Battery charging and discharging method of energy storage system and energy storage system

Abstract

The embodiment of the application relates to the technical field of energy storage, and provides a battery charging and discharging method of an energy storage system and the energy storage system. The battery charging and discharging method of the energy storage system comprises the following steps: monitoring single battery voltage and total battery voltage; in the case that the single battery voltage meets a first preset condition, starting a first multi-stage protection strategy, the strategy comprising taking different charging and discharging protection measures when the single battery voltage reaches different preset values; and in the case that the total battery voltage meets a second preset condition, starting a second multi-stage protection strategy, the strategy comprising taking different charging and discharging protection measures when the total battery voltage reaches different preset values. The technical scheme of the application can effectively solve the problem that, in the prior art, the overvoltage protection mechanism is single, fine protection cannot be provided according to different voltage levels, and thus the safety of the energy storage system is insufficient.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage, and in particular to a battery charging and discharging method of an energy storage system and the energy storage system. BACKGROUND

[0002] Overvoltage protection function is an important part of safety guarantee of energy storage system, which is used to prevent damage or safety incidents of battery due to high voltage.

[0003] Current energy storage converters are generally equipped with overvoltage protection mechanisms to avoid overcharging of the battery, but these mechanisms are usually triggered by a single threshold. Once the battery voltage reaches the preset overvoltage protection point, immediate action is taken, such as stopping charging. Although this can provide basic safety protection, it has certain limitations in actual application. Specifically, a single overvoltage protection point cannot fully consider the differences in different battery systems and working environments. For example, in a low-temperature environment, the upper limit of the charging voltage of the battery may be higher than that in a normal temperature environment. A single overvoltage protection point may cause premature interruption of charging, thereby affecting the charging efficiency of the battery and the performance of the entire energy storage system. SUMMARY

[0004] The embodiments of the present application provide a battery charging and discharging method of an energy storage system and the energy storage system, which at least solve the problem that the overvoltage protection mechanism in the prior art is single and cannot provide fine protection according to different voltage levels, thereby causing insufficient safety of the energy storage system.

[0005] According to some embodiments of the present application, the embodiments of the present application provide a battery charging and discharging method of an energy storage system, comprising: monitoring a single battery voltage and a total battery voltage; in a case where the single battery voltage meets a first preset condition, starting a first multi-level protection strategy, the first multi-level protection strategy comprising adopting different charging and discharging protection strategies when the single battery voltage reaches different preset single voltages; in a case where the total battery voltage meets a second preset condition, starting a second multi-level protection strategy, the second multi-level protection strategy comprising adopting different charging and discharging protection strategies when the total battery voltage reaches different preset total voltages.

[0006] In some embodiments, before starting the first multi-level protection strategy in a case where the single battery voltage meets the first preset condition, the method further comprises: in a case where the single battery voltage reaches any of the preset single voltages and is maintained for a corresponding time length, determining that the single battery voltage meets the first preset condition; before starting the second multi-level protection strategy in a case where the total battery voltage meets the second preset condition, the method further comprises: in a case where the total battery voltage reaches any of the preset total voltages and is maintained for a corresponding time length, determining that the total battery voltage meets the second preset condition.

[0007] In some embodiments, the first multi-level protection strategy includes a first sub-protection strategy, a second sub-protection strategy, and a third sub-protection strategy. When the single battery voltage meets a first preset condition, the first multi-level protection strategy is started, including: when the single battery voltage reaches a first preset single battery voltage and maintains for a first time length, the first sub-protection strategy is started, the first sub-protection strategy being to control the PCS charge-discharge power to drop to a first charge-discharge power; when the single battery voltage reaches a second preset single battery voltage and maintains for a second time length, the second sub-protection strategy is started, the second sub-protection strategy being to control the PCS charge-discharge power to drop to a second charge-discharge power; when the single battery voltage reaches a third preset single battery voltage and maintains for a third time length, the third sub-protection strategy is started, the third sub-protection strategy being to control the PCS charge-discharge power to drop to a third charge-discharge power; wherein the first preset single battery voltage is less than the second preset single battery voltage, the second preset single battery voltage is less than the third preset single battery voltage, the first time length is greater than the second time length, the second time length is greater than the third time length, the first charge-discharge power is greater than the second charge-discharge power, and the second charge-discharge power is greater than the third charge-discharge power.

[0008] In some embodiments, the second multi-level protection strategy includes a fourth sub-protection strategy, a fifth sub-protection strategy, and a sixth sub-protection strategy. When the total battery voltage meets a second preset condition, the second multi-level protection strategy is started, including: when the total battery voltage reaches a first preset total voltage and maintains for a fourth time length, the fourth sub-protection strategy is started, the fourth sub-protection strategy being to control the PCS charge-discharge power to drop to a fourth charge-discharge power; when the single battery voltage reaches a second preset total voltage and maintains for a fifth time length, the fifth sub-protection strategy is started, the fifth sub-protection strategy being to control the PCS charge-discharge power to drop to a fifth charge-discharge power; when the single battery voltage reaches a third preset total voltage and maintains for a sixth time length, the sixth sub-protection strategy is started, the sixth sub-protection strategy being to control the PCS charge-discharge power to drop to a sixth charge-discharge power; wherein the first preset total voltage is less than the second preset total voltage, the second preset total voltage is less than the third preset total voltage, the fourth time length is greater than the fifth time length, the fifth time length is greater than the sixth time length, the fourth charge-discharge power is greater than the fifth charge-discharge power, and the fifth charge-discharge power is greater than the sixth charge-discharge power.

[0009] In some embodiments, when the voltage of the single battery cell meets a first preset condition, a first multi-level protection strategy is activated, including: when the voltage of the single battery cell meets the first preset condition, activating one of an alarm strategy, a charge / discharge restriction strategy, and a high-voltage power-down strategy, wherein the alarm strategy is to adjust the PCS to enter a constant voltage charging mode, the charge / discharge restriction strategy is to limit the charging and discharging power of the PCS, and the high-voltage power-down strategy is to reduce the charging and discharging power of the PCS to zero.

[0010] In some embodiments, the method further includes: predicting the predicted individual cell voltage and the predicted total battery voltage at a future target time point based on the individual cell voltage and the total battery voltage obtained in the current time period; activating a first pre-protection strategy based on the predicted individual cell voltage, the first pre-protection strategy including at least one of pre-reducing the PCS charging and discharging power, pre-enhancing cooling, and optimizing load charging distribution; and activating a second pre-protection strategy based on the predicted individual cell voltage, the second pre-protection strategy including at least one of pre-reducing the PCS charging and discharging power, pre-disconnecting the charging branch, and pre-fault isolation.

[0011] According to some embodiments of this application, another aspect of this application provides an energy storage system, including: multiple battery clusters, each battery cluster including multiple individual batteries connected in series; multiple battery management units, electrically connected to each individual battery; multiple battery control units, one of which is connected to the multiple battery management units via a bus, the number of battery control units being equal to the number of battery clusters; a network switch and a system control unit, each of the battery control units being connected to the network switch via a bus, and the network switch being connected to the system control unit via a bus; an energy storage converter, connected to the system control unit via a bus, and connected to the individual batteries via a charging branch; wherein, the battery management units are used to acquire the voltage of the individual batteries, the battery control units are used to activate a first multi-level protection strategy when the voltage of the individual batteries meets a first preset condition, the first multi-level protection strategy including adopting different charge and discharge protection strategies when the voltage of the individual batteries reaches different preset individual battery voltages, the energy storage converter is used to monitor the total battery voltage, and is used to activate a second multi-level protection strategy when the total battery voltage meets a second preset condition, the second multi-level protection strategy including adopting different charge and discharge protection strategies when the total battery voltage reaches different preset total voltages.

[0012] According to some embodiments of this application, the energy storage system further includes an energy management system connected to the system control unit via a bus.

[0013] According to some embodiments of this application, the energy storage system further includes: a plurality of high-voltage boxes, wherein a battery control unit and a charging branch are distributed in one of the high-voltage boxes.

[0014] According to some embodiments of this application, another aspect of this application provides an energy storage system, including: multiple battery clusters, each battery cluster including multiple individual cells connected in series; multiple battery management units, electrically connected to each individual cell; multiple energy storage converters, each energy storage converter including a battery control unit, a charging branch and an auxiliary control unit, one battery control unit being connected to multiple battery management units via a bus, the number of battery control units being equal to the number of battery clusters; a network switch and a system control unit, each energy storage converter being connected to the network switch via a bus, the network switch being connected to the system control unit via a bus; wherein, the battery management unit is used to acquire the voltage of an individual cell, the battery control unit is used to activate a first multi-level protection strategy when the voltage of an individual cell meets a first preset condition, the first multi-level protection strategy including adopting different charge and discharge protection strategies when the voltage of an individual cell reaches different preset individual cell voltages, the auxiliary control unit is used to monitor the total battery voltage, and is used to activate a second multi-level protection strategy when the total battery voltage meets a second preset condition, the second multi-level protection strategy including adopting different charge and discharge protection strategies when the total battery voltage reaches different preset total voltages.

