Battery management methods and apparatus, battery systems, and computer-readable storage media

Abstract

This application provides a battery management method and apparatus, a battery system, and a computer-readable storage medium. The battery system includes: multiple parallel battery clusters, each battery cluster including: a battery pack; multiple DC-DC converters, each DC-DC converter's input terminal for electrical connection to a power source, with each DC-DC converter corresponding to one of the multiple battery clusters, and the output terminals of the corresponding DC-DC converters connected in series with the battery clusters; the multiple DC-DC converters include a main DC-DC converter; multiple bypass switches, each DC-DC converter corresponding to one of the multiple bypass switches, and the output terminals of the corresponding DC-DC converters connected in parallel with the bypass switches; and a battery status information acquisition unit for acquiring battery status information from each battery cluster and sending this information to the main DC-DC converter; the main DC-DC converter controls each DC-DC converter and each bypass switch based on the battery status information from each battery cluster. This battery system achieves effective inter-cluster equalization.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a battery management method and apparatus, a battery system, and a computer-readable storage medium. Background Technology

[0002] In energy storage systems, when multiple battery clusters are involved, DC-DC (Direct Current-Direct Current) converters are used to achieve balancing between battery clusters.

[0003] In traditional equalization schemes, the DC-DC converter is directly connected in series with the corresponding battery cluster. Therefore, when the battery system is running, the DC-DC converter is always in operation, resulting in high power consumption and limited control performance. Summary of the Invention

[0004] The purpose of this application is to provide a battery management method and device, a battery system, and a computer-readable storage medium to reduce system power consumption, maximize the control effect of DC-DC converter, and achieve effective inter-cluster balance.

[0005] In a first aspect, this application provides a battery system comprising: multiple parallel battery clusters, each battery cluster including: a battery pack; multiple DC-DC converters, the input terminals of each DC-DC converter being electrically connected to a power source, the multiple DC-DC converters corresponding one-to-one with the multiple battery clusters, and the output terminals of the corresponding DC-DC converters being connected in series with the battery clusters, the multiple DC-DC converters including a main DC-DC converter; multiple bypass switches, the multiple DC-DC converters corresponding one-to-one with the multiple bypass switches, and the output terminals of the corresponding DC-DC converters being connected in parallel with the bypass switches; a battery status information acquisition unit, the battery status information acquisition unit being used to acquire battery status information of each battery cluster and send the battery status information of each battery cluster to the main DC-DC converter; the main DC-DC converter being used to control each DC-DC converter and each bypass switch based on the battery status information of each battery cluster.

[0006] In this application, compared with the prior art, on the one hand, the DC-DC converter is equipped with a bypass switch. By opening or closing the bypass switch, the operation and non-operation of the DC-DC converter can be flexibly controlled, thereby reducing system power consumption and maximizing the control effect brought by different control strategies. On the other hand, the DC-DC converter includes a master DC-DC converter, which is equivalent to the DC-DC converter adopting a master-slave control method. Compared with the traditional method of a central controller controlling all DC-DC converters, both the control method and control strategy are more flexible, improving the adaptability of the entire battery system. Furthermore, this battery system can achieve effective inter-cluster equalization.

[0007] As one possible implementation, the plurality of DC-DC converters are pre-configured with codes, and the main DC-DC converter is the DC-DC converter corresponding to the largest or smallest code among the plurality of codes.

[0008] In this application, by configuring codes for multiple DC-DC converters, the main DC-DC converter can be determined simply and effectively based on the configured codes.

[0009] As one possible implementation, the power source is one or more battery packs in any battery cluster, and the input terminals of each DC-DC converter are connected in parallel with the power source.

[0010] In this application, the power source is one or more battery packs in any battery cluster, eliminating the need for a separate external power source and simplifying the circuit structure.

[0011] As one possible implementation, the battery status information includes: the voltage of each battery cluster before the battery system is powered on; the main DC-DC converter is specifically used to: determine the maximum and minimum voltages of each battery cluster; determine the voltage difference between the maximum and minimum voltages; if the voltage difference is less than a preset voltage, control each bypass switch to be closed; if the voltage difference is greater than the preset voltage, control each bypass switch to be open; control the DC-DC converter corresponding to the battery cluster with the maximum voltage to stabilize the voltage of the battery cluster with the maximum voltage to a first voltage, and control the DC-DC converter corresponding to the battery clusters other than the battery cluster with the maximum voltage to stabilize the voltage of the battery clusters other than the battery cluster with the maximum voltage to a second voltage, wherein the second voltage is greater than the first voltage.

[0012] In this application, the control strategy before the battery system is powered on can avoid circulating current and maintain the total voltage of each branch (battery cluster + the branch where the corresponding DC-DC converter is located) equal, thereby achieving inter-cluster voltage balance.

[0013] As one possible implementation, the battery system further includes multiple control switches, each corresponding to one of the multiple battery clusters, and the corresponding control switches are connected in series with the battery clusters. Before the battery system is powered on, each control switch is in an off state. The main DC-DC converter is also used to control each control switch to be turned on when each battery cluster is maintained at its corresponding voltage.

[0014] In this application, after determining that the total voltage of each branch is equal, that is, when the voltage between clusters is balanced, the entire battery system is powered on by turning on each control switch, thereby improving the safety of the battery system.

[0015] As one possible implementation, the battery status information includes: the voltage of each battery cluster when the battery system is charging; the main DC-DC converter is further configured to: control each bypass switch to be in an open state; control the DC-DC converter corresponding to the battery cluster with the maximum voltage to stabilize the voltage of the battery cluster with the maximum voltage to a first voltage; and control the DC-DC converters corresponding to the battery clusters other than the battery cluster with the maximum voltage to stabilize the current of the battery clusters other than the battery cluster with the maximum voltage to a value greater than a first preset current.

[0016] In this application, during charging, the control strategies of each DC-DC converter are used to stabilize the battery cluster corresponding to the maximum voltage to a first voltage and stabilize the current of other battery clusters to a first preset current, thereby achieving balance among battery clusters during charging.

[0017] As one possible implementation, the battery state information includes: the voltage of each battery cluster and the SOC (State of Charge) of each battery cluster when the battery system is discharging. The main DC-DC converter is further configured to: control each bypass switch to be in the open state; control each DC-DC converter to stabilize the current of the corresponding battery cluster to be less than a first preset current; if the SOC of each battery cluster is greater than the preset SOC; control each DC-DC converter to stabilize the voltage of the corresponding battery cluster to a preset voltage.

[0018] In this application, during discharge, the control strategy of each DC-DC converter first stabilizes the current of each cluster to be less than a first preset current. When the SOC of each cluster is greater than the preset SOC, the voltage of each cluster is then stabilized to the preset voltage, thereby achieving the balance between battery clusters under discharge conditions.

[0019] As one possible implementation, the battery state information includes: the SOC of each battery cluster after the battery system is powered on; the main DC-DC converter is specifically used to: determine the maximum SOC and minimum SOC among the SOCs of each battery cluster; determine the SOC difference between the maximum SOC and the minimum SOC; if the SOC difference is greater than a preset SOC value, control the bypass switch corresponding to the DC-DC converter of the first target battery cluster to be in an open state; the SOC of the first target battery cluster meets a preset SOC condition; control the DC-DC converter corresponding to the first target battery cluster to stabilize the current of the first target battery cluster to a second preset current.

[0020] In this application, in the charging and discharging plateau region of the battery system, it may be detected that the SOC difference between each cluster is too large. At this time, by controlling the DC-DC converter corresponding to the specified battery cluster to amplify or reduce the current of the specified battery cluster, the SOC of each cluster is balanced, thereby achieving SOC balance among the battery clusters in the plateau region.

[0021] As one possible implementation, the main DC-DC converter is further configured to: control each bypass switch to be in a closed state when the SOC of each battery cluster is the same as the average SOC of each battery cluster.

[0022] In this application, when the SOC of each battery cluster is the same as the average SOC of each battery cluster, it indicates that the SOC of each cluster has been balanced. At this time, by closing each bypass switch, the DC-DC converter can be controlled to not run, thereby reducing the system power consumption.

[0023] As one possible implementation, the battery status information also includes: whether each battery cluster meets a preset cutoff condition after the battery system is powered on; each bypass switch is in an open state; and the main DC-DC converter is specifically used to: if a battery cluster is detected to meet the preset cutoff condition, and the voltage regulation range of the DC-DC converter corresponding to the battery cluster meets the cutoff condition, control the DC-DC converter corresponding to the battery cluster to stabilize the battery cluster to a safe current operation.

