Battery system discharge control method, battery system, electric device and battery management system

Abstract

The embodiment of the invention provides a battery system discharge control method, a battery system, a power utilization device and a battery management system. The possibility of over-discharge of a battery in the discharge process can be reduced. The battery system comprises a first battery and a second battery, the battery system comprises independently arranged energy areas, the first battery and the second battery are arranged in different energy areas, and the method comprises the following steps: acquiring a first state parameter and a second state parameter; determining first allowable discharge power of the first battery according to the first state parameter, and determining second allowable discharge power of the second battery according to the second state parameter; and determining 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 according to the target allowable discharge power.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a battery system discharging control method, a battery system, a power consumption device and a battery management system. BACKGROUND

[0002] The electric vehicle has been widely concerned since it was put into use. For the electric vehicle, the battery technology is an important factor for its development.

[0003] In the use process of the battery, over-discharge problem needs to be avoided. Therefore, how to reduce the possibility of over-discharge of the battery is an urgent problem to be solved. SUMMARY

[0004] The embodiments of the present application provide a battery system discharging control method, a battery system, a power consumption device and a battery management system, which can reduce the possibility of over-discharge of the battery in the discharging process.

[0005] In a first aspect, a battery system discharging control method is provided, the battery system includes a first battery and a second battery, the battery system includes independently arranged energy zones, the first battery and the second battery are arranged in different energy zones respectively, 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 discharging power of the first battery according to the first state parameter, and determining a second allowable discharging power of the second battery according to the second state parameter; determining a target allowable discharging power of the battery system according to the first allowable discharging power and the second allowable discharging power, and controlling the battery system to discharge at the target allowable discharging power.

[0006] In the embodiments of the present application, in the case that the battery system includes two batteries, the allowable discharging powers of the two batteries are determined according to the state parameters of the two batteries respectively, and then the target allowable discharging power of the entire battery system is determined based on the allowable discharging powers of the two batteries, so that the accuracy of the obtained target allowable discharging power is higher, and then the battery system is controlled to discharge based on the target discharging power, so that the possibility of over-discharge of the two batteries can be greatly reduced.

[0007] Further, the first battery and the second battery are arranged in different energy zones respectively, that is, the battery is redundantly designed, so that in the use process of the power consumption device, if one of the batteries is abnormal, the other battery can continue to supply power to the power consumption device, so that the power consumption device can continue to work normally.

[0008] In some possible implementation manners, the determining the first allowable discharging power of the first battery according to the first state parameter comprises: determining a first initial allowable discharging power of the first battery according to the first state parameter; obtaining a first minimum single-cell voltage of the first battery; and adjusting the first initial allowable discharging power according to the first minimum single-cell voltage to obtain the first allowable discharging power; and the determining the second allowable discharging power of the second battery according to the second state parameter comprises: determining a second initial allowable discharging power of the second battery according to the second state parameter; obtaining a second minimum single-cell voltage of the second battery; and adjusting the second initial allowable discharging power according to the second minimum single-cell voltage to obtain the second allowable discharging power.

[0009] Since the state parameter of the battery changes constantly during discharging, the initial allowable discharging power determined is adjusted according to the minimum single-cell voltage during discharging, so that the finally determined allowable discharging power can match the current state parameter of the battery, and the possibility of over-discharging of the battery can be further reduced.

[0010] In some possible implementation manners, the adjusting the first initial allowable discharging power according to the first minimum single-cell voltage to obtain the first allowable discharging power comprises: adjusting the first initial allowable discharging power according to the first minimum single-cell voltage and a first discharging cutoff voltage of the first battery to obtain the first allowable discharging power; and the adjusting the second initial allowable discharging power according to the second minimum single-cell voltage to obtain the second allowable discharging power comprises: adjusting the second initial allowable discharging power according to the second minimum single-cell voltage and a second discharging cutoff voltage of the second battery to obtain the second allowable discharging power.

[0011] According to the technical solution, the allowable discharging power is adjusted according to the discharging cutoff voltage of the two batteries in addition to the minimum single-cell voltage, that is, the allowable discharging power is adjusted according to more parameters, so that the accuracy of the finally obtained allowable discharging power is higher, and the possibility of over-discharging of the two batteries can be further reduced.

[0012] In some possible implementation manners, the adjusting the first initial allowable discharging power according to the first minimum cell voltage and the first discharging cutoff voltage of the first battery to obtain the first allowable discharging power comprises: in a case where the first minimum cell voltage is less than a first preset voltage, the first preset voltage being a sum of the first discharging cutoff voltage and a first voltage, reducing the first initial allowable discharging power to the first allowable discharging power; in a case where the first minimum cell voltage is greater than or equal to a second preset voltage, the second preset voltage being a sum of the first discharging cutoff voltage and a second voltage, determining the first initial allowable discharging power as the first allowable discharging power; and the adjusting the second initial allowable discharging power according to the second minimum cell voltage and the second discharging cutoff voltage of the second battery to obtain the second allowable discharging power comprises: in a case where the second minimum cell voltage is less than a third preset voltage, the third preset voltage being a sum of the second discharging cutoff voltage of the second battery and a third voltage, reducing the second initial allowable discharging power to the second allowable discharging power; in a case where the second minimum cell voltage is greater than or equal to a fourth preset voltage, the fourth preset voltage being a sum of the second discharging cutoff voltage and a fourth voltage, determining the second initial allowable discharging power as the second allowable discharging power.

[0013] The technical scheme can reduce the probability of overdischarging of the battery and thus under-voltage of the battery, by reducing the initial allowable discharging power in a case where the minimum cell voltage is less than the discharging cutoff voltage and a preset voltage, i.e., before the minimum cell voltage reaches the discharging cutoff voltage. In addition, the initial allowable discharging power is determined as the final allowable discharging power only in a case where the minimum cell voltage is greater than the discharging cutoff voltage and the preset voltage, thereby reducing the influence of the virtual voltage of the battery and further reducing the possibility of overdischarging of the battery.

