Battery management system and electronic equipment

Abstract

The utility model discloses a battery management system and electronic equipment, and the battery management system comprises a plurality of battery modules which are connected in parallel to form a plurality of parallel branches; the plurality of current detection modules are respectively arranged on the plurality of parallel branches, and the current detection modules are configured to detect the current of the corresponding parallel branches so as to obtain current detection values; the plurality of impedance modules are respectively connected with the plurality of battery modules; and the control module is connected with the plurality of current detection modules and the plurality of impedance modules, and the control module is configured to adjust the resistance value of at least one impedance module according to the plurality of current detection values, so that the currents of the plurality of parallel branches are equal, the consistency of the batteries can be maintained, and the service life of the battery system is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage, and particularly to a battery management system and an electronic device. Background Art

[0002] For a battery management system (BMS) adopting a parallel circuit, since the working environments of the batteries in each branch are inconsistent, the battery losses, battery performances, etc. of each branch are different. This leads to different magnitudes of current (charge and discharge rates) in each branch under a certain voltage, which will seriously affect the consistency of the battery cells and have a great impact on the service life of the battery management system. Summary of the Utility Model

[0003] To solve the above problems, the present application provides a battery management system and an electronic device, which can maintain the consistency of the batteries, thereby extending the service life of the battery system.

[0004] One technical solution adopted by the present application is: to provide a battery management system, which includes: a plurality of battery modules, and the plurality of battery modules are connected in parallel to form a plurality of parallel branches; a plurality of current detection modules, which are respectively arranged on the plurality of parallel branches, and the current detection modules are configured to detect the current of the corresponding parallel branch to obtain a current detection value; a plurality of impedance modules, which are respectively connected to the plurality of battery modules; a control module, which is connected to the plurality of current detection modules and the plurality of impedance modules, and the control module is configured to adjust the resistance value of at least one impedance module according to the plurality of current detection values, so that the currents of the plurality of parallel branches are equal.

[0005] In one embodiment, the control module is configured to: determine the average current value of the plurality of current detection values; adjust the resistance value of at least one impedance module, so that the currents of the plurality of parallel branches are the average current value.

[0006] In one embodiment, the control module is configured to: determine the first average current value of the plurality of current detection values; determine the current outlier with the largest difference from the first average current value among the plurality of current detection values; determine the second average current value of the remaining current detection values except the current outlier; adjust the resistance value of at least one impedance module, so that the currents of the plurality of parallel branches are the second average current value.

[0007] In one embodiment, the control module is configured to: determine the current difference between the current detection value and the average current value of the first target branch among the plurality of parallel branches; when the current difference is greater than the set threshold, adjust the resistance value of the impedance module of the first target branch, so that the current of the first target branch is the average current value.

[0008] In one embodiment, the control module is configured to: determine a second target branch corresponding to the minimum current among a plurality of current detection values; adjust the resistance value of at least one impedance module according to the minimum current, so that the currents of the plurality of parallel branches are equal.

[0009] In one embodiment, the control module is configured to: adjust the resistance values of the remaining impedance modules except the impedance module of the second target branch, so that the currents of the remaining parallel branches except the second target branch are the minimum current.

[0010] In one embodiment, the control module is configured to: adjust the resistance value of the impedance module of the second target branch, so that the current of the second target branch is a target current value; adjust the resistance values of the remaining impedance modules except the impedance module of the second target branch, so that the currents of the remaining parallel branches except the second target branch are the target current value.

[0011] In one embodiment, the plurality of impedance modules are respectively connected in series with a plurality of battery modules, and the control module is configured to: in response to the minimum current value being less than a preset reference current value, reduce the resistance value of the impedance module of the second target branch, so that the current of the second target branch increases to the target current value; or in response to the minimum current value being greater than or equal to the preset reference current value, use the minimum current value as the target current value.

[0012] In one embodiment, the plurality of impedance modules are respectively connected in series with a plurality of battery modules, and the control module is configured to: adjust the resistance value of the impedance module of the second target branch to 0, so that the current of the second target branch increases to the target current value.

[0013] Another technical solution adopted by this application is: to provide an electronic device, characterized in that the electronic device includes the battery management system as described above.

