Energy storage system battery cell fault monitoring and processing method and energy storage system

Abstract

The present invention provides a method for monitoring and handling cell faults in an energy storage system and an energy storage system. The method for monitoring and handling cell faults in an energy storage system includes: obtaining the voltage change value ΔVi and the temperature change value ΔTi of each cell i; comparing the voltage change values ​​ΔVi, extracting the maximum voltage change value ΔVmax and the first cell number k corresponding to the maximum voltage change value ΔVmax; comparing the temperature change values ​​ΔTi, extracting the maximum temperature change value ΔTmax and the second cell number K corresponding to the maximum temperature change value ΔTmax; judging whether a battery cell is faulty based on the maximum voltage change value ΔVmax, the maximum temperature change value ΔTmax, the first cell number k, and the second cell number K, and making the battery cell operate normally or power off the battery cell or reducing the power of the battery cell. The method for monitoring and handling cell faults in an energy storage system of the technical solution of the present invention can improve the accuracy of fault judgment and improve the stability and safety of the operation of the energy storage system.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage batteries, and in particular to a method for monitoring and processing battery cell faults in an energy storage system and an energy storage system. Background Art

[0002] Battery safety has always been a major concern for users. Energy storage systems are typically composed of thousands of small batteries, the smallest of which are called "cells." Battery safety is often determined by these cells, making it essential to monitor the status of each cell and take immediate action if an abnormality is about to occur.

[0003] The inventors are aware of a method and system for online battery status assessment that can achieve instant fault prediction. On the one hand, it only monitors the battery status by voltage. This single monitoring method makes it difficult to accurately determine the specific fault behavior of the battery. On the other hand, the above technical solution does not provide a specific method for handling the fault. In many cases, energy storage batteries will take emergency measures, namely, shutting down the entire device. However, if only shutting down the device is adopted when a fault occurs, there will be many safety hazards. Summary of the Invention

[0004] The main purpose of the present invention is to provide a method for monitoring and handling battery cell faults in an energy storage system and an energy storage system. The method for monitoring and handling battery cell faults in the energy storage system can improve the accuracy of fault judgment and improve the stability and safety of the energy storage system operation.

[0005] To achieve the above-mentioned object, the present invention provides a method for monitoring and handling battery cell failures in an energy storage system. The energy storage system includes multiple battery units, each of which includes multiple battery cells. The battery cells are numbered i, where i can be 1 to n and n is an integer greater than 1. The method for monitoring and handling battery cell failures in the energy storage system includes: obtaining a voltage change value ΔVi and a temperature change value ΔTi of each battery cell i within an acquisition period t; comparing each voltage change value ΔVi, extracting a maximum voltage change value ΔVmax and a first battery cell number k corresponding to the maximum voltage change value ΔVmax; comparing each temperature change value ΔTi, extracting a maximum temperature change value ΔTmax and a second battery cell number K corresponding to the maximum temperature change value ΔTmax; and determining whether the battery cell is faulty based on the maximum voltage change value ΔVmax, the maximum temperature change value ΔTmax, the first battery cell number k, and the second battery cell number K, and processing steps of enabling the battery cell to operate normally, power off the battery cell, or reduce the power of the battery cell.

[0006] Furthermore, the processing steps include a first judgment step of determining whether the first battery cell number k and the second battery cell number K are equal. If so, a judgment step of determining whether the battery cell is a faulty battery is executed. If not, a first execution step of making the battery cell operate normally or power off the battery cell or reducing the power of the battery cell is executed based on the maximum temperature change value ΔTmax and the maximum voltage change value ΔVmax.

[0007] Furthermore, after the determination step, the processing step also includes a second determination step of determining whether the maximum temperature change value ΔTmax is greater than the preset temperature T or whether the maximum voltage change value ΔVmax is greater than the preset voltage V. If so, a power-off step of powering off the battery cell is executed; if not, the power of the battery cell is reduced.

[0008] Furthermore, the power-off step includes utilizing a microgrid controller to control a battery management system to power off the battery unit.

