CN117878514A

CN117878514A - Battery module, battery pack and energy storage system

Info

Publication number: CN117878514A
Application number: CN202311683851.6A
Authority: CN
Inventors: 李坪; 余士江; 魏冲
Original assignee: Huawei Digital Power Technologies Co Ltd
Current assignee: Huawei Digital Power Technologies Co Ltd
Priority date: 2023-12-08
Filing date: 2023-12-08
Publication date: 2024-04-12

Abstract

A battery module, a battery pack and an energy storage system. The battery module comprises a first protection unit, a first electric core and a second electric core; the first protection unit comprises a first breaking device, a first detection unit and a first controller; the first battery cell and the second battery cell are connected in series; the first breaking device is connected in series between the first battery cell and the second battery cell; the first detection unit is used for detecting first state information, and the first state information is used for indicating the state of the battery module; the first controller is used for controlling the first breaking device to be disconnected under the condition that the first state information indicates that the battery module is abnormal. The present application can provide effective battery protection.

Description

Battery module, battery pack and energy storage system

Technical Field

The application relates to the technical field of batteries, in particular to a battery module, a battery pack and an energy storage system.

Background

The battery pack is widely applied to the field of energy storage systems or electric automobiles. As a charged energy body, the battery pack may cause a safety failure during manufacturing, transportation, storage, installation, and operation. The safety faults mainly include two types, namely faults such as leakage or thermal runaway of the battery core caused by battery manufacturing defects, and safety risks caused by misuse of environments such as external overvoltage, overcurrent or overtemperature. Therefore, protection for the battery pack is required in system design.

Disclosure of Invention

The application provides a battery module, battery package and energy storage system that can effectively reduce the risk that high voltage breakdown electric core insulation appears between the electric core.

In a first aspect, the present application provides a battery module, including a first protection unit, a first cell, and a second cell; the first protection unit comprises a first breaking device, a first detection unit and a first controller; the first battery cell and the second battery cell are connected in series; the first breaking device is connected in series between the first battery cell and the second battery cell; the first detection unit is used for detecting first state information, and the first state information is used for indicating the state of the battery module; the first controller is used for controlling the first breaking device to be disconnected under the condition that the first state information indicates that the battery module is abnormal.

Alternatively, the first breaking device may be an explosion fuse, a contactor, a relay, a semiconductor switch, or the like, which is not limited in the present application.

In this scheme, through setting up protection element in the battery module to establish ties the device that breaks and set up between the electric core, can make in the battery module when the condition that the electric core appears unusual (e.g. overflow, excess temperature or electric leakage etc.), can cut off this device that breaks off fast, can effectively reduce the risk that high voltage breakdown electric core is insulating appears between the electric core in the battery module, realize battery module's protection.

In a possible implementation manner, the first battery cell and the second battery cell belong to a first battery cell group of the battery module; the battery module further comprises a second cell group, wherein the second cell group comprises a third cell and a fourth cell; the total voltage of the first cell group is smaller than or equal to the insulation voltage resistance of the first cell or the second cell, and the total voltage of the second cell group is smaller than or equal to the insulation voltage resistance of the third cell or the fourth cell; the first state information is used for indicating the state of the first cell group; the first controller is configured to control the first breaking device to be turned off when the first state information indicates that the first cell group is abnormal; the battery module further comprises a second protection unit; the second protection unit comprises a second separation device, a second detection unit and a second controller; the second breaking device is connected in series between the third cell and the fourth cell; the second detection unit is used for detecting second state information; the second state information is used for indicating the state of the second cell group; the second controller is configured to control the second breaking device to break when the second state information indicates that the second cell group is abnormal.

In this scheme, can set up a plurality of protection units in the battery module, the electric core grouping of different protection unit protection is different. And the total voltage of the battery cell groups is not more than the insulation withstand voltage of the battery cells in the groups. The design of the grouping ensures that the voltage applied to the battery cells by the external channels of the battery cells due to leakage and the like is not greater than the insulation voltage of the battery cells, namely the voltage applied to the battery cells due to the external channels can be reduced. In addition, the grouping design can also comprehensively and timely find out abnormal places, namely no matter which battery core in the battery module is abnormal, the corresponding protection units can detect and take protection measures, so that the risk of breakdown of the battery core is effectively reduced.

In another possible implementation manner, the first battery cells belong to a first battery cell group, and the second battery cells belong to a second battery cell group; the battery module further comprises a third cell group, wherein the third cell group comprises a fifth cell; the total voltage of the first cell group is smaller than or equal to the insulation voltage resistance of the first cell, the total voltage of the second cell group is smaller than or equal to the insulation voltage resistance of the second cell, and the total voltage of the third cell group is smaller than or equal to the insulation voltage resistance of the fifth cell; the first state information is used for indicating the state of the first cell group; the first controller is configured to control the first breaking device to be turned off when the first state information indicates that the first cell group is abnormal; the battery module further comprises a third protection unit, wherein the third protection unit comprises a third breaking device, a third detection unit and a third controller; the third breaking device is connected in series between the second battery cell and the fifth battery cell; the third detection unit is used for detecting third state information; the third status information is used for indicating the status of the second cell group; the third controller is configured to control the third breaking device to be turned off when the third state information indicates that the second cell group is abnormal.

In this scheme, the protection unit may be disposed between the cell groups. Similarly, the design of the grouping ensures that the voltage applied to the battery cells by the external channels of the battery cells due to leakage and the like is not greater than the insulation voltage of the battery cells, namely the voltage applied to the battery cells due to the external channels can be reduced. In addition, the grouping design can also comprehensively and timely find out abnormal places, namely no matter which battery core in the battery module is abnormal, the corresponding protection units can detect and take protection measures, so that the risk of breakdown of the battery core is effectively reduced.

In a possible implementation manner, the first detecting unit includes a current detecting unit, where the current detecting unit is configured to detect a current between the first battery cell and the second battery cell; the first controller is used for controlling the first breaking device to be disconnected under the condition that the current is different from the current at the positive electrode or the negative electrode of the battery module; or, the first controller is configured to control the first breaking device to be turned off when the current is greater than a first threshold.

In the scheme, when the current abnormality (such as overcurrent) occurs between the battery cells, the breaking device can be quickly broken, so that the protection of the battery module is realized. For example, when an external channel of the battery cell is formed between the battery cells in the battery module due to leakage, the external channel forms an additional current loop with the battery cell in the battery module (referred to as a battery cell a for short). The current flowing through the cell a includes a superposition of the current of the additional current loop and the current in the main circuit of the battery module (also the current at the positive or negative electrode of the above-mentioned battery module). Therefore, whether the current is abnormal can be judged by comparing the difference between the current flowing through the battery cell A and the current in the main circuit of the battery module or judging whether the current flowing through the battery cell A is larger than a preset threshold value, so that protection measures can be timely taken, and the protection of the battery module is realized.

In a possible implementation manner, the first detecting unit includes a temperature detecting unit, where the temperature detecting unit is configured to detect a temperature of the first battery cell or the second battery cell; the first controller is used for controlling the first breaking device to be disconnected under the condition that the temperature of the first battery cell or the second battery cell is larger than a second threshold value.

In the scheme, when the temperature abnormality (such as over-temperature) occurs between the battery cells, the breaking device can be quickly broken, so that the protection of the battery module is realized. Illustratively, the temperature of the cell is related to the current flowing through the cell, the greater the current flowing through the cell, the higher the temperature of the cell. Therefore, the current flowing through the battery cell a includes the superposition of the current of the extra current loop and the current in the main circuit of the battery module, that is, the current flowing through the battery cell a increases, and the temperature of the battery cell a also increases. Therefore, whether the temperature of the battery cell A is larger than a preset threshold value or not can be judged, and whether the temperature is abnormal or not can be judged, so that protection measures can be timely taken, and protection of the battery module is realized.

