Application Method and Device of Battery Module, Storage Medium and Battery Module

Abstract

The embodiments of the present application provide a method and apparatus for applying a battery module, a storage medium, and a control device. The embodiments of the present application provide a method for applying a battery module, comprising: determining the state of charge (SOC) of battery cells in at least one of a first branch and a second branch of the battery module based on the charge and discharge state of the battery module; determining an extreme value of the SOC based on the charge and discharge state of the battery module; determining a circulating current amount circulating between the first branch and the second branch; and performing a protection operation based on the circulating current amount and the extreme value of the SOC.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to an application method and device for a battery module, a storage medium, and a control device. Background Art

[0002] With the development of battery technology, battery capacity is getting larger and larger and its application range is getting wider and wider.

[0003] In related technologies, for battery modules containing multiple branches, charging is stopped when the charging circuit reaches a cutoff voltage, or discharging is stopped when the discharging circuit reaches a cutoff voltage to protect the battery module. However, in actual battery module use, individual battery cells are still particularly prone to failure. Summary of the Invention

[0004] The present application provides a battery module application method and device, a storage medium, and a control device, which at least partially solve the problem that individual cells on a branch line are prone to failure.

[0005] In a first aspect, an embodiment of the present application provides an application method of a battery module, comprising:

[0006] Determining a state of charge (SOC) of a battery cell on at least one of a first branch and a second branch of the battery module;

[0007] Determining an extreme value of the SOC according to a charge and discharge state of the battery module;

[0008] determining a circulating amount of electricity circulating between the first branch and the second branch;

[0009] A protection operation is performed according to the extreme values of the circulating current and the SOC.

[0010] In an embodiment of the present application, the SOC of at least one branch is determined based on the charge and discharge status of the battery module, and the extreme value of the SOC is determined based on the discharge status, thereby determining the circulating amount between the first branch and the second branch. According to the extreme values of the circulating amount and the SOC, corresponding protection operations are performed, thereby reducing the problem of overcharging or over-discharging of battery cells caused by circulation.

[0011] In some embodiments, the OCV of the first branch is higher than the OCV of the second branch;

[0012] Determining the extreme value of the SOC according to the charge and discharge state of the battery module includes:

[0013] When the battery module is in a charging state, determining a maximum SOC value of the battery cell on the second branch;

[0014] When the battery module is in a discharging state, a minimum SOC value of the battery cell on the first branch is determined.

[0015] When the battery module is in a discharging state, the high OCV branch will subsequently discharge to the low OCV branch. Since the battery module was previously in a discharging state, some individual battery cells may be over-discharged. In the embodiment of the present application, protection operations are performed based on the minimum SOC value and the circulating current charge to reduce this over-discharge problem. If the battery module was previously in a charging state, the maximum SOC value of the second branch being charged by the circulating current is determined at this time, which can reduce the overcharging of the battery cells in the second branch.

[0016] Based on the above solution, the battery protection operation is performed according to the circulating power and the SOC, including:

[0017] When the circulating current and the SOC reach maximum values, determining a first moment when the SOC of the battery cell corresponding to the maximum SOC value reaches a first preset value;

[0018] At the first moment, charging of the battery module is stopped.

[0019] In the embodiment of the present application, the first moment is determined in advance, and then the charging of the battery module is stopped at the first moment. In this way, even if the first branch discharges to the second branch in a circular manner, the phenomenon of the battery cell process with the maximum SOC on the second branch can be avoided.

[0020] The performing of a protection operation according to the extreme values of the circulating current and the SOC includes:

[0021] When the circulating current and the SOC are at their minimum values, determining a second moment when the battery cell corresponding to the minimum SOC value reaches a second preset value;

[0022] According to the second moment, a protection operation is performed.

[0023] By determining the second moment, even if there is circulating discharge at the end of discharge, the cut-off discharge moment (i.e., the second moment) at which the circulating discharge may cause over-discharge is estimated in advance, and the protection operation is performed according to the second moment, which can at least avoid over-discharge.

[0024] In some embodiments, performing a protection operation according to the second moment includes at least one of the following:

[0025] At the second moment, stopping the discharge of the first branch;

[0026] At the second moment, stopping the discharge of the battery module;

[0027] At or before the second moment, a reminder message is output.

[0028] The protection operation performed at the second moment can reduce the over-discharge phenomenon.

[0029] In some embodiments, the reminder information includes:

[0030] Charging reminder information;

[0031] and / or

[0032] Change reminder information.

[0033] By outputting reminder information, the user can be informed to stop discharging the battery module or replace the battery cells in time, thereby protecting the entire battery module.