[0009] Furthermore, the first execution step includes a third judgment step of judging whether the maximum temperature change value ΔTmax is greater than the preset temperature T, and if so, a power-off step of powering off the battery cell, and if not, executing a second execution step of making the battery cell operate normally or reducing the power of the battery cell according to the maximum voltage change value ΔVmax.

[0010] Furthermore, the second execution step includes a fourth judgment step of judging whether the maximum voltage change value ΔVmax is greater than the preset voltage V. If so, a power reduction step of reducing the power of the battery unit is executed; if not, a step of maintaining normal operation of the battery unit is executed.

[0011] Furthermore, the power reduction step includes the microgrid controller controlling the energy storage converter to reduce the power of the battery unit.

[0012] Furthermore, after the step of ensuring normal operation of the battery unit, the method for monitoring and handling cell faults in the energy storage system further includes a fifth judgment step of determining whether the difference between the current moment and the previous acquisition moment is greater than or equal to the acquisition period t; if so, executing the acquisition step; if not, executing a delay step of delaying for 1 second, and executing the fifth judgment step after the delay step.

[0013] Furthermore, the acquisition step includes: using the microgrid controller to collect the voltage Vi and temperature Ti of the battery cell i according to the collection period t; the voltage change value ΔVi=Vi 末 -Vi 初 , where Vi 末 is the voltage value collected at the end of the collection period t, Vi 初 is the voltage value collected at the initial collection time within the collection period t; the temperature change value ΔTi=Ti 末-Ti 初 , where Ti 末 is the temperature value collected at the end of the collection period t, Ti 初 is the temperature value collected at the initial collection time within the collection period t.

[0014] According to another aspect of the present invention, the present invention provides an energy storage system capable of running the above-mentioned energy storage system cell fault monitoring and processing method, the energy storage system comprising: multiple energy storage battery compartments, the energy storage battery compartments comprising an energy storage converter, a battery management system and multiple battery cells, wherein the energy storage converter performs AC / DC conversion with the power grid and controls the charge and discharge power of the battery cells, and the battery management system is used to collect voltage and temperature information of the multiple battery cells; a microgrid controller is controlled and connected to the energy storage converter and the battery management system of each energy storage battery compartment, the microgrid controller controls the battery cell to be powered off through the battery management system, and / or the microgrid controller controls the battery cell to reduce power through the energy storage converter.

[0015] The technical solution of the present invention, on the one hand, compared with the prior art that only uses the voltage of the battery cell as a judgment criterion, in this embodiment, not only abnormal voltage changes of the battery cell are identified, but also the battery cell temperature is added as an important basis for judging the battery cell status. The battery cell temperature is combined with the battery cell voltage, and the battery cell is judged based on the thermal runaway fault characteristics of the battery cell during a fault, which can improve the accuracy of fault judgment. On the other hand, in this embodiment, not only a fault monitoring method is proposed, but also specific fault handling means for the energy storage system after fault identification, such as a method for disconnecting the battery cell or reducing the power of the battery cell. In this way, the overall power outage can be avoided, thereby improving the stability and safety of the energy storage system operation, reducing the loss of the battery cell during a fault, and maximizing the operating efficiency of the energy storage system. Therefore, the battery cell fault monitoring and handling method of the energy storage system of this embodiment can determine the fault type (i.e., the severity of the fault) of the battery cell by combining the voltage and temperature, and take corresponding fault handling measures. In the face of fault behaviors with serious safety hazards, early identification and warning can be made, and the system can be adjusted to make the entire energy storage system more flexible. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0017] Figure 1 A schematic flow chart showing an embodiment of a method for monitoring and handling cell faults in an energy storage system according to the present invention;

[0018] Figure 2Another flow chart showing an embodiment of a method for monitoring and handling cell faults in an energy storage system according to the present invention; and

[0019] Figure 3 A schematic diagram of the system framework of an embodiment of the energy storage system of the present invention is shown. DETAILED DESCRIPTION

[0020] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0021] like Figure 3 As shown, an embodiment of the present invention provides an energy storage system. The energy storage system is capable of running the above-mentioned method for monitoring and handling cell faults of the energy storage system, and the energy storage system includes multiple energy storage battery compartments and a microgrid controller. Among them, the multiple energy storage battery compartments include an energy storage converter, a battery management system and multiple battery cells, wherein the energy storage converter performs AC / DC conversion with the power grid and controls the charge and discharge power of the battery cells, and the battery management system is used to collect voltage and temperature information of multiple battery cells; the microgrid controller is connected to the energy storage converter and the battery management system of each energy storage battery compartment, and the microgrid controller controls the battery cell to cut off power through the battery management system, and / or the microgrid controller controls the battery cell to reduce power through the energy storage converter.

