Energy storage system and method of operating the same

Abstract

An energy storage system according to one embodiment disclosed herein includes: an inverter electrically connected to a power grid; a converter configured to receive a communication signal and an enable signal related to an operating state of the inverter from the inverter, and connected to the inverter through a power transmission line; and a controller configured to determine a power-off state of the grid or a state of power supply from the inverter to the converter based on the communication signal and the enable signal.

Description

TECHNICAL FIELD

[0001] Cross Reference to Related Applications

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0112144, filed on August 25, 2023, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0004] Embodiments disclosed herein relate to a storage energy system for determining a power outage state of a power grid and a method of operating the same. BACKGROUND

[0005] A storage energy system (ESS) is a device that can achieve efficient use of power by temporarily storing power generated from a power plant or the like during a period of less power demand from a power grid and supplying the stored power to the power grid during a period of more power demand. Recently, interest in a residential ESS that can store power generated using solar energy or the like has increased.

[0006] The ESS mainly includes an inverter connected to the power grid, a battery for storing power supplied by the power grid, a converter for performing DC-DC conversion, and the like.

[0007] The ESS performs a restoration operation for supplying power or the like, prepares for an unexpected power outage or a failure. In the case of a power outage in the power grid or a problem with the inverter, power stored in the battery should be supplied, but there is a problem in that the user needs to operate the ESS to perform a restoration operation or the like since the converter is difficult to recognize the power outage or the problem with the inverter. SUMMARY

[0008] TECHNICAL PROBLEM

[0009] Embodiments disclosed herein relate to providing a storage energy system for determining a power outage state of a power grid and a method of operating the same.

[0010] The objects of the embodiments disclosed herein are not limited to the above-mentioned objects, and other objects not described will be clearly understood by those skilled in the art from the following description.

[0011] TECHNICAL SOLUTION

[0012] A storage energy system according to one embodiment disclosed herein can include an inverter electrically connected to a power grid, a converter configured to receive a communication signal and an enable signal related to an operating state of the inverter from the inverter and connected to the inverter through a power transmission line, and a controller configured to determine a power outage state of the power grid based on the communication signal and the enable signal.

[0013] According to one embodiment, when no communication signal is received within a preset threshold time, the controller can check whether the inverter is in an operating state based on an enable signal received through a second communication line connected between the inverter and the converter.

[0014] According to one embodiment, when the enable signal is in a logic high state indicating that the inverter is in an operating state, the controller can determine that there is a communication failure state, which is a state in which no communication signal is received between the inverter and the converter.

[0015] According to one embodiment, the energy storage system may further include a battery module connected to a converter to store power supplied from the inverter, wherein when an enable signal is in a logic low state indicating that the inverter is in a non-operating state, the controller can control the battery module and the converter to supply the power stored in the battery module to the inverter.

[0016] According to one embodiment, when the voltage of the battery module is sufficient to power on the inverter, the controller can supply power to the inverter.

[0017] According to one embodiment, the controller can check whether the inverter is in an operational state based on an enable signal received after power is supplied to the inverter.

[0018] According to one embodiment, when the enable signal received after power supply is in a logic low state indicating that the inverter is in a non-operating state, the controller can determine that a fault has occurred in the power supply equipment connected to the inverter to drive the inverter.

[0019] According to one embodiment, when the enable signal received after power supply is in a logic high state indicating that the inverter is in an operating state, the controller can control the converter to send a request signal for requesting a communication signal from the inverter to the inverter.

[0020] According to one embodiment, a communication signal can be received through a first communication line connected between the inverter and the converter, and if no communication signal provided by the inverter in response to a request signal is received within a preset reference time, the controller can determine that a fault has occurred in the first communication line.

[0021] According to one embodiment, when a communication signal provided by the inverter in response to a request signal is received within a threshold time, the controller can determine that a power outage has occurred in the power grid.

[0022] A method for operating an energy storage system according to an embodiment disclosed herein may include: determining a communication state between an inverter and a converter, determining an operating state of the inverter based on the communication state, supplying power to the inverter, and determining a power outage state of the power grid electrically connected to the inverter based on communication signals received between the inverter and the converter.

