Method of battery management, battery management system, battery system and electric device

Abstract

This application provides a battery management method, a battery management system, a battery system, and an electrical device, which can reduce the possibility of undervoltage or overvoltage during energy interaction. The method includes: acquiring the battery's first DC internal resistance, the allowable current corresponding to the maximum allowable power, the actual current at the current moment, and the actual voltage at the current moment; determining, based on the first DC internal resistance, the allowable current, the actual current, and the actual voltage, the predicted voltage of the battery when it interacts with the maximum allowable power at the next moment; determining, based on the predicted voltage and the maximum allowable power, the target allowable power of the battery when it interacts with the power at the current moment; and controlling the energy interaction between the battery and other devices based on the target allowable power.

Description

Technical Field

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

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

[0003] Therefore, improving battery performance is an urgent problem to be solved. Summary of the Invention

[0004] This application provides a battery management method, a battery management system, a battery system, and an electrical device, which can reduce the possibility of undervoltage or overvoltage in the battery during energy interaction.

[0005] In a first aspect, a battery management method is provided, the method comprising: acquiring a first DC internal resistance of the battery, a permissible current corresponding to a maximum permissible power, an actual current at the current moment, and an actual voltage at the current moment; determining a predicted voltage of the battery at the next moment when it performs energy interaction at the maximum permissible power, based on the first DC internal resistance, the permissible current, the actual current, and the actual voltage; determining a target permissible power of the battery at the current moment when it performs energy interaction, based on the predicted voltage and the maximum permissible power; and controlling the battery to perform energy interaction with other devices based on the target permissible power.

[0006] In this embodiment, the predicted voltage of the battery at the next moment is determined based on the battery's DC internal resistance, allowable current, actual current, and actual voltage. This method not only requires less computation but is also simpler to implement. Furthermore, the determined predicted voltage is the voltage at which the battery performs energy interaction at its maximum allowable power. Then, based on the determined predicted voltage and the maximum allowable power, the target allowable power for energy interaction at the current moment is determined. That is, power control at the current moment is performed using the predicted voltage corresponding to the maximum allowable power, which can reduce the possibility of undervoltage or overvoltage in the battery during energy interaction.

[0007] In some possible implementations, determining the predicted voltage of the battery at the next moment when it performs energy interaction with the maximum allowed power, based on the first DC internal resistance, the allowed current, the actual current, and the actual voltage, includes: updating the first DC internal resistance to obtain a second DC internal resistance; and determining the predicted voltage based on the second DC internal resistance, the allowed current, the actual current, and the actual voltage.

[0008] This technical solution updates the first DC internal resistance, making the DC internal resistance used to determine the predicted voltage more accurate. As a result, the accuracy of the target allowable power obtained based on the predicted voltage will also be higher, thereby further reducing the possibility of over-discharge during battery discharge or overcharge during recharge.

[0009] In some possible implementations, updating the first DC internal resistance to obtain a second DC internal resistance includes: during the use of the battery, when the battery is under target operating conditions and the battery's state parameters are within a preset range, obtaining a third DC internal resistance of the battery; determining the degree of internal resistance aging of the battery based on the third DC internal resistance and a third initial DC internal resistance, wherein the state parameters of the battery corresponding to the third DC internal resistance and the third initial DC internal resistance are the same; and determining the second DC internal resistance based on the degree of internal resistance aging and the first DC internal resistance.

[0010] This technical solution calculates the DC internal resistance only when the battery's state parameters are within a preset range during battery use. Therefore, during the update of the first DC internal resistance, a DC internal resistance is obtained while the battery's state parameters are within the preset range. Based on this DC internal resistance and its corresponding initial DC internal resistance, the battery's internal resistance aging degree is determined. Thus, the updated value of the first DC internal resistance is obtained based on the internal resistance aging degree and the first DC internal resistance. In this way, the updated value of the first DC internal resistance, i.e., the second DC internal resistance, matches the current internal resistance aging degree of the battery, resulting in higher accuracy of the second DC internal resistance. This further reduces the possibility of over-discharge during discharge or overcharge during recharge.

[0011] In some possible implementations, when the energy interaction includes discharging, the target operating condition includes the battery being left idle for a first preset time, and then continuously discharging at a constant rate for a second preset time; when the energy interaction includes recharging, the target operating condition includes the battery being left idle for a third preset time, and then continuously recharging at a constant rate for a fourth preset time.

[0012] This technical solution involves allowing the battery to rest for a certain period before continuously discharging or recharging it at a constant rate. This not only removes polarization by allowing the battery to rest, reducing its impact on the third DC internal resistance, but also ensures that the method for determining the third DC internal resistance is the same as the method for obtaining the DC internal resistance in the DC internal resistance map table. This further improves the accuracy of determining the second DC internal resistance.

[0013] In some possible implementations, determining the target allowable power of the battery when it performs energy interaction at the current moment based on the predicted voltage and the maximum allowable power includes: determining the target allowable power based on the predicted voltage, the maximum allowable power, and the battery's cutoff voltage.

[0014] In addition to predicting the voltage and maximum allowable power, this technical solution also determines the target allowable power based on the battery's cutoff voltage. That is, it determines the target allowable power based on more parameters, which makes the accuracy of the determined target allowable power higher. This can further reduce the possibility of overvoltage or undervoltage problems in the battery during energy interaction.

[0015] In some possible implementations, the energy interaction includes discharge, the maximum allowable power is the maximum allowable discharge power, the target allowable power is the target allowable discharge power, the cutoff voltage is the discharge cutoff voltage, and determining the target allowable power based on the predicted voltage, the maximum allowable power, and the battery's cutoff voltage includes: when the predicted voltage is less than or equal to a first preset voltage, reducing the maximum allowable discharge power, and the power obtained after reducing the maximum allowable discharge power is the target allowable discharge power; when the predicted voltage is greater than or equal to a second preset voltage, determining the maximum allowable discharge power as the target allowable discharge power; wherein the first preset voltage and the second preset voltage are determined based on the discharge cutoff voltage.

[0016] If the predicted voltage is less than or equal to the first preset voltage, it indicates a low predicted voltage and a risk of undervoltage in the next moment. In this case, the maximum allowable discharge power is reduced, and the power obtained after reducing the maximum allowable discharge power is determined as the target allowable discharge power. This reduces the actual discharge power of the battery, thereby lowering the possibility of undervoltage. If the predicted voltage is greater than or equal to the second preset voltage, it indicates a high predicted voltage and a low possibility of undervoltage in the next moment. Therefore, there is no need to limit the maximum allowable discharge power. Thus, determining the maximum allowable discharge power as the target allowable discharge power effectively improves the battery's discharge efficiency.

[0017] In some possible implementations, the first preset voltage is the sum of the discharge cutoff voltage and the first voltage, and the second preset voltage is the sum of the discharge cutoff voltage and the second voltage.

[0018] This technical solution intervenes with power limiting before the predicted voltage reaches the discharge cutoff voltage (i.e., before the predicted voltage reaches the discharge cutoff voltage), reducing the maximum allowable discharge power. This reduces the probability of over-discharge and subsequent undervoltage. Furthermore, when the predicted voltage is greater than or equal to the discharge cutoff voltage and the preset voltage, the maximum allowable discharge power is set as the target allowable discharge power. This reduces the impact of the battery's "phantom charge" phenomenon, further lowering the likelihood of over-discharge.