[0024] In this application, after power-on, if a battery cluster reaches the cutoff condition and the voltage regulation range of the DC-DC converter corresponding to the battery cluster meets the cutoff condition, the battery cluster can be directly controlled to operate at a safe current, thereby achieving effective control of safe current operation and balance.

[0025] As one possible implementation, the main DC-DC converter is further configured to: if a battery cluster is detected to meet a preset cutoff condition, and the voltage regulation range of the DC-DC converter corresponding to the battery cluster does not meet the cutoff condition, reduce the power of each battery cluster; control the DC-DC converter corresponding to the second target battery cluster to adjust the current of the second target battery cluster to a safe current; wherein, if the battery system is in a charging state, the second target battery cluster is a fully charged battery cluster, and if the battery system is in a discharging state, the second target battery cluster is a fully discharged battery cluster; and control the bypass switch corresponding to the DC-DC converter corresponding to the second target battery cluster to be in a closed state.

[0026] In this application, if a battery cluster is detected to have reached the cutoff condition, and the voltage regulation range of the DC-DC converter corresponding to that battery cluster does not meet the cutoff condition, the power of each battery cluster is reduced first, and then the safe current is controlled. On the basis of ensuring the safety and stability of the system, the safe current operation and balanced control are achieved.

[0027] Secondly, this application provides a battery management method applied to the battery system described in the first aspect and any possible implementation thereof. The battery management method includes: acquiring battery status information of each battery cluster; and controlling each DC-DC converter and each bypass switch based on the battery status information of each battery cluster.

[0028] As one possible implementation, the battery status information includes: the voltage of each battery cluster before the battery system is powered on; controlling each DC-DC converter and each bypass switch based on the battery status information of each battery cluster includes: determining the maximum and minimum voltages among the voltages of each battery cluster; determining the voltage difference between the maximum and minimum voltages; if the voltage difference is less than a preset voltage, controlling each bypass switch to be closed; if the voltage difference is greater than the preset voltage, controlling each bypass switch to be open; controlling the DC-DC converter corresponding to the battery cluster corresponding to the maximum voltage to stabilize the voltage of the battery cluster corresponding to the maximum voltage to a first voltage, and controlling the DC-DC converter corresponding to the battery clusters other than the battery cluster corresponding to the maximum voltage to stabilize the voltage of the battery clusters other than the battery cluster corresponding to the maximum voltage to a second voltage, wherein the second voltage is greater than the first voltage.

[0029] As one possible implementation, the battery system further includes multiple control switches, each corresponding to one of the multiple battery clusters, and the corresponding control switches are connected in series with the battery clusters. Before the battery system is powered on, each control switch is in an off state. The battery management method further includes controlling each control switch to be turned on when each battery cluster is maintained at its corresponding voltage.

[0030] As one possible implementation, the battery status information includes: the voltage of each battery cluster when the battery system is charging; the control of each DC-DC converter and each bypass switch based on the battery status information of each battery cluster includes: controlling each bypass switch to be in an open state; controlling the DC-DC converter corresponding to the battery cluster with the maximum voltage to stabilize the voltage of the battery cluster with the maximum voltage to a first voltage; and controlling the DC-DC converters corresponding to the battery clusters other than the battery cluster with the maximum voltage to stabilize the current of the battery clusters other than the battery cluster with the maximum voltage to a value greater than a first preset current.

[0031] As one possible implementation, the battery state information includes: the voltage of each battery cluster and the state of charge (SOC) of each battery cluster when the battery system is discharging. The battery management method further includes: controlling each bypass switch to be in an open state; controlling each DC-DC converter to stabilize the current of the corresponding battery cluster to be less than a first preset current; and if the SOC of each battery cluster is greater than the preset SOC, controlling each DC-DC converter to stabilize the voltage of the corresponding battery cluster to a preset voltage.

[0032] As one possible implementation, the battery state information includes: the SOC of each battery cluster after the battery system is powered on; controlling each DC-DC converter and each bypass switch based on the battery state information of each battery cluster includes: determining the maximum SOC and minimum SOC among the SOCs of each battery cluster; determining the SOC difference between the maximum SOC and the minimum SOC; if the SOC difference is greater than a preset SOC value, controlling the bypass switch corresponding to the DC-DC converter of the first target battery cluster to be in an open state; the SOC of the first target battery cluster meets a preset SOC condition; controlling the DC-DC converter corresponding to the first target battery cluster to stabilize the current of the first target battery cluster to a second preset current.

[0033] As one possible implementation, the battery management method further includes: controlling each bypass switch to be in a closed state when the SOC of each battery cluster is the same as the average SOC of each battery cluster.

[0034] As one possible implementation, the battery status information further includes: whether each battery cluster meets a preset cutoff condition after the battery system is powered on; each bypass switch is in an open state; and controlling each DC-DC converter and each bypass switch based on the battery status information of each battery cluster includes: if a battery cluster is detected to meet the preset cutoff condition, and the voltage regulation range of the DC-DC converter corresponding to the battery cluster meets the cutoff condition, controlling the DC-DC converter corresponding to the battery cluster to stabilize the battery cluster to a safe current operation.

[0035] As one possible implementation, the battery management method further includes: if a battery cluster is detected to meet a preset cutoff condition, and the voltage regulation range of the DC-DC converter corresponding to the battery cluster does not meet the cutoff condition, reducing the power of each battery cluster; controlling the DC-DC converter corresponding to the second target battery cluster to adjust the current of the second target battery cluster to a safe current; wherein, if the battery system is in a charging state, the second target battery cluster is a fully charged battery cluster, and if the battery system is in a discharging state, the second target battery cluster is a fully discharged battery cluster; controlling the bypass switch corresponding to the DC-DC converter corresponding to the second target battery cluster to be in a closed state.

[0036] The technical effects that can be achieved by the second aspect and its various implementations are the same as those in the first aspect, and will not be repeated here.

[0037] Thirdly, this application provides a battery management device applied to the battery system described in the first aspect and any possible implementation thereof, the battery management device comprising: various functional modules for implementing the battery management method described in the second aspect and any possible implementation thereof.

[0038] Fourthly, this application provides a computer-readable storage medium storing a computer program, which, when executed by a computer, performs the battery management method as described in the second aspect and any possible implementation thereof. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1This is a schematic diagram of the energy storage system provided in the embodiments of this application;

[0041] Figure 2 This is a schematic diagram of the battery system provided in an embodiment of this application;

[0042] Figure 3 This is a schematic diagram illustrating the connection relationship between the encoder and the DC-DC converter provided in an embodiment of this application.

[0043] Figure 4 The coding flowchart provided for the embodiments of this application;

[0044] Figure 5 A first schematic diagram of the allowable capacity provided in the embodiments of this application;

[0045] Figure 6 A second schematic diagram of the allowable capacity provided in the embodiments of this application;

[0046] Figure 7 A flowchart of a battery management method provided in an embodiment of this application;

[0047] Figure 8 This is a schematic diagram of the structure of the battery management device provided in the embodiments of this application.

[0048] Icons: 1000 - Energy storage system; 200 - Battery system; 210 - Battery cluster; 220 - DC-DC converter; 230 - Bypass switch; 240 - Battery status information acquisition unit; 400 - Energy storage converter; 800 - Battery management device; 810 - Acquisition module; 820 - Processing module. Detailed Implementation

[0049] The technical solutions of the embodiments of this application will now be described with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of this application, and are therefore merely examples and should not be used to limit the scope of protection of this application.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0051] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0052] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0053] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0054] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0055] Currently, judging from market trends, the application of batteries is becoming increasingly widespread. Batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of the application areas of power batteries, the market demand for them is also constantly increasing.

[0056] In traditional energy storage system architectures, when multiple battery clusters are involved, converters are used to achieve balancing between the clusters. Taking DC-DC converters as an example, existing technologies connect the DC-DC converters directly in series with the corresponding battery clusters and set up a master controller for multiple DC-DC converters. Once the battery system is running, the master controller manages the control strategies of the multiple DC-DC converters.

[0057] The applicant discovered that while this method can achieve inter-cluster equalization of battery clusters, because multiple DC-DC converters are directly connected in series with their respective battery clusters, the DC-DC converters are placed within the branches of the battery clusters. Therefore, once the battery system is operational, the DC-DC converters are constantly running, resulting in an additional stage of power transmission loss, meaning the system's power consumption is relatively high.

[0058] Furthermore, in this architecture, multiple DC-DC converters are controlled by a single master controller, which has limitations in control methods and strategies, resulting in low adaptability.