In one possible implementation manner, the first detection unit includes a leakage detection circuit, where the leakage detection circuit is connected to a ground line of the battery module and is configured to detect a current flowing through the ground line; the first controller is used for controlling the first breaking device to be disconnected under the condition that the current flowing through the grounding wire is larger than a third threshold value.

In this scheme, can be when the condition of electric leakage appears in the battery module, this breaking device of quick disconnection realizes battery module's protection. For example, if the external path is formed to form an additional current loop, if the ground line is connected to the current loop, the current flowing through the ground line increases. I.e. the current in the current loop flows to the ground line with the lower potential to cause leakage. Therefore, whether the current of the grounding wire is larger than a preset threshold value or not can be judged to judge whether the electric leakage is abnormal or not, so that protection measures can be timely taken, and the protection of the battery module is realized.

In a possible implementation manner, the first detection unit and the first controller are powered by one or more battery cells in the battery module. In this scheme, can be by the battery core in the battery module for the protection unit power supply to ensure that the protection unit is uninterrupted. Even under the condition that the battery system is not electrified due to storage or transportation, the abnormality detection and protection of the battery module can be effectively realized.

In a second aspect, the present application provides a battery PACK (PACK) comprising a battery module according to any one of the first aspects and a first battery management unit; the first battery management unit is used for collecting state information of the battery pack.

Optionally, the state information of the battery pack may include parameters such as main current, temperature or leakage current in the battery pack.

Alternatively, the first battery management unit may be a battery management unit (battery management unit, BMU). For example, the BMU may include a module battery management system (module battery management system, bms) and corresponding sampling control modules, communication modules, power supply modules, driving control circuits of switch bridge arms, etc. for implementing state detection and control of the battery modules in the battery pack.

In a possible implementation manner, the battery pack further includes a first auxiliary power source, and the first detection unit and the first controller in the battery module are powered by the first auxiliary power source. In this scheme, the protection unit in the battery module is supplied with power through auxiliary power supply to reduce the influence of battery module power supply to the battery module.

In a third aspect, the present application provides an energy storage system, where the energy storage system includes the battery pack of the second aspect and a second battery management unit; the second battery management unit is connected with the first battery management unit and the first controller included in the battery module; the second battery management unit is used for receiving the state information of the battery pack acquired by the first battery management unit; the second battery management unit is further configured to notify the first controller to control the first breaking device to be turned off when the status information indicates that the battery pack is abnormal.

Alternatively, the second battery management unit may be a battery control unit (battery controlunit, BCU). The BCU can be connected with the BMU in the battery pack through the control bus to perform real-time interaction of information with the battery pack, so that the battery pack can be monitored in real time and uniformly, flexible control of the energy storage system can be realized, and the applicability is high.

In a possible implementation manner, the energy storage system further includes a second auxiliary power source, and the first detection unit and the first controller are powered by the second auxiliary power source. In this scheme, the protection unit in the battery module is supplied with power through auxiliary power supply to reduce the influence of battery module power supply to the battery module.

In a fourth aspect, the present application provides a vehicle comprising a battery module as described in any one of the first aspects above.

The advantages of the second to fourth aspects may be found in the relevant description of the first aspect, and are not repeated here.

Drawings

Fig. 1 to 3 are schematic structural views of a conventional battery pack;

fig. 4 and fig. 5 are schematic structural views of a battery pack according to an embodiment of the present application;

fig. 5A, fig. 5B, and fig. 5C are schematic structural diagrams of an energy storage system according to an embodiment of the present application;

Fig. 6 to 9, 10A and 10B are schematic structural views of a battery module according to an embodiment of the present application;

fig. 11 is a schematic view illustrating connection between a battery module and a BMS according to an embodiment of the present application;

fig. 12 is a schematic diagram illustrating an additional current loop generated in the battery module according to the embodiment of the present application;

fig. 13 is a schematic diagram illustrating an additional current loop generated between battery packs according to an embodiment of the present application.

Detailed Description

In the embodiments of the present application, "plurality" means two or more. In the embodiment of the present application, "and/or" is used to describe the association relationship of the association object, and represents three relationships that may exist independently, for example, a and/or B may represent: a alone, B alone, or both a and B. Descriptions such as "at least one (or at least one) of a1, a2, … …, and an" used in the embodiments of the present application include a case where any one of a1, a2, … …, and an exists alone, and also include a case where any combination of any plurality of a1, a2, … …, and an exists alone; for example, the description of "at least one of a, b, and c" includes the case of a alone, b alone, c alone, a and b in combination, a and c in combination, b and c in combination, or abc in combination.

The terms "first," "second," and the like in this application are used to distinguish between identical or similar items that have substantially the same function and function, and it should be understood that there is no logical or chronological dependency between the "first," "second," and "nth" terms, nor is it limited to the number or order of execution. It will be further understood that, although the following description uses the terms first, second, etc. to describe various elements, these elements should not be limited by the terms. These terms are only used to distinguish one element from another element. The connections described in the embodiments of the present application refer to electrical connections.

In the various embodiments of the application, where no special description or logic conflict exists, the terms and/or descriptions between the various embodiments are consistent and may reference each other, and features of different embodiments may be combined to form new embodiments based on their inherent logic relationships.

The following is an exemplary description of embodiments of the present application with reference to the accompanying drawings.

The battery pack may include a plurality of battery cells therein. The plurality of cells may be connected in series. For example, referring to fig. 1, a schematic diagram of a battery pack is shown. In fig. 1, the battery pack includes three battery cells as an example. It can be seen that each cell includes a positive (+) and a negative (-). The battery cell 1, the battery cell 2 and the battery cell 3 are sequentially connected in series. BAT-represents the negative electrode of the battery pack, bat+ represents the positive electrode of the battery pack. It should be understood that the illustration in fig. 1 is merely exemplary and is not to be construed as limiting the embodiments of the present application.

Battery packs are widely used, but they can present safety risks during manufacturing, shipping, storage, installation, and operation. Therefore, the battery pack needs to be protected. In an existing protection scheme, for example, referring to fig. 2, a fuse is disposed at the negative electrode of the battery pack (for example, as shown in fig. 2 (a)), a fuse is disposed at the positive electrode of the battery pack (for example, as shown in fig. 2 (b)), or a fuse is disposed between the cells in the series-connected battery packs (for example, as shown in fig. 2 (c)). I.e., the fuse is disposed outside the battery pack. Under the condition that the main power of the battery pack is over-current or short-circuited to cause large current to pass through the safety fuse, the safety fuse is actively blown, so that the large current can be cut off, and the risk of thermal runaway or fire is avoided. However, this solution is not capable of preventing and controlling the risk of thermal runaway or fire due to high voltage occurring outside the battery pack, or leakage of electrolyte inside the battery pack caused by leakage of the battery cell itself, or leakage of electricity between the plurality of battery packs. Because the leakage does not cause large current to pass through the fuse, the fuse is not blown, and a protection dead zone exists.

In another existing protection scheme, a breaking device is added outside the battery pack. The breaking device is controlled by a battery management system (Battery Management System, BMS), for example as shown in fig. 3. When the BMS detects that faults such as overvoltage, overcurrent or overtemperature occur outside the battery pack, the breaking device is controlled to be disconnected so as to disconnect an energy channel outside the battery pack. And the external fault source or energy source is cut off, so that the safety of the battery pack is ensured. However, this solution cannot provide protection for the battery pack in a scenario where high voltage breakdown of the battery cell insulation occurs in the battery cell in the battery pack, or in a scenario where the BMS does not work, such as storage or transportation.

Illustratively, the high voltage breakdown cell insulation described above refers to: the voltage applied to the cell exceeds the maximum voltage that the cell can withstand, in which case the electrolyte inside the cell breaks down, through which a current path is formed, i.e. the cell insulation breaks down. The upper limit of the maximum voltage that the cell can withstand may be referred to as the dielectric withstand voltage of the cell. The insulation voltage may be, for example, insulation voltage of a terminal of the positive and negative electrodes of the cell and a housing. To facilitate an understanding of the high voltage breakdown cell insulation scenario, an exemplary description is provided below in connection with fig. 4 and 5.