[0015] According to some embodiments of this application, the energy storage system further includes an energy management system connected to the system control unit via a bus.

[0016] According to some embodiments of this application, the energy storage system further includes: a plurality of battery cabinets, the number of which is equal to the number of battery clusters; wherein, one battery cluster, one energy storage converter, the network switch, and the system control unit are integrated in a target battery cabinet, the target battery cabinet being one of the plurality of battery cabinets, and a non-target battery cabinet integrating one battery cluster and one energy storage converter.

[0017] According to some embodiments of this application, the energy storage converter further includes a DC-AC converter electrically connected to the charging branch.

[0018] According to some embodiments of this application, one of the charging branches includes: a circuit breaker, a contactor module and a fuse connected in series, one end of the circuit breaker being electrically connected to the single battery cell and one end of the fuse being electrically connected to one end of the DC-AC converter.

[0019] According to some embodiments of this application, the energy storage system further includes: a dehumidifier, a liquid cooler, a temperature and humidity sensor, and a water immersion sensor, which communicate with the battery control unit via a bus.

[0020] The technical solution provided in this application has at least the following advantages: it not only monitors the voltage of individual cells, but also the total voltage of the entire battery pack, and activates corresponding multi-level protection strategies based on the monitoring results. This comprehensive monitoring method ensures all-round protection from the microscopic individual cells to the macroscopic whole of the battery pack, improving the safety and reliability of the system. Setting different preset individual cell voltages and preset total voltages fully considers the differences in different battery systems and operating environments. The first and second multi-level protection strategies adopt different levels of charge and discharge protection measures based on the voltage level, meaning that the more severe the overvoltage situation, the more stringent the protection measures taken by the system. This graded response effectively avoids the waste of resources caused by over-protection, while ensuring that the system can respond quickly when emergency intervention is truly needed, avoiding major accidents. By dynamically adjusting the charge and discharge strategies, the performance and lifespan of the battery pack can be maintained as much as possible while ensuring battery safety. This set of protection measures takes action at the initial stage of overvoltage, which is equivalent to providing a fault warning, allowing the system to intervene at the small problem stage and preventing further escalation of the problem. Through preventive protection measures, the system can reduce the battery failure rate, extend the lifespan of the battery pack, and reduce maintenance costs. It can effectively solve the problem that the existing overvoltage protection mechanism is too simple and cannot provide fine protection according to different voltage levels, thus resulting in insufficient safety of energy storage systems. Attached Figure Description

[0021] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the drawings in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this application or in the conventional art, the drawings used in the embodiments will be briefly introduced below. Obviously, the 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 flowchart of a battery charging and discharging method for an energy storage system provided in an embodiment of this application;

[0023] Figure 2 This is a schematic diagram of a battery charging and discharging method for a specific energy storage system provided in an embodiment of this application;

[0024] Figure 3This is a schematic diagram of a battery charging and discharging method for another specific energy storage system provided in an embodiment of this application;

[0025] Figure 4 This is a schematic diagram of an energy storage system provided in an embodiment of this application;

[0026] Figure 5 This is a schematic diagram of another energy storage system provided in an embodiment of this application. Detailed Implementation

[0027] As is known from the background art, a single overvoltage protection point cannot fully account for the differences between different battery systems and operating environments. To address the problem that a single overvoltage protection point cannot fully account for the differences between different battery systems and operating environments, embodiments of this application provide a battery charging and discharging method and an energy storage system.

[0028] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0029] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0030] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0031] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0032] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0033] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" 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. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0034] In the accompanying drawings corresponding to the embodiments of this application, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be a third component between the two components. Conversely, when describing a component on the surface of another component, or when another component is formed or disposed on the surface of a component, it indicates that there is no third component between the two components. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0035] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included. Furthermore, when a component such as a layer, film, region, or plate is referred to as being "on / located" on another component, it can be "directly on" the other component (i.e., located on the surface of the other component with no other components between them), or another component may be present therein. Moreover, when a component such as a layer, film, region, or plate is "directly located" on another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it indicates that no other components are located therein.

[0036] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "part" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0037] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0038] Embodiments of this application provide a battery charging and discharging method for an energy storage system. Figure 1 This is a flowchart of a battery charging and discharging method for an energy storage system according to an embodiment of this application. Figure 1 As shown, the method includes the following steps:

[0039] Step S101: Monitor the voltage of individual cells and the total battery voltage;

[0040] A battery cluster or battery pack is composed of multiple individual cells connected in series or parallel. The voltage of an individual cell refers to the voltage of that individual cell, while the total voltage of the battery pack refers to the voltage of the entire battery pack.

[0041] Step S102: When the voltage of the above-mentioned single cell meets the first preset condition, the first multi-level protection strategy is activated. The first multi-level protection strategy includes adopting different charge and discharge protection strategies when the voltage of the above-mentioned single cell reaches different preset single cell voltages.

[0042] Once the voltage of a single battery cell is detected to meet the first preset condition, a multi-level protection strategy will be activated. This strategy provides different levels of protection response based on the severity of the overvoltage. The multi-level strategy means that the protection mechanism is not a one-size-fits-all approach, but rather escalates gradually according to the severity of the overvoltage, resulting in a more precise and effective response.

[0043] Step S103: When the total battery voltage meets the second preset condition, the second multi-level protection strategy is activated. The second multi-level protection strategy includes adopting different charge and discharge protection strategies when the total battery voltage reaches different preset total voltages.

[0044] When the total pressure meets the second preset condition mentioned above, the most severe measures will not be taken immediately. Instead, protection strategies will be implemented gradually according to the level of total pressure. This multi-level strategy can control the response more precisely and avoid taking excessive protection measures when the problem is not serious, thereby affecting the normal use and efficiency of the battery pack.

[0045] It should be noted that the solution of this application, including S101, S102 and S103, can be applied to both the battery charging process and the battery discharging process.

[0046] Through steps S101, S102, and S103, not only is the voltage of individual cells monitored, but also the total voltage of the entire battery pack is monitored, and corresponding multi-level protection strategies are activated based on the monitoring results. This comprehensive monitoring method ensures all-round protection from the microscopic individual cells to the macroscopic overall battery pack, improving the safety and reliability of the system. Setting different preset individual cell voltages and preset total voltages fully considers the differences in different battery systems and operating environments. The first and second multi-level protection strategies adopt different levels of charge and discharge protection measures based on the voltage level, meaning that the more severe the overvoltage situation, the more stringent the protection measures taken by the system. This graded response effectively avoids the waste of resources caused by over-protection, while ensuring that the system can respond quickly when emergency intervention is truly needed, avoiding major accidents. By dynamically adjusting the charge and discharge strategies, the performance and lifespan of the battery pack can be maintained as much as possible while ensuring battery safety. This set of protection measures takes action at the initial stage of overvoltage, which is equivalent to providing a fault warning, allowing the system to intervene at the small problem stage and preventing further escalation of the problem. Through preventive protection measures, the system can reduce the battery failure rate, extend the battery pack's lifespan, and reduce maintenance costs. It can effectively solve the problem that the existing overvoltage protection mechanism is too simple and cannot provide fine protection according to different voltage levels, thus resulting in insufficient safety of energy storage systems.

[0047] In a specific implementation, before activating the first multi-level protection strategy when the voltage of the aforementioned single cell meets the first preset condition, the method further includes: determining that the voltage of the aforementioned single cell meets the first preset condition when the voltage of the aforementioned single cell reaches any of the aforementioned preset single cell voltages and is maintained for the corresponding duration.

[0048] By monitoring individual battery voltages and setting different preset individual battery voltage thresholds, the system can react promptly when the battery voltage begins to approach an unsafe range. More importantly, by requiring the voltage to remain above the preset threshold for a certain period before triggering protection, false alarms caused by instantaneous voltage fluctuations can be effectively avoided, improving the accuracy and stability of overvoltage detection.

[0049] Some overvoltage protection solutions trigger immediately when the voltage first exceeds a threshold. While this provides a rapid response, it can lead to unnecessary battery usage limitations in certain situations. This solution, by setting a duration of overvoltage protection, allows the system to intelligently determine whether an overvoltage situation truly requires intervention, thereby minimizing the impact on normal battery operation while ensuring safety.

[0050] By adopting different levels of charge and discharge protection strategies under different preset cell voltages, the charging and discharging process of the battery can be controlled more precisely, avoiding the impact of sudden and drastic changes in charging current or power on the battery, protecting the battery's health and extending its service life.

[0051] See details Figure 2 During battery charging, a single cell voltage rising to 3550mV and maintaining it for 185s indicates a level one overvoltage; a single cell voltage rising to 3600mV and maintaining it for 25s indicates a level two overvoltage; and a single cell voltage rising to 3630mV and maintaining it for 12s indicates a level three overvoltage.

[0052] See details Figure 3 During battery discharge, a single cell voltage dropping to 2850mV and remaining there for 12 seconds indicates a level 3 overvoltage; a single cell voltage dropping to 2800mV and remaining there for 25 seconds indicates a level 2 overvoltage; and a single cell voltage dropping to 2550mV and remaining there for 185 seconds indicates a level 1 overvoltage.

