Energy storage system

Abstract

The aim is to provide an energy storage system that can continue supplying power to facilities equipped with batteries as much as possible even after an earthquake, and that can prevent accidents caused by electrical leakage or short circuits as much as possible, even if electrical equipment is damaged by the earthquake. [Solution] The energy storage system performs a charging and discharging stop process for the battery 15, a tripping operation instruction process that outputs information to the user prompting them to open the main breaker 4, the energy storage device breaker 5a, and the load breakers 5b and 5c, and to turn off the power switch 25a on the power load 25, and after performing a discharge start process, it performs a power supply operation instruction process that outputs information to the user prompting them to close the energy storage device breaker 5a and the load breakers 5b and 5c, and if it is determined that the discharge current from the battery 15 satisfies the abnormal current condition, it performs an abnormality confirmation process that stops the discharge operation.

Description

Technical Field

[0001] The present invention relates to a power storage system.

Background Art

[0002] A power storage system has been proposed in which a power storage device is installed in facilities such as residential houses and business establishments, and power can be supplied from the power storage device to a power load even when a power outage occurs due to an earthquake. For example, Patent Document 1 (Japanese Patent No. 7109861) describes a system including a storage battery (53). This system includes a switching device (18) that switches the power supply source for loads (32) related to disaster prevention, crime prevention, and medical care, which are desired to maintain power supply even after an earthquake, to either the commercial power supply (91) or the storage battery (53). Then, when a power outage signal indicating that the power supply to the secondary side of the main breaker (15) has been interrupted is output to the switching device (18), the switching device (18) immediately switches the power supply source for the load (32) to the storage battery (53). Thereby, even when a power outage occurs due to an earthquake, power supply to the load (32) is performed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the event of an earthquake, electrical equipment installed in facilities such as residences and offices may be damaged. If power is supplied to the damaged electrical equipment, accidents may occur due to leakage or short circuits from the damaged parts. In the system described in Patent Document 1, even if a power outage occurs, the power supply from the storage battery (53) to the load (32) is unconditionally started by the switching device (18), so if the electrical equipment is damaged, leakage or short circuits may occur from the damaged parts.

[0005] This invention has been made in view of the above-mentioned problems, and its purpose is to provide an energy storage system that can continue to supply power to facilities equipped with batteries as much as possible even after an earthquake occurs, and that can prevent accidents caused by leakage or short circuits as much as possible even if electrical equipment is damaged by the earthquake. [Means for solving the problem]

[0006] A characteristic configuration of the energy storage system according to the present invention for achieving the above objective is an energy storage system comprising an energy storage device connected to a power line connected to a power grid, The energy storage device comprises a battery, a power controller that controls the discharge operation from the battery and the charging operation to the battery, and a control unit that controls the operation of the power controller. A circuit breaker for the energy storage device that connects the energy storage device to the power line, A load breaker that connects a power load to the power line, A main circuit breaker located upstream of the aforementioned energy storage device breaker and installed on the aforementioned power line, An information output unit that outputs information to the user, The earthquake-related information acquisition unit acquires information related to earthquakes, The system includes an input receiving unit that receives operation input from the user, The control unit, referring to the information acquired by the earthquake-related information acquisition unit, determines that an earthquake of a strength equal to or greater than a first predetermined value has occurred or is likely to occur in the area where the energy storage device is installed. The system performs a charge / discharge stop process that causes the power controller to stop the discharge operation from the battery and the charging operation to the battery, and a tripping operation instruction process that causes the main circuit breaker, the circuit breaker for the energy storage device, and the circuit breaker for the load to be opened, and outputs information from the information output unit to the user to prompt them to turn off the power switch on the power load. When predetermined discharge start conditions are met, including the execution of the charge / discharge stop process and the cutoff operation instruction process and the acceptance of the input unit receiving an operation input from the user, a discharge start process is executed to cause the power controller to start the discharge operation from the storage battery. After performing the discharge start process, the power supply operation instruction process is performed, which outputs information from the information output unit to the user to prompt them to close the circuit breaker for the energy storage device and the circuit breaker for the load. The key feature is that, before or after executing the power supply operation instruction process, if it is determined that an abnormal current condition is met, such as the maximum absolute value of the discharge current from the battery to each of the voltage lines constituting the power line, or the absolute value of the sum of the discharge currents to each of the voltage lines, continuously exceeding the respective threshold current, an abnormality confirmation process is executed to stop the discharge operation from the battery by the power controller.