For example, referring to fig. 4, the formation of a cell external path between cells inside a battery pack results in high voltage breakdown of the cell insulation. As shown in fig. 4, it is assumed that an external passage of the cell is generated between the cell 1 and the cell 3 in the battery pack due to dew condensation, leakage of electrolyte in the cell, cooling liquid (for example, cooling liquid for heating or radiating a battery in an automobile), or destruction of an insulating layer of the cell. The current of the external passage of the battery cell forms a loop through the positive electrode of the battery cell 1, the battery cell 2 in the battery pack and the negative electrode of the battery cell 3. This cell external path corresponds to a short circuit between the cell 1 and the cell 3, and the cell 2 is connected in series between the cell 1 and the cell 3, resulting in an increase in the voltage applied to the cell 1 and the cell 3. If the applied voltage is greater than the insulation voltage of the battery cells 1 and 3, insulation protection of the battery cells 1 and 3 may break down, so that thermal runaway or even fire risk occurs in the battery cells 1 and 3. And BMS mainly detects the outside unusual of battery package, can't in time detect the insulation breakdown condition between the inside electric core of battery package, therefore can't in time cut off the energy passageway, and then can't effectively protect the battery package.

Referring again to fig. 5, for example, the formation of a cell external path between two series connected battery packs results in high voltage breakdown of the cell insulation. As shown in fig. 5, it is assumed in the same way that a cell external passage is created between the cell 1 in the battery pack 1 and the cell 5 in the battery pack 2 due to dew water, leakage of electrolyte in the cell, coolant (e.g., coolant for heating or radiating a battery in an automobile), or destruction of an insulating layer of the cell. The current of the external passage of the battery cell forms a loop through the positive electrode of the battery cell 1, the battery cell 2 and the battery cell 3 in the battery pack 1, the battery cell 4 in the battery pack 2 and the negative electrode of the battery cell 5. This cell external path corresponds to a short circuit of the cells 1 and 5, and the cells 2, 3, and 4 are connected in series between the cells 1 and 5, resulting in an increase in the voltage applied to the cells 1 and 5. If the applied voltage is greater than the insulation voltage of the battery cells 1 and 5, insulation protection of the battery cells 1 and 5 may break down, so that thermal runaway or even fire risk occurs in the battery cells 1 and 5. Likewise, the BMS mainly detects the abnormality of the outside of the battery pack, and cannot timely detect the insulation breakdown condition between the battery cells in different battery packs, so that the energy channel cannot be timely cut off, and the battery pack cannot be effectively protected.

Based on the above description, in order to better realize the protection of the battery pack, the embodiment of the application provides a battery module, a battery pack and an energy storage system. The risk of high-voltage breakdown of battery cell insulation between battery cells can be effectively reduced, and protection of a battery module, a battery pack or an energy storage system is realized. In another possible implementation manner, effective protection can be provided for situations where the BMS such as warehouse or transportation is not working, so that protection cannot be provided for the battery module, the battery pack or the energy storage system.

Illustratively, the energy storage system provided by the embodiments of the present application relates to a multi-layer structure. The first layer is called an energy storage system or battery energy storage system, the second layer is called a battery PACK (PACK), and the third layer is called a battery module or energy storage module. The energy storage system may include one or more battery packs, which may include one or more battery modules. In another possible implementation, an intermediate layer may be further included between the energy storage system and the battery pack, and the intermediate layer may be, for example, an energy storage cell cluster or a battery cluster. For example, the energy storage system may include one or more battery clusters. The battery cluster may include a plurality of battery packs. It will be understood that different names of the same layer structure have the same meaning in the embodiments of the present application, and are used to refer to this specific layer structure, which is not distinguished in the embodiments of the present application. Furthermore, the energy storage system layering described herein is merely an example and is not limiting of embodiments of the present application. In a specific implementation, other layering manners may also be used, which are not limited by the embodiments of the present application.

The energy storage system provided in the embodiments of the present application is first described below by way of example. For example, referring to fig. 5A, a schematic diagram of one possible energy storage system configuration is shown. As shown in fig. 5A, the energy storage system may include a plurality of battery packs connected in series (n is an integer greater than 1 in fig. 5A as an example). Each battery pack may include a battery module 600 and a first battery management unit 601 therein.

A second battery management unit 602 is also included in the energy storage system. The second battery management unit 602 is connected to the first battery management unit 601 in each battery pack.

In a possible implementation, the energy storage system may further include a Direct Current (DC)/alternating current (alternating current, AC) converter, i.e., including a DC/AC converter 603. The DC/AC converter 603 may be connected to the series battery pack via a direct current bus. The DC/AC converter 603 may convert DC power to AC power and exchange energy with an AC power grid.

For example, the above detailed description of the battery module 600 may be exemplarily referred to the following related description of fig. 6 to 10B, which is not described in detail herein.

Illustratively, a battery pack 1 in an energy storage system is taken as an example. The first battery management unit 601 in the battery pack 1 may be used to collect state information of the battery pack 1. The state information of the battery pack 1 may include parameters such as a main current (e.g., a current at the positive electrode or the negative electrode of the battery pack 1), a temperature, or a leakage current in the battery pack 1, for example.

In one implementation, the first battery management unit 601 may be, for example, a battery management unit (battery management unit, BMU). For example, a modular battery management system (module battery management system, bms) and corresponding sampling control modules, communication modules, power modules, drive control circuits for switch legs, etc. may be included in the BMU for enabling status detection in the battery pack.

The second battery management unit 602 may be connected with the first battery management unit 601 in the battery pack through a control bus, for example. The second battery management unit 602 can interact with the first battery management unit 601 in each battery pack in real time to realize real-time and unified monitoring of each battery pack, thereby realizing flexible control of the energy storage system and having strong applicability. For example, the first battery management unit 601 may send the collected battery pack status information to the second battery management unit 602. The second battery management unit 602 may be configured to take corresponding protection measures in the case where the status information indicates that the battery pack is abnormal, and the specific implementation may be described in the following example of fig. 11, which is not described in detail herein.

The second battery management unit 602 may be, for example, a battery control unit (battery controlunit, BCU).

For example, the plurality of first and second battery management units 601 and 602 may be collectively referred to as a BMS of the energy storage system. It will be appreciated that in a specific implementation, the BMS in the energy storage system may be other implementations, and is not limited to the implementations described in the embodiments of the present application.

In one possible implementation, for example, as shown in fig. 5B, a DC/DC converter 604 may be further included in the energy storage system. The plurality of series connected battery packs may be coupled to a DC bus via a DC/DC converter 604. The DC/DC converter 604 can flexibly control the energy of the plurality of battery packs connected in series, and has high applicability. Illustratively, the DC/DC converter 604 may be a bidirectional DC/DC converter, and the circuit topology of the bidirectional DC/DC converter 604 may be an isolated circuit topology, a non-isolated circuit topology, or the like. The circuit topology of the bidirectional DC/DC converter can be selected from a boost circuit (boost circuit), a flying capacitor boost circuit (boost circuit boost circuit), a flying capacitor multi-level circuit (flying capacitor multilevel circuit), a positive-negative symmetrical three-level boost circuit (thread-level boost circuit), a four-tube boost-buck circuit (four-switch buck-boost circuit) and the like, and the circuit topology can be specifically determined according to the actual application scene requirement, and the application is not limited to the circuit topology.