[0059] After careful consideration, the applicant believes that the problem of high system power consumption can be avoided if the multiple DC-DC converters are not directly connected to the branches where the battery clusters are located; or if the connection or disconnection of the multiple DC-DC converters can be flexibly controlled.

[0060] Regarding the limitations of control methods and strategies, if multiple DC-DC converters no longer use a single main controller but instead adopt a master-slave control approach, then a separate external main controller is not required. This simplifies the circuit structure and improves control flexibility.

[0061] Based on the above considerations, the applicant designed a technical solution to reduce system power consumption, maximize the control effect of the DC-DC converter, and achieve effective inter-cluster equalization. This technical solution not only improves the architecture of the existing battery system but also enhances the control method of the DC-DC converter.

[0062] On the one hand, in addition to being connected in series with the corresponding battery pack, the DC-DC converter is also equipped with a bypass switch. By opening or closing the bypass switch, the operation of the DC-DC converter can be flexibly controlled. In this way, the DC-DC converter can be made independent of the battery pack branch, thereby reducing the system's power consumption and maximizing the control effects brought about by different control strategies.

[0063] On the other hand, multiple DC-DC converters adopt a master-slave control method, which is more flexible in terms of both control method and control strategy compared to the traditional method of a central controller controlling all DC-DC converters, thus improving the adaptability of the entire battery system.

[0064] Therefore, by adopting the technical solution provided in the embodiments of this application, the power consumption of the system is reduced, the control effect of the DC-DC converter is maximized, and effective inter-cluster balance is achieved.

[0065] The technical solutions provided in this application can be applied to energy storage systems, including but not limited to: energy storage power systems such as hydropower, thermal power, wind power and solar power plants; energy storage systems for electric vehicles such as electric bicycles, electric motorcycles, electric cars; and energy storage systems in multiple fields such as military equipment and aerospace.

[0066] Please refer to Figure 1This is a schematic diagram of the structure of the energy storage system 1000 provided in the embodiment of this application. The energy storage system 1000 includes: a battery system 200 and an energy storage converter 400 electrically connected to the battery system 200.

[0067] The energy storage converter 400 can control the charging and discharging process of the battery system 200, perform AC-DC conversion, and directly supply power to AC loads in the absence of a power grid.

[0068] In some embodiments, the energy storage converter 400 is a DC / AC energy storage converter. In other embodiments, the energy storage converter 400 may also be replaced by a load or bus DC-DC converter.

[0069] Based on the above introduction of the inventive concept and application scenarios, please refer to... Figure 2 This is a schematic diagram of the structure of the battery system 200 provided in the embodiments of this application.

[0070] like Figure 2 As shown, the battery system 200 includes:

[0071] Multiple battery clusters 210 connected in parallel; each battery cluster 210 includes a battery pack.

[0072] Multiple DC-DC converters 220; the input terminal of each DC-DC converter 220 is used to connect to a power source, the multiple DC-DC converters 220 correspond one-to-one with multiple battery clusters 210, and the output terminals of the corresponding DC-DC converters 220 and the battery clusters 210 are connected in series; the multiple DC-DC converters 220 include a main DC-DC converter.

[0073] Multiple bypass switches 230; multiple DC-DC converters 220 correspond one-to-one with multiple bypass switches 230, and the output terminals of the corresponding DC-DC converters 220 and bypass switches 230 are connected in parallel.

[0074] Battery status information acquisition unit 240.

[0075] The battery status information acquisition unit 240 is used to acquire the battery status information of each battery cluster 210 and send the battery status information of each battery cluster 210 to the main DC-DC converter; the main DC-DC converter is used to control each DC-DC converter 220 and each bypass switch 230 based on the battery status information of each battery cluster 210.

[0076] A battery pack comprises multiple batteries connected in series. A battery module can be formed by connecting multiple individual cells in series, parallel, or a combination thereof. Each individual cell can be a secondary or primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. Individual cells can be cylindrical, flat, cuboid, or other shapes.

[0077] Based on the series connection of multiple batteries, the battery cluster 210 can be understood as a branch formed by the series connection of multiple batteries.

[0078] The DC-DC converter 220 can be either an isolated DC-DC converter or a non-isolated DC-DC converter.

[0079] In this embodiment, the DC-DC converter 220 includes an input terminal and an output terminal, and has the capability of positive voltage output, negative voltage output, and both positive and negative voltage output.

[0080] The DC-DC converter 220 can be configured to be powered by an independent power supply or by a corresponding battery cluster 210.

[0081] The output of the DC-DC converter 220 can be connected in series with the positive and negative terminals of the corresponding battery cluster 210, or in the middle of multiple batteries.

[0082] In this embodiment of the application, the plurality of DC-DC converters 220 include a master DC-DC converter, and the other DC-DC converters 220 besides the master DC-DC converter are slave DC-DC converters.

[0083] In some embodiments, there is only one main DC-DC converter, meaning that all DC-DC converters 220 (including the main DC-DC converter itself) are controlled by this main DC-DC converter. This implementation is suitable for application scenarios with a small number of DC-DC converters 220; or, in other words, it is suitable for application scenarios where one DC-DC converter 220 can stably control multiple DC-DC converters 220.

[0084] In other embodiments, the number of master DC-DC converters may not be limited to one. As an optional implementation, multiple DC-DC converters 220 are grouped, for example, 20 DC-DC converters 220 are divided into 4 groups of 5 DC-DC converters 220 each. Each group then includes one master DC-DC converter; for example, in each group of 5 DC-DC converters 220, one is the master DC-DC converter, and the others are slave DC-DC converters. This implementation is suitable for applications with a large number of DC-DC converters 220; or, in other words, suitable for applications where one DC-DC converter 220 may not be able to stably control multiple DC-DC converters 220.

[0085] From the different implementations of master-slave control described above, it can be seen that when the master-slave control method is adopted, the control method of the DC-DC converter 220 can be flexibly configured according to different application scenarios, and the adaptability is high.

[0086] The bypass switch 230 can be in the form of a relay, an analog switch, etc., and is not limited in the embodiments of this application.

[0087] It can be understood that the output terminal of the DC-DC converter 220 is connected in parallel with its corresponding bypass switch 230, and in series with its corresponding battery cluster 210. This is equivalent to the bypass switch 230 and the corresponding battery cluster 210 being in series. Therefore, when the bypass switch 230 is closed, the bypass switch 230 is connected to the corresponding battery cluster 210, and the DC-DC converter 220 does not operate. When the bypass switch 230 is open, the DC-DC converter 220 is connected to the corresponding battery cluster 210, and the DC-DC converter 220 operates. Furthermore, even if the bypass switch 230 is open, the DC-DC converter 220 can still not operate; for example, in no-load disconnection and sleep states, the DC-DC converter 220 is equivalent to not being connected to the corresponding battery cluster 210.

[0088] The battery status information acquisition unit 240 is used to acquire battery status information of each battery cluster 210. The battery status information includes, but is not limited to, voltage, SOC, and current.

[0089] In some embodiments, the battery status information acquisition unit 240 includes a BMS (Battery Management System). In other embodiments, the battery status information acquisition unit 240 is a unified module of multiple information acquisition units. Alternatively, the battery status information acquisition unit 240 may also take other forms, which are not limited here.

[0090] In some embodiments, the battery status information acquisition unit 240 may be part of the battery. Therefore, in the entire battery system 200, there may be one or more battery status information acquisition units 240.

[0091] The battery status information acquisition unit 240 and each DC-DC converter 220 can be connected via communication lines to realize the interaction of battery status information.

[0092] After the main DC-DC converter receives the battery status information of each battery cluster 210, it combines the battery status information to generate control commands for each DC-DC converter 220 and each bypass switch 230, and each DC-DC converter 220 and each bypass switch 230 execute the corresponding control commands.

[0093] In this embodiment, compared with the prior art, on the one hand, the DC-DC converter 220 is equipped with a bypass switch 230. By opening or closing the bypass switch 230, the operation and non-operation of the DC-DC converter 220 can be flexibly controlled, thereby reducing the power consumption of the system and maximizing the control effect brought by different control strategies. On the other hand, the DC-DC converter 220 includes a master DC-DC converter, which is equivalent to the DC-DC converter 220 adopting a master-slave control method. Compared with the traditional method of a main controller controlling all DC-DC converters 220, both the control method and control strategy are more flexible, improving the adaptability of the entire battery system 200. Furthermore, the battery system 200 can achieve effective inter-cluster equalization.

[0094] In this embodiment of the application, since each DC-DC converter 220 adopts a master-slave control method, the master DC-DC converter needs to be determined in advance.