[0034] In some embodiments, determining the circulating current amount discharged from the first branch to the second branch includes:

[0035] The circulating current amount required for the first branch to discharge to the second branch is determined when the OCV difference between the first branch and the second branch reaches a preset range.

[0036] The circulating current power is estimated in advance based on the circulating current power discharged from the first branch with high OCV to the second branch with low OCV when the OCV difference between the two branches is small enough, that is, within a preset range.

[0037] In some embodiments, the OCV of the first branch is higher than the OCV of the second branch;

[0038] The determining the circulating current amount required for the first branch to discharge to the second branch when the OCV difference between the first branch and the second branch reaches a preset range includes:

[0039] determining an OCV difference between the first branch and the second branch after each transfer of a preset amount of electricity from the first branch to the second branch;

[0040] When the OCV difference is within the preset range, the circulating power is determined according to the number of times the preset power is transferred from the first branch to the second branch.

[0041] In the embodiment of the present application, by predicting the change in the OCV difference between the two branches that transfer the preset amount of electricity, the circulating electricity can be easily determined based on the number of simulation executions.

[0042] In some embodiments, determining the circulating current amount required for the first branch to discharge to the second branch when the OCV difference between the first branch and the second branch reaches a preset range includes:

[0043] Determining, based on the m+1th SOC difference between the SOCs of the first branch and the SOCs of the second branch after transferring charge m times, the m+1th OCV difference between the first branch and the second branch after transferring charge from the first branch to the second branch by a preset ratio of the m+1th SOC difference; wherein m is 0 or a positive integer;

[0044] When the (m+1)th OCV difference is within the preset range, the sum of the (m+1) times transferred electricity is determined as the circulating current electricity.

[0045] By predicting the change of the OCV difference between the two branches based on the power transfer with each damage ratio, the circulating power can be determined more quickly with less calculation.

[0046] In some embodiments, determining the SOC of the battery cells on the first branch and the second branch of the battery module further includes:

[0047] When the SOC of the battery module reaches a third preset value, the SOCs of the battery cells in the first branch and the second branch of the battery module are determined.

[0048] In the embodiment of the present application, the SOC of the battery cells on the first branch and the second branch of the battery module is determined only when the SOC of the battery module reaches a third preset value, thereby reducing the amount of calculation required for calculating the circulating current.

[0049] In some embodiments, the method further comprises:

[0050] The third preset value is determined according to at least one of the charge and discharge state of the battery module, the environmental parameter of the first branch, and the environmental parameter of the second branch.

[0051] In some embodiments, the third preset value may be a pre-set static value, and in the embodiment of the present application, it is a dynamic value determined dynamically, so that a third preset value suitable for different environments can be determined.

[0052] In a second aspect, an embodiment of the present application provides an application device of a battery module, comprising:

[0053] A first determining module is configured to determine the state of charge (SOC) of a battery cell on at least one of the first branch and the second branch of the battery module;

[0054] A second determining module is configured to determine an extreme value of the SOC according to a charge and discharge state of the battery module;

[0055] a third determining module, configured to determine a circulating amount of electricity circulating between the first branch and the second branch;

[0056] An execution module is used to execute a protection operation according to the extreme values of the circulating current and the SOC.

[0057] In an embodiment of the present application, the SOC of at least one branch is determined based on the charge and discharge status of the battery module, and the extreme value of the SOC is determined based on the discharge status, thereby determining the circulating amount between the first branch and the second branch. According to the extreme values of the circulating amount and the SOC, corresponding protection operations are performed, thereby reducing the problem of overcharging or over-discharging of battery cells caused by circulation.

[0058] In some embodiments, the OCV of the first branch is higher than the OCV of the second branch;

[0059] The second determination module is used to determine the maximum SOC value of the battery cell on the second branch when the battery module is in a charging state; and to determine the minimum SOC value of the battery cell on the first branch when the battery module is in a discharging state.

[0060] When the battery module is in a discharging state, the high OCV branch will subsequently discharge to the low OCV branch. Since the battery module was previously in a discharging state, some individual battery cells may be over-discharged. In the embodiment of the present application, protection operations are performed based on the minimum SOC value and the circulating current charge to reduce this over-discharge problem. If the battery module was previously in a charging state, the maximum SOC value of the second branch being charged by the circulating current is determined at this time, which can reduce the overcharging of the battery cells in the second branch.

[0061] In some embodiments, the execution module is used to determine the first moment when the SOC of the battery cell corresponding to the maximum SOC value reaches a first preset value when the circulating current power and the SOC reach maximum values; at the first moment, stop charging the battery module.

[0062] In the embodiment of the present application, the first moment is determined in advance, and then the charging of the battery module is stopped at the first moment. In this way, even if the first branch discharges to the second branch in a circular manner, the phenomenon of the battery cell process with the maximum SOC on the second branch can be avoided.