[0014] In some possible implementation manners, the first initial allowable discharging power is reduced to the first allowable discharging power in the case that the first minimum single-cell voltage is less than a first preset voltage, including: determining a first target adjustment value of the first initial allowable discharging power according to the first minimum single-cell voltage and according to a plurality of first corresponding relationships between first single-cell voltages and first adjustment values; and reducing the first initial allowable discharging power to the first allowable discharging power based on the first target adjustment value; and the second initial allowable discharging power is reduced to the second allowable discharging power in the case that the second minimum single-cell voltage is less than a third preset voltage, including: determining a second target adjustment value of the second allowable discharging power according to the second minimum single-cell voltage and according to a plurality of second corresponding relationships between second single-cell voltages and second adjustment values; and reducing the second initial allowable discharging power to the second allowable discharging power based on the second target adjustment value.

[0015] The technical solution has a plurality of corresponding relationships between the first single-cell voltage and the first adjustment value, and also has a plurality of corresponding relationships between the second single-cell voltage and the second adjustment value, so that step-by-step power control can be implemented, the power adjustment is more accurate, the discharging efficiency can be ensured, and the possibility of over-discharging of the battery can be reduced.

[0016] In some possible implementation manners, 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 influence caused by the virtual voltage phenomenon of the battery, thereby effectively reducing the possibility of over-discharging of the battery. In addition, the first voltage and the second voltage have an interval value, and / or the third voltage and the fourth voltage have an interval value, so that the probability of repeatedly triggering the strategy of adjusting the allowable power can be reduced, and the discharging efficiency can be improved.

[0018] In some possible implementation manners, the first allowable discharging power of the first battery is determined according to the first state parameter, and the second allowable discharging power of the second battery is determined according to the second state parameter, including: determining a first maximum discharging power of the first battery according to the first state parameter, and determining a second maximum discharging power of the second battery according to the second state parameter; determining the first allowable discharging power according to the first maximum discharging power, and determining the second allowable discharging power according to the second maximum discharging power.

[0019] The technical scheme is characterized in that: firstly, the maximum discharge power of the two batteries is determined according to the state parameters; and then, the initial allowable discharge power of the two batteries is determined according to the maximum discharge power. Since the maximum discharge power and the allowable discharge power have a certain relationship, the initial allowable discharge power determined according to the maximum discharge power is relatively accurate, so that the probability of over-discharge of the two batteries can be further reduced.

[0020] In some possible implementation manners, the determining the first allowable discharge power according to the first maximum discharge power comprises: determining the first allowable discharge power according to the first maximum discharge power, and according to at least one of a fault condition of the battery system, a fault condition of the first battery, a voltage of the first battery, and an actual use power of the first battery; and the determining the second allowable discharge power according to the second maximum discharge power comprises: determining the second allowable discharge power according to the second maximum discharge power, and according to at least one of the fault condition of the battery system, a fault condition of the second battery, a voltage of the second battery, and an actual use power of the second battery.

[0021] The above technical scheme is characterized in that: the allowable discharge power of the first battery and the second battery is determined according to 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 implementation manners, 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; and 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.

[0023] If the first battery and the second battery are connected in series in the same loop, the first battery and the second battery will discharge according to the same current. If the allowable discharge current of one of the batteries is less than the discharge current, over-discharge may occur. Therefore, the target allowable discharge power is set to twice the minimum value of the two allowable discharge powers, so that the allowable discharge current of the two batteries is not less than the discharge current, thereby reducing the possibility of over-discharge.

[0024] In a second aspect, a battery system is provided, the battery system comprising a first battery and a second battery, the battery system comprising independently arranged energy zones, the first battery and the second battery being arranged in different energy zones respectively, the battery system comprising: 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 according to the first state parameter, determine a second allowable discharge power of the second battery according to the second state parameter, and determine a target allowable discharge power of the battery system according to the first allowable discharge power and the second allowable discharge power, and control the battery system to discharge at the target allowable discharge power.

[0025] In a third aspect, a power consuming device is provided, comprising: a first load; a second load; the battery system in the second aspect, the battery system being connected with the first load to provide a first direct current to the first load, and / or the battery system being connected with the second load to provide a second direct current to the second load, the first direct current having a voltage greater than a voltage threshold, and the second direct current having a voltage less than the voltage threshold.

[0026] In a fourth aspect, a battery management system is provided, comprising a processor and a memory, the memory being configured to store a computer program, and the processor being configured to invoke the computer program to execute the method in the first aspect or any of the implementation forms thereof.

[0027] In a fifth aspect, a computer readable storage medium is provided, configured to store a computer program, the computer program causing a computer to execute the method in the first aspect or any of the implementation forms thereof.

[0028] In a sixth aspect, a computer program product is provided, comprising: computer program instructions, the computer program instructions causing a computer to execute the method in the first aspect or any of the implementation forms thereof when the computer program instructions are executed by the computer. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 A schematic diagram of a battery comprising two energy zones is shown.

[0030] Figure 2 A schematic flow chart of a battery system discharge control method is shown.

[0031] Figure 3 A schematic diagram of a first battery and a second battery connected is shown.

[0032] Figure 4 A schematic flow chart of another battery system discharge control method is shown.

[0033] Figure 5 A flow chart of a specific battery system discharge control method according to an embodiment of the present application is shown.

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

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

[0036] Figure 8 A schematic diagram of a power consuming device according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0037] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some, but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application; the description and the drawings are to be regarded as illustrative in nature and are not intended to limit the application; the terminology used in the description and the claims herein and the above description of the drawings includes the terms specifically mentioned above as well as any equivalents thereof.

[0039] The orientation words appearing in the following description are the directions shown in the drawings, and are not intended to limit the specific structure of the present application. In the description of the present application, it should be further explained that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0040] Reference to an “embodiment” in this application means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. It is expressly understood that that the embodiments described in this application can be combined with each other in their various permutations and combinations.

[0041] “Multiple” appearing in this application refers to more than two (including two), and similarly, “multiple groups” refers to more than two groups (including two groups), and “multiple pieces” refers to more than two pieces (including two pieces).