Illustratively, as shown in fig. 5B, the second battery management unit 602 may be integrated in the DC/DC converter 604 to simplify the system structure of the energy storage system, and since the plurality of battery packs connected in series are typically installed in close proximity to the DC/DC converter 604, the integration of the second battery management unit 602 in the DC/DC converter 604 is advantageous for controlling the connection of the bus. Alternatively, in another possible implementation, the second battery management unit 602 and the DC/DC converter 604 may be each provided independently. The embodiments of the present application are not limited in this regard.

Illustratively, in another possible implementation, the plurality of battery packs connected in series may be one battery cluster, such as shown in fig. 5C. The battery cluster may be provided with a cluster control box 605 for unified control of the battery cluster. Devices such as a cluster-level fuse, a cluster-level insulation resistance detection device, a cluster-level switch and the like can be arranged in the cluster control box 605, so that management and protection of the battery cluster level are realized. As shown in fig. 5C, the battery cluster may be coupled to a dc bus through a cluster control box 605. The second battery management unit 602 may be integrated in the cluster control box 605 (as shown in fig. 5C), or may be provided independently, which is not limited by the embodiment of the present application.

It can be appreciated that the structure of the energy storage system shown in fig. 5A to 5C is only an example, and in a specific implementation, the energy storage structure may be any energy storage structure including the battery module or the battery pack provided in the embodiment of the present application, and the embodiment of the present application does not limit the structure of the specific energy storage system.

In one possible implementation manner, referring to fig. 6, a schematic structural diagram of a battery module according to an embodiment of the present application is shown.

The battery module 600 shown in fig. 6 may include a first protection unit 610 and a plurality of battery cells 620 (6 battery cells 620 are illustrated in fig. 6). The first protection unit 610 may include a first controller 611, a first detection unit 612, and a first breaking device 613. It can be seen that the plurality of cells 620 and the first breaking device 613 are connected in series. For example, the first breaking device 613 is connected in series between the cell 3 and the cell 4. It is understood that the first breaking device 613 can be connected in series between any adjacent two of the plurality of cells 620. For example, it may be connected in series between the battery cell 2 and the battery cell 3, or it may be connected in series between the battery cell 5 and the battery cell 6, etc., which are not illustrated here.

Illustratively, since the 6 cells 620 are connected in series. Then, it can also be said that the first breaking device 613 is connected in series between any two of the cells 1 to 6. For example, or alternatively, the first breaking device 613 is connected in series between the cell 1 and the cell 6. Alternatively, the first breaking device 613 is connected in series between the cell 1 and the cell 5. Alternatively, the first breaking device 613 is connected in series between the cell 2 and the cell 6. Alternatively, the first breaking device 613 is connected in series between the cell 2 and the cell 5, and so on.

For convenience of the following description, a path in which the plurality of battery cells 620 and the first breaking device 613 are connected in series is simply referred to as a first series path. The first series path may be connected by a power line, for example.

The first breaking device may be, for example, an explosion fuse, a contactor, a relay, or a semiconductor switch, etc., which is not limited by the embodiment of the present application. By way of example, the semiconductor switch may comprise, for example, an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT) or a metal-oxide semiconductor field effect transistor (Metal Oxide Semiconductor Field Effect Transistor, MOSFET) or the like. When the breaking device adopts a switch, the switch can be disconnected under the control of a control signal, so that a current path between the battery cells is disconnected. When the breaking device adopts the explosion fuse, the explosion fuse can be disconnected under the control of the control signal, so that a current path between the battery cells is disconnected. It should be understood that any device capable of performing breaking according to a control signal may be used as the controllable breaking device in the embodiment of the present application, and the controllable breaking device may be flexibly selected according to actual requirements, where the specific implementation of the breaking device is not limited in the embodiment of the present application.

The first controller 611 is connected to the first detecting unit 612 and the first breaking device 613. The first detection unit 612 may be configured to detect an abnormality of the first serial path and feed back the detection result to the first controller 611. If an abnormal condition occurs in the first serial path, the first controller 611 may control the first breaking device 613 to be disconnected to cut off the first serial path, thereby protecting the battery module 600. The first detection unit 612 may be used to detect the first status information, for example. The first status information is used to indicate the status of the first serial path. Specifically, the first state information may include, for example, a current flowing through the battery cell in the first serial path, a temperature of the battery cell, or a leakage current of the first serial path, which is not limited in the embodiment of the present application. The first detection unit 612 or the first controller 611 may determine that there is an abnormality in the battery module 600 through the first state information. For a specific analysis, see the description below, and will not be described in detail here.

In a possible implementation manner, the first detection unit 612 may include one or more of a first current detection unit 6121, a first temperature detection unit 6122, and a first leakage detection unit 6123, for example. Fig. 6 illustrates the inclusion of these three items.

The first current detection unit 6121 may be configured to detect a current of the first series path. For example, as shown in fig. 6, the first current detecting unit 6121 is connected to the first serial communication path through a signal line, and the current in the first serial path is fed back to the first current detecting unit 6121 through the connected signal line. It is understood that the position where the first current detection unit 6121 is connected to the first serial path through the signal line in fig. 6 is merely an example, and does not constitute a limitation of the embodiment of the present application. In a specific implementation, the first current detection unit 6121 may be connected to an arbitrary position on the first serial communication path through a signal line. The first current detection unit 6121 may be, for example, any circuit or sensor that can perform current detection, which is not limited in the embodiment of the present application.

The first temperature detecting unit 6122 may be configured to detect the temperature of the first series passage. For example, as shown in fig. 6, the first temperature detecting unit 6122 is connected to the battery cell 2 in the first series path through a signal line, and the temperature of the battery cell 2 (which may be used to represent the temperature of the first series path) is fed back to the first temperature detecting unit 6122 through the connected signal line. It is to be understood that the battery cells connected by the signal lines of the first temperature detecting unit 6122 in fig. 6 are only examples, and do not limit the embodiments of the present application. In a specific implementation, the first temperature detecting unit 6122 may be connected to any electrical core on the first serial communication path through a signal line. The first temperature detecting unit 6122 may be, for example, any circuit or sensor that can detect temperature, which is not limited in the embodiment of the present application.

The first leakage detection unit 6123 may be configured to detect a leakage condition of the first series path. For example, as shown in fig. 6, the first leakage detecting unit 6123 is connected to a ground line (see ground 1 of fig. 6) in the first series path through a signal line, and the current on the ground line is fed back to the first leakage detecting unit 6123 through the connected signal line. It should be understood that the connection positions of the ground wires in fig. 6 are only examples, and do not limit the embodiments of the present application. The first leakage detecting unit 6123 may be, for example, any circuit or sensor that can realize battery leakage detection, which is not limited in the embodiment of the present application.

In another possible implementation manner, the first detection unit 612 may further include other detection units such as a voltage detection unit. The voltage detection unit may be used for example to detect a voltage between any two points in the first series path described above. The above description about the first detection unit 612 is merely an example, and in a specific implementation, the first detection unit 612 may include more or fewer detection units, which is not limited in this embodiment of the present application.

In one possible implementation, for instance, as shown in fig. 7, the first protection unit 610 may further include an auxiliary power supply unit 614. The auxiliary power unit 614 may be used to connect an auxiliary power source or battery to the first protection unit 610 for powering the first controller 611 and the first detection unit 612. As shown in fig. 7, the auxiliary power supply unit 614 is connected to a first controller 611, and a power signal is input to the first controller 611 and then input to the first detection unit 612 through the first controller 611. Alternatively, the auxiliary power supply unit 614 may be directly connected to the first detection unit 612 without the first controller 611 for supplying power to the first detection unit 612, for example. The embodiment of the application does not limit the connection mode. The auxiliary power supply unit 614 may be, for example, a power circuit that may perform functions such as voltage stabilization, current stabilization, or power conversion, and the specific structure of the auxiliary power supply unit 614 is not limited in the embodiment of the present application.

