Energy storage system and operating method thereof

Abstract

An energy storage system according to an embodiment disclosed in the present document comprises: an inverter electrically connected to a grid; a converter which receives, from the inverter, a communication signal and an enable signal related to an operation state of the inverter and is connected to the inverter through a power transmission line; and a controller which determines a power failure of the grid or a power supply state from the inverter to the converter on the basis of the communication signal and the enable signal.

Description

Energy storage system and its operating method

[0001] Cross-citation with related applications

[0002] This invention claims the benefit of priority from Korean Patent Application No. 10-2023-0112144, filed August 25, 2023, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The embodiments disclosed in this document relate to an energy storage system for determining a power outage state of a system and an operating method thereof.

[0005] An Energy Storage System (ESS) is a device that temporarily stores electricity generated by power plants and other sources during periods of low demand, then supplies the stored power to the grid during periods of high demand, thereby promoting efficient power use. Recently, interest in residential ESS, which can store power generated by solar power and other sources, has been growing.

[0006] An energy storage system (ESS) largely includes an inverter connected to the grid, a battery for storing power supplied by the grid, and a converter for performing DC-DC conversion.

[0007] Energy Storage Systems (ESS) perform recovery operations to provide power in case of unexpected power outages or failures. In the event of a power outage or inverter failure, the power stored in the battery must be supplied. However, the converter has difficulty recognizing power outages or inverter problems, requiring the user to activate the ESS to perform recovery operations.

[0008] One purpose of the embodiments disclosed in this document is to provide an energy storage system capable of determining a power outage state of a system and an operating method thereof.

[0009] The technical problems of the embodiments disclosed in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

[0010] An energy storage system according to one embodiment disclosed in this document may include an inverter electrically connected to a grid, a converter that receives a communication signal and an enable signal related to an operating state of the inverter from the inverter, and a controller that is connected to the inverter through a power transmission line, and determines a power outage state of the grid based on the communication signal and the enable signal.

[0011] According to one embodiment, the controller can determine whether the inverter is in an operating state based on the enable signal received through a second communication line connected between the inverter and the converter when the communication signal is not received for a preset threshold time.

[0012] According to one embodiment, the controller may determine that a communication failure state exists between the inverter and the converter when the enable signal is in a logic high state indicating that the inverter is in an operating state, in which the communication signal is not received.

[0013] According to one embodiment, the energy storage system may include a battery module connected to the converter and storing power supplied from the inverter, and the controller may control the battery module and the converter to supply power stored in the battery module to the inverter when the enable signal is in a logic low state indicating that the inverter is not operating.

[0014] In one embodiment, the controller can supply power to the inverter when the voltage of the battery module is sufficient to turn on the power of the inverter.

[0015] According to one embodiment, the controller can determine whether the inverter is in an operating state based on an enable signal received after power is supplied to the inverter.

[0016] In one embodiment, the controller may determine that a failure has occurred in a power supply connected to the inverter and driving the inverter when the enable signal is in a logic low state indicating that the inverter is not operating.

[0017] According to one embodiment, the controller can control the converter to transmit a request signal to the inverter to request a communication signal from the inverter when the enable signal is in a logic high state indicating that the inverter is in an operating state.

[0018] According to one embodiment, the communication signal is received through a first communication line connected between the inverter and the converter, and the controller can determine that a fault has occurred in the first communication line if the communication signal provided by the inverter in response to the request signal is not received within a preset reference time.

[0019] According to one embodiment, the controller may determine that a power outage has occurred in the system if a communication signal provided by the inverter in response to the request signal is received within the reference time.

[0020] An operating method of an energy storage system according to an embodiment disclosed in this document may include a step of determining a communication status between an inverter and a converter, a step of determining an operating status of the inverter based on the communication status, a step of supplying power to the inverter, and a step of determining a power outage status of a system electrically connected to the inverter based on a communication signal received between the inverter and the converter.

