Battery pack protection system, battery pack and energy storage system

Abstract

The utility model relates to a battery pack protection system, a battery pack and an energy storage system. The battery pack protection system is applied to the battery pack, the battery pack comprises at least one battery module, and the system comprises a battery management module which is respectively connected with the battery module and a voltage converter; the voltage converter is arranged in the battery pack and is connected with the load end; one end of the protection piece is connected with the battery module, and the other end of the protection piece is connected with the voltage converter; wherein the battery management module can respectively perform first protection and second protection on the battery pack according to the working states of the battery module and the voltage converter; and the protection piece can perform third protection on the battery pack according to the working state of the battery module and / or the voltage converter. The system can flexibly cope with various environments and load conditions, provides a triple protection mechanism for the battery pack, enhances the fault tolerance and reliability of the battery pack protection system, and further enhances the reliability and stability of the whole energy storage system.

Description

Technical Field

[0001] This application relates to the field of new energy technology, and in particular to a battery pack protection system, a battery pack, and an energy storage system. Background Technology

[0002] With the rapid development of new energy sources, the energy storage industry is booming, and key power equipment such as energy storage converters, uninterruptible power supplies (UPS), and photovoltaic inverters are increasingly widely used. However, these power devices have strict voltage requirements during operation; that is, they all have specific operating voltage ranges. For example, energy storage converters may only operate normally within a certain voltage range. Therefore, battery systems need to provide the corresponding voltage to match the voltage requirements of these power devices and ensure their normal operation. To meet these voltage requirements, battery packs are typically connected in series to form battery banks to achieve the required voltage. Multiple battery banks are then connected in parallel to form a battery system to meet the power requirements. However, in the above battery system, when one battery pack fails, the operation of the entire battery bank and even the entire battery system may be affected, even leading to system shutdown, thus impacting the reliability and stability of the entire power system. Therefore, appropriate protection measures for battery packs are necessary.

[0003] In existing battery packs, a single protection mechanism is used to protect the battery pack, which can prevent some extreme situations from occurring.

[0004] However, traditional single protection mechanisms usually only focus on protecting one aspect, such as simply overvoltage or undervoltage, or overtemperature. But in practical applications, battery packs may encounter a variety of complex fault conditions, and a single protection mechanism cannot cope with complex changes, thereby reducing the reliability and stability of the battery pack and even the battery system. Utility Model Content

[0005] Therefore, it is necessary to address the aforementioned technical issues by providing a battery pack protection system, battery pack, and energy storage system that can flexibly cope with various environmental and load conditions, offer a triple protection mechanism, and enhance the fault tolerance and reliability of the battery pack protection system.

[0006] This application provides a battery pack protection system for use in a battery pack, the battery pack including at least one battery module, the system comprising:

[0007] The battery management module is connected to both the battery module and the voltage converter.

[0008] A voltage converter, located inside the battery pack, is capable of connecting to a load; and

[0009] A protective component, one end of which is connected to the battery module and the other end to the voltage converter;

[0010] The battery management module can provide first protection for the battery pack based on the working status of the battery module; and can provide second protection for the battery pack based on the working status of the voltage converter; and the protection device can provide third protection for the battery pack based on the working status of the battery module and / or the voltage converter.

[0011] In one embodiment, the battery pack protection system further includes a hot-swappable interface, the first end of which is connected to a voltage converter, and the second end of which can be connected to a busbar and connected to a load via the busbar.

[0012] In one embodiment, the battery management module communicates with the battery module and the voltage converter, and is able to obtain the operating status of the battery module and the voltage converter; the battery management module can control the connection and disconnection between the battery module and the battery management module according to the operating status of the battery module, and the battery management module can control the connection and disconnection between the voltage converter and the battery management module according to the operating status of the voltage converter.

[0013] In one embodiment, the battery management module is communicatively connected to the battery module and can disconnect the battery module from the battery management module when the battery module's operating state is abnormal, thereby providing a first protection for the battery pack; the battery management module is communicatively connected to the voltage converter and can disconnect the voltage converter from the battery management module when the voltage converter's operating state is abnormal, thereby providing a second protection for the battery pack.

[0014] In one embodiment, the protective element is a fuse or circuit breaker that can disconnect the electrical connection between the battery module and the voltage converter to provide a third protection for the battery pack.

[0015] In one embodiment, the battery management module is communicatively connected to the battery module and can obtain the working status of the battery module; when the battery module is in normal working state, the battery management module controls the voltage converter to connect with the battery management module, and the battery module supplies power to the voltage converter.

