Pre-overcurrent management method and system for a battery pack

Abstract

The application provides a pre-overcurrent management method and system of a battery pack, whether a branch meets a pre-overcurrent opening condition is judged according to branch allowable information and actual branch usage information of the branch of a parallel multi-branch battery pack; if yes, pre-overcurrent calculation is performed according to the branch allowable information of the branch meeting the pre-overcurrent opening condition and the actual branch usage information of each branch, and target branch allowable information of the branch meeting the pre-overcurrent opening condition is obtained; if no, target vehicle allowable power or target vehicle allowable current of the branch not meeting the pre-overcurrent opening condition is calculated according to the vehicle allowable power or the vehicle allowable current of each branch; the vehicle allowable power or the vehicle allowable current of the parallel multi-branch battery pack determined according to the target vehicle allowable power or the target vehicle allowable current of each branch is sent to a vehicle controller of an electric vehicle, so that the vehicle controller charges or discharges according to the vehicle allowable power or the vehicle allowable current of the parallel multi-branch battery pack.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle technology, and more specifically, to a pre-overcurrent management method and system for a battery pack. Background Technology

[0002] Parallel multi-branch battery packs include multiple branches. Due to the inconsistency in the internal resistance of each branch, the actual operating current of each branch varies. Furthermore, as the battery pack ages, the inconsistency in the internal resistance between the branches will also increase, which will further lead to the current of a certain branch in the battery pack exceeding the limit for a long time, thus seriously affecting the safety of battery use.

[0003] To address the aforementioned issues, in existing technologies, when the actual operating current of a branch exceeds the limit, the total current of each branch can be calculated based on its minimum current value, i.e., the vehicle current can be calculated. Then, based on the vehicle current, the allowable current of the battery pack can be reduced to a lower level to prevent overcurrent risks in the branch. Alternatively, hardware and corresponding strategies can be added to each branch to control the current output value of each branch separately, thus solving the overcurrent problem in a branch that may be caused by inconsistencies among the branches from the source.

[0004] However, when the actual current used in a branch exceeds the limit, limiting the allowable current of the entire vehicle can prevent the risk of overcurrent in the branch. However, reducing the allowable current of the battery pack to a low level will severely limit the output of the total current of the battery pack, thus affecting the vehicle's power performance. Furthermore, adding hardware and corresponding control strategies to each branch to control the current output of each branch will increase costs. Summary of the Invention

[0005] In view of this, the present invention provides a pre-overcurrent management method and system for a battery pack, to solve the problem that in the prior art, reducing the allowable current of the battery pack to a low level severely limits the output of the total current of the battery pack, thereby affecting the vehicle's power performance. Furthermore, adding hardware and corresponding control strategies to each branch to control the current output of each branch separately increases costs.

[0006] The first aspect of this application provides a pre-overcurrent management method for a battery pack, the method comprising:

[0007] Real-time acquisition of battery pack allowance information of parallel multi-branch battery packs of electric vehicles; wherein, the battery pack allowance information includes branch allowance information of each branch of the parallel multi-branch battery pack; the branch allowance information includes the vehicle allowance power or vehicle allowance current of the branch.

[0008] For each branch, based on the branch allowable information and the actual branch usage information, it is determined whether the branch meets the pre-overcurrent opening condition; wherein, the actual branch allowable information includes the actual power or actual current used by the branch;

[0009] If the branch meets the pre-overcurrent opening condition, pre-overcurrent calculation is performed based on the branch allowable information of the branch that meets the pre-overcurrent opening condition and the actual branch usage information of each branch to obtain the target branch allowable information of the branch that meets the pre-overcurrent opening condition; wherein, the target branch allowable information includes the target vehicle allowable power or target vehicle allowable current of the branch.

[0010] If the branch does not meet the pre-overcurrent opening condition, calculate the target vehicle allowable power or target vehicle allowable current of the branch that does not meet the pre-overcurrent opening condition based on the vehicle allowable power or vehicle allowable current of each branch.

[0011] Based on the target allowable power or target allowable current of the vehicle for each of the aforementioned branches, the allowable power or allowable current of the parallel multi-branch battery pack is determined, and the allowable power or allowable current of the parallel multi-branch battery pack is sent to the vehicle controller of the electric vehicle, so that the vehicle controller can charge or discharge according to the allowable power or allowable current of the parallel multi-branch battery pack.

[0012] A second aspect of this application provides a pre-overcurrent management system for a battery pack, the system comprising:

[0013] The acquisition unit is used to acquire in real time the battery pack allowable information of the parallel multi-branch battery pack of the electric vehicle; wherein, the battery pack allowable information includes the branch allowable information of each branch of the parallel multi-branch battery pack; the branch allowable information includes the vehicle allowable power or vehicle allowable current of the branch.

[0014] The first judgment unit is used to determine, for each branch, whether the branch meets the pre-overcurrent opening condition based on the branch allowable information and the actual branch usage information; wherein, the actual branch allowable information includes the actual power or actual current used by the branch.

[0015] The first calculation unit is used to perform pre-overcurrent calculation based on the branch allowable information of the branch that meets the pre-overcurrent opening condition and the actual branch usage information of each branch if the branch meets the pre-overcurrent opening condition, so as to obtain the target branch allowable information of the branch that meets the pre-overcurrent opening condition; wherein, the target branch allowable information includes the target vehicle allowable power or the target vehicle allowable current of the branch.

[0016] The second calculation unit is used to calculate the target vehicle allowable power or target vehicle allowable current of the branch that does not meet the pre-overcurrent opening condition, based on the vehicle allowable power or vehicle allowable current of each branch.

[0017] A charging or discharging control unit is used to determine the vehicle allowable power or vehicle allowable current of the parallel multi-branch battery pack based on the target vehicle allowable power or target vehicle allowable current of each of the said branches, and send the vehicle allowable power or vehicle allowable current of the parallel multi-branch battery pack to the vehicle controller of the electric vehicle, so that the vehicle controller can charge or discharge according to the vehicle allowable power or vehicle allowable current of the parallel multi-branch battery pack.

[0018] This application provides a pre-overcurrent management method and system for a battery pack, applied to a Battery Management System (BMS). It acquires battery pack allowance information for a parallel multi-branch battery pack in an electric vehicle. The allowance information includes branch allowance information for each branch of the parallel multi-branch battery pack. The branch allowance information includes the vehicle's allowable power or vehicle's allowable current for that branch. For each branch, based on the branch allowance information and actual branch usage information, it is determined whether the branch meets the pre-overcurrent activation condition. The actual branch allowance information includes the actual power or actual current used by the branch. If the branch meets the pre-overcurrent activation condition, pre-overcurrent calculation is performed based on the branch allowance information of the branch meeting the pre-overcurrent activation condition and the actual branch usage information of each branch to obtain the target branch allowance information for the branch meeting the pre-overcurrent activation condition. The target branch allowance information includes the target vehicle's allowable power or target current used by the branch. The allowable current of the vehicle; if the branch does not meet the pre-overcurrent opening condition, the target allowable power or target allowable current of the branch that does not meet the pre-overcurrent opening condition is calculated based on the allowable power or allowable current of the vehicle for each branch; based on the target allowable power or target allowable current of the vehicle for each branch, the allowable power or allowable current of the parallel multi-branch battery pack is determined, and the allowable power or allowable current of the parallel multi-branch battery pack is sent to the vehicle controller of the electric vehicle, so that the vehicle controller charges or discharges according to the allowable power or allowable current of the parallel multi-branch battery pack. It can be seen that the technical solution provided by this application does not require adjustment of the allowable power of the parallel multi-branch battery pack, thus avoiding limiting the output of the total current of the parallel multi-branch battery pack and avoiding the corresponding power type of the vehicle. At the same time, the technical solution provided by this application does not require additional hardware, thus avoiding additional costs. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 A schematic flowchart illustrating a pre-overcurrent management method for a battery pack provided in an embodiment of this application;

[0021] Figure 2 A flowchart illustrating another pre-overcurrent management method for a battery pack provided in an embodiment of this application;

[0022] Figure 3 This is a schematic diagram of the structure of a pre-overcurrent management system for a battery pack, provided in an embodiment of this application. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] In this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0025] See Figure 1 The diagram illustrates a flowchart of a pre-overcurrent management method for a battery pack according to an embodiment of this application. The pre-overcurrent management method specifically includes the following steps:

[0026] S101: Obtain the battery pack allowable information of the parallel multi-branch battery pack of the electric vehicle; wherein, the battery pack allowable information includes the vehicle allowable power or vehicle allowable current of each branch of the parallel multi-branch battery pack.

[0027] During the specific execution of step S101, after the BMS is powered on and initialized, it can detect in real time whether the current sampled value is stable. When the current sampled value is detected to be stable, that is, after the sampled value is stable, it can collect the environmental information of the current environment of the parallel multi-branch battery pack, and query the battery pack allowance information of the corresponding parallel multi-branch battery pack based on the collected environmental information.

[0028] In some embodiments, after the Battery Management System (BMS) is powered on and initialized, it can detect the voltage fluctuation of multiple parallel battery packs in real time and determine whether the detected voltage fluctuation is less than the voltage fluctuation threshold. If it is less than the threshold, it means that the current sampling error is within the preset range, and the current sampling value can be considered stable. If it is not less than the threshold, it means that the current sampling error exceeds the preset range, and the current sampling value can be considered unstable. In this case, a corresponding reminder message can be issued to remind the user that the current sampling value has a certain error.

[0029] It should be noted that the battery pack allowable information includes the allowable information of each branch of the parallel multi-branch battery pack. The branch allowable information may include the vehicle allowable power or the vehicle allowable current of the branch; the vehicle allowable power may be the vehicle charging allowable power or the vehicle discharging allowable power; the vehicle allowable current may be the vehicle charging allowable current or the vehicle discharging allowable current.