[0063] In some embodiments, the execution module is configured to determine a second moment when the circulating current and the SOC have minimum values, when the battery cell corresponding to the minimum SOC value reaches a second preset value; and execute a protection operation according to the second moment.

[0064] By determining the second moment, even if there is circulating discharge at the end of discharge, the cut-off discharge moment (i.e., the second moment) at which the circulating discharge may cause over-discharge is estimated in advance, and the protection operation is performed according to the second moment, which can at least avoid over-discharge.

[0065] In some embodiments, the execution module specifically performs at least one of the following:

[0066] At the second moment, stopping the discharge of the first branch;

[0067] At the second moment, stopping the discharge of the battery module;

[0068] At or before the second moment, a reminder message is output.

[0069] The protection operation performed at the second moment can reduce the over-discharge phenomenon.

[0070] In some embodiments, the reminder information includes:

[0071] Charging reminder information;

[0072] and / or

[0073] Change reminder information.

[0074] By outputting reminder information, the user can be informed to stop discharging the battery module or replace the battery cells in time, thereby protecting the entire battery module.

[0075] In some embodiments, the third determination module is configured to determine the circulating current amount required to be discharged from the first branch to the second branch when the difference in OCV between the first branch and the second branch falls within a preset range. The pre-estimated circulating current amount is the circulating current amount to be discharged from the first branch with a higher OCV to the second branch with a lower OCV when the difference in OCV between the two branches is sufficiently small, i.e., within the preset range.

[0076] In some embodiments, the OCV of the first branch is higher than the OCV of the second branch;

[0077] The third determination module is specifically used to determine the OCV difference between the first branch and the second branch after each time the first branch transfers a preset amount of electricity to the second branch; when the OCV difference is within the preset range, the circulating current amount is determined based on the number of times the first branch transfers the preset amount of electricity to the second branch.

[0078] In the embodiment of the present application, by predicting the change in the OCV difference between the two branches that transfer the preset amount of electricity, the circulating electricity can be easily determined based on the number of simulation executions.

[0079] In some embodiments, the third determination module is specifically configured to determine the SOCs of the battery cells on the first branch and the second branch of the battery module when the SOC of the battery module reaches a third preset value.

[0080] By predicting the change of the OCV difference between the two branches based on the power transfer with each damage ratio, the circulating power can be determined more quickly with less calculation.

[0081] In some embodiments, the apparatus further comprises:

[0082] The fourth determination module is configured to determine the third preset value based on at least one of the charge and discharge state of the battery module, the environmental parameters of the first branch, and the environmental parameters of the second branch. In this embodiment of the present application, the SOC of the battery cells in the first and second branches of the battery module is determined only when the SOC of the battery module reaches the third preset value, thereby reducing the computational complexity associated with calculating the circulating current.

[0083] In a third aspect, an embodiment of the present application provides a power supply module, including:

[0084] a memory storing computer-executable instructions;

[0085] A processor is connected to the memory and is used to implement the application method of the battery module provided by any of the aforementioned technical solutions by executing the computer-executable instructions.

[0086] In an embodiment of the present application, the SOC of at least one branch is determined based on the charge and discharge status of the battery module, and the extreme value of the SOC is determined based on the discharge status, thereby determining the circulating amount between the first branch and the second branch. According to the extreme values of the circulating amount and the SOC, corresponding protection operations are performed, thereby reducing the problem of overcharging or over-discharging of battery cells caused by circulation.

[0087] In a fourth aspect, the fourth aspect of the embodiment of the present application provides a computer storage medium, which is characterized in that computer executable instructions are stored on the computer medium, and after the computer executable instructions are executed, the application method of the battery module provided by any of the aforementioned technical solutions can be implemented.

[0088] In an embodiment of the present application, the SOC of at least one branch is determined based on the charge and discharge status of the battery module, and the extreme value of the SOC is determined based on the discharge status, thereby determining the circulating amount between the first branch and the second branch. According to the extreme values of the circulating amount and the SOC, corresponding protection operations are performed, thereby reducing the problem of overcharging or over-discharging of battery cells caused by circulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0090] Figure 1 This is a schematic structural diagram of a vehicle disclosed in one embodiment of the present application;

[0091] Figure 2 This is a flow chart of a method for applying a battery module disclosed in one embodiment of the present application;

[0092] Figure 3 This is a schematic structural diagram of a battery module disclosed in one embodiment of the present application;

[0093] Figure 4A This is a flow chart of a method for applying a battery module provided in one embodiment of the present application;

[0094] Figure 4B This is a flow chart of a method for applying a battery module provided in one embodiment of the present application;

[0095] Figure 5 This is a structural diagram of an application device of a battery module provided in one embodiment of the present application. DETAILED DESCRIPTION

[0096] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0097] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0098] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0099] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0100] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0101] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0102] The term "plurality" used in this application refers to two or more (including two).