[0095] As an optional implementation, multiple DC-DC converters 220 are pre-configured with codes, and the main DC-DC converter is the DC-DC converter 220 corresponding to the largest or smallest code among the multiple codes.

[0096] In this implementation, multiple DC-DC converters 220 can be encoded first, and then the main DC-DC converter can be determined based on the encoding of the multiple DC-DC converters 220.

[0097] It is understandable that, in addition to determining the DC-DC converter 220 with the maximum or minimum code as the main DC-DC converter, other DC-DC converters 220 with specified codes can also be determined as the main DC-DC converter.

[0098] The encoding method of the DC-DC converter 220 will be introduced next.

[0099] Please refer to Figure 3 This is a schematic diagram of the encoding hardware architecture provided in an embodiment of this application. Figure 3 In this configuration, the DC-DC converter 220 is connected to the encoder via a hardwired connection. In some embodiments, the encoder is integrated into the BMS.

[0100] Please refer to Figure 4 This is a flowchart of the coding process provided in an embodiment of this application. Figure 4 In the diagram, DCDC refers to DC-DC converter 220, and the encoder is the main execution entity of the process on the left, while the DC-DC converter 220 is the main execution entity of the process on the right. This encoding process includes:

[0101] The encoder receives the encoding command and starts encoding.

[0102] Initialization encoding: The encoder sends a release encoding command to the DC-DC converter 220, and the DC-DC converter 220 exits encoding and pulls the output hard line low. Initialization encoding can be understood as a way to reset encoding. Through this initialization encoding, a new encoding process can be started, avoiding any other encoding processes before receiving the encoding command.

[0103] Encoding process: After the encoder begins encoding the DC-DC converter 220, it sequentially pulls the hardwire of each DC-DC converter 220 high. Each DC-DC converter 220, upon detecting the high hardwire, sends an encoding request command. Upon receiving the encoding request command, the encoder configures an encoding for the corresponding DC-DC converter 220. After receiving the encoding, the DC-DC converter 220 records the encoding and sends it back to the encoder for confirmation. After confirmation, the encoder continues encoding for the next DC-DC converter 220. After each DC-DC encoder successfully encodes, it saves the encoding; otherwise, it retains the original encoding value.

[0104] After the DC-DC converter 220 sends an encoding request instruction to the encoder, the encoder will also determine whether the DC-DC converter 220 has already been encoded. The determination is based on the Matchingcode carried in the encoding request instruction. If the Matchingcode matches the code to be configured, it means that the DC-DC converter 220 has been encoded; if they do not match, it means that the DC-DC converter 220 has not been encoded.

[0105] In addition, this coding process also involves some routine operations, such as startup timeout and query timeout, which can be flexibly set according to specific application scenarios and are not limited here.

[0106] In addition to the encoding methods mentioned above, other encoding methods may also be used, which are not limited here.

[0107] Regardless of the encoding method used, the encoding of the DC-DC converter 220 and the configuration of the main DC-DC converter are usually completed before leaving the factory.

[0108] In this embodiment of the application, by configuring codes for multiple DC-DC converters 220, the main DC-DC converter can be determined simply and effectively based on the configured codes.

[0109] In other embodiments, the DC-DC converter 220 may be configured directly by the manufacturer without the need for coding.

[0110] In this embodiment, the input terminal of the DC-DC converter 220 is used to connect to a power source. As an optional implementation, the power source is one or more battery packs in any battery cluster 210, and the input terminal of the DC-DC converter 220 is connected in parallel with the power source.

[0111] In this implementation, one or more battery packs in the battery cluster 210 are used as the power source for the DC-DC converter 220. The battery cluster 210 here can be a battery cluster 210 corresponding to each DC-DC converter 220, or it can be a non-corresponding battery cluster 210.

[0112] In this embodiment, the power source is one or more battery packs in any battery cluster 210, eliminating the need for a separate external power source and simplifying the circuit structure.

[0113] In other embodiments, the power source may also be an additional independent battery or battery pack, supercapacitor, DC bus, etc., which are not limited here.

[0114] The above embodiments have clarified the implementation of the hardware architecture of the battery system 200. Next, the implementation of the master-slave control of the battery system 200 in different application scenarios will be introduced.

[0115] In the first application scenario, before the battery system 200 is powered on, the total voltage of each branch is kept equal. Here, each branch refers to the battery cluster 210 branch + the DC-DC converter 220 branch. Correspondingly, the total voltage refers to the battery cluster 210 voltage + the DC-DC converter 220 voltage.

[0116] In this application scenario, the main DC-DC converter controls each DC-DC converter 220 to either switch on (i.e., the DC-DC converter 220 is working) or bypass (i.e., the DC-DC converter 220 is not working) based on battery status information. Bypass operation means that after a DC-DC converter 220 has been running for a period of time, if the voltage has reached the required level, the DC-DC converter 220 can stop operating, thus reducing system power consumption.

[0117] In this application scenario, the battery system 200 is not powered on. Each battery cluster 210 branch of the battery system 200 is also equipped with a control switch, which can be a relay. Initially, the control switches of each battery cluster 210 branch are in the open state, and the battery system 200 is not powered on. When the control switches of each battery cluster 210 branch are in the closed state, the battery system 200 is powered on.

[0118] The state control of the control switch, or the control of the control switch, can be achieved through the battery management system.

[0119] As an optional implementation, the battery status information includes the voltage of each battery cluster 210 before the battery system 200 is powered on. The master-slave control process of the master DC-DC converter includes: determining the maximum and minimum voltages among the voltages of each battery cluster 210; determining the voltage difference between the maximum and minimum voltages; if the voltage difference is less than a preset voltage, controlling each bypass switch 230 to be closed; if the voltage difference is greater than the preset voltage, controlling each bypass switch 230 to be open; controlling the DC-DC converter 220 corresponding to the battery cluster 210 with the maximum voltage to stabilize the voltage of the battery cluster 210 with the maximum voltage to a first voltage, and controlling the DC-DC converters 220 corresponding to the battery clusters 210 other than the battery cluster 210 with the maximum voltage to stabilize the voltage of the battery clusters 210 other than the battery cluster 210 with the maximum voltage to a second voltage, wherein the second voltage is greater than the first voltage.

[0120] In some embodiments, each DC-DC converter 220 is woken up by a wake-up source before the battery system 200 is powered on. The wake-up source may be the battery management system or other configured modules.

[0121] In this control process, after the main DC-DC converter obtains the voltage of each battery cluster 210 from the battery status information acquisition unit 240, it compares the voltages of each battery cluster 210 to determine the maximum and minimum voltages of each battery cluster 210. Then, it calculates the voltage difference between the maximum and minimum voltages and performs master-slave control based on the voltage difference.

[0122] The preset voltage can be understood as a voltage threshold to avoid excessive circulating current. It can have different values ​​in different application scenarios. For example, it can be preset based on the actual conditions of the battery and the DC-DC converter 220. As an optional implementation, the preset voltage is 20V.

[0123] If the voltage difference is less than the preset voltage, it means that the voltage difference will not generate excessive circulating current. At this time, the DC-DC converter 220 does not need to work, and it is sufficient to control each bypass switch 230 to be in the closed state.

[0124] If the voltage difference is greater than the preset voltage, the voltage difference will cause excessive circulating current. At this time, the bypass switches 230 are controlled to be in the open state so that the DC-DC converters 220 can start working.

[0125] In constant voltage control, the constant voltage method for the battery cluster 210 corresponding to the maximum voltage is different from that for the other battery clusters 210. Specifically, the voltage of the battery cluster 210 corresponding to the maximum voltage is stable at a first voltage, while the voltage of the other battery clusters 210 is stable at a second voltage, and the second voltage is greater than the first voltage.

[0126] As an alternative implementation, assuming the first voltage is Us, the second voltage can be expressed as: Us + (Umax - U), where Umax is the maximum voltage and U is the voltage of this battery cluster 210. Us is the minimum voltage that the DC-DC converter 220 can output, for example, 5V.

[0127] In this embodiment, the control strategy before the battery system 200 is powered on can avoid circulating current and maintain the total voltage of each branch (the branch where the battery cluster 210 and the corresponding DC-DC converter 220 are located) equal, thereby achieving inter-cluster voltage balance.

[0128] As an optional implementation, the battery system 200 includes multiple control switches, each corresponding to one of the multiple battery clusters 210, and the corresponding control switches are connected in series with the battery clusters 210. Before the battery system 200 is powered on, each control switch is in the off state. Therefore, the control of the main DC-DC converter also includes: controlling each control switch to be turned on while each battery cluster 210 maintains its corresponding voltage.