[0030] In some embodiments, after determining that the current sampled value is stable, the BMS can further acquire environmental information about the current environment of the parallel multi-branch battery pack and detect whether the parallel multi-branch battery pack is currently in a discharging or charging state. The environmental information may include at least information such as the temperature of the environment in which the parallel multi-branch battery pack is currently located. If it is currently in a discharging state, the corresponding power meter or ammeter can be queried based on the environmental information to obtain the vehicle's allowable discharge power or allowable discharge current for each branch of the parallel multi-branch battery pack. If it is currently in a charging state, the corresponding power meter and ammeter can be queried based on the environmental information to obtain the vehicle's allowable charging power or allowable charging current for each branch of the parallel multi-branch battery pack.

[0031] S102: For each branch, determine whether the branch meets the pre-overcurrent activation condition based on the branch's allowable information and actual branch usage information; wherein, the actual branch allowable information includes the branch's actual power or actual current usage. If the branch meets the pre-overcurrent activation condition, proceed to step S103; if the branch does not meet the pre-overcurrent activation condition, proceed to step S104.

[0032] During the specific execution of step S102, after power-on initialization, the BMS enters the corresponding operating state. During operation, the BMS can determine whether each branch meets the pre-overcurrent activation condition based on the vehicle's allowable power and the actual power used by each branch, or based on the vehicle's allowable current and the actual current used by each branch. Here, the vehicle's allowable power refers to either the vehicle's charging allowable power or the vehicle's discharging allowable power; correspondingly, the actual current used refers to either the actual charging current or the actual discharging current.

[0033] It should be noted that corresponding pre-overcurrent activation conditions can be preset. Specifically, when multiple battery packs in parallel are in a charging state, the pre-overcurrent activation condition indicates that the difference between the absolute value of the allowable charging power of the whole vehicle and the current actual charging power used by each branch is less than the over-limit threshold of the actual charging power of each branch; or it indicates that the difference between the absolute value of the allowable charging current of the whole vehicle and the current actual charging current used by each branch is less than the over-limit threshold of the actual charging current of each branch.

[0034] When multiple battery packs connected in parallel are in a discharging state, the pre-overcurrent activation condition indicates that the difference between the allowable discharge power of the vehicle and the actual discharge power currently used by each branch is less than the over-limit threshold of the actual discharge power corresponding to each branch; or indicates that the difference between the allowable discharge current of the vehicle and the actual discharge current currently used by each branch is less than the over-limit threshold of the actual discharge current corresponding to each branch.

[0035] As one implementation of this application, the branch allowable information includes the vehicle allowable power of the branch, and the actual branch usage information includes the actual usage power of the branch, which is the actual charging power or the actual discharging power. For each branch, the process of determining whether the branch meets the pre-overcurrent opening condition based on the branch allowable information and the actual branch usage information can be as follows: For each branch, determine whether the vehicle allowable power of the branch is the vehicle charging allowable power or the vehicle discharging allowable power; if the vehicle allowable power is the vehicle charging allowable power, calculate the charging power difference between the absolute value of the vehicle charging allowable power of the branch and the actual charging power used by the branch; determine the charging power difference. If the difference in charging power is less than the actual charging power over-limit threshold of the branch, the branch is determined to meet the pre-overcurrent activation condition; if the difference in charging power is not less than the actual charging power over-limit threshold, the branch is determined not to meet the pre-overcurrent activation condition. If the allowable power of the whole vehicle is the allowable discharge power of the whole vehicle, calculate the discharge power difference between the allowable charging and discharging power of the branch and the actual discharge power used by the branch; determine if the discharge power difference is less than the actual discharge power over-limit threshold of the branch; if the discharge power difference is less than the actual discharge power over-limit threshold, the branch is determined to meet the pre-overcurrent activation condition; if the discharge power difference is not less than the actual discharge power over-limit threshold, the branch is determined not to meet the pre-overcurrent activation condition.

[0036] It should be noted that if the battery pack specifications are the same on each branch, then the actual charging power over-limit threshold is the same for each branch. For each branch, the actual charging power over-limit threshold can be obtained by multiplying the allowable charging power of the whole vehicle on the branch by a first preset ratio. The first preset ratio can be 5%, 10%, etc., and is not limited in this embodiment.

[0037] For example, a parallel multi-branch battery pack includes three branches: branch 1, branch 2, and branch 3; assuming the allowable charging power of branch 1 is obtained as follows: The allowable charging power for the whole vehicle on branch line 2 is And the allowable charging power for the whole vehicle on branch line 3 is The allowable power of the whole vehicle on branch line 1 Multiply by the first preset ratio to obtain the actual charging power over-limit threshold of branch 1. The allowable power of the whole vehicle on branch road 2 Multiply by the first preset ratio to obtain the actual charging power over-limit threshold of branch 2. The allowable power of the whole vehicle on branch road 3 Multiply by the first preset ratio to obtain the actual charging power over-limit threshold of branch 3. Determine the allowable power of the vehicle in branch 1. The absolute value of the actual charging power used by branch 1 Is the difference less than ,Right now If yes, determine that branch 1 meets the pre-overcurrent activation condition; otherwise, determine that branch 1 does not meet the pre-overcurrent activation condition; determine the allowable power of the vehicle in branch 2. The absolute value of the actual charging power used by branch 2 Is the difference less than ,Right now If yes, determine that branch 2 meets the pre-overcurrent activation condition; otherwise, determine that branch 2 does not meet the pre-overcurrent activation condition; determine the allowable power of the vehicle in branch 3. The absolute value of the actual charging power used by branch 3 Is the difference less than ,Right now If yes, determine that branch 3 meets the pre-overcurrent activation condition; otherwise, determine that branch 3 does not meet the pre-overcurrent activation condition.

[0038] It should be noted that if the battery pack specifications are the same on each branch, then the actual discharge power over-limit threshold is the same for each branch. For each branch, the actual discharge power over-limit threshold can be obtained by multiplying the allowable discharge power of the whole vehicle on the branch by the first preset ratio.

[0039] For example, a parallel multi-branch battery pack includes three branches, namely branch 1, branch 2, and branch 3; assuming the allowable discharge power of branch 1 for the entire vehicle is obtained as follows: The allowable discharge power of the whole vehicle on branch 2 is And the allowable discharge power of the whole vehicle in branch 3 is The allowable power of the whole vehicle on branch line 1 Multiply by the first preset ratio to obtain the actual discharge power over-limit threshold of branch 1. The allowable power of the whole vehicle on branch road 2 Multiply by the first preset ratio to obtain the actual discharge power exceeding threshold of branch 2. The allowable power of the whole vehicle on branch road 3 Multiply by the first preset ratio to obtain the actual discharge power over-limit threshold of branch 3. Determine the allowable power of the vehicle in branch 1. The actual discharge power of branch 1 Is the difference less than ,Right now If yes, determine that branch 1 meets the pre-overcurrent activation condition; otherwise, determine that branch 1 does not meet the pre-overcurrent activation condition; determine the allowable power of the vehicle in branch 2. The actual discharge power used in branch 2 Is the difference less than ,Right now If yes, determine that branch 2 meets the pre-overcurrent activation condition; otherwise, determine that branch 2 does not meet the pre-overcurrent activation condition; determine the allowable power of the vehicle in branch 3. The absolute value of the actual discharge power used in branch 3 Is the difference less than ,Right now If yes, determine that branch 3 meets the pre-overcurrent activation condition; otherwise, determine that branch 3 does not meet the pre-overcurrent activation condition.

[0040] As another implementation of this application embodiment, if the branch allowable information includes the vehicle allowable current of the branch, the process of determining whether the branch meets the pre-overcurrent opening condition based on the branch allowable information for each branch can be as follows: For each branch, determine whether the vehicle allowable current of the branch is the vehicle charging allowable current or whether it is the vehicle discharging allowable current; if the vehicle allowable current is the vehicle charging allowable current, calculate the charging current difference between the absolute value of the vehicle charging allowable current of the branch and the actual charging current used by the branch; determine whether the charging current difference is less than the actual charging current over-limit threshold of the branch; if the charging current difference is small... If the actual charging current exceeds the threshold, the branch is determined to meet the pre-overcurrent activation condition; if the charging current difference is not less than the actual charging current exceeding the threshold, the branch is determined not to meet the pre-overcurrent activation condition; if the vehicle's allowable current is the same as the vehicle's allowable discharge current, calculate the discharge current difference between the branch's allowable charging / discharging current and the branch's actual discharge current; determine if the discharge current difference is less than the branch's actual discharge current exceeding the threshold; if the discharge current difference is less than the actual discharge current exceeding the threshold, the branch is determined to meet the pre-overcurrent activation condition; if the discharge current difference is not less than the actual discharge current exceeding the threshold, the branch is determined not to meet the pre-overcurrent activation condition.

[0041] It should be noted that if the battery pack specifications are the same on each branch, then the actual charging current over-limit threshold for each branch is the same. For each branch, the actual charging current over-limit threshold can be obtained by multiplying the allowable charging current of the whole vehicle on the branch by the first preset ratio.

[0042] For example, suppose the allowable charging current for the entire vehicle in branch 1 is obtained as follows: The allowable charging current for the whole vehicle on branch line 2 is And the allowable charging current for the whole vehicle on branch line 3 is ; The allowable current of the whole vehicle in branch 1 Multiply by the first preset ratio to obtain the actual charging current over-limit threshold of branch 1. The allowable current of the whole vehicle in branch 2 will be... Multiply by the first preset ratio to obtain the actual charging current over-limit threshold of branch 2. The allowable current of the whole vehicle in branch 3 will be... Multiply by the first preset ratio to obtain the actual charging current over-limit threshold of branch 3. Determine the allowable current of the entire vehicle in branch 1. The absolute value of the actual charging current used in branch 1 Is the difference less than ,Right now If yes, determine that branch 1 meets the pre-overcurrent opening condition; otherwise, determine that branch 1 does not meet the pre-overcurrent opening condition; determine the vehicle's allowable current for branch 2. The absolute value of the actual charging current used in branch 2 Is the difference less than ,Right now If yes, determine that branch 2 meets the pre-overcurrent opening condition; otherwise, determine that branch 2 does not meet the pre-overcurrent opening condition; determine the vehicle's allowable current for branch 3. The absolute value of the actual charging current used in branch 3 Is the difference less than ,Right now If yes, determine that branch 3 meets the pre-overcurrent activation condition; otherwise, determine that branch 3 does not meet the pre-overcurrent activation condition.