[0103] Research has found that after a battery module is fully charged or discharged, circulating currents may still exist between different branches. This circulating current refers to discharge from a branch with a high open circuit voltage (OCV) to a branch with a lower OCV. However, a single branch may contain multiple battery cells with varying states of charge (SOC). For a branch with a high OCV, the SOC of a single cell may be low, leading to over-discharge. For a branch with a lower OCV, the SOC of a single cell may be high, leading to over-charge.

[0104] In view of this, in this application, when charging and discharging the battery module, the circulating current between the two branches is taken into consideration in advance, and protection operations are performed based on the extreme values of the circulating current and the SOC of a single battery cell. By executing the protection operation, the over-discharge or over-charge of a single battery cell caused by the circulation between the two branches is reduced, thereby extending the service life of the battery module.

[0105] The battery module application method provided in the embodiments of the present application can be applied to various battery modules including multiple branches. One branch of the battery module can be configured with one or more battery cells. These battery cells can be connected in series or parallel and then output power together.

[0106] The battery module can be applied to various electrical devices and can supply high current to the electrical devices through multiple branches. Figure 1 The utility model relates to an electric device comprising the battery module.

[0107] The electrical devices disclosed in the embodiments of the present application can be used in, but are not limited to, electrical devices such as vehicles, ships, or aircraft. The electrical devices can include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, battery-powered vehicles, electric cars, ships, spacecraft, and the like. Electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, among others.

[0108] like Figure 2 As shown, an application method of a battery module in an embodiment of the present application includes:

[0109] S110: Determine the state of charge (SOC) of a battery cell in at least one of a first branch and a second branch of the battery module according to the charge and discharge state of the battery module;

[0110] S120: Determine an extreme value of the SOC according to the charge and discharge state of the battery module;

[0111] S130: Determine the circulating current amount between the first branch and the second branch;

[0112] S140: Executing a protection operation according to the extreme values of the circulating current and the SOC.

[0113] The battery module includes but is not limited to various power battery modules (or secondary battery modules), which can be charged and discharged multiple times. Typical battery modules include but are not limited to lithium battery modules or sodium battery modules.

[0114] The battery cell may be one of the components of a battery module. In the present application, the battery cell may include a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery or a magnesium-ion battery, etc., and the embodiments of the present application do not limit this. The battery cell may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this. Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application do not limit this.

[0115] The battery referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may include a battery module or a battery pack. A battery generally includes a casing that encloses one or more battery cells. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0116] refer to Figure 3 As shown, a battery module may include at least two parallel branches. For example, taking two branches as an example, a first branch and a second branch may be two parallel branches. Each of these two branches may be connected to at least one battery cell. For example, each branch may be connected in series with multiple battery cells. Typically, the battery cells in a battery module have the same specifications. A battery module may include two or more branches. The first branch and the second branch may be two branches included in the battery module that form a loop current.

[0117] Determining the SOC of the battery cells on at least one of the first branch and the second branch may include at least one of the following:

[0118] When the OCV of the first branch is higher than the OCV of the second branch, and the battery module is in a charging state, at least the SOC of the battery cell on the second branch is determined;

[0119] When the OCV of the first branch is higher than the OCV of the second branch, and the battery is in a discharging state, determining at least the SOC of the battery cell on the first branch;

[0120] The SOCs of all battery cells on the first branch and the second branch are determined respectively.

[0121] The OCV of the aforementioned first branch is: the total OCV of all battery cells in the first branch connected in series and parallel; the OCV of the second branch is: the total OCV of all battery cells in the second branch connected in series and parallel.

[0122] After determining the SOC of the battery cell on at least one branch, an extreme value is determined from the determined SOC according to whether the battery module is currently in a charging state or a discharging state.

[0123] If the battery module is in charging state, an external power source charges the battery module, and if the battery module is in discharging state, the battery module supplies power to the load. The extreme value of SOC includes: a maximum value or a minimum value of SOC.