[0014] The battery management system provided by this application includes: a plurality of battery modules, and the plurality of battery modules are connected in parallel to form a plurality of parallel branches; a plurality of current detection modules, which are respectively arranged on the plurality of parallel branches, and the current detection modules are configured to detect the current of the corresponding parallel branch to obtain a current detection value; a plurality of impedance modules, which are respectively connected to the plurality of battery modules; a control module, which is connected to the plurality of current detection modules and the plurality of impedance modules, and the control module is configured to adjust the resistance value of at least one impedance module according to the plurality of current detection values, so that the currents of the plurality of parallel branches are equal. In the above manner, by changing the resistance value of the impedance module, the branch currents of each battery module can be made the same, which can improve the consistency of the battery cells. Since the charge and discharge rates of the battery cells in each branch are the same at all times, the sOC and sOH values can be estimated more accurately, reducing overcharge and over-discharge phenomena and prolonging the service life of the battery module. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0016] Figure 1 is a schematic structural diagram of the first embodiment of the battery management system provided by the present application;

[0017] Figure 2 is Figure 1 a schematic diagram of the principle of series connection of the corresponding battery module and impedance module;

[0018] Figure 3 is a schematic structural diagram of the second embodiment of the battery management system provided by the present application;

[0019] Figure 4 is Figure 3 a schematic diagram of the principle of parallel connection of the corresponding battery module and impedance module;

[0020] Figure 5 is a schematic structural diagram of an embodiment of an electronic device provided by the present application. Specific embodiments

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0022] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0023] ″A and / or B″ includes the following three combinations: only A, only B, and the combination of A and B.

[0024] The use of ″suitable for″ or ″configured to″ in this application means open and inclusive language, which does not exclude devices that are suitable for or configured to perform additional tasks or steps. Additionally, the use of ″based on″ means open and inclusive because a process, step, calculation, or other action ″based on″ one or more of the stated conditions or values can in practice be based on additional conditions or values beyond those stated.

[0025] In this application, the term ″exemplary″ is used to mean ″serving as an example, instance, or illustration″. Any embodiment described as ″exemplary″ in this application is not necessarily to be construed as more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use this application. In the following description, details are set forth for the purpose of explanation. It should be understood that those of ordinary skill in the art can recognize that this application can be implemented without these specific details. In other instances, well-known structures and processes are not elaborated in detail to avoid obscuring the description of this application with unnecessary details. Therefore, this application is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed in this application.

[0026] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of the first embodiment of the battery management system provided by this application. The battery management system 100 includes a plurality of battery modules (B1, B2......Bn), a plurality of impedance modules (R1, R2......Rn), and a control module 10.

[0027] Among them, a battery module generally includes a plurality of series-connected battery cells, and a plurality of battery modules are connected in parallel. Optionally, in this embodiment, n battery modules are taken as an example for illustration, specifically including a first battery module B1, a second battery module B2......a nth battery module Bn, and the first battery module B1, the second battery module B2......the nth battery module Bn are connected in parallel.

[0028] Among them, the number of impedance modules is the same as that of battery modules, and each impedance module is respectively connected to a corresponding battery module. Optionally, it specifically includes a first impedance module R1, a second impedance module R2......a nth impedance module Rn. The first impedance module R1 is connected to the first battery module B1, the second impedance module R2 is connected to the second battery module B2......the nth impedance module Rn is connected to the nth battery module Bn.

[0029] Optionally, in this embodiment, the corresponding impedance module and the battery module are connected in series. Specifically, the first impedance module R1 and the first battery module B1 are connected in series, the second impedance module R2 and the second battery module B2 are connected in series... the nth impedance module Rn and the nth battery module Bn are connected in series.