[0053] Before activating the second multi-level protection strategy when the total battery voltage meets the second preset condition, the method further includes: determining that the total battery voltage meets the second preset condition when the total battery voltage reaches any of the preset total voltages and is maintained for a corresponding duration.

[0054] By setting the battery total voltage to be maintained for a certain period of time after reaching the preset total voltage before triggering the protection, false alarms caused by measurement noise or short-term voltage fluctuations can be avoided, ensuring that the overvoltage protection is accurately triggered when there is a real risk of overvoltage, thus enhancing the stability and accuracy of the protection logic.

[0055] In battery total voltage monitoring, instantaneous voltage peaks may occur. Without time limits, these peaks may erroneously trigger protection mechanisms, affecting the normal operation of the energy storage system. By increasing the required maintenance duration, the system can eliminate interference from transient peaks and respond only to sustained overvoltage conditions, thus improving its intelligent decision-making capabilities.

[0056] This condition, added before activating the second-level protection strategy, means that further protection measures will only be taken if the total battery voltage actually exceeds the preset threshold and remains at that level for a certain period of time. This ensures that the triggering of the protection strategy is necessary, avoids unnecessary system interruptions, and makes the protection measures more targeted and effective.

[0057] See details Figure 2 During battery charging, a total battery voltage rising to 923V and remaining there for 65 seconds indicates a level one overvoltage; a total battery voltage rising to 936V and remaining there for 25 seconds indicates a level two overvoltage; and a total battery voltage rising to 943.8V and remaining there for 12 seconds indicates a level three overvoltage.

[0058] See details Figure 3 During battery discharge, a total voltage drop to 741V and sustained for 12 seconds indicates a total voltage overvoltage level 3; a total voltage drop to 728V and sustained for 25 seconds indicates a total voltage overvoltage level 2; and a total voltage drop to 663V and sustained for 65 seconds indicates a total voltage overvoltage level 1.

[0059] In this embodiment, the first multi-level protection strategy includes a first sub-protection strategy, a second sub-protection strategy, and a third sub-protection strategy. When the voltage of the individual battery cell meets a first preset condition, the first multi-level protection strategy is activated, including:

[0060] When the voltage of the aforementioned single cell reaches the first preset single cell voltage and is maintained for a first duration, the first sub-protection strategy is activated. The first sub-protection strategy is to control the charging and discharging power of the PCS to decrease to the first charging and discharging power.

[0061] See details Figure 2 If the voltage of a single cell rises to 3550mV and remains there for 185s, it means that the single cell voltage is over-voltage level one, and the first sub-protection strategy is activated.

[0062] See details Figure 3 If the voltage of a single cell drops to 2550mV and remains there for 185s, it means that the single cell voltage is over-voltage level one, and the first sub-protection strategy is activated.

[0063] When the voltage of the aforementioned single cell reaches the second preset single cell voltage and is maintained for a second duration, the second sub-protection strategy is activated. The second sub-protection strategy is to control the PCS charging and discharging power to decrease to the second charging and discharging power.

[0064] See details Figure 2 If the voltage of a single cell rises to 3600mV and remains there for 25 seconds, it means that the single cell voltage is over-voltage, triggering the second sub-protection strategy.

[0065] See details Figure 3If the voltage of a single cell drops to 2800mV and remains there for 25 seconds, it means that the single cell voltage is over-voltage, triggering the second sub-protection strategy.

[0066] When the voltage of the aforementioned single cell reaches the third preset single cell voltage and is maintained for the third duration, the third sub-protection strategy is activated. The third sub-protection strategy is to control the PCS charging and discharging power to decrease to the third charging and discharging power.

[0067] See details Figure 2 If the voltage of a single cell rises to 3630mV and remains there for 12 seconds, it means that the single cell voltage is over-voltage level three, and the third sub-protection strategy is activated.

[0068] See details Figure 3 If the voltage of a single cell drops to 2850mV and remains there for 12 seconds, it means that the single cell voltage is over-voltage level three, and the third sub-protection strategy is activated.

[0069] Wherein, the first preset single-cell voltage is less than the second preset single-cell voltage, the second preset single-cell voltage is less than the third preset single-cell voltage, the first duration is greater than the second duration, the second duration is greater than the third duration, the first charging / discharging power is greater than the second charging / discharging power, and the second charging / discharging power is greater than the third charging / discharging power.

[0070] The aforementioned first multi-level protection strategy, including a first sub-protection strategy, a second sub-protection strategy, and a third sub-protection strategy, has the following technical advantages:

[0071] By setting three different individual cell voltage thresholds (first, second, and third preset individual cell voltages) and corresponding charge / discharge power reduction levels (first, second, and third charge / discharge power), the system can gradually reduce the charge / discharge power of the PCS according to changes in battery voltage, rather than reducing it drastically all at once. This method effectively avoids the impact of instantaneous power changes in the battery under overvoltage conditions, protecting the battery from damage.

[0072] During charging, when the voltage of a single battery cell reaches a first preset condition, the system first activates a lighter first sub-protection strategy. Only after the voltage rises further and remains at that level for a period of time are the more stringent second and third sub-protection strategies activated sequentially. This timing control allows the battery to operate within a safe range for as long as possible, balancing overvoltage protection with battery performance.

[0073] During discharge, the voltage of a single battery cell gradually decreases, so the activation sequence is the third sub-protection strategy, the second sub-protection strategy, and then the first sub-protection strategy. Gradually relaxing the charging and discharging power restrictions during discharge allows the battery to continue operating under more relaxed discharge conditions at lower voltages, reducing excessive stress on the battery in the low-voltage range, thereby extending the overall battery life and improving the economic efficiency of the energy storage system. When the battery voltage drops to a corresponding threshold, the system can quickly identify and activate the corresponding sub-protection strategy. This immediate response mechanism effectively controls the battery's discharge rate, preventing system performance degradation due to excessively rapid discharge and improving the stability and reliability of the energy storage system. During the battery discharge phase, gradual power adjustment allows for more efficient utilization of the energy stored in the battery. Especially when the battery voltage approaches the minimum safe threshold, the first sub-protection strategy allows for lower but controllable discharge power, maximizing energy recovery and reducing energy waste.

[0074] The activation conditions (preset cell voltage and duration) of each sub-protection strategy are carefully designed to ensure that the charging and discharging power of the PCS is adjusted in time when the battery is close to overcharge, so as to avoid the battery voltage from exceeding the safe range, effectively prevent overcharging, and protect the safety and life of the battery.

[0075] The first multi-level protection strategy automatically adjusts based on the real-time status of the battery, requiring no manual intervention and providing immediate and intelligent overvoltage protection. This response speed is faster than traditional manual adjustments or single threshold triggers, improving the automation level and operational efficiency of the energy storage system.

[0076] Instead of simply stopping charging and discharging, the system can protect the battery while avoiding unnecessary energy waste, reducing energy consumption, and optimizing the overall management of the energy storage system.

[0077] A reasonable charge and discharge power adjustment strategy helps reduce the battery's operating time and frequency under extreme voltage conditions, thereby reducing battery stress, extending battery cycle life, and improving the economics of energy storage systems in the long run.

[0078] The multi-level protection strategy increases the system's safety redundancy through multi-level voltage monitoring and power adjustment. Even if a certain level of protection fails, subsequent protection strategies can still function, effectively avoiding systemic risks that may be caused by battery overvoltage.

[0079] In summary, the multi-level protection strategy can take corresponding measures according to different battery voltage stages, which not only protects the safe operation of the battery and avoids the risks of overcharging and over-discharging, but also takes into account the performance and economy of the energy storage system. It reflects the design concept of intelligence, efficiency and safety, and is an important innovation in energy storage technology in the field of battery management.

[0080] It should be noted that the first multi-level protection strategy, which includes the first sub-protection strategy, the second sub-protection strategy, and the third sub-protection strategy, is merely an exemplary scheme. The division into more or fewer sub-protection strategies based on actual needs is within the protection concept of this application.

[0081] In specific implementation, the aforementioned second multi-level protection strategy includes a fourth sub-protection strategy, a fifth sub-protection strategy, and a sixth sub-protection strategy. When the total battery voltage meets the second preset condition, the second multi-level protection strategy is activated, including:

[0082] When the total battery voltage reaches the first preset total voltage and is maintained for a fourth duration, the fourth sub-protection strategy is activated. The fourth sub-protection strategy is to control the PCS charging and discharging power to decrease to the fourth charging and discharging power.

[0083] See details Figure 2 The total battery voltage rises to 923V and remains there for 65 seconds, which means that the total voltage is over-voltage, and the fourth sub-protection strategy is activated.

[0084] See details Figure 3 The total battery voltage dropped to 663V and remained there for 65 seconds, which means that the single cell voltage was over-voltage level one, and the fourth sub-protection strategy was activated.