[0042] In the field of new energy, as the main power source of electric devices such as motor vehicles, ships or spacecraft, the importance of batteries is self-evident. In order to further improve the performance and safety of the battery, multiple independently running energy zones can be set up, for example, as shown in Figure 1 two independent energy zones can be set up, so that multiple redundant designs and energy management such as high-voltage flexible power supply, low-voltage flexible power supply, thermal management redundancy, thermal runaway isolation can be achieved.

[0043] Setting up independent energy zones can ensure the stability of power output, reduce the possibility of affecting the electric device due to power failure, so that when a single zone fails, the other zone can maintain power supply, and the electric device can still operate normally. At the same time, dividing independent energy zones can also make the battery system design more flexible and be able to meet different use scenarios. For example, independent energy zones can be matched with different temperature performance of battery cells and partitioned for independent temperature control, so that the battery system can adapt to extremely cold and high temperature environments at the same time, so that the battery system can perform its performance in more working conditions.

[0044] At this time, the battery system of multiple energy zones (multiple battery packs) needs to avoid over-discharge of the battery during discharging. Over-discharge of the battery can cause many problems.

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

[0046] Secondly, it will cause the performance degradation of the battery, such as (1) capacity reduction; (2) internal resistance increase, which will cause more serious heating of the battery during charging and discharging, lower energy efficiency, and acceleration of the power supply device; (3) self-discharge rate increase.

[0047] Thirdly, it will cause system-level failure and affect user experience, such as (1) battery failure, the battery management system (BMS) will detect abnormal voltage of the over-discharged battery cell, and the BMS will lock the battery to prevent danger, resulting in the battery being unusable; (2) the power supply device cannot be used; (3) high maintenance cost.

[0048] Therefore, the embodiments of the present application provide a battery system discharge control method, the battery system includes a first battery and a second battery, the battery system includes independently arranged energy zones, the first battery and the second battery are arranged in different energy zones respectively, the method includes: obtaining 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 according to the first state parameter, and determining a second allowable discharge power of the second battery according to the second state parameter, then 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. In the case that the battery system includes two batteries, the allowable discharge power of the two batteries is determined according to the state parameters of the two batteries respectively, and then the target allowable discharge power of the entire battery system is determined based on the allowable discharge power of the two batteries, so that the accuracy of the obtained target allowable discharge power is higher, and then the battery system is discharged based on the target discharge power, so that the possibility of over-discharge of the two batteries can be greatly reduced.

[0049] Further, the first battery and the second battery are arranged in different energy zones respectively, that is, the battery is redundantly designed, so that in the use process of the power supply device, if one of the batteries is abnormal, the other battery can continue to supply power to the power supply device, so that the power supply device can continue to work normally.

[0050] The technical solutions described in the embodiments of the present application are applicable to various devices using batteries, for example, mobile phones, portable devices, notebook computers, electric vehicles, electric toys, electric tools, electric vehicles, ships and spacecraft, etc., for example, spacecraft includes airplanes, rockets, space shuttles and spacecraft, etc.

[0051] It should be understood that the technical solutions described in the embodiments of the present application are not only limited to the above described devices, but also applicable to all devices using batteries, but for the sake of brevity, the following embodiments are described taking electric vehicles as an example.

[0052] From the type of the battery, the battery in the embodiments of the present application can be any type of battery, including but not limited to: lithium ion battery, lithium metal battery, lithium sulfur battery, lead-acid battery, nickel-separation battery, nickel-hydrogen battery, lithium-air battery, sodium battery, etc. For example, the lithium ion battery can be a ternary battery, a lithium iron phosphate battery, etc. From the scale of the battery, the battery in the embodiments of the present application can be a battery module or a battery pack, etc. In the embodiments of the present application, the specific type and scale of the battery are not limited.

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

[0054] The method 200 can include at least part of the following contents.

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

[0056] S220: Determine a first allowable discharge power of the first battery according to the first state parameter, and determine a second allowable discharge power of the second battery according to the second state parameter.

[0057] S230: Determine a target allowable discharge power of the battery system according to the first allowable discharge power and the second allowable discharge power, and control the battery system to discharge at the target allowable discharge power.

[0058] In the embodiments of the present application, in the case that the battery system includes two batteries, the allowable discharge powers of the two batteries are determined according to the state parameters of the two batteries respectively, and then the target allowable discharge power of the entire battery system is determined based on the allowable discharge powers of the two batteries, so that the accuracy of the obtained target allowable discharge power is higher, and then the battery system is controlled to discharge based on the target discharge power, so that the possibility of over-discharge of the two batteries can be greatly reduced.

[0059] Further, the first battery and the second battery are arranged in different energy zones, i.e., the battery is redundantly designed, so that in the use process of the electric device, if one of the batteries is abnormal, the other battery can continue to supply power to the electric device, so that the electric device can continue to work normally.

[0060] The battery system can be composed of a battery and a battery management system. The battery system includes a first battery and a second battery, and the first battery and the second battery can be a battery pack, a battery module, or a battery set formed by electrically connecting battery monomers, etc.

[0061] The energy zone is a part in the battery system that can be independently operated and controlled. For example, each energy zone can be independently charged and discharged. The energy zones can be divided according to the arrangement of the batteries in the battery system. Alternatively, when the battery system includes one or more battery packs, the energy zones can be divided within each battery pack. The first battery and the second battery can be arranged in different energy zones in each battery pack. The energy zones can be separated by a partition beam to isolate the energy zones. Alternatively, when the battery system includes multiple battery packs, each battery pack can be an energy zone, and multiple energy zones can be formed between the battery packs.

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

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

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

[0065] The voltage converter can be a direct current / direct current (DC / DC) converter, a flyback converter, or other devices or circuits for realizing power input / output conversion. Alternatively, the DC / DC converter can be a unidirectional DC / DC converter, or it can also be a bidirectional DC / DC converter.