[0007] Here, the control unit may determine that the discharge start condition has been met when the input receiving unit receives an operation input from the user indicating that the user has opened the main circuit breaker, the energy storage device circuit breaker, and the load circuit breaker in response to the tripping operation instruction process, and has turned off the power switch on the power load. Furthermore, the control unit may determine that the discharge start condition has been met when the input receiving unit receives an operation input from the user indicating that the user has opened the main circuit breaker, the circuit breaker for the energy storage device, and the circuit breaker for the load in response to the tripping operation instruction process, and has turned off the power switch on the power load, and when the input receiving unit receives an operation input from the user regarding the identification information assigned to the user of the energy storage device. Furthermore, if the earthquake-related information acquisition unit acquires information on an early earthquake warning targeting the area where the energy storage device is installed, the control unit may determine that an earthquake of a strength equal to or greater than the predetermined value has occurred or is likely to occur in the area where the energy storage device is installed. Furthermore, if the earthquake-related information acquisition unit acquires information regarding a tsunami warning or tsunami advisory for the area where the energy storage device is installed, the control unit may determine that an earthquake of a strength equal to or greater than the predetermined value has occurred or is likely to occur in the area where the energy storage device is installed. Furthermore, considering that an earthquake may prevent communication with other devices via the internet, the control unit may determine that an earthquake of a strength equal to or greater than the predetermined value has occurred or is likely to occur in the area where the energy storage device is installed if it becomes impossible to communicate with other devices via the internet.

[0008] According to the above characteristic configuration, if the control unit determines that an earthquake of a strength exceeding a predetermined value has occurred or is likely to occur in the area where the energy storage device is installed, it executes a charge / discharge stop process that instructs the power controller to stop the discharge operation from the battery and the charging operation to the power lines. In addition, the control unit executes the above charge / discharge stop process, a tripping operation instruction process that opens the main breaker, the breaker for the energy storage device, and the breaker for the load, and outputs information from the information output unit to the user to prompt them to turn off the power switch on the power load, and if predetermined discharge start conditions are met, including the condition that the input reception unit has received operation input from the user, it executes a discharge start process that instructs the power controller to start the discharge operation from the battery. In other words, the discharge operation from the battery will not start unless the discharge start condition, which includes the condition that the input reception unit receives operation input from the user, is met. This means that power supply from the battery to the power load will not start unconditionally as in the past. Therefore, even if there is damage to the parts electrically connected to the battery, it is more likely that the user can prevent leakage or short circuits caused by current flow from the battery at the damaged part. For example, if there is damage that the user can confirm, the user can prevent the discharge start condition from being met and thus prevent power supply from starting from the battery to the power load.

[0009] Furthermore, the control unit opens the main circuit breaker, the energy storage device circuit breaker, and the load circuit breaker, and turns off the power switch on the power load, thereby initiating the discharge operation from the battery in a state where power should not be supplied from the battery to the power load. Then, before or after executing the power supply operation instruction process, which outputs information from the information output unit to the user to prompt the user to close the energy storage device circuit breaker and the load circuit breaker while the main circuit breaker is open and the power switch on the power load is off, if the control unit determines that an abnormal current condition is met, where the maximum absolute value of the discharge current from the battery to each of the voltage lines constituting the power line, or the absolute value of the sum of the discharge currents to each of the voltage lines, continuously exceeds the respective threshold current, it executes an abnormality confirmation process to stop the discharge operation from the battery to the power controller. In other words, the control unit executes the abnormality confirmation process if the discharge current is at a level that can be considered to be due to leakage or short circuit. Therefore, it is possible to provide an energy storage system that can continue to supply power to facilities equipped with batteries as much as possible even after an earthquake, and that can prevent accidents caused by electrical leakage or short circuits as much as possible, even if electrical equipment is damaged by the earthquake.

[0010] Another characteristic configuration of the energy storage system according to the present invention is that it includes a power outage information acquisition unit that acquires information indicating whether or not there is an abnormal state in which power is not being supplied from the power system to the power line, and the control unit, by referring to the information acquired by the earthquake-related information acquisition unit, determines that an earthquake of a strength of the first predetermined value or more has occurred or is about to occur in the area where the energy storage device is installed, and if the power outage information acquisition unit has acquired information indicating the abnormal state, it executes the charge / discharge stop process and the cutoff operation instruction process.

[0011] According to the above-described configuration, in the event of an abnormal situation where power is not being supplied normally from the power system to the power lines, i.e., a power outage, it is possible to execute both a charge / discharge stop process and a cutoff operation instruction process.