[0085] When the voltage of the aforementioned single cell reaches the second preset total voltage and is maintained for a fifth duration, the fifth sub-protection strategy is activated. The fifth sub-protection strategy is to control the PCS charging and discharging power to decrease to the fifth charging and discharging power.

[0086] See details Figure 2 The total battery voltage rises to 936V and remains there for 25 seconds, which means that the total voltage is over-voltage level two, and the fifth sub-protection strategy is activated.

[0087] See details Figure 3 The total battery voltage dropped to 728V and remained there for 25 seconds, which means that the total voltage was overvoltage level 2, and the fifth sub-protection strategy was activated.

[0088] When the voltage of the aforementioned single cell reaches the third preset total voltage and is maintained for a sixth duration, the sixth sub-protection strategy is activated. The sixth sub-protection strategy is to control the PCS charging and discharging power to decrease to the sixth charging and discharging power.

[0089] See details Figure 2The total battery voltage rose to 943.8V and remained there for 12 seconds, which means that the total voltage was over-voltage level three, and the sixth sub-protection strategy was activated.

[0090] See details Figure 3 The total battery voltage dropped to 741V and remained there for 12 seconds, which means that the single cell voltage was over-voltage level three, and the sixth sub-protection strategy was activated.

[0091] Wherein, the first preset total voltage is less than the second preset total voltage, the second preset total voltage is less than the third preset total voltage, the fourth duration is greater than the fifth duration, the fifth duration is greater than the sixth duration, the fourth charging / discharging power is greater than the fifth charging / discharging power, and the fifth charging / discharging power is greater than the sixth charging / discharging power.

[0092] The aforementioned second-level multi-level protection strategy, including the fourth, fifth, and sixth sub-protection strategies, achieves its technical effectiveness in the following key aspects:

[0093] By setting three incremental battery total voltage thresholds (first, second, and third preset total voltages) and sequentially activating different levels of sub-protection strategies according to the increase in battery total voltage, overvoltage protection at the system level is achieved, ensuring the safe operation of the energy storage system under high voltage conditions.

[0094] Each sub-protection strategy controls the PCS charging and discharging power to gradually decrease to a lower level (fourth, fifth, and sixth charging and discharging power), avoiding a sudden and sharp drop in charging and discharging power when the total voltage is too high, thereby reducing the impact on the battery and PCS, ensuring a smooth transition of the system and the continuous stability of battery performance.

[0095] Each sub-protection strategy has a certain duration (fourth, fifth, and sixth durations) before it is activated. This time buffering mechanism can not only effectively filter the impact of instantaneous voltage fluctuations and avoid false activation of protection strategies, but also give the system enough response time to perform more accurate power adjustment and fault diagnosis.

[0096] When the total battery voltage rises abnormally, the system can quickly identify and activate the corresponding sub-protection strategy. By gradually reducing the charging and discharging power, it provides conditions for timely fault response and safe system recovery, reducing system failures or downtime caused by excessive total voltage.

[0097] An increase in total battery voltage is usually accompanied by an increase in internal battery temperature. By promptly implementing starter protection strategies to reduce charging and discharging power, battery heat generation can be effectively controlled, thermal management of the energy storage system can be optimized, and battery performance degradation and safety hazards caused by excessive temperature can be avoided.

[0098] A multi-level protection strategy allows the system to attempt to mitigate the situation with relatively mild power adjustments when the total battery voltage rises, only taking more stringent measures when necessary. This strategy balances cost control and performance protection, avoiding increased energy consumption and reduced system efficiency caused by over-protection.

[0099] The second multi-level protection strategy provides a system-level overvoltage protection solution, which enhances the robustness of the energy storage system. Even under extreme operating conditions, it can effectively protect the battery from overvoltage damage, ensuring the stability of the system and the reliability of long-term operation.

[0100] In summary, the second multi-level protection strategy effectively addresses the abnormal rise in battery total voltage by controlling the charging and discharging power of the PCS in stages and steps. This not only ensures the safe operation of the energy storage system but also maximizes the system's performance and economic value, demonstrating significant innovation and application value in the field of energy storage technology.

[0101] The fourth duration is longer than the fifth duration, and the fifth duration is longer than the sixth duration. Specifically, the methods for determining the fourth, fifth, and sixth durations can be as follows:

[0102] First, the setting of these time thresholds needs to take into account the inherent characteristics of the battery, such as the battery's charge and discharge rate, voltage rise rate, and the battery's safe operating range at different voltages. Battery safety standards and industry specifications also guide the setting of time thresholds to ensure that protective measures can be taken in time when the battery is over-voltage, so as not to damage the battery.

[0103] These time thresholds are also related to the energy storage system's response speed to overpressure conditions. For example, 65 seconds can be considered a buffer period during which the system has enough time to detect overpressure and take primary protection measures, while 25 seconds and 12 seconds are time windows during which the system needs to take secondary and tertiary protection measures more quickly to prevent more severe overpressure conditions.

[0104] The determination of time thresholds is usually based on risk assessment and extensive experimental verification.

[0105] Analyzing historical operating data to understand battery performance under overvoltage conditions, including the rate of voltage rise and the duration of overvoltage maintenance, can help determine reasonable thresholds. For example, if historical data shows that after reaching 923V, the battery typically recovers automatically or reduces voltage through other mechanisms within 65 seconds, then 65 seconds can be considered a reasonable first-level protection trigger time.

[0106] Battery models can also be used for simulations to evaluate battery behavior under different voltage and time conditions. These simulation results can be used to optimize time thresholds, ensuring effective overvoltage protection in practical applications.

[0107] Therefore, repeated testing and optimization through experiments, simulations, and data analysis are conducted to ensure that the energy storage system can provide the most suitable protection response under different overpressure levels, while balancing system efficiency and safety. In practical applications, these time thresholds may also be dynamically adjusted based on the specific system operation and battery status. Similarly, the first, second, and third durations can also be determined using the above scheme.

[0108] It should be noted that the second multi-level protection strategy, including the fourth, fifth, and sixth sub-protection strategies, is merely an exemplary scheme. The division into more or fewer sub-protection strategies based on actual needs falls within the protection concept of this application.

[0109] See Figure 2 During charging, total voltage overvoltage occurs after individual cell overvoltage. Therefore, monitoring individual cells before total voltage is crucial. Since total voltage overvoltage typically occurs after multiple individual cells have overvoltaged, monitoring individual cells first reduces the system's response time from overvoltage detection to activation of protection measures. This timely response effectively controls the upward trend of battery voltage, preventing the battery from entering an overvoltage state and ensuring stable system operation. Early monitoring of individual cells allows the system to adjust charging strategies based on specific battery conditions, such as slowing down the charging rate or optimizing the charging sequence, achieving more refined battery management. This strategy optimization helps extend battery life and improves the performance and economy of the energy storage system. Early detection of individual cell overvoltage allows for timely measures to prevent total voltage overvoltage, reducing the need for large-scale system maintenance or battery replacement due to such events, lowering maintenance costs, and improving the operational efficiency of the energy storage system. Monitoring individual cell voltage before total voltage enables earlier intervention to avoid overvoltage conditions, thereby enhancing the overall safety of the energy storage system. Even in extreme situations, the system can prevent dangerous events such as battery thermal runaway and explosions through early warning and intervention.

[0110] See Figure 3During discharge, total voltage overvoltage occurs before individual cell overvoltage. Therefore, during discharge, total voltage can be monitored first, followed by individual cell voltage. If the total voltage does not exceed the limit during discharge, the system does not need to delve further into the individual cell level for inspection. This not only saves monitoring resources but also reduces unnecessary data processing and analysis, improving system operating efficiency. Although total voltage overvoltage occurs before individual cell overvoltage, this does not mean that the state of individual cells is unimportant. On the contrary, total voltage overvoltage is often caused by the state of individual cells. Therefore, monitoring total voltage first and then monitoring individual cells when necessary can help the system predict and prevent potential faults earlier, thereby taking appropriate measures to avoid system-wide overvoltage events. During discharge, total voltage overvoltage may indicate that the system is about to face a major safety threat, such as battery thermal runaway or fire. By detecting total voltage in real time and taking swift action, the system can control the situation before it deteriorates, greatly improving the safety and stability of the energy storage device. While ensuring that the total voltage does not exceed the limit, the system can also optimize battery balancing strategies by monitoring individual cell voltage. Maintaining the balance of individual cells within the battery pack during discharge helps improve the overall performance and lifespan of the battery pack.

[0111] In some embodiments, when the voltage of the aforementioned single-cell battery meets a first preset condition, a first multi-level protection strategy is activated, including:

[0112] When the voltage of the aforementioned single battery cell meets the first preset condition, one of the following strategies is activated: alarm strategy, charge / discharge restriction strategy, and high-voltage power-down strategy. The alarm strategy is to adjust the PCS to enter constant voltage charging mode, the charge / discharge restriction strategy is to limit the charging and discharging power of the PCS, and the high-voltage power-down strategy is to reduce the charging and discharging power of the PCS to zero.

[0113] As mentioned above, the individual battery voltages corresponding to the alarm strategy, the no-charge / no-discharge strategy, and the high-voltage power-off strategy gradually increase.