The auxiliary power source connected to the first protection unit 610 may be, for example, an auxiliary power source in a battery pack to which the battery module 600 belongs. For example, assuming that the battery module 600 is the battery module 600 in the battery pack 1 shown in fig. 5A described above, the auxiliary power source may be the auxiliary power source in the battery pack 1. Alternatively, the auxiliary power source may be, for example, an auxiliary power source in an energy storage system to which the battery module 600 belongs, which may supply power to the BMS in the energy storage system. For example, assuming that the battery module 600 is any one of the battery modules 600 in the energy storage system shown in fig. 5A, the auxiliary power source may be an auxiliary power source in the energy storage system. And the auxiliary power supply may be used to power the first battery management unit 601 and/or the second battery management unit 602 in the energy storage system.

The battery connected to the first protection unit 610 may be, for example, one or more battery cells in the battery module 600.

Illustratively, as shown in fig. 7, the auxiliary power supply may be connected to the auxiliary power unit 614 through a diode D1. The battery may be connected to the auxiliary power unit 614 through a diode D2. The cathode of the diode D1 and the cathode of the diode D2 are connected together. The auxiliary power supply may be connected from the anode of diode D1. The battery may be accessed from the anode of diode D2.

For example, in a specific implementation, if the battery pack to which the battery module 600 belongs or the energy storage system to which the battery module belongs is in an operating state, the auxiliary power source may supply power to the first protection unit 610. If the battery pack to which the battery module 600 belongs or the energy storage system to which the battery module belongs is in a sleep state, the first protection unit 610 may be powered by the above-mentioned battery. For example, the voltage of the positive electrode of the auxiliary power input diode D1 may be set higher than the voltage of the positive electrode of the battery input diode D2. In this design, if the first battery management unit 601 is in an operating state, the voltage of the positive electrode of the auxiliary power input diode D1 is higher than the voltage of the positive electrode of the battery input diode D2, the auxiliary power supply preferentially supplies power to the first protection unit 610. If the first battery management unit 601 is in a sleep state, the voltage of the positive electrode of the auxiliary power input diode D1 is low or even zero, and the first protection unit 610 is powered by the connected battery.

Alternatively, in another possible implementation, if the auxiliary power source is an auxiliary power source in the energy storage system to which the battery module 600 belongs, a switch may be disposed between the auxiliary power unit 614 and the interface to which the auxiliary power source is connected and the interface to which the battery is connected. In this design, if the energy storage system is in an operating state (i.e., the BMS in the energy storage system is also in an operating state), the BMS may control the switch to close and conduct the interface between the auxiliary power supply unit 614 and the auxiliary power supply, so that the auxiliary power supply supplies power to the first protection unit 610. If the BMS is in a sleep state, the BMS may control the switch to close and turn on the auxiliary power unit 614 and the battery-connected interface before the sleep state, so that the connected battery supplies power to the first protection unit 610. For example, in one possible implementation, based on the above description, the first protection unit 610 may determine whether the BMS is in an active state or a sleep state according to an object of power supply. Specifically, if the first protection unit 610 detects that the power signal is from the interface to which the auxiliary power is connected, it can be known that the BMS is in an operating state. If the first protection unit 610 detects that the power signal is from the battery-accessed interface, it can be known that the BMS is in a sleep state.

In the above scheme, if the battery pack to which the battery module 600 belongs or the energy storage system to which the battery module belongs works, the auxiliary power supply supplies power to the protection unit in the battery pack, so as to reduce the influence of the power supply of the battery module on the battery module; if the battery pack or the energy storage system to which the battery module 600 belongs is dormant, the battery module may supply power to the first protection unit 610, so as to ensure that the detection and protection of the abnormality of the battery module can be also realized when the battery pack or the energy storage system to which the battery module 600 belongs is dormant. In addition, the power of the battery module is reused to supply power to the first protection unit 610, and the cost is saved.

In another possible implementation manner, the first protection unit 610 may also be powered by an additional auxiliary power source, which is not limited in this embodiment of the present application.

In one possible implementation, for example, as can be seen in fig. 8, the battery module 600 may further include a second protection unit 640 and one or more battery cells 620 (3 battery cells 620, from battery cell 7 to battery cell 9, are illustrated in fig. 8). The second protection unit 640 may include a second controller 641, a second detection unit 642, and a second breaking device 643. It can be seen that the plurality of cells 620 and the second breaking device 643 are connected in series. For example, the second breaking device 643 is connected in series between the cell 6 and the cell 7. It is understood that the second breaking device 643 may be connected in series between any adjacent two of the cells 4 to 9. For example, it may be connected in series between the battery cell 7 and the battery cell 8, etc., which are not illustrated here.

Illustratively, the battery cells 620 in the battery module 600 are connected in series. Then, it can also be said that the second breaking device 643 is connected in series between any two of the cells 4 to 9. For example, or alternatively, the second breaking device 643 is connected in series between the cell 4 and the cell 9. Alternatively, the second break device 643 is connected in series between cell 1 and cell 8. Alternatively, the second breaking device 643 is connected in series between the cell 5 and the cell 9. Alternatively, the second break device 643 is connected in series between the cell 5 and the cell 8, and so on.

For convenience of the following description, the path in which the cells 4 to 9 and the second breaking device 643 are connected in series is simply referred to as a second series path.

The second controller 641 is connected to the second detecting unit 642 and the second dividing device 643. The second detecting unit 642 may be configured to detect an abnormality of the second serial path and feed back a detection result to the second controller 641. If an abnormal condition occurs in the second serial path, the second controller 641 can control the second breaking device 643 to break off so as to cut off the second serial path and protect the battery module 600. The second detecting unit 642 may be used to detect the second status information, for example. The second status information is used to indicate the status of the second serial path. Specifically, the second state information may include, for example, a current flowing through the battery cell in the second serial path, a temperature of the battery cell, or a leakage current of the second serial path, which is not limited in the embodiment of the present application. The second detecting unit 642 or the second controller 641 may determine that there is an abnormality in the second series path through the second state information. The process of this analysis is the same as the analysis process of determining the presence of an abnormality in the first serial path.

In a possible implementation manner, the second detecting unit 642 may include one or more of a second current detecting unit 6421, a second temperature detecting unit 6422, and a second leakage detecting unit 6423, for example. Fig. 8 illustrates the inclusion of these three items.

The second current detection unit 6421 may be configured to detect a current of the second series path. For example, as shown in fig. 8, the second current detection unit 6421 is connected to the second serial communication path through a signal line, and the current in the second serial path is fed back to the second current detection unit 6421 through the connected signal line. It is to be understood that the position where the second current detection unit 6421 is connected to the second serial path through the signal line in fig. 8 is merely an example, and does not constitute a limitation of the embodiment of the present application. In a specific implementation, the second current detection unit 6421 may be connected to any position on the second serial communication path through a signal line. The second current detection unit 6421 may be, for example, any circuit or sensor that can perform current detection, which is not limited by the embodiment of the present application.

The second temperature detection unit 6422 may be configured to detect a temperature of the second series path. For example, as shown in fig. 8, the second temperature detection unit 6422 is connected to the battery cell 6 in the second series path through a signal line, and the temperature of the battery cell 6 (which may be used to represent the temperature of the second series path) is fed back to the second temperature detection unit 6422 through the connected signal line. It is to be understood that the battery cells connected to the second temperature detecting unit 6422 through the signal lines in fig. 8 are only examples, and are not limited to the embodiments of the present application. In a specific implementation, the second temperature detection unit 6422 may be connected to any of the electrical cores on the second serial communication path through a signal line. The second temperature detection unit 6422 may be, for example, any circuit or sensor that can detect temperature, and the embodiment of the present application is not limited thereto.

The second leakage detection unit 6423 may be configured to detect leakage of the second series path. For example, as shown in fig. 8, the second leakage detection unit 6423 is connected to a ground line (see ground 2) in the second series path through a signal line, and the current on the ground line is fed back to the second leakage detection unit 6423 through the connected signal line. It should be understood that the connection positions of the ground lines in fig. 8 are only examples, and do not limit the embodiments of the present application. The second leakage detection unit 6423 may be, for example, any circuit or sensor that can realize battery leakage detection, which is not limited by the embodiment of the present application. The ground 2 may be connected to the ground 1, for example, or may be separate.