[0066] Figure 3 A schematic diagram of the connection between the first battery and the second battery is shown. By controlling the series switch module, the series connection and the parallel connection between the first battery and the second battery can be switched.

[0067] The embodiments of the present application do not specifically limit the types of the first battery and the second battery. The types of the first battery and the second battery can be consistent or inconsistent. The types of the battery cells inside the first battery can be consistent or inconsistent, and the types of the battery cells inside the second battery can be consistent or inconsistent.

[0068] In some embodiments, the type of the first battery can be inconsistent with the type of the second battery, as long as the outputs of the first battery and the second battery meet the system requirements.

[0069] For example, the first battery can be a power-type battery, and the second battery can be an energy-type battery. Alternatively, the first battery can be an energy-type battery, and the second battery can be a power-type battery.

[0070] The first battery and the second battery are set as different types of batteries, so that the battery system can meet different use scenarios, and the battery system can exert its performance in more working conditions.

[0071] The power type battery can provide power output to meet the demand for a large amount of energy in a short time, and can be used in the electric drive system of the power utilization device, such as acceleration and climbing. The energy type battery can store as much energy as possible, and can be used in the power utilization device with longer endurance mileage demand.

[0072] The first state parameter includes at least one of the temperature, voltage and current of the first battery, and the second state parameter includes at least one of the temperature, current and voltage of the second battery. The battery system includes 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 battery and the second battery can be set to be consistent.

[0074] In some embodiments, the first battery and the second battery can both be energy type batteries, or the first battery and the second battery can both be power type batteries. In this way, the first battery and the second battery are set as energy type batteries or power type batteries, so that the types of the first battery and the second battery are consistent, and the discharge rates are also consistent, thereby reducing the possibility of over-discharge of the batteries due to inconsistent discharge rates of the two batteries during discharge.

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

[0076] Alternatively, 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 the first state parameter can be obtained every preset time period, for example, 10 milliseconds (ms), 50 ms, 100 ms, 1 second (s) or the like.

[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 the second state parameter can be obtained every preset time period, for example, 10 ms, 50 ms, 100 ms, 1 s or the like.

[0078] In some embodiments, S220 can specifically include: determining the first maximum discharge power of the first battery according to the first state parameter, and determining the second maximum discharge power of the second battery according to the second state parameter, and determining the first allowable discharge power according to the first maximum discharge power, and determining the second allowable discharge power according to the second maximum discharge power.

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

[0080] Optionally, in the case that the first state parameter does not include the SOC of the first battery, the SOC of the first battery can be calculated according to the first state parameter, and then the first maximum discharge power can be determined according to the SOC of the first battery, the temperature, and the discharge power table.

[0081] Similarly, in the case that the second state parameter does not include the SOC of the second battery, the SOC of the second battery can be calculated according to the second state parameter, and then the second maximum discharge power can be determined according to the SOC of the second battery, the temperature, and the discharge power table.

[0082] After determining the first maximum discharge power and the second maximum discharge power, the first allowable discharge power can be determined according to the first maximum discharge power, and according to at least one of the fault condition of the battery system, the fault condition of the first battery, the voltage of the first battery, and the actual use power of the first battery.

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

[0084] The first allowable discharge power corresponding to the fault of the battery system or the first battery can be less than the first allowable discharge power corresponding to the non-fault, that is, if the battery system or the first battery is in a fault condition, the first allowable discharge power needs to be limited. For example, when the SOC of the first battery is 50% and the temperature of the first battery is 25℃, the first allowable discharge power is 100 kilowatts (KW). After the temperature of the first battery rises to 80℃, it indicates that the first battery has an over-temperature condition, and it can be considered that the first battery has a fault, and the first allowable discharge power needs to be limited, for example, the first allowable discharge power is limited to 70KW.

[0085] The fault condition can include but is not limited to overvoltage, undervoltage, overcurrent, overtemperature, low temperature, battery deformation, etc.

[0086] Similarly, the second allowable discharge power can be determined according to the second maximum discharge power and at least one of a fault condition of the battery system, a fault condition of the second battery, a voltage of the second battery, and an actual use power of the second battery.

[0087] According to the above parameters, the allowable discharge powers of the first battery and the second battery are determined respectively. Since the allowable discharge power is closely related to the above parameters, the accuracy of the determined allowable discharge power is high.

[0088] Considering that the state parameters of the battery change constantly during the discharging process, in order to make the finally determined allowable discharge power more accurate, in some embodiments, as shown in Figure 4 S220 can specifically include: S221a: determining a first initial allowable discharge power of the first battery according to the first state parameter; S222a: obtaining a 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 can specifically further include: S221b: determining a second initial allowable discharge power of the second battery according to the second state parameter; S222b: obtaining a second minimum single cell voltage of the second battery; S223b: adjusting the second initial allowable discharge power according to the second minimum single cell voltage to obtain the second allowable discharge power.

[0090] Since the state parameters of the battery change constantly during the discharging process, the initial allowable discharge power determined is adjusted according to the minimum single cell voltage during the discharging process, so that the finally determined allowable discharge power can match the current state parameters of the battery, and the possibility of over-discharge of the battery can be further reduced.

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

[0092] In some embodiments, determining the first initial allowable discharge power according to the first state parameter can specifically include: determining a first maximum discharge power of the first battery according to the first state parameter, and then determining the first allowable discharge power according to the first maximum discharge power.

[0093] Determining the second initial allowable discharge power according to the second state parameter can specifically include: determining a second maximum discharge power of the second battery according to the second state parameter, and then determining the second allowable discharge power according to the second maximum discharge power.

[0094] The technical scheme is characterized in that: the maximum discharge power of the two batteries is determined according to the state parameters, and then the initial allowable discharge power of the two batteries is determined according to the maximum discharge power, since the maximum discharge power and the allowable discharge power have a certain relationship, the initial allowable discharge power determined according to the maximum discharge power is more accurate, thereby further reducing the probability of over-discharge of the two batteries.