[0114] When the voltage of a single battery cell meets the first preset condition, one of the following strategies is activated: alarm strategy, charge / discharge restriction strategy, and high-voltage power-off strategy. The voltage of the single battery cell corresponding to these strategies gradually increases. The technical effects of this design are mainly reflected in the following aspects:

[0115] The alarm strategy is activated when the battery voltage just exceeds the normal range. By adjusting the PCS to enter constant voltage charging mode, it can effectively reduce the further increase of battery voltage, playing a preventive protection role and preventing the battery voltage from unnecessarily approaching a more dangerous threshold.

[0116] As the battery voltage increases, the system first activates a mild alarm strategy, then escalates to a strategy that restricts the charging and discharging power of the PCS (Power Control System), prohibiting charging and discharging. Finally, when the battery voltage reaches an extremely high-risk area, a high-voltage power-down strategy is implemented, reducing the charging and discharging power of the PCS to zero. This gradual power control mechanism allows the battery to receive gradual rather than abrupt power adjustments when facing overvoltage risks, reducing the impact on the battery and helping to extend its lifespan.

[0117] By setting different individual battery voltage thresholds to trigger different levels of protection strategies, energy storage systems can achieve more refined safety management. Alarm strategies, charge / discharge restriction strategies, and high-voltage power-off strategies constitute a gradient protection system ranging from minor warnings to emergency power outages, ensuring appropriate safety responses at different voltage levels.

[0118] Since different strategies correspond to gradually increasing individual cell voltages, this design allows the system to flexibly adjust its response measures according to the specific battery voltage conditions, and can respond promptly and appropriately to both slight voltage fluctuations and severe overvoltage conditions.

[0119] Early intervention with alarm and charge / discharge restriction policies can prevent the battery voltage from reaching the level of high voltage, thus reducing hardware damage caused by battery overvoltage, lowering maintenance and repair costs, and reducing system downtime.

[0120] For users, this layered protection strategy provides clear warning signals, allowing them to understand changes in battery status and have enough reaction time to take action, avoiding the inconvenience and losses caused by sudden power outages and improving the overall user experience.

[0121] In this embodiment of the application, the above method further includes:

[0122] Based on the individual cell voltage and total battery voltage obtained in the current time period, predict the predicted individual cell voltage and total battery voltage at the future target time point.

[0123] Based on the predicted cell voltage, a first pre-protection strategy is activated. The first pre-protection strategy includes at least one of the following: pre-reducing PCS charging and discharging power, pre-enhancing cooling, and optimizing load charging distribution.

[0124] Based on the predicted cell voltage, a second pre-protection strategy is activated, which includes at least one of the following: pre-reducing the charging and discharging power of the PCS, pre-cutting off the charging branch, and pre-fault isolation.

[0125] In this embodiment, by predicting the predicted single-cell voltage and predicted total battery voltage at a future target time point, and activating the first and second pre-protection strategies based on these prediction results, the technical effects are as follows:

[0126] Predictions based on current battery voltage and total voltage data can identify potential upward trends in battery voltage and total voltage in advance, allowing for the activation of corresponding proactive protection strategies. This proactive safety control, compared to traditional reactive measures, can more effectively prevent overvoltage events and ensure the safe operation of the energy storage system.

[0127] The first pre-protection strategy, which involves pre-reducing the PCS charging and discharging power, intelligently adjusts the charging and discharging power based on predicted individual cell voltages to prevent the battery voltage from reaching or exceeding a threshold in the future. This dynamic adjustment mechanism improves the system's intelligent management level, enabling it to better adapt to changes in battery state and maintain the battery within a safe operating range.

[0128] Pre-cooling enhancement strategies can activate or strengthen the cooling system before overheating or voltage rise is predicted, effectively controlling battery temperature and preventing performance degradation or safety issues caused by high temperatures. This strategy optimizes thermal management, extends battery life, and improves the overall performance of the energy storage system.

[0129] Optimized load charging distribution can intelligently allocate the charging and discharging loads of different battery modules based on the predicted battery voltage distribution, ensuring overall system voltage balance and preventing some battery modules from reaching overvoltage prematurely, thereby improving the efficiency and reliability of the energy storage system.

[0130] The second pre-protection strategy, which includes pre-cutting off charging branches and pre-fault isolation, can take isolation measures in advance before the battery voltage is predicted to rise abnormally. This can disconnect battery cells that may have faults or overvoltage risks, thus avoiding their impact on the stability and safety of the entire system and enhancing the system's self-protection capabilities.

[0131] By implementing pre-protection strategies, a series of measures can be taken to intervene before the battery voltage and total voltage reach an emergency state, reducing the need for emergency shutdown or high-voltage power-off, lowering the probability of sudden failures, and improving the system's continuous operation capability and user satisfaction.

[0132] The implementation of pre-protection strategies not only avoids overcharging and over-discharging of batteries, but also enables more efficient use of resources within the energy storage system by optimizing load charging distribution and enhancing cooling, thereby improving the overall energy conversion efficiency and the economic efficiency of system operation.

[0133] Embodiments of this application provide an energy storage system, such as Figure 4As shown, it includes:

[0134] Multiple battery clusters, each of which comprises multiple individual cells connected in series, wherein an individual cell is... Figure 4 Battery PACK in the middle;

[0135] Multiple battery management units are electrically connected to each of the aforementioned individual battery cells; see [link to battery management unit documentation]. Figure 4 The BMU (Battery Management Unit) in the middle;

[0136] Multiple battery control units, one of the battery control units being connected to multiple battery management units via a bus, the number of battery control units being equal to the number of battery clusters;

[0137] See battery control unit Figure 4 The BCU (Battery Control Unit) in the middle;

[0138] A network switch and a system control unit, wherein each of the aforementioned battery control units is connected to the aforementioned network switch via a bus, and the aforementioned network switch is connected to the aforementioned system control unit via a bus;

[0139] See system control unit Figure 4 The SCU (System Control Unit) in the middle;

[0140] An energy storage converter is connected to the aforementioned system control unit via a bus and has a charging branch connected to the aforementioned individual battery.

[0141] See energy storage converter Figure 4 PCS (Power Conversion System) in the middle;

[0142] The battery management unit (BMU) is used to acquire the voltage of individual cells. The battery control unit is used to activate a first multi-level protection strategy when the voltage of the individual cells meets a first preset condition. The first multi-level protection strategy includes adopting different charge and discharge protection strategies when the voltage of the individual cells reaches different preset individual cell voltages. The energy storage converter (PCS) is used to monitor the total battery voltage and to activate a second multi-level protection strategy when the total battery voltage meets a second preset condition. The second multi-level protection strategy includes adopting different charge and discharge protection strategies when the total battery voltage reaches different preset total voltages.

[0143] based on Figure 4In the energy storage system, each battery management unit (BMU) is directly connected to the individual battery and can obtain the battery voltage in real time. This enables precise monitoring of the status of each battery in the energy storage system. Compared with centralized monitoring systems, distributed monitoring can identify and respond to local overvoltage events more quickly, improving the system's response speed and overall monitoring accuracy.

[0144] The Battery Control Unit (BCU) and multiple Battery Management Units (BMUs) form a second-level control layer, capable of aggregating data from the BMUs and activating a first multi-level protection strategy based on preset conditions. The Power Storage Converter (PCS) resides at a higher control level, responsible for monitoring the overall system status and total battery voltage, and enabling global control of the multi-level overvoltage protection strategy. This hierarchical control structure allows the system to monitor battery status microscopically, coordinate battery cluster operation mesoscopically, and control the safety and efficiency of the entire energy storage system macroscopically, forming an intelligent, adaptive control system.

[0145] By setting preset individual cell voltages and preset total voltages at different levels, the system can respond to subtle changes in battery state, rather than waiting until the problem becomes severe. This not only effectively prevents overcharging and over-discharging, but also optimizes the battery charging and discharging process by dynamically adjusting the charging and discharging power, reducing energy loss and improving the overall energy efficiency of the system.

[0146] The system adopts a modular design concept, and the arrangement of multiple battery clusters, battery management units, and control units makes the system easy to expand and maintain. When adding a new battery cluster, only the number of battery management units and control units needs to be increased accordingly, without changing the overall architecture. This greatly enhances the system's design flexibility and future expansion potential.

[0147] In addition to the protection mechanisms of PCS and BCU, the system also has an SCU as a higher-level controller, which can comprehensively monitor the operating status of the entire network and take further security measures when necessary, such as activating a second multi-level protection strategy. This multi-layered defense mechanism provides additional security redundancy; even if a control layer fails, the higher-level controller can still take over and ensure the safe operation of the system.

[0148] Through early warning and tiered response, the system can promptly detect and address overvoltage issues, reducing the probability of battery failure. Simultaneously, the clearly defined hierarchical control structure and redundancy design improve the overall reliability of the energy storage system, reducing the risk of system collapse due to the failure of a single component.