[0129] Each battery cluster 210 is maintained at its corresponding voltage. For example, the battery cluster 210 with the maximum voltage is maintained at the first voltage, while the other battery clusters 210 are maintained at the second voltage.

[0130] In this embodiment of the application, after determining that the total voltage of each branch is equal, that is, when the voltage between clusters is balanced, the entire battery system 200 is powered on by turning on each control switch, thereby improving the safety of the battery system 200.

[0131] After all control switches are turned on, the battery system 200 is powered on. At this time, the entire battery system 200 may enter a charging or discharging state. This leads to the second application scenario: master-slave control of the main DC-DC converter during battery charging or discharging.

[0132] As an optional implementation, the battery status information includes the voltage of each battery cluster 210 when the battery system 200 is charging. The master-slave control process of the main DC-DC converter includes: controlling each bypass switch 230 to be in the open state; controlling the DC-DC converter 220 corresponding to the battery cluster 210 with the maximum voltage to stabilize the voltage of the battery cluster 210 with the maximum voltage to a first voltage; and controlling the DC-DC converters 220 corresponding to the battery clusters 210 other than the battery cluster 210 with the maximum voltage to stabilize the current of the battery clusters 210 other than the battery cluster 210 with the maximum voltage to a value greater than a first preset current.

[0133] During this control process, after each bypass switch 230 is opened, each DC-DC converter 220 starts to work. The voltage of the battery cluster 210 corresponding to the maximum voltage is maintained at the first voltage (i.e., the minimum voltage that the DC-DC converter 220 can output, as described in the previous embodiment), and the current of the other battery clusters 210 is stabilized at a value greater than the first preset current.

[0134] The value of the first preset current can be configured according to different application scenarios, and its value is not limited here.

[0135] In this embodiment of the application, during charging, the control strategy of each DC-DC converter 220 is used to stabilize the battery cluster 210 corresponding to the maximum voltage to the first voltage, and to stabilize the current of other battery clusters 210 to the first preset current, thereby achieving balance among the battery clusters 210 during charging.

[0136] Furthermore, during the charging process, if the voltage of the battery cluster 210 corresponding to the maximum voltage is stably maintained at the first voltage, and the current of the other battery clusters 210 is stably greater than the first preset current, that is, after the balancing between the battery clusters 210 has been completed, the main DC-DC converter can also start from the battery cluster 210 with the lowest current and sequentially switch the corresponding DC-DC converter 220 to bypass operation.

[0137] As an optional implementation, the battery status information includes: the voltage of each battery cluster 210 and the state of charge (SOC) of each battery cluster 210 when the battery system 200 is discharging. The master-slave control process of the main DC-DC converter includes: controlling each bypass switch 230 to be in the open state; controlling each DC-DC converter 220 to stabilize the current of the corresponding battery cluster 210 to be less than a first preset current; determining that the SOC of each battery cluster 210 is greater than the preset SOC; and controlling each DC-DC converter 220 to stabilize the voltage of the corresponding battery cluster 210 to a preset voltage.

[0138] In this control process, each bypass switch 230 is first turned off, causing each DC-DC converter 220 to start working. Then, each DC-DC converter 220 is controlled to stabilize the current of the corresponding battery cluster 210 to be less than a first preset current, where the first preset current refers to the implementation method of the first preset current in the aforementioned charging process.

[0139] After constant current control is performed, it is determined whether the SOC of each battery cluster 210 is greater than the preset SOC. The preset SOC can be understood as the SOC of the battery system 200 charging and discharging platform area, which can be set according to different application scenarios.

[0140] The plateau region can be understood as a range that a battery will experience during charging or discharging. Once charging or discharging enters the plateau region, the voltage change is very small or basically unchanged.

[0141] If the SOC of each battery cluster 210 is greater than the preset SOC, it indicates that the system has entered the plateau region. At this time, each DC-DC converter 220 is controlled to perform constant voltage control, that is, each DC-DC converter 220 is controlled to stabilize the voltage of the corresponding battery cluster 210 to the preset voltage. The implementation method of the preset voltage is as described in the previous embodiments and will not be repeated here.

[0142] In this embodiment of the application, during discharge, the control strategy of each DC-DC converter 220 is used to first stabilize the current of each cluster to be less than the first preset current. When the SOC of each cluster is greater than the preset SOC, the voltage of each cluster is then stabilized to the preset voltage, thereby achieving the balance between the battery clusters 210 under the discharge state.

[0143] In addition, during the discharge process, after the equalization between battery clusters 210 is completed, the main DC-DC converter can also switch the corresponding DC-DC converters 220 to bypass operation sequentially starting from the battery cluster 210 with the highest current.

[0144] In the embodiments of this application, after charging or discharging enters the plateau region, the SOC of each cluster may also be different; or even if it does not enter the plateau region, the SOC of each cluster may also be different. Therefore, in the third application scenario, the master DC-DC converter needs to achieve the balance of SOC of each cluster through master-slave control.

[0145] As an optional implementation, the battery status information includes the state of charge (SOC) of each battery cluster 210 after the battery system 200 is powered on. The master-slave control process of the master DC-DC converter includes: determining the maximum and minimum SOC among the SOCs of each battery cluster 210; determining the SOC difference between the maximum and minimum SOCs; if the SOC difference is greater than a preset SOC value, controlling the bypass switch 230 corresponding to the DC-DC converter 220 corresponding to the first target battery cluster to be in the open state; the SOC of the first target battery cluster meets the preset SOC condition; controlling the DC-DC converter 220 corresponding to the first target battery cluster to stabilize the current of the first target battery cluster to a second preset current.

[0146] In this control process, the main DC-DC converter acquires the SOC of each battery cluster 210 from the battery state information acquisition unit 240, then compares the SOC of each battery cluster 210 to determine the maximum and minimum SOC. Next, it calculates the SOC difference between the maximum and minimum SOC, and then performs equalization control based on the SOC difference.

[0147] Equalization control is only required when the SOC difference is greater than the preset SOC value. The preset SOC value can be set according to the specific application scenario, and its value is not limited here.

[0148] In this embodiment of the application, the SOC balance can be adjusted according to clusters, that is, it is not necessary to adjust all clusters, but only the SOC of the first target battery cluster needs to be adjusted.

[0149] In some embodiments, the preset SOC condition is: arranging the SOC of all battery clusters 210 in descending order, and sorting the SOC of the first n positions, where n is a positive integer greater than 1, which can be determined in combination with the total number of battery clusters 210. For example, if the total number of battery clusters 210 is 5, n can be 2.

[0150] For example, when n is 2, the first target battery cluster is the battery cluster 210 corresponding to the largest SOC and the second largest (second largest) SOC.

[0151] In other embodiments, the preset SOC condition is: the difference between the maximum SOC and the minimum SOC is greater than a preset difference.

[0152] It is understood that the preset SOC conditions can also be other conditions, which are not limited in the embodiments of this application.

[0153] After the bypass switch 230 corresponding to the DC-DC converter 220 corresponding to the first target battery cluster is in the open state, the DC-DC converter 220 corresponding to the first target battery cluster starts to work.

[0154] The DC-DC converter 220 corresponding to the first target battery cluster is controlled to stabilize the current of the first target battery cluster to a second preset current, thereby achieving constant current control of the first target battery cluster.

[0155] As an optional implementation, if the current battery system 200 is in a charging state, the second preset current is expressed as: (Is-a*I0) / b*j. Where, Is represents the total current of the multiple battery clusters 210, a is the number of other battery clusters 210 besides the first target battery cluster, I0 is the maximum allowable current of a single cluster, b is the number of the first target battery cluster, and j is the safety margin.

[0156] In some embodiments, the safety margin is 0.95. In other embodiments, the safety margin may also be set according to the application scenario, and is not limited in this application embodiment.

[0157] As another optional implementation, if the current battery system 200 is in a discharging state, the second preset current is: a*j.

[0158] In this embodiment of the application, in the charging and discharging platform area of ​​the battery system 200, it may be detected that the SOC difference of each cluster is too large. At this time, by controlling the DC-DC converter 220 of the specified battery cluster, the current of the specified battery cluster is amplified or reduced to balance the SOC of each cluster, thereby achieving SOC balance among the battery clusters 210 in the platform area.

[0159] As an optional implementation, the master-slave control process described above further includes: when the SOC of each battery cluster 210 is the same as the average SOC of each battery cluster 210, controlling each bypass switch 230 to be in a closed state.

[0160] In this embodiment of the application, when the SOC of each battery cluster 210 is the same as the average SOC of each battery cluster 210, it indicates that the SOC of each cluster has been balanced. At this time, by closing each bypass switch 230, the DC-DC converter 220 can be controlled not to run, thereby reducing the system power consumption.