[0095] The specific implementation manner of determining the first initial allowable discharge power according to the first maximum discharge power can refer to the implementation manner of determining the first allowable discharge power according to the first maximum discharge power, and the specific implementation manner of determining the second initial allowable discharge power according to the second maximum discharge power can refer to the implementation manner of determining the second allowable discharge power according to the second maximum discharge power, which will not be described here.

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

[0097] In other embodiments, the first initial allowable discharge power is adjusted to the first allowable discharge power according to the first minimum single-cell voltage, which can specifically include: adjusting the first initial allowable discharge power to the first allowable discharge power according to the first minimum single-cell voltage and the first discharge cutoff voltage of the first battery. The second initial allowable discharge power is adjusted to the second allowable discharge power according to the second minimum single-cell voltage, which can specifically include: adjusting the second initial allowable discharge power to the second allowable discharge power according to the second minimum single-cell voltage and the second discharge cutoff voltage of the second battery.

[0098] The technical scheme is characterized in that: the technical scheme is characterized in that: the maximum discharge power of the two batteries is determined according to the state parameters, and then the initial allowable discharge power of the two batteries is determined according to the maximum discharge power, since the maximum discharge power and the allowable discharge power have a certain relationship, the initial allowable discharge power determined according to the maximum discharge power is more accurate, thereby further reducing the probability of over-discharge of the two batteries.

[0099] The discharge cutoff voltage refers to the lowest safety voltage at which the battery should stop discharging when the voltage drops to a certain specified value during discharging. The discharge cutoff voltage can be related to factors such as the chemical system of the battery, temperature, discharge rate, aging degree, and manufacturer's strategy. For example, the discharge cutoff voltage of a ternary lithium battery is different 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, and 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 maintained, i.e., the first initial allowable discharge power is determined as the first allowable discharge power.

[0101] For example, 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 cell voltage at the first time is 2 V. The first initial allowable discharge power can be reduced, for example, to 70 KW, and the first allowable discharge power at the first time is 70 KW. Then, the discharge is stopped, and the first minimum cell voltage rises to 3 V. At this time, the first minimum cell voltage is greater than the first discharge cutoff voltage, and the first allowable discharge power at the second time 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, and 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 maintained, i.e., the second initial allowable discharge power is determined as the second allowable discharge power.

[0103] During the dynamic discharge of the battery, due to the existence of instantaneous polarization and cumulative polarization, when the power is not empty (reflected as SOC still greater than 0), there is still a possibility of under-voltage due to rapid voltage reduction, thereby damaging the battery life and affecting the use of the electrical device. Therefore, power limitation can be intervened in advance before the minimum cell voltage reaches the discharge cutoff voltage to reduce the possibility of under-voltage.

[0104] In addition, after the battery stops discharging, the battery can have a voltage rebound phenomenon, i.e., the terminal voltage of the battery after stopping discharging can gradually rise to a relatively stable, higher value. For example, the voltage of the battery before discharging is 2.6 V, and after discharging, the voltage drops to 2.3 V. After a period of time, the battery voltage can rebound to 2.5 V or even 2.6 V. However, although the battery voltage rebounds to 2.5 V, 2.5 V at this time can be a virtual electric phenomenon, although it appears to be 2.5 V, the battery can not have a function of 2.5 V. In order to reduce the influence caused by the virtual electric phenomenon, the discharge allowable power can be restored to the initial discharge allowable power only when the minimum cell voltage is greater than the discharge cutoff voltage by a certain degree.

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

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

[0107] Adjusting the second initial allowable discharge power to the second allowable discharge power according to the second minimum cell voltage and the second discharge cutoff voltage can specifically include: in a case where the second minimum cell voltage is less than the third preset voltage, reducing the second initial allowable discharge power to the second allowable discharge power; in a case where the second minimum cell voltage is greater than or equal to the fourth preset voltage, determining the second initial allowable discharge power as the second allowable discharge power.

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

[0109] The technical solution, in a case where the minimum cell voltage is less than the discharge cutoff voltage and the preset voltage, that is, before the minimum cell voltage reaches the discharge cutoff voltage, intervenes in power limitation in advance, that is, reduces the initial allowable discharge power, so that the probability of over-discharge of the battery and then under-voltage can be reduced. In addition, in a case where the minimum cell voltage is greater than the discharge cutoff voltage and the preset voltage, the initial allowable discharge power is determined as the final allowable discharge power, so that the influence caused by the virtual voltage phenomenon of the battery can be reduced, and the possibility of over-discharge of the battery is further reduced.

[0110] Optionally, the first voltage and the second voltage can be determined based on at least one of an experience parameter, a direct current resistance (DCR) of the first battery, and a discharge map of the first battery. Similarly, the third voltage and the fourth voltage can be determined based on at least one of an experience parameter, a DCR of the second battery, and a 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 300 mV, or both be 400 mV.

[0112] Alternatively, the first voltage can be different from the second voltage. For example, the first voltage can be greater than the second voltage, and for another example, the first voltage can be less than the second voltage, such as 300 mV for the first voltage and 350 mV for the second voltage. Setting the second voltage to be greater than the first voltage can further reduce the impact caused by the pseudo voltage phenomenon of the battery, thereby effectively reducing the possibility of over-discharge of the battery. In addition, having a gap value, such as 50 mV, between the first voltage and the second voltage can reduce the probability of repeatedly triggering the strategy of adjusting the allowable power, thereby improving the discharge efficiency.

[0113] Likewise, the third voltage can also be the same as the fourth voltage, or can also be different. For example, the third voltage can be less than the fourth voltage. Setting the third voltage to be less than the fourth voltage can further reduce the impact caused by the pseudo voltage phenomenon of the battery, thereby effectively reducing the possibility of over-discharge of the battery. In addition, having a gap value, such as 50 mV, between the third voltage and the fourth voltage can reduce the probability of repeatedly triggering the strategy of adjusting the allowable power, thereby improving the discharge efficiency.