[0012] Another characteristic configuration of the energy storage system according to the present invention is that, in the abnormality confirmation process, the control unit measures the discharge current from the battery to the power line a predetermined number of times after the power controller has started the discharge operation from the battery, with a period in between during which the power controller is not allowed to discharge from the battery. The control unit determines that the abnormal current condition is met if, even after measuring the discharge current a predetermined number of times, the maximum value of the absolute value of the discharge current to each of the voltage lines or the absolute value of the sum of the discharge currents to each of the voltage lines is equal to or greater than the respective threshold current.

[0013] When a capacitor-input type power load is connected to the power supply from a battery, a large current may temporarily flow immediately after the battery discharges, even if no short circuit occurs (i.e., the maximum absolute value of the discharge current to each voltage line may exceed its threshold current). However, such a large current will not flow after charge has accumulated in the capacitor. Therefore, in this feature configuration, the control unit, in the abnormality confirmation process, measures the discharge current from the battery to the power lines a predetermined number of times after the power controller has started the discharge operation from the battery, with a period in between during which the power controller does not perform the discharge operation from the battery. After measuring the discharge current a predetermined number of times, if the maximum absolute value of the discharge current to each voltage line or the absolute value of the sum of the discharge currents to each voltage line is greater than or equal to the respective threshold current, the control unit determines that the above abnormal current condition is met. In other words, it is possible to distinguish between the phenomenon of a large current flowing temporarily in a capacitor-input type power load and a short circuit in which a large current flows continuously.

[0014] Another characteristic configuration of the energy storage system according to the present invention is that the control unit performs the abnormality confirmation process and outputs information from the information output unit to the user to make the user aware that there is an abnormality in the discharge current.

[0015] According to the above feature configuration, it is possible to notify the user if there is an abnormality.

[0016] Another characteristic configuration of the power storage system according to the present invention is that, even while the abnormality confirmation process is not being executed, if the maximum value of the absolute value of the discharge current from the storage battery to each of the voltage lines or the absolute value of the total value of the discharge current to each of the voltage lines is greater than or equal to each of the threshold currents, the power controller is made to stop the discharge operation from the storage battery. The threshold current during the execution of the abnormality confirmation process is set to a value smaller than the threshold current during the period when the abnormality confirmation process is not being executed.

[0017] According to the above characteristic configuration, it is possible to surely find a state in which the maximum value of the absolute value of the discharge current from the storage battery to each of the voltage lines or the absolute value of the total value of the discharge current to each of the voltage lines is greater than or equal to each of the threshold currents, that is, a state in which there is a high possibility of leakage or short circuit.

[0018] Another characteristic configuration of the power storage system according to the present invention is that, when the earthquake-related information acquisition unit acquires the Nankai Trough earthquake temporary information (major earthquake warning) or the Nankai Trough earthquake temporary information (major earthquake caution), the control unit causes the power controller to start the charging operation of the storage battery and executes a charging promotion process for stopping the discharge operation from the storage battery by the power controller until a predetermined discharge permission condition is satisfied. [[ID=I]]Here, when the earthquake-related information acquisition unit receives the Nankai Trough earthquake temporary information (investigation completed), or after a set period has elapsed since the earthquake-related information acquisition unit received the Nankai Trough earthquake temporary information (investigation completed), the control unit can end the charging promotion process.

[0019] According to the above characteristic configuration, after the Nankai Trough earthquake temporary information (major earthquake warning) or the Nankai Trough earthquake temporary information (major earthquake caution) is announced, the charging rate (SOC: State Of Charge) of the storage battery can be increased. As a result, even if an earthquake actually occurs and power supply from the power grid cannot be received, sufficient power supply can be received from the storage battery with an increased charging rate.

[0020] Another characteristic configuration of the power storage system according to the present invention is that the control unit causes the power controller to perform a charging operation from the power line so that the charging rate of the storage battery does not exceed a predetermined upper limit charging rate. The upper limit charging rate during the execution of the charging promotion process is set higher than the upper limit charging rate during the period when the charging promotion process is not being executed.

[0021] According to the above characteristic configuration, after the release of the Nankai Trough Earthquake Temporary Information (Great Earthquake Warning) or the Nankai Trough Earthquake Temporary Information (Great Earthquake Attention), the charging rate of the storage battery can be increased compared to the case where the charging promotion process is not being executed.

[0022] Another characteristic configuration of the power storage system according to the present invention is that when the earthquake-related information acquisition unit acquires information indicating that an earthquake with a magnitude of 2 or more has occurred in the area where the power storage device is installed during the execution of the charging promotion process, the control unit determines that the discharge permission condition is satisfied and executes a discharge promotion process that permits the power controller to perform a discharge operation from the storage battery.