[0021] According to one embodiment, the step of determining the communication status between the inverter and the converter may include the step of determining whether a communication signal received through a first communication line connected between the inverter and the converter is received for a preset threshold time period.

[0022] According to one embodiment, the step of determining the operating state of the inverter may include the step of receiving an enable signal related to the operating state of the inverter through a second communication line connected between the inverter and the converter, and the step of determining that a communication error has occurred between the inverter and the converter when the enable signal is in a logic high state.

[0023] According to one embodiment, the step of supplying power to the inverter may include the step of controlling the battery module and the converter to supply power stored in the battery module connected to the converter to the inverter, and the step of determining that a problem has occurred in a power device connected to the inverter and supplying power to the inverter when the enable signal received through the second communication line is in a logic low state, and the step of transmitting a request signal to the inverter for requesting a communication signal from the inverter when the enable signal is in a logic high state.

[0024] In one embodiment, the step of supplying power to the inverter may be performed when the voltage of the battery module is sufficient to turn on power to the inverter.

[0025] According to one embodiment, the step of determining a power outage state of the system may include a step of determining that an abnormality has occurred in the first communication line if a communication signal provided by the inverter in response to the request signal is not received within a preset reference time, and a step of determining that a power outage has occurred in the system if a communication signal provided by the inverter in response to the request signal is received within the preset reference time.

[0026] An energy storage system and its operating method according to an embodiment disclosed in this document can determine a power outage state of a system and supply power to an inverter.

[0027] FIG. 1 is a drawing for explaining an energy storage system and peripheral configuration according to one embodiment disclosed in this document.

[0028] FIG. 2 is a drawing for explaining an energy storage system according to one embodiment disclosed in this document.

[0029] FIG. 3 is a diagram illustrating the operation of an energy storage system and controller over time according to one embodiment disclosed in this document.

[0030] FIG. 4 is a flowchart schematically illustrating the operation of an energy storage device according to an embodiment disclosed in this document.

[0031] FIG. 5 is a flowchart for explaining in detail the operation of an energy storage device according to an embodiment disclosed in this document.

[0032] Hereinafter, embodiments disclosed in this document will be described in detail with reference to exemplary drawings. When designating components in each drawing, it should be noted that, where possible, identical components are given identical reference numerals, even if they appear in different drawings. Furthermore, when describing embodiments disclosed in this document, detailed descriptions of related known structures or functions will be omitted if they are deemed to hinder understanding of the embodiments disclosed in this document.

[0033] In describing the components of the embodiments disclosed in this document, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components and do not limit the nature, order, or sequence of the components. In addition, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the embodiments disclosed in this document belong. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined in this application.

[0034] FIG. 1 is a drawing for explaining an energy storage system and peripheral configuration according to one embodiment disclosed in this document.

[0035] Referring to FIG. 1, an energy storage system (1000) can be electrically connected to a power generation system (10), a system (20), and a load (30).

[0036] The power generation system (10) may be a system that generates electricity using an energy source. The electricity generated by the power generation system (10) may be supplied to an energy storage system (1000). The power generation system (10) may include a solar power generation system, a wind power generation system, a tidal power generation system, etc., but is not limited to these examples. For example, the power generation system (10) may include a system that generates electricity using renewable energy sources such as solar heat, solar light, and geothermal heat.

[0037] The system (20) may refer to a network connected between power producers and power consumers, including a power plant that produces power, a substation that raises or lowers voltage for transmission / distribution, a transmission line that transmits power, and a distribution line that transmits power to power consumers. When the system (20) operates normally, the system (20) can supply power to the energy storage system (1000). In addition, the system (20) can receive power from the energy storage system (1000). When the system (20) does not operate normally, the power supply from the system (20) to the energy storage system (1000) may be interrupted. In addition, the power supply from the energy storage system (1000) to the system (20) may also be interrupted.

[0038] According to an embodiment, a case in which the system (20) does not operate normally may include a case in which a power outage occurs in the system (20).