[0043] It should be noted that if the battery pack specifications are the same on each branch, then the actual discharge current over-limit threshold for each branch is the same. For each branch, the actual discharge current over-limit threshold can be obtained by multiplying the allowable discharge current of the whole vehicle on the branch by the first preset ratio.

[0044] For example, a parallel multi-branch battery pack includes three branches: branch 1, branch 2, and branch 3; assuming the allowable discharge current of branch 1 for the entire vehicle is obtained as follows: The allowable discharge current of the whole vehicle in branch 2 is And the allowable discharge current of the whole vehicle in branch 3 is ; The allowable current of the whole vehicle in branch 1 Multiply by the first preset ratio to obtain the actual discharge current exceeding the threshold of branch 1. The allowable current of the whole vehicle in branch 2 will be... Multiply by the first preset ratio to obtain the actual discharge current exceeding the threshold of branch 2. The allowable current of the whole vehicle in branch 3 will be... Multiply by the first preset ratio to obtain the actual discharge current exceeding the threshold of branch 3. Determine the allowable current of the entire vehicle in branch 1. The actual discharge current of branch 1 Is the difference less than ,Right now If yes, determine that branch 1 meets the pre-overcurrent opening condition; otherwise, determine that branch 1 does not meet the pre-overcurrent opening condition; determine the vehicle's allowable current for branch 2. The actual discharge current of branch 2 Is the difference less than ,Right now If yes, determine that branch 2 meets the pre-overcurrent opening condition; otherwise, determine that branch 2 does not meet the pre-overcurrent opening condition; determine the vehicle's allowable current for branch 3. The absolute value of the actual discharge current of branch 3 Is the difference less than ,Right now If yes, determine that branch 3 meets the pre-overcurrent activation condition; otherwise, determine that branch 3 does not meet the pre-overcurrent activation condition.

[0045] S103: Perform pre-overcurrent calculation based on the branch allowance information and actual branch usage information of each branch to obtain the target branch allowance information of the branch that meets the pre-overcurrent opening conditions.

[0046] In the specific execution of step S103, for each branch, if it is determined that the branch meets the pre-overcurrent activation condition, pre-overcurrent calculation can be performed based on the vehicle's allowable power of each branch and the actual power used by the branch that meets the pre-overcurrent activation condition to obtain the target vehicle's allowable power of the branch that meets the pre-overcurrent activation condition; or, pre-overcurrent calculation can be performed based on the vehicle's allowable current of each branch and the actual current used by the branch that meets the pre-overcurrent activation condition to obtain the target vehicle's allowable current of the branch that meets the pre-overcurrent activation condition. Wherein, the allowable information for the target branch is either the target vehicle's allowable power or the target vehicle's allowable current; the target vehicle's allowable power is either the target vehicle's allowable charging power or the target vehicle's allowable discharging power; and the target vehicle's allowable current is either the target vehicle's allowable charging current or the target vehicle's allowable discharging current.

[0047] As an embodiment of this application, the process of performing pre-overcurrent calculation based on the branch allowable information and actual branch usage information to obtain the target branch allowable information can be as follows: Calculate the vehicle allowable power and the power quotient of the actual power used by the branch that meets the pre-overcurrent opening condition; wherein, the vehicle allowable power is the vehicle charging allowable power or the vehicle discharging allowable power, and the actual power used is the actual charging power or the actual discharging power used; calculate the target vehicle allowable power of the branch that meets the pre-overcurrent opening condition based on the vehicle allowable power of the branch that meets the pre-overcurrent opening condition, the actual power used by each other branch, and the power quotient; wherein, the other branches are branches other than the branches with the target vehicle allowable power, and the target vehicle allowable power is the target vehicle charging allowable power or the target vehicle discharging allowable power.

[0048] In some embodiments, the allowable vehicle charging power of the branch that meets the pre-overcurrent opening condition can be calculated as the power quotient of its actual charging power, and the product of the actual charging power and the power quotient of the other branches can be calculated. Finally, the allowable vehicle charging power of the branch that meets the pre-overcurrent opening condition and the product of the actual charging power and the power quotient of each other branch are summed to obtain the target allowable vehicle charging power of the branch that meets the pre-overcurrent opening condition.

[0049] For example, a parallel multi-branch battery pack includes three branches, namely branch 1, branch 2 and branch 3. Assuming that branch 1 meets the pre-overcurrent opening condition, the method for calculating the target vehicle charging power of branch 1 can be found in formula (1):

[0050] (1)

[0051] Assuming that branch 2 meets the pre-overcurrent opening condition, the method for calculating the target vehicle charging power of branch 1 can be found in formula (2):

[0052] (2)

[0053] Assuming that branch 3 meets the pre-overcurrent opening condition, the method for calculating the target vehicle charging power of branch 3 can be found in formula (2):

[0054] (3)

[0055] In other embodiments, the allowable vehicle discharge power of the branch that meets the pre-overcurrent opening condition can be calculated as the power quotient of its actual discharge power, and the product of the actual discharge power and the power quotient of the other branches can be calculated. Finally, the allowable vehicle discharge power of the branch that meets the pre-overcurrent opening condition and the product of the actual discharge power and the power quotient of each other branch are summed to obtain the target allowable vehicle discharge power of the branch that meets the pre-overcurrent opening condition.

[0056] For example, a parallel multi-branch battery pack includes three branches, namely branch 1, branch 2 and branch 3. Assuming that branch 1 meets the pre-overcurrent opening condition, the method for calculating the target vehicle discharge power of branch 1 can be found in formula (4):

[0057] (4)

[0058] Assuming that branch 2 meets the pre-overcurrent opening condition, the method for calculating the target vehicle discharge power of branch 1 can be found in formula (5):

[0059] (5)

[0060] Assuming that branch 3 meets the pre-overcurrent opening condition, the method for calculating the target vehicle discharge power of branch 3 can be found in formula (6):

[0061] (6)

[0062] As another implementation provided in this application embodiment, the process of performing pre-overcurrent calculation based on the branch allowable information and actual branch usage information to obtain the target branch allowable information can be as follows: Calculate the vehicle allowable current and its actual usage current quotient of the branch that meets the pre-overcurrent opening condition; wherein, the vehicle allowable current is the vehicle charging allowable current or the vehicle discharging allowable current, and the actual usage current is the actual charging current or the actual discharging current; calculate the target vehicle allowable current of the branch that meets the pre-overcurrent opening condition based on the vehicle allowable current of the branch that meets the pre-overcurrent opening condition, the actual usage current of each other branch, and the current quotient; wherein, the other branches are branches other than the currently calculated target vehicle allowable current, and the target vehicle allowable current is the target vehicle charging allowable current or the target vehicle discharging allowable current.

[0063] In some embodiments, the allowable vehicle charging current of the branch that meets the pre-overcurrent opening condition can be calculated as the current quotient of its actual charging current, and the product of the actual charging current and the current quotient of the other branches can be calculated. Finally, the allowable vehicle charging current of the branch that meets the pre-overcurrent opening condition and the product of the actual charging current and the current quotient of each other branch are summed to obtain the target allowable vehicle charging current of the branch that meets the pre-overcurrent opening condition.

[0064] For example, a parallel multi-branch battery pack includes three branches, namely branch 1, branch 2 and branch 3. Assuming that branch 1 meets the pre-overcurrent opening condition, the method for calculating the target vehicle charging current of branch 1 can be found in formula (7):

[0065] (7)

[0066] Assuming that branch 2 meets the pre-overcurrent opening condition, the method for calculating the target vehicle charging current of branch 1 can be found in formula (8):

[0067] (8)

[0068] Assuming that branch 3 meets the pre-overcurrent opening condition, the method for calculating the target vehicle charging current of branch 3 can be found in formula (9):

[0069] (9)

[0070] In other embodiments, the allowable vehicle discharge current of the branch that meets the pre-overcurrent opening condition can be calculated as the current quotient of its actual discharge current, and the product of the actual discharge current and the current quotient of the other branches can be calculated. Finally, the allowable vehicle discharge current of the branch that meets the pre-overcurrent opening condition and the product of the actual discharge current and the current quotient of each other branch are summed to obtain the target allowable vehicle discharge current of the branch that meets the pre-overcurrent opening condition.

[0071] For example, a parallel multi-branch battery pack includes three branches, namely branch 1, branch 2 and branch 3. Assuming that branch 1 meets the pre-overcurrent opening condition, the method for calculating the target vehicle discharge current of branch 1 can be found in formula (10):

[0072] (10)

[0073] Assuming that branch 2 meets the pre-overcurrent opening condition, the method for calculating the target vehicle discharge current of branch 1 can be found in formula (11):

[0074] (11)

[0075] Assuming that branch 3 meets the pre-overcurrent opening condition, the method for calculating the target vehicle discharge current of branch 3 can be found in formula (12):

[0076] (12)

[0077] S104: Based on the allowable power or allowable current of the vehicle in each branch, calculate the target allowable power or target allowable current of the vehicle in the branch that does not meet the pre-overcurrent opening condition.