[0023] According to the above characteristic configuration, when an earthquake actually occurs, the amount of power charged in the storage battery by the charging promotion process can be used for the power load.

[0024] Another characteristic configuration of the power storage system according to the present invention is that the control unit causes the power controller to perform a discharge operation from the storage battery so that the charging rate of the storage battery does not fall below a predetermined lower limit charging rate. The lower limit charging rate during the execution of the discharge promotion process is set lower than the lower limit charging rate during the period when the discharge promotion process is not being executed.

[0025] According to the above characteristic configuration, when using the amount of power charged in the storage battery by the charging promotion process for the power load after an earthquake actually occurs, more power can be used compared to the case where the discharge promotion process is not being executed.

[0026] Another characteristic configuration of the energy storage system according to the present invention is that the control unit outputs from the information output unit information about the operations that the user needs to perform before executing the cutoff operation instruction process, or when executing the cutoff operation instruction process and in order for the discharge start process to be executed.

[0027] According to the above-described configuration, the discharge start process can be reliably carried out by outputting information about the operations that the user needs to perform from the information output unit. [Brief explanation of the drawing]

[0028] [Figure 1] A diagram showing the configuration of an energy storage system. [Figure 2] This is a flowchart explaining the processes performed in an energy storage device. [Figure 3] This is a diagram showing the configuration of an energy storage system in a different embodiment. [Modes for carrying out the invention]

[0029] An embodiment of the present invention of an energy storage system will be described below with reference to the drawings. Figure 1 shows the configuration of an energy storage system. As shown in the figure, the energy storage system includes an energy storage device 10 connected to a power line 2 connected to a power system 1. A distribution board 3 is provided on the power line 2. The power line 2 is, for example, a single-phase three-wire system. In the distribution board 3, a main breaker 4 is provided on the upstream side (power system 1 side), and several breakers 5 are provided downstream of it. For example, the distribution board 3 is provided with an energy storage device breaker 5a that connects the energy storage device 10 to the power line 2, and load breakers 5b and 5c that connect the power load 25 to the power line 2. In other words, the main breaker 4 is located on the power system 1 side of the power line 2, beyond the connection point of the energy storage device breaker 5a and the connection points of the load breakers 5b and 5c (i.e., the main breaker 4 is located upstream of the energy storage device breaker 5a and on the power line 2). The number of load breakers 5b and 5c can be changed as appropriate.

[0030] The power load 25 is connected to the load breaker 5c. Figure 1 also shows an example where a power switch 25a is provided on the power load 25 to switch the power supply on and off. However, there are also power loads 25, such as refrigerators, that do not have a power switch 25a, and power supply starts and operation begins simply by plugging the electrical plug into an electrical outlet.

[0031] The energy storage device 10 is connected to the energy storage device circuit breaker 5a. The energy storage device 10 includes a battery 15, a power controller 12 that controls the discharge operation from the battery 15 and the charging operation to the battery 15, and a control unit 16 that controls the operation of the power controller 12. In addition, the energy storage device 10 of this embodiment includes a grid connection protection relay 11 that connects the power controller 12 and the energy storage device circuit breaker 5a. Furthermore, the energy storage device 10 includes an earthquake-related information acquisition unit 17, a power outage information acquisition unit 18, a storage unit 19 that stores information handled by the energy storage device 10, an information output unit 20, and an input reception unit 21.

[0032] When charging the battery 15 from the power line 2, the control unit 16 instructs the power controller 12 to perform the charging operation from the power line 2 to the battery 15 so that the charge level (SOC: State of Charge) of the battery 15 does not exceed a predetermined upper limit charge level. Similarly, when discharging from the battery 15 to the power line 2, the control unit 16 instructs the power controller 12 to perform the discharging operation from the battery 15 to the power line 2 so that the charge level of the battery 15 does not fall below a predetermined lower limit charge level.

[0033] A current measuring unit 6, which measures the current supplied from the power system 1, and a voltage measuring unit 7, which measures the voltage of the power supplied from the power system 1, are installed on the power line 2 upstream of the main breaker 4. The measurement results from the current measuring unit 6 and the voltage measuring unit 7 are transmitted to the energy storage device 10.

[0034] The control unit 16 can determine the power received from power system 1, or the power flowing back to power system 1, by multiplying the current measured by the current measurement unit 6 by the voltage measured by the voltage measurement unit 7. If it is necessary to prevent power flowing back to power system 1, the control unit 16 can refer to the measurement results of the current measurement unit 6 and the voltage measurement unit 7 and adjust the discharge power from the battery 15 to the power line 2 using the power controller 12 so that the power received from power system 1 becomes a positive value.