[0016] In one embodiment, the battery management module is communicatively connected to the voltage converter. The battery management module can obtain the operating status of the voltage converter and charge or discharge the battery module according to the operating status of the voltage converter.

[0017] In one embodiment, the voltage converter includes an output terminal, which includes a positive output terminal and a negative output terminal. The battery management module is able to acquire the voltage or current between the positive output terminal and the negative output terminal, and can control the battery module to charge or discharge according to the voltage or current.

[0018] Secondly, this application provides a battery pack including any of the battery pack protection systems provided in the first aspect.

[0019] Thirdly, this application provides an energy storage system including at least two battery packs provided in the second aspect, wherein voltage converters within the at least two battery packs are communicatively connected.

[0020] The aforementioned battery pack protection system, battery pack, and battery assembly are described above. The battery pack protection system is applied to a battery pack, which includes at least one battery module. The system includes: a battery management module connected to both the battery module and a voltage converter; a voltage converter located inside the battery pack and capable of connecting to a load; and a protective element connected at one end to the battery module and at the other end to the voltage converter. The battery management module can provide first protection to the battery pack based on the operating state of the battery module; it can also provide second protection based on the operating state of the voltage converter; and the protective element can provide third protection based on the operating state of the battery module and / or the voltage converter. This battery pack protection system can flexibly respond to various environmental and load conditions, providing a triple protection mechanism for the battery pack, enhancing the fault tolerance and reliability of the battery pack protection system, and thus enhancing the reliability and stability of the battery assembly and even the entire battery system. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the battery pack protection system in one embodiment. Detailed Implementation

[0023] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0024] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0026] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0027] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0028] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0029] Existing battery systems, to meet the voltage requirements of power equipment, use battery packs connected in series to form battery banks, and then connect multiple battery banks in parallel to form a battery system to meet the power requirements. In existing battery systems, when a battery pack fails, the entire battery bank or even the entire battery system shuts down, affecting the stability and availability of the equipment. Ensuring the reliability of the battery pack and preventing system downtime due to the failure of a single battery pack has become a pressing issue. Therefore, this application proposes a battery pack protection system that provides at least three protection mechanisms to flexibly cope with various environmental and load conditions, enhancing the fault tolerance and reliability of the battery pack protection system. Simultaneously, this application connects a hot-swappable interface to the voltage converter port, enabling rapid insertion and removal of individual battery packs and facilitating the quick replacement of faulty battery packs, thereby improving the maintenance efficiency of the battery bank and solving the problem of the entire battery bank or even the battery system shutting down due to the failure of a single battery pack. Furthermore, the hot-swappable interface allows for online hot-swapping of the battery pack, improving the convenience of expanding the battery bank and battery system capacity.

[0030] Firstly, this utility model provides a battery pack protection system.

[0031] Please see Figure 1 , Figure 1 A schematic diagram of a battery pack protection system according to an embodiment of the present invention is shown. The battery pack protection system provided in this embodiment is applied to a battery pack, which includes at least one battery module. The battery pack protection system includes: a battery management module connected to both the battery module and a voltage converter; a voltage converter disposed inside the battery pack and capable of connecting to a load terminal; and a protective element, one end of which is connected to the battery module and the other end to the voltage converter. The battery management module can provide first protection to the battery pack based on the operating state of the battery module; and can provide second protection to the battery pack based on the operating state of the voltage converter; and the protective element can provide third protection to the battery pack based on the operating state of the battery module and / or the voltage converter.

[0032] The battery management module refers to the battery management system (BMS), and the voltage converter refers to the direct current to direct current converter (DC-DC). The voltage converter (DC-DC converter) is built into the battery pack. The two ends of the BMS are connected to the battery module and the voltage converter, respectively. The BMS is used to monitor the operating status of the battery module and the voltage converter in real time to determine whether the battery module and the voltage converter are in a safe operating state.

[0033] The battery management module is communicatively connected to the battery module and the voltage converter, and can acquire the operating status of the battery module and the voltage converter. The battery management module can control the connection and disconnection between the battery module and the battery management module according to the operating status of the battery module, and the battery management module can control the connection and disconnection between the voltage converter and the battery management module according to the operating status of the voltage converter.

[0034] For example, the BMS communicates with the battery module. The BMS acquires various data from the battery module, such as voltage, current, and temperature, to determine if the battery module is in a safe operating state. When the BMS detects an abnormality in the battery module's operating state, it takes protective measures. Specifically, the BMS directly disconnects the connection between the battery management module and the battery module, forming the first line of protection for the battery pack and preventing battery damage or danger. Specifically, when the BMS detects an abnormality in the battery module's operating state, it automatically disconnects the connection between the battery module's negative terminal (B0-) and the BMS (B-), thereby isolating the abnormal battery module and ensuring the overall safe operation of the system.