[0039] A load (30) may consume power produced by a power generation system (10), power stored in an energy storage system (1000), or power supplied from a grid (20). For example, a load (30) may collectively refer to a consumer who consumes power, such as a factory or a home.

[0040] The energy storage system (1000) may include a power conversion unit (1100) and a battery system (1200).

[0041] The power conversion unit (1100) can appropriately convert power when the energy storage system (1000) provides power to the system (20) or the load (30), or when the power generation system (10) provides power to the energy storage system (1000). The power conversion unit (1100) can include a power conversion system (PCS). The power conversion unit (1100) can convert alternating current (AC) power into direct current (DC) power, or convert direct current (DC) power into alternating current (AC) power.

[0042] The battery system (1200) can store power provided by the power generation system (10) or the system (20). When the energy storage system (1000) provides power to the system (20) or the load (30), the energy storage system (1000) can provide power stored in the battery system (1200). The battery system (1200) can include a battery rack, a battery module, a battery pack, etc. capable of storing power.

[0043] FIG. 2 is a drawing for explaining an energy storage system according to one embodiment disclosed in this document.

[0044] Referring to FIG. 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).

[0045] The power conversion unit (1100) can convert power provided by the power generation system (10) or system (20) illustrated in FIG. 1. The power conversion unit (1100) can include an inverter unit (1110).

[0046] The inverter (1111) included in the inverter unit (1110) can convert AC power provided by the power generation system or system (20) into DC power. In addition, the inverter (1111) can convert DC power provided by the battery system (1200) into AC power. The inverter (1111) may be a bidirectional inverter. The power supply unit (1112) can provide power to the inverter (1111) to drive the inverter (1111).

[0047] The battery system (1200) can store power provided by the power generation system (10) or system (20) illustrated in FIG. 1. The battery system (1200) can include a converter unit (1210) and a battery module (1220).

[0048] The converter unit (1210) may include a DC-DC converter (1211) and a controller (1212). The DC-DC converter (1211) may convert the DC power provided from the inverter unit (1110) into DC power to be stored in the battery module (1220), or may convert the DC level of the DC power stored in the battery module (1220) before transmitting it to the system (20) or a load. The DC-DC converter (1211) may be implemented as a linear regulator, etc.

[0049] The inverter unit (1110) and the converter unit (1210) can be connected to each other based on at least one communication line and power transmission line.

[0050] According to an embodiment, the inverter unit (1110) and the converter unit (1210) can be connected to each other through a first communication line, a second communication line, and a power transmission line.

[0051] The first communication line may be a bidirectional communication line connecting the inverter unit (1110) and the converter unit (1210). The inverter unit (1110) may transmit a communication signal to the converter unit (1210) through the first communication line, and the converter unit (1210) may receive a communication signal provided by the inverter unit (1110) through the first communication line.

[0052] According to an embodiment, the first communication line may be a communication line that can check the communication status between the inverter unit (1110) and the converter unit (1210). If a communication signal is not transmitted or received between the inverter unit (1110) and the converter unit (1210) through the first communication line for a preset threshold time, a LOC (Loss of Communication) state may be encountered, in which communication is poor between the inverter unit (1110) and the converter unit (1210).

[0053] According to an embodiment, the communication signal may include a plurality of signals exchanged between the inverter unit (1110) and the converter unit (1210). For example, the communication signal may include a request signal requesting that the converter unit (1210) respond to the inverter unit (1110). In addition, the communication signal may include a heartbeat signal that the inverter unit (1110) provides 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 a communication status between the inverter unit (1110) and the converter unit (1210).

[0054] According to an embodiment, the inverter unit (1110) and the converter unit (1210) may be connected according to the RS-485 communication standard via the first communication line, but are not limited thereto and may be connected by various communication standards, communication standards, or communication protocols.