[0035] The energy storage device 10 can communicate with external devices via an information and communication network 8, such as the Internet. Figure 1 shows a configuration in which the energy storage device 10 can communicate with an information provision server 9. The information provision server 9 is composed of one or more devices. For example, the information provision server 9 may differ depending on the type of information to be provided.

[0036] The earthquake-related information acquisition unit 17 acquires information related to earthquakes. For example, if the energy storage device 10 is equipped with an acceleration sensor, that acceleration sensor, which can measure the strength of an earthquake, functions as the earthquake-related information acquisition unit 17. Alternatively, the earthquake-related information acquisition unit 17 may acquire information from the information provision server 9 as earthquake-related information, such as information combining the name of the area where the shaking occurred and the strength of the earthquake (e.g., seismic intensity, SI value, long-period ground motion class, etc.), information on earthquake early warnings, information on tsunami warnings or advisories, Nankai Trough earthquake temporary information (large earthquake alert), Nankai Trough earthquake temporary information (large earthquake warning), and Nankai Trough earthquake temporary information (investigation completed). Alternatively, the earthquake-related information acquisition unit 17 may acquire information indicating that, if a microcomputer meter for gas supply is installed in the facility where the energy storage device 10 is installed, the microcomputer meter has detected an earthquake and shut off the gas supply (i.e., an earthquake of a strength equal to or greater than the first predetermined value has occurred), or information indicating that the gas supply has not been shut off (i.e., an earthquake of a strength equal to or greater than the first predetermined value has not occurred).

[0037] The power outage information acquisition unit 18 acquires the measurement results from the voltage measurement unit 7 as information indicating whether or not there is an abnormal state in which power is not being supplied normally from the power system 1 to the power line 2. Then, if the voltage information of the power measured by the voltage measurement unit 7 satisfies predetermined power outage conditions (for example, if the voltage information is processed by the control unit 16 and exceeds the threshold for detecting islanding), the power outage information acquisition unit 18 determines that there is an abnormal state in which power is not being supplied normally from the power system 1 to the power line 2 (i.e., a power outage has occurred in the power system 1), and disconnects the energy storage device 10 from the power line 2 by opening the interconnection protection relay 11. The power outage information acquisition unit 18 may acquire information other than the measurement results from the voltage measurement unit 7 as information indicating whether or not there is an abnormal state.

[0038] The information output unit 20 outputs information to the user of the energy storage device 10 in the form of voice, text, light, etc. The input receiving unit 21 receives operation input from the user of the energy storage device 10. Figure 1 shows the information output unit 20 and the input receiving unit 21 included in the energy storage device 10, but the information output unit 20 and the input receiving unit 21 may be provided in a separate device from the energy storage device 10. For example, the information output unit 20 and the input receiving unit 21 may be implemented using a remote control provided in a facility such as a dwelling or business office where the energy storage device 10 is installed, and the remote control may be connected to the energy storage device 10 in a manner that allows communication. Alternatively, the information output unit 20 and the input receiving unit 21 may be implemented using an information terminal such as a smartphone used by the facility's users, and the information terminal may be connected to the energy storage device 10 in a manner that allows communication.

[0039] The power controller 12 comprises two power conversion circuit units 13 and 14. Inside the power controller 12, the power conversion circuit units 13 and 14 are connected in parallel to the battery 15. Specifically, power conversion circuit unit 13 connects the grid-connection protection relay 11 and the battery 15 to perform power conversion from AC power to DC power and from DC power to AC power. Power conversion circuit unit 14 connects the control unit 16, earthquake-related information acquisition unit 17, power outage information acquisition unit 18, storage unit 19, information output unit 20, and input reception unit 21 to the battery 15 to perform power conversion from DC power to DC power.