[0114] Alternatively, the first voltage can be the same as the third voltage, such as both being 300 mV, and the second voltage can be the same as the fourth voltage, such as both being 350 mV. 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] Alternatively, in the case where the first minimum cell voltage is less than the first preset voltage, how much the first initial allowable discharge power is reduced can be determined based on experience, or can also be determined based on the attribute parameters of the first battery, or can also be determined based on the application scenario of the first battery.

[0116] Likewise, in the case where the second minimum cell voltage is less than the second preset voltage, how much the second initial allowable discharge power is reduced can be determined based on experience, or can also be determined based on the attribute parameters of the second battery, or can also be determined 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 values of the first initial allowable discharge power can all be the same, i.e., the final first allowable discharge power is the same. Likewise, as long as the second minimum cell voltage is less than the second preset voltage, the adjustment values of the second initial allowable discharge power can also all be the same, i.e., the final second allowable discharge power is the same.

[0118] For example, when the first initial allowable discharging power is 100KW, the first preset voltage is 3.3V, and the first minimum single cell voltage is 3V, the first initial allowable discharging power is reduced by 20%, and the first allowable discharging power is 80KW. When the first minimum single cell voltage is 2.8V, the first initial allowable discharging power is also reduced by 20%, and the first allowable discharging power is also 80KW.

[0119] In some other embodiments, the first minimum single cell voltage can be divided into multiple levels, and the adjustment values corresponding to different levels are different. In other words, the first target adjustment value of the first initial allowable discharging power can be determined according to the first minimum single cell voltage and according to multiple first corresponding relationships between the first single cell voltage and the first adjustment value, and then the first initial allowable discharging power is reduced to the first allowable discharging power based on the first target adjustment value. And the second target adjustment value of the second initial allowable discharging power can be determined according to the second minimum single cell voltage and according to multiple second corresponding relationships between the second single cell voltage and the second adjustment value, and then the second initial allowable discharging power is reduced to the second allowable discharging power based on the second target adjustment value.

[0120] The technical scheme has multiple corresponding relationships between the first single cell voltage and the first adjustment value, and also has multiple corresponding relationships between the second single cell voltage and the second adjustment value, so that step-by-step power control can be realized, the power adjustment is more accurate, the discharging efficiency can be ensured, and the possibility of over-discharging of the battery can be reduced.

[0121] Optionally, the multiple first corresponding relationships can be determined based on the attribute parameter of the first battery, and the multiple second corresponding relationships can be determined based on the attribute parameter of the second battery.

[0122] For example, assuming that the first preset voltage is 3.3V, and the multiple first corresponding relationships include: when the first single cell voltage is less than 3.3V and greater than or equal to 3V, the first adjustment value is 40%; when the first single cell voltage is less than 3V and greater than or equal to 2.8V, the first adjustment value is 60%; and when the first single cell voltage is less than 2.8V, the first adjustment value is 80%. Wherein, the adjustment value a% means that the initial allowable discharging power is reduced by a%.

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

[0124] After the first allowable discharging power and the second allowable discharging power are determined, the target allowable discharging power of the battery system can be determined based on the first allowable discharging power and the second allowable discharging 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: P = min(first allowable discharge power, second allowable discharge power) * 2 (1) 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.

[0127] Then, the battery system can be controlled to discharge at the target allowable discharge power.

[0128] 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.

[0129] In 501a, the current and temperature of the first battery are obtained.

[0130] In 502a, the SOC of the first battery is calculated based on the current and temperature of the first battery.

[0131] 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.

[0132] In 504a, the first initial allowable discharge power of the first battery is obtained based on the first maximum discharge power.

[0133] In the 505a, the first minimum single cell voltage of the first battery is monitored in real time.

[0134] 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.

[0135] In 506a, the first initial allowable discharge power is reduced to obtain the first allowable discharge power.

[0136] In 507a, the first initial allowable discharge power is determined as the first allowable discharge power.

[0137] In 501b, the current and temperature of the second battery are acquired.

[0138] In 502b, the SOC of the second battery is calculated according to the current and temperature of the second battery.

[0139] In 503b, the second maximum discharge power of the second battery is obtained by searching the power table according to the SOC and temperature of the second battery.

[0140] In 504b, the second initial allowable discharge power of the second battery is obtained according to the second maximum discharge power.

[0141] In 505b, the second minimum single cell voltage of the second battery is monitored in real time.

[0142] If the second minimum single cell voltage is < (the second discharge cutoff voltage + 300 mV), step 506b is performed. If the second minimum single cell voltage is ≥ (the second discharge cutoff voltage + 350 mV), step 507b is performed.

[0143] In 506b, the second initial allowable discharge power is reduced to obtain the second allowable discharge power.

[0144] In 507b, the second initial allowable discharge power is determined as the second allowable discharge power.

[0145] In 508, the target allowable discharge power is determined based on the first allowable discharge power and the second allowable discharge power.

[0146] For example, the target discharge power can be calculated according to formula (1).

[0147] Wherein, 501a-507a and 501b-507b can be executed simultaneously, for example, steps 501a and 501b can be executed simultaneously, and steps 502a and 502b can be executed simultaneously.

[0148] In the embodiments of the present application, the size of the serial number of each process does not mean the order of execution, the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0149] Furthermore, the various embodiments described in the present application and / or the technical features in each embodiment can be combined with each other as long as there is no conflict, and the technical scheme obtained after combination should also fall within the protection scope of the present application.

[0150] The battery system discharge control method of the embodiments of the present application is described in detail above, and the battery system of the embodiments of the present application will be described below. It should be understood that the battery system in the embodiments of the present application can perform the battery system discharge control method in the embodiments of the present application.

[0151] Figure 6 A schematic block diagram of the battery system 600 of the embodiments of the present application is shown, the battery system 600 includes a first battery and a second battery, and the battery system includes independently arranged energy zones, and the first battery and the second battery are arranged in different energy zones respectively. As shown in the figure, Figure 6 The battery system 600 includes: The sampling unit 610 is configured to acquire a first state parameter of the first battery and a second state parameter of the second battery.