[0023] According to one embodiment, determining the communication status between the inverter and the converter may include: determining whether a communication signal received through a first communication line connected between the inverter and the converter is received within a preset threshold time.

[0024] According to one embodiment, determining the operating state of the inverter may include: receiving an enable signal related to the operating state of the inverter via a second communication line connected between the inverter and the converter, and determining that a communication failure has occurred between the inverter and the converter when the enable signal is in a logic high state.

[0025] According to one embodiment, supplying power to the inverter may include: controlling a battery module and a converter to supply power stored in the battery module connected to the converter to the inverter; and determining that a fault has occurred in the power supply equipment connected to the inverter to supply power to the inverter when an enable signal received through a second communication line is in a logic low state, and sending a request signal for requesting a communication signal from the inverter when the enable signal is in a logic high state.

[0026] According to one embodiment, when the voltage of the battery module is sufficient to power on the inverter, power can be supplied to the inverter.

[0027] According to one embodiment, determining the power outage state of the power grid may include: determining that a fault has occurred in the first communication line when no communication signal provided by the inverter in response to the request signal is received within a preset reference time; and determining that a power outage has occurred in the power grid when a communication signal provided by the inverter in response to the request signal is received within the preset reference time.

[0028] Beneficial effects

[0029] According to an embodiment of the energy storage system and method of operating the energy storage system disclosed herein, it is possible to determine the power outage state of the power grid and supply power to the inverter. Attached Figure Description

[0030] Figure 1 This is a view used to describe an energy storage system and nearby components according to an embodiment disclosed herein.

[0031] Figure 2 This is a view used to describe an energy storage system according to an embodiment disclosed herein.

[0032] Figure 3 This is a view used to describe the operation of an energy storage system and controller over time according to an embodiment disclosed herein.

[0033] Figure 4 This is a view used to schematically illustrate the operation of an energy storage system according to an embodiment disclosed herein.

[0034] Figure 5 This is a flowchart specifically describing the operation of an energy storage system according to an embodiment disclosed herein. Detailed Implementation

[0035] In the following, embodiments disclosed herein will be described in detail with reference to exemplary accompanying drawings. When adding reference numerals to components in each drawing, care should be taken to ensure that identical components have the same reference numerals whenever possible, even if they are shown in different drawings. Furthermore, in describing embodiments disclosed herein, detailed descriptions will be omitted when it is determined that a detailed description of a related known configuration or function obscures the understanding of the embodiments disclosed herein.

[0036] Terms such as first, second, A, B, (a), and (b) may be used to describe components of the embodiments disclosed herein. These terms are used only to distinguish one component from another, and the nature, order, sequence, etc., of the corresponding components are not limited by these terms. Furthermore, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments disclosed herein pertain. Terms defined in common dictionaries should be interpreted as meanings matching the meanings of terms in the context of the relevant art and should not be interpreted as ideal or overly formal meanings unless expressly defined in this application.

[0037] Figure 1 This is a view used to describe an energy storage system and nearby components according to an embodiment disclosed herein.

[0038] refer to Figure 1 The energy storage system 1000 can be electrically connected to the power generation system 10, the power grid 20 and the load 30.

[0039] The power generation system 10 can be a system for generating electricity using an energy source. The electricity generated by the power generation system 10 can be supplied to the energy storage system 1000. The power generation system 10 may include, but is not limited to, solar power generation systems, wind power generation systems, tidal power generation systems, etc. For example, the power generation system 10 may include a system for generating electricity using renewable energy sources such as solar thermal, solar, or geothermal energy.

[0040] The power grid 20 can be a network connecting power producers and power consumers, and it includes concepts such as power plants for generating electricity, substations for increasing or decreasing voltage for transmission / distribution, transmission lines for transmitting electricity, and distribution lines for transmitting electricity to power consumers. When the power grid 20 is operating normally, it can supply electricity to the energy storage system 1000. Furthermore, the power grid 20 can receive electricity from the energy storage system 1000. When the power grid 20 is not operating normally, the power supply from the power grid 20 to the energy storage system 1000 can be stopped. Additionally, the power supply from the energy storage system 1000 to the power grid 20 can also be stopped.

