19. An electrical device, comprising: Comprising: a load; and the battery system according to claim 17 or 18, the battery system being connected to the load for supplying power to the load.

20. An electrical device, comprising: Comprising: a first load; a second load; and the battery system according to claim 17 or 18, the battery system being connected to the first load for providing first direct current to the first load, and the battery system being connected to the second load for providing second direct current to the second load, the voltage of the first direct current being greater than the voltage of the second direct current.

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