[0124] If the OCV of the first branch and the second branch are different, when both the first branch and the second branch are closed, mutual discharge between the two branches will occur, thereby generating a circulation current. In an embodiment of the present application, in order to prevent overcharging or over-discharging of individual battery cells caused by the circulation current, the circulating current amount will be estimated in advance. The circulating current amount is: the total amount of charge transferred to form a circulation between the first branch and the second branch. Determining the circulating current amount in S130 may include: predicting the amount of charge transferred from the first branch to the second branch. For example, the specific prediction or estimation of the circulating current amount may include: pre-calculating the amount of charge transferred through the circulation based on the SOC and OCV of the first branch and the second branch, so that the amount of charge transferred when the OCV of the first branch and the second branch is basically the same. In the embodiment of the present disclosure, the prediction or estimation of the circulating current amount here can be achieved through methods such as circulation simulation. In an embodiment of the present application, corresponding protection operations are performed based on the extreme values of the circulating current power and the corresponding SOC. The protection operations include but are not limited to: charge and discharge stop operations and / or discharge stop reminder information output, thereby reducing overcharging or over-discharging of individual battery cells caused by the circulating current.

[0125] In some embodiments, the OCV of the first branch is higher than the OCV of the second branch; the S120 may include:

[0126] When the battery module is in a charging state, determining a maximum SOC value of the battery cell on the second branch;

[0127] When the battery module is in a discharging state, a minimum SOC value of the battery cell on the first branch is determined.

[0128] If the OCV of the first branch is lower than that of the second branch, and if the circuit breakers or other switching devices on both branches are closed at the same time, a circulating current will be formed, discharging from the second branch to the first branch. In this case, if the battery module is in a discharging state when determining the SOC extreme value in S120, the SOC extreme value may be the minimum SOC value on the second branch. If the battery is in a charging state when determining the SOC extreme value in S120, the SOC extreme value at this time is the minimum SOC value on the second branch.

[0129] like Figure 4AAs shown, the S140 may include:

[0130] S141A: When the circulating current and the SOC reach maximum values, determining a first moment when the SOC of the battery cell corresponding to the maximum SOC value reaches a first preset value;

[0131] S142A: At the first moment, stop charging the battery module.

[0132] If the battery module is in a charging state, after charging is completed, a loop current will be formed between the first branch and the second branch, and the second branch will be charged by the first branch. If the SOCs of multiple battery cells on the second branch are different at this time, the battery cell with the highest SOC will continue to be charged by the loop current of the first branch, which may cause overcharging. Therefore, in order to prevent the overcharging of individual battery cells on the second branch, the first moment when the SOC maximum value on the second branch is fully charged is pre-calculated. In this way, charging of the entire battery module can be stopped when the first moment is reached. In this way, after charging is stopped, even if the relays on the first and second branches are not disconnected, a loop current will be formed between the first and second branches, and this loop current will not cause overcharging of the battery cells on the second branch.

[0133] The first preset value can be a threshold for when the corresponding battery cell is fully charged, or a value when a preset charge level is reached. If the first preset value is a threshold for when the battery cell is fully charged, the first preset value can be 100%. For example, the first preset value can be any value between 98% and 100%. Allowing the first preset value to be between 98% and 100% allows for a certain amount of calculation error and battery cell charge estimation error, thereby reducing overcharging of battery cells due to calculation errors.

[0134] In one embodiment, Figure 4B As shown, the S140 may include:

[0135] S141B: When the circulating current and the SOC are at their minimum values, determining a second moment when the battery cell corresponding to the minimum SOC value reaches a second preset value;

[0136] S142B: Execute a protection operation according to the second moment.

[0137] If the battery module is in the state of discharging to an external device, the OCV between the two branches with unstable discharge will be predicted in advance, and the circulating current generated when the high OCV discharges to the low OCV branch and the minimum SOC of the battery cell on the high OCV branch will be predicted in advance. The second moment will be determined in advance, and the protection operation will be performed when or before the second moment is reached, so as to better protect the battery module.

[0138] The performing of the protection operation according to the second moment includes at least one of the following:

[0139] At the second moment, stopping the discharge of the first branch;

[0140] At the second moment, stopping the discharge of the battery module;

[0141] At or before the second moment, a reminder message is output.

[0142] When the battery module is in a discharging state and the OCV of the first branch is higher than that of the second branch, the first branch will discharge into the second branch after the discharge is completed. At this time, considering the circulating discharge from the first branch to the second branch, the time (i.e., the second time) at which the battery cell with the minimum SOC in the first branch will not be over-discharged is determined based on the circulating discharge power of the circulating battery cell and the minimum SOC in the first branch.

[0143] The second preset value may be any pre-set value for preventing over-discharge of a battery cell, for example, 3%, 5%, 8% or 10%.

[0144] Stopping the discharge of the first branch at the second moment includes, but is not limited to, disconnecting a switch such as a circuit breaker on the first branch, thereby stopping the discharge of the first branch. In this way, the battery cells on the first branch can continue to provide external discharge for the battery module.

[0145] If the equipment of the battery module is not in operation, the external discharge of the battery module can be stopped in advance at the second moment. In this way, even if the switches such as relays on the first branch and / or the second branch are not turned on or off, a circulation current is formed between the first branch and the second branch, and the battery cells with the minimum SOC value on the first branch will not be over-discharged due to the circulation current.