[0040] The control unit 16 of the energy storage device 10, referring to the information acquired by the earthquake-related information acquisition unit 17, determines that an earthquake of a strength of 1 predetermined value or more has occurred or is likely to occur in the area where the energy storage device 10 is installed, and executes a charge / discharge stop process that causes the power conversion circuit unit 13 of the power controller 12 to stop the discharge operation from the storage battery 15 and the charging operation to the storage battery 15, and a tripping operation instruction process that causes the main breaker 4, the energy storage device breaker 5a, and the load breakers 5b and 5c to be opened (i.e., electrically disconnected), and outputs information from the information output unit 20 to the user to prompt them to turn off the power switch 25a on the power load 25. If the predetermined discharge start conditions are met, which include the conditions that the charge / discharge stop process and the tripping operation instruction process have been executed and the input reception unit 21 has received an operation input from the user, the energy storage device 10 will start. The system executes a discharge start process to instruct the power controller 12's power conversion circuit section 13 to begin discharging from the battery 15. After executing the discharge start process, it executes a power supply operation instruction process to output information from the information output section 20 to the user to prompt them to close the energy storage device breaker 5a (i.e., to make it electrically connected) and to close the load breakers 5b and 5c. Before or after executing the power supply operation instruction process, if it is determined that an abnormal current condition is met, where the maximum absolute value of the discharge current from the battery 15 to each of the voltage lines (not shown) constituting the power line 2, or the absolute value of the sum of the discharge currents to each of the voltage lines, continuously exceeds the respective threshold current, an abnormality confirmation process is executed to instruct the power controller 12's power conversion circuit section 13 to stop the discharge operation from the battery 15. The following describes in detail the contents of each process performed by the control unit 16 of the energy storage device 10.

[0041] Figure 2 is a flowchart illustrating the processes performed by the energy storage device 10. The control unit 16 starts the flowchart in Figure 2 when it determines, based on the information acquired by the earthquake-related information acquisition unit 17, that an earthquake of a strength equal to or greater than a first predetermined value has occurred or is likely to occur in the area where the energy storage device 10 is installed. For example, the control unit 16 can determine whether or not an earthquake of a strength equal to or greater than a first predetermined value has occurred in the area where the energy storage device 10 is installed, based on information acquired by the earthquake-related information acquisition unit 17 that combines the name of the area where the shaking occurred and the strength of the earthquake (e.g., seismic intensity, SI value, long-period ground motion class, etc.).

[0042] Furthermore, if the earthquake-related information acquisition unit 17 acquires information on an early earthquake warning targeting the area where the energy storage device 10 is installed, the control unit 16 may determine that an earthquake of a strength equal to or greater than a first predetermined value has occurred or is likely to occur in the area where the energy storage device 10 is installed.

[0043] Alternatively, if the earthquake-related information acquisition unit 17 acquires information regarding a tsunami warning or tsunami advisory for the area where the energy storage device 10 is installed, the control unit 16 may determine that an earthquake of a strength equal to or greater than a first predetermined value has occurred or is likely to occur in the area where the energy storage device 10 is installed.

[0044] Alternatively, if the control unit 16 becomes unable to communicate with other devices via an information and communication network 8 such as the Internet, it may determine that an earthquake of a strength equal to or greater than a first predetermined value has occurred or is likely to occur in the area where the energy storage device 10 is installed.

[0045] In step #10, the control unit 16 stops the charging and discharging of the battery 15, that is, it performs a charge / discharge stop process that stops the discharge operation from the battery 15 to the power line 2 and the charging operation from the power line 2 to the battery 15 in the power controller 12's power conversion circuit unit 13. In addition, the control unit 16 outputs information to the user from the information output unit 20 indicating that the charging and discharging of the battery 15 has stopped. As a result, the user can recognize that the charging and discharging of the battery 15 has stopped.

[0046] In addition, in step #10, the control unit 16 may open the main circuit breaker 4. When the main circuit breaker 4 is opened, the energy storage device 10 and the power load 25 are disconnected from the power system 1.

[0047] In step #11, the control unit 16 outputs the earthquake-related information acquired by the earthquake-related information acquisition unit 17 to the user via the information output unit 20. As a result, the user can recognize that the charging and discharging of the storage battery 15 has stopped due to the earthquake.

[0048] In step #12, the control unit 16 outputs the procedure for starting power supply from the battery 15 to the user via the information output unit 20. For example, the control unit 16 outputs to the user via the information output unit 20 that it is necessary to perform procedures such as authenticating the user of the energy storage device 10, requesting to restart operation, and performing an operation to stop power supply to the power load 25. As a result, the user can recognize the procedures necessary for power supply from the battery 15 to be restarted.

[0049] In step #13, the control unit 16 determines whether or not user authentication has been completed. If authentication is completed, the control unit 16 proceeds to step #14; otherwise, it repeats step #13. For example, the control unit 16 outputs a message to the user from the information output unit 20 requesting the user to enter a PIN, and if the PIN received by the input reception unit 21 from the user matches a correct PIN stored in the storage unit 19, the control unit 16 determines that user authentication has been completed. By following these steps, the control unit 16 can determine that a legitimate user is involved in restarting the power supply from the battery 15.