[0041] According to one embodiment, abnormal operation of the power grid 20 may include a power outage in the power grid 20.

[0042] Load 30 may consume electricity generated by power generation system 10, electricity stored in energy storage system 1000, or electricity supplied from grid 20. For example, load 30 may refer to any consumer that consumes electricity, such as a factory or household.

[0043] The energy storage system 1000 may include a power conversion unit 1100 and a battery system 1200.

[0044] The power conversion unit 1100 can appropriately convert power when the energy storage system 1000 supplies power to the grid 20 or the load 30, or when the generation system 10 supplies power to the energy storage system 1000. The power conversion unit 1100 may include a power conversion system (PCS). The power conversion unit 1100 can convert AC power to DC power or vice versa.

[0045] Battery system 1200 can store electricity supplied by power generation system 10 or grid 20. When energy storage system 1000 supplies electricity to grid 20 or load 30, energy storage system 1000 can provide the electricity stored in battery system 1200. Battery system 1200 may include battery racks, battery modules, battery packs, etc. for storing electricity.

[0046] Figure 2 This is a view used to describe an energy storage system according to an embodiment disclosed herein.

[0047] refer to Figure 2 The power conversion unit 1100 may include an inverter unit 1110, and the battery system 1200 may include a converter unit 1210 and a battery module 1220.

[0048] Battery system 1100 can be converted from Figure 1 The power is supplied by the power generation system 10 or the power grid 20 shown. The power conversion unit 1100 may include an inverter unit 1110.

[0049] The inverter 1111 included in the inverter unit 1110 can convert AC power supplied by the power generation system or the power grid 20 into DC power. Furthermore, the inverter 1111 can convert DC power supplied by the battery system 1200 into AC power. The inverter 1111 can be a bidirectional inverter. The power supply device 1112 can supply power to the inverter 1111 to drive it.

[0050] Battery system 1200 can store data from... Figure 1 The power is provided by the power generation system 10 or the power grid 20 shown. The battery system 1200 may include a converter unit 1210 and a battery module 1220.

[0051] Converter unit 1210 may include DC-DC converter 1211 and controller 1212. DC-DC converter 1211 may convert DC power received from inverter unit 1110 into DC power to be stored in battery module 1220, or convert the DC level of DC power stored in battery module 1220 before transmitting DC power to grid 20 or load. DC-DC converter 1211 may be implemented as a linear regulator, etc.

[0052] Inverter unit 1110 and converter unit 1210 can be connected based on at least one communication line and power transmission line.

[0053] According to one embodiment, the inverter unit 1110 and the converter unit 1210 can be connected via a first communication line, a second communication line, and a power transmission line.

[0054] The first communication line can be a bidirectional communication line connecting the inverter unit 1110 to the converter unit 1210. The inverter unit 1110 can send communication signals to the converter unit 1210 through the first communication line, and the converter unit 1210 can receive communication signals provided by the inverter unit 1110 through the first communication line.

[0055] According to one embodiment, the first communication line may be a communication line capable of checking the communication status between the inverter unit 1110 and the converter unit 1210. When no communication signal is sent or received between the inverter unit 1110 and the converter unit 1210 through the first communication line within a preset threshold time, a communication loss (LOC) state may exist, which is a state of poor communication between the inverter unit 1110 and the converter unit 1210.

[0056] According to one embodiment, the communication signals may include multiple signals exchanged between the inverter unit 1110 and the converter unit 1210. For example, the communication signals may include a request signal requesting the converter unit 1210 to respond to the inverter unit 1110. Furthermore, the communication signals may include a heartbeat signal provided by the inverter unit 1110 to the converter unit 1210 in response to the request signal. The heartbeat signal is a signal that occurs periodically in response to the request signal and may be a signal related to the communication status between the inverter unit 1110 and the converter unit 1210.