[0078] In the specific execution of step S104, for each branch, if it is determined that the branch does not meet the pre-overcurrent opening condition, the allowable vehicle power or allowable vehicle current of each branch can be summed to obtain the target allowable vehicle power or target allowable vehicle current of the branch that does not meet the pre-overcurrent opening condition. Here, the allowable vehicle power can be the allowable vehicle charging power or the allowable vehicle discharging power, the allowable vehicle current can be the allowable vehicle charging current or the allowable vehicle discharging current, the target allowable vehicle power can be the target allowable vehicle charging power or the target allowable vehicle discharging power, and the target allowable vehicle current can be the target allowable vehicle charging current or the target allowable vehicle discharging current.

[0079] It should be noted that each branch includes branches that meet the pre-overcurrent opening conditions and branches that do not meet the pre-overcurrent opening conditions.

[0080] For example, a parallel multi-branch battery pack includes three branches, namely branch 1, branch 2, and branch 3. Assuming that branch i does not meet the pre-overcurrent activation condition, the method for calculating the target vehicle charging power of branch i can be found in formula (13), where i can be 1, 2, or 3:

[0081] (13)

[0082] Assuming that branch i does not meet the pre-overcurrent opening condition, the method for calculating the target vehicle discharge power of branch i can be found in formula (14):

[0083] (14)

[0084] Assuming that branch i does not meet the pre-overcurrent activation condition, the method for calculating the target vehicle charging current of branch i can be found in formula (15):

[0085] (15)

[0086] Assuming that branch i does not meet the pre-overcurrent opening condition, the method for calculating the target vehicle discharge current of branch i can be found in formula (16):

[0087] (16)

[0088] S105: Based on the target allowable power or target allowable current of the vehicle for each branch, determine the allowable power or allowable current of the battery pack connected in parallel, and send the allowable power or allowable current of the battery pack connected in parallel to the vehicle controller of the electric vehicle, so that the vehicle controller can charge or discharge according to the allowable power or allowable current of the battery pack connected in parallel.

[0089] In the specific execution of step S105, after obtaining the target vehicle allowable power or target vehicle allowable current for each branch of the parallel multi-branch battery pack, the minimum value among the target vehicle allowable power or target vehicle allowable current of each branch can be determined as the vehicle allowable power or vehicle allowable current of the parallel multi-branch battery pack. The vehicle allowable power or vehicle allowable current of the parallel multi-branch battery pack is then sent to the vehicle controller of the electric vehicle, so that the vehicle controller can charge or discharge according to the vehicle allowable power or vehicle allowable current of the parallel multi-branch battery pack.

[0090] It should be noted that when the parallel multi-branch battery pack is in a charging state, the vehicle's allowable power or allowable current for the parallel multi-branch battery pack is the vehicle's allowable charging power or allowable charging current. In this case, the vehicle controller can control the parallel multi-branch battery pack to charge based on the received vehicle's allowable charging power or allowable charging current. When the parallel multi-branch battery pack is in a discharging state, the vehicle's allowable power or allowable current for the parallel multi-branch battery pack is the vehicle's allowable discharging power or allowable discharging current. In this case, the vehicle controller can control the parallel multi-branch battery pack to discharge based on the received vehicle's allowable discharging power or allowable discharging current.

[0091] This application discloses a pre-overcurrent management method for a battery pack, applied to a Battery Management System (BMS). The method involves acquiring battery pack allowance information for a parallel multi-branch battery pack in an electric vehicle. This allowance information includes branch allowance information for each branch of the parallel multi-branch battery pack, and the branch allowance information includes the branch's allowable vehicle power or allowable vehicle current. For each branch, based on the branch allowance information and actual branch usage information, it is determined whether the branch meets the pre-overcurrent activation conditions. The actual branch allowance information includes the branch's actual operating power or actual operating current. If the branch meets the pre-overcurrent activation conditions, pre-overcurrent calculation is performed based on the branch allowance information of the branch meeting the pre-overcurrent activation conditions and the actual branch usage information of each branch to obtain the target branch allowance information for the branch meeting the pre-overcurrent activation conditions. The target branch allowance information includes the branch's target allowable vehicle power or target allowable vehicle current. If a branch does not meet the pre-overcurrent opening condition, the target vehicle allowable power or target vehicle allowable current of the branch that does not meet the pre-overcurrent opening condition is calculated based on the vehicle allowable power or vehicle allowable current of each branch. Based on the target vehicle allowable power or target vehicle allowable current of each branch, the vehicle allowable power or vehicle allowable current of the parallel multi-branch battery pack is determined, and the vehicle allowable power or vehicle allowable current of the parallel multi-branch battery pack is sent to the vehicle controller of the electric vehicle. The vehicle controller then charges or discharges the battery pack according to the vehicle allowable power or vehicle allowable current of the parallel multi-branch battery pack. Therefore, the technical solution provided in this application does not require adjustment of the vehicle allowable power of the parallel multi-branch battery pack, thus avoiding limiting the total current output of the parallel multi-branch battery pack and avoiding the corresponding power type of the vehicle. At the same time, the technical solution provided in this application does not require additional hardware, thus avoiding additional costs.

[0092] Furthermore, in this embodiment of the application, in order to prevent frequent activation of the corresponding pre-overcurrent calculation due to fluctuations in the actual power usage of the branch, for a branch that meets the pre-overcurrent activation calculation, it can be detected whether the branch meets the pre-overcurrent deactivation condition. If it is determined that the branch meets the pre-overcurrent deactivation condition, the pre-overcurrent calculation is terminated, and the BMS is powered down, thereby avoiding frequent activation of the corresponding overcurrent calculation. Figure 2 As shown, the specific steps include:

[0093] S201: Obtain the battery pack allowable information of the parallel multi-branch battery pack of the electric vehicle; wherein, the battery pack allowable information includes the vehicle allowable power or vehicle allowable current of each branch of the parallel multi-branch battery pack.

[0094] S202: For each branch, determine whether the branch meets the pre-overcurrent activation condition based on the branch's allowable information and actual branch usage information; wherein, the actual branch allowable information includes the branch's actual power or actual current usage. If the branch meets the pre-overcurrent activation condition, proceed to step S203; if the branch does not meet the pre-overcurrent activation condition, proceed to step S204.

[0095] S203: Perform pre-overcurrent calculation based on the branch permission information and actual branch usage information of each branch to obtain the target branch permission information of the branch that meets the pre-overcurrent opening conditions.

[0096] S204: Based on the allowable power or allowable current of the vehicle in each branch, calculate the target allowable power or target allowable current of the vehicle in the branch that does not meet the pre-overcurrent opening condition.

[0097] S205: Based on the target allowable power or target allowable current of the vehicle for each branch, determine the allowable power or allowable current of the battery pack connected in parallel, and send the allowable power or allowable current of the battery pack connected in parallel to the vehicle controller of the electric vehicle, so that the vehicle controller can charge or discharge according to the allowable power or allowable current of the battery pack connected in parallel.

[0098] In the specific execution of steps S201-S205, the specific execution and implementation processes of steps S201-S205 are the same as those of steps S101-S105, which can be found in [reference needed]. Figure 1 The corresponding steps are not described in detail in this embodiment of the application.

[0099] S206: Re-detect the branch permission information and actual branch usage information of each branch that meets the pre-overcurrent opening condition, and based on the re-detected branch permission information and actual branch usage information of each branch that meets the pre-overcurrent opening condition, determine whether there is a branch that meets the pre-overcurrent closing condition among the branches that meet the pre-overcurrent opening condition. If not, return to step S201; if so, proceed to step S207.

[0100] During the specific execution of step S206, for each branch that meets the pre-overcurrent opening condition, i.e., for each branch that is currently performing pre-overcurrent calculation, the branch allowable information and actual branch usage information of the branch that meets the pre-overcurrent opening condition can be re-detected. Based on the re-detected allowable vehicle power and actual usage power of the branch that meets the pre-overcurrent opening condition, it is determined whether the branch that meets the pre-overcurrent opening condition meets the pre-overcurrent closing condition. Alternatively, based on the re-detected allowable vehicle current and actual usage current of the branch that meets the pre-overcurrent opening condition, it is determined whether the branch that meets the pre-overcurrent opening condition meets the pre-overcurrent closing condition. If there is no branch that meets the pre-overcurrent closing condition among the branches that meet the pre-overcurrent opening condition, the execution returns to step S201. If there is a branch that meets the pre-overcurrent closing condition among the branches that meet the pre-overcurrent opening condition, step S207 is executed.

[0101] It should be noted that corresponding pre-overcurrent shutdown conditions can be preset. Specifically, when multiple parallel battery packs are in a charging state, the pre-overcurrent shutdown condition indicates that the difference between the absolute value of the vehicle's allowable charging power and the current actual charging power used by the branch that meets the pre-overcurrent opening condition is less than the actual charging power hysteresis threshold corresponding to the branch; or it indicates that the difference between the absolute value of the vehicle's allowable charging current and the current actual charging current used by the branch that meets the pre-overcurrent opening condition is less than the actual charging current hysteresis threshold corresponding to the branch.

[0102] When multiple battery packs connected in parallel are in a discharging state, the pre-overcurrent shutdown condition indicates that the difference between the allowable vehicle discharge power and the current actual discharge power of the branch that meets the pre-overcurrent opening condition is less than the actual discharge power hysteresis threshold corresponding to the branch; or it indicates that the difference between the allowable vehicle discharge current and the current actual discharge current of the branch that meets the pre-overcurrent opening condition is less than the actual discharge current hysteresis threshold corresponding to the branch.