[0161] In another embodiment, the adjustment time of the DC-DC converter 220 is set before adjustment begins, and the DC-DC converter 220 is switched to bypass operation when the adjustment time reaches the value.

[0162] In another embodiment, the DC-DC converter 220 can be switched off for bypass operation when the SOC value of each battery cluster 210 reaches the SOC value at the end of the plateau region (which can be preset). Since there may be cases where equalization is not completed even at the end of the plateau region, this implementation method can avoid the plateau region not achieving effective SOC equalization.

[0163] In this application embodiment, a fourth application scenario is also involved: when the charging and discharging is at the end, if the battery cluster 210 reaches the cutoff condition, the main DC-DC converter, through master-slave control, enables a single cluster to maintain safe current operation or disconnect, while other clusters continue to charge or discharge.

[0164] As an optional implementation, the battery status information also includes: whether each battery cluster 210 meets the preset cutoff condition after the battery system 200 is powered on; each bypass switch 230 is in the open state; the control process of the main DC-DC converter includes: if a battery cluster 210 is detected to meet the preset cutoff condition, and the voltage regulation range of the DC-DC converter 220 corresponding to the battery cluster 210 meets the cutoff condition, the DC-DC converter 220 corresponding to the battery cluster 210 is controlled to stabilize the battery cluster 210 to operate at a safe current.

[0165] During this control process, when a cluster reaches the cutoff condition and the corresponding DC-DC converter 220 has a sufficient voltage regulation range, it can maintain safe current operation.

[0166] Whether the cutoff condition has been met can be determined by the main DC-DC converter in real time, or by the battery management system detecting and informing the main DC-DC converter.

[0167] The safe current can be zero current or any other current value that can ensure safe operation.

[0168] In this embodiment of the application, after power-on, if the single battery cluster 210 reaches the cutoff condition and the voltage regulation range of the corresponding DC-DC converter 220 meets the cutoff condition, the battery cluster 210 can be directly controlled to operate at a safe current, thereby achieving effective control of safe current operation and balance.

[0169] As another optional implementation, the control process further includes: if a battery cluster 210 is detected to meet a preset cutoff condition, and the voltage regulation range of the DC-DC converter 220 corresponding to the battery cluster 210 does not meet the cutoff condition, reducing the power of each battery cluster 210; controlling the DC-DC converter 220 corresponding to the second target battery cluster to adjust the current of the second target battery cluster to a safe current; wherein, if the battery system 200 is in a charging state, the second target battery cluster is a fully charged battery cluster 210, and if the battery system 200 is in a discharging state, the second target battery cluster is a fully discharged battery cluster 210; controlling the bypass switch 230 corresponding to the DC-DC converter 220 corresponding to the second target battery cluster to be in a closed state.

[0170] In this control process, reducing the power of each battery cluster 210 includes: the main DC-DC converter requesting the battery system 200 to reduce its power by 1 / N, where N is the number of currently operating battery clusters 210. In the energy storage system 1000, the battery system 200 generally inputs or outputs power according to a set power. When a cluster is not working, a corresponding power reduction request needs to be made; otherwise, it will cause overcurrent in other branches. After the power reduction request is responded to, for example, when the main DC-DC converter receives a command or information to start reducing power, the main DC-DC converter can control the DC-DC converter 220 corresponding to the second target battery cluster to perform safe current control.

[0171] In safe current control, after adjusting the current of the second target battery cluster to a safe current, the second target battery cluster is disconnected.

[0172] After disconnecting the second target battery cluster, the bypass switch 230 corresponding to the DC-DC converter 220 corresponding to the second target battery cluster is closed, and the DC-DC converter 220 switches to bypass operation.

[0173] In this embodiment of the application, if a battery cluster 210 is detected to have reached the cutoff condition, and the voltage regulation range of the DC-DC converter 220 corresponding to the battery cluster 210 does not meet the cutoff condition, the power of each battery cluster 210 is reduced first, and then the safe current is controlled. On the basis of ensuring the safety and stability of the system, the safe current operation and balance are effectively controlled.

[0174] Through the master-slave control logic in the different application scenarios described above, the technical effects that can be achieved include: 1) increasing the amount of charge received by each branch battery cluster 210 during charging. 2) increasing the amount of charge discharged by each branch battery cluster 210 during discharging. 3) coordinating the charging and discharging power among the branch battery clusters 210 to meet the total power requirements of the external energy storage converter. 4) providing balanced operating conditions for each branch battery cluster 210 in the entire system, ensuring the cell consistency of the battery clusters 210 within each branch.

[0175] Please refer to Figure 5 This is a first comparison diagram of the allowed capacity provided in the embodiments of this application. Figure 5 The maximum power usage time of the battery system 200 with DC-DC converter 220 (i.e., the maximum power usage time corresponding to the technical solution of this application embodiment) is compared with that of the battery system 200 without DC-DC converter 220. It can be seen that in the hard parallel system (battery system 200 without DC-DC converter 220), the time it takes for each cluster of batteries A, B, and C to be fully used or charged differs. When a cluster, such as battery cluster A, reaches the power reduction or cutoff condition, the entire parallel battery system 200 will also reduce its power or cut off. However, by adopting the technical solution provided in this application embodiment, the battery current can be adjusted by regulating the output voltage, so that each cluster reaches the power reduction or cutoff condition as simultaneously as possible, such as battery cluster A' and battery cluster B', thereby improving the maximum power usage time of the system.

[0176] Please refer to Figure 6 This is a second comparative diagram of the allowable capacity provided in the embodiments of this application. Figure 6 In a hard parallel system, when one cluster of batteries reaches the cutoff condition, the entire system must also be cut off. However, by adopting the technical solution provided in the embodiments of this application, one cluster can be kept off (or operating at 0 current) while the remaining clusters continue to operate normally. That is, the cutoff is phased, increasing the available capacity.

[0177] Therefore, the technical solution provided in this application embodiment can achieve the following functions in the above application scenarios: 1. Within the platform area, by reducing the charging current of a single cluster or increasing the discharging current of a single cluster, the capacity difference between clusters can be reduced, extending the maximum power usage time of the system. 2. In non-platform areas, a single cluster (a battery cluster in a fully charged / fully discharged state) is shut down, allowing other clusters to operate normally. The corresponding value includes: 1. Increasing the maximum power usage time of the energy storage system by 1000 (under a unit battery box configuration, more charging can be done when the electricity price is cheapest, and more discharging can be done when the price is most expensive). 2. When a single cluster is shut down, the remaining clusters can continue to be used (previously unavailable redundant capacity becomes available).

[0178] Based on the same inventive concept, please refer to Figure 7 This application also provides a battery management method, which is applied to... Figure 2 The battery system 200 shown includes a main DC-DC converter used therein. The battery management method includes:

[0179] Step 710: Obtain the battery status information of each battery cluster 210.

[0180] Step 720: Control each DC-DC converter 220 and each bypass switch 230 based on the battery status information of each battery cluster 210.

[0181] As an optional implementation, step 720 includes: determining the maximum and minimum voltages among the voltages of each battery cluster 210; determining the voltage difference between the maximum and minimum voltages; if the voltage difference is less than a preset voltage, controlling each bypass switch 230 to be closed; if the voltage difference is greater than the preset voltage, controlling each bypass switch 230 to be open; controlling the DC-DC converter 220 corresponding to the battery cluster 210 with the maximum voltage to stabilize the voltage of the battery cluster 210 with the maximum voltage to a first voltage, and controlling the DC-DC converters 220 corresponding to the battery cluster 210 other than the battery cluster 210 with the maximum voltage to stabilize the voltage of the battery cluster 210 other than the battery cluster 210 with the maximum voltage to a second voltage, wherein the second voltage is greater than the first voltage.

[0182] As an optional implementation, the battery management method further includes: controlling the respective control switches to be turned on while each battery cluster 210 is maintained at the corresponding voltage.

[0183] As an optional implementation, step 720 includes: controlling each bypass switch 230 to be in the open state; controlling the DC-DC converter 220 corresponding to the battery cluster 210 with the maximum voltage to stabilize the voltage of the battery cluster 210 with the maximum voltage to a first voltage; and controlling the DC-DC converter 220 corresponding to the battery cluster 210 other than the battery cluster 210 with the maximum voltage to stabilize the current of the battery cluster 210 other than the battery cluster 210 with the maximum voltage to a value greater than a first preset current.

