Battery system discharge control methods, battery systems, electrical devices, and battery management systems

Abstract

This application provides a battery system discharge control method, a battery system, an electrical device, and a battery management system, which can reduce the possibility of over-discharge during the discharge process. The battery system includes a first battery and a second battery, and the battery system includes independently set energy zones. The first battery and the second battery are set in different energy zones. The method includes: acquiring a first state parameter and a second state parameter; determining a first allowable discharge power of the first battery based on the first state parameter, and determining a second allowable discharge power of the second battery based on the second state parameter; determining a target allowable discharge power of the battery system based on the first allowable discharge power and the second allowable discharge power, and controlling the battery system to discharge at the target allowable discharge power.

Description

Technical Field

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

[0002] Electric vehicles, as a type of new energy vehicle, have received widespread attention since their introduction. Battery technology is a crucial factor in the development of electric vehicles.

[0003] Over-discharge must be avoided during battery use. Therefore, reducing the possibility of battery over-discharge is an urgent problem to be solved. Summary of the Invention

[0004] This application provides a battery system discharge control method, a battery system, an electrical device, and a battery management system, which can reduce the possibility of over-discharge of the battery during the discharge process.

[0005] In a first aspect, a method for discharging a battery system is provided. The battery system includes a first battery and a second battery, and the battery system includes independently configured energy zones. The first battery and the second battery are respectively configured in different energy zones. The method includes: acquiring a first state parameter of the first battery and a second state parameter of the second battery; determining a first allowable discharge power of the first battery based on the first state parameter, and determining a second allowable discharge power of the second battery based on the second state parameter; determining a target allowable discharge power of the battery system based on the first allowable discharge power and the second allowable discharge power, and controlling the battery system to discharge using the target allowable discharge power.

[0006] In this embodiment of the application, when the battery system includes two batteries, the allowable discharge power of each battery is first determined based on the state parameters of the two batteries, and then the target allowable discharge power of the entire battery system is determined based on the allowable discharge power of the two batteries. This results in a high accuracy of the target allowable discharge power, and the battery system is then controlled to discharge based on the target discharge power, which greatly reduces the possibility of over-discharge of the two batteries.

[0007] Furthermore, the first and second batteries are located in different energy zones, which is a redundant design for the batteries. In this way, if one battery malfunctions during the use of the electrical device, the other battery can continue to supply power to the electrical device, allowing the electrical device to continue to work normally.

[0008] In some possible implementations, determining the first allowable discharge power of the first battery based on the first state parameters includes: determining a first initial allowable discharge power of the first battery based on the first state parameters; obtaining a first minimum single-cell voltage of the first battery; and adjusting the first initial allowable discharge power based on the first minimum single-cell voltage to obtain the first allowable discharge power. Determining the second allowable discharge power of the second battery based on the second state parameters includes: determining a second initial allowable discharge power of the second battery based on the second state parameters; obtaining a second minimum single-cell voltage of the second battery; and adjusting the second initial allowable discharge power based on the second minimum single-cell voltage to obtain the second allowable discharge power.

[0009] Since the state parameters of a battery are constantly changing during discharge, the initial allowable discharge power is adjusted based on the minimum single-cell voltage during discharge so that the final allowable discharge power can match the current state parameters of the battery, which can further reduce the possibility of over-discharge.

[0010] In some possible implementations, adjusting the first initial allowable discharge power based on the first minimum cell voltage to obtain the first allowable discharge power includes: adjusting the first initial allowable discharge power based on the first minimum cell voltage and the first discharge cutoff voltage of the first battery to obtain the first allowable discharge power; adjusting the second initial allowable discharge power based on the second minimum cell voltage to obtain the second allowable discharge power includes: adjusting the second initial allowable discharge power based on the second minimum cell voltage and the second discharge cutoff voltage of the second battery to obtain the second allowable discharge power.

[0011] This technical solution adjusts the allowable discharge power based not only on the minimum single-cell voltage but also on the discharge cutoff voltage of the two batteries. In other words, it adjusts the allowable discharge power based on more parameters, resulting in a higher accuracy of the final allowable discharge power and further reducing the possibility of over-discharge of the two batteries.

[0012] In some possible implementations, adjusting the first initial allowable discharge power based on the first minimum single-cell voltage and the first discharge cutoff voltage of the first battery to obtain the first allowable discharge power includes: reducing the first initial allowable discharge power to the first allowable discharge power when the first minimum single-cell voltage is less than a first preset voltage, wherein the first preset voltage is the sum of the first discharge cutoff voltage and a first voltage; determining the first initial allowable discharge power as the first allowable discharge power when the first minimum single-cell voltage is greater than or equal to a second preset voltage, wherein the second preset voltage is the sum of the first discharge cutoff voltage and a second voltage; adjusting the second initial allowable discharge power based on the second minimum single-cell voltage and the second discharge cutoff voltage of the second battery to obtain the second allowable discharge power includes: reducing the second initial allowable discharge power to the second allowable discharge power when the second minimum single-cell voltage is less than a third preset voltage, wherein the third preset voltage is the sum of the second discharge cutoff voltage and a third voltage of the second battery; determining the second initial allowable discharge power as the second allowable discharge power when the second minimum single-cell voltage is greater than or equal to a fourth preset voltage, wherein the fourth preset voltage is the sum of the second discharge cutoff voltage and a fourth voltage.

[0013] This technical solution intervenes with power limiting before the minimum single-cell voltage reaches the discharge cutoff voltage, i.e., before the minimum single-cell voltage reaches the discharge cutoff voltage. This reduces the initial allowable discharge power, thereby lowering the probability of over-discharge and subsequent undervoltage. Furthermore, the initial allowable discharge power is only determined as the final allowable discharge power when the minimum single-cell voltage exceeds both the discharge cutoff voltage and the preset voltage. This reduces the impact of the battery's "phantom charge" phenomenon, further lowering the possibility of over-discharge.

[0014] In some possible implementations, reducing the first initial allowable discharge power to the first allowable discharge power when the first minimum cell voltage is less than a first preset voltage includes: determining a first target adjustment value for the first initial allowable discharge power based on the first minimum cell voltage and a plurality of first correspondences between the first cell voltage and a first adjustment value; and reducing the first initial allowable discharge power to the first allowable discharge power based on the first target adjustment value. Reducing the second initial allowable discharge power to the second allowable discharge power when the second minimum cell voltage is less than a third preset voltage includes: determining a second target adjustment value for the second allowable discharge power based on the second minimum cell voltage and a plurality of second correspondences between the second cell voltage and a second adjustment value; and reducing the second initial allowable discharge power to the second allowable discharge power based on the second target adjustment value.