[0030] Optionally, the battery management system 100 further includes a plurality of current detection modules (A1, A2... An), each current detection module is respectively connected to a corresponding battery module, and a plurality of battery modules (B1, B2... Bn) are connected in parallel to form a plurality of parallel branches. Each current detection module is configured to detect the current flowing through a corresponding parallel branch to obtain a plurality of current detection values. Specifically, the first current detection module A1 and the first battery module B1 are connected in series and are used to detect the current flowing through the parallel branch corresponding to the first battery module B1. The second current detection module A2 and the second battery module B2 are connected in series and are used to detect the current flowing through the parallel branch corresponding to the second battery module B2... the nth current detection module An and the nth battery module Bn are connected in series and are used to detect the current flowing through the parallel branch corresponding to the nth battery module Bn.

[0031] Wherein, the control module 10 is connected to a plurality of impedance modules and a plurality of current detection modules. The control module 10 is configured to adjust the resistance value of the impedance module so that the currents of the plurality of parallel branches are equal. Specifically, the control module 10 is configured to adjust the resistance value of at least one impedance module according to a plurality of current detection values so that the currents of the plurality of parallel branches are equal.

[0032] Optionally, the battery modules (B1, B2... Bn), the impedance modules (R1, R2... Rn) and the current detection modules (A1, A2... An) are connected by electrical connection, and the control module 10 is connected to the plurality of impedance modules and the plurality of current detection modules by communication connection.

[0033] Specifically, the control module 10 may include a plurality of input pins and a plurality of output pins. The plurality of input pins are respectively connected to the plurality of current detection modules, and the plurality of output pins are respectively connected to the plurality of impedance modules.

[0034] For example, after detecting the current detection value, the current detection module can send a current detection signal to the corresponding input pin of the control module 10 through a communication link. The current detection signal is used to represent the current detection value; when the control module 10 needs to adjust the resistance value of a certain impedance module, it can send a resistance adjustment signal to the corresponding impedance module through the corresponding output pin through the communication link. The resistance adjustment signal can represent the amplitude of the increase / decrease of the resistance.

[0035] Combined withFigure 2 , Figure 2 is Figure 1 a schematic diagram of the principle of series connection of the corresponding battery module and impedance module.

[0036] Assume that the required power is P, the terminal voltage is U, the internal resistance of the battery module is R0, the resistance value of the impedance module is R, the current is I, and the sum of the terminal voltages of the battery cells in the module OCV is a fixed value. It can be obtained that:

[0037]

[0038] Furthermore, eliminating U gives:

[0039] P = OCV × I

[0040] Therefore, when the internal resistance R0 of the battery module is known, only by changing the current I can the required power be satisfied. Although the voltage U will fluctuate, its influence on the power can be eliminated by the current, and at the same time, it is ensured that the output power of R0 is always equal to the required power in real time.

[0041] Returning to Figure 1 the corresponding embodiment, when the currents flowing through multiple battery modules are equal, that is, the charge and discharge rates of each branch of the battery module are the same at all times, the estimation of its SOC (State of Charge, battery charge state) and SOH (State of Health, battery health state) values is more accurate, reducing the phenomenon of overcharging and over-discharging, and extending the service life of the battery pack.

[0042] In one embodiment, the control module 10 is configured to determine the average current of a plurality of current detection values; adjust the resistance values of at least one impedance module so that the currents of a plurality of parallel branches are the average current.

[0043] Specifically, the control module 10 obtains the first current I1 detected by the first current detection module A1, the first current I2 detected by the second current detection module A2... the first current In detected by the nth current detection module An, and then takes the average value:

[0044]

[0045] Then, the control module 10 sends signals to the first impedance module R1, the second impedance module R2... the nth impedance module Rn respectively, changing the resistance values of the first impedance module R1, the second impedance module R2... the nth impedance module Rn, so that I1′ = I2′ = … = I n ′ = I mean .

[0046] For example, the current of a certain branch is less than I mean, the resistance value of the corresponding impedance module is adjusted downward to increase the current of this branch to I mean , or, the current of a certain branch is greater than I mean , the resistance value of the corresponding impedance module is adjusted upward to reduce the current of this branch to I mean .

[0047] Optionally, the control module 10 is configured to: determine the current difference between the current detection value and the current average value of the first target branch among multiple parallel branches; when the current difference is greater than a set threshold, adjust the resistance value of the impedance module of the first target branch so that the current of the target branch is the current average value.