[0057] According to one embodiment, the inverter unit 1110 and the converter unit 1210 can be connected via a first communication line according to the RS-485 communication standard, but are not limited thereto, and can be connected via various communication standards, communication specifications or communication protocols.

[0058] The second communication line can be a unidirectional communication line connecting the inverter unit 1110 to the converter unit 1210. That is, the object sending the signal and the object receiving the signal through the second communication line can remain unchanged.

[0059] According to one embodiment, inverter unit 1110 can transmit signals via a second communication line, and converter unit 1210 can receive signals transmitted by inverter unit 1110 via the second communication line. Inverter unit 1110 can send an enable signal to converter unit 1210 via the second communication line. The enable signal can be a signal related to the operation of inverter unit 1110, and can be a signal represented as 1 bit indicating whether inverter unit 1110 is operating normally.

[0060] According to one embodiment, when the enable signal is in a logic high state, it can indicate that the inverter unit 1110 is in a normal operating state. Conversely, when the enable signal is in a logic low state, it can indicate that the inverter unit 1110 is in an abnormal operating state.

[0061] According to one embodiment, a logic high state can be a state in which the bit value is "1" and a logic low state can be a state in which the bit value is "0". However, this document is not limited to this and, depending on the design, a logic high state can be a state in which the bit value is "0" and a logic low state can be a state in which the bit value is "1".

[0062] According to one embodiment, the abnormal operation of inverter unit 1110 may include the state in which inverter unit 1110 does not supply power to converter unit 1210 through power transmission lines.

[0063] The power transmission line can be a line that transmits power between the inverter unit 1110 and the converter unit 1210. For example, the inverter unit 1110 can appropriately convert the power supplied by the grid 20 and transmit the converted power to the converter unit 1210 via the power transmission line. The power transmission line may include a switch (not shown).

[0064] According to one embodiment, a power transmission line may be connected to a power supply device 1112 included in the inverter unit 1110. The power supply device 1112 may control the power supply of the inverter 1111 based on the power supplied by the converter unit 1210. Furthermore, the power supply device 1112 may fully manage the power supplied by the inverter 1111. Figure 1 The power supplied by the power grid 20 or power generation system 10 shown.

[0065] According to one embodiment, when the power grid 20 is normally supplying... Figure 1 When the energy storage system 1000 shown in the figure supplies power, the switch (not shown) of the power transmission line can be disconnected.

[0066] According to one embodiment, when a power outage occurs in the power grid 20 and the power stored in the battery module 1220 should be supplied to the power grid 20, a switch of the power transmission line can be connected.

[0067] The controller 1212 can control the overall operation of the converter unit 1210.

[0068] The converter unit 1210 can be electrically connected to the battery module 1220, and the controller 1212 can control the converter unit 1210 to store the power received by the converter unit 1210 in the battery module 1220.

[0069] When a power outage occurs in the power grid 20, the controller 1212 can control the converter unit 1210 to supply power from the battery module 1220 to the power grid 20. Furthermore, when the inverter unit 1110 malfunctions, the controller 1212 can control the converter unit 1210 to supply power to the inverter unit 1110. The following will... Figure 3 The description describes the operation of controller 1212.

[0070] Figure 3 This is a view used to describe the operation of an energy storage system and controller over time according to an embodiment disclosed herein.

[0071] refer to Figure 3 The diagram illustrates the operation of components 1111, 1211, and 1220 included in the energy storage system over time.

[0072] Inverter 1111 can convert AC power supplied by grid 20 into DC power. Inverter 1111 can convert AC power into DC power and transmit the DC power to DC-DC converter 1211.

[0073] DC-DC converter 1211 converts the received DC power level into a DC power level that can be stored in battery module 1220. The DC power converted by DC-DC converter 1211 can be transferred to battery module 1220. Battery module 1220 can store the DC power transferred by DC-DC converter 1211.

[0074] Over time, a LOC (Lost in Communication) state may occur, which is a state of poor communication between the inverter 1111 and the DC-DC converter 1211. According to one embodiment, the LOC state may be a state in which no communication signal is sent or received through the first communication line for a preset threshold time.