[0015] In this technical solution, there are multiple correspondences between the first cell voltage and the first adjustment value, and there are also multiple correspondences between the second cell voltage and the second adjustment value. This 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.

[0016] In some possible implementations, the first voltage is less than the second voltage, and / or the third voltage is less than the fourth voltage.

[0017] Setting the second voltage to be greater than the first voltage, and / or setting the third voltage to be less than the fourth 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, and / or between the third and fourth voltages, can reduce the probability of repeatedly triggering the strategy of adjusting the allowable power, thereby improving discharge efficiency.

[0018] In some possible implementations, determining the first allowable discharge power of the first battery based on the first state parameter and determining the second allowable discharge power of the second battery based on the second state parameter includes: determining the first maximum discharge power of the first battery based on the first state parameter and determining the second maximum discharge power of the second battery based on the second state parameter; determining the first allowable discharge power based on the first maximum discharge power and determining the second allowable discharge power based on the second maximum discharge power.

[0019] This technical solution first determines the maximum discharge power of the two batteries based on the state parameters, and then determines the initial allowable discharge power of the two batteries based on the maximum discharge power. Since there is a certain relationship between the maximum discharge power and the allowable discharge power, the initial allowable discharge power determined based on the maximum discharge power is relatively accurate, thereby further reducing the probability of over-discharge problems in the two batteries.

[0020] In some possible implementations, determining the first allowable discharge power based on the first maximum discharge power includes: determining the first allowable discharge power based on the first maximum discharge power and at least one of the following: the fault condition of the battery system, the fault condition of the first battery, the voltage of the first battery, and the actual power used by the first battery; determining the second allowable discharge power based on the second maximum discharge power includes: determining the second allowable discharge power based on the second maximum discharge power and at least one of the following: the fault condition of the battery system, the fault condition of the second battery, the voltage of the second battery, and the actual power used by the second battery.

[0021] The above technical solution determines the allowable discharge power of the first battery and the second battery based on the above parameters. Since the allowable discharge power is closely related to the above parameters, the accuracy of the determined allowable discharge power is relatively high.

[0022] In some possible implementations, when the first allowable discharge power is less than the second allowable discharge power, the target allowable discharge power is twice the first allowable discharge power; when the second allowable discharge power is less than the first allowable discharge power, the target allowable discharge power is twice the second allowable discharge power.

[0023] If the first and second batteries are connected in series in the same circuit, they will discharge with the same current. If the allowable discharge current of one battery is less than the discharge current of the other battery, over-discharge may occur. Therefore, this technical solution sets the target allowable discharge power to twice the minimum of the two allowable discharge powers. In this way, the allowable discharge current of both batteries is not less than their discharge current, thereby reducing the possibility of over-discharge.

[0024] In a second aspect, a battery system is provided, the battery system including a first battery and a second battery, the battery system including independently configured energy zones, the first battery and the second battery being respectively disposed in different energy zones, the battery system including: a sampling unit, configured to acquire a first state parameter of the first battery and a second state parameter of the second battery; a control unit, configured to determine a first allowable discharge power of the first battery based on the first state parameter, and determine a second allowable discharge power of the second battery based on the second state parameter, and determine a target allowable discharge power of the battery system based on the first allowable discharge power and the second allowable discharge power, and control the battery system to discharge with the target allowable discharge power.

[0025] Thirdly, an electrical device is provided, comprising: a first load; a second load; and a battery system as described in the second aspect above, wherein the battery system is connected to the first load and is used to provide a first direct current to the first load, and / or, the battery system is connected to the second load and is used to provide 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.

[0026] Fourthly, 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 invoke the computer program to execute the methods in the first aspect or its various implementations described above.

[0027] Fifthly, 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 various implementations.

[0028] Sixthly, 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

[0029] Figure 1 A schematic diagram of a battery comprising two energy zones is shown, according to an embodiment of this application.

[0030] Figure 2 A schematic flowchart of a battery system discharge control method according to an embodiment of this application is shown.

[0031] Figure 3 A schematic diagram illustrating the connection of a first battery and a second battery according to an embodiment of this application is shown.

[0032] Figure 4 A schematic flowchart of another battery system discharge control method according to an embodiment of this application is shown.

[0033] Figure 5 A flowchart illustrating a specific battery system discharge control method according to an embodiment of this application is shown.

[0034] Figure 6 A schematic block diagram of a battery system according to an embodiment of this application is shown.

[0035] Figure 7 A schematic block diagram of a battery management system according to an embodiment of this application is shown.

[0036] Figure 8 A schematic diagram of an electrical device according to an embodiment of this application is shown. Detailed Implementation

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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).

[0042] In the field of new energy, batteries, as the primary power source for electrical devices such as vehicles, ships, or spacecraft, are undeniably crucial. To further improve battery performance and safety, multiple independently operating energy zones can be configured, for example... Figure 1 As shown, two independent energy zones can be set up, thereby enabling multiple redundancy designs and energy management, such as high-voltage flexible power supply, low-voltage flexible power supply, thermal management redundancy, and thermal runaway isolation.

[0043] Setting up independent energy zones ensures stable power output and reduces the likelihood of electrical devices being affected by power failures. This allows another zone to maintain power supply even in the event of a single zone failure, ensuring the continued normal operation of the devices. Furthermore, independent energy zones allow for more flexible battery system design, catering to diverse usage scenarios. For example, independent energy zones can be paired with battery cells exhibiting different temperature performance characteristics and each zone can have its own independent temperature control. This allows the battery system to adapt to both extremely cold and high-temperature environments, enabling it to perform at its best under a wider range of conditions.

[0044] At this point, the battery system with multiple energy zones (multiple battery packs) needs to avoid over-discharge during the discharge process, as over-discharge can cause a variety of problems.

[0045] Firstly, it will cause microscopic chemical damage, such as (1) the negative electrode current collector dissolving, and the dissolved copper ions will be randomly deposited between the positive and negative electrodes during subsequent charging, forming copper dendrites; (2) the positive electrode material structure collapses, causing the positive electrode to be unable to effectively insert or extract lithium ions, and the battery capacity will be permanently lost; (3) the decomposition and regeneration of the solid electrolyte interface (SEI) film, so that the SEI film will be reformed when recharged. This process will continuously consume electrolyte and effective lithium ions, resulting in an increase in battery internal resistance and a further decrease in capacity.