[0149] Additional notes are as follows: Figure 4 The battery management unit (BMU) in the method embodiment is used to execute all schemes related to the first multi-level protection strategy, and will not be described again;

[0150] Additional notes are as follows: Figure 4 The energy storage converter PCS in the method embodiment is used to execute all schemes related to the second multi-level protection strategy, and will not be described again;

[0151] In addition, the aforementioned energy storage system also includes an energy management system, which is connected to the system control unit via a bus. See the energy management system section for details. Figure 4 In the EMS (Energy Management System), the SCU is connected to the EMS via a bus. The SCU is responsible for controlling the various components inside the energy storage system, while the EMS manages and optimizes the energy storage system from a higher level. The two work together to enable the energy storage system to not only operate safely and reliably, but also respond efficiently and intelligently to the needs of the external power network and achieve its best performance.

[0152] Additionally, see Figure 4 The aforementioned energy storage system also includes: multiple high-voltage boxes, each containing one of the aforementioned battery control units and one charging branch. The charging branch includes a branch circuit breaker, a contactor, and a main voltage fuse.

[0153] exist Figure 5 In the energy storage system shown, the design of multiple high-voltage boxes and their internal charging circuits and battery control units (BCUs) collectively enhance the system's technical performance in the following aspects:

[0154] As an independent modular unit, each high-voltage box contains a BCU and a corresponding charging branch. This design facilitates the installation, maintenance, and expansion of the system. The number of high-voltage boxes can be flexibly increased or decreased according to needs to adapt to energy storage projects of different scales.

[0155] Each charging branch in the high-voltage box is equipped with a branch circuit breaker and a main voltage fuse, which can quickly cut off the circuit in case of overload, short circuit or abnormal voltage, preventing electrical fires and other safety accidents, and providing multiple safety protections.

[0156] Through the tight integration of the BCU with the charging branch, fine-grained charge and discharge management of each battery cell or battery cluster can be achieved, including real-time monitoring of battery status, adjustment of charging strategy, and avoidance of overcharging and over-discharging, thereby effectively extending battery life and improving energy storage efficiency.

[0157] When a battery or charging branch in a high-voltage box fails, the fault can be isolated by disconnecting the branch circuit breaker of that box, without affecting the operation of other high-voltage boxes, thus improving the overall fault tolerance and recovery speed of the system.

[0158] The charging circuit controls the battery connection via a contactor, which can reduce unnecessary energy consumption. At the same time, intelligent control of the charging process improves the efficiency of energy conversion and storage, reducing energy waste.

[0159] Modular design facilitates the location and replacement of faulty components, reducing maintenance workload and downtime, and improving system availability and maintenance efficiency.

[0160] In summary, through the modular design of the high-voltage box and the precise configuration of the charging branches, the energy storage system achieves higher safety, scalability, management efficiency, and energy utilization efficiency. It also improves the system's fault response capability and ease of maintenance, representing a significant advancement in the field of energy storage technology.

[0161] Embodiments of this application provide an energy storage system, such as Figure 5 As shown, it includes:

[0162] Multiple battery clusters, each of which comprises multiple individual cells connected in series, see individual cells for details. Figure 5 Medium battery pack;

[0163] Multiple battery management units are electrically connected to each of the aforementioned individual battery cells; see [link to battery management unit documentation]. Figure 5 The BMU (Battery Management Unit) in the middle;

[0164] Multiple energy storage converters, each of which includes a battery control unit, a charging branch, and an auxiliary control unit, wherein one battery control unit is connected to multiple battery management units via a bus, and the number of battery control units is equal to the number of battery clusters; see energy storage converters. Figure 5 PCS in;

[0165] Auxiliary control unit (see) Figure 5 ARM+DSP in

[0166] See battery control unit Figure 5 The BCU (Battery Control Unit) in the middle;

[0167] A network switch and a system control unit, wherein each of the aforementioned energy storage converters is connected to the aforementioned network switch via a bus, and the aforementioned network switch is connected to the aforementioned system control unit via a bus;

[0168] See system control unit Figure 5 The SCU (System Control Unit) in the middle;

[0169] The battery management unit (BMU) is used to acquire the voltage of individual cells, and the battery control unit (BCU) is used to activate a first multi-level protection strategy when the voltage of the individual cells meets a first preset condition. The first multi-level protection strategy includes adopting different charge and discharge protection strategies when the voltage of the individual cells reaches different preset individual cell voltages. The auxiliary control unit is used to monitor the total battery voltage and to activate a second multi-level protection strategy when the total battery voltage meets a second preset condition. The second multi-level protection strategy includes adopting different charge and discharge protection strategies when the total battery voltage reaches different preset total voltages.

[0170] The energy storage system provided in this application embodiment achieves refined management of battery status through its unique network architecture and hierarchical protection strategy. Its technical effects can be summarized as follows:

[0171] Each individual cell has a corresponding Battery Management Unit (BMU) for voltage monitoring. This one-to-one monitoring method improves data accuracy and response speed, ensuring that the system can promptly detect and handle overvoltage conditions in individual cells.

[0172] In the system design, the Battery Control Unit (BCU), the Auxiliary Control Unit (ARM+DSP), and the System Control Unit (SCU) constitute a multi-layered control architecture from local to global. The BCU is responsible for the first level of protection, directly controlling the charging and discharging power; the ARM+DSP, as part of the PCS, monitors the total battery voltage and executes the second level of protection strategy; the SCU acts as the upper-level controller, performing global coordination and emergency handling. This structure not only improves the system's response speed but also increases its redundancy and stability.

[0173] The introduction of first-level and second-level multi-level protection strategies enables the system to take different levels of protection measures according to the severity of overvoltage. This intelligent hierarchical protection not only improves the safety factor but also avoids unnecessary over-protection, maintaining the efficient operation of the system.

[0174] Through close cooperation between the BMU and BCU, the system can adjust the charging and discharging strategy at the initial stage of overvoltage, avoiding energy waste and shortened battery life caused by overvoltage. The auxiliary control unit (ARM+DSP) in the PCS can monitor the total battery voltage and adjust the PCS's operating mode in a timely manner, ensuring a more rational energy distribution and improving energy utilization efficiency throughout the energy storage system.

[0175] Each battery cluster is equipped with an independent energy storage converter (PCS), as well as a battery control unit (BCU) and an auxiliary control unit (ARM+DSP). This modular design makes the system easy to expand horizontally. At the same time, due to the independence of each PCS, BCU and ARM+DSP, the failure of a single component will not affect the entire system, reducing maintenance difficulty and downtime.

[0176] By connecting all BCUs and SCUs through a network switch, a highly efficient and stable communication network is formed. This network design improves data transmission efficiency, and at the same time, because data is transmitted on the bus, communication security is enhanced, reducing system risks caused by communication failures.

[0177] The system's flexible architecture allows it to adapt to energy storage needs of different scales. Whether it is a small home energy storage system or a large industrial energy storage facility, it can achieve efficient and safe energy storage and conversion by adjusting the number of battery clusters and the corresponding PCS and BCU configurations.

[0178] In summary, the energy storage system of this application significantly improves the safety, operating efficiency, and flexibility of energy storage systems through its hierarchical protection and control structure, intelligent graded overvoltage protection mechanism, modular design, optimized energy management, and powerful communication capabilities, providing new ideas and solutions for the development of energy storage technology.

[0179] Additional notes are as follows: Figure 5 The battery management unit (BMU) in the method embodiment is used to execute all schemes related to the first multi-level protection strategy, and will not be described again;

[0180] Additional notes are as follows: Figure 5 The battery control unit (BCU) in the method embodiment is used to execute all schemes related to the second multi-level protection strategy, and will not be described again;

[0181] The aforementioned energy storage system also includes an energy management system, which is connected to the system control unit via a bus. See the energy management system section for details. Figure 5 The EMS (Energy Management System) is integrated with the SCU (System Cooling Unit) to monitor the health of the energy storage system in real time, prevent potential failures, ensure the system operates safely and reliably, and reduce energy losses or safety incidents caused by system instability. The EMS collects and analyzes large amounts of operational data, providing data support for system maintenance, upgrades, and fault prediction, helping operators make data-driven decisions, and further improving system performance and operational efficiency.

[0182] The aforementioned energy storage system also includes: multiple battery cabinets, the number of which is equal to the number of battery clusters;

[0183] Among them, one of the aforementioned battery clusters, one of the aforementioned energy storage converters, the aforementioned network switch, and the aforementioned system control unit are integrated in the target battery cabinet, and the aforementioned target battery cabinet is one of the multiple aforementioned battery cabinets. A non-target battery cabinet integrates one of the aforementioned battery clusters and one of the aforementioned energy storage converters.

[0184] Integrating a battery cluster, a PCS, a network switch, and an SCU into a single target battery cabinet gives the energy storage system a high degree of modularity and standardization. This design facilitates system design, production, transportation, and field deployment, significantly reducing installation and commissioning costs, while also benefiting subsequent system maintenance and upgrades.