[0048] It can be understood that, due to the certain adjustment accuracy of the impedance module, when the current difference between the current detection value and the current average value of the target branch is small, that is, less than the set threshold, the impedance module of this branch may not be adjusted. Among them, the set threshold can be set based on the minimum adjustment accuracy of the impedance module.

[0049] In an application scenario, since the current of a certain parallel branch among multiple parallel branches may be abnormal, this current abnormality may be caused by various factors such as battery failure and line failure. Then, when performing current balancing, this parallel branch may be turned off or the fault may be restored, so this branch may not be considered when performing current balancing.

[0050] Optionally, in the above application scenario, the control module 10 is configured to: determine the first current average value of multiple current detection values; determine the current abnormality value with the largest difference from the first current average value among multiple current detection values; determine the second current average value of the remaining current detection values except the current abnormality value; adjust the resistance values of at least one impedance module so that the currents of multiple parallel branches are the second current average value.

[0051] Among them, the one with the largest difference from the first current average value among multiple current detection values is considered likely to be the current abnormality value. Then, this current abnormality value is removed and a new current average value, that is, the second current average value, is re-determined for subsequent current balancing adjustment.

[0052] In another embodiment, the control module 10 is configured to: determine the second target branch corresponding to the minimum current among multiple current detection values; adjust the resistance values of at least one impedance module according to the minimum current so that the currents of multiple parallel branches are equal.

[0053] For example, adjust the resistance values of the remaining impedance modules except the impedance module of the second target branch so that the currents of the remaining parallel branches except the second target branch are the minimum current.

[0054] For another example, adjust the resistance value of the impedance module of the second target branch so that the current of the second target branch is the target current value; adjust the resistance values of the remaining impedance modules except the impedance module of the second target branch so that the currents of the remaining parallel branches except the second target branch are the target current values.

[0055] Specifically, the control module 10 obtains the first current I1 detected by the first current detection module A1, the first current I2 detected by the second current detection module A2... the first current In detected by the nth current detection module An, and then takes the minimum value:

[0056] I min =min{I1, I2,..., I n}

[0057] Then, the control module 10 sends a signal to the target impedance module of the parallel branch corresponding to the minimum current to adjust the resistance value of the target impedance module so that the current of this branch is the target current value I fin .

[0058] It can be understood that since the battery modules and impedance modules of each branch in this embodiment are in series, therefore, in order to minimize the current of this branch, it is necessary to adjust the resistance value of the corresponding target impedance module to 0 so that the current flowing through the target battery module corresponding to the target impedance module increases to the target current value I fin .

[0059] Finally, send a signal to the remaining impedance modules to adjust the resistance values of the remaining impedance modules and adjust the currents of the remaining branches to I fin .

[0060] For example, if the current of a certain branch is less than I fin , then adjust the resistance value of the corresponding impedance module to be smaller to increase the current of this branch to I fin , or, if the current of a certain branch is greater than I fin , then adjust the resistance value of the corresponding impedance module to be larger to decrease the current of this branch to I fin .

[0061] In addition, when determining the target current value, the reference current value preset by the battery management system can be considered. This reference current value can be a safety current set based on overcurrent protection. For example, the reference current value can be a current value less than the overcurrent protection threshold.

[0062] Specifically, in response to the minimum current value being less than the preset reference current value, adjust the resistance value of the impedance module of the second target branch so that the current of the second target branch increases to the target current value; or in response to the minimum current value being greater than or equal to the preset reference current value, use the minimum current value as the target current value.

[0063] Understandably, when the minimum current value is less than the preset reference current value, in order to reduce the resistance loss and further reduce the heat loss, the resistance value of the impedance module of the second target branch is adjusted downwards so that the current of the second target branch increases to the target current value; when the minimum current value is greater than or equal to the preset reference current value, the current of this branch should not be further increased, so the resistance value of the impedance module of this branch remains unchanged, and the current of this branch also remains unchanged, taking the minimum current value as the target current value.

[0064] Optionally, the impedance module in the above embodiment may be a variable resistor, such as a potentiometer. A potentiometer (English: Potentiometer) is a type of variable resistor. It is usually composed of a resistance body and a rotating or sliding system, that is, a moving contact moves on the resistance body to obtain a partial voltage output.