[0146] In some embodiments, the reminder information includes:

[0147] Charging reminder information;

[0148] and / or

[0149] Change reminder information.

[0150] By outputting the charging reminder information, the user may charge the battery module before the second moment after seeing it, so that even if there is a circulation between the first branch and the second branch of the battery module, one or more battery cells with a relatively small SOC on the first branch will not be over-discharged.

[0151] The replacement reminder message allows timely replacement of battery cells with significantly reduced charge capacity or severe aging, thereby ensuring the overall power supply performance of the battery module. If the battery module is used in a vehicle, the replacement of rapidly aged battery cells can also ensure the battery module's endurance.

[0152] The determining of the circulating current amount discharged from the first branch to the second branch includes:

[0153] The circulating current amount required for the first branch to discharge to the second branch is determined when the OCV difference between the first branch and the second branch reaches a preset range.

[0154] Specifically, the circulating charge can be determined based on the difference in current OCV between the first branch and the second branch, and the amount of charge discharged from the first branch to the second branch each time a specific OCV difference is reduced. Based on the circulating charge, the SOC that each battery cell on the first branch needs to discharge, as well as the SOC that each battery cell on the second branch will receive, can be determined, thereby enabling over-discharge or over-charge protection of the battery cells in the first or second branch.

[0155] The difference in OCV between the first branch and the second branch is within a preset range, which may be a predetermined empirical value or a laboratory value, for example, 0.1V, 0.5V, 0.8V, etc.

[0156] In some embodiments, the circulating current amount can be determined according to a preconfigured calculation formula, or it can be calculated in an iterative manner. In short, there are many ways to calculate the circulating current amount, and the specific implementation is not limited to the above examples.

[0157] The OCV of the first branch is higher than the OCV of the second branch;

[0158] The determining the circulating current amount required for the first branch to discharge to the second branch when the OCV difference between the first branch and the second branch reaches a preset range includes:

[0159] determining an OCV difference between the first branch and the second branch after each transfer of a preset amount of electricity from the first branch to the second branch;

[0160] When the OCV difference is within the preset range, the circulating power is determined according to the number of times the preset power is transferred from the first branch to the second branch.

[0161] The determining the circulating current amount required for the first branch to discharge to the second branch when the OCV difference between the first branch and the second branch reaches a preset range includes:

[0162] Determining, based on the m+1th SOC difference between the SOCs of the first branch and the SOCs of the second branch after transferring charge m times, the m+1th OCV difference between the first branch and the second branch after transferring charge from the first branch to the second branch by a preset ratio of the m+1th SOC difference; wherein m is 0 or a positive integer;

[0163] When the (m+1)th OCV difference is within the preset range, the sum of the (m+1) times transferred electricity is determined as the circulating current electricity.

[0164] The preset ratio can be 1 / 2 or 1 / 3. By simulating and predicting flow based on the SOC difference, the circulating power can be calculated more accurately with fewer transfers. For example, if the total power in the first transfer is 1 / 2 of the SOC difference between the two branches, the OCVs of the two branches may be rapidly approaching. With a few more simulated transfers, the circulating power can be quickly and accurately calculated.

[0165] The S110 may include: when the SOC of the battery module reaches a third preset value, determining the SOCs of the battery cells in the first branch and the second branch of the battery module.

[0166] The third preset value here may be a threshold for starting to estimate the circulating power between the first branch and the second branch. For example, when the battery module is in a charging state, the third preset value may be 90%, 85%, or 95%, etc. For another example, when the battery module is in a discharging state, the third preset value may be 10%, 15%, or 20%.

[0167] In some embodiments, the third preset value may be predetermined or dynamically determined.

[0168] In an embodiment of the present application, the method further includes:

[0169] The third preset value is determined according to at least one of the charge and discharge state of the battery module, the environmental parameters of the first branch, the environmental parameters of the second branch, the specification parameters of the battery cells on the first branch, and the specification parameters of the battery cells on the second branch.

[0170] The environmental parameters of the first branch and the second branch may include at least a temperature value. The temperature value affects the capacity of the battery cell, so a third preset value suitable for the current battery module can be determined based on the temperature and the current charge and discharge state of the battery.

[0171] In some embodiments, the loop flow calculation can be started when the battery module enters the charging state or the discharging state, or the circulating current quantity can be calculated only when the SOC of the battery module reaches a third preset value after discharge or the SOC of the battery module reaches a third preset value after charging, thereby reducing the amount of calculation.