[0046] Secondly, it will cause the battery performance to degrade, such as (1) a sudden decrease in capacity; (2) an increase in internal resistance, which will lead to more severe heat generation of the battery during charging and discharging, lower energy efficiency, weak acceleration of electrical devices, and slower fast charging speed; (3) an increase in self-discharge rate.

[0047] Thirdly, it can cause system-level failures and affect user experience, such as (1) the battery completely fails. The battery management system (BMS) will detect the abnormal voltage of the over-discharged battery cell. In order to prevent danger, the BMS will lock the battery, making it unusable; (2) the electrical device cannot be used; (3) high maintenance costs.

[0048] In view of this, this application provides a battery system discharge control method. The battery system includes a first battery and a second battery, and the battery system includes independently set energy zones. The first battery and the second battery are respectively set in different energy zones. The method includes: acquiring a first state parameter of the first battery and a second state parameter of the second battery; determining a first allowable discharge power of the first battery based on the first state parameter; determining a second allowable discharge power of the second battery based on the second state parameter; then determining a target allowable discharge power of the battery system based on the first allowable discharge power and the second allowable discharge power; and controlling the battery system discharge based on the target allowable discharge power. This scheme, when the battery system includes two batteries, first determines the allowable discharge power of each battery based on its state parameters, and then determines the target allowable discharge power of the entire battery system based on the allowable discharge power of the two batteries. This results in a high accuracy of the obtained target allowable discharge power, and the battery system is then controlled to discharge based on the target discharge power, which greatly reduces the possibility of over-discharge of the two batteries.

[0049] Furthermore, the first and second batteries are located in different energy zones, which is a redundant design for the batteries. In this way, if one battery malfunctions during the use of the electrical device, the other battery can continue to supply power to the electrical device, allowing the electrical device to continue to work normally.

[0050] 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.

[0051] 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.

[0052] 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, a lithium-ion battery can be a ternary lithium battery, a lithium iron phosphate battery, etc. Regarding the size of the battery, the battery in this application embodiment can be a battery module or a battery pack, etc. In this application embodiment, the specific type and size of the battery are not specifically limited.

[0053] Figure 2 A schematic flowchart of a battery system discharge control method 200 according to an embodiment of this application is shown. The battery system includes a first battery and a second battery, and the battery system includes independently configured energy zones, with the first battery and the second battery respectively disposed in different energy zones.

[0054] Method 200 may include at least some of the following.

[0055] S210: Obtain the first state parameters of the first battery and the second state parameters of the second battery.

[0056] S220: Determine the first allowable discharge power of the first battery based on the first state parameters, and determine the second allowable discharge power of the second battery based on the second state parameters.

[0057] S230: Determine the target allowable discharge power of the battery system based on the first allowable discharge power and the second allowable discharge power, and control the battery system to discharge using the target allowable discharge power.

[0058] In this embodiment of the application, when the battery system includes two batteries, the allowable discharge power of each battery is first determined based on the state parameters of the two batteries, and then the target allowable discharge power of the entire battery system is determined based on the allowable discharge power of the two batteries. This results in a high accuracy of the target allowable discharge power, and the battery system is then controlled to discharge based on the target discharge power, which greatly reduces the possibility of over-discharge of the two batteries.

[0059] Furthermore, the first and second batteries are located in different energy zones, which is a redundant design for the batteries. In this way, if one battery malfunctions during the use of the electrical device, the other battery can continue to supply power to the electrical device, allowing the electrical device to continue to work normally.

[0060] A battery system can specifically consist of a battery and a battery management system. The battery system includes a first battery and a second battery, which can specifically be a battery pack, a battery module, or a collection of batteries formed by the electrical connection of individual battery cells.

[0061] An energy zone is a portion of a battery system that can operate and be controlled independently. For example, each energy zone can be charged and discharged independently. The energy zones can be divided according to the battery configuration within the system. Optionally, when the battery system includes one or more battery packs, energy zones can be divided within each battery pack. The first and second batteries can be located in different energy zones within each battery pack, and separator beams can be used to isolate the energy zones. Alternatively, when the battery system includes multiple battery packs, each battery pack can be considered a separate energy zone, forming multiple energy zones across the battery packs.

[0062] It should be understood that the first battery in the embodiments of this application may also be referred to as the first battery pack, and the second battery may also be referred to as the second battery pack.

[0063] The first and second batteries can be connected in series. Alternatively, the first and second batteries can be connected via a voltage converter. Or, the first and second batteries can be connected in parallel.

[0064] The number of voltage converters can be one or more.

[0065] A voltage converter can be a device or circuit used to achieve power input-output conversion, such as a direct current / direct current (DC / DC) converter or a flyback converter. Optionally, a DC / DC converter can be a unidirectional DC / DC converter, or it can be a bidirectional DC / DC converter.

[0066] Figure 3 A schematic diagram illustrating the connection of a first battery and a second battery according to an embodiment of this application is shown. By controlling the series switch module, switching between series connection and parallel connection between the first battery and the second battery can be achieved.

[0067] 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.

[0068] In some embodiments, the type of the first battery may be different from that of the second battery, as long as the output of the first battery and the second battery meet the system requirements.

[0069] 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.

[0070] This technical solution sets the first battery and the second battery as different types of batteries, enabling the battery system to meet different usage scenarios and thus allowing the battery system to perform under more operating conditions.

[0071] Among them, power batteries can provide power output to meet the demand for large amounts of energy in a short period of time, and can be used in the electric drive system of electrical devices, such as for acceleration and hill climbing. Energy batteries can store as much energy as possible and are suitable for electrical devices that require longer driving range.

[0072] The first state parameter includes at least one of the temperature, voltage, and current of the first battery; the second state parameter includes at least one of the temperature, current, and voltage of the second battery; the battery system consists of the first battery and the second battery; and the target allowable discharge power is used to discharge the first battery and the second battery.

[0073] Alternatively, the types of the first and second batteries can be set to be the same.

[0074] In some embodiments, both the first battery and the second battery can be energy-type batteries, or both can be power-type batteries. This technical solution sets both the first battery and the second battery as either energy-type or power-type batteries. This ensures that the first battery and the second battery are of the same type and have the same discharge rate, thereby reducing the possibility of over-discharge due to inconsistent discharge rates between the two batteries during the discharge process.