[0022] Through the above-mentioned setting, compared with the prior art in which only the voltage of the battery cell is used as the judgment criterion, in this embodiment, not only the abnormal voltage change of the battery cell is identified, but the battery management system can also collect the change of the battery cell temperature to increase the battery cell temperature as the basis for judging the battery cell status, so as to improve the accuracy of fault judgment; on the other hand, in this embodiment, the microgrid controller controls the power off of the battery unit through the battery management system, and the microgrid controller controls the power reduction of the battery unit through the energy storage converter. In this way, the overall power off processing can be avoided, thereby improving the stability and safety of the energy storage system operation, reducing the loss of the battery unit during a fault, and maximizing the operating efficiency of the energy storage system.

[0023] Furthermore, the energy storage system of this embodiment deeply integrates the data processing and control functions of the microgrid controller. After identifying a fault, the microgrid controller can control the energy storage converter PCS and the battery management system BMS for system coordination, thereby improving the safety of the entire system.

[0024] Preferably, in an embodiment of the present invention, a circuit breaker is provided between the battery management system BMS and each battery cell. When an extreme abnormality occurs in a single cell in the battery cell, the circuit breaker can cut off the entire battery cell to protect the energy storage system.

[0025] Preferably, in an embodiment of the present invention, the battery management system adopts a microcontroller of the stm32-f4 model.

[0026] Preferably, in an embodiment of the present invention, the microgrid controller adopts an A53 processor.

[0027] Specifically, in an embodiment of the present invention, the battery management system is electrically connected to the multiple battery cells, and the energy storage converter is electrically connected to the multiple battery cells.

[0028] Preferably, in the embodiment of the present invention, the battery management system BMS and the energy storage converter PCS may also be electrically connected.

[0029] In one embodiment, a dry contact connection can also be used between the battery management system BMS and the energy storage converter PCS, so that when the battery management system BMS finds other serious faults in the battery cells, it can immediately notify the PCS to perform an overall power-off process for the energy storage system to avoid short circuits in the battery cells. It should be noted that in the embodiment of the present invention, the PCS has a power-off function.

[0030] It should be noted that, in the embodiment of the present invention, the energy storage battery compartment uses an energy storage container as a carrier, in which multiple battery units, a battery management system and an energy storage converter are installed.

[0031] like Figure 1 As shown, an embodiment of the present invention provides a method for monitoring and handling cell faults in an energy storage system. The energy storage system includes multiple battery cells, each of which includes multiple cells. The cell number is i, where i can be 1 to n, and n is an integer greater than 1. The method for monitoring and handling cell faults in the energy storage system includes: obtaining a voltage change value ΔVi and a temperature change value ΔTi of each cell i within a collection period t; comparing each voltage change value ΔVi, extracting a maximum voltage change value ΔVmax and a first cell number k corresponding to the maximum voltage change value ΔVmax; comparing each temperature change value ΔTi, extracting a maximum temperature change value ΔTmax and a second cell number K corresponding to the maximum temperature change value ΔTmax; judging whether the battery cell is faulty based on the maximum voltage change value ΔVmax, the maximum temperature change value ΔTmax, the first cell number k, and the second cell number K, and processing steps of making the battery cell operate normally, powering off the battery cell, or reducing the power of the battery cell.