[0172] In the initial equilibrium state, the terminal voltages of the two branches (i.e., the OCV of the aforementioned branches) are consistent. During the charging and discharging process, the currents between the branches are inconsistent, resulting in a difference in the charge of the two branches. After stopping charging and discharging, due to the inconsistent capacity between the branches (resulting in inconsistent OCV voltages), one branch will charge the other branch (called circulating current).

[0173] If there is a battery cell (i.e., a battery cell) with a low SOC in the discharge branch when circulating current occurs, the battery cell may be over-discharged during the circulating current process. Therefore, it is necessary to estimate in real time whether the single battery cell in the branch will be over-discharged during the static process of stopping discharge at this moment.

[0174] Similarly, it is necessary to determine in real time at the charging end whether charging will be stopped at this moment during the charging process, and whether the battery cell with the highest SOC in the charged branch will be overcharged during the circulation process. The overall charge of branch 1 is lower than that of branch 2, but the charge of cell 1 in branch 1 is higher. When branch 2 is circulating charging branch 1, there is a risk of overcharging cell 1 in branch 1.

[0175] In summary, when there are differences between the two branches due to uneven current flow during the charging and discharging process, after the charging and discharging is completed, the circulating current will cause the single battery cell in the branch to be overcharged or over-discharged.

[0176] like Figure 5 As shown, an embodiment of the present application provides an application device of a battery module, comprising:

[0177] A first determining module 110 is configured to determine the state of charge (SOC) of a battery cell on at least one of a first branch and a second branch of the battery module;

[0178] A second determining module 120 is configured to determine an extreme value of the SOC according to a charge and discharge state of the battery module;

[0179] A third determining module 130 is configured to determine the amount of circulating electricity circulating between the first branch and the second branch;

[0180] The execution module 140 is configured to execute a protection operation according to the extreme values of the circulating current and the SOC.

[0181] The application device of the battery module may be included in the battery module.

[0182] In one embodiment, the first determination module 110 , the second determination module 120 , the third determination module 130 and the execution module 140 may be program modules; after being executed by a processor, the program modules can implement the functions of the above modules.

[0183] In one embodiment, the first determination module 110, the second determination module 120, the third determination module 130 and the execution module 140 may be soft-hard combination modules; the soft-hard combination modules include but are not limited to various programmable arrays; the programmable arrays include but are not limited to: field programmable arrays and / or complex programmable arrays.

[0184] In some other embodiments, the first determination module 110 , the second determination module 120 , the third determination module 130 and the execution module 140 may be pure hardware modules; the pure hardware modules include but are not limited to application-specific integrated circuits.

[0185] In one embodiment, the OCV of the first branch is higher than the OCV of the second branch;

[0186] The second determination module 120 is configured to determine a maximum SOC value of the battery cell on the second branch when the battery module is in a charging state; and to determine a minimum SOC value of the battery cell on the first branch when the battery module is in a discharging state.

[0187] In one embodiment, the execution module 140 is configured to, when the circulating current and the SOC reach their maximum values, determine a first moment when the SOC of the battery cell corresponding to the maximum SOC value reaches a first preset value; and stop charging the battery module at the first moment.

[0188] In one embodiment, the execution module 140 is configured to determine a second moment when the circulating current and the SOC have minimum values and the battery cell corresponding to the minimum SOC value reaches a second preset value; and execute a protection operation according to the second moment.

[0189] In one embodiment, the execution module 140 specifically performs at least one of the following:

[0190] At the second moment, stopping the discharge of the first branch;

[0191] At the second moment, stopping the discharge of the battery module;

[0192] At or before the second moment, a reminder message is output.

[0193] In one embodiment, the reminder information includes:

[0194] Charging reminder information;

[0195] and / or

[0196] Change reminder information.

[0197] In one embodiment, the third determining module 130 is configured to determine the circulating current amount required to be discharged from the first branch to the second branch when the OCV difference between the first branch and the second branch reaches a preset range.

[0198] In one embodiment, the OCV of the first branch is higher than the OCV of the second branch;

[0199] The third determination module 130 is specifically used to determine the OCV difference between the first branch and the second branch after each time the first branch transfers a preset amount of electricity to the second branch; when the OCV difference is within the preset range, the circulating current amount is determined based on the number of times the first branch transfers the preset amount of electricity to the second branch.

[0200] In one embodiment, the third determining module 130 is specifically configured to determine the SOCs of the battery cells in the first branch and the second branch of the battery module when the SOC of the battery module reaches a third preset value.

[0201] In one embodiment, the apparatus further comprises:

[0202] The fourth determining module is configured to determine the third preset value according to at least one of the charge and discharge state of the battery module, the environmental parameters of the first branch, and the environmental parameters of the second branch.

[0203] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0204] The above embodiments are intended only to illustrate the technical solutions of this application and are not intended to limit this application. Those skilled in the art will appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application are intended to be within the scope of protection of this application.