[0075] The first state parameter includes at least one of the following: temperature, voltage, current, state of charge (SOC), and state of health (SOH) of the first battery. The second state parameter may include at least one of the following: temperature, current, voltage, SOC, and SOH of the second battery.

[0076] Optionally, the first state parameter can be obtained through the BMS of the first battery. For example, the first state parameter can be monitored in real time, or it can be obtained at preset time intervals, such as 10 milliseconds (ms), 50 ms, 100 ms, 1 second (s), etc.

[0077] Similarly, the second state parameter can be obtained through the BMS of the second battery. For example, the second state parameter can be monitored in real time, or it can be obtained at preset time intervals, such as 10ms, 50ms, 100ms, 1s, etc.

[0078] In some embodiments, S220 may specifically include: determining a first maximum discharge power of the first battery based on a first state parameter, determining a second maximum discharge power of the second battery based on a second state parameter, determining a first allowable discharge power based on the first maximum discharge power, and determining a second allowable discharge power based on the second maximum discharge power.

[0079] Among them, the maximum discharge power can be understood as the static discharge capacity of the battery, and the allowable discharge power can be understood as the dynamic discharge capacity of the battery. The allowable discharge capacity is usually less than or equal to the maximum discharge capacity.

[0080] Optionally, if the first state parameter does not include the SOC of the first battery, the SOC of the first battery can be calculated based on the first state parameter, and then the first maximum discharge power can be determined based on the SOC, temperature and discharge power table of the first battery.

[0081] Similarly, if the second state parameter does not include the SOC of the second battery, the SOC of the second battery can be calculated based on the second state parameter, and then the second maximum discharge power can be determined based on the SOC, temperature, and discharge power table of the second battery.

[0082] After determining the first maximum discharge power and the second maximum discharge power, the first allowable discharge power can be determined based on the first maximum discharge power, and based on at least one of the following: the fault condition of the battery system, the fault condition of the first battery, the voltage of the first battery, and the actual power used by the first battery.

[0083] The voltage of the first battery may include at least one of the following: the terminal voltage of the first battery, the voltage of each cell in the first battery, and the voltage of the cell with the worst discharge energy in the first battery.

[0084] When the battery system or the first battery malfunctions, the first permissible discharge power can be lower than the first permissible discharge power when it is not malfunctioning. In other words, if the battery system or the first battery malfunctions, the first permissible discharge power needs to be limited. For example, if the first battery's SOC is 50% and its temperature is 25°C, the first permissible discharge power is 100 kilowatts (kW). If the temperature of the first battery rises to 80°C, it indicates that the first battery has overheated, which can be considered a malfunction. Therefore, the first permissible discharge power needs to be limited, for example, to 70 kW.

[0085] Fault conditions may include, but are not limited to, overvoltage, undervoltage, overcurrent, overtemperature, low temperature, and battery deformation.

[0086] Similarly, the second allowable discharge power can be determined based on the second maximum discharge power, and based on at least one of the following: the fault condition of the battery system, the fault condition of the second battery, the voltage of the second battery, and the actual power used by the second battery.

[0087] This technical solution determines the allowable discharge power of the first battery and the second battery based on the above parameters. Since the allowable discharge power is closely related to the above parameters, the accuracy of the determined allowable discharge power is relatively high.

[0088] Considering that the state parameters of the battery are constantly changing during discharge, in order to make the final determined allowable discharge power more accurate, in some embodiments, such as Figure 4 As shown, S220 may specifically include: S221a: determining the first initial allowable discharge power of the first battery according to the first state parameters; S222a: obtaining the first minimum single cell voltage of the first battery; S223a: adjusting the first initial allowable discharge power according to the first minimum single cell voltage to obtain the first allowable discharge power.

[0089] S220 may further include: S221b: determining the second initial allowable discharge power of the second battery based on the second state parameters; S222b: obtaining the second minimum single-cell voltage of the second battery; S223b: adjusting the second initial allowable discharge power based on the second minimum single-cell voltage to obtain the second allowable discharge power.

[0090] Since the state parameters of a battery are constantly changing during discharge, the initial allowable discharge power is adjusted based on the minimum single-cell voltage during discharge so that the final allowable discharge power can match the current state parameters of the battery, which can further reduce the possibility of over-discharge.

[0091] The first minimum single-cell voltage is the lowest voltage among the multiple single cells of the first battery, and the second minimum single-cell voltage is the lowest voltage among the multiple single cells of the second battery.

[0092] In some embodiments, determining the first initial allowable discharge power based on the first state parameters may specifically include: determining the first maximum discharge power of the first battery based on the first state parameters, and then determining the first allowable discharge power based on the first maximum discharge power.

[0093] The second initial allowable discharge power is determined based on the second state parameters. Specifically, this may include: determining the second maximum discharge power of the second battery based on the second state parameters, and then determining the second allowable discharge power based on the second maximum discharge power.

[0094] This technical solution first determines the maximum discharge power of the two batteries based on the state parameters, and then determines the initial allowable discharge power of the two batteries based on the maximum discharge power. Since there is a certain relationship between the maximum discharge power and the allowable discharge power, the initial allowable discharge power determined based on the maximum discharge power is relatively accurate, thereby further reducing the probability of over-discharge problems in the two batteries.

[0095] For a detailed explanation of how to determine the first initial allowable discharge power based on the first maximum discharge power, please refer to the explanation of how to determine the first allowable discharge power based on the first maximum discharge power. For a detailed explanation of how to determine the second initial allowable discharge power based on the second maximum discharge power, please refer to the explanation of how to determine the second allowable discharge power based on the second maximum discharge power. These details will not be repeated here.

[0096] In some embodiments, a first minimum cell voltage can be compared with a threshold, and the first initial allowable discharge power can be adjusted based on the comparison result. Similarly, a second minimum cell voltage can be compared with a threshold, and the second initial allowable discharge power can be adjusted based on the comparison result.

[0097] In other embodiments, adjusting the first initial allowable discharge power to a first allowable discharge power based on a first minimum cell voltage can specifically include: adjusting the first initial allowable discharge power to a first allowable discharge power based on the first minimum cell voltage and the first discharge cutoff voltage of the first battery. Adjusting the second initial allowable discharge power to a second allowable discharge power based on a second minimum cell voltage can specifically include: adjusting the second initial allowable discharge power to a second allowable discharge power based on the second minimum cell voltage and the second discharge cutoff voltage of the second battery.