In another possible implementation manner, the second detecting unit 642 may further include other detecting units such as a voltage detecting unit. The voltage detection unit may be used for example to detect a voltage between any two points in the second series path described above. The above description of the second detecting unit 642 is merely an example, and in a specific implementation, the second detecting unit 642 may include more or fewer detecting units, which is not limited in this embodiment of the present application.

In a possible implementation manner, as shown in fig. 8, the second protection unit 640 may further include an auxiliary power supply unit 644. The auxiliary power supply unit 644 may be used to connect an auxiliary power source or battery into the second protection unit 640 for supplying power to the second controller 641 and the second detection unit 642. The specific implementation may refer to the related description about the auxiliary power unit 614, which is not repeated here. In addition, the auxiliary power supply may be connected to the auxiliary power supply unit 644 through a diode D3. The battery may be connected to the auxiliary power supply unit 644 through a diode D4. Specific implementation may refer to the related description of the diode D1 and the diode D2, which are not repeated herein.

In a possible implementation, see for example fig. 9. The battery module 600 may further include more battery cells 620 connected in series, and more protection units (e.g., a third protection unit 650, a fourth protection unit 660, and a fifth protection unit 670 exemplarily shown in fig. 9). The description of the third protection unit 650 and the fifth protection unit 670 may refer to the description of the first protection unit 610, and the description of the fourth protection unit 660 may refer to the description of the second protection unit 640, which is not repeated herein.

As can be seen from fig. 8 and 9 described above, a plurality of protection units may be provided in the battery module, with different protection units protecting different groups of cells. This is equivalent to grouping (or partitioning) the plurality of battery cells 620 in the battery module, and the battery cells 620 included in different groupings may overlap or not overlap. Illustratively, the grouping may be based on the voltage between the positive and negative poles of the cells 620, the voltage across the series path (e.g., the first series path or the second series path described above), and the dielectric withstand voltage of the cells 620. Specifically, the voltage across the series path cannot be greater than the dielectric withstand voltage of the cell 620. If the voltage across the series circuit is greater than the dielectric withstand voltage of the cell 620, then the maximum voltage applied to the cells across the series circuit is the voltage across the series circuit if a cell external path (see, for example, the cell external path shown in fig. 4 or 5) is created between the cells across the series circuit. Since the voltage across the series circuit is greater than the dielectric withstand voltage of the cell 620, the insulation of the cell at both ends will break down, risking thermal runaway or even fire (see for example the previous description of fig. 4 or 5). For ease of understanding, the first series path is illustrated below.

For example, in the first series path, the voltage of the battery cell 620 is assumed to be a volts (V), and the withstand voltage of the battery cell 620 is assumed to be b volts. Then, when calculating the number of cells of each of the cell groups, the number of cells of the group can be calculated by dividing b by a, i.e., b/a. Assuming b/a=6, 6 or sequentially series connected cells may be divided into one group, as shown in the first series path. Alternatively, the number of cells of one cell group may be greater than 1 and less than 6. The voltage across the first series path is the voltage across the series of cells 1 to 6. The voltage across the first series path is 6a volts. The 6a is not greater than the insulation withstand voltage b of the cell 620. Thus, a cell external path is generated between the cell 1 and the cell 6, and the maximum voltage applied to the cell 1 and the cell 6 is 6a. The insulation withstand voltage b is not exceeded, and thus no breakdown of the cell insulation occurs. If b/a=5, the voltage 6a v across the first series path is greater than the insulation withstand voltage b (b=5a). In this case, if a cell external path is generated between the cell 1 and the cell 6, the maximum voltage applied to the cell 1 and the cell 6 is 6a. Exceeding the insulation withstand voltage b, breakdown of the cell insulation occurs.

In another possible implementation, reference may be made to fig. 10A and 10B, which schematically illustrate two possible implementations of the cell grouping. For example, as shown in fig. 10A, the protection units are disposed between the cell groups. Illustratively, four groups of cells are shown schematically in fig. 10A. The first protection unit 610 is disposed between the first cell group and the second cell group, that is, the first breaking device 613 included in the first protection unit 610 is connected in series between the first cell group and the second cell group. The second protection unit 640 is disposed between the second and third cell groups, that is, the second protection unit 640 includes a second breaking device 643 connected in series between the second and third cell groups. The setting positions of the rest protection units are the same and are not repeated.

For example, as shown in fig. 10B, the protection units are disposed within the cell groupings. Illustratively, three cell groupings are shown schematically in fig. 10B. The first protection unit 610 is disposed in the first cell group, that is, the first breaking device 613 included in the first protection unit 610 is connected in series between the cells of the first cell group. The second protection unit 640 is arranged in the second cell group, i.e. the second protection unit 640 comprises a second breaking device 643 connected in series between the cells of the second cell group. The setting positions of the rest protection units are the same and are not repeated.

Illustratively, in fig. 10A and 10B, the first detecting unit 612 in the first protection unit 610 may be configured to detect the state information of the first cell packet; the first controller 611 is configured to control the first breaking device 613 to be turned off in case the state information indicates that the first cell grouping is abnormal. The second detecting unit 642 in the second protecting unit 640 may be configured to detect status information of the second cell packet; the second controller 641 is configured to control the second breaking device 643 to break if the status information indicates that the second cell grouping is abnormal.

It is to be understood that the above grouping is merely exemplary and is not to be construed as limiting the embodiments of the present application. In addition, the number of the cells included in each cell group may be determined according to the voltage of the cells and the insulation voltage resistance of the cells, which is not limited in the embodiment of the present application.

In summary, according to the above-mentioned scheme of cell grouping protection, even if a housing path is formed between two cells in a grouping, the maximum voltage applied to the cells will not exceed the cell insulation voltage, so that the risk of breakdown of the cell insulation can be reduced, and the protection of the battery can be effectively realized. In addition, the grouping can also find the abnormal place comprehensively and timely and take protective measures.

In a possible implementation manner, the controller included in the protection unit of the battery module 600 may be further connected to the second battery management unit 602 in the energy storage system. For example, as shown in fig. 11, fig. 11 illustrates an example in which the first controller 611 of the first protection unit 610 of the battery module 600 is connected to the second battery management unit 602. Further, the first battery management unit 601 shown in fig. 11 is a first battery management unit in a battery pack to which the battery module 600 belongs. The first battery management unit 601 may collect status information of a battery pack to which the battery module 600 belongs. The status information may include, for example, information of current, temperature, or leakage conditions in the battery pack.

For example, in a specific implementation, the first battery management unit 601 may send the collected state information of the battery pack to the second battery management unit 602. The second battery management unit 602 may inform the first controller 611 to control the first breaking device 613 to be turned off in case the state information indicates that the battery pack has an abnormality. Illustratively, the case where the battery pack is abnormal may include, for example, one or more of the following: the main current (e.g., current at the positive or negative electrode of the battery pack, etc.) in the battery pack detected by the first battery management unit 601 is greater than a preset current threshold; the temperature in the battery pack detected by the first battery management unit 601 is greater than a preset temperature threshold; the leakage current in the battery pack detected by the first battery management unit 601 is greater than a preset leakage current threshold value, and so on. The embodiment of the application does not limit the abnormal condition of the battery pack.

For example, the first protection unit 610 may be operated or stopped when the first battery management unit 601 and the second battery management unit 602 are in a normal operation state. If the first protection unit 610 is also operated, the status information in the first serial path (or the first cell group) can be detected, which will be described later with reference to fig. 12. The first controller 611 also controls the first breaking device 613 to be turned off if the detected state information indicates the occurrence of an abnormality.