[0019] In some possible implementations, the first voltage is lower than the second voltage. Setting the first voltage to be lower than the second voltage can further reduce the impact of the battery's virtual charge phenomenon, thereby effectively reducing the possibility of over-discharge. Furthermore, having an interval between the first and second voltages, such as a 50mV interval, can reduce the probability of repeatedly triggering the strategy of adjusting the allowable discharge power, thereby improving discharge efficiency.

[0020] In some possible implementations, the energy interaction includes recharge, the maximum allowable power is the maximum allowable recharge power, the target allowable power is the target allowable recharge power, the cutoff voltage is the full charge cutoff voltage, and determining the target allowable power based on the predicted voltage, the maximum allowable power, and the battery's cutoff voltage includes: reducing the maximum allowable recharge power to obtain the target allowable power when the predicted voltage is greater than or equal to a third preset voltage; and determining the maximum allowable recharge power as the target allowable power when the predicted voltage is less than or equal to a fourth preset voltage; wherein the third preset voltage and the fourth preset voltage are determined based on the full charge cutoff voltage.

[0021] If the predicted voltage is greater than or equal to the third preset voltage, it indicates a high predicted voltage and a risk of overvoltage in the next moment. In this case, reducing the maximum allowable recharge power reduces the actual recharge power of the battery, thus lowering the possibility of overvoltage. If the predicted voltage is less than or equal to the fourth preset voltage, it indicates a low predicted voltage and a lower possibility of overvoltage in the next moment, so there is no need to limit the maximum allowable recharge power. Therefore, setting the maximum allowable recharge power as the target allowable recharge power can effectively improve the efficiency of battery recharge.

[0022] In some possible implementations, the third preset voltage is the difference between the full charge cutoff voltage and the third voltage, and the fourth preset voltage is the sum of the full charge cutoff voltage and the fourth voltage.

[0023] This technical solution sets the third preset voltage to the difference between the full-charge cutoff voltage and the third voltage. This means that power limiting is implemented before the predicted voltage reaches the full-charge cutoff voltage, thus reducing the maximum allowable recharge power and lowering the probability of battery overvoltage. Furthermore, setting the fourth preset voltage to the difference between the full-charge cutoff voltage and the fourth voltage reduces overvoltage caused by further increases in the battery's polarization voltage. It also reduces dendrite formation to some extent, effectively improving battery performance.

[0024] In some possible implementations, the third voltage is lower than the fourth voltage. Setting the third voltage to be lower than the fourth voltage, i.e., having an interval between the third and fourth voltages, such as an interval of 50mV, can reduce the likelihood of the battery repeatedly triggering the power limiting strategy, thereby improving recharge efficiency.

[0025] In some possible implementations, determining the predicted voltage of the battery at the next moment when it performs energy interaction at the maximum allowed power, based on the first DC internal resistance, the allowable current, the actual current, and the actual voltage, includes: determining the voltage change of the battery between the current moment and the next moment based on the allowable current, the actual current of the battery at the current moment, and the first DC internal resistance; and determining the predicted voltage based on the voltage change and the actual voltage of the battery at the current moment.

[0026] This technical solution first determines the voltage change based on the allowable current, the actual current, and the DCR, and then determines the predicted voltage based on the voltage change and the actual voltage at the current moment. This not only results in a high accuracy of the predicted voltage, but also simplifies the calculation and increases the computational efficiency.

[0027] Secondly, a battery management system is provided, comprising: a control unit, configured to acquire a first DC internal resistance of the battery, a permissible current corresponding to the maximum permissible power, an actual current at the current moment, and an actual voltage at the current moment, and to determine a predicted voltage of the battery at the next moment when it performs energy interaction at the maximum permissible power, based on the first DC internal resistance, the permissible current, the actual current, and the actual voltage; the control unit is further configured to determine a target permissible power of the battery at the current moment when it performs energy interaction, based on the predicted voltage and the maximum permissible power, and to control the battery to perform energy interaction with other devices based on the target permissible power.

[0028] Thirdly, a battery management system is provided, including a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call the computer program to execute the methods in the first aspect or its various implementations.

[0029] Fourthly, a battery system is provided, comprising: a battery; and a battery management system for performing the methods described in the first aspect or their respective implementations to manage the battery.

[0030] Fifthly, an electrical device is provided, comprising: a first load; a second load; and a battery system according to the fourth aspect above, wherein the battery system is connected to the first load for providing a first direct current to the first load, and / or the battery system is connected to the second load for providing a second direct current to the second load, wherein the voltage of the first direct current is greater than a voltage threshold, and the voltage of the second direct current is less than a voltage threshold.

[0031] In a sixth aspect, an electrical device is provided, comprising: a first load; and a battery system according to the fourth aspect above, the battery system being connected to the first load for providing a first direct current to the first load, the voltage of the first direct current being greater than a voltage threshold.

[0032] In a seventh aspect, a computer-readable storage medium is provided for storing a computer program that causes a computer to perform the methods described in the first aspect or its implementations.

[0033] Eighthly, a computer program product is provided, comprising: computer program instructions, which, when executed by a computer, cause the computer to perform the method described in the first aspect or its various implementations. Attached Figure Description

[0034] Figure 1 A schematic flowchart of a battery management method according to an embodiment of this application is shown.

[0035] Figure 2 A schematic flowchart illustrating another battery management method according to an embodiment of this application is shown.

[0036] Figure 3 A schematic flowchart illustrating another battery management method according to an embodiment of this application is shown.

[0037] Figure 4 A schematic block diagram of a first battery management system according to an embodiment of this application is shown.

[0038] Figure 5 A schematic block diagram of a second battery management system according to an embodiment of this application is shown.

[0039] Figure 6 A schematic block diagram of a first battery system according to an embodiment of this application is shown.

[0040] Figure 7A schematic block diagram of an electrical device according to an embodiment of this application is shown. Detailed Implementation

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

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

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

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

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

[0046] In the field of new energy, batteries are the primary power source for electrical devices such as electric vehicles, ships, and spacecraft, and their importance is self-evident. During battery discharge, a shift from low to high current may occur, such as during sudden acceleration, full-throttle overtaking, or starting from a stop at a red light. This can cause a drop in battery voltage, posing a risk of undervoltage. Similarly, during recharging, a shift from low to high current may occur, such as when a device suddenly enters emergency braking or strong regenerative braking mode from constant speed, or when coasting and then applying the brakes. This can cause a sharp rise in battery voltage, posing a risk of overvoltage. When a device decelerates or coasts, its kinetic energy can drive an electric motor to reverse, turning it into a generator and converting some of the kinetic energy into electrical energy, which is then stored in the battery. This process is called recharging.

[0047] In view of this, embodiments of this application provide a battery management method, the method comprising: obtaining a first DC internal resistance of the battery, determining a predicted voltage of the battery at the next moment when it performs energy interaction at the maximum allowable power based on the first DC internal resistance, determining a target allowable power of the battery at the current moment when it performs energy interaction based on the predicted voltage and the maximum allowable power, and controlling the energy interaction between the battery and other devices based on the target allowable power.