[0098] This technical solution adjusts the allowable discharge power based not only on the minimum single-cell voltage but also on the discharge cutoff voltage of the two batteries. In other words, it adjusts the allowable discharge power based on more parameters, resulting in a higher accuracy of the final allowable discharge power and further reducing the possibility of over-discharge of the two batteries.

[0099] 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.

[0100] As an example, the first minimum cell voltage and the first discharge cutoff voltage can be directly compared. If the first minimum cell voltage is less than the first discharge cutoff voltage, the first initial allowable discharge power is reduced to the first allowable discharge power. If the first minimum cell voltage is greater than or equal to the first discharge cutoff voltage, the first initial allowable discharge power is kept unchanged, that is, the first initial allowable discharge power is determined as the first allowable discharge power.

[0101] For example, if the first initial allowable discharge power of the first battery is 100 kW, the first discharge cutoff voltage is 2.6 volts (V), and the first minimum single-cell voltage is 2 V at the first moment, then the first initial allowable discharge power can be reduced, for example, to 70 kW. Therefore, the first allowable discharge power at the first moment is 70 kW. Afterward, the discharge stops, and the first minimum single-cell voltage rises to 3 V. At this point, the first minimum single-cell voltage is greater than the first discharge cutoff voltage, so the first allowable discharge power at the second moment can be restored to the first initial allowable discharge power of 100 kW.

[0102] Similarly, the second minimum cell voltage and the second discharge cutoff voltage can be directly compared. If the second minimum cell voltage is less than the second discharge cutoff voltage, the second initial allowable discharge power is reduced to the second allowable discharge power. If the second minimum cell voltage is greater than or equal to the second discharge cutoff voltage, the second initial allowable discharge power is kept unchanged, that is, the second initial allowable discharge power is determined as the second allowable discharge power.

[0103] 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 minimum single-cell voltage reaches the discharge cutoff voltage to reduce the possibility of undervoltage.

[0104] Furthermore, after a battery stops discharging, it may experience a voltage rebound, meaning the battery's terminal voltage may gradually rise to a relatively stable, higher value. 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," meaning the battery may not actually function at 2.5V. To mitigate the impact of this phantom voltage, the allowable discharge power can be restored to the initial allowable discharge power only when the minimum single-cell voltage exceeds the discharge cutoff voltage by a certain margin.

[0105] Therefore, as another example, adjusting the first initial allowable discharge power to the first allowable discharge power based on the first minimum cell voltage and the first discharge cutoff voltage can specifically include: reducing the first initial allowable discharge power to the first allowable discharge power when the first minimum cell voltage is less than the first preset voltage; and determining the first initial allowable discharge power as the first allowable discharge power when the first minimum cell voltage is greater than or equal to the second preset voltage.

[0106] Wherein, the first preset voltage is the sum of the first discharge cutoff voltage and the first voltage, and the second preset voltage is the sum of the first discharge cutoff voltage and the second voltage.

[0107] The second allowable discharge power is adjusted to the second allowable discharge power based on the second minimum cell voltage and the second discharge cutoff voltage. Specifically, this may include: reducing the second initial allowable discharge power to the second allowable discharge power when the second minimum cell voltage is less than the third preset voltage; and determining the second initial allowable discharge power as the second allowable discharge power when the second minimum cell voltage is greater than or equal to the fourth preset voltage.

[0108] The third preset voltage is the sum of the second discharge cutoff voltage and the third voltage, and the fourth preset voltage is the sum of the second discharge cutoff voltage and the fourth voltage.

[0109] This technical solution intervenes with power limiting before the minimum single-cell voltage reaches the discharge cutoff voltage, i.e., before the minimum single-cell voltage reaches the discharge cutoff voltage. This reduces the initial allowable discharge power, thereby lowering the probability of over-discharge and subsequent undervoltage. Furthermore, the initial allowable discharge power is only determined as the final allowable discharge power when the minimum single-cell voltage exceeds both the discharge cutoff voltage and the preset voltage. This reduces the impact of the battery's "phantom charge" phenomenon, further lowering the possibility of over-discharge.

[0110] Optionally, the first and second voltages can be determined based on at least one of the following: empirical parameters, the direct current resistance (DCR) of the first battery, and the discharge characteristic map (i.e., discharge map) of the first battery. Similarly, the third and fourth voltages can be determined based on at least one of the following: empirical parameters, the DCR of the second battery, and the discharge map of the second battery.

[0111] 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.

[0112] Alternatively, the first voltage can be different from the second voltage. For example, the first voltage can be greater than the second voltage, or the first voltage can be less than the second voltage; for instance, the first voltage is 300mV and the second voltage is 350mV. Setting the second voltage to be greater than the first 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 allowable power adjustment strategy, thereby improving discharge efficiency.

[0113] Similarly, the third voltage can be the same as or different from the fourth voltage. For example, the third voltage can be lower than the fourth voltage. Setting the third voltage to be lower than the fourth voltage can further reduce the impact of the battery's virtual charge phenomenon, thereby effectively reducing the possibility of over-discharge. In addition, the presence of an interval between the third and fourth voltages, such as a 50 millivolt (mV) interval, can reduce the probability of repeatedly triggering the strategy of adjusting the allowable power, thereby improving discharge efficiency.

[0114] Optionally, the first voltage can be the same as the third voltage, for example, both being 300mV, and the second voltage can be the same as the fourth voltage, for example, both being 350mV. Of course, the first voltage can also be different from the third voltage, and the second voltage can also be different from the fourth voltage.

[0115] Optionally, when the first minimum single-cell voltage is less than the first preset voltage, the specific amount by which the first initial allowable discharge power is reduced can be determined based on experience, or based on the attribute parameters of the first battery, or based on the application scenario of the first battery.

[0116] Similarly, when the second minimum single-cell voltage is less than the second preset voltage, the specific amount by which the second initial allowable discharge power is reduced can be determined based on experience, or based on the attribute parameters of the second battery, or based on the application scenario of the second battery.

[0117] In some embodiments, as long as the first minimum cell voltage is less than the first preset voltage, the adjustment value of the first initial allowable discharge power can be the same, that is, the final obtained first allowable discharge power is the same. Similarly, as long as the second minimum cell voltage is less than the second preset voltage, the adjustment value of the second initial allowable discharge power can also be the same, that is, the final obtained second allowable discharge power is the same.