[0050] In step #14, the control unit 16 determines whether or not a request for restarting operation has been received from the user, that is, a request for the power supply from the energy storage device 10 to the power load 25 to be resumed. For example, if the control unit 16 receives an operational input from the user, such as the "restart operation" button on the input reception unit 21, it determines that a request for restarting operation has been received from the user.

[0051] In step #15, the control unit 16 starts measuring time. As will be described later, the control unit 16 is configured not to supply power from the battery 15 until the shortest required time has elapsed before power supply from the battery 15 can be started.

[0052] In step #16, the control unit 16 outputs to the user from the information output unit 20 an operation to stop the power supply to the power load 25 (power supply stop operation). Specifically, the control unit 16 performs a stop operation instruction process that outputs information from the information output unit 20 to the user to prompt them to open the main breaker 4, the energy storage device breaker 5a, and the load breakers 5b and 5c, and to turn off the power switch 25a on the power load 25. In other words, when the power supply stop operation is performed, such as opening the energy storage device breaker 5a, opening the load breakers 5b and 5c, and turning off the power switch 25a, the power supply to the power load 25 is reliably stopped.

[0053] In step #17, the control unit 16 determines whether or not an input has been received indicating that a power supply termination operation has been performed. If the input receiving unit 21 has received an input from the user indicating that a power supply termination operation has been performed, the control unit 16 proceeds to step #18.

[0054] In process #18, the control unit 16 uses the information output unit 20 to instruct the user on the inspection points to be checked before starting the power supply. In other words, the control unit 16 outputs information from the information output unit 20 about the operations that the user needs to perform in order for the discharge start process, which will be described later, to be executed. The control unit 16 may output the inspection points to be checked before starting the power supply to the user either before or after executing the cutoff operation instruction process. It is expected that if the user is instructed on the inspection points in this way and takes the time to faithfully perform the inspection, any abnormalities in the electrical equipment will be detected.

[0055] In step #19, the control unit 16 determines whether or not input has been received indicating that the inspection was successful and no problems were found. If the input receiving unit 21 receives input from the user indicating that the inspection was successful and no problems were found, the control unit 16 proceeds to step #20. In other words, the user verifies the soundness of the electrical equipment.

[0056] In step #20, the control unit 16 determines whether a predetermined amount of time has elapsed since the start of time measurement in step #15. Specifically, the control unit 16 determines whether the elapsed time since the start of time measurement in step #15 is equal to or greater than the minimum required time. If the elapsed time is equal to or greater than the minimum required time, the control unit 16 proceeds to step #21. As described above, the user is given instructions in step #18 regarding the inspection points of the electrical equipment, and if the user faithfully performs the inspection over a sufficient period of time, a certain amount of time will be required. However, if the user does not faithfully perform the inspection, it may take only a short time from step #15 to step #20. Therefore, in step #15, in order to confirm that the user faithfully performed the inspection over a sufficient period of time, it is determined whether the elapsed time since the start of time measurement in step #15 is equal to or greater than the minimum required time.

[0057] In step #21, the control unit 16 starts supplying power from the battery 15. That is, the control unit 16 executes a discharge start process to cause the power conversion circuit section 13 of the power controller 12 to start the discharge operation from the battery 15 (i.e., the discharge operation from the battery 15 to the breaker 5a for the energy storage device). Here, the control unit 16 makes the upper limit threshold of the absolute value of the discharge current during the discharge start process smaller than the upper limit threshold of the absolute value of the discharge current when the discharge start process is not being performed. By making the upper limit threshold of the absolute value of the discharge current smaller, even if a short circuit occurs, a large current cannot flow rapidly.

[0058] As described above, in this embodiment, the control unit 16 determines that the discharge start condition has been met when the input receiving unit 21 receives an operation input from the user regarding identification information assigned to the user of the energy storage device 10 (Yes in step #13), the input receiving unit 21 receives an operation input from the user regarding information indicating that the user has opened the main breaker 4, the energy storage device breaker 5a, and the load breakers 5b and 5c in response to the tripping operation instruction process, and has turned off the power switch 25a on the power load 25 (Yes in step #17), the input receiving unit 21 receives an input from the user indicating that there were no problems with the inspection points instructed to the user (Yes in step #19), and the elapsed time since the start of time measurement in step #15 is equal to or greater than the minimum required time (Yes in step #20).

[0059] Subsequently, in step #22, the control unit 16 instructs the user to perform an operation to start supplying power to the power load 25 (power supply operation). Specifically, after performing the discharge start process, the control unit 16 performs a power supply operation instruction process, which outputs information from the information output unit 20 to the user to prompt them to close the breaker 5a for the energy storage device and to close the breakers 5b and 5c for the load. At this point, the user may be instructed to close the breakers 5b and 5c for the load, and to turn on the power switch 25a at the same time. In other words, once power supply operations such as closing the breaker 5a for the energy storage device, closing the breakers 5b and 5c for the load, and turning on the power switch 25a are performed, power supply from the battery 15 to the power load 25 begins.