[0032] In the above technical solution, on the one hand, compared with the prior art that only uses the voltage of the battery cell as a judgment criterion, this embodiment not only identifies abnormal voltage changes in the battery cell, but also adds the battery cell temperature as an important basis for judging the battery cell status. By combining the battery cell temperature with the battery cell voltage, and judging the battery cell based on the thermal runaway fault characteristics of the battery cell during a fault, the accuracy of fault judgment can be improved. On the other hand, this embodiment not only proposes a fault monitoring method, but also proposes specific fault handling methods for the energy storage system after fault identification, such as a method for disconnecting the battery cell or reducing the power of the battery cell. In this way, the overall power outage can be avoided, thereby improving the stability and safety of the energy storage system operation, reducing the loss of the battery cell during a fault, and maximizing the operating efficiency of the energy storage system. Therefore, the battery cell fault monitoring and handling method of the energy storage system of this embodiment can determine the fault type (i.e., the severity of the fault) of the battery cell by combining the voltage and temperature, and take corresponding fault handling measures. In the face of fault behaviors with serious safety hazards, early identification and warning can be made and the system can be adjusted, making the entire energy storage system more flexible.

[0033] It should be noted that, in the embodiment of the present invention, the first cell number k and the second cell number K both take values ​​from 1 to n, where n is an integer greater than 1; that is, k and K are any of the cell numbers.

[0034] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, the processing steps include a first judgment step of judging whether the first battery cell number k and the second battery cell number K are equal; if so, executing a judgment step of judging whether the battery cell is a faulty battery; if not, executing a first execution step of making the battery cell operate normally or power off the battery cell or reducing the power of the battery cell according to the maximum temperature change value ΔTmax and the maximum voltage change value ΔVmax.

[0035] In the above technical solution, it is determined whether the battery cell with the maximum voltage change and the maximum temperature change in the battery unit is the same battery cell. If so, it means that the battery cell has failed, that is, it can be determined that the battery unit where the battery cell is located has failed, so that subsequent operations can be performed on the battery unit; if not, the maximum pressure difference and the maximum temperature difference occur on different battery cells, then it can be further determined whether the battery unit with the maximum temperature difference and the maximum pressure difference has failed, and corresponding processing measures can be taken. In this way, the faults can be preliminarily classified, and subsequent response measures for different faults can be facilitated.

[0036] like Figure 2As shown, in an embodiment of the present invention, after the determination step, the processing step also includes a second determination step of determining whether the maximum temperature change value ΔTmax is greater than the preset temperature T or whether the maximum voltage change value ΔVmax is greater than the preset voltage V; if so, a power-off step of powering off the battery cell is executed; if not, the power of the battery cell is reduced.

[0037] If the battery cell with the maximum voltage change and the maximum temperature change in the battery unit is the same battery cell, the above settings can further classify the battery cell failures and take different countermeasures according to the different degrees of failure. For example, measures such as powering off the battery cell or reducing the power of the battery cell can be taken. Compared with the prior art of directly powering off the equipment, this can avoid the overall power outage, thereby improving the stability and safety of the energy storage system operation, reducing the loss of battery cells during failures, and maximizing the operating efficiency of the energy storage system.

[0038] It should be noted that, in an embodiment of the present invention, it is determined whether the maximum temperature change value ΔTmax is greater than the preset temperature T or whether the maximum voltage change value ΔVmax is greater than the preset voltage V. If so, the conditions that need to be met are ΔTmax>T and ΔVmax>V; or, ΔTmax≤T and ΔVmax>V; or, ΔTmax>T and ΔVmax≤V; if not, the conditions that need to be met are: ΔVmax≤V and ΔTmax≤T.

[0039] It should be noted that, in the embodiment of the present invention, reducing the power of the battery unit refers to reducing the charge and discharge power of the battery unit.

[0040] It should be noted that, in the embodiment of the present invention, the preset temperature T and the preset voltage V are both empirical values ​​obtained through multiple experiments.

[0041] like Figure 2 As shown, in the embodiment of the present invention, the power-off step includes utilizing a microgrid controller to control a battery management system to power off the battery unit.