[0035] The DC-DC converter and BMS communicate with each other via a communication protocol, exchanging data in real time. The BMS can obtain the DC-DC converter's operating parameters in real time to determine if the converter is in a safe operating state. When the BMS detects an abnormal operating state of the DC-DC converter, it takes protective measures, namely, directly disconnecting the connection between the voltage converter and the battery management module, forming a second protection for the battery pack. Specifically, when the BMS detects an abnormal operating state of the DC-DC converter, it automatically disconnects the connection between the BMS output negative terminal (C-) and the low-voltage side negative terminal (B1-) of the DC-DC converter, preventing the abnormal DC-DC converter from affecting other components.

[0036] Based on the above exemplary embodiments, the battery pack protection system further includes a protective component; one end of the protective component is connected to the battery module, and the other end is connected to the voltage converter. This protective component can disconnect the electrical connection between the battery module and the voltage converter to provide a third layer of protection for the battery pack. The protective component is a fuse or a circuit breaker.

[0037] Optionally, a protective device is used to detect the current data between the battery module and the voltage converter, and to provide fuse protection when the current data exceeds the fuse current. Specifically, a protective device is connected between the positive terminal (B0+) of the battery module and the positive terminal (B1+) of the low-voltage side of the DC-DC converter. This protective device operates according to a preset fuse current. When an abnormality occurs in the battery module or the DC-DC converter, and the current data exceeds the preset fuse current of the protective device, the protective device melts, thereby cutting off the current path between the positive terminal (B0+) of the battery module and the positive terminal (B1+) of the low-voltage side of the DC-DC converter, forming a third protection for the battery pack, thus protecting the system.

[0038] In this implementation, the Battery Management System (BMS) monitors the operating status of the battery module and voltage converter in real time, disconnecting the corresponding connections when an anomaly is detected. This provides first and second protection for the battery pack, enhancing the overall safety and reliability of the system. Building upon the BMS control and protection, further protective components are added to form a third layer of protection for the battery pack, further improving its overcurrent protection capability. In other words, this battery pack protection system provides a triple protection mechanism, enabling it to flexibly respond to various environmental and load conditions, enhancing its fault tolerance and reliability, and ensuring stable operation of the battery pack under complex operating conditions.

[0039] In one exemplary embodiment, the battery pack protection system further includes a hot-swappable interface, a first end of which is connected to a voltage converter, and a second end which can be connected to a busbar and connected to a load via the busbar.

[0040] Please see Figure 1 The negative terminal (P-) of the high-voltage side of the DC-DC converter is connected to the negative terminal of the hot-swap port, and the positive terminal (P+) of the high-voltage side of the DC-DC converter is connected to the positive terminal of the hot-swap port; this allows the DC-DC converter to be connected to the busbar through the hot-swap interface and to the load end through the busbar.

[0041] The hot-swappable interface is used to electrically connect or disconnect the device when it is powered on without affecting its normal operation. The busbar is used to collect electrical energy from at least one battery pack and distribute it to the load. The first end of the voltage converter is connected to the first interface of the hot-swappable interface, and the second end of the voltage converter is connected to the second interface of the hot-swappable interface. The hot-swappable interface enables the connection and disconnection between the battery pack and the load.

[0042] Hot-swappable interfaces enable more flexible electrical connections between the battery pack and the load, supporting rapid replacement, repair, or maintenance of the battery pack. For example, when a battery pack fails or needs replacement or upgrade, simply disconnect the faulty battery pack from the busbar via the hot-swappable interface and then insert the new battery pack without affecting the normal operation of other battery packs in the battery pack. Furthermore, when it is necessary to expand the battery pack and battery system capacity, new battery packs can be quickly connected via the hot-swappable interface. This process allows users to increase battery capacity without downtime or reconfiguring the entire system, providing operational convenience and battery system flexibility, and greatly improving the scalability of the battery system.

[0043] Traditional battery pack systems often require shutdown or power outages for maintenance and replacement. In this embodiment, however, the battery pack is connected to the busbar via a hot-swappable interface, making battery pack replacement more efficient and faster without affecting the overall operation of the battery pack and the entire battery system, thus enhancing their flexibility. Furthermore, operators can expand the battery pack and system as needed without rewiring or reconfiguring the battery system power supply, improving the flexibility, scalability, and maintainability of the battery pack and system.

[0044] In an exemplary embodiment, the battery management module is communicatively connected to the battery module and can obtain the working status of the battery module; when the battery module is in normal working state, the battery management module controls the voltage converter to connect with the battery management module, and the battery module supplies power to the voltage converter.