[0185] The non-target battery cabinet integrates only one battery cluster and one PCS, while the critical control and communication functions are handled by the SCU and network switch in the target battery cabinet. This architecture simplifies the internal complexity of the system, reduces the delay of control signals, and improves the system's response speed and overall efficiency.

[0186] Because the number of battery cabinets and battery clusters is matched, more non-target battery cabinets can be quickly added according to project needs, enabling flexible expansion of system capacity. Meanwhile, since the target battery cabinet integrates critical control and communication equipment, system expansion does not require redesigning the core architecture, simplifying the expansion process.

[0187] The integrated battery cabinet design makes the connection of critical components more secure, reducing failures caused by poor wiring or signal interference. The independence of each battery cabinet also means that even if a problem occurs in one battery cabinet, it will not immediately affect the operation of the entire system, enhancing the system's fault tolerance and fault isolation capabilities.

[0188] By sharing the SCUs and network switches in the target battery cabinet, non-target battery cabinets do not need to be equipped with these devices separately, which saves costs and optimizes space layout. Centralized control and communication equipment also facilitates unified management and reduces the investment of maintenance manpower and resources.

[0189] The aforementioned energy storage converter also includes a DC-AC converter, electrically connected to the aforementioned charging branch. See the DC-AC converter section. ​ The DC / AC charging branch in the circuit includes a fuse, a contactor module KM, and a circuit breaker QS. Specifically, one of the aforementioned charging branches includes: a circuit breaker QS, a contactor module KM, and a fuse connected in series. One end of the circuit breaker is electrically connected to the individual battery cell, and one end of the fuse is electrically connected to one end of the DC / AC converter.

[0190] The DC / AC converter (i.e., direct current to alternating current converter) is an important component of the energy storage converter (PCS). It is electrically connected to the fuse, contactor module KM, and circuit breaker QS in the charging branch. Its technical advantages are mainly reflected in the following aspects:

[0191] A DC / AC converter can convert direct current (DC) to alternating current (AC) and vice versa. In energy storage systems, it is responsible for converting the DC power stored in the battery into AC power for use by the power grid, or converting the AC power from the grid into DC power suitable for battery charging during charging, thus realizing bidirectional flow and conversion of energy.

[0192] The integration of fuse, contactor module KM, and circuit breaker QS provides multiple protection mechanisms in the charging branch, which can quickly disconnect the circuit in case of overcurrent, short circuit or abnormal voltage, protect the DC / AC converter and battery from damage, and significantly improve the overall safety and reliability of the energy storage system.

[0193] The contactor module KM plays a crucial control role in the charging and discharging process. It can precisely control the charging and discharging state according to the instructions of the system control unit (SCU), ensuring the efficient operation of the PCS, while avoiding overcharging and over-discharging of the battery and extending the battery's lifespan.

[0194] DC / AC converters, through advanced power electronics technology, can achieve high-efficiency energy conversion during charging and discharging, reducing energy loss during the conversion process and improving the energy utilization efficiency of energy storage systems.

[0195] DC / AC converters can adjust the frequency and phase of the output AC power according to the real-time demand of the power grid, ensuring the synchronous operation of the energy storage system with the power grid and improving the response speed and adaptability of the energy storage system to the power grid demand.

[0196] The introduction of the circuit breaker QS enables rapid system recovery in the event of a fault. Once an anomaly, such as overvoltage or overcurrent, is detected, the QS can immediately disconnect the circuit to prevent the fault from spreading. At the same time, it can be safely reconnected after the fault is cleared, reducing system downtime and improving system availability and fault recovery capabilities.

[0197] The presence of fuses, contactor modules, and circuit breakers provides safety assurance during system maintenance or operation, ensuring the safety of maintenance personnel and the system during operation and reducing operational risks.

[0198] In summary, the combination of DC / AC converters and protection components in the charging branch not only improves the energy conversion efficiency and flexibility of energy storage systems but also enhances their safety and reliability, making it an indispensable key technology in energy storage systems. The application of this technology is of great significance for achieving efficient and stable operation of energy storage systems in smart grids.

[0199] The aforementioned energy storage system also includes a dehumidifier, a liquid cooler, a temperature and humidity sensor, and a water immersion sensor, all of which communicate with the battery control unit via a bus. The battery control unit assigns addresses to the dehumidifier, liquid cooler, temperature and humidity sensor, and water immersion sensor.

[0200] In the aforementioned energy storage system, the dehumidifier, liquid cooler, temperature and humidity sensor, water immersion sensor, and battery control unit (BCU) are integrated via bus communication, with the BCU assigning addresses. This brings a series of technical benefits:

[0201] Temperature and humidity sensors and water immersion sensors can monitor the temperature, humidity and water immersion status inside the battery cabinet in real time. Based on this data, the BCU automatically controls the operation of the dehumidifier and liquid cooler to ensure that the battery works in a suitable environment and avoid battery performance degradation or safety hazards caused by poor environmental conditions.

[0202] Liquid coolers provide precise temperature control, adjusting the cooling strategy according to the actual operating conditions of the battery to maintain the battery pack within the optimal operating temperature range. This is crucial for extending battery life and improving energy conversion efficiency.

[0203] The water immersion sensor can detect liquid leaks in the battery cabinet in a timely manner. Once an abnormality is detected, it can immediately notify the BCU to take action, such as activating the alarm or cutting off the power supply, effectively preventing serious accidents such as electrical short circuits or fires.

[0204] As the central control unit, the BCU is responsible for communicating with all relevant devices and assigning them addresses, thereby enabling centralized management and control of environmental control equipment, simplifying the system architecture, improving management efficiency, and reducing the difficulty of operation and maintenance.

[0205] By continuously collecting environmental data and combining it with battery charging and discharging data, the BCU can analyze and predict potential maintenance needs in advance, such as performance degradation of the cooling system or filter blockage in the dehumidifier, and thus carry out targeted maintenance to avoid the impact of sudden failures.

[0206] By intelligently controlling the operation of the dehumidifier and liquid chiller, unnecessary energy consumption is avoided, energy efficiency is achieved, and the overall operating cost of the system is reduced.

[0207] The BCU records and analyzes data from temperature and humidity sensors and water immersion sensors, providing a basis for system performance evaluation and optimization. It also plays an important role in fault analysis, helping to identify the source of the fault and improve the accuracy of fault response and handling.

[0208] By using bus communication, not only is the coordination between components within the system enhanced, but the system's compatibility is also improved, making it easier to add or update environmental control equipment in the future to meet ever-changing energy storage needs.

[0209] By tightly integrating dehumidifiers, liquid chillers, temperature and humidity sensors, and water immersion sensors into the energy storage system and intelligently managing them through the BCU, this design effectively improves the system's thermal management capabilities, operational safety, and maintenance efficiency, representing an innovative application in the field of environmental control within energy storage technology.

[0210] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of this application. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A method for charging and discharging a battery of an energy storage system, characterized by, Comprising: Monitoring single battery voltage and battery total pressure; Step 1: in the case that the single battery voltage meets the first preset condition, starting the first multi-level protection strategy, the first multi-level protection strategy including different charging and discharging protection strategies when the single battery voltage reaches different preset single voltages, wherein if the single battery voltage reaches any of the preset single voltages and maintains for a corresponding time length, it indicates that the single battery voltage meets the first preset condition; Step 2: in the case that the battery total pressure meets the second preset condition, starting the second multi-level protection strategy, the second multi-level protection strategy including different charging and discharging protection strategies when the battery total pressure reaches different preset total pressures, wherein if the battery total pressure reaches any of the preset total pressures and maintains for a corresponding time length, it indicates that the battery total pressure meets the second preset condition, the time length maintained by the single battery voltage and the time length maintained by the battery total pressure are related to the inherent characteristics of the battery and the response speed of the energy storage system to overvoltage conditions, the inherent characteristics of the battery including the charging and discharging rate of the battery, the voltage rising speed, and the working safety range of the battery at different voltages; Further comprising: In the charging process, the total pressure overvoltage occurs after the single battery overvoltage, the step 1 is executed first and then the step 2 is executed to reduce the response time from detecting overvoltage to starting protection measures, the total pressure overvoltage is the battery total pressure overvoltage, and the single battery overvoltage is the single battery voltage overvoltage; In the discharging process, the total pressure overvoltage occurs before the single battery overvoltage, the step 2 is executed first, and if the battery total pressure is not overvoltage, the step 1 is not executed; According to the single battery voltage and the battery total pressure obtained in the current time period, predicting the predicted single battery voltage and the predicted battery total pressure at the future target time point; According to the predicted single battery voltage, starting the first pre-protection strategy, the first pre-protection strategy including at least one of pre-reducing PCS charging and discharging power, pre-enhancing refrigeration, and optimizing load charging distribution; According to the predicted single battery voltage, starting the second pre-protection strategy, the second pre-protection strategy including at least one of pre-reducing the PCS charging and discharging power, pre-cutting the charging branch, and pre-fault isolation.