[0075] When no communication signal is sent or received through the first communication line within a threshold time, the controller 1212 can check the enable signal received from the inverter 1111.

[0076] According to one embodiment, the enable signal may be a signal related to the operation of the inverter 1111. For example, when the enable signal is in a logic high state, the inverter 1111 may be in a normal operating state, and when the enable signal is in a logic low state, the inverter 1111 may be in an abnormal operating state.

[0077] According to one embodiment, when the enable signal is in a logic high state, power can be supplied from the inverter to the converter. When the enable signal is in a logic low state, power can not be supplied from the inverter to the converter.

[0078] When the enable signal is in a logic low state (①), the controller 1212 can determine that the inverter 1111 is in an abnormal operating state. The controller 1212 can control the battery module 1220 and the DC-DC converter 1211 to supply the inverter 1111 with the power stored in the battery module 1220. The power stored in the battery module 1220 can be transmitted to the inverter 1111 through the DC-DC converter 1211 and the power transmission line.

[0079] According to one embodiment, when the enable signal is in a logic low state (①), the controller 1212 can check whether the voltage of the battery module 1220 is sufficient to turn on the inverter 1111. When the voltage of the battery module 1220 is sufficient to turn on the inverter 1111, the controller 1212 can control the battery module 1220 and the DC-DC converter 1211 to supply power to the inverter 1111.

[0080] When the enable signal is in a logic high state (②), the controller 1212 can determine that the inverter 1111 is in a normal operating state. Although the inverter 1111 is in a normal operating state, since no communication signal is sent or received through the first communication line within the threshold time, the controller 1212 can determine that a communication failure has occurred between the inverter 1111 and the DC-DC converter 1211.

[0081] According to one embodiment, the communication failure status may include the LOC status.

[0082] When the enable signal returns to a logic low state (①), the controller 1212 can check the operating state of the inverter 1111 based on the enable signal received after power is supplied to the inverter 1111.

[0083] When the enable signal is in a logic low state (③), the controller 1212 can determine that a problem has occurred in the power supply equipment connected to the inverter 1111 to drive the inverter 1111. This is because sufficient power is being transmitted from the battery module 1220 to power on the inverter 1111, but the inverter 1111 is in an abnormal operating state. The power supply equipment could be... Figure 2 The power supply equipment 1112 shown is shown.

[0084] When the enable signal is in a logic high state (④), the controller 1212 can control the DC-DC converter 1211 to send a request signal to the inverter 1111 through the first communication line.

[0085] According to one embodiment, the request signal may be a signal requesting the DC-DC converter 1211 to respond to the inverter 1111.

[0086] The controller 1212 can control the DC-DC converter 1211 to send a request signal to the inverter 1111 and check whether a communication signal is received within a preset reference time. According to one embodiment, the communication signal may be a heartbeat signal.

[0087] According to one embodiment, the reference time may be 10 seconds, but is not limited to this, and the reference time may be changed in various ways depending on the design.

[0088] When a communication signal (⑤) is received within the reference time, the controller 1212 can determine that a power outage has occurred in the power grid 20. When no communication signal (⑥) is received within the reference time, the controller 1212 can determine that a fault has occurred in the first communication line.

[0089] The controller 1212 can detect power outages that have occurred in the power grid 20 through the aforementioned process. Furthermore, the controller 1212 can perform various diagnostic procedures during the detection of power outages in the power grid 20. That is, when the inverter 1111 is in an inactive state using an enable signal, the controller 1212 can supply power to the inverter 1111 and determine whether a fault has occurred in the inverter 1111 based on subsequent enable signals. Additionally, the controller 1212 can control the DC-DC converter 1211 to send request signals and determine whether a communication line fault has occurred based on the received heartbeat signal. Therefore, the controller 1212 can not only directly detect power outages in the power grid 20, but also determine whether faults have occurred in the inverter 1111, converter 1211, etc., during the detection of power outages in the power grid 20, thereby improving the reliability of detecting power outages occurring in the power grid 20.