[0048] This technical solution determines the battery's predicted voltage at the next moment based on the battery's DC internal resistance, requiring less computation. Furthermore, the determined predicted voltage is the voltage at which the battery performs energy interaction at its maximum allowable power. Then, based on the determined predicted voltage and the maximum allowable power, the target allowable power for energy interaction at the current moment is determined. That is, power control is performed using the predicted voltage corresponding to the maximum allowable power, which can reduce the possibility of undervoltage or overvoltage during energy interaction.

[0049] The technical solutions described in the embodiments of this application are applicable to various battery-powered devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, electric vehicles, ships, and spacecraft. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.

[0050] It should be understood that the technical solutions described in the embodiments of this application are not limited to the devices described above, but can also be applied to all devices that use batteries. However, for the sake of brevity, the following embodiments are all illustrated using electric vehicles as an example.

[0051] Regarding the type of battery, the battery in this application embodiment can be any type of battery, including but not limited to: lithium-ion batteries, lithium metal batteries, lithium-sulfur batteries, lead-acid batteries, nickel-metal hydride batteries, lithium-air batteries, sodium batteries, etc. For example, lithium-ion batteries can be ternary lithium batteries, lithium iron phosphate batteries, anode-free batteries (AFB) batteries, etc. Regarding the size of the battery, the battery in this application embodiment can be a battery module or a battery pack. In this application embodiment, the specific type and size of the battery are not specifically limited.

[0052] Multiple batteries can be connected in series, in parallel, or in a hybrid configuration of these methods. Hybrid connection refers to multiple batteries being connected in series and in parallel, and there are no special restrictions on this.

[0053] Furthermore, to intelligently manage and maintain the battery, prevent overcharging and over-discharging, and extend battery life, a battery management system (BMS) is generally included in the battery system. This BMS performs at least one of the following functions: battery status monitoring, status analysis, charge / discharge control, safety protection, thermal management, high-voltage power distribution, and information management. In addition, the BMS described in this application can also perform the functions of a controller in an electrical device, such as a vehicle control unit (VCU) or a motor control unit (MCU). This application does not impose any limitations on this.

[0054] Battery Management System (BMS) can be integrated into the battery as a controller. Alternatively, it can be integrated into electrical devices, such as vehicles or vehicle chassis. Furthermore, it can be integrated into charging systems, such as charging devices or battery swapping devices. Or, it can be deployed as control software on a server. The server can be a standalone physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery networks (CDNs), and big data and artificial intelligence platforms, such as vehicle-to-everything (V2X) cloud services and app backends.

[0055] Figure 1 A schematic flowchart of a battery management method 100 according to an embodiment of this application is shown. Method 100 may include at least some of the following. Method 100 may be executed by a BMS.

[0056] S110: Obtain the battery's first DC internal resistance (DCR), the allowable current corresponding to the maximum allowable power, the actual current at the current moment, and the actual voltage at the current moment.

[0057] S120: Based on the first DCR, allowable current, actual current and actual voltage, determine the predicted voltage of the battery when it performs energy interaction at the maximum allowable power at the next moment.

[0058] S130: Determine the target allowable power of the battery when it performs energy interaction at the current moment, based on the predicted voltage and the maximum allowable power.

[0059] S140: Controls energy interaction between the battery and other devices based on the target allowable power.

[0060] In this embodiment, the predicted voltage of the battery at the next moment is determined based on the battery's DC internal resistance, allowable current, actual current, and actual voltage. This method not only requires less computation but is also simpler to implement. Furthermore, the determined predicted voltage is the voltage at which the battery performs energy interaction at its maximum allowable power. Then, based on the determined predicted voltage and the maximum allowable power, the target allowable power for energy interaction at the current moment is determined. That is, power control at the current moment is performed using the predicted voltage corresponding to the maximum allowable power, which can reduce the possibility of undervoltage or overvoltage in the battery during energy interaction.

[0061] Energy interaction may include discharging or recharging. If energy interaction includes discharging, the maximum allowable power is the maximum allowable discharge power, the allowable current is the allowable discharge current, and the target allowable power is the target allowable discharge power; if energy interaction includes recharging, the maximum allowable power is the maximum allowable recharge power, the allowable current is the allowable recharge current, and the target allowable power is the target allowable recharge power.

[0062] Maximum allowable power can be understood as the battery's static capacity, representing its maximum capability. Target allowable power can be understood as the battery's dynamic capacity, representing the power output during actual energy interaction. The target allowable power may differ at different times. The target allowable power is typically less than or equal to the maximum allowable power. For example, if energy interaction includes discharge, then the maximum allowable power is the battery's static discharge capacity, representing its maximum discharge capacity, while the target allowable power is the battery's dynamic discharge capacity, representing the power output during actual discharge.

[0063] Optionally, the maximum allowable power can be determined based on the battery's state parameters, which may include, but are not limited to, at least one of the following: temperature, current, voltage, state of charge (SOC), and state of equilibrium (SOH). The battery's state parameters can be monitored in real time, or they can be acquired at preset time intervals, such as 1ms, 50ms, 100ms, or 1s. For example, the battery's current and temperature can be acquired, and then the battery's SOC can be determined based on the current and temperature. Finally, the maximum allowable power can be determined based on the battery's SOC and a power meter.

[0064] The first DCR can be the DCR when the battery just comes off the production line. At this time, it can be understood that the state of health (SOH) of the battery is 100%, and the first DCR is the beginning of life (BOL) value.

[0065] Optionally, the first DCR can be obtained based on a pulse method. This involves applying a constant DC current for a preset duration to the power supply through a controllable load or power source, and collecting the voltage across the battery terminals before, during, and after the pulse application. The preset duration can be, for example, 50 milliseconds (ms), 100 ms, 500 ms, 1 second (s), 2 seconds, 5 seconds, or 10 seconds. The first DCR is then determined according to the following formula:

[0066] (1)

[0067] in, For the first DCR, This is the first voltage value. This is the second voltage value. This represents the amplitude of the pulse current.

[0068] The first DCR can be data obtained through prior testing and stored on the BMS in the form of a DCR characteristic table (i.e., a DCR map table), or it can be stored in the cloud as a DCR map table, which the BMS can access by communicating with the cloud. In the DCR map table, the DCR may differ for different SOCs and different temperatures.

[0069] It should be noted that the DCR map is obtained under the battery depolarized state and is related to the battery's own energy interaction performance. The DCR map is used to obtain the DCR in the BOL state and is the initial value of DCR.

[0070] Due to differences in manufacturing processes, the DCR (Discharge Rate) of different battery cells may vary. Therefore, the first DCR of the battery in this embodiment can be understood as the first DCR of each battery cell in the battery.

[0071] Once the first DCR is determined, the predicted voltage when the battery interacts with energy at its maximum allowable power can be determined.

[0072] Specifically, the allowable current of the battery can be determined based on the maximum allowable power. Then, the voltage change between the current moment and the next moment can be determined based on the allowable current, the actual current of the battery at the current moment, and the first DCR. Finally, the predicted voltage can be determined based on the voltage change and the actual voltage at the current moment.

[0073] This technical solution first determines the voltage change based on the allowable current, the actual current, and the DCR, and then determines the predicted voltage based on the voltage change and the actual voltage at the current moment. This not only results in a high accuracy of the predicted voltage, but also simplifies the calculation and increases the computational efficiency.