[0184] As an optional implementation, the battery management method further includes: controlling each bypass switch 230 to be in an open state; controlling each DC-DC converter 220 to stabilize the current of the corresponding battery cluster 210 to be less than a first preset current; if the SOC of each battery cluster 210 is greater than the preset SOC, controlling each DC-DC converter 220 to stabilize the voltage of the corresponding battery cluster 210 to a preset voltage.

[0185] As an optional implementation, step 720 includes: determining the maximum and minimum SOC among the SOCs of each battery cluster 210; determining the SOC difference between the maximum and minimum SOCs; if the SOC difference is greater than a preset SOC value, controlling the bypass switch 230 corresponding to the DC-DC converter 220 corresponding to the first target battery cluster to be in an open state; the SOC of the first target battery cluster meets a preset SOC condition; controlling the DC-DC converter 220 corresponding to the first target battery cluster to stabilize the current of the first target battery cluster to a second preset current.

[0186] As an optional implementation, the battery management method further includes controlling each bypass switch 230 to be in a closed state when the SOC of each battery cluster 210 is the same as the average SOC of each battery cluster 210.

[0187] As an optional implementation, step 720 includes: if a battery cluster 210 is detected to meet a preset cutoff condition, and the voltage regulation range of the DC-DC converter 220 corresponding to the battery cluster 210 meets the cutoff condition, controlling the DC-DC converter 220 corresponding to the battery cluster 210 to stabilize the battery cluster 210 to operate at a safe current.

[0188] As an optional implementation, the battery management method further includes: if a battery cluster 210 is detected to meet a preset cutoff condition, and the voltage regulation range of the DC-DC converter 220 corresponding to the battery cluster 210 does not meet the cutoff condition, reducing the power of each battery cluster 210; controlling the DC-DC converter 220 corresponding to the second target battery cluster to adjust the current of the second target battery cluster to a safe current; wherein, if the battery system 200 is in a charging state, the second target battery cluster is a fully charged battery cluster 210, and if the battery system 200 is in a discharging state, the second target battery cluster is a fully discharged battery cluster 210; controlling the bypass switch 230 corresponding to the DC-DC converter 220 corresponding to the second target battery cluster to a closed state.

[0189] Since this battery management method corresponds to the master-slave control function of the master DC-DC converter, the implementation methods and technical effects of each step are the same as those of the aforementioned master-slave control process, and will not be repeated here.

[0190] Based on the same inventive concept, please refer to Figure 8 This application embodiment also provides a battery management device 800, which is connected to... Figure 7 The battery management method shown includes: an acquisition module 810 and a processing module 820.

[0191] The acquisition module 810 is used to acquire the battery status information of each battery cluster 210; the processing module 820 is used to control each DC-DC converter 220 and each bypass switch 230 based on the battery status information of each battery cluster 210.

[0192] As an optional implementation, the processing module 820 is specifically configured to: determine the maximum and minimum voltages among the voltages of each battery cluster 210; determine the voltage difference between the maximum and minimum voltages; if the voltage difference is less than a preset voltage, control each bypass switch 230 to be closed; if the voltage difference is greater than the preset voltage, control each bypass switch 230 to be open; control the DC-DC converter 220 corresponding to the battery cluster 210 with the maximum voltage to stabilize the voltage of the battery cluster 210 with the maximum voltage to a first voltage, and control the DC-DC converters 220 corresponding to the battery cluster 210 other than the battery cluster 210 with the maximum voltage to stabilize the voltage of the battery cluster 210 other than the battery cluster 210 with the maximum voltage to a second voltage, wherein the second voltage is greater than the first voltage.

[0193] As an optional implementation, the processing module 820 is also configured to: control the respective control switches to be turned on when each battery cluster 210 is maintained at the corresponding voltage.

[0194] As an optional implementation, the processing module 820 is specifically used to: control each bypass switch 230 to be in the open state; control the DC-DC converter 220 corresponding to the battery cluster 210 with the maximum voltage to stabilize the voltage of the battery cluster 210 with the maximum voltage to a first voltage; and control the DC-DC converter 220 corresponding to the battery cluster 210 other than the battery cluster 210 with the maximum voltage to stabilize the current of the battery cluster 210 other than the battery cluster 210 with the maximum voltage to a value greater than a first preset current.

[0195] As an optional implementation, the processing module 820 is also used to: control each bypass switch 230 to be in the open state; control each DC-DC converter 220 to stabilize the current of the corresponding battery cluster 210 to be less than a first preset current; if the SOC of each battery cluster 210 is greater than the preset SOC, control each DC-DC converter 220 to stabilize the voltage of the corresponding battery cluster 210 to a preset voltage.

[0196] As an optional implementation, the processing module 820 is specifically used to: determine the maximum and minimum SOC among the SOCs of each battery cluster 210; determine the SOC difference between the maximum and minimum SOCs; if the SOC difference is greater than a preset SOC value, control the bypass switch 230 corresponding to the DC-DC converter 220 corresponding to the first target battery cluster to be in an open state; the SOC of the first target battery cluster meets a preset SOC condition; control the DC-DC converter 220 corresponding to the first target battery cluster to stabilize the current of the first target battery cluster to a second preset current.

[0197] As an optional implementation, the processing module 820 is also used to: control each bypass switch 230 to be in a closed state when the SOC of each battery cluster 210 is the same as the average SOC of each battery cluster 210.

[0198] As an optional implementation, the processing module 820 is specifically used to: if a battery cluster 210 is detected to meet a preset cutoff condition, and the voltage regulation range of the DC-DC converter 220 corresponding to the battery cluster 210 meets the cutoff condition, control the DC-DC converter 220 corresponding to the battery cluster 210 to stabilize the battery cluster 210 to operate at a safe current.

[0199] As an optional implementation, the processing module 820 is further configured to: if a battery cluster 210 is detected to meet a preset cutoff condition, and the voltage regulation range of the DC-DC converter 220 corresponding to the battery cluster 210 does not meet the cutoff condition, reduce the power of each battery cluster 210; control the DC-DC converter 220 corresponding to the second target battery cluster to adjust the current of the second target battery cluster to a safe current; wherein, if the battery system 200 is in a charging state, the second target battery cluster is a fully charged battery cluster 210, and if the battery system 200 is in a discharging state, the second target battery cluster is a fully discharged battery cluster 210; control the bypass switch 230 corresponding to the DC-DC converter 220 corresponding to the second target battery cluster to be in a closed state.

[0200] Since the battery management device 800 corresponds to the battery management method, the implementation methods and technical effects of each functional module are the same as those of the aforementioned master-slave control process, and will not be repeated here.

[0201] This application also provides a computer-readable storage medium storing a computer program, which, when run by a computer, executes the battery management method described in the foregoing embodiments.

[0202] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0203] Furthermore, 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 units can be selected to achieve the purpose of this embodiment according to actual needs.

[0204] Furthermore, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0205] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A battery system characterized by, The battery system comprises: a plurality of parallel battery clusters, each battery cluster comprising: a plurality of battery groups; a plurality of DC-DC converters, an input end of each DC-DC converter being electrically connected to a power source, the plurality of DC-DC converters corresponding to the plurality of battery clusters one by one, and an output end of each corresponding DC-DC converter being connected in series to a corresponding battery cluster; the plurality of DC-DC converters comprising a master DC-DC converter; a plurality of bypass switches, the plurality of DC-DC converters corresponding to the plurality of bypass switches one by one, and an output end of each corresponding DC-DC converter being connected in parallel to a corresponding bypass switch; a battery state information acquisition unit, the battery state information acquisition unit being configured to acquire battery state information of each battery cluster and send the battery state information of each battery cluster to the master DC-DC converter; the master DC-DC converter being configured to control each DC-DC converter and each bypass switch based on the battery state information of each battery cluster; the battery state information comprising: voltages of each battery cluster before the battery system is powered on; the master DC-DC converter being specifically configured to: determine a maximum voltage and a minimum voltage in the voltages of each battery cluster; determine a voltage difference between the maximum voltage and the minimum voltage; if the voltage difference is less than a preset voltage, control each bypass switch to be in a closed state; if the voltage difference is greater than the preset voltage, control each bypass switch to be in an open state; 2. The battery system of claim 1, wherein, control a DC-DC converter corresponding to a battery cluster with the maximum voltage to stabilize a voltage of the battery cluster with the maximum voltage to a first voltage, and control DC-DC converters corresponding to battery clusters other than the battery cluster with the maximum voltage to stabilize voltages of the battery clusters other than the battery cluster with the maximum voltage to a second voltage, the second voltage being greater than the first voltage.

3. The battery system of claim 1, wherein, The plurality of DC-DC converters are pre-configured with codes, and the master DC-DC converter is a DC-DC converter corresponding to a maximum code or a minimum code in the plurality of codes.