Illustratively, if the first battery management unit 601 and the second battery management unit 602 are in a sleep state. For example, in the case where the energy storage system is stored or transported, the first battery management unit 601 and the second battery management unit 602 are generally in a dormant state in order to reduce the consumption of the remaining power of the batteries in the energy storage system by the first battery management unit 601 and the second battery management unit 602. The first battery management unit 601 and the second battery management unit 602 can no longer realize the detection of the state information in the battery module 600. In this case, the first protection unit 610 may normally detect the state information in the first serial path (or the first cell group). The first controller 611 may control the first breaking device 613 to be turned off if the detected state information indicates the occurrence of an abnormality.

In the above-described scheme, when the first battery management unit 601 and the second battery management unit 602 (collectively referred to as a BMS) operate, the BMS and/or the above-described first protection unit 610 may detect state information of the battery module 600. The first protection unit 610 may also detect state information of the battery module 600 while the BMS is dormant. Thereby realizing the overall and effective protection of the battery module 600.

The foregoing mainly describes the structures of the energy storage system, the battery module and the relationship between them provided in the embodiments of the present application. The following describes the specific implementation process of the battery protection method provided in the embodiment of the present application in an exemplary manner in connection with the structure of the energy storage system, the battery module, and the relationship therebetween. The first protection unit 610 is described as an example.

For example, in a specific implementation, if the first detecting unit 612 includes a current detecting unit (e.g., the first current detecting unit 6121), the current abnormality of the first serial path, or the current abnormality of the first cell group, may be detected by the first current detecting unit 6121. For ease of understanding, see, for example, fig. 12. In fig. 12, a cell external passage is generated between the first cell (cell 1) and the second cell (cell 6) due to dew condensation, leakage of electrolyte, leakage of coolant, dielectric breakdown, or the like. Due to the presence of this external path of the cells, an additional current loop is formed between cell 1, cell 2, cell 3, first breaking device 613, cell 4, cell 5 and cell 6 (see dashed lines in fig. 12). Resulting in a change in current in the first series path (or first cell grouping).

For example, if the energy storage system to which the battery module 600 belongs is in an active state, i.e., the battery module 600 and the BMS of the energy storage system are in an active state, the battery module 600 is supplying power to the load, and current is naturally present in the first serial path (or the first cell group). If the external current path between cell 1 and cell 2 forms the additional current loop, the current flowing through the first series path (or first cell grouping) will change. The first current detection unit 6121 described above can detect such a change in current. For example, the first current detection unit 6121 may compare the detected current of the first series path (or the first cell group) with the current at BAT-, the current at BAT+, or the current between BAT-and BAT+. Because of the series connection, the current of the first series path is the same as the current at BAT-, BAT+ and between BAT-and BAT+ if no other current loop is present. Based on this, if the comparison finds that the currents are different, it indicates that the current of the first series path is abnormal. The first current detection unit 6121 may feed back the comparison result to the first controller 611. The first controller 611 may control the first breaking device 613 to be turned off.

In another implementation, the current at BAT-, BAT+ or the current between BAT-and BAT+ may be detected by the BMS in the energy storage system to which the battery module 600 belongs. The first current detection unit 6121 may detect the current of the first series path (or the first cell group). Then, the BMS and the first current detection unit 6121 respectively transmit the detected current to the first controller 611. The received current is compared by the first controller 611 and the first breaking device 613 is controlled to be turned off in case of current abnormality. In one possible implementation, the current at BAT-, current at bat+, or current between BAT-and bat+ may be detected, for example, by the first battery management unit 601 in the battery pack to which the battery module 600 belongs. The detected current is then transmitted to the second battery management unit 602. The detected current is then transmitted to the first controller 611 by the second battery management unit 602. It is to be understood that the description herein of the detection of the current at BAT-, BAT+ or between BAT-and BAT+ is only an example and does not constitute a limitation of the embodiments of the present application. For example, if the energy storage system to which the battery module 600 belongs is not powered on, the BMS is in a sleep state. Normally, the first series path (or first cell group) at this time is currentless. However, if the above-described external current path is formed between the cell 1 and the cell 2, and the above-described additional current loop is formed, current flows through the first series path. The first current detection unit 6121 described above can detect such a change in current. And feeds back the detection result to the first controller 611. The first controller 611 may control the first breaking device 613 to be turned off. For example, the first current detection unit 6121 detects a current, and determines that the detected current is greater than zero. Then, the first current detection unit 6121 may feed back a detection result that the current is greater than zero to the first controller 611. The first controller 611 may control the first breaking device 613 to be turned off. Or, for example, the first current detecting unit 6121 detects a current and feeds back the detected current to the first controller 611. The first controller 611 determines that the detected current is greater than zero, and then controls the first breaking device 613 to be turned off.

In another possible implementation, a current threshold may be preset regardless of whether the energy storage system to which the battery module 600 belongs is in the powered-on operation state, and regardless of whether the abnormality is determined by the first current detection unit 6121 or the abnormality is determined by the first controller 611. If the current detected by the first current detecting unit 6121 is greater than the current threshold, it indicates that the current is abnormal, and the first controller 611 may control the first breaking device 613 to be turned off.

Illustratively, in a specific implementation, if the first detection unit includes a temperature detection unit (e.g., the first temperature detection unit 6122 described above). Then, the temperature abnormality of the first series path (or the first cell group) may be detected by the temperature detection unit. For example, still described exemplarily in connection with fig. 12 above. The additional current loop is formed if the external path of the battery cell occurs between the battery cell 1 and the battery cell 6 regardless of whether the BMS is in an operating state or a sleep state. The current flowing in the first series path (or first cell grouping) increases compared to when no path outside the cell is present. The increase in current causes the temperature of the cells in the first series path to increase. The first temperature detection unit 6122 may detect such a change in temperature. And feeds back the detection result to the first controller 611. The first controller 611 may control the first breaking device 613 to be turned off.

For example, a temperature threshold may be preset. The first controller 611 may control the first breaking device 613 to be turned off if the temperature detected by the first temperature detecting unit 6122 is greater than the temperature threshold. For example, the first temperature detection unit 6122 detects a temperature, and determines that the detected temperature is greater than the temperature threshold. Then, the first temperature detection unit 6122 may feed back a detection result that the temperature is greater than the temperature threshold value to the first controller 611. The first controller 611 may control the first breaking device 613 to be turned off. Or, for example, the first temperature detecting unit 6122 detects a temperature and feeds back the detected temperature to the first controller 611. The first controller 611 determines that the detected temperature is greater than the temperature threshold value, and then controls the first breaking device 613 to be turned off.

Alternatively, in another possible implementation, a temperature change threshold may be preset. If the difference between the temperature after the change and the temperature before the change is greater than the preset temperature change threshold, the first controller 611 may control the first breaking device 613 to be turned off. The specific implementation is the same as the description of the temperature threshold in the previous section, and the description is not repeated.

Illustratively, in a specific implementation, if the first detection unit includes a leakage detection unit (e.g., the first leakage detection unit 6123). Then, the leakage condition of the first series path (or the first cell group) may be detected by the temperature detection unit. If leakage occurs in the first series path (or first cell group), the current flowing through the ground line increases. The first leakage detection unit 6123 can detect such a change in current. And feeds back the detection result to the first controller 611. The first controller 611 may control the first breaking device 613 to be turned off. For example, a leakage current threshold may be preset. If the leakage current detected by the first leakage detecting unit 6123 is greater than the leakage current threshold, the first controller 611 may control the first breaking device 613 to be turned off. For example, the first leakage detecting unit 6123 detects a leakage current, and determines that the detected leakage current is larger than the leakage current threshold. Then, the first leakage detection unit 6123 may feed back a detection result that the leakage current is greater than the leakage current threshold value to the first controller 611. The first controller 611 may control the first breaking device 613 to be turned off. Alternatively, for example, the first leakage detecting unit 6123 detects a leakage current and feeds back the leakage current to the first controller 611. The first controller 611 determines that the detected leakage current is greater than the leakage current threshold value, and then controls the first breaking device 613 to be turned off.