[0074] When the energy interaction is discharge, the predicted voltage can satisfy the following formula:

[0075] (2)

[0076] Where U1 is the predicted voltage when the energy interaction is discharge. Energy interaction refers to the voltage change between the current moment and the next moment during discharge, i.e., the voltage drop, U. 01 For energy interaction, I represents the actual voltage at the current moment during discharge. 11 For the allowable discharge current, I 01 This represents the actual current at the current moment.

[0077] When the energy interaction is recharge, the predicted voltage can satisfy the following formula:

[0078] (3)

[0079] Where U2 is the predicted voltage when the energy interaction is recharge. For energy interaction, U represents the voltage change between the current moment and the next moment during recharging, i.e., voltage rise. 02 For energy interaction, I represents the actual voltage at the current moment during recharging. 12 To allow for recharge current, I 02 This represents the actual current at the current moment.

[0080] It should be noted that, in the embodiments of this application, the predicted voltage can be the predicted voltage of each battery cell.

[0081] After determining the predicted voltage, the target allowable power of the battery when it performs energy interaction at the next moment can be determined based on the predicted voltage and the maximum allowable power.

[0082] In some embodiments, such as Figure 2 As shown, S130 may specifically include S131: determining the target allowable power based on the predicted voltage, the maximum allowable power, and the battery cutoff voltage.

[0083] In addition to predicting the voltage and maximum allowable power, this technical solution also determines the target allowable power based on the battery's cutoff voltage. That is, it determines the target allowable power based on more parameters, which makes the accuracy of the determined target allowable power higher. This can further reduce the possibility of overvoltage or undervoltage problems in the battery during energy interaction.

[0084] In the case where energy interaction includes discharge, the cutoff voltage is the discharge cutoff voltage, the target allowable power is the target allowable discharge power, and the predicted voltage can be the minimum value among the predicted voltages of all battery cells. In the case where energy interaction includes recharge, the cutoff voltage includes the full charge cutoff voltage, the target allowable power is the target allowable recharge power, and the predicted voltage can be the maximum value among the predicted voltages of all battery cells.

[0085] The discharge cutoff voltage refers to the lowest safe voltage at which a battery should stop discharging when its voltage drops to a specified value during the discharge process. The discharge cutoff voltage can be related to factors such as the battery's chemical system, temperature, discharge rate, degree of aging, and manufacturer strategies. For example, the discharge cutoff voltage of a ternary lithium battery differs from that of a lithium iron phosphate battery. The full charge cutoff voltage is the highest voltage a battery is allowed to reach during recharge; it is also related to parameters such as the battery's chemical system.

[0086] In cases where energy interaction includes discharge, if the predicted voltage is less than or equal to a first preset voltage, the maximum allowable discharge power can be reduced, and the power obtained after reducing the maximum allowable discharge power is the target allowable discharge power. If the predicted voltage is greater than or equal to a second preset voltage, the maximum allowable discharge power can be determined as the target allowable discharge power. The first and second preset voltages are determined based on the discharge cutoff voltage.

[0087] If the predicted voltage is less than or equal to the first preset voltage, it indicates that the predicted voltage is low and there is a risk of undervoltage in the next moment. At this time, the maximum allowable discharge power is reduced, and the power obtained after reducing the maximum allowable discharge power is determined as the target allowable discharge power. That is, the actual discharge power of the battery is reduced, thus reducing the possibility of undervoltage in the battery.

[0088] If the predicted voltage is greater than or equal to the second preset voltage, it indicates that the predicted voltage is relatively high, and the possibility of the battery experiencing undervoltage in the next moment is low, so there is no need to limit the maximum allowable discharge power. Therefore, setting the maximum allowable discharge power as the target allowable discharge power can effectively improve the battery discharge efficiency.

[0089] As an example, the first preset voltage and the second preset voltage can be the discharge cutoff voltage of the battery.

[0090] For example, the maximum allowable discharge power is 100 kW, and the discharge cutoff voltage is 2.6 volts (V). If the predicted voltage at the next moment is 2V, the maximum allowable discharge power can be reduced, for example, to 70 kW, then the target allowable discharge power at the current moment is 70 kW. If the predicted voltage at the next moment is 3V, which is greater than the discharge cutoff voltage, then the target allowable discharge power at the current moment is 100 kW.

[0091] During dynamic battery discharge, due to instantaneous polarization and cumulative polarization, undervoltage may still occur even when the battery is not completely discharged (i.e., the State of Charge (SOC) is still greater than 0), as the voltage drops rapidly. This can damage battery life and affect the use of electrical devices. Therefore, power limiting can be implemented before the predicted voltage reaches the discharge cutoff voltage to reduce the possibility of undervoltage.

[0092] Furthermore, after the battery stops discharging, a voltage rebound phenomenon may occur, meaning the battery's terminal voltage may gradually rise to a relatively stable, higher value after discharge stops. For example, if the battery voltage is 2.6V before discharge and drops to 2.3V after discharge, it may rebound to 2.5V or even 2.6V after a period of time. However, although the battery voltage rebounds to 2.5V, this 2.5V may be a "phantom voltage" phenomenon; although it appears as 2.5V, the battery may not actually function at 2.5V. To reduce the impact of phantom voltage, the maximum allowable discharge power can be determined as the target allowable discharge power only when the predicted voltage exceeds the discharge cutoff voltage by a certain degree.

[0093] Therefore, as another example, the first preset voltage can be the sum of the discharge cutoff voltage and the first voltage, and the second preset voltage can be the sum of the discharge cutoff voltage and the second voltage.

[0094] This technical solution intervenes with power limiting before the predicted voltage reaches the discharge cutoff voltage (i.e., before the predicted voltage reaches the discharge cutoff voltage), reducing the maximum allowable discharge power. This reduces the probability of over-discharge and subsequent undervoltage. Furthermore, when the predicted voltage is greater than or equal to the discharge cutoff voltage and the preset voltage, the maximum allowable discharge power is set as the target allowable discharge power. This reduces the impact of the battery's "phantom charge" phenomenon, further lowering the likelihood of over-discharge.

[0095] Optionally, the first voltage and the second voltage can be determined based on empirical parameters, the first DCR, the battery's discharge characteristic map (i.e., discharge map), or other parameters.

[0096] The first voltage can be the same as the second voltage. For example, the first voltage and the second voltage can both be 300mV, or both can be 400mV.

[0097] Alternatively, the first voltage can differ from the second voltage. For example, the first voltage can be greater than the second voltage, or it can be less than the second voltage, such as a first voltage of 300mV and a second voltage of 350mV. Setting the first voltage to be less than the second voltage can further reduce the impact of the battery's phantom charge phenomenon, thereby effectively reducing the possibility of over-discharge. Furthermore, having an interval between the first and second voltages, such as a 50mV interval, can reduce the probability of repeatedly triggering the strategy of adjusting the allowable discharge power, thereby improving discharge efficiency.

[0098] When the predicted voltage is less than or equal to the first preset voltage, the specific amount by which the maximum allowable discharge power is reduced can be determined based on experience, the battery's attribute parameters, or the battery's application scenario.

[0099] In some embodiments, as long as the predicted voltage is less than the first preset voltage, the adjustment value of the maximum allowable discharge power can be the same, that is, the final target allowable discharge power is the same.