2. The battery charge-discharge method of an energy storage system according to claim 1, wherein The first multi-level protection strategy includes a first sub-protection strategy, a second sub-protection strategy, and a third sub-protection strategy, and in the case that the single battery voltage meets the first preset condition, starting the first multi-level protection strategy, including: In the case that the single battery voltage reaches the first preset single voltage and maintains for a first time length, starting the first sub-protection strategy, the first sub-protection strategy being to control the PCS charging and discharging power to drop to a first charging and discharging power; In the case that the single battery voltage reaches the second preset single voltage and maintains for a second time length, starting the second sub-protection strategy, the second sub-protection strategy being to control the PCS charging and discharging power to drop to a second charging and discharging power; In a case where the single battery voltage reaches a third preset single battery voltage and is maintained for a third time length, a third sub-protection strategy is started, and the third sub-protection strategy is to control the PCS charging and discharging power to drop to a third charging and discharging power. The first preset single battery voltage is less than the second preset single battery voltage, the second preset single battery voltage is less than a third preset single battery voltage, the first time length is greater than the second time length, the second time length is greater than the third time length, the first charging and discharging power is greater than the second charging and discharging power, and the second charging and discharging power is greater than the third charging and discharging power.

3. The battery charge-discharge method of an energy storage system according to claim 1, wherein, The second multi-level protection strategy includes a fourth sub-protection strategy, a fifth sub-protection strategy and a sixth sub-protection strategy, and in a case where the total battery voltage meets a second preset condition, the second multi-level protection strategy is started, including: In a case where the total battery voltage reaches a first preset total voltage and is maintained for a fourth time length, a fourth sub-protection strategy is started, and the fourth sub-protection strategy is to control the PCS charging and discharging power to drop to a fourth charging and discharging power. In a case where the single battery voltage reaches a second preset total voltage and is maintained for a fifth time length, a fifth sub-protection strategy is started, and the fifth sub-protection strategy is to control the PCS charging and discharging power to drop to a fifth charging and discharging power. In a case where the single battery voltage reaches a third preset total voltage and is maintained for a sixth time length, a sixth sub-protection strategy is started, and the sixth sub-protection strategy is to control the PCS charging and discharging power to drop to a sixth charging and discharging power. The first preset total voltage is less than the second preset total voltage, the second preset total voltage is less than a third preset total voltage, the fourth time length is greater than the fifth time length, the fifth time length is greater than the sixth time length, the fourth charging and discharging power is greater than the fifth charging and discharging power, and the fifth charging and discharging power is greater than the sixth charging and discharging power.

4. The battery charge-discharge method of an energy storage system according to claim 1, wherein In a case where the single battery voltage meets a first preset condition, a first multi-level protection strategy is started, including: In a case where the single battery voltage meets a first preset condition, one of an alarm strategy, a forbidden charging and discharging strategy and a high-voltage power-off strategy is started, The alarm strategy is to adjust the PCS to enter a constant-voltage charging mode, the forbidden charging and discharging strategy is to limit the PCS charging and discharging power, and the high-voltage power-off strategy is to reduce the PCS charging and discharging power to zero.

5. An energy storage system characterized by, Including: A plurality of battery clusters, any of the battery clusters including a plurality of single batteries connected in series; A plurality of battery management units, each of the battery management units being electrically connected with a single battery; A plurality of battery control units, one of the battery control units being connected with a plurality of the battery management units through a bus, the number of the battery control units being equal to the number of the battery clusters; One network switch and one system control unit, each of the battery control units being connected with the network switch through a bus, the network switch being connected with the system control unit through a bus; One energy storage converter connected with the system control unit through a bus, and a charging branch being connected between the energy storage converter and the single battery. The battery management unit is configured to acquire the single battery voltage, and the battery control unit is configured to perform step 1: starting a first multi-level protection strategy when the single battery voltage meets a first preset condition, the first multi-level protection strategy including that different charge-discharge protection strategies are adopted when the single battery voltage reaches different preset single battery voltages, wherein if the single battery voltage reaches any of the preset single battery voltages and maintains for a corresponding time length, it is indicated that the single battery voltage meets the first preset condition. The energy storage converter is configured to monitor the total battery voltage, and is configured to perform step 2: starting a second multi-level protection strategy when the total battery voltage meets a second preset condition, the second multi-level protection strategy including that different charge-discharge protection strategies are adopted when the total battery voltage reaches different preset total voltages, wherein if the total battery voltage reaches any of the preset total voltages and maintains for a corresponding time length, it is indicated that the total battery voltage meets the second preset condition, the time length maintained by the single battery voltage and the time length maintained by the total battery voltage are related to inherent characteristics of the battery and a response speed of the energy storage system to overvoltage, the inherent characteristics of the battery including a charge-discharge rate of the battery, a voltage rising speed, and a working safety range of the battery at different voltages. In the charging process, the total voltage overvoltage occurs after the single battery overvoltage, the battery control unit performs the step 1 first, and then the energy storage converter performs the step 2 to reduce the response time from detecting overvoltage to starting protection measures, the total voltage overvoltage is the total battery voltage overvoltage, and the single battery overvoltage is the single battery voltage overvoltage. In the discharging process, the total voltage overvoltage occurs before the single battery overvoltage, the energy storage converter performs the step 2 first, and if the total battery voltage is not overvoltage, the battery control unit does not perform the step 1.

6. The energy storage system of claim 5, wherein, The energy storage system further comprises: An energy management system connected to the system control unit through a bus.

7. The energy storage system of claim 5, wherein, The energy storage system further comprises: A plurality of high-voltage boxes, one of the high-voltage boxes being distributed with one of the battery control units and one of the charging branches.

8. An energy storage system characterized by, Comprising: A plurality of battery clusters, any of the battery clusters comprising a plurality of single batteries connected in series; A plurality of battery management units, each of the battery management units being electrically connected to one of the single batteries in a one-to-one correspondence; A plurality of energy storage converters, any of the energy storage converters comprising one of the battery control units, one of the charging branches, and one of the auxiliary control units, one of the battery control units being connected to a plurality of the battery management units through a bus, the number of the battery control units being equal to the number of the battery clusters; A network switch and a system control unit, each of the energy storage converters being connected to the network switch through a bus, and the network switch being connected to the system control unit through a bus; The battery management unit is configured to acquire the single battery voltage, and the battery control unit is configured to perform step 1: starting a first multi-level protection strategy when the single battery voltage meets a first preset condition, the first multi-level protection strategy including adopting different charge and discharge protection strategies when the single battery voltage reaches different preset single battery voltages, wherein if the single battery voltage reaches any of the preset single battery voltages and maintains for a corresponding time length, it is indicated that the single battery voltage meets the first preset condition. The auxiliary control unit is configured to monitor the total battery voltage and perform step 2: starting a second multi-level protection strategy when the total battery voltage meets a second preset condition, the second multi-level protection strategy including adopting different charge and discharge protection strategies when the total battery voltage reaches different preset total voltages; wherein if the total battery voltage reaches any of the preset total voltages and maintains for a corresponding time length, it is indicated that the total battery voltage meets the second preset condition, and the time length maintained by the single battery voltage and the time length maintained by the total battery voltage are related to the inherent characteristics of the battery and the response speed of the energy storage system to overvoltage conditions, the inherent characteristics of the battery including the charge and discharge rate of the battery, the voltage rise speed, and the working safety range of the battery at different voltages. During the charging process, the total voltage overvoltage occurs after the single battery overvoltage, the battery control unit performs the step 1 first, and then the auxiliary control unit performs the step 2 to reduce the response time from detecting overvoltage to starting protection measures, the total voltage overvoltage is the total battery voltage overvoltage, and the single battery overvoltage is the single battery voltage overvoltage. During the discharging process, the total voltage overvoltage occurs before the single battery overvoltage, the auxiliary control unit performs the step 2 first, and if the total battery voltage is not overvoltage, the battery control unit does not perform the step 1.

9. The energy storage system of claim 8, wherein, The energy storage system further comprises: An energy management system connected to the system control unit through a bus.

10. The energy storage system of claim 8, wherein, The energy storage system further comprises: A plurality of battery cabinets, the number of the battery cabinets being equal to the number of the battery clusters; Wherein, one of the battery clusters, one of the energy storage converters, the network switch and the system control unit are integrated in a target battery cabinet, the target battery cabinet being one of the plurality of battery cabinets, and one of the battery clusters and one of the energy storage converters are integrated in a non-target battery cabinet.

11. The energy storage system of claim 8, wherein, The energy storage converter further comprises: A DCAC converter electrically connected to the charging branch.

12. The energy storage system of claim 11, wherein, One of the charging branches comprises: A circuit breaker, a contactor module and a fuse connected in series, one end of the circuit breaker being electrically connected to the single battery, and one end of the fuse being electrically connected to one end of the DCAC converter.

13. The energy storage system of claim 8, wherein, The energy storage system further comprises: A dehumidifier, a liquid cooler, a temperature and humidity sensor, and a water immersion sensor, which are respectively in communication with the battery control unit through a bus. The energy storage system further comprises: A dehumidifier, a liquid cooler, a temperature and humidity sensor, and a water immersion sensor, which are respectively in communication with the battery control unit through a bus.

Images