[0090] Figure 4 and Figure 5 This is a flowchart describing the operation of an energy storage device according to an embodiment disclosed herein.

[0091] Figure 4 This is a view used to schematically illustrate the operation of an energy storage system according to an embodiment disclosed herein, and Figure 5 This is a flowchart specifically describing the operation of an energy storage system according to an embodiment disclosed herein.

[0092] refer to Figure 4 In operation S401, the energy storage system can determine the communication status between the inverter and the converter.

[0093] According to one embodiment, operation S401 may include Figure 5 Operations S501 to S505 are shown below. The energy storage system can check the communication signal received through the first communication line connected between the inverter and the converter (S501) and determine whether there is a communication signal received through the first communication line within a threshold time (S503). When there is a communication signal exchanged between the inverter and the converter through the first communication line (yes), the energy storage system can determine that the communication status between the inverter and the converter is normal (S505). When there is no communication signal exchanged between the inverter and the converter through the first communication line (no), operation S507 can continue.

[0094] Return to reference Figure 4 The energy storage system can check the operating status of the inverter (S403).

[0095] According to one embodiment, operation S403 may include Figure 5Operations S507 to S511 are shown below. The energy storage system can check the enable signal received through the second communication line connected between the inverter and the converter (S507) and check whether the enable signal is in a logic low state (S509). When the enable signal is in a logic high state (No), the energy storage system can determine that a communication failure has occurred between the inverter and the converter (S511). When the enable signal is in a logic low state (Yes), operation S513 can continue.

[0096] According to one embodiment, a communication failure may include a LOC state.

[0097] Return to reference Figure 4 The energy storage system can supply power to the inverter (S405).

[0098] According to one embodiment, operation S405 may include Figure 5 Operations S513 to S521 are shown below. The energy storage system can transfer power stored in the battery module electrically connected to the converter to the inverter (S513). After transferring power to the inverter, the energy storage system can check the enable signal received through the second communication line (S517). When the enable signal is in a logic low state (yes), the energy storage system can determine that a problem has occurred in the power supply equipment connected to the inverter (S519). When the enable signal is in a logic high state (no), the energy storage system can send a request signal to the inverter to request a communication signal (S521).

[0099] According to one embodiment, when the voltage of the battery module is sufficient to power on the inverter, the power stored in the battery module can be transferred to the inverter.

[0100] Return to reference Figure 4 The energy storage system can determine whether a power outage has occurred in the grid based on the communication signals received between the inverter and the converter (S407).

[0101] According to one embodiment, operation S407 may include Figure 5 Operations S523 to S527 are shown below. The energy storage system can determine whether it has received a communication signal provided by the inverter in response to a request signal within a reference time (S523). If no communication signal is received within the reference time (No), the energy storage system can determine that a fault has occurred in the first communication line between the inverter and the converter (S525). If a communication signal is received within the reference time (Yes), the energy storage system can determine that a power outage has occurred in the power grid (S527).

[0102] According to one embodiment, the communication signal sent by the inverter in response to a request signal may be a heartbeat signal.

[0103] All components constituting the embodiments have been described above as operating coupled as one or by means of coupling, but are not necessarily limited to these embodiments, and for the purposes of this study, one or more of all components may operate by selective coupling. Furthermore, unless otherwise stated, the foregoing terms such as “comprising,” “constituting,” or “having” mean that the corresponding component may be inherent and should therefore be interpreted as further including rather than excluding another component.

[0104] The above description is merely an exemplary description of the technical spirit disclosed herein, and those skilled in the art to which the embodiments disclosed herein pertain will be able to modify and change the embodiments in various ways without departing from the basic characteristics of the embodiments disclosed herein.

[0105] Therefore, the embodiments disclosed herein are not intended to limit the technical spirit disclosed herein, but are used to describe it, and the scope of the technical spirit disclosed herein is not limited by these embodiments. The scope of the technical spirit disclosed herein should be interpreted by the appended claims, and all technical spirit within the equivalent scope should be interpreted as being included within the scope of this document.