[0152] The control unit 620 is configured to determine a first allowable discharge power of the first battery according to the first state parameter, determine a second allowable discharge power of the second battery according to the second state parameter, and determine a target allowable discharge power of the battery system according to the first allowable discharge power and the second allowable discharge power, and control the battery system 600 to discharge at the target allowable discharge power.

[0153] Optionally, in the embodiments of the present application, the sampling unit 610 is further configured to acquire a first minimum single cell voltage of the first battery; and the control unit 620 is specifically configured to determine a first initial allowable discharge power of the first battery according to the first state parameter, and adjust the first initial allowable discharge power according to the first minimum single cell voltage to obtain the first allowable discharge power.

[0154] The sampling unit 610 is further configured to acquire a second minimum single cell voltage of the second battery; and the control unit 620 is specifically configured to determine a 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.

[0155] Optionally, in the embodiments of the present 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 a first discharge cutoff voltage of the first battery to obtain the first allowable discharge power, and adjust the second initial allowable discharge power according to the second minimum single cell voltage and a second discharge cutoff voltage of the second battery to obtain the second allowable discharge power.

[0156] Optionally in the embodiments of the present application, the control unit 620 is specifically configured to: in a case where the first minimum single cell voltage is less than a first preset voltage, the first preset voltage being a sum of the first discharge cutoff voltage and a first voltage, reduce the first initial allowable discharge power to the first allowable discharge power; in a case where the first minimum single cell voltage is greater than or equal to a second preset voltage, the second preset voltage being a sum of the first discharge cutoff voltage and a second voltage, determine the first initial allowable discharge power as the first allowable discharge power.

[0157] The control unit 620 is specifically configured to: in a case where the second minimum single cell voltage is less than a third preset voltage, the third preset voltage being a sum of a second discharge cutoff voltage of the second battery and a third voltage, reduce the second initial allowable discharge power to the second allowable discharge power; in a case where the second minimum single cell voltage is greater than or equal to a fourth preset voltage, the fourth preset voltage being a sum of the second discharge cutoff voltage and a fourth voltage, determine the second initial allowable discharge power as the second allowable discharge power.

[0158] Optionally in the embodiments of the present application, the control unit 620 is further configured to: determine 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 first single cell voltages and first adjustment values; and reduce the first initial allowable discharge power to the first allowable discharge power based on the first target adjustment value.

[0159] The control unit 620 is further configured to: determine 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 second single cell voltages and second adjustment values; and reduce the second initial allowable discharge power to the second allowable discharge power based on the second target adjustment value.

[0160] Optionally in the embodiments of the present application, the first voltage is less than the second voltage, and / or the third voltage is less than the fourth voltage.

[0161] Optionally in the embodiments of the present application, the control unit 620 is specifically configured to: determine a first maximum discharge power of the first battery according to the first state parameter, and determine a second maximum discharge power of the second battery according to the second state parameter; determine the first allowable discharge power according to the first maximum discharge power, and determine the second allowable discharge power according to the second maximum discharge power.

[0162] Optionally, in the embodiment of the present application, the control unit 620 is specifically configured to: determine the first allowable discharge power according to the first maximum discharge power, and according to at least one of a fault condition of the battery system, a fault condition of the first battery, a voltage of the first battery, and an actual use power of the first battery; and determine the second allowable discharge power according to the second maximum discharge power, and according to at least one of a fault condition of the battery system, a fault condition of the second battery, a voltage of the second battery, and an actual use power of the second battery.

[0163] Optionally, in the embodiment of the present 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; and 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.

[0164] It should be understood that the battery system 600 can implement the corresponding operations in the battery system discharge control method 200, and details are not described herein for brevity.

[0165] Figure 7 FIG. 7 is a hardware structure schematic diagram of a battery management system 700 according to an embodiment of the present application. The battery management system 700 includes a memory 710, a processor 720, a communication interface 730, and a bus 740. The memory 710, the processor 720, and the communication interface 730 are communicatively connected to each other through the bus 740.

[0166] The memory 710 can be a read-only memory (ROM), a static storage device, and a random access memory (RAM). The memory 710 can 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 configured to perform each step of the battery system discharge control method according to an embodiment of the present application.

[0167] The processor 720 can be a general-purpose central processing unit (CPU), a microprocessor, an application specific integrated circuit (ASIC), a graphics processing unit (GPU), or one or more integrated circuits, configured to execute related programs to implement the functions required by the units in the battery management system 700 according to an embodiment of the present application, or to execute the battery system discharge control method according to an embodiment of the present application.

[0168] The processor 720 can also be an integrated circuit chip having a processing capability for signals. In implementation, each step of the battery system discharge control method of the embodiments of the present application can be completed by integrated logic circuits of hardware or instructions in the form of software in the processor 720.

[0169] The processor 720 described above can also be a general processor, a digital signal processor (DSP), an ASIC, a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component. Each method, step and logic block diagram disclosed in the embodiments of the present application can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed in the embodiments of the present application can be directly embodied as hardware processor execution or executed by a combination of hardware and software modules in the processor. The software module can be located in a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register or other mature storage medium in the art. The storage medium is located in the memory 710, and the processor 720 reads the information in the memory 710, and combines the hardware to complete the functions required by the units included in the battery management system 700 of the embodiments of the present application, or executes the battery system discharge control method of the embodiments of the present application.

[0170] The communication interface 730 uses a transceiver such as but not limited to a transceiver to realize the communication between the battery management system 700 and other devices or communication networks.

[0171] The bus 740 can include a path for transmitting information between each component (for example, the memory 710, the processor 720, the communication interface 730) of the battery management system 700.