[0055] The second communication line may be a unidirectional communication line connecting the inverter unit (1110) and the converter unit (1210). That is, the subject transmitting the signal and the subject receiving the signal through the second communication line may not change.

[0056] According to an embodiment, the inverter unit (1110) can transmit a signal through a second communication line, and the converter unit (1210) can receive a signal transmitted by the inverter unit (1110) through the second communication line. The inverter unit (1110) can transmit an enable signal to the converter unit (1210) through the second communication line. The enable signal may be a signal related to the operation of the inverter unit (1110), and may be a signal expressed as 1 bit indicating whether the inverter unit (1110) is operating normally.

[0057] According to an embodiment, when the enable signal is in a logic high state, it may indicate that the inverter unit (1110) is operating normally. Additionally, when the enable signal is in a logic low state, it may indicate that the inverter unit (1110) is not operating normally.

[0058] According to an embodiment, a logic high state may be a state where the bit value is '1', and a logic low state may be a state where the bit value is '0', but is not limited thereto, and depending on the design, a logic high state may be a state where the bit value is '0', and a logic low state may be a state where the bit value is '1'.

[0059] According to an embodiment, a state in which the inverter unit (1110) does not operate normally may include a state in which the inverter unit (1110) does not supply power to the converter unit (1210) through a power transmission line.

[0060] The power transmission line may be a line that transmits power between the inverter unit (1110) and the converter unit (1210). For example, the inverter unit (1110) may appropriately convert power supplied by the system (20) and transmit it to the converter unit (1210) through the power transmission line. The power transmission line may include a switch (not shown).

[0061] According to an embodiment, the power transmission line may be connected to a power supply unit (1112) included in the inverter unit (1110). The power supply unit (1112) may control the power of the inverter (1111) based on the power provided by the converter unit (1210). In addition, the power supply unit (1112) may manage the power provided by the system (20) or the power generation system (10) illustrated in FIG. 1 as a whole.

[0062] According to an embodiment, when the system (20) normally supplies power to the energy storage system (1000) stored in FIG. 1, the connection of the switch (not shown) of the power transmission line may be disconnected.

[0063] According to an embodiment, when a power outage occurs in the system (20) and power stored in the battery module (1220) must be supplied to the system (20), a switch of the power transmission line may be connected.

[0064] The controller (1212) can control the overall operation of the converter unit (1210).

[0065] 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).

[0066] The controller (1212) can control the converter unit (1210) to supply power from the battery module (1220) to the system (20) when a power outage occurs in the system (20). In addition, the controller (1212) can control the converter unit (1210) to supply power to the inverter unit (1110) when the inverter unit (1110) is not operating normally. The operation of the controller (1212) will be described later in the description of FIG. 3.

[0067] FIG. 3 is a diagram illustrating the operation of an energy storage system and controller over time according to one embodiment disclosed in this document.

[0068] Referring to FIG. 3, the operation between components (1111, 1211, 1220) included in the energy storage system over time is illustrated.

[0069] The inverter (1111) can convert AC power provided by the system (20) into DC power. The inverter (1111) can convert AC power into DC power and transmit it to the DC-DC converter (1211).

[0070] The DC-DC converter (1211) can convert the level of the received DC power into a level of DC power that can be stored in the battery module (1220). The DC power converted by the DC-DC converter (1211) can be transmitted to the battery module (1220). The battery module (1220) can store the DC power transmitted by the DC-DC converter (1211).

[0071] Over time, a LOC (Loss of Communication) condition, in which communication is poor, may occur between the inverter (1111) and the DC-DC converter (1211). In an embodiment, the LOC condition may be a condition in which no communication signal is transmitted or received through the first communication line for a preset threshold time.

[0072] The controller (1212) can check an enable signal received from the inverter (1111) when there is no communication signal transmitted or received through the first communication line for a critical time.

[0073] According to an 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 normally operating state, and when the enable signal is in a logic low state, the inverter (1111) may be in a state where it is not operating normally.