[0065] Optionally, the current detection module in the above embodiment is a shunt. A shunt is an instrument for measuring direct current, which is made based on the principle that a voltage is generated across a resistor when direct current passes through it.

[0066] The battery management system provided in this embodiment includes: a plurality of battery modules, and the plurality of battery modules are connected in parallel to form a plurality of parallel branches; a plurality of current detection modules, which are respectively arranged on the plurality of parallel branches, and the current detection modules are configured to detect the current of the corresponding parallel branch to obtain a current detection value; a plurality of impedance modules, which are respectively connected to the plurality of battery modules; a control module, which is connected to the plurality of current detection modules and the plurality of impedance modules, and the control module is configured to adjust the resistance value of at least one impedance module according to the plurality of current detection values so that the currents of the plurality of parallel branches are equal. In the above manner, by changing the resistance value of the impedance module, the branch currents of each battery module can be made the same, which can improve the consistency of the battery cells. Since the charge and discharge rates of the battery cells in each branch are the same at all times, the sOC and sOH values can be estimated more accurately, reducing the phenomenon of overcharging and over-discharging and extending the service life of the battery module.

[0067] Please refer to Figure 3 , Figure 3 FIG. is a schematic structural diagram of the second embodiment of the battery management system provided by the present application. The battery management system 100 includes a plurality of battery modules (B1, B2......Bn), a plurality of impedance modules (R1, R2......Rn) and a control module 10.

[0068] Among them, a battery module generally includes multiple series-connected battery cells, and multiple battery modules are connected in parallel. Optionally, in this embodiment, n battery modules are taken as an example for illustration, specifically including a first battery module B1, a second battery module B2... a nth battery module Bn, and the first battery module B1, the second battery module B2... the nth battery module Bn are connected in parallel.

[0069] Among them, the number of impedance modules is the same as that of the battery modules, and each impedance module is respectively connected to a corresponding battery module. Optionally, it specifically includes a first impedance module R1, a second impedance module R2... an nth impedance module Rn. The first impedance module R1 is connected to the first battery module B1, the second impedance module R2 is connected to the second battery module B2... the nth impedance module Rn is connected to the nth battery module Bn.

[0070] Optionally, in this embodiment, the corresponding impedance module and the battery module are connected in parallel. Specifically, the first impedance module R1 and the first battery module B1 are connected in parallel, the second impedance module R2 and the second battery module B2 are connected in series... the nth impedance module Rn and the nth battery module Bn are connected in parallel.

[0071] Optionally, the battery management system 100 further includes multiple current detection modules (A1, A2... An), and each current detection module is respectively connected to a corresponding battery module. The multiple battery modules (B1, B2... Bn) are connected in parallel to form multiple parallel branches, and each current detection module is configured to detect the current flowing through a corresponding parallel branch to obtain multiple current detection values. Specifically, the first current detection module A1 is connected in series with the first battery module B1 and is used to detect the current flowing through the parallel branch corresponding to the first battery module B1. The second current detection module A2 is connected in series with the second battery module B2 and is used to detect the current flowing through the parallel branch corresponding to the second battery module B2... the nth current detection module An is connected in series with the nth battery module Bn and is used to detect the current flowing through the parallel branch corresponding to the nth battery module Bn.

[0072] Among them, the control module 10 is connected to multiple impedance modules and multiple current detection modules, and the control module 10 is configured to adjust the resistance value of the impedance module so that the currents of multiple parallel branches are equal. Specifically, the control module 10 is configured to adjust the resistance value of at least one impedance module according to multiple current detection values so that the currents of multiple parallel branches are equal.

[0073] Combined Figure 4 , Figure 4 is Figure 3 a schematic diagram of the principle of parallel connection of the corresponding battery module and the impedance module.

[0074] Assume that the required power is P, the terminal voltage is U, the internal resistance of the battery module is R0, the resistance value of the impedance module is R, the current is I, and the sum of the terminal voltages of the battery cells in the module OCV is a fixed value. It can be obtained that:

[0075]

[0076] Furthermore, eliminating U gives:

[0077] P = OCV × I

[0078] Therefore, when the internal resistance R0 of the battery module is known, only by changing the current I can the required power be satisfied. Although the voltage U will fluctuate, its influence on the power can be eliminated by the current, and at the same time, it is ensured that the output power of R0 is equal to the required power in real time.