Claims

1. A battery module application method, characterized in that: include: Determining the state of charge (SOC) of a battery cell on at least one of a first branch and a second branch of the battery module according to the charge and discharge state of the battery module; Determining an extreme value of the SOC according to a charge and discharge state of the battery module; Determine a circulating amount of electricity circulating between the first branch and the second branch, where the circulating amount is a total amount of charge transferred by the circulating current between the first branch and the second branch; Performing a protection operation according to the circulating current amount and the extreme value of the SOC to prevent the circulating current from causing overcharge or over-discharge of the single battery; The circulating electricity amount transferred by circulating current is determined according to the SOC and OCV of the first branch and the second branch.

2. The method according to claim 1, characterized in that The OCV of the first branch is higher than the OCV of the second branch; Determining the extreme value of the SOC according to the charge and discharge state of the battery module includes: When the battery module is in a charging state, determining a maximum SOC value of the battery cell on the second branch; When the battery module is in a discharging state, a minimum SOC value of the battery cell on the first branch is determined.

3. The method according to claim 2, characterized in that The performing of a battery protection operation according to the extreme values of the circulating current and the SOC includes: Determining, based on the circulating current and the maximum value of the SOC, a first moment when the SOC of the battery cell corresponding to the maximum value of the SOC reaches a first preset value; At the first moment, charging of the battery module is stopped.

4. The method according to claim 2, characterized in that The performing of a protection operation according to the extreme values of the circulating current and the SOC includes: Determining, based on the circulating current and the minimum value of the SOC, a second moment when the battery cell corresponding to the minimum value of the SOC reaches a second preset value; According to the second moment, a protection operation is performed.

5. The method according to claim 4, characterized in that The performing of the protection operation according to the second moment includes at least one of the following: At the second moment, stopping the discharge of the first branch; At the second moment, stopping the discharge of the battery module; At or before the second moment, a reminder message is output.

6. The method according to claim 5, characterized in that The reminder information includes: Charging reminder information; and / or Change reminder information.

7. The method according to any one of claims 1 to 6, characterized in that The determining of the circulating current amount discharged from the first branch to the second branch includes: The circulating current amount required for the first branch to discharge to the second branch is determined when the OCV difference between the first branch and the second branch reaches a preset range.

8. The method according to claim 7, characterized in that The OCV of the first branch is higher than the OCV of the second branch; The determining the circulating current amount required for the first branch to discharge to the second branch when the OCV difference between the first branch and the second branch reaches a preset range includes: determining an OCV difference between the first branch and the second branch after each transfer of a preset amount of electricity from the first branch to the second branch; When the OCV difference is within the preset range, the circulating power is determined according to the number of times the preset power is transferred from the first branch to the second branch.

9. The method according to any one of claims 1 to 6, characterized in that The determining of the SOC of the battery cells on the first branch and the second branch of the battery module further includes: When the SOC of the battery module reaches a third preset value, the SOCs of the battery cells in the first branch and the second branch of the battery module are determined.

10. The method according to claim 9, characterized in that The method further comprises: The third preset value is determined according to at least one of the charge and discharge state of the battery module, the environmental parameter of the first branch, and the environmental parameter of the second branch.

11. An application device of a battery module, characterized in that: include: a first determining module, configured to determine a state of charge (SOC) of a battery cell on at least one of a first branch and a second branch of the battery module according to a charge and discharge state of the battery module; A second determining module is configured to determine an extreme value of the SOC according to a charge and discharge state of the battery module; a third determining module, configured to determine a circulating amount of electricity circulating between the first branch and the second branch, where the circulating amount is a total amount of charge transferred by the circulating current between the first branch and the second branch; an execution module, configured to execute a protection operation according to the circulating current amount and the extreme value of the SOC, so as to prevent the circulating current from causing overcharging or over-discharging of the single battery; The third determining module is further configured to determine the circulating current amount transferred through the circulating current according to the SOC and OCV of the first branch and the second branch.

12. The device according to claim 11, characterized in that The OCV of the first branch is higher than the OCV of the second branch; The second determination module is used to determine the maximum SOC value of the battery cell on the second branch when the battery module is in a charging state; and to determine the minimum SOC value of the battery cell on the first branch when the battery module is in a discharging state.

13. A power supply module, characterized in that: include: a memory storing computer-executable instructions; A processor, connected to the memory, is configured to implement the application method of the battery module according to any one of claims 1 to 10 by executing the computer-executable instructions.

14. A computer storage medium, characterized in that The computer storage medium contains computer executable instructions, and after the computer executable instructions are executed, the application method of the battery module according to any one of claims 1 to 10 can be implemented.

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