[0103] As one implementation of this application, for each branch that meets the pre-overcurrent activation condition, it is determined whether the vehicle's allowable power for the re-detected branch that meets the pre-overcurrent activation condition is the vehicle's allowable charging power or the vehicle's allowable discharging power; if the vehicle's allowable power for the re-detected branch that meets the pre-overcurrent activation condition is the vehicle's allowable charging power, the charging power difference between the absolute value of the vehicle's allowable power for the re-detected branch that meets the pre-overcurrent activation condition and its actual charging power is calculated; it is determined whether the calculated charging power difference is less than the actual charging power hysteresis threshold of the branch that meets the pre-overcurrent activation condition; if it is less, it is determined that the pre-overcurrent activation condition is met. If a branch meets the pre-overcurrent turn-off condition, and if it is not less than 1, then the branch that meets the pre-overcurrent turn-on condition does not meet the pre-overcurrent turn-off condition. If the allowable power of the vehicle for the re-detected branch that meets the pre-overcurrent turn-on condition is the allowable discharge power of the vehicle, calculate the difference between the allowable charge / discharge power of the re-detected branch that meets the pre-overcurrent turn-on condition and its actual discharge power. Determine whether the calculated discharge power difference is less than the actual discharge power hysteresis threshold of the branch that meets the pre-overcurrent turn-on condition. If it is less than 1, then the branch that meets the pre-overcurrent turn-on condition meets the pre-overcurrent turn-off condition. If it is not less than 1, then the branch that meets the pre-overcurrent turn-on condition does not meet the pre-overcurrent turn-off condition.

[0104] It should be noted that if the battery pack specifications are the same on each branch, then the actual charging power hysteresis threshold corresponding to each branch is the same. For each branch, the actual charging power hysteresis threshold can be obtained by multiplying the allowable charging power of the whole vehicle on the branch by a second preset ratio. The second preset ratio can be 10%, 15%, etc., and the first preset ratio is less than the second preset ratio. This embodiment of the application does not limit this.

[0105] For example, a parallel multi-branch battery pack includes three branches: branch 1, branch 2, and branch 3; assuming the allowable charging power of the vehicle for branch 1, which meets the pre-overcurrent activation condition, is... The allowable charging power of the whole vehicle in branch 2, which meets the pre-overcurrent opening condition after retesting, is: And the allowable charging power of the whole vehicle in branch 3, which meets the pre-overcurrent opening condition and is retested, is The allowable power of the vehicle in branch 1 that meets the pre-overcurrent activation conditions will be re-tested. Multiply by the second preset ratio to obtain the actual charging power hysteresis threshold of branch 1 that satisfies the pre-overcurrent activation condition. The allowable power of the vehicle in branch 2 that meets the pre-overcurrent opening conditions will be re-tested. Multiplying by the second preset ratio yields the actual charging power hysteresis threshold of branch 2 that satisfies the pre-overcurrent activation condition. The allowable power of the vehicle in branch 3 that meets the pre-overcurrent opening conditions will be re-tested. Multiplying by the second preset ratio yields the actual charging power hysteresis threshold of branch 3 that satisfies the pre-overcurrent activation condition. ;judge The absolute value of the actual charging power used by branch 1 that meets the pre-overcurrent opening condition. Is the difference less than ,Right now If yes, determine that branch 1, which meets the pre-overcurrent opening condition, also meets the pre-overcurrent closing condition; otherwise, determine that branch 1, which meets the pre-overcurrent opening condition, does not meet the pre-overcurrent closing condition. The absolute value of the actual charging power used by branch 2 that meets the pre-overcurrent opening condition. Is the difference less than ,Right now If yes, determine that branch 2, which meets the pre-overcurrent opening condition, also meets the pre-overcurrent closing condition; otherwise, determine that branch 2, which meets the pre-overcurrent opening condition, does not meet the pre-overcurrent closing condition. The absolute value of the actual charging power used by branch 3 that meets the pre-overcurrent opening condition. Is the difference less than ,Right now If yes, then the branch 3 that meets the pre-overcurrent opening condition meets the pre-overcurrent closing condition; otherwise, the branch 3 that meets the pre-overcurrent opening condition does not meet the pre-overcurrent closing condition.

[0106] It should be noted that if the battery pack specifications are the same on each branch, then the actual discharge power hysteresis threshold corresponding to each branch is the same; for each branch, the actual discharge power hysteresis threshold of the branch can be obtained by multiplying the allowable discharge power of the whole vehicle of the branch by the second preset ratio.

[0107] For example, a parallel multi-branch battery pack includes three branches: branch 1, branch 2, and branch 3; assuming the allowable vehicle discharge power of branch 1, which meets the pre-overcurrent activation condition after re-detection, is... The allowable vehicle discharge power of branch 2, which meets the pre-overcurrent opening condition, is retested. And the allowable vehicle discharge power of branch 3, which meets the pre-overcurrent opening condition and is retested, is The allowable power of the vehicle in branch 1 that meets the pre-overcurrent activation conditions will be re-tested. Multiplying by the second preset ratio yields the actual discharge power hysteresis threshold of branch 1 that satisfies the pre-overcurrent activation condition. The allowable power of the vehicle in branch 2 that meets the pre-overcurrent opening conditions will be re-tested. Multiplying by the second preset ratio yields the actual discharge power hysteresis threshold of branch 2 that satisfies the pre-overcurrent opening condition. The allowable power of the vehicle in branch 3 that meets the pre-overcurrent opening conditions will be re-tested. Multiplying by the second preset ratio yields the actual discharge power hysteresis threshold of branch 3 that satisfies the pre-overcurrent activation condition. ;judge The actual discharge power of branch 1 that meets the pre-overcurrent opening condition Is the difference less than ,Right now If yes, determine that branch 1, which meets the pre-overcurrent opening condition, also meets the pre-overcurrent closing condition; otherwise, determine that branch 1, which meets the pre-overcurrent opening condition, does not meet the pre-overcurrent closing condition. The actual discharge power of branch 2 that meets the pre-overcurrent opening condition Is the difference less than ,Right now If yes, determine that branch 2, which meets the pre-overcurrent opening condition, also meets the pre-overcurrent closing condition; otherwise, determine that branch 2, which meets the pre-overcurrent opening condition, does not meet the pre-overcurrent closing condition. The actual discharge power of branch 3 that meets the pre-overcurrent opening condition Is the difference less than ,Right now If yes, then the branch 3 that meets the pre-overcurrent opening condition meets the pre-overcurrent closing condition; otherwise, the branch 3 that meets the pre-overcurrent opening condition does not meet the pre-overcurrent closing condition.

[0108] As another implementation of this application embodiment, for each branch that meets the pre-overcurrent activation condition, it is determined whether the vehicle's allowable current for the re-detected branch that meets the pre-overcurrent activation condition is the vehicle's allowable charging current or the vehicle's allowable discharging current; if the vehicle's allowable current for the re-detected branch that meets the pre-overcurrent activation condition is the vehicle's allowable charging current, the charging current difference between the absolute value of the vehicle's allowable current for the re-detected branch that meets the pre-overcurrent activation condition and its actual charging current is calculated; it is determined whether the calculated charging current difference is less than the actual charging current hysteresis threshold of the branch that meets the pre-overcurrent activation condition; if it is less, it is determined that the pre-overcurrent activation condition is met. If a branch meets the pre-overcurrent shutdown condition, and if it is not less than 1 / 3, then the branch that meets the pre-overcurrent opening condition does not meet the pre-overcurrent shutdown condition. If the vehicle allowable current of the re-detected branch that meets the pre-overcurrent opening condition is the vehicle discharge allowable current, calculate the difference between the vehicle charge / discharge allowable current and its actual discharge current of the re-detected branch that meets the pre-overcurrent opening condition. Determine whether the recalculated discharge current difference is less than the actual discharge current hysteresis threshold of the branch that meets the pre-overcurrent opening condition. If it is less than 1 / 3, then the branch that meets the pre-overcurrent opening condition meets the pre-overcurrent shutdown condition. If it is not less than 1 / 3, then the branch that meets the pre-overcurrent opening condition does not meet the pre-overcurrent shutdown condition.

[0109] It should be noted that if the battery pack specifications are the same on each branch, then the actual charging current hysteresis threshold for each branch is the same. For each branch, the actual charging current hysteresis threshold can be obtained by multiplying the allowable charging current of the whole vehicle on the branch by the second preset ratio.

[0110] For example, a parallel multi-branch battery pack includes three branches: branch 1, branch 2, and branch 3; assuming the allowable charging current of branch 1, which meets the pre-overcurrent activation condition, is... The allowable charging current for the entire vehicle in branch 2, which meets the pre-overcurrent opening condition after retesting, is: And the allowable charging current of the whole vehicle for branch 3, which meets the pre-overcurrent opening condition and is retested, is The allowable vehicle current of branch 1 that meets the pre-overcurrent activation condition will be re-tested. Multiplying by the second preset ratio yields the actual charging current hysteresis threshold of branch 1 that satisfies the pre-overcurrent activation condition. The allowable vehicle current of branch 2 that meets the pre-overcurrent activation condition will be re-tested. Multiplying by the second preset ratio yields the actual charging current hysteresis threshold of branch 2 that satisfies the pre-overcurrent activation condition. The allowable vehicle current of branch 3 that meets the pre-overcurrent opening condition will be re-tested. Multiplying by the second preset ratio yields the actual charging current hysteresis threshold of branch 3 that satisfies the pre-overcurrent activation condition. ;judge The absolute value of the actual operating charging current of branch 1 that meets the pre-overcurrent opening condition Is the difference less than ,Right now If yes, determine that branch 1, which meets the pre-overcurrent opening condition, also meets the pre-overcurrent closing condition; otherwise, determine that branch 1, which meets the pre-overcurrent opening condition, does not meet the pre-overcurrent closing condition. The absolute value of the actual operating charging current of branch 2 that meets the pre-overcurrent opening condition Is the difference less than ,Right now If yes, determine that branch 2, which meets the pre-overcurrent opening condition, also meets the pre-overcurrent closing condition; otherwise, determine that branch 2, which meets the pre-overcurrent opening condition, does not meet the pre-overcurrent closing condition. The absolute value of the actual operating charging current of branch 3 that meets the pre-overcurrent opening condition. Is the difference less than ,Right now If yes, then the branch 3 that meets the pre-overcurrent opening condition meets the pre-overcurrent closing condition; otherwise, the branch 3 that meets the pre-overcurrent opening condition does not meet the pre-overcurrent closing condition.