[0106] [Description of reference numerals in the attached figures]

[0107] 10: Power generation system 20: Power grid

[0108] 30: Load 1000: Energy Storage System

[0109] 1100: Power conversion unit; 1110: Inverter unit

[0110] 1111: Inverter; 1112: Power supply equipment

[0111] 1200: Battery system; 1210: Converter unit

[0112] 1211: DC-DC converter; 1212: Controller

[0113] 1220: Battery Module

Claims

1. An energy storage system, comprising: Inverter, the inverter being electrically connected to the power grid; A converter configured to receive communication signals and enable signals related to the operating state of the inverter from the inverter, and connected to the inverter via a power transmission line; as well as A controller configured to determine the power outage state of the power grid based on the communication signal and the enable signal.

2. The energy storage system according to claim 1, wherein, When the communication signal is not received within a preset threshold time, the controller checks whether the inverter is in the operating state based on the enable signal received through the second communication line connected between the inverter and the converter.

3. The energy storage system according to claim 2, wherein, When the enable signal is in a logic high state indicating that the inverter is in the operating state, the controller determines that there is a communication failure state, which is a state in which the communication signal is not received between the inverter and the converter.

4. The energy storage system of claim 2 further includes a battery module connected to the converter to store electricity supplied from the inverter. in, When the enable signal is in a logic low state indicating that the inverter is in a non-operating state, the controller controls the battery module and the converter to supply the power stored in the battery module to the inverter.

5. The energy storage system according to claim 4, wherein, When the voltage of the battery module is sufficient to power the inverter, the controller supplies power to the inverter.

6. The energy storage system according to claim 4, wherein, The controller checks whether the inverter is in an operational state based on an enable signal received after power is supplied to the inverter.

7. The energy storage system according to claim 6, wherein, When the enable signal received after power supply is in the logic low state, indicating that the inverter is in the non-operating state, the controller determines that a fault has occurred in the power supply equipment connected to the inverter to drive the inverter.

8. The energy storage system according to claim 6, wherein, When the enable signal received after power supply is in a logic high state indicating that the inverter is in an operating state, the controller controls the converter to send a request signal for requesting a communication signal to the inverter.

9. The energy storage system according to claim 8, wherein, The communication signal is received through a first communication line connected between the inverter and the converter, and If no communication signal is received from the inverter in response to the request signal within a preset reference time, the controller determines that a fault has occurred in the first communication line.

10. The energy storage system according to claim 8, wherein, When the controller receives a communication signal provided by the inverter in response to the request signal within the threshold time, it determines that a power outage has occurred in the power grid.

11. A method for operating an energy storage system, comprising: Determine the communication status between the inverter and the converter; The operating state of the inverter is determined based on the communication status. Power is supplied to the inverter; as well as The power outage status of the power grid connected to the inverter is determined based on the communication signals received between the inverter and the converter.

12. The method according to claim 11, wherein, Determining the communication state between the inverter and the converter includes determining whether the communication signal received through the first communication line connected between the inverter and the converter is received within a preset threshold time period.

13. The method according to claim 12, wherein, Determining the operating state of the inverter includes: Receive an enable signal related to the operating state of the inverter via a second communication line connected between the inverter and the converter; and When the enable signal is in a logic high state, it is determined that a communication failure has occurred between the inverter and the converter.

14. The method according to claim 13, wherein, Supplying power to the inverter includes: Control the battery module and the converter to supply the inverter with electricity stored in the battery module connected to the converter; and When the enable signal received through the second communication line is in a logic low state, it is determined that a fault has occurred in the power supply equipment connected to the inverter to supply power to the inverter, and when the enable signal is in a logic high state, a request signal for requesting a communication signal is sent to the inverter.

15. The method according to claim 14, wherein, When the voltage of the battery module is sufficient to power on the inverter, power is supplied to the inverter.

16. The method of claim 14, wherein, Determining the power outage state of the power grid includes: determining that a fault has occurred in the first communication line when no communication signal provided by the inverter in response to the request signal is received within a preset reference time; and determining that a power outage has occurred in the power grid when the communication signal provided by the inverter in response to the request signal is received within the preset reference time.

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