[0118] For example, if the first initial allowable discharge power is 100KW, the first preset voltage is 3.3V, and the first minimum single-cell voltage is 3V, reducing the first initial allowable discharge power by 20% will result in a first allowable discharge power of 80KW. Similarly, if the first minimum single-cell voltage is 2.8V, reducing the first initial allowable discharge power by 20% will also result in a first allowable discharge power of 80KW.

[0119] In other embodiments, the first minimum cell voltage can be divided into multiple levels, with different adjustment values ​​corresponding to different levels. In other words, a first target adjustment value for the first initial allowable discharge power can be determined based on the first minimum cell voltage and multiple first correspondences between the first cell voltage and the first adjustment value. Then, based on the first target adjustment value, the first initial allowable discharge power is reduced to the first allowable discharge power. Similarly, a second target adjustment value for the second initial allowable discharge power can be determined based on the second minimum cell voltage and multiple second correspondences between the second cell voltage and the second adjustment value. Then, based on the second target adjustment value, the second initial allowable discharge power is reduced to the second allowable discharge power.

[0120] In this technical solution, there are multiple correspondences between the first cell voltage and the first adjustment value, and there are also multiple correspondences between the second cell voltage and the second adjustment value. This 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.

[0121] Optionally, the multiple first correspondences can be determined based on the attribute parameters of the first battery, and the multiple second correspondences can be determined based on the attribute parameters of the second battery.

[0122] For example, assuming the first preset voltage is 3.3V, several first correspondences include: when the first cell voltage is less than 3.3V but greater than or equal to 3V, the first adjustment value is 40%; when the first cell voltage is less than 3V but greater than or equal to 2.8V, the first adjustment value is 60%; and when the first cell voltage is less than 2.8V, the first adjustment value is 80%. Here, the adjustment value a% represents a reduction of a in the initial allowable discharge power.

[0123] If the first initial allowable discharge power is 100KW and the first minimum single-cell voltage is 3.1V, and the first target adjustment value is 40%, then the first allowable discharge power is 60KW; if the first minimum single-cell voltage is 2.6V, then the first target adjustment value is 80%, and the first allowable discharge power is 20KW.

[0124] After determining the first allowable discharge power and the second allowable discharge power, the target allowable discharge power of the battery system can be determined based on the first allowable discharge power and the second allowable discharge power.

[0125] Optionally, if the first allowable discharge power is less than the second allowable discharge power, the target allowable discharge power can be twice the first allowable discharge power. If the second allowable discharge power is less than the first allowable discharge power, the target allowable discharge power can be twice the second allowable discharge power.

[0126] In other words, the target allowable discharge power P satisfies the following formula:

[0127] P = min(first allowable discharge power, second allowable discharge power) * 2 (1)

[0128] If the first and second batteries are connected in series in the same circuit, they will discharge with the same current. If the allowable discharge current of one battery is less than the discharge current of the other battery, over-discharge may occur. Therefore, this technical solution sets the target allowable discharge power to twice the minimum of the two allowable discharge powers. In this way, the allowable discharge current of both batteries is not less than their discharge current, thereby reducing the possibility of over-discharge.

[0129] Then, the battery system can be controlled to discharge at the target allowable discharge power.

[0130] The following is combined Figure 5 A specific embodiment of this application is described. Figure 5 In the above, the first and third voltages are both 300mV, and the second and fourth voltages are both 350mV.

[0131] In 501a, the current and temperature of the first battery are obtained.

[0132] In 502a, the SOC of the first battery is calculated based on the current and temperature of the first battery.

[0133] In 503a, the first maximum discharge power of the first battery is obtained by looking up the power table using the SOC and temperature of the first battery.

[0134] In 504a, the first initial allowable discharge power of the first battery is obtained based on the first maximum discharge power.

[0135] In the 505a, the first minimum single cell voltage of the first battery is monitored in real time.

[0136] If the first minimum cell voltage is less than (first discharge cutoff voltage + 300mV), then proceed to step 506a. If the first minimum cell voltage is greater than or equal to (first discharge cutoff voltage + 350mV), then proceed to step 507a.

[0137] In 506a, the first initial allowable discharge power is reduced to obtain the first allowable discharge power.

[0138] In 507a, the first initial allowable discharge power is defined as the first allowable discharge power.

[0139] In 501b, the current and temperature of the second battery are obtained.

[0140] In 502b, the SOC of the second battery is calculated based on the current and temperature of the second battery.

[0141] In 503b, the second maximum discharge power of the second battery is obtained by looking up the power table using the state of charge (SOC) and temperature of the second battery.

[0142] In 504b, the second initial allowable discharge power of the second battery is obtained based on the second maximum discharge power.

[0143] In the 505b, the second minimum single cell voltage of the second battery is monitored in real time.

[0144] If the second minimum cell voltage is less than (second discharge cutoff voltage + 300mV), then proceed to step 506b. If the second minimum cell voltage is greater than or equal to (second discharge cutoff voltage + 350mV), then proceed to step 507b.

[0145] In 506b, the second initial allowable discharge power is reduced to obtain the second allowable discharge power.

[0146] In 507b, the second initial allowable discharge power is defined as the second allowable discharge power.

[0147] In 508, the target allowable discharge power is determined based on the first allowable discharge power and the second allowable discharge power.

[0148] For example, the target discharge power can be calculated according to formula (1).

[0149] Steps 501a-507a and 501b-507b can be executed simultaneously. For example, steps 501a and 501b can be executed simultaneously, as can steps 502a and 502b.

[0150] 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.

[0151] 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.

[0152] The battery system discharge control method of the present application embodiments has been described in detail above. The battery system of the present application embodiments will be described below. It should be understood that the battery system in the present application embodiments can execute the battery system discharge control method of the present application embodiments.

[0153] Figure 6 A schematic block diagram of a battery system 600 according to an embodiment of this application is shown. The battery system 600 includes a first battery and a second battery, and the battery system includes independently configured energy zones, with the first battery and the second battery respectively disposed in different energy zones. Figure 6 As shown, the battery system 600 includes:

[0154] The sampling unit 610 is used to acquire the first state parameters of the first battery and the second state parameters of the second battery.

[0155] The control unit 620 is configured to determine a first allowable discharge power of the first battery based on the first state parameter, and a second allowable discharge power of the second battery based on the second state parameter, and to determine a target allowable discharge power of the battery system based on the first allowable discharge power and the second allowable discharge power, and to control the battery system 600 to discharge at the target allowable discharge power.