[0111] It should be noted that if the battery pack specifications are the same on each branch, then the actual discharge current hysteresis threshold for each branch is the same. For each branch, the actual discharge current hysteresis threshold can be obtained by multiplying the allowable discharge current of the whole vehicle on the branch by the second preset ratio.

[0112] For example, a parallel multi-branch battery pack includes three branches: branch 1, branch 2, and branch 3; assuming the allowable discharge current of branch 1, which meets the pre-overcurrent activation condition, is... The allowable discharge current of the whole vehicle for branch 2, which meets the pre-overcurrent opening condition, is retested. And the allowable discharge current of the whole vehicle for branch 3, which meets the pre-overcurrent opening condition and is retested, is The allowable vehicle current of branch 1 that meets the pre-overcurrent activation condition will be re-tested. Multiplying by the second preset ratio yields the actual discharge current hysteresis threshold of branch 1 that satisfies the pre-overcurrent opening condition. The allowable vehicle current of branch 2 that meets the pre-overcurrent activation condition will be re-tested. Multiplying by the second preset ratio yields the actual discharge current hysteresis threshold of branch 2 that satisfies the pre-overcurrent opening condition. The allowable vehicle current of branch 3 that meets the pre-overcurrent opening condition will be re-tested. Multiplying by the second preset ratio yields the actual discharge current hysteresis threshold of branch 3 that satisfies the pre-overcurrent opening condition. ;judge The actual operating discharge current of branch 1 that meets the pre-overcurrent opening condition Is the difference less than ,Right now If yes, determine that branch 1, which meets the pre-overcurrent opening condition, also meets the pre-overcurrent closing condition; otherwise, determine that branch 1, which meets the pre-overcurrent opening condition, does not meet the pre-overcurrent closing condition. The actual operating discharge current of branch 2 that meets the pre-overcurrent opening condition Is the difference less than ,Right now If yes, determine that branch 2, which meets the pre-overcurrent opening condition, also meets the pre-overcurrent closing condition; otherwise, determine that branch 2, which meets the pre-overcurrent opening condition, does not meet the pre-overcurrent closing condition. The actual discharge current of branch 3 that meets the pre-overcurrent opening condition Is the difference less than ,Right now If yes, then the branch 3 that meets the pre-overcurrent opening condition meets the pre-overcurrent closing condition; otherwise, the branch 3 that meets the pre-overcurrent opening condition does not meet the pre-overcurrent closing condition.

[0113] S207: Update the vehicle's allowable power or allowable current of the parallel multi-branch battery pack based on the re-detected branch allowable information, and send the updated vehicle allowable power or allowable current of the parallel multi-branch battery pack to the vehicle controller of the electric vehicle, so that the vehicle controller can charge or discharge according to the updated vehicle allowable power or allowable current of the parallel multi-branch battery pack.

[0114] In the specific execution of step S207, if it is determined that there are branches that meet the pre-overcurrent opening conditions and meet the pre-overcurrent closing conditions, the vehicle's allowable power or vehicle's allowable current of each re-detected branch can be summed to obtain the vehicle's allowable power or vehicle's allowable current of the parallel multi-branch battery pack. The re-obtained vehicle's allowable power or vehicle's allowable current of the parallel multi-branch battery pack is then sent to the vehicle controller of the electric vehicle, so that the vehicle controller can charge or discharge according to the new vehicle's allowable power or vehicle's allowable current of the parallel multi-branch battery pack.

[0115] For example, a parallel multi-branch battery pack includes three branches, namely branch 1, branch 2 and branch 3. Assuming that branch i meets the pre-overcurrent opening condition, the method for recalculating the vehicle charging power of the parallel multi-branch battery pack can be found in formula (17), where i can be 1, 2 or 3:

[0116] (17)

[0117] In formula (17), For the recalculated vehicle charging power of the parallel multi-branch battery pack, The vehicle charging power of branch 1 was retested. The vehicle charging power of branch 2 was retested. The vehicle charging power of branch 3 was retested.

[0118] If the pre-overcurrent start-up condition is not met by branch i, the method for recalculating the vehicle discharge power of the parallel multi-branch battery pack can be found in formula (18):

[0119] (18)

[0120] In formula (18), For the recalculated vehicle discharge power of the parallel multi-branch battery pack, To retest the vehicle discharge power of branch 1, To retest the vehicle discharge power of branch 2, The vehicle discharge power of branch 3 was retested.

[0121] If the pre-overcurrent activation condition is not met by branch i, the method for recalculating the vehicle charging current of the parallel multi-branch battery pack can be found in formula (19):

[0122] (19)

[0123] In formula (19), For the recalculated vehicle charging current of the parallel multi-branch battery pack, The vehicle charging current of branch 1 is being retested. The vehicle charging current of branch 2 is being retested. The vehicle charging current for branch 3, which is being retested.

[0124] If the pre-overcurrent start condition is not met by branch i, the method for recalculating the vehicle discharge current of the parallel multi-branch battery pack can be found in formula (20):

[0125] (20)

[0126] In formula (20), For the recalculated vehicle discharge current of the parallel multi-branch battery pack, The vehicle discharge current of branch 1 is being re-tested. The vehicle discharge current of branch 2 was re-tested. The vehicle discharge current of branch 3 is being retested.

[0127] In this embodiment of the application, after obtaining the new allowable power or allowable current of the parallel multi-branch battery pack, the redefined allowable power or allowable current of the parallel multi-branch battery pack is sent to the vehicle controller of the electric vehicle, so that the vehicle controller can charge or discharge according to the redefined allowable power or allowable current of the parallel multi-branch battery pack.

[0128] S208: Stop the pre-overcurrent calculation for branches that meet both the pre-overcurrent opening and pre-overcurrent closing conditions, and when the pre-overcurrent calculation for branches that meet both the pre-overcurrent opening and pre-overcurrent closing conditions is successfully stopped after a preset time period, control the BMS to power down.

[0129] During the specific execution of step S208, when the vehicle controller is charging or discharging based on the updated allowable power or allowable current of the parallel multi-branch battery pack, it can stop the pre-overcurrent calculation for branches that meet the pre-overcurrent opening and closing conditions, and record the time when the re-determined allowable power or allowable current of the parallel multi-branch battery pack is sent to the vehicle controller of the electric vehicle. It also monitors the BMS time in real time from the start of sending the re-determined allowable power or allowable current of the parallel multi-branch battery pack to the vehicle controller of the electric vehicle. When the timed time reaches the preset time period, it determines whether the pre-overcurrent calculation for branches that meet the pre-overcurrent opening conditions has been successfully stopped. If yes, it controls the BMS to power down; if no, it can issue the corresponding power control signal and control the BMS to power down.

[0130] It should be noted that if the pre-overcurrent calculation for a branch that meets the pre-overcurrent activation condition is not successfully stopped, the BMS can issue a corresponding power control signal and control the BMS to shut down the high voltage.

[0131] Based on the battery pack pre-overcurrent management method provided in the above embodiments of this application, correspondingly, the embodiments of this application also provide a battery pack pre-overcurrent management system, such as... Figure 3 As shown, the pre-overcurrent management system of the battery pack includes:

[0132] The acquisition unit 31 is used to acquire the battery pack allowance information of the parallel multi-branch battery pack of the electric vehicle in real time; wherein, the battery pack allowance information includes the branch allowance information of each branch of the parallel multi-branch battery pack; the branch allowance information includes the vehicle allowance power or vehicle allowance current of the branch.

[0133] The first judgment unit 32 is used to determine whether the branch meets the pre-overcurrent opening condition for each branch based on the branch allowable information and the actual branch usage information; wherein, the actual branch allowable information includes the actual power or actual current used by the branch.

[0134] The first calculation unit 33 is used to perform pre-overcurrent calculation based on the branch allowable information of the branch that meets the pre-overcurrent opening condition and the actual branch usage information of each branch if the branch meets the pre-overcurrent opening condition, so as to obtain the target branch allowable information of the branch that meets the pre-overcurrent opening condition; wherein, the target branch allowable information includes the target vehicle allowable power or the target vehicle allowable current of the branch.

[0135] The second calculation unit 34 is used to calculate the target vehicle allowable power or target vehicle allowable current of the branch that does not meet the pre-overcurrent opening condition, based on the vehicle allowable power or vehicle allowable current of each branch.

[0136] The charging or discharging control unit 35 is used to determine the vehicle allowable power or vehicle allowable current of the parallel multi-branch battery pack based on the target vehicle allowable power or target vehicle allowable current of each branch, and send the vehicle allowable power or vehicle allowable current of the parallel multi-branch battery pack to the vehicle controller of the electric vehicle, so that the vehicle controller can charge or discharge according to the vehicle allowable power or vehicle allowable current of the parallel multi-branch battery pack.

[0137] This application discloses a pre-overcurrent management system for a battery pack, which eliminates the need to adjust the allowable power of the vehicle's multi-branch battery packs connected in parallel, thereby avoiding limiting the total current output of the multi-branch battery packs and thus avoiding the corresponding power type of the vehicle. At the same time, the technical solution provided by this application does not require additional hardware, thereby avoiding additional costs.

[0138] Optionally, if the branch line allowable information includes the branch line's total vehicle allowable power, and the actual branch line usage information includes the branch line's actual usage power, where the actual usage power is the actual charging power or the actual discharging power, the first determination unit includes:

[0139] The second judgment unit is used to determine, for each branch, whether the allowable power of the whole vehicle is the allowable charging power of the whole vehicle or the allowable discharging power of the whole vehicle.