[0100] For example, if the maximum allowable discharge power is 100kW, the first preset voltage is 3.3V, and the predicted voltage is 3.2V, reducing the maximum allowable discharge power by 20% will result in a target allowable discharge power of 80kW. Similarly, if the predicted voltage is 3V, reducing the maximum allowable discharge power by 20% will also result in a target allowable discharge power of 80kW.

[0101] In other embodiments, the predicted voltage can be divided into multiple levels, each with a different adjustment value. In other words, a target adjustment value for the maximum allowable discharge power can be determined based on the predicted voltage and multiple first correspondences between the predicted voltage and the adjustment value. Then, based on the target adjustment value, the maximum allowable discharge power is reduced to the target allowable discharge power.

[0102] This technical solution has multiple correspondences between the predicted voltage and the adjustment value, which enables step-by-step power control, making the power adjustment more precise. This not only ensures discharge efficiency but also reduces the possibility of over-discharge of the battery.

[0103] Optionally, multiple first correspondences can be determined based on the battery's attribute parameters.

[0104] For example, assuming the first preset voltage is 3.3V, several first correspondences include: when the predicted voltage is less than 3.3V but greater than or equal to 3V, the adjustment value is 40%; when the predicted voltage is less than 3V but greater than or equal to 2.8V, the adjustment value is 60%; and when the predicted voltage is less than 2.8V, the adjustment value is 80%. Here, an adjustment value of a% indicates a reduction of a% in the maximum allowable discharge power.

[0105] If the maximum allowable discharge power is 100KW and the predicted voltage is 3.1V, the target adjustment value is 40%, and the target allowable discharge power is 60KW; if the predicted voltage is 2.6V, the target adjustment value is 80%, and the target allowable discharge power is 20KW.

[0106] In the case of energy interaction protection recharge, if the predicted voltage is greater than or equal to the third preset voltage, the maximum allowable recharge power can be reduced, and the power obtained after reducing the maximum allowable recharge power is the target allowable recharge power. If the predicted voltage is less than or equal to the fourth preset voltage, the maximum allowable recharge power can be determined as the target allowable recharge power. The third and fourth preset voltages are determined based on the full-charge cutoff voltage.

[0107] If the predicted voltage is greater than or equal to the third preset voltage, it indicates that the predicted voltage is too high and there is a risk of overvoltage in the next moment. At this time, reducing the maximum allowable recharge power reduces the actual recharge power of the battery, thus reducing the possibility of overvoltage in the battery.

[0108] If the predicted voltage is less than or equal to the fourth preset voltage, it indicates that the predicted voltage is low at this time, and the possibility of overvoltage in the battery at the next moment is low, so there is no need to limit the maximum allowable recharge power. Therefore, setting the maximum allowable recharge power as the target allowable recharge power can effectively improve the efficiency of battery recharge.

[0109] As an example, the third and fourth preset voltages can be the battery's full charge cutoff voltage.

[0110] For example, the maximum allowable recharge power is 100kW, and the full charge cutoff voltage is 2.6V. If the predicted voltage at the next moment is 2.8V, the maximum allowable recharge power can be reduced, for example, to 70kW, then the target allowable recharge power at the current moment is 70kW. If the predicted voltage at the next moment is 2.5V, which is greater than the recharge cutoff voltage, then the target allowable recharge power at the current moment is 100kW.

[0111] To prevent overvoltage during recharge from limiting the power of electrical devices and affecting user experience, power limiting can be implemented in advance before the predicted voltage reaches the full charge cutoff voltage, thereby reducing the possibility of overvoltage.

[0112] Therefore, as another example, the third preset voltage can be the difference between the full charge cutoff voltage and the third voltage, and the fourth preset voltage can be the difference between the full charge cutoff voltage and the fourth voltage.

[0113] This technical solution sets the third preset voltage to the difference between the full-charge cutoff voltage and the third voltage. This means that power limiting is implemented before the predicted voltage reaches the full-charge cutoff voltage, thus reducing the maximum allowable recharge power and lowering the probability of battery overvoltage. Furthermore, setting the fourth preset voltage to the difference between the full-charge cutoff voltage and the fourth voltage reduces overvoltage caused by further increases in the battery's polarization voltage. It also reduces dendrite formation to some extent, effectively improving battery performance.

[0114] Optionally, the third and fourth voltages can be determined based on empirical parameters, the first DCR, the battery's recharge characteristic map (i.e., the recharge map), or other parameters.

[0115] The third and fourth voltages can be the same; for example, both the third and fourth voltages can be 300mV or 400mV.

[0116] Alternatively, the third and fourth voltages can be different. For example, the third voltage can be greater than the fourth voltage, or it can be less than the fourth voltage, such as a third voltage of 300mV and a fourth voltage of 350mV. Setting the third voltage to be less than the fourth voltage, i.e., having an interval between the third and fourth voltages, such as a 50mV interval, can reduce the likelihood of the battery repeatedly triggering the power limiting strategy, thereby improving recharge efficiency.

[0117] When it is necessary to limit the maximum allowable recharge power, the specific amount to be reduced can be determined based on experience, battery properties, or the application scenario of the battery.

[0118] In some embodiments, if it is necessary to limit the maximum allowable recharge power, the adjustment value of the maximum allowable recharge power can be the same for all cases. In other words, the final target allowable recharge power is the same.

[0119] For example, if the maximum allowable recharge power is 100kW and the third preset voltage is 3.5V, and the predicted voltage is 3.8V, then the maximum allowable recharge power will be reduced by 20%, and the target allowable recharge power will be 80kW. If the predicted voltage is 4V, the maximum allowable recharge power will also be reduced by 20%, and the target allowable recharge power will also be 80kW.

[0120] In other embodiments, the predicted voltage can be divided into multiple levels, with different adjustment values ​​corresponding to different levels. In this case, a target adjustment value can be determined based on the predicted voltage and multiple second correspondences between the predicted voltage and the power adjustment value. Then, the maximum allowable recharge power is reduced by the target adjustment value to obtain the target allowable recharge power.

[0121] This technical solution predicts multiple correspondences between voltage and power adjustment values, enabling step-by-step power control and making power adjustment more precise. This not only ensures recharge efficiency but also effectively reduces the possibility of battery overvoltage.

[0122] For example, when the minimum single-cell voltage is greater than 3.3V and less than or equal to 3.6V, the power adjustment value is 40%; when the minimum single-cell voltage is greater than 3.6V and less than or equal to 4V, the power adjustment value is 60%; and when the minimum single-cell voltage is greater than 4V, the power adjustment value is 80%. Here, the adjustment value of a% indicates a reduction of a% in the maximum allowable recharge power.

[0123] Assuming the third preset voltage is 3.3V, the maximum allowable recharge power is 100KW, and the predicted voltage is 3.5V, then the target adjustment value is 40%, and the target allowable recharge power is 60KW; if the predicted voltage is 4.1V, then the target adjustment value is 80%, and the target allowable recharge power is 20KW.

[0124] Once the target allowable power is determined, energy interaction between the battery and other devices can be controlled based on this target allowable power. The power at which the battery interacts with other devices at the current moment can be less than or equal to the target allowable power.

[0125] The above description refers to the first DCR as the BOL value. During actual battery discharge, the DCR increases with aging. To make the obtained predicted voltage more accurate, in some embodiments, such as... Figure 3 As shown, S120 may specifically include: S121, updating the first DCR to obtain the second DCR; S122, determining the predicted voltage of the battery when it performs energy interaction at the maximum allowable power at the next moment based on the second DCR.