[0060] Next, before or after executing the power supply operation instruction process, if the control unit 16 determines that an abnormal current condition is met, such as the maximum absolute value of the discharge current from the battery 15 to each of the voltage lines constituting the power line 2, or the absolute value of the sum of the discharge currents to each of the voltage lines continuously exceeding the respective threshold current, it executes an abnormality confirmation process to stop the discharge operation from the battery 15 (i.e., the discharge operation from the battery 15 to the power storage device breaker 5a) by the power conversion circuit unit 13 of the power controller 12. For example, if the maximum absolute value of the discharge current from the battery 15 to each of the voltage lines constituting the power line 2 is equal to or greater than the threshold current for short-circuit detection, it can be determined that there is a short circuit in the circuit. Also, if the absolute value of the sum of the discharge currents to each of the voltage lines is equal to or greater than the threshold current for leakage detection (i.e., if the absolute value of the sum of the instantaneous values ​​of the positive and negative signed discharge currents to each voltage line is equal to or greater than the threshold current for leakage detection), it can be determined that there is a leakage current.

[0061] In this embodiment, in step #23, the control unit 16 executes a power supply operation instruction process and then determines whether or not a power supply abnormality has occurred, in which the above abnormal current condition is met. If a power supply abnormality occurs, the control unit 16 proceeds to step #24 and stops the power supply from the storage battery 15, and in step #25, the control unit 16 outputs information to the user from the information output unit 20 indicating that there is an abnormality. In other words, the control unit 16 performs an abnormality confirmation process and outputs information from the information output unit 20 to make the user aware that there is an abnormality in the discharge current. In response, the control unit 16 terminates this flowchart if no power supply abnormality occurs.

[0062] Furthermore, even when the abnormality check process is not being performed, the control unit 16 will stop the discharge operation from the battery 15 to the power controller 12's power conversion circuit unit 13 if the maximum absolute value of the discharge current from the battery 15 to each voltage line, or the absolute value of the sum of the discharge currents to each voltage line, exceeds the respective threshold current. In this embodiment, the threshold current during the abnormality check process is set to a smaller value than the threshold current during the period when the abnormality check process is not being performed. By setting the threshold current in this way, it is possible to reliably detect a state in which the maximum absolute value of the discharge current from the battery 15 to each voltage line, or the absolute value of the sum of the discharge currents to each voltage line, exceeds the respective threshold current, i.e., a state in which there is a high probability of leakage or short circuit.

[0063] Furthermore, when the likelihood of an earthquake is high, it is preferable to pre-charge the battery 15. Therefore, when the earthquake-related information acquisition unit 17 acquires Nankai Trough Earthquake Provisional Information (Great Earthquake Alert) or Nankai Trough Earthquake Provisional Information (Great Earthquake Warning), the control unit 16 may perform a charge acceleration process in which it instructs the power conversion circuit unit 13 of the power controller 12 to start charging the battery 15 (i.e., charging from the power line 2 to the battery 15) and stops discharging from the battery 15 (i.e., discharging from the battery 15 to the power line 2) until predetermined discharge permission conditions are met. As a result, even if an earthquake actually occurs and power supply from the power system 1 becomes unavailable, sufficient power can be supplied from the battery 15 with its increased charge level. The upper limit charge level during the execution of this charge acceleration process may be set higher than the upper limit charge level when the charge acceleration process is not being executed. In other words, after a Nankai Trough Earthquake Temporary Information (Major Earthquake Alert) or Nankai Trough Earthquake Temporary Information (Major Earthquake Warning) is issued, the charge rate of the battery 15 can be increased compared to when the charging acceleration process is not performed.

[0064] Furthermore, the control unit 16 may determine that the discharge permission condition has been met when the earthquake-related information acquisition unit 17 acquires information indicating that an earthquake of a strength equal to or greater than a second predetermined value has occurred in the area where the energy storage device 10 is installed while the charge acceleration process is being executed, and then execute a discharge acceleration process to permit the power conversion circuit unit 13 of the power controller 12 to discharge from the battery 15. In other words, if an earthquake actually occurs, the amount of energy charged to the battery 15 by the charge acceleration process can be used by the power load 25. Here, the lower limit charge rate during the execution of this discharge acceleration process may be set lower than the lower limit charge rate when the discharge acceleration