[0074] According to an embodiment, when the enable signal is in a logic high state, power may be supplied from the inverter to the converter. When the enable signal is in a logic low state, power may not be supplied from the inverter to the converter.

[0075] When the enable signal is in a logic low state (①), the controller (1212) can determine that the inverter (1111) is not operating normally. The controller (1212) can control the battery module (1220) and the DC-DC converter (1211) to supply power stored in the battery module (1220) to the inverter (1111). 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.

[0076] According to an embodiment, the controller (1212) can check whether the voltage of the battery module (1220) is sufficient to turn on the inverter (1111) when the enable signal is in a logic low state (①). The controller (1212) can control the battery module (1220) and the DC-DC converter (1211) to supply power to the inverter (1111) when the voltage of the battery module (1220) is sufficient to turn on the inverter (1111).

[0077] When the enable signal is in a logic high state (②), the controller (1212) can determine that the inverter (1111) is operating normally. Although the inverter (1111) is operating normally, since no communication signal is transmitted or received through the first communication line for a critical time, the controller (1212) can determine that a communication failure has occurred between the inverter (1111) and the DC-DC converter (1211).

[0078] According to an embodiment, the communication failure condition may include a LOC condition.

[0079] Again, returning to the case where the enable signal is in a logic low state (①), the controller (1212) can check the operating status of the inverter (1111) based on the enable signal received after power is provided to the inverter (1111).

[0080] 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 connected to the inverter (1111) and driving the inverter (1111). This is because sufficient power to turn on the inverter (1111) is transmitted from the battery module (1220), but the inverter (1111) is not operating normally. The power supply may be the power supply (1112) illustrated in FIG. 2.

[0081] When the enable signal is in a logic high state (④), the controller (1212) can control the DC-DC converter (1211) to transmit a request signal to the inverter (1111) through the first communication line.

[0082] According to an embodiment, the request signal may be a signal requesting the DC-DC converter (1211) to respond to the inverter (1111).

[0083] The controller (1212) controls the DC-DC converter (1211) to transmit a request signal to the inverter (1111) and can check whether a communication signal is received within a preset reference time. According to an embodiment, the communication signal may be a heartbeat signal.

[0084] According to an embodiment, the reference time may be 10 seconds, but is not limited thereto, and the reference time may vary depending on the design.

[0085] If a communication signal is received within the reference time (⑤), the controller (1212) can determine that a power outage has occurred in the system (20). If a communication signal is not received within the reference time (⑥), the controller (1212) can determine that a defect has occurred in the first communication line.

[0086] The controller (1212) can detect a power outage occurring in the system (20) through the above process. In addition, the controller (1212) can perform various diagnostic processes in the process of detecting a power outage occurring in the system (20). That is, the controller (1212) can supply power to the inverter (1111) when the inverter (1111) is not operating due to an enable signal, and can determine whether the inverter (1111) is abnormal based on the enable signal received thereafter. In addition, the controller (1212) can control the DC-DC converter (1211) to transmit a request signal, and determine whether the communication line is abnormal based on the received heartbeat signal. Through this, not only can the controller (1212) directly detect a power outage situation in the system (20), but also determine whether there is an abnormality in the inverter (1111), converter (1211), etc. during the process of detecting a power outage in the system (20), and the reliability of detecting a power outage occurring in the system (20) can be increased.

[0087] FIGS. 4 and 5 are flowcharts for explaining the operation of an energy storage device according to one embodiment disclosed in this document.

[0088] FIG. 4 is a flowchart for schematically explaining the operation of an energy storage device according to an embodiment disclosed in this document, and FIG. 5 is a flowchart for detailed explanation of the operation of an energy storage device according to an embodiment disclosed in this document.

[0089] Referring to FIG. 4, at step S401, the energy storage system can determine the communication status between the inverter and the converter.