[0126] This technical solution updates the first DCR, making the DCR used to determine the predicted voltage more accurate. This results in higher accuracy of the target allowable power obtained based on the predicted voltage, thereby further reducing the possibility of over-discharge during battery discharge or overcharge during recharge.

[0127] Optionally, a second DCR value can be obtained during battery use. The second DCR can be the end-of-life (EOL) value.

[0128] Normally, DCR can only be calculated online when the battery's state-of-the-art (SOC) parameters are within a preset range. This preset range can include a SOC between 35% and 65%, such as 40%, 50%, 55%, or 60%. Furthermore, since DCR is less affected by current and rate at room temperature, the preset range can also include a battery temperature within a normal range, such as 18°C ​​to 25°C, such as 19°C, 20°C, 21°C, 22°C, 23°C, or 24°C.

[0129] Therefore, updating the first DCR to obtain the second DCR can specifically include: during battery use, when the battery's state parameters are within a preset range, obtaining the battery's third DCR, determining the battery's internal resistance aging degree based on the first DCR and the third initial DCR, and then determining the second DCR based on the internal resistance aging degree and the first DCR.

[0130] The third DCR and the third initial DCR correspond to the same battery state parameters. For example, both the third DCR and the third initial DCR were obtained at a battery SOC of 50% and a temperature of 25°C. The third initial DCR was obtained by querying the DCR map table.

[0131] This technical solution calculates the Discharge Rate (DCR) only when the battery's state parameters are within a preset range during battery use. Therefore, during the update of the first DCR, a DCR is obtained while the battery's state parameters are within the preset range. Based on this DCR and its corresponding initial DCR, the battery's internal resistance aging level is determined. Thus, the updated value of the first DCR is obtained based on the internal resistance aging level and the first DCR. In this way, the updated value of the first DCR, i.e., the second DCR, matches the battery's current internal resistance aging level, resulting in a higher accuracy of the second DCR. This further reduces the possibility of over-discharge during discharge or overcharge during recharge.

[0132] The degree of aging of internal resistance can be represented by SOHR.

[0133] Optionally, if the battery's state parameters are within a preset range, the battery voltage at two different times can be obtained during the continuous discharge or recharge process at a constant rate, and then the third DCR can be obtained through formula (1).

[0134] Optionally, a third DCR can be obtained under any operating condition.

[0135] Optionally, a third DCR can be obtained under a target operating condition. For example, the target operating condition can be the same as the condition under which the first DCR was obtained. In other words, the third DCR can be obtained when the battery is under the target operating condition and the battery's state parameters are within a preset range.

[0136] Since the first DCR is obtained through the pulse method, the target operating condition can include: continuous energy interaction at a constant rate. That is, when the energy interaction includes discharging, the target operating condition can include the battery continuously discharging at a constant rate for a second preset duration; when the energy interaction includes recharging, the target operating condition can include the battery continuously recharging at a constant rate for a fourth preset duration.

[0137] The second preset duration can be the same as or different from the fourth preset duration. Optionally, the second preset duration can be in the range of 1s-5s, such as 2s, 3s, or 4s. Similarly, the fourth preset duration can also be in the range of 1s-5s, such as 2s, 3s, or 4s.

[0138] It should be noted that during battery use, it is difficult for the battery to continuously discharge or recharge at a constant rate. Therefore, in this embodiment, the second preset duration of continuous discharge at a constant rate can be understood as: the difference between the discharge rates of the battery within the second preset duration is less than the discharge rate change threshold, that is, the change in the battery's discharge rate is small within the second preset duration. Similarly, the fourth preset duration of continuous recharging at a constant rate can be understood as: the difference between the recharge rates of the battery within the fourth preset duration is less than the recharge rate change threshold, that is, the change in the battery's recharge rate is small within the fourth preset duration.

[0139] Considering that batteries typically exhibit polarization, failure to depolarize will result in a higher third DCR value. Therefore, in some embodiments, the battery can be allowed to rest for a certain period before continuous energy interaction at a constant rate. In other words, when energy interaction includes discharging, the target operating condition may include allowing the battery to rest for a first preset period, followed by continuous discharging at a constant rate for a second preset period; when energy interaction includes recharging, the target operating condition may include allowing the battery to rest for a third preset period, followed by continuous recharging at a constant rate for a fourth preset period.

[0140] This technical solution involves allowing the battery to rest for a certain period before continuously discharging or recharging it at a constant rate. This not only removes polarization by allowing the battery to rest, reducing its impact on the third DCR, but also ensures that the method for determining the third DCR is the same as the method for obtaining the DCR in the DCR map table. This further improves the accuracy of the second DCR.

[0141] The first preset duration and the third preset duration can be the same or different. For example, the first preset duration can be less than or equal to 5 minutes (min), such as 4 min, 3 min, 2 min, 1 min, 30 s, etc., and the third preset duration can also be less than or equal to 5 minutes, such as 4 min, 3 min, 2 min, 1 min, 30 s, etc.

[0142] After obtaining the second DCR, the DCR map table can be updated based on the second DCR.

[0143] In the embodiments of this application, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0144] Furthermore, without conflict, the various embodiments and / or technical features described in this application can be arbitrarily combined with each other, and the resulting technical solutions should also fall within the protection scope of this application.

[0145] The battery management method of the embodiments of this application has been described in detail above. The battery management system of the embodiments of this application will be described below. It should be understood that the battery management system of the embodiments of this application can execute the battery management method of the embodiments of this application.

[0146] Figure 4 A schematic block diagram of a first battery management system 400 according to an embodiment of this application is shown. Figure 4 As shown, the first battery management system 400 includes:

[0147] The control unit 410 is used to acquire the first DC internal resistance of the battery, the allowable current corresponding to the maximum allowable power, the actual current at the current moment, and the actual voltage at the current moment, and to determine the predicted voltage of the battery when it performs energy interaction at the maximum allowable power at the next moment based on the first DC internal resistance, the allowable current, the actual current, and the actual voltage.

[0148] The control unit 410 is further configured to determine, based on the predicted voltage and the maximum allowable power, the target allowable power of the battery when performing energy interaction at the current moment, and control the battery to perform energy interaction with other devices based on the target allowable power.

[0149] Optionally, in this embodiment of the application, the control unit 410 is specifically configured to: update the first DC internal resistance to obtain a second DC internal resistance; and determine the predicted voltage based on the second DC internal resistance, the allowable current, the actual current, and the actual voltage.

[0150] Optionally, in this embodiment of the application, the control unit 410 is specifically configured to: during the use of the battery, when the battery is under target operating conditions and the state parameters of the battery are within a preset range, obtain the third DC internal resistance of the battery; determine the degree of aging of the battery's internal resistance based on the third DC internal resistance and the third initial DC internal resistance, wherein the state parameters of the battery corresponding to the third DC internal resistance and the third initial DC internal resistance are the same; and determine the second DC internal resistance based on the degree of aging of the internal resistance and the first DC internal resistance.

[0151] Optionally, in the embodiments of this application, when the energy interaction includes discharging, the target operating condition includes the battery being left idle for a first preset time, and then continuously discharging at a constant rate for a second preset time; when the energy interaction includes recharging, the target operating condition includes the battery being left idle for a third preset time, and then continuously recharging at a constant rate for a fourth preset time.