[0140] The third calculation unit is used to calculate the difference between the absolute value of the vehicle's allowed charging power and the actual charging power used by the branch if the allowed power of the whole vehicle is the allowed charging power of the whole vehicle.

[0141] The third judgment unit is used to determine whether the charging power difference is less than the actual charging power over-limit threshold of the branch.

[0142] The first determining unit is used to determine that the branch meets the pre-overcurrent opening condition if the charging power difference is less than the actual charging power over-limit threshold.

[0143] The second determining unit is used to determine that the branch does not meet the pre-overcurrent opening condition if the charging power difference is not less than the actual charging power over-limit threshold.

[0144] The fourth calculation unit is used to calculate the difference between the allowable charging and discharging power of the branch and the actual discharge power used by the branch if the allowable power of the whole vehicle is the allowable discharge power of the whole vehicle.

[0145] The fourth judgment unit is used to determine whether the discharge power difference is less than the actual discharge power over-limit threshold of the branch.

[0146] The third determining unit is used to determine if the discharge power difference is less than the actual discharge power over-limit threshold, and to determine if the branch meets the pre-overcurrent opening condition.

[0147] The fourth determining unit is used to determine if the branch does not meet the pre-overcurrent opening condition if the discharge power difference is not less than the actual discharge power over-limit threshold.

[0148] Optionally, if the branch allowable information includes the branch's vehicle allowable current, the actual branch usage information includes the branch's actual usage current, and the actual usage power is the actual usage charging current or the actual usage discharging current, the first determination unit includes:

[0149] The fifth judgment unit is used to determine for each branch whether the allowable current of the whole vehicle is the allowable charging current of the whole vehicle or the allowable discharging current of the whole vehicle.

[0150] The fifth calculation unit is used to calculate the difference between the absolute value of the vehicle charging current of the branch and the actual charging current of the branch if the allowable current of the whole vehicle is the allowable charging current of the whole vehicle.

[0151] The sixth judgment unit is used to determine whether the charging current difference is less than the actual charging current over-limit threshold of the branch.

[0152] The fifth determining unit is used to determine if the branch meets the pre-overcurrent opening condition if the charging current difference is less than the actual charging current over-limit threshold.

[0153] The sixth determining unit is used to determine that the branch does not meet the pre-overcurrent opening condition if the charging current difference is not less than the actual charging current over-limit threshold.

[0154] The sixth calculation unit is used to calculate the difference between the allowable charging and discharging current of the branch and the actual discharge current of the branch if the allowable current of the whole vehicle is the allowable discharge current of the whole vehicle.

[0155] The seventh judgment unit is used to determine whether the discharge current difference is less than the actual discharge current over-limit threshold of the branch.

[0156] The seventh determining unit is used to determine if the discharge current difference is less than the actual discharge current over-limit threshold, and to determine if the branch meets the pre-overcurrent opening condition.

[0157] The eighth determining unit is used to determine if the branch does not meet the pre-overcurrent opening condition if the discharge current difference is not less than the actual discharge current over-limit threshold.

[0158] Optionally, the first computing unit includes:

[0159] The seventh calculation unit is used to calculate the power quotient of the vehicle's allowable power and its actual power used in the branch that meets the pre-overcurrent opening condition; wherein, the vehicle's allowable power is the vehicle's allowable charging power or the vehicle's allowable discharging power, and the actual power used is the actual charging power or the actual discharging power used.

[0160] The eighth calculation unit is used to calculate the target vehicle allowable power of the branch that meets the pre-overcurrent opening condition based on the vehicle allowable power of the branch that meets the pre-overcurrent opening condition, the actual power used by each other branch and the power quotient; wherein, the other branches are the branches that are not included in the current calculation of the target vehicle allowable power, and the target vehicle allowable power is the target vehicle charging allowable power or the target vehicle discharging allowable power.

[0161] Optionally, the first computing unit includes:

[0162] The ninth calculation unit is used to calculate the quotient of the vehicle's allowable current and its actual operating current for the branch that meets the pre-overcurrent opening condition; wherein, the vehicle's allowable current is the vehicle's charging allowable current or the vehicle's discharging allowable current, and the actual operating current is the actual charging current or the actual discharging current.

[0163] The tenth calculation unit is used to calculate the target vehicle allowable current of the branch that meets the pre-overcurrent opening condition based on the vehicle allowable current of the branch that meets the pre-overcurrent opening condition, the actual operating current of each other branch, and the current quotient; wherein, the other branches are branches other than the branch corresponding to the target vehicle allowable power in each branch, and the target vehicle allowable power is the target vehicle charging allowable power or the target vehicle discharging allowable power.

[0164] Optionally, the pre-overcurrent management system for the battery pack provided in this application embodiment further includes:

[0165] The eighth judgment unit is used to re-detect the branch permission information and actual branch usage information of each branch that meets the pre-overcurrent opening condition, and to determine whether there is a branch that meets the pre-overcurrent closing condition among the branches that meet the pre-overcurrent opening condition based on the re-detected branch permission information and actual branch usage information of each branch that meets the pre-overcurrent opening condition.

[0166] Return to execution unit, used to return to the execution acquisition unit if it does not exist;

[0167] An update unit is used, if present, to update the vehicle's allowable power or allowable current of the parallel multi-branch battery pack based on the re-detected branch allowable information of each branch, and to send the updated vehicle allowable power or allowable current of the parallel multi-branch battery pack to the vehicle controller of the electric vehicle, so that the vehicle controller can charge or discharge according to the updated vehicle allowable power or allowable current of the parallel multi-branch battery pack; wherein, the re-detected branch allowable information of each branch includes the branch allowable information of branches that meet the pre-overcurrent opening condition and branches that do not meet the pre-overcurrent opening condition;

[0168] The power-down control unit is used to stop the pre-overcurrent calculation for branches that meet both the pre-overcurrent opening and pre-overcurrent closing conditions, and to control the BMS to power down when it detects that the pre-overcurrent calculation for branches that meet both the pre-overcurrent opening and pre-overcurrent closing conditions has been successfully stopped after a preset time period.

[0169] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple, and relevant parts can be referred to the descriptions in the method embodiments. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0170] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0171] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A pre-overcurrent management method for a battery pack, characterized in that, The method includes: Real-time acquisition of battery pack allowance information of parallel multi-branch battery packs of electric vehicles; wherein, the battery pack allowance information includes branch allowance information of each branch of the parallel multi-branch battery pack; the branch allowance information includes the vehicle allowance power or vehicle allowance current of the branch. For each branch, based on the branch's allowable information and actual branch usage information, it is determined whether the branch meets the pre-overcurrent activation condition; wherein, the actual branch usage information includes the branch's actual power or actual current. If the branch meets the pre-overcurrent opening condition, pre-overcurrent calculation is performed based on the branch allowable information of the branch that meets the pre-overcurrent opening condition and the actual branch usage information of each branch to obtain the target branch allowable information of the branch that meets the pre-overcurrent opening condition; wherein, the target branch allowable information includes the target vehicle allowable power or target vehicle allowable current of the branch. If the branch does not meet the pre-overcurrent opening condition, calculate the target vehicle allowable power or target vehicle allowable current of the branch that does not meet the pre-overcurrent opening condition based on the vehicle allowable power or vehicle allowable current of each branch. Based on the target allowable power or target allowable current of the vehicle for each of the aforementioned branches, the allowable power or allowable current of the parallel multi-branch battery pack is determined, and the allowable power or allowable current of the parallel multi-branch battery pack is sent to the vehicle controller of the electric vehicle, so that the vehicle controller can charge or discharge according to the allowable power or allowable current of the parallel multi-branch battery pack.

2. The method according to claim 1, characterized in that, If the branch allowable information includes the vehicle allowable power of the branch, the actual branch usage information includes the actual usage power of the branch, and the actual usage power is the actual charging power or the actual discharging power. For each branch, based on the branch's permission information and actual branch usage information, it is determined whether the branch meets the pre-overcurrent enabling condition, including: For each of the branches, determine whether the allowable power of the vehicle for the branch is the allowable charging power of the vehicle or the allowable discharging power of the vehicle. If the allowable power of the whole vehicle is the allowable charging power of the whole vehicle, calculate the difference in charging power between the absolute value of the allowable charging power of the whole vehicle of the branch and the actual charging power used by the branch. Determine whether the charging power difference is less than the actual charging power over-limit threshold of the branch; If the difference in charging power is less than the actual charging power over-limit threshold, it is determined that the branch meets the pre-overcurrent activation condition. If the difference in charging power is not less than the actual charging power over-limit threshold, it is determined that the branch does not meet the pre-overcurrent opening condition. If the allowable power of the whole vehicle is the allowable power of the whole vehicle discharge, calculate the difference between the allowable power of the whole vehicle charging and discharging of the branch and the actual discharge power used by the branch; Determine whether the discharge power difference is less than the actual discharge power over-limit threshold of the branch; If the discharge power difference is less than the actual discharge power over-limit threshold, it is determined that the branch meets the pre-overcurrent opening condition. If the difference in discharge power is not less than the threshold value for exceeding the actual discharge power limit, it is determined that the branch does not meet the pre-overcurrent activation condition.