[0090] According to an embodiment, step S401 may include steps S501 to S505 illustrated in FIG. 5. The energy storage system may check a communication signal received through a first communication line connected between the inverter and the converter (S501), and determine whether a communication signal is received through the first communication line within a threshold time (S503). If a communication signal is transmitted and received between the inverter and the converter through the first communication line (Y), the energy storage system may determine that the communication state between the inverter and the converter is normal (S505). If a communication signal is not transmitted and received between the inverter and the converter through the first communication line (N), step S507 may be performed.

[0091] Referring again to FIG. 4, the energy storage system can check the operating status of the inverter (S403).

[0092] According to an embodiment, step S403 may include steps S507 to S511 illustrated in FIG. 5. The energy storage system may check an enable signal received through a second communication line connected between the inverter and the converter (S507) and check whether the enable signal is in a logic low state (S509). If the enable signal is in a logic high state (N), the energy storage system may determine that a communication error has occurred between the inverter and the converter (S511). If the enable signal is in a logic low state (Y), step S513 may be performed.

[0093] According to an embodiment, the communication anomaly may include a Loss of Communication (LOC) condition.

[0094] Referring again to FIG. 4, the energy storage system can supply power to the inverter (S405).

[0095] According to an embodiment, step S405 may include steps S513 to S521 illustrated in FIG. 5. The energy storage system may transmit power stored in a battery module electrically connected to the converter to an inverter (S513). After transmitting power to the inverter, the energy storage system may check an enable signal received through a second communication line (S517). If the enable signal is in a logic low state (Y), the energy storage system may determine that a problem has occurred in a power supply connected to the inverter (S519). If the enable signal is in a logic high state (N), the energy storage system may transmit a request signal to the inverter to request a communication signal (S521).

[0096] According to an embodiment, the step of transferring power stored in the battery module to the inverter may be performed when the voltage of the battery module is sufficient to turn on the inverter.

[0097] Referring again to FIG. 4, the energy storage system can determine whether there is a power outage in the grid based on a communication signal received between the inverter and the converter (S407).

[0098] According to an embodiment, step S407 may include steps S523 to S527 illustrated in FIG. 5. The energy storage system may determine whether a communication signal provided by the inverter is received within a reference time in response to a request signal (S523). If the communication signal is not received within the reference time (N), the energy storage system may determine that an abnormality has occurred in the first communication line between the inverter and the converter (S525). If the communication signal is received within the reference time (Y), the energy storage system may determine that a power outage has occurred in the grid (S527).

[0099] According to an embodiment, the communication signal transmitted by the inverter in response to the request signal may be a heartbeat signal.

[0100] In the above, all components constituting the embodiments have been described as being combined or operating in combination as one. However, this is not necessarily limited to such embodiments, and within the scope of the purpose, all components may be selectively combined and operated in one or more combinations. Furthermore, terms such as "include," "comprise," or "have" described above, unless specifically stated to the contrary, imply that the corresponding component may be inherent, and therefore should be interpreted to include other components rather than excluding other components.

[0101] The above description is merely an example of the technical idea disclosed in this document, and those skilled in the art to which the embodiments disclosed in this document pertain may make various modifications and variations without departing from the essential characteristics of the embodiments disclosed in this document.

[0102] Accordingly, the embodiments disclosed in this document are intended to illustrate, rather than limit, the technical concepts disclosed in this document, and the scope of the technical concepts disclosed in this document is not limited by these embodiments. The scope of protection of the technical concepts disclosed in this document should be interpreted by the claims below, and all technical concepts within the equivalent scope should be interpreted as being included within the scope of the rights of this document.

[0103] [Explanation of symbols]

[0104] 10: Power generation system 20: Grid

[0105] 30: Load 1000: Energy storage system

[0106] 1100: Power conversion unit 1110: Inverter unit

[0107] 1111: Inverter 1112: Power supply

[0108] 1200: Battery system 1210: Converter section

[0109] 1211: DC-DC converter 1212: controller

[0110] 1220: Battery module

Claims

1. Inverter electrically connected to the grid; A converter that receives a communication signal and an enable signal related to the operating status of the inverter from the inverter and is connected to the inverter through a power transmission line; and An energy storage system comprising a controller that determines a power outage state of the system based on the communication signal and the enable signal.