4. The battery system of claim 1, wherein, The power source is one or more battery groups in any one battery cluster, and the input end of each DC-DC converter is connected in parallel to the power source. The battery system further comprises a plurality of control switches, the plurality of control switches corresponding to the plurality of battery clusters one by one, and each corresponding control switch being connected in series to a corresponding battery cluster, each control switch being in an open state before the battery system is powered on; the master DC-DC converter is further configured to:

5. The battery system of claim 1, wherein, control each control switch to be conductive when each battery cluster is maintained at a corresponding voltage. The battery state information comprises: voltages of each battery cluster when the battery system is charging, and the master DC-DC converter is further configured to: determine a maximum voltage in the voltages of each battery cluster; control each bypass switch to be in an open state; The maximum voltage corresponding to the battery cluster corresponding to the DC-DC converter is controlled to stabilize the voltage of the maximum voltage corresponding to the battery cluster to a first voltage, and the DC-DC converter corresponding to the battery cluster other than the maximum voltage corresponding to the battery cluster is controlled to stabilize the current of the battery cluster other than the maximum voltage corresponding to the battery cluster to be greater than the first preset current.

6. The battery system of claim 1, wherein, The battery state information includes: the voltage of each battery cluster and the SOC of each battery cluster when the battery system is discharging, and the main DC-DC converter is further used for: controlling the each bypass switch to be in an open state; controlling the each DC-DC converter to stabilize the current of the corresponding battery cluster to be less than the first preset current; if the SOC of each battery cluster is greater than the preset SOC, controlling the each DC-DC converter to stabilize the voltage of the corresponding battery cluster to be a preset voltage.

7. The battery system of claim 1, wherein, The battery state information includes: the SOC of each battery cluster after the battery system is powered on; and the main DC-DC converter is specifically used for: determining the maximum SOC and the minimum SOC in the SOC of each battery cluster; determining the SOC difference between the maximum SOC and the minimum SOC; if the SOC difference is greater than a preset SOC value, controlling the bypass switch corresponding to the DC-DC converter of the first target battery cluster to be in an open state; the SOC of the first target battery cluster satisfies a preset SOC condition; controlling the DC-DC converter corresponding to the first target battery cluster to stabilize the current of the first target battery cluster to a second preset current.

8. The battery system of claim 7, wherein, The main DC-DC converter is further used for: controlling the each bypass switch to be in a closed state when the SOC of each battery cluster is equal to the average value of the SOC of each battery cluster.

9. The battery system of claim 1, wherein, The battery state information further includes: whether each battery cluster satisfies a preset cutoff condition after the battery system is powered on; the each bypass switch is in an open state, and the main DC-DC converter is specifically used for: if it is detected that one battery cluster satisfies the preset cutoff condition and the voltage regulating range of the DC-DC converter corresponding to the battery cluster satisfies the cutoff condition, controlling the DC-DC converter corresponding to the battery cluster to stabilize the battery cluster to run at a safe current.

10. The battery system of claim 9, wherein, The main DC-DC converter is further used for: if it is detected that one battery cluster satisfies the preset cutoff condition and the voltage regulating range of the DC-DC converter corresponding to the battery cluster does not satisfy the cutoff condition, reducing the power of each battery cluster; controlling the DC-DC converter corresponding to the second target battery cluster to adjust the current of the second target battery cluster to a safe current; wherein, if the battery system is in a charging state, the second target battery cluster is a full-charged battery cluster, and if the battery system is in a discharging state, the second target battery cluster is a full-discharged battery cluster; controlling the bypass switch corresponding to the DC-DC converter corresponding to the second target battery cluster to be in a closed state.

11. A battery management method, characterized by, The battery management method is applied to the battery system in any one of claims 1-10, and the battery management method comprises: obtaining battery state information of each battery cluster; Control the DC-DC converters and the bypass switches based on the battery state information of the battery clusters.

12. The battery management method of claim 11, wherein, The battery state information includes voltages of the battery clusters before the battery system is powered on, and the control of the DC-DC converters and the bypass switches based on the battery state information of the battery clusters includes: determining a maximum voltage and a minimum voltage among the voltages of the battery clusters; determining a voltage difference between the maximum voltage and the minimum voltage; controlling the bypass switches to be in a closed state if the voltage difference is less than a preset voltage; controlling the bypass switches to be in an open state if the voltage difference is greater than the preset voltage; controlling the DC-DC converter corresponding to the battery cluster with the maximum voltage to stabilize the voltage of the battery cluster with the maximum voltage to a first voltage, and controlling the DC-DC converter corresponding to the battery cluster other than the battery cluster with the maximum voltage to stabilize the voltage of the battery cluster other than the battery cluster with the maximum voltage to a second voltage greater than the first voltage.

13. The battery management method of claim 12, wherein, The battery system further includes a plurality of control switches corresponding to the plurality of battery clusters, and the control switches and the battery clusters corresponding to each other are connected in series, and each control switch is in an open state before the battery system is powered on. The battery management method further includes: controlling the control switches to be conductive when the battery clusters are maintained at the corresponding voltages.

14. The battery management method of claim 11, wherein, The battery state information includes voltages of the battery clusters when the battery system is charging, and the control of the DC-DC converters and the bypass switches based on the battery state information of the battery clusters includes: determining a maximum voltage among the voltages of the battery clusters; controlling the bypass switches to be in an open state; controlling the DC-DC converter corresponding to the battery cluster with the maximum voltage to stabilize the voltage of the battery cluster with the maximum voltage to a first voltage, and controlling the DC-DC converter corresponding to the battery cluster other than the battery cluster with the maximum voltage to stabilize the current of the battery cluster other than the battery cluster with the maximum voltage to a first preset current.

15. The battery management method of claim 11, wherein, The battery state information includes voltages of the battery clusters and SOCs of the battery clusters when the battery system is discharging, and the battery management method further includes: controlling the bypass switches to be in an open state; controlling the DC-DC converters to stabilize the current of the corresponding battery cluster to be less than a first preset current; controlling the DC-DC converters to stabilize the voltage of the corresponding battery cluster to be a preset voltage if the SOCs of the battery clusters are all greater than a preset SOC.

16. The battery management method of claim 11, wherein, The battery state information includes SOCs of the battery clusters after the battery system is powered on, and the control of the DC-DC converters and the bypass switches based on the battery state information of the battery clusters includes: determining a maximum SOC and a minimum SOC among the SOCs of the battery clusters; determining an SOC difference between the maximum SOC and the minimum SOC; If the SOC difference is greater than a preset SOC value, a bypass switch corresponding to a DC-DC converter corresponding to the first target battery cluster is controlled to be in an open state; the SOC of the first target battery cluster satisfies a preset SOC condition; The DC-DC converter corresponding to the first target battery cluster is controlled to stabilize the current of the first target battery cluster to a second preset current.

17. The battery management method of claim 11, wherein, The battery management method further comprises: When the SOC of each battery cluster is equal to the average value of the SOCs of the battery clusters, the bypass switch is controlled to be in a closed state.

18. The battery management method of claim 11, wherein, After the battery system is powered on, whether each battery cluster satisfies a preset cutoff condition; The bypass switch is in an open state, and the battery management device controls the DC-DC converter and the bypass switch based on the battery state information of each battery cluster, which comprises: If it is detected that one battery cluster satisfies a preset cutoff condition, and the voltage regulation range of the DC-DC converter corresponding to the battery cluster satisfies the cutoff condition, the DC-DC converter corresponding to the battery cluster is controlled to stabilize the battery cluster to run at a safe current.

19. The battery management method of claim 18, wherein, The battery management method further comprises: If it is detected that one battery cluster satisfies a preset cutoff condition, and the voltage regulation range of the DC-DC converter corresponding to the battery cluster does not satisfy the cutoff condition, the power of each battery cluster is reduced; The DC-DC converter corresponding to the second target battery cluster is controlled to adjust the current of the second target battery cluster to a safe current; wherein, if the battery system is in a charging state, the second target battery cluster is a fully charged battery cluster, and if the battery system is in a discharging state, the second target battery cluster is a fully discharged battery cluster; The bypass switch corresponding to the DC-DC converter corresponding to the second target battery cluster is controlled to be in a closed state.

20. A battery management device, comprising: The battery management device applied to the battery system in any one of claims 1-10 comprises: An acquisition module configured to acquire battery state information of each battery cluster; A processing module configured to control the DC-DC converter and the bypass switch based on the battery state information of each battery cluster.

21. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, and the computer program is run by a computer to execute the battery management method in any one of claims 11-19.

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