[0152] Optionally, in this embodiment of the application, the control unit 410 is specifically configured to: determine the target allowable power based on the predicted voltage, the maximum allowable power, and the cutoff voltage of the battery.

[0153] Optionally, in this embodiment, the energy interaction includes discharge, the maximum allowable power is the maximum allowable discharge power, the target allowable power is the target allowable discharge power, and the cutoff voltage is the discharge cutoff voltage. The control unit 410 is specifically configured to: reduce the maximum allowable discharge power when the predicted voltage is less than or equal to a first preset voltage, and the power obtained after reducing the maximum allowable discharge power is the target allowable discharge power; and determine the maximum allowable discharge power as the target allowable discharge power when the predicted voltage is greater than or equal to a second preset voltage; wherein the first preset voltage and the second preset voltage are determined based on the discharge cutoff voltage.

[0154] Optionally, in this embodiment of the application, the first preset voltage is the sum of the discharge cutoff voltage and the first voltage, and the second preset voltage is the sum of the discharge cutoff voltage and the second voltage.

[0155] Optionally, in this embodiment, the first voltage is less than the second voltage.

[0156] Optionally, in this embodiment, the energy interaction includes recharge, the maximum allowable power is the maximum allowable recharge power, the target allowable power is the target allowable recharge power, and the cutoff voltage is the full charge cutoff voltage. The control unit 410 is specifically configured to: reduce the maximum allowable recharge power to obtain the target allowable power when the predicted voltage is greater than or equal to a third preset voltage; and determine the maximum allowable recharge power as the target allowable power when the predicted voltage is less than or equal to a fourth preset voltage; wherein the third preset voltage and the fourth preset voltage are determined based on the full charge cutoff voltage.

[0157] Optionally, in this embodiment, the third preset voltage is the difference between the full charge cutoff voltage and the third voltage, and the fourth preset voltage is the sum of the full charge cutoff voltage and the fourth voltage.

[0158] Optionally, in this embodiment, the third voltage is less than the fourth voltage.

[0159] Optionally, in this embodiment of the application, the control unit 410 is specifically configured to: determine the voltage change of the battery between the current time and the next time based on the allowable current, the actual current and the first DCR; and determine the predicted voltage based on the voltage change and the actual voltage.

[0160] It should be understood that the first battery management system 400 can implement the corresponding operations in the battery management method 100, which will not be elaborated here for the sake of brevity.

[0161] Figure 5 This is a schematic diagram of the hardware structure of a second battery management system 500 according to an embodiment of this application. The second battery management system 500 includes a memory 510, a processor 520, a communication interface 530, and a bus 540. The memory 510, processor 520, and communication interface 530 are interconnected via the bus 540.

[0162] The memory 510 may be a read-only memory (ROM), a static storage device, or a random access memory (RAM). The memory 510 may store a program, and when the program stored in the memory 510 is executed by the processor 520, the processor 520 and the communication interface 530 are used to execute the various steps of the battery management method of the embodiments of this application.

[0163] The processor 520 may be a general-purpose central processing unit (CPU), microprocessor, application-specific integrated circuit (ASIC), graphics processing unit (GPU), or one or more integrated circuits, used to execute relevant programs to implement the functions required by the units in the second battery management system 500 of this application embodiment, or to execute the battery management method of this application embodiment.

[0164] The processor 520 can also be an integrated circuit chip with signal processing capabilities. In implementation, each step of the battery management method of this application embodiment can be completed by the integrated logic circuitry in the processor 520 or by software instructions.

[0165] The processor 520 described above can also be a general-purpose processor, a digital signal processor (DSP), an ASIC, a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly implemented by the hardware processor, or implemented by a combination of hardware and software modules in the processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory 510. The processor 520 reads the information in memory 510 and, in conjunction with its hardware, completes the functions required by the units included in the second battery management system 500 of the embodiments of this application, or executes the battery management method of the embodiments of this application.

[0166] The communication interface 530 uses a transceiver device, such as, but not limited to, a transceiver, to enable communication between the second battery management system 500 and other devices or communication networks.

[0167] Bus 540 may include a pathway for transmitting information between various components of the second battery management system 500 (e.g., memory 510, processor 520, communication interface 530).

[0168] It should be noted that although the above-described second battery management system 500 only shows a memory, processor, and communication interface, those skilled in the art should understand that in specific implementations, the second battery management system 500 may also include other devices necessary for normal operation. Furthermore, depending on specific needs, those skilled in the art should understand that the second battery management system 500 may also include hardware devices for implementing other additional functions. In addition, those skilled in the art should understand that the second battery management system 500 may only include the devices necessary for implementing the embodiments of this application, and may not necessarily include... Figure 7 All the devices shown.

[0169] like Figure 6 As shown in the figure, this application embodiment also provides a first battery system 600, which may include a battery 610 and a third battery management system 620, which can be used to manage the battery 610.

[0170] Optionally, the third battery management system 620 can be Figure 4The first battery management system 400 or Figure 5 The second battery management system 500.

[0171] Alternatively, when there are multiple batteries 610, none of the batteries 610 can output energy individually.

[0172] Optionally, battery 610 may include a first battery and a second battery. In this case, the first battery system 600 may include multiple independently configured energy zones, with the first battery and the second battery respectively located in different energy zones. This technical solution, where the first battery and the second battery are located in different energy zones, provides a redundant battery design. Thus, during the use of the electrical device, if one battery malfunctions, the other battery can continue to supply power to the device, allowing it to continue operating normally.

[0173] The first and second batteries can specifically be battery packs, battery modules, or battery collections formed by electrically connecting individual battery cells.

[0174] An energy zone is a portion of the first battery system 600 that can operate and be controlled independently. For example, each energy zone can be charged and discharged independently. Specifically, the energy zones can be divided according to the battery configuration within the first battery system 600. Optionally, when the first battery system 600 includes one or more battery packs, energy zones can be divided within each battery pack. The first battery and the second battery can be located in different energy zones within each battery pack, and partition beams can be provided between the energy zones to isolate them. Alternatively, when the first battery system 600 includes multiple battery packs, each battery pack can be considered as a single energy zone, forming multiple energy zones across the multiple battery packs.

[0175] The first battery and the second battery can be connected in series, or they can be connected in parallel.

[0176] This application does not specifically limit the types of the first battery and the second battery. The types of the first battery and the second battery may be the same or different. The battery types of the individual cells inside the first battery may be the same or different, and the battery types of the individual cells inside the second battery may be the same or different.

[0177] In some embodiments, the type of the first battery and the type of the second battery may differ, as long as the output of the first and second batteries meets the system requirements. For example, the first battery can be a power battery, and the second battery can be an energy battery. Alternatively, the first battery can be an energy battery, and the second battery can be a power battery. This technical solution sets the first and second batteries to be different types of batteries, enabling the battery system to meet different usage scenarios, thereby allowing the battery system to perform its function under more operating conditions.

[0178] Alternatively, the first and second batteries can be set to be of the same type. For example, both the first and second batteries can be energy-type batteries, or both can be power-type batteries.