[0079] Going back to Figure 3 the corresponding embodiment, when the currents flowing through multiple battery modules are equal, that is, the charge-discharge rates of each branch of the battery module are the same at all times, the estimation of its SOC (State of Charge) and SOH (State of Health) values is more accurate, reducing the phenomenon of overcharging and over-discharging, and extending the service life of the battery pack.

[0080] In one embodiment, the control module 10 is configured to determine the average current of a plurality of current detection values; adjust the resistance values of at least one impedance module so that the currents of a plurality of parallel branches are the average current.

[0081] Specifically, the control module 10 obtains the first current I1 detected by the first current detection module A1, the first current I2 detected by the second current detection module A2... the first current In detected by the nth current detection module An, and then takes the average value:

[0082]

[0083] Then, the control module 10 respectively sends signals to the first impedance module R1, the second impedance module R2... the nth impedance module Rn, changing the resistance values of the first impedance module R1, the second impedance module R2... the nth impedance module Rn, so that I1′ = I2′ = … = I n ′ = I mean .

[0084] For example, if the current of a certain branch is less than I mean , then the resistance value of the corresponding impedance module is increased to increase the current of this branch to I mean , or, if the current of a certain branch is greater than I mean , then the resistance value of the corresponding impedance module is decreased to reduce the current of this branch to Imean 。

[0085] Optionally, the control module 10 is configured to: determine the current difference between the current detection value and the average current value of the first target branch among multiple parallel branches; when the current difference is greater than a set threshold, adjust the resistance value of the impedance module of the first target branch so that the current of the target branch is the average current value.

[0086] Understandably, since the impedance module has a certain adjustment accuracy, when the current difference between the current detection value and the average current value of the target branch is small, that is, less than the set threshold, the impedance module of this branch may not be adjusted. Among them, the set threshold can be set based on the minimum adjustment accuracy of the impedance module.

[0087] In an application scenario, since the current of a certain parallel branch among multiple parallel branches is abnormal, this current abnormality may be caused by various factors such as battery failure and line failure. Then, when performing current balancing, this parallel branch may be turned off or the fault may be restored, so this branch may not be considered when performing current balancing.

[0088] Optionally, in the above application scenario, the control module 10 is configured to: determine the first average current value of multiple current detection values; determine the current abnormality value with the largest difference from the first average current value among multiple current detection values; determine the second average current value of the remaining current detection values except the current abnormality value; adjust the resistance value of at least one impedance module so that the current of multiple parallel branches is the second average current value.

[0089] Among them, the one with the largest difference from the first average current value among multiple current detection values is considered likely to be the current abnormality value. Then, this current abnormality value is removed and a new average current value, that is, the second average current value, is re-determined for subsequent current balancing adjustment.

[0090] In another embodiment, the control module 10 is configured to: determine the second target branch corresponding to the minimum current value among multiple current detection values; adjust the resistance value of at least one impedance module according to the minimum current value so that the current of multiple parallel branches is equal.

[0091] For example, adjust the resistance values of the remaining impedance modules except the impedance module of the second target branch so that the current of the remaining parallel branches except the second target branch is the minimum current value.

[0092] For another example, adjust the resistance value of the impedance module of the second target branch so that the current of the second target branch is the target current value; adjust the resistance values of the remaining impedance modules except the impedance module of the second target branch so that the current of the remaining parallel branches except the second target branch is the target current value.

[0093] Specifically, the control module 10 obtains the first current I1 detected by the first current detection module A1, the first current I2 detected by the second current detection module A2... the first current In detected by the nth current detection module An, and then takes the minimum value:

[0094] I min = min{I1, I2,..., I n}

[0095] Then, the control module 10 sends a signal to the target impedance module of the parallel branch corresponding to the minimum current to adjust the resistance value of the target impedance module, so that the current of this branch is the target current value I fin .