2. In the first paragraph, the controller, An energy storage system that determines whether the inverter is in an operating state based on the enable signal received through a second communication line connected between the inverter and the converter when the communication signal is not received for a preset threshold time.

3. In the second paragraph, the controller, An energy storage system that determines that a communication failure state is a state in which the communication signal is not received between the inverter and the converter when the enable signal is in a logic high state indicating that the inverter is in an operating state.

4. In paragraph 2, Further comprising a battery module connected to the converter and storing power supplied from the inverter; The above controller, If the above enable signal is in a logic low state indicating that the inverter is not operating, An energy storage system that controls the battery module and the converter to supply power stored in the battery module to the inverter.

5. In the fourth paragraph, the controller, An energy storage system that supplies power to the inverter when the voltage of the battery module is sufficient to turn on the power of the inverter.

6. In the fourth paragraph, the controller, An energy storage system that determines whether the inverter is in an operating state based on an enable signal received after power is supplied to the inverter.

7. In the 6th paragraph, the controller, If the enable signal received after the above power is supplied is in a logic low state indicating that the inverter is not operating, An energy storage system that determines that a failure has occurred in a power supply device connected to the inverter and driving the inverter.

8. In the 6th paragraph, the controller, If the enable signal received after the above power is supplied is in a logic high state indicating that the inverter is in an operating state, An energy storage system that controls the converter to transmit a request signal to the inverter for requesting a communication signal from the inverter.

9. In paragraph 8, The above communication signal is received through a first communication line connected between the inverter and the converter, The above controller, An energy storage system that determines that a fault has occurred in the first communication line when a communication signal provided by the inverter in response to the request signal is not received within a preset reference time.

10. In the 8th paragraph, the controller, An energy storage system that determines that a power outage has occurred in the grid when a communication signal provided by the inverter in response to the request signal is received within a critical time.

11. Step for determining the communication status between the inverter and converter; A step of determining the operating status of the inverter based on the communication status; A step of supplying power to the above inverter; and An operating method of an energy storage system, comprising: a step of determining a power outage state of a system electrically connected to the inverter based on a communication signal received between the inverter and the converter.

12. In the 11th paragraph, the step of determining the communication status between the inverter and the converter is: An operating method of an energy storage system, comprising a step of determining whether a communication signal received through a first communication line connected between the inverter and the converter is received for a preset threshold time period.

13. In the 12th paragraph, the step of determining the operating status of the inverter is: A step of receiving an enable signal related to the operating state of the inverter through a second communication line connected between the inverter and the converter; and An operating method of an energy storage system, comprising: a step of determining that a communication error has occurred between the inverter and the converter when the enable signal is in a logic high state.

14. In the 13th paragraph, the step of supplying power to the inverter is: A step of controlling the battery module and the converter to supply power stored in the battery module connected to the converter to the inverter; and An operating method of an energy storage system, comprising: a step of determining that a problem has occurred in a power supply device connected to the inverter and supplying power to the inverter when the enable signal received through the second communication line is in a logic low state, and a step of transmitting a request signal to the inverter for requesting a communication signal from the inverter when the enable signal is in a logic high state.

15. In the 14th paragraph, the step of supplying power to the inverter is: An operating method of an energy storage system performed when the voltage of the battery module is sufficient to turn on the power of the inverter.

16. In the 14th paragraph, the step of determining the power outage status of the system is: An operating method of an energy storage system, comprising: a step of determining that an abnormality has occurred in the first communication line if a communication signal provided by the inverter in response to the request signal is not received within a preset reference time; and a step of determining that a power outage has occurred in the system if a communication signal provided by the inverter in response to the request signal is received within the preset reference time.

Images