[0156] Optionally, in this embodiment of the application, the sampling unit 610 is further configured to: obtain the first minimum single-cell voltage of the first battery; the control unit 620 is specifically configured to: determine the first initial allowable discharge power of the first battery according to the first state parameters, and adjust the first initial allowable discharge power according to the first minimum single-cell voltage to obtain the first allowable discharge power.

[0157] The sampling unit 610 is further configured to: acquire the second minimum single-cell voltage of the second battery; the control unit 620 is specifically configured to: determine the second initial allowable discharge power of the second battery according to the second state parameter, and adjust the second initial allowable discharge power according to the second minimum single-cell voltage to obtain the second allowable discharge power.

[0158] Optionally, in this embodiment of the application, the control unit 620 is specifically configured to: adjust the first initial allowable discharge power according to the first minimum single cell voltage and the first discharge cutoff voltage of the first battery to obtain a first allowable discharge power; and adjust the second initial allowable discharge power according to the second minimum single cell voltage and the second discharge cutoff voltage of the second battery to obtain a second allowable discharge power.

[0159] Optionally, in this embodiment of the application, the control unit 620 is specifically configured to: reduce the first initial allowable discharge power to the first allowable discharge power when the first minimum single-cell voltage is less than the first preset voltage, wherein the first preset voltage is the sum of the first discharge cutoff voltage and the first voltage; and determine the first initial allowable discharge power to the first allowable discharge power when the first minimum single-cell voltage is greater than or equal to the second preset voltage, wherein the second preset voltage is the sum of the first discharge cutoff voltage and the second voltage.

[0160] The control unit 620 is specifically configured to: reduce the second initial allowable discharge power to the second allowable discharge power when the second minimum single cell voltage is less than the third preset voltage, wherein the third preset voltage is the sum of the second discharge cutoff voltage and the third voltage of the second battery; and determine the second initial allowable discharge power to the second allowable discharge power when the second minimum single cell voltage is greater than or equal to the fourth preset voltage, wherein the fourth preset voltage is the sum of the second discharge cutoff voltage and the fourth voltage.

[0161] Optionally, in this embodiment of the application, the control unit 620 is further configured to: determine a first target adjustment value of the first initial allowable discharge power based on the first minimum single-cell voltage and a plurality of first correspondences between the first single-cell voltage and the first adjustment value; and reduce the first initial allowable discharge power to the first allowable discharge power based on the first target adjustment value.

[0162] The control unit 620 is further configured to: determine a second target adjustment value for the second allowable discharge power based on the second minimum cell voltage and a plurality of second correspondences between the second cell voltage and the second adjustment value; and reduce the second initial allowable discharge power to the second allowable discharge power based on the second target adjustment value.

[0163] Optionally, in embodiments of this application, the first voltage is less than the second voltage, and / or the third voltage is less than the fourth voltage.

[0164] Optionally, in this embodiment of the application, the control unit 620 is specifically configured to: determine the first maximum discharge power of the first battery based on the first state parameter, and determine the second maximum discharge power of the second battery based on the second state parameter; determine the first allowable discharge power based on the first maximum discharge power, and determine the second allowable discharge power based on the second maximum discharge power.

[0165] Optionally, in this embodiment of the application, the control unit 620 is specifically configured to: determine the first allowable discharge power based on the first maximum discharge power and at least one of the fault conditions of the battery system, the fault conditions of the first battery, the voltage of the first battery, and the actual power used by the first battery; and determine the second allowable discharge power based on the second maximum discharge power and at least one of the fault conditions of the battery system, the fault conditions of the second battery, the voltage of the second battery, and the actual power used by the second battery.

[0166] Optionally, in this embodiment of the application, when the first allowable discharge power is less than the second allowable discharge power, the target allowable discharge power is twice the first allowable discharge power; when the second allowable discharge power is less than the first allowable discharge power, the target allowable discharge power is twice the second allowable discharge power.

[0167] It should be understood that the battery system 600 can perform the corresponding operations in the battery system discharge control method 200, which will not be elaborated here for the sake of brevity.

[0168] Figure 7 This is a schematic diagram of the hardware structure of a battery management system 700 according to an embodiment of this application. The battery management system 700 includes a memory 710, a processor 720, a communication interface 730, and a bus 740. The memory 710, processor 720, and communication interface 730 are interconnected via the bus 740.

[0169] The memory 710 may be a read-only memory (ROM), a static storage device, or a random access memory (RAM). The memory 710 may store a program, and when the program stored in the memory 710 is executed by the processor 720, the processor 720 and the communication interface 730 are used to execute the various steps of the battery system discharge control method of the embodiments of this application.

[0170] The processor 720 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 achieve the functions required by the units in the battery management system 700 of this application embodiment, or to execute the battery system discharge control method of this application embodiment.

[0171] The processor 720 can also be an integrated circuit chip with signal processing capabilities. In implementation, each step of the battery system discharge control method of this application embodiment can be completed by the integrated logic circuitry in the processor 720 or by software instructions.

[0172] The processor 720 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 710. The processor 720 reads the information in memory 710 and, in conjunction with its hardware, completes the functions required by the units included in the battery management system 700 of this application embodiment, or executes the battery system discharge control method of this application embodiment.

[0173] The communication interface 730 uses a transceiver device, such as, but not limited to, a transceiver, to enable communication between the battery management system 700 and other devices or communication networks.

[0174] Bus 740 may include a pathway for transmitting information between various components of the battery management system 700 (e.g., memory 710, processor 720, communication interface 730).

[0175] It should be noted that although the battery management system 700 described above only shows a memory, processor, and communication interface, those skilled in the art should understand that in specific implementations, the battery management system 700 may also include other devices necessary for normal operation. Furthermore, depending on specific needs, those skilled in the art should understand that the battery management system 700 may also include hardware devices for implementing other additional functions. In addition, those skilled in the art should understand that the battery management system 700 may only include the devices necessary for implementing the embodiments of this application, and may not necessarily include... Figure 7 All the devices shown.

[0176] like Figure 8As shown in the figure, this application embodiment also provides an electrical device 800, which includes a first load 810, a second load 820 and a battery system 830. The battery system 830 is connected to the first load 810 and is used to provide a first DC power to the first load 810, and / or the battery system 830 is connected to the second load 820 and is used to provide a second DC power to the second load 820. The voltage of the first DC power is greater than a voltage threshold, and the voltage of the second DC power is less than a voltage threshold.