[0096] It can be understood that since the battery modules and impedance modules of each branch in this embodiment are in parallel, in order to minimize the current of this branch, it is necessary to adjust the resistance value of the corresponding target impedance module to an increasing value, so that the current flowing through the target battery module corresponding to the target impedance module increases to the target current value I fin .

[0097] Finally, a signal is sent to the remaining impedance modules to adjust the resistance values of the remaining impedance modules, and the currents of the remaining branches are all adjusted to I fin .

[0098] For example, if the current of a certain branch is less than I fin , then the resistance value of the corresponding impedance module is adjusted to increase to increase the current of this branch to I fin , or if the current of a certain branch is greater than I fin , then the resistance value of the corresponding impedance module is adjusted to decrease to reduce the current of this branch to I fin .

[0099] In addition, when determining the target current value, the reference current value preset by the battery management system can be considered. The reference current value can be a safety current set based on overcurrent protection. For example, the reference current value can be a current value less than the overcurrent protection threshold.

[0100] Specifically, in response to the minimum current value being less than the preset reference current value, the resistance value of the impedance module of the second target branch is adjusted to increase so that the current of the second target branch increases to the target current value; or in response to the minimum current value being greater than or equal to the preset reference current value, the minimum current value is used as the target current value.

[0101] Understandably, when the minimum current value is less than the preset reference current value, in order to reduce the resistance loss and further reduce the heat loss, the resistance value of the impedance module of the second target branch is adjusted downward so that the current of the second target branch increases to the target current value; when the minimum current value is greater than or equal to the preset reference current value, the current of this branch should not be further increased, so the resistance value of the impedance module of this branch remains unchanged, and the current of this branch also remains unchanged, and the minimum current value is used as the target current value.

[0102] Optionally, the impedance module in the above embodiment may be a variable resistor, such as a potentiometer. A potentiometer (English: Potentiometer) is a type of variable resistor. It is usually composed of a resistance body and a rotating or sliding system, that is, a moving contact moves on the resistance body to obtain a partial voltage output.

[0103] Optionally, the current detection module in the above embodiment is a shunt. A shunt is an instrument for measuring direct current. It is made based on the principle that a voltage is generated across a resistor when direct current passes through it.

[0104] The battery management system provided in this embodiment includes: a plurality of battery modules, and the plurality of battery modules are connected in parallel to form a plurality of parallel branches; a plurality of current detection modules, which are respectively arranged on the plurality of parallel branches, and the current detection modules are configured to detect the current of the corresponding parallel branch to obtain a current detection value; a plurality of impedance modules, which are respectively connected to the plurality of battery modules; a control module, which is connected to the plurality of current detection modules and the plurality of impedance modules, and the control module is configured to adjust the resistance value of at least one impedance module according to the plurality of current detection values so that the currents of the plurality of parallel branches are equal. In the above manner, by changing the resistance value of the impedance module, the branch currents of each battery module can be made the same, which can improve the consistency of the battery cells. Since the charge and discharge rates of the battery cells in each branch are the same at all times, the estimation of their SOC and SOH values is more accurate, reducing the phenomena of overcharging and over-discharging, and prolonging the service life of the battery module.

[0105] Refer to Figure 5 , Figure 5 is a schematic structural diagram of an embodiment of an electronic device provided by the present application. The electronic device 500 includes a battery management system 100.

[0106] Optionally, the electronic device 500 may be a new energy vehicle, such as a pure electric vehicle, an extended-range electric vehicle, a hybrid vehicle, a fuel cell electric vehicle, etc. By using the battery management system 100 of the above embodiment, the currents of the branches of the respective battery modules of the battery management system 100 are set to be the same, so as to satisfy that the output power of the module is equal to the required power in real time, and the consistency of the parallel battery management system 100 magnification is improved. Since the charge and discharge magnification of each branch of the battery cells is the same at all times, the estimation of the SOC and SOH values is more accurate, the overcharge and over-discharge phenomena are reduced, and the service life of the battery modules in the battery management system 100 is extended.