[0172] It should be noted that although the above battery management system 700 only shows the memory, the processor and the communication interface, in the specific implementation, those skilled in the art should understand that the battery management system 700 can also include other devices necessary for normal operation. At the same time, according to the specific needs, those skilled in the art should understand that the battery management system 700 can also include hardware devices for realizing other additional functions. In addition, those skilled in the art should understand that the battery management system 700 can also only include the devices necessary for the embodiments of the present application, and does not have to include all the devices shown in the above. Figure 7

[0173] As Figure 8 ​As shown, the embodiment of the present application further provides a power consuming device 800, which comprises a first load 810, a second load 820 and a battery system 830, wherein the battery system 830 is connected with the first load 810, and is configured to provide first direct current for the first load 810, and / or the battery system 830 is connected with the second load 820, and is configured to provide second direct current for the second load 820, 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.

[0174] That is, the first load 810 is a high-voltage load, the second load 820 is a low-voltage load, and the battery system 830 is configured to provide low-voltage power supply for the first load 810 and high-voltage power supply for the second load 820.

[0175] Optionally, the power consuming device 800 can be an electric vehicle, and the battery system 830 can be the battery system 600.

[0176] The embodiment of the present application further provides a computer readable storage medium, configured to store a computer program, the computer program being configured to execute the method of the various embodiments of the present application.

[0177] The computer readable storage medium described above can be a transitory computer readable storage medium or a non-transitory computer readable storage medium.

[0178] The embodiment of the present application further provides a computer program product, which comprises a computer program stored in a computer readable storage medium, and the computer program comprises program instructions, when the program instructions are executed by a computer, the computer is caused to execute the battery system discharge control method.

[0179] Although the present application has been described with reference to the preferred embodiments, various modifications can be made to the present application without departing from the scope of the present application, and equivalent substitutions can be made to the components thereof. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present 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 and a second state parameter of the second battery, determining a first allowable discharge power of the first battery according to the first state parameter, and determining a second allowable discharge power of the second battery according to the second state parameter; 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 allowable discharge power of the first battery is determined according to the first state parameter, comprising: determining a first initial allowable discharge power of the first battery according to the first state parameter; obtaining a first minimum single cell voltage of the first battery; adjusting the first initial allowable discharge power according to the first minimum single cell voltage to obtain the first allowable discharge power; The second allowable discharge power of the second battery is determined according to the second state parameter, comprising: determining a second initial allowable discharge power of the second battery according to the second state parameter; obtaining a second minimum single cell voltage of the second battery; adjusting the second initial allowable discharge power according to the second minimum single cell voltage to obtain the second allowable discharge power.

3. The method of claim 2, wherein, The first initial allowable discharge power of the first battery is adjusted according to the first minimum single cell voltage and the first discharge cutoff voltage of the first battery to obtain the first allowable discharge power, comprising: 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 the first allowable discharge power, and the first preset voltage is the sum of the first discharge cutoff voltage 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; The second initial allowable discharge power of the second battery is adjusted according to the second minimum single cell voltage and the second discharge cutoff voltage of the second battery to obtain the second allowable discharge power, comprising:

4. The method of claim 3, wherein, 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 the second allowable discharge power, and the third preset voltage is the sum of the second discharge cutoff voltage 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. ​ ​ in a case where the second minimum single cell voltage is less than a third preset voltage, the second initial allowable discharging power is reduced to the second allowable discharging power, the third preset voltage being a sum of the second discharging cut-off voltage and a third voltage; in a case where the second minimum single cell voltage is greater than or equal to a fourth preset voltage, the second initial allowable discharging power is determined as the second allowable discharging power, the fourth preset voltage being a sum of the second discharging cut-off voltage and a fourth voltage.

5. The method of claim 4, wherein, the first initial allowable discharging power is reduced to the first allowable discharging power in a case where the first minimum single cell voltage is less than a first preset voltage, including: a first target adjustment value of the first initial allowable discharging power is determined according to the first minimum single cell voltage and according to a plurality of first corresponding relationships between first single cell voltages and first adjustment values; the first initial allowable discharging power is reduced to the first allowable discharging power based on the first target adjustment value; the second initial allowable discharging power is reduced to the second allowable discharging power in a case where the second minimum single cell voltage is less than a third preset voltage, including: a second target adjustment value of the second allowable discharging power is determined according to the second minimum single cell voltage and according to a plurality of second corresponding relationships between second single cell voltages and second adjustment values; the second initial allowable discharging power is reduced to the second allowable discharging power based on the second target adjustment value.

6. The method according to claim 4 or 5, characterized in that, the first voltage is less than the second voltage, and / or, the third voltage is less than the fourth voltage.

7. The method according to any one of claims 1 to 5, characterized in that, the first allowable discharging power of the first battery is determined according to the first state parameter, and the second allowable discharging power of the second battery is determined according to the second state parameter, including: a first maximum discharging power of the first battery is determined according to the first state parameter, and a second maximum discharging power of the second battery is determined according to the second state parameter; the first allowable discharging power is determined according to the first maximum discharging power, and the second allowable discharging power is determined according to the second maximum discharging power.

8. The method of claim 7, wherein, the first allowable discharging power is determined according to the first maximum discharging power and according to at least one of a fault condition of the battery system, a fault condition of the first battery, a voltage of the first battery and an actual use power of the first battery; the second allowable discharging power is determined according to the second maximum discharging power and according to at least one of a fault condition of the battery system, a fault condition of the second battery, a voltage of the second battery and an actual use power of the second battery. in a case where the first allowable discharging power is less than the second allowable discharging power, the target allowable discharging power is twice the first allowable discharging power; ​ 9. The method according to any one of claims 1 to 5, characterized in that, ​ In a case where the second allowable discharging power is less than the first allowable discharging power, the target allowable discharging power is 2 times the second allowable discharging power.

10. A battery system characterized by, The battery system includes a first battery and a second battery, and includes independently arranged energy zones, the first battery and the second battery are arranged in different energy zones respectively, and the battery system includes: 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 discharging power of the first battery according to the first state parameter, determine a second allowable discharging power of the second battery according to the second state parameter, and 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.

11. An electrical device, characterized by comprising: a first load; a second load; The battery system according to claim 10 is connected with the first load to provide first direct current for the first load, and / or the battery system is connected with the second load to provide second direct current for the second load, 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.

12. 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 9.

Images