[0042] If the faulty battery cell continues to charge, the maximum temperature change value and the maximum voltage change value will further increase, and the temperature increase will further intensify the chemical reaction inside the battery cell, further generate heat, and the internal resistance of the battery cell will further change, thereby further increasing the pressure difference. Therefore, through the above setting, the microgrid controller finds the battery management system BMS corresponding to the battery cell with the first battery cell number k or the second battery cell number K, and then the microgrid controller issues a cut-off isolation instruction to the battery management system BMS, which can cut off and isolate the faulty battery cell, thereby avoiding further pressure and temperature increases of the faulty battery.

[0043] Specifically, in an embodiment of the present invention, the voltage and temperature data collected by the battery management system BMS are fed back to the microgrid controller. The microgrid controller determines the battery cell corresponding to the faulty battery cell, and then finds the battery management system BMS corresponding to the battery cell. In this way, the specific fault location of the system can be accurately determined. The battery management system BMS then cuts off the power to the faulty battery cell or reduces the power of the battery cell, so as to make the most correct fault handling measures for the corresponding battery cell, thereby minimizing the loss.

[0044] like Figure 2 As shown, in an embodiment of the present invention, the first execution step includes a third judgment step of judging whether the maximum temperature change value ΔTmax is greater than a preset temperature T, and if so, a power-off step of powering off the battery unit, and if not, executing a second execution step of making the battery unit operate normally or reducing the power of the battery unit according to the maximum voltage change value ΔVmax.

[0045] Due to the rapid temperature rise, the internal diaphragm of the battery cell is usually damaged, which can easily cause thermal runaway of the battery. Therefore, through the above settings, when the maximum temperature change value ΔTmax of the battery cell exceeds the preset temperature T, the microgrid controller finds the battery management system BMS corresponding to the battery unit where the battery cell numbered second battery cell number K is located, and then the microgrid controller issues a cut-off isolation instruction to the battery management system BMS, which can cut off and isolate the faulty battery unit, so that the problem of thermal runaway caused by further temperature rise can be avoided.

[0046] like Figure 2 As shown, in an embodiment of the present invention, the second execution step includes a fourth judgment step of judging whether the maximum voltage change value ΔVmax is greater than the preset voltage V; if so, a power reduction step of reducing the power of the battery unit is executed; if not, a step of maintaining normal operation of the battery unit is executed.

[0047] When the maximum pressure difference change and the maximum temperature change occur on different battery cells, and the maximum temperature change value ΔTmax does not exceed the preset temperature T, and the maximum voltage change value ΔVmax exceeds the preset voltage V, at this time, the battery cell with the maximum pressure difference only has faults such as cold soldering, and there is no risk of serious safety hazards that may cause fire. Therefore, through the above settings, the battery unit corresponding to the battery cell can be depowered to reduce the pressure difference of the battery unit, thereby avoiding overall power outage processing, avoiding affecting the normal operation of the system, and troubleshooting after the system is shut down, thereby reducing the loss of the battery unit during the fault and maximizing the operating efficiency of the energy storage system.

[0048] When the maximum voltage difference change and the maximum temperature change occur on different battery cells, and the maximum temperature change value ΔTmax does not exceed the preset temperature T, and the maximum voltage change value ΔVmax does not exceed the preset voltage V, it means that the battery cell has not failed, and the normal operation of the battery unit can be guaranteed.

[0049] like Figure 2 As shown, in the embodiment of the present invention, the power reduction step includes the microgrid controller controlling the energy storage converter to reduce the power of the battery unit.

[0050] In the above technical solution, the microgrid controller finds the energy storage converter PCS corresponding to the battery unit where the battery cell numbered k is located, and then the microgrid controller issues a power reduction instruction to the energy storage converter PCS, thereby reducing the charging and discharging power of the battery unit. This can avoid overall power outage processing, thereby improving the stability and safety of the energy storage system operation, reducing the loss of the battery unit in the event of a fault, and maximizing the operating efficiency of the energy storage system.