[0107] The display screen provided by the embodiments of the present application has been introduced in detail above. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A battery management system, characterized in that, The battery management system includes: A plurality of battery modules, and the plurality of battery modules are connected in parallel to form a plurality of parallel branches; A plurality of current detection modules, which are respectively arranged on the plurality of parallel branches, and the current detection module is configured to detect the current of the corresponding parallel branch to obtain a current detection value; A plurality of impedance modules, which are respectively connected to the plurality of battery modules; A control module, which is connected to the plurality of current detection modules and the plurality of impedance modules, and the control module is configured to adjust the resistance value of at least one of the impedance modules according to the plurality of current detection values so that the currents of the plurality of parallel branches are equal.

2. The battery management system according to claim 1, wherein The control module is signal-connected to the plurality of current detection modules and the plurality of impedance modules, and the control module is configured to: Determine the average current value of the plurality of current detection values respectively detected by the plurality of current detection modules; Adjust the resistance value of at least one of the impedance modules so that the currents of the plurality of parallel branches are the average current value.

3. The battery management system according to claim 2, characterized in that The control module includes a plurality of input pins and a plurality of output pins. The plurality of input pins are respectively connected to the plurality of current detection modules, and the plurality of output pins are respectively connected to the plurality of impedance modules. The control module is configured to: Determine the first average current value of the plurality of current detection values respectively detected by the plurality of current detection modules; Determine the current outlier with the largest difference from the first average current value among the plurality of current detection values; Determine the second average current value of the remaining current detection values except the current outlier among the plurality of current detection values respectively detected by the plurality of current detection modules; Adjust the resistance value of at least one of the impedance modules so that the currents of the plurality of parallel branches are the second average current value.

4. The battery management system according to claim 2, characterized in that, The control module includes a plurality of input pins and a plurality of output pins. The plurality of input pins are respectively connected to the plurality of current detection modules, and the plurality of output pins are respectively connected to the plurality of impedance modules. The control module is configured to: Determine the current difference between the current detection value detected by the current detection module of the first target branch among the plurality of parallel branches and the average current value; When the current difference is greater than the set threshold, adjust the resistance value of the impedance module of the first target branch so that the current of the first target branch is the average current value.

5. The battery management system according to claim 1, wherein The control module is signal-connected to the plurality of current detection modules and the plurality of impedance modules, and the control module is configured to: Determine the second target branch corresponding to the minimum current value among the plurality of current detection values respectively detected by the plurality of current detection modules; Adjust the resistance value of at least one of the impedance modules according to the minimum current value so that the currents of the plurality of parallel branches are equal.

6. The battery management system according to claim 5, characterized in that, The control module includes a plurality of input pins and a plurality of output pins. The plurality of input pins are respectively connected to the plurality of current detection modules, and the plurality of output pins are respectively connected to the plurality of impedance modules. The control module is configured to: Adjust the resistance values of the remaining impedance modules except the impedance module of the second target branch so that the current in the remaining parallel branches except the second target branch is the minimum current value.

7. The battery management system according to claim 5, characterized in that The control module includes a plurality of input pins and a plurality of output pins. The plurality of input pins are respectively connected to the plurality of current detection modules, and the plurality of output pins are respectively connected to the plurality of impedance modules. The control module is configured to: Adjust the resistance value of the impedance module of the second target branch so that the current in the second target branch is the target current value; Adjust the resistance values of the remaining impedance modules except the impedance module of the second target branch so that the current in the remaining parallel branches except the second target branch is the target current value.

8. The battery management system according to claim 7, wherein The plurality of impedance modules are respectively connected in series with the plurality of battery modules. The control module is configured to: In response to the minimum current value being less than the preset reference current value, reduce the resistance value of the impedance module of the second target branch so that the current in the second target branch increases to the target current value; Or In response to the minimum current value being greater than or equal to the preset reference current value, use the minimum current value as the target current value.

9. The battery management system according to claim 7, wherein The plurality of impedance modules are respectively connected in series with the plurality of battery modules. The control module is configured to: Adjust the resistance value of the impedance module of the second target branch to 0 so that the current in the second target branch increases to the target current value.

10. An electronic device, characterized in that, The electronic device includes the battery management system according to any one of claims 1-9.

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