[0177] In other words, the first load 810 is a high-voltage load, the second load 820 is a low-voltage load, and the battery system 830 provides low-voltage power to the first load 810 and high-voltage power to the second load 820.

[0178] Optionally, the electrical device 800 may be an electric vehicle, and the battery system 830 may be a battery system 600.

[0179] 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.

[0180] The aforementioned computer-readable storage medium may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0181] 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 system discharge control method.

[0182] 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 battery system discharge control method characterized by, The battery system comprises a first battery and a second battery, and the battery system comprises independently arranged energy zones, the first battery and the second battery are arranged in different energy zones respectively, and the method comprises: obtaining a first state parameter of the first battery, a first minimum single cell voltage of the first battery, a second state parameter of the second battery and a second minimum single cell voltage of the second battery; determining a first initial allowable discharge power of the first battery according to the first state parameter, and determining a second initial allowable discharge power of the second battery according to the second state parameter; in the case that the first minimum single cell voltage is less than a first preset voltage, the first initial allowable discharge power is reduced to a first allowable discharge power, and the first preset voltage is the sum of a first discharge cutoff voltage of the first battery and a first voltage; in the case that the first minimum single cell voltage is greater than or equal to a second preset voltage, the first initial allowable discharge power is determined as the first allowable discharge power, and the second preset voltage is the sum of the first discharge cutoff voltage and a second voltage; in the case that the second minimum single cell voltage is less than a third preset voltage, the second initial allowable discharge power is reduced to a second allowable discharge power, and the third preset voltage is the sum of a second discharge cutoff voltage of the second battery and a third voltage; in the case that the second minimum single cell voltage is greater than or equal to a fourth preset voltage, the second initial allowable discharge power is determined as the second allowable discharge power, and the fourth preset voltage is the sum of the second discharge cutoff voltage and a fourth voltage; determining a target allowable discharge power of the battery system according to the first allowable discharge power and the second allowable discharge power, and controlling the battery system to discharge at the target allowable discharge power.

2. The method of claim 1, wherein, The first initial allowable discharge power is reduced to the first allowable discharge power in the case that the first minimum single cell voltage is less than the first preset voltage, comprising: determining a first target adjustment value of the first initial allowable discharge power according to the first minimum single cell voltage and according to a plurality of first corresponding relationships between a first single cell voltage and a first adjustment value; reducing the first initial allowable discharge power to the first allowable discharge power based on the first target adjustment value; The second initial allowable discharge power is reduced to the second allowable discharge power in the case that the second minimum single cell voltage is less than the third preset voltage, comprising: determining a second target adjustment value of the second allowable discharge power according to the second minimum single cell voltage and according to a plurality of second corresponding relationships between a second single cell voltage and a second adjustment value; reducing the second initial allowable discharge power to the second allowable discharge power based on the second target adjustment value.

3. The method according to claim 1 or 2, characterized in that, The first voltage is less than the second voltage, and / or the third voltage is less than the fourth voltage.

4. The method according to claim 1 or 2, characterized in that, The first initial allowable discharge power of the first battery is determined according to the first state parameter, and the second initial allowable discharge power of the second battery is determined according to the second state parameter, comprising: determining a first maximum discharge power of the first battery according to the first state parameter, and determining a second maximum discharge power of the second battery according to the second state parameter; determining the first initial allowable discharge power according to the first maximum discharge power, and determining the second initial allowable discharge power according to the second maximum discharge power.

5. The method of claim 4, wherein, The determining the first initial allowable discharge power according to the first maximum discharge power comprises: determining the first initial allowable discharge power according to the first maximum discharge power, and determining the second initial allowable discharge power according to the second maximum discharge power. The determining the second initial allowable discharge power according to the second maximum discharge power comprises: determining the first initial allowable discharge power according to the first maximum discharge power, and determining the second initial allowable discharge power according to the second maximum discharge power.

6. The method of claim 1 or 2, wherein, In a case where the first allowable discharge power is less than the second allowable discharge power, the target allowable discharge power is twice the first allowable discharge power; In a case where the second allowable discharge power is less than the first allowable discharge power, the target allowable discharge power is twice the second allowable discharge power.

7. A battery system characterized by, The battery system comprises a first battery and a second battery, and the battery system comprises independently arranged energy zones, the first battery and the second battery are arranged in different energy zones respectively, and the battery system comprises: a sampling unit configured to acquire a first state parameter of the first battery, a first minimum single-cell voltage of the first battery, a second state parameter of the second battery, and a second minimum single-cell voltage of the second battery; a control unit configured to determine a first initial allowable discharge power of the first battery according to the first state parameter, and determine a second initial allowable discharge power of the second battery according to the second state parameter; The control unit is further configured to, in a case where the first minimum single-cell voltage is less than a first preset voltage, reduce the first initial allowable discharge power to a first allowable discharge power, the first preset voltage being a sum of a first discharge cutoff voltage of the first battery and a first voltage, in a case where the first minimum single-cell voltage is greater than or equal to a second preset voltage, determine the first initial allowable discharge power as the first allowable discharge power, the second preset voltage being a sum of the first discharge cutoff voltage and a second voltage, in a case where the second minimum single-cell voltage is less than a third preset voltage, reduce the second initial allowable discharge power to a second allowable discharge power, the third preset voltage being a sum of a second discharge cutoff voltage of the second battery and a third voltage, and in a case where the second minimum single-cell voltage is greater than or equal to a fourth preset voltage, determine the second initial allowable discharge power as the second allowable discharge power, the fourth preset voltage being a sum of the second discharge cutoff voltage and a fourth voltage. The control unit is further configured to determine a target allowable discharging power of the battery system according to the first allowable discharging power and the second allowable discharging power, and control the battery system to discharge at the target allowable discharging power.

8. An electrical device, characterized by Comprising: a first load; a second load; The battery system according to claim 7, wherein the battery system is connected with the first load to provide first direct current to the first load, and / or the battery system is connected with the second load to provide second direct current to the second load, a voltage of the first direct current is greater than a voltage threshold, and a voltage of the second direct current is less than the voltage threshold.

9. A battery management system, characterized by, Comprising: a memory configured to store a program; a processor configured to execute the program stored in the memory, and when the program stored in the memory is executed, the processor is configured to execute the battery system discharging control method according to any one of claims 1 to 6.

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