[0051] Specifically, in the embodiment of the present invention, the acquisition step includes: using the microgrid controller to collect the voltage Vi and temperature Ti of the battery cell i according to the collection period t; the voltage change value ΔVi=Vi 末 -Vi 初 , where Vi 末 is the voltage value collected at the end of the collection period t, Vi 初 is the voltage value collected at the initial collection time within the collection period t; the temperature change value ΔTi=Ti 末 -Ti 初 , where Ti 末 is the temperature value collected at the end of the collection period t, Ti 初 is the temperature value collected at the initial collection time within the collection period t. In this way, the voltage change value and temperature change value of each battery cell within the collection period t can be obtained.

[0052] Specifically, in the embodiment of the present invention, before the collection step, the microgrid controller MC is started, and a collection period of the battery management system BMS data by the microgrid controller MC is set to 3S.

[0053] Specifically, in an embodiment of the present invention, during the collection process, data can be stored in the storage unit of the microgrid controller MC. After every collection cycle of 3S, the cell voltage and cell temperature in the storage unit are updated, the previous initial cell temperature and initial cell voltage are replaced with the terminal cell voltage and terminal cell temperature, and the latest cell voltage and cell temperature data are collected from the battery management system BMS as the terminal cell voltage and terminal cell temperature. This can greatly reduce the proportion of data in the memory of the microgrid controller MC and improve computing efficiency.

[0054] like Figure 2 As shown, in an embodiment of the present invention, after the step of ensuring normal operation of the battery unit, the method for monitoring and handling cell faults in the energy storage system further includes a fifth judgment step of judging whether the difference between the current moment and the previous acquisition moment is greater than or equal to the acquisition period t; if so, the acquisition step is executed; if not, the delay step of delaying for a preset time is executed, and the fifth judgment step is executed after the delay step.

[0055] Through the above settings, the energy storage system can be diagnosed cyclically by setting a fixed period t, so as to timely discover hidden faults of the energy storage system and avoid the problem of the entire system failing due to a single cell failure.

[0056] Preferably, in an embodiment of the present invention, the preset time is 1 second and the acquisition period t is 3 seconds.

[0057] It should be noted that the cell fault monitoring and processing method of the energy storage system in the embodiment of the present invention can accurately identify the fault type of the battery cell during the charging and discharging process, accurately determine the specific fault location of the system, and thus make the most accurate judgment through the microgrid controller. The microgrid controller can then find the energy storage converter and battery management system corresponding to the faulty battery cell, and take corresponding fault handling measures to maximize the operating efficiency of the battery system.

[0058] The cell fault monitoring and processing method of the above energy storage system has all the advantages of the above energy storage system and will not be described in detail here.

[0059] From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects: on the one hand, compared with the prior art which only uses the voltage of the battery cell as the judgment standard, this embodiment not only identifies the abnormal voltage change of the battery cell, but also adds the battery cell temperature as an important basis for judging the battery cell status, combines the battery cell temperature with the battery cell voltage, and judges the battery cell based on the thermal runaway fault characteristics of the battery cell when it fails, which can improve the accuracy of fault judgment; on the other hand, this embodiment not only proposes a fault monitoring method, but also proposes specific means for the energy storage system to handle the fault after the fault is identified, such as , a processing method for cutting off the power of the battery unit or reducing the power of the battery unit. In this way, the overall power-off processing can be avoided, thereby improving the stability and safety of the energy storage system operation, reducing the loss of the battery unit in the event of a fault, and maximizing the operating efficiency of the energy storage system; therefore, the battery cell fault monitoring and processing method of the energy storage system of this embodiment can determine the fault type of the battery unit (i.e., the severity of the fault) by combining voltage and temperature, and make corresponding fault processing measures. In the face of fault behaviors with serious safety hazards, early identification and warning can be made and the system can be adjusted to make the entire energy storage system more flexible.