[0179] like Figure 7 As shown in the figure, this application embodiment also provides an electrical device 700, which includes a first load 710, a second load 720, and a second battery system 730. The second battery system 730 is connected to the first load 710 and is used to provide a first direct current to the first load 710, and / or the second battery system 730 is connected to the second load 720 and is used to provide a second direct current to the second load 720. The voltage of the first direct current is greater than a voltage threshold, and the voltage of the second direct current is less than a voltage threshold.

[0180] In other words, the first load 710 is a high-voltage load, the second load 720 is a low-voltage load, and the second battery system 730 provides low-voltage power to the first load 710 and high-voltage power to the second load 720.

[0181] The second battery system 730 may be, for example, the first battery system 600 described above, and the electrical device may be an electric vehicle.

[0182] This application also provides an electrical device, which includes a first load and a battery system. The battery system is connected to the first load and is used to supply power to the first load.

[0183] Alternatively, the battery system can be Figure 6 The first battery system 600 in the system. The first load can be a high-voltage load.

[0184] This application also provides a computer-readable storage medium for storing a computer program for performing the methods described in the various embodiments of this application.

[0185] The aforementioned computer-readable storage medium may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0186] This application also provides a computer program product, which includes a computer program stored on a computer-readable storage medium. The computer program includes program instructions that, when executed by a computer, cause the computer to perform the above-described battery management method.

[0187] 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 battery management, characterized by, The method includes: Obtain the battery's first DC internal resistance, the allowable current corresponding to the maximum allowable power, the actual current at the current moment, and the actual voltage at the current moment; Based on the first DC internal resistance, the allowable current, the actual current, and the actual voltage, determine the predicted voltage of the battery when it performs energy interaction at the maximum allowable power at the next moment; Based on the predicted voltage and the maximum allowable power, determine the target allowable power of the battery when it performs energy interaction at the current moment; Based on the target allowable power, control the energy interaction between the battery and other devices; Wherein, the energy interaction includes the case of discharge, the maximum permissible power is the maximum permissible discharge power, the target permissible power is the target permissible discharge power, and determining the target permissible power of the battery when performing energy interaction at the current moment based on the predicted voltage and the maximum permissible power includes: When the predicted voltage is less than or equal to the first preset voltage, the maximum allowable discharge power is reduced, and the power obtained after reducing the maximum allowable discharge power is the target allowable discharge power. When the predicted voltage is greater than or equal to the second preset voltage, the maximum allowable discharge power is determined as the target allowable discharge power, wherein the first preset voltage and the second preset voltage are determined based on the discharge cutoff voltage of the battery; In the case of energy interaction including recharge, the maximum permissible power is the maximum permissible recharge power, and the target permissible power is the target permissible recharge power. Determining the target permissible power of the battery at the current moment for energy interaction based on the predicted voltage and the maximum permissible power includes: If the predicted voltage is greater than or equal to the third preset voltage, the maximum allowable recharge power is reduced to obtain the target allowable power; When the predicted voltage is less than or equal to the fourth preset voltage, the maximum allowable recharge power is determined as the target allowable power, wherein the third preset voltage and the fourth preset voltage are determined based on the full charge cutoff voltage of the battery.

2. The method of claim 1, wherein, The step of determining the predicted voltage of the battery at the next moment when it performs energy interaction at the maximum permissible power, based on the first DC internal resistance, the permissible current, the actual current, and the actual voltage, includes: The first DC internal resistance is updated to obtain the second DC internal resistance; The predicted voltage is determined based on the second DC internal resistance, the allowable current, the actual current, and the actual voltage.

3. The method according to claim 2, characterized in that, The step of updating the first DC internal resistance to obtain the second DC internal resistance includes: During the use of the battery, when the battery is under target operating conditions and the battery's state parameters are within a preset range, the third DC internal resistance of the battery is obtained. The degree of aging of the battery's internal resistance is determined based on the third DC internal resistance and the third initial DC internal resistance. The state parameters of the battery corresponding to the third DC internal resistance and the third initial DC internal resistance are the same. The second DC internal resistance is determined based on the degree of aging of the internal resistance and the first DC internal resistance.

4. The method according to claim 3, characterized in that, When the energy interaction includes discharging, the target operating condition includes the battery being left to stand for a first preset time, and then continuously discharging at a constant rate for a second preset time. When the energy interaction includes recharging, the target operating condition includes the battery being left to rest for a third preset time, and then being continuously recharged at a constant rate for a fourth preset time.

5. The method according to any one of claims 1 to 4, characterized in that, The first preset voltage is the sum of the discharge cutoff voltage and the first voltage, and the second preset voltage is the sum of the discharge cutoff voltage and the second voltage.

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

7. The method according to any one of claims 1 to 4, characterized in that, The third preset voltage is the difference between the full charge cutoff voltage and the third voltage, and the fourth preset voltage is the sum of the full charge cutoff voltage and the fourth voltage.

8. The method according to claim 7, characterized in that, The third voltage is less than the fourth voltage.

9. The method according to any one of claims 1 to 4, characterized in that, The step of determining the predicted voltage of the battery at the next moment when it performs energy interaction at the maximum permissible power, based on the first DC internal resistance, the permissible current, the actual current, and the actual voltage, includes: The voltage change of the battery between the current moment and the next moment is determined based on the allowable current, the actual current, and the first DC internal resistance. The predicted voltage is determined based on the voltage change and the actual voltage.

10. A battery management system, characterized in that, include: The control unit is used to acquire the battery's first DC internal resistance, the allowable current corresponding to the maximum allowable power, the actual current at the current moment, and the actual voltage at the current moment, and to determine the predicted voltage of the battery when it performs energy interaction at the maximum allowable power at the next moment based on the first DC internal resistance, the allowable current, the actual current, and the actual voltage. The control unit is further configured to determine, based on the predicted voltage and the maximum allowable power, the target allowable power of the battery when performing energy interaction at the current moment, and control the battery to perform energy interaction with other devices based on the target allowable power; Wherein, the energy interaction includes the case of discharge, the maximum allowable power is the maximum allowable discharge power, the target allowable power is the target allowable discharge power, and the control unit is specifically used to, when the predicted voltage is less than or equal to a first preset voltage, reduce the maximum allowable discharge power, and the power obtained after reducing the maximum allowable discharge power is the target allowable discharge power; when the predicted voltage is greater than or equal to a second preset voltage, determine the maximum allowable discharge power as the target allowable discharge power, wherein the first preset voltage and the second preset voltage are determined based on the discharge cutoff voltage of the battery; In the case of energy interaction including recharge, the maximum allowable power is the maximum allowable recharge power, and the target allowable power is the target allowable recharge power. The control unit is specifically configured to, when the predicted voltage is greater than or equal to a third preset voltage, reduce the maximum allowable recharge power to obtain the target allowable power, and when the predicted voltage is less than or equal to a fourth preset voltage, determine the maximum allowable recharge power as the target allowable power, wherein the third preset voltage and the fourth preset voltage are determined based on the full charge cutoff voltage of the battery.

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

12. A battery system, characterized in that, include: Battery; A battery management system for performing a battery management method according to any one of claims 1 to 9 to manage the battery.

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

14. An electrical appliance, characterized in that, include: First load; According to claim 12, the battery system is connected to the first load and is used to provide a first direct current to the first load, wherein the voltage of the first direct current is greater than a voltage threshold.

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