It should be understood that the above description mainly takes the first protection unit 610 in the battery module 600 as an example. In a specific implementation, other protection units in the battery module 600 may also implement a response function, which is not described herein.

In one possible implementation, the embodiment of the application can also realize protection when abnormal conditions occur between the battery packs connected in series. An exemplary description is provided below in connection with fig. 13.

In fig. 13, two battery packs connected in series in a battery module are taken as an example. Illustratively, it is assumed in fig. 13 that the protection unit is packaged together with the battery cells in a battery pack. The number of cells in series and the number of protection units in the battery pack are merely examples, and more or fewer cells and protection units may be included in a particular implementation. As shown in fig. 13, the battery pack 1 includes a protection unit 11, a protection unit 12, and a protection unit 13, and a plurality of battery cells connected in series. Likewise, the battery pack 2 includes a protection unit 21, a protection unit 22, and a protection unit 23, and a plurality of battery cells connected in series. The protection unit 11, the protection unit 13, the protection unit 21, and the protection unit 23 may exemplarily be referred to the first protection unit 610 described above. The protection unit 12 and the protection unit 22 may exemplarily be referred to the second protection unit 640 described above.

For example, in fig. 13 described above, it is assumed that the cell a in the battery pack 1 and the cell b in the battery pack 2 generate a cell external path due to condensation water, leakage of electrolyte, leakage of coolant, dielectric breakdown, or the like. Due to the presence of this external path of the cell, an additional current loop is formed (see dashed line in fig. 13). The current in the paths in the battery pack 1 and the battery pack 2 through which the current loop passes changes. And the protection unit 12, the protection unit 13, the protection unit 21, and the protection unit 22 in the path can detect the abnormality of the current in the path and disconnect the respective breaking devices based on the abnormality. The specific implementation of each protection unit may be referred to the related description in fig. 12, which is not repeated here.

In fig. 13, if the protection unit is not provided in the path, after the external path of the cell is generated, the maximum voltage applied to the cell a and the cell b may exceed the insulation voltage of the two cells, so that the insulation of the two cells may be broken down, and thermal runaway and even fire may occur. Therefore, through setting up above-mentioned protection cell in the battery package, this application embodiment can reduce the risk that causes thermal runaway and even fires because of producing electric core outside passageway between the battery package, ensures battery module's safety.

To sum up, according to the embodiment of the application, the protection unit is arranged in the battery module, and the breaking devices are arranged between the battery cells in series, so that the breaking devices can be rapidly broken when abnormality (such as overcurrent, overtemperature or electric leakage and the like) occurs between the battery cells, and the protection of the battery module is realized. In this scheme, to the scene that high voltage breakdown electric core is insulating appears at the electric core, perhaps to storage or transportation etc. BMS system does not work and leads to unable scene that provides the protection to the battery module, homoenergetic provides effectual battery module protection.

It should be understood that, in the embodiments of the present application, the sequence number of each process does not mean that the execution sequence of each process should be determined by the function and the internal logic of each process, and should not constitute any limitation on the implementation process of the embodiments of the present application.

It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It should be further understood that reference throughout this specification to "one embodiment," "an embodiment," "one possible implementation," means that a particular feature, structure, or characteristic described in connection with the embodiment or implementation is included in at least one embodiment of the present application. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment," "one possible implementation" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. The battery module is characterized by comprising a first protection unit, a first electric core and a second electric core; the first protection unit comprises a first breaking device, a first detection unit and a first controller;

The first battery cell and the second battery cell are connected in series;

the first breaking device is connected in series between the first battery cell and the second battery cell;

the first detection unit is used for detecting first state information, and the first state information is used for indicating the state of the battery module;

the first controller is used for controlling the first breaking device to be disconnected under the condition that the first state information indicates that the battery module is abnormal.

2. The battery module of claim 1, wherein the first cell and the second cell belong to a first cell group of the battery module; the battery module further comprises a second cell group, wherein the second cell group comprises a third cell and a fourth cell; the total voltage of the first battery cell group is smaller than or equal to the insulation voltage resistance of the first battery cell or the second battery cell, and the total voltage of the second battery cell group is smaller than or equal to the insulation voltage resistance of the third battery cell or the fourth battery cell;

the first state information is used for indicating the state of the first cell group;

the first controller is used for controlling the first breaking device to be disconnected under the condition that the first state information indicates that the first battery cell grouping is abnormal;

The battery module further comprises a second protection unit; the second protection unit comprises a second separation device, a second detection unit and a second controller;

the second breaking device is connected in series between the third cell and the fourth cell;

the second detection unit is used for detecting second state information; the second state information is used for indicating the state of the second cell group;

the second controller is configured to control the second breaking device to break if the second state information indicates that the second cell grouping is abnormal.

3. The battery module of claim 1, wherein the first cells belong to a first cell group and the second cells belong to a second cell group; the battery module further comprises a third cell group, wherein the third cell group comprises a fifth cell; the total voltage of the first electric core group is smaller than or equal to the insulation voltage resistance of the first electric core, the total voltage of the second electric core group is smaller than or equal to the insulation voltage resistance of the second electric core, and the total voltage of the third electric core group is smaller than or equal to the insulation voltage resistance of the fifth electric core;

the battery module further comprises a third protection unit, wherein the third protection unit comprises a third breaking device, a third detection unit and a third controller;

the third breaking device is connected in series between the second battery cell and the fifth battery cell;

the third detection unit is used for detecting third state information; the third state information is used for indicating the state of the second cell group;

the third controller is used for controlling the third breaking device to be disconnected under the condition that the third state information indicates that the second battery cells are grouped abnormally.

4. A battery module according to any one of claims 1-3, wherein the first breaking device is an explosion fuse, a contactor, a relay or a semiconductor switch.

5. The battery module according to any one of claims 1 to 4, wherein the first detection unit includes a current detection unit for detecting a current between the first cell and the second cell;

the first controller is used for controlling the first breaking device to be disconnected under the condition that the current is different from the current at the positive electrode or the negative electrode of the battery module; or,

The first controller is used for controlling the first breaking device to be disconnected under the condition that the current is larger than a first threshold value.

6. The battery module according to any one of claims 1 to 5, wherein the first detection unit includes a temperature detection unit for detecting a temperature of the first cell or the second cell;

the first controller is used for controlling the first breaking device to be disconnected under the condition that the temperature of the first battery cell or the second battery cell is larger than a second threshold value.

7. The battery module according to any one of claims 1 to 6, wherein the first detection unit includes a leakage detection circuit connected to a ground line of the battery module for detecting a current flowing through the ground line;

the first controller is used for controlling the first breaking device to be disconnected under the condition that the current flowing through the grounding wire is larger than a third threshold value.

8. The battery module of any one of claims 1-7, wherein the first detection unit and the first controller are powered by one or more cells in the battery module.

9. A battery pack, characterized in that the battery pack comprises the battery module according to any one of the preceding claims 1-7 and a first battery management unit;

the first battery management unit is used for collecting state information of the battery pack.

10. The battery pack of claim 9, further comprising a first auxiliary power source, wherein the first detection unit and the first controller in the battery module are powered by the first auxiliary power source.

11. An energy storage system comprising the battery pack of claim 9 and a second battery management unit; the second battery management unit is connected with the first battery management unit and the first controller included in the battery module;

the second battery management unit is used for receiving the state information of the battery pack acquired by the first battery management unit;

the second battery management unit is further configured to notify the first controller to control the first breaking device to be broken when the state information indicates that the battery pack is abnormal.

12. The energy storage system of claim 11, further comprising a second auxiliary power source, wherein the first detection unit and the first controller are powered by the second auxiliary power source.