[0045] For example, the BMS communicates with the battery module, enabling the BMS to acquire the battery module's operating status. When the BMS detects that the battery module is in normal operating condition, it controls the voltage converter to connect with the battery management module, allowing the battery module to supply power to the voltage converter. Specifically, after the BMS detects that the battery module is in normal operating condition, it controls the BMS (B-) to conduct with the BMS output negative terminal (C-), allowing the battery module negative terminal (B0-) and the BMS output negative terminal (C-) to provide power to the DC-DC converter. A communication connection is then established between the BMS and the DC-DC converter, and the DC-DC converter enters standby mode.

[0046] In an exemplary embodiment, the battery management module is communicatively connected to the voltage converter. When the battery module supplies power to the voltage converter, the battery management module can obtain the operating status of the voltage converter and charge or discharge the battery module according to the operating status of the voltage converter.

[0047] The voltage converter includes an output terminal, which includes a positive output terminal and a negative output terminal. The battery management module can acquire the voltage or current between the positive output terminal and the negative output terminal, and can control the battery module to charge or discharge according to the voltage or current.

[0048] Optionally, the Battery Management Module (BMS) controls the BMS (B-) to conduct with the BMS output negative terminal (C-), enabling the battery module to provide power to the converter. At this time, a communication connection is established between the Battery Management Module and the voltage converter. The Battery Management Module can monitor the voltage or current parameters at the voltage converter output in real time. Specifically, when the BMS detects that the voltage between the positive and negative output terminals of the voltage converter is lower than a preset voltage threshold, it determines that the voltage converter is in boost mode. In this case, the BMS controls the battery module to discharge to provide power to the voltage converter. When the BMS detects that the voltage between the positive and negative output terminals of the voltage converter is higher than the voltage threshold, it indicates that the voltage converter is in buck mode. The BMS then controls the battery module to charge, thereby absorbing excess energy and storing it inside the battery. The voltage threshold can be set according to actual conditions and is not specifically limited here.

[0049] In this embodiment, the battery management module (BMS) can obtain the operating status of the voltage converter and dynamically control the battery module according to the operating status of the voltage converter, thereby ensuring the safe operation of the system while realizing the rational flow and effective utilization of electrical energy.

[0050] In another embodiment, a battery pack protection system is provided for use in a battery pack, the battery pack including at least one battery module. The system includes a battery management module, a voltage converter, a protection element, and a hot-swappable interface. The battery management module is connected to both the battery module and the voltage converter, the voltage converter being located inside the battery pack. A first end of the hot-swappable interface is connected to the voltage converter, and a second end of the hot-swappable interface can be connected to a busbar, and the hot-swappable interface can be connected to the load terminal via the busbar.

[0051] The battery management module is communicatively connected to the battery module. The battery management module can obtain the working status of the battery module and control the connection and disconnection between the battery module and the battery management module according to the working status of the battery module. Specifically, the battery management module can disconnect the battery module from the battery management module when the working status of the battery module is abnormal, so as to provide the first protection for the battery pack.

[0052] The battery management module is communicatively connected to the voltage converter; the battery management module can obtain the operating status of the voltage converter and control the connection and disconnection between the voltage converter and the battery management module according to the operating status of the voltage converter; specifically, the battery management module can disconnect the voltage converter from the battery management module when the operating status of the voltage converter is abnormal, so as to provide a second protection for the battery pack.

[0053] One end of the protective device is connected to the battery module, and the other end is connected to the voltage converter. The protective device can provide third-party protection for the battery pack based on the operating status of the battery module and / or the voltage converter. Specifically, the protective device can disconnect the electrical connection between the battery module and the voltage converter to provide third-party protection for the battery pack. The protective device is a fuse or circuit breaker.

[0054] The battery management module communicates with the battery module and can acquire the operating status of the battery module. When the battery management module determines that the battery module is in a normal operating state, it controls the voltage converter to connect to the battery management module, and the battery module supplies power to the voltage converter. The battery management module can also acquire the operating status of the voltage converter and charge or discharge the battery module according to the operating status of the voltage converter. The voltage converter includes an output terminal, which includes a positive output terminal and a negative output terminal. The battery management module can acquire the voltage or current between the positive and negative output terminals and control the battery module to charge or discharge according to the voltage or current.

[0055] In this embodiment, if any of the battery modules, battery management modules, or voltage converters malfunctions during the operation of the battery pack, the individual battery pack stops working, preventing a single battery pack from affecting the stability of the entire battery system. Furthermore, the malfunctioning battery pack can be quickly replaced with a normal battery pack via a hot-swappable interface to ensure the normal operation of the battery system.