3. The method according to claim 1, characterized in that, If the branch allowable information includes the vehicle allowable current of the branch, the actual branch usage information includes the actual usage current of the branch, and the actual usage power is the actual charging current or the actual discharging current. For each branch, based on the branch's permission information and actual branch usage information, it is determined whether the branch meets the pre-overcurrent enabling condition, including: For each of the branches, determine whether the allowable current of the whole vehicle in the branch is the allowable charging current of the whole vehicle or the allowable discharging current of the whole vehicle. If the allowable current of the whole vehicle is the allowable charging current of the whole vehicle, calculate the difference between the absolute value of the allowable charging current of the whole vehicle of the branch and the actual charging current used by the branch. Determine whether the charging current difference is less than the actual charging current over-limit threshold of the branch; If the difference in charging current is less than the actual charging current over-limit threshold, it is determined that the branch meets the pre-overcurrent activation condition. If the difference in charging current is not less than the actual charging current over-limit threshold, it is determined that the branch does not meet the pre-overcurrent opening condition. If the allowable current of the whole vehicle is the allowable discharge current of the whole vehicle, calculate the difference between the allowable charging and discharging current of the whole vehicle of the branch and the actual discharge current used by the branch. Determine whether the discharge current difference is less than the actual discharge current over-limit threshold of the branch; If the discharge current difference is less than the actual discharge current over-limit threshold, the branch is determined to meet the pre-overcurrent opening condition. If the difference in discharge current is not less than the threshold value of the actual discharge current exceeding the limit, it is determined that the branch does not meet the pre-overcurrent opening condition.

4. The method according to claim 2, characterized in that, The step of performing pre-overcurrent calculation based on the branch allowance information of branches that meet the pre-overcurrent activation conditions and the actual branch usage information of each branch to obtain the target branch allowance information of branches that meet the pre-overcurrent activation conditions includes: Calculate the power quotient of the vehicle's allowable power and its actual power used for the branch that meets the pre-overcurrent opening condition; wherein, the vehicle's allowable power is the vehicle's allowable charging power or vehicle's allowable discharging power, and the actual power used is the actual charging power or the actual discharging power used. Based on the vehicle's allowable power of the branch that meets the pre-overcurrent opening condition, the actual power used by each other branch, and the power quotient, the target vehicle allowable power of the branch that meets the pre-overcurrent opening condition is calculated; wherein, the other branches are branches other than the branch corresponding to the target vehicle allowable power in each of the branches, and the target vehicle allowable power is the target vehicle charging allowable power or the target vehicle discharging allowable power.

5. The method according to claim 3, characterized in that, The step of performing pre-overcurrent calculation based on the branch allowance information of branches that meet the pre-overcurrent activation conditions and the actual branch usage information of each branch to obtain the target branch allowance information of branches that meet the pre-overcurrent activation conditions includes: Calculate the quotient of the vehicle's allowable current and its actual operating current for the branch that meets the pre-overcurrent opening condition; wherein, the vehicle's allowable current is the vehicle's charging allowable current or vehicle's discharging allowable current, and the actual operating current is the actual charging current or the actual discharging current. Based on the vehicle allowable current of the branch that meets the pre-overcurrent opening condition, the actual operating current of each other branch, and the current quotient, calculate the target vehicle allowable current of the branch that meets the pre-overcurrent opening condition; wherein, the other branches are branches other than the branch corresponding to the target vehicle allowable current in each of the branches, and the target vehicle allowable current is the target vehicle charging allowable current or the target vehicle discharging allowable current.

6. The method according to claim 4, characterized in that, The method further includes: Re-detect the branch permission information and actual branch usage information of each branch that meets the pre-overcurrent opening condition, and based on the re-detected branch permission information and actual branch usage information of each branch that meets the pre-overcurrent opening condition, determine whether there are any branches that meet the pre-overcurrent closing condition among the branches that meet the pre-overcurrent opening condition. If it does not exist, return to execute the real-time acquisition of battery pack availability information for the parallel multi-branch battery pack of the electric vehicle; If present, the allowable power or allowable current of the parallel multi-branch battery pack is updated based on the re-detected branch allowable information of each branch, and the updated allowable power or allowable current of the parallel multi-branch battery pack is sent to the vehicle controller of the electric vehicle, so that the vehicle controller can charge or discharge according to the updated allowable power or allowable current of the parallel multi-branch battery pack; wherein, the re-detected branch allowable information of each branch includes the branch allowable information of branches that meet the pre-overcurrent opening condition and branches that do not meet the pre-overcurrent opening condition; Stop the pre-overcurrent calculation for branches that meet both the pre-overcurrent opening and pre-overcurrent closing conditions, and when the pre-overcurrent calculation for branches that meet both the pre-overcurrent opening and pre-overcurrent closing conditions is successfully stopped after a preset time period, control the BMS to power down.

7. A pre-overcurrent management system for a battery pack, characterized in that, The system includes: The acquisition unit is used to acquire in real time the battery pack allowable information of the parallel multi-branch battery pack of the electric vehicle; wherein, the battery pack allowable information includes the branch allowable information of each branch of the parallel multi-branch battery pack; the branch allowable information includes the vehicle allowable power or vehicle allowable current of the branch. The first judgment unit is used to determine, for each branch, whether the branch meets the pre-overcurrent opening condition based on the branch allowable information and the actual branch usage information; wherein, the actual branch usage information includes the actual power or actual current used by the branch. The first calculation unit is used to perform pre-overcurrent calculation based on the branch allowable information of the branch that meets the pre-overcurrent opening condition and the actual branch usage information of each branch if the branch meets the pre-overcurrent opening condition, so as to obtain the target branch allowable information of the branch that meets the pre-overcurrent opening condition; wherein, the target branch allowable information includes the target vehicle allowable power or the target vehicle allowable current of the branch. The second calculation unit is used to calculate the target vehicle allowable power or target vehicle allowable current of the branch that does not meet the pre-overcurrent opening condition, based on the vehicle allowable power or vehicle allowable current of each branch. A charging or discharging control unit is used to determine the vehicle allowable power or vehicle allowable current of the parallel multi-branch battery pack based on the target vehicle allowable power or target vehicle allowable current of each of the said branches, and send the vehicle allowable power or vehicle allowable current of the parallel multi-branch battery pack to the vehicle controller of the electric vehicle, so that the vehicle controller can charge or discharge according to the vehicle allowable power or vehicle allowable current of the parallel multi-branch battery pack.

8. The system according to claim 7, characterized in that, If the branch allowable information includes the vehicle allowable power of the branch, and the actual branch usage information includes the actual usage power of the branch, wherein the actual usage power is the actual charging power or the actual discharging power, the first determination unit includes: The second judgment unit is used to determine, for each of the branches, whether the allowable power of the whole vehicle is the allowable charging power of the whole vehicle or the allowable discharging power of the whole vehicle. The third calculation unit is used to calculate the difference in charging power between the absolute value of the vehicle's allowed charging power and the actual charging power used by the branch if the allowed power of the whole vehicle is the allowed charging power of the whole vehicle. The third judgment unit is used to determine whether the charging power difference is less than the actual charging power over-limit threshold of the branch. The first determining unit is used to determine that the branch meets the pre-overcurrent opening condition if the charging power difference is less than the actual charging power over-limit threshold. The second determining unit is used to determine that the branch does not meet the pre-overcurrent opening condition if the charging power difference is not less than the actual charging power over-limit threshold. The fourth calculation unit is used to calculate the difference between the allowable charging and discharging power of the branch and the actual discharge power used by the branch if the allowable power of the whole vehicle is the allowable discharge power of the whole vehicle. The fourth judgment unit is used to determine whether the discharge power difference is less than the actual discharge power over-limit threshold of the branch. The third determining unit is used to determine that the branch meets the pre-overcurrent opening condition if the discharge power difference is less than the actual discharge power over-limit threshold. The fourth determining unit is used to determine that the branch does not meet the pre-overcurrent opening condition if the discharge power difference is not less than the actual discharge power over-limit threshold.

9. The system according to claim 7, characterized in that, If the branch allowable information includes the vehicle allowable current of the branch, the actual branch usage information includes the actual usage current of the branch, and the actual usage power is the actual charging current or the actual discharging current, the first determination unit includes: The fifth judgment unit is used to determine, for each of the branches, whether the allowable current of the whole vehicle is the allowable charging current of the whole vehicle or the allowable discharging current of the whole vehicle. The fifth calculation unit is used to calculate the difference between the absolute value of the vehicle charging allowable current of the branch and the actual charging current used by the branch if the allowable current of the whole vehicle is the allowable charging current of the whole vehicle. The sixth judgment unit is used to determine whether the charging current difference is less than the actual charging current over-limit threshold of the branch. The fifth determining unit is used to determine that the branch meets the pre-overcurrent opening condition if the charging current difference is less than the actual charging current over-limit threshold. The sixth determining unit is used to determine that the branch does not meet the pre-overcurrent opening condition if the charging current difference is not less than the actual charging current over-limit threshold. The sixth calculation unit is used to calculate the difference between the allowable charging and discharging current of the branch and the actual discharge current of the branch if the allowable current of the whole vehicle is the allowable discharge current of the whole vehicle. The seventh judgment unit is used to determine whether the discharge current difference is less than the actual discharge current over-limit threshold of the branch. The seventh determining unit is used to determine that the branch meets the pre-overcurrent opening condition if the discharge current difference is less than the actual discharge current over-limit threshold. The eighth determining unit is used to determine that the branch does not meet the pre-overcurrent opening condition if the discharge current difference is not less than the actual discharge current over-limit threshold.

10. The system according to claim 8, characterized in that, The first computing unit includes: The seventh calculation unit is used to calculate the power quotient of the vehicle's allowable power and its actual power used in the branch that meets the pre-overcurrent opening condition; wherein, the vehicle's allowable power is the vehicle's allowable charging power or the vehicle's allowable discharging power, and the actual power used is the actual charging power or the actual discharging power used. The eighth calculation unit is used to calculate the target vehicle allowable power of the branch that meets the pre-overcurrent opening condition based on the vehicle allowable power of the branch that meets the pre-overcurrent opening condition, the actual power used by each other branch, and the power quotient; wherein, the other branches are branches other than the branch corresponding to the target vehicle allowable power in each of the branches, and the target vehicle allowable power is the target vehicle charging allowable power or the target vehicle discharging allowable power.

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