[0060] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for monitoring and handling battery cell failures in an energy storage system, characterized in that: The energy storage system includes a plurality of battery units, each of which includes a plurality of battery cells, each of which is numbered i, where i can be 1 to n, and n is an integer greater than 1. The battery cell fault monitoring and processing method of the energy storage system includes: The step of obtaining the voltage change value ΔVi and the temperature change value ΔTi of each battery cell i within the acquisition period t; Comparing the voltage change values ​​ΔVi, extracting the maximum voltage change value ΔVmax and the first cell number k corresponding to the maximum voltage change value ΔVmax; Comparing the temperature change values ​​ΔTi, extracting the maximum temperature change value ΔTmax and the second battery cell number K corresponding to the maximum temperature change value ΔTmax; a processing step of determining whether the battery cell is faulty according to the maximum voltage change value ΔVmax, the maximum temperature change value ΔTmax, the first battery cell number k, and the second battery cell number K, and enabling the battery cell to operate normally, or disconnecting the battery cell, or reducing the power of the battery cell; The processing steps include a first judgment step of determining whether the first battery cell number k and the second battery cell number K are equal. If so, a judgment step of determining whether the battery cell is a faulty battery is executed. If not, a first execution step of making the battery cell operate normally or power off the battery cell or reducing the power of the battery cell is executed based on the maximum temperature change value ΔTmax and the maximum voltage change value ΔVmax.

2. The method for monitoring and handling cell failures of an energy storage system according to claim 1, wherein: After the determination step, the processing step further includes a second determination step of determining whether the maximum temperature change value ΔTmax is greater than a preset temperature T or whether the maximum voltage change value ΔVmax is greater than a preset voltage V. If so, a power-off step of powering off the battery cell is executed; if not, the power of the battery cell is reduced.

3. The method for monitoring and handling battery cell failures of an energy storage system according to claim 2, wherein: The power-off step includes utilizing a microgrid controller to control a battery management system to power off the battery unit.

4. The method for monitoring and handling cell failures of an energy storage system according to claim 1, wherein: The first execution step includes a third judgment step of judging whether the maximum temperature change value ΔTmax is greater than a preset temperature T, and if so, a power-off step of powering off the battery unit, and if not, executing a second execution step of making the battery unit operate normally or reducing the power of the battery unit according to the maximum voltage change value ΔVmax.

5. The method for monitoring and handling cell failures of an energy storage system according to claim 4, wherein: The second execution step includes a fourth judgment step of judging whether the maximum voltage change value ΔVmax is greater than a preset voltage V. If so, a power reduction step of reducing the power of the battery unit is executed; if not, a step of maintaining normal operation of the battery unit is executed.

6. The method for monitoring and handling cell failures of an energy storage system according to claim 5, wherein: The power reduction step includes a microgrid controller controlling an energy storage converter to reduce the power of the battery unit.

7. The method for monitoring and handling cell failures of an energy storage system according to claim 5, wherein: After the step of ensuring the normal operation of the battery unit, the method for monitoring and handling cell faults in the energy storage system further includes a fifth judgment step of determining whether the difference between the current moment and the previous acquisition moment is greater than or equal to the acquisition period t; if so, executing the acquisition step; if not, executing a delay step for a preset time, and executing the fifth judgment step after the delay step.

8. The method for monitoring and handling cell failures of an energy storage system according to any one of claims 1 to 7, characterized in that: The obtaining step comprises: The step of collecting the voltage Vi and temperature Ti of the battery cell i using a microgrid controller according to a collection period t; Voltage change ΔVi=Vi 末 -Vi 初 , where Vi 末 is the voltage value collected at the end of the collection period t, Vi 初 is the voltage value collected at the initial collection time within the collection period t; Temperature change ΔTi=Ti 末 -Ti 初 , where Ti 末 is the temperature value collected at the end of the collection period t, Ti 初 is the temperature value collected at the initial collection time within the collection period t.

9. An energy storage system, characterized in that: A method for monitoring and handling cell faults of an energy storage system capable of operating any one of claims 1 to 8, the energy storage system comprising: Multiple energy storage battery compartments, each comprising an energy storage converter, a battery management system, and multiple battery cells. The energy storage converter performs AC / DC conversion with the power grid and controls the charge and discharge power of the battery cells. The battery management system is configured to collect voltage and temperature information of the multiple battery cells. The microgrid controller is connected to the energy storage converter and the battery management system of each energy storage battery compartment. The microgrid controller controls the battery unit to be powered off through the battery management system, and / or controls the battery unit to be powered down through the energy storage converter.

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