[0056] Secondly, this application provides a battery pack including any of the battery pack protection systems provided in the first aspect.

[0057] For example, the battery pack includes any of the battery pack protection systems provided in the first aspect. The battery pack protection system protects the battery pack through multiple protection mechanisms, which can ensure the safe, stable and efficient operation of the battery pack throughout its entire life cycle.

[0058] Thirdly, this application provides an energy storage system including at least two battery packs provided in the second aspect, wherein voltage converters within the at least two battery packs are communicatively connected.

[0059] The energy storage system includes at least two battery packs provided in the second aspect, each battery pack including any one of the battery pack protection systems provided in the first aspect. For example, please refer again... Figure 1 Taking battery pack N as an example, the battery modules within battery pack N provide power to the BMS. The BMS determines whether the battery modules are in normal operating condition based on their relevant parameter information. When the BMS determines that the battery modules are in normal operating condition, it controls the BMS (B-) to conduct with the BMS output negative terminal (C-). At this time, the battery module negative terminal (B0-) and the BMS output negative terminal (C-) provide power to the DC-DC converter, and a communication connection is established between the BMS and the DC-DC converter. Under these conditions, communication connections are also established between the DC-DC converters within each battery pack (battery pack 1, battery pack 2, ..., battery pack N), allowing the DC-DC converter in each battery pack to obtain real-time operating status information from the DC-DC converters in other battery packs. Furthermore, in scenarios where multiple battery packs operate collaboratively, the operating state of the DC-DC converter in any battery pack (e.g., boost or buck operation) will be dynamically adjusted according to the operating state of the DC-DC converters in other battery packs. This achieves synchronization of the operating states of the DC-DC converters among multiple battery packs, effectively ensuring the output consistency of each battery pack when working collaboratively and the overall operational stability of the system, thereby improving the coordination and reliability of the energy storage system.

[0060] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0061] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A battery pack protection system, applied to a battery pack, the battery pack comprising at least one battery module, characterized in that, The system includes: A battery management module is connected to both the battery module and the voltage converter. A voltage converter, disposed inside the battery pack, is capable of connecting to a load; and A protective component, one end of which is connected to the battery module and the other end of which is connected to the voltage converter; The battery management module can provide first protection for the battery pack based on the working state of the battery module; and can provide second protection for the battery pack based on the working state of the voltage converter; and the protective device can provide third protection for the battery pack based on the working state of the battery module and / or the voltage converter.

2. The system according to claim 1, characterized in that, It also includes a hot-swappable interface, the first end of which is connected to the voltage converter, and the second end of which can be connected to the busbar and connected to the load end through the busbar.

3. The system according to claim 1, characterized in that, The battery management module is communicatively connected to the battery module and the voltage converter, and can obtain the working status of the battery module and the voltage converter. The battery management module can control the connection and disconnection between the battery module and the battery management module according to the working status of the battery module, and the battery management module can control the connection and disconnection between the voltage converter and the battery management module according to the working status of the voltage converter.

4. The system according to claim 3, characterized in that, The battery management module is communicatively connected to the battery module and can disconnect the battery module from the battery management module when the battery module's working state is abnormal, thereby providing a first protection for the battery pack; the battery management module is communicatively connected to the voltage converter and can disconnect the voltage converter from the battery management module when the voltage converter's working state is abnormal, thereby providing a second protection for the battery pack.

5. The system according to claim 1, characterized in that, The protective component is a fuse or circuit breaker, which can disconnect the electrical connection between the battery module and the voltage converter to provide a third protection for the battery pack.

6. The system according to claim 1, characterized in that, The battery management module is communicatively connected to the battery module and can obtain the working status of the battery module. When the battery module is in normal working condition, the battery management module controls the voltage converter to connect with the battery management module, and the battery module supplies power to the voltage converter.

7. The system according to claim 6, characterized in that, The battery management module is communicatively connected to the voltage converter. The battery management module can obtain the working status of the voltage converter and charge or discharge the battery module according to the working status of the voltage converter.

8. The system according to claim 7, characterized in that, The voltage converter includes an output terminal, which includes a positive output terminal and a negative output terminal. The battery management module can acquire the voltage or current between the positive output terminal and the negative output terminal, and can control the battery module to charge or discharge according to the voltage or current.

9. A battery pack, characterized in that, The battery pack protection system includes any one of claims 1 to 8.

10. An energy storage system, characterized in that, The battery pack includes the battery pack of claim 9, wherein the number of battery packs is at least two, and the voltage converters within each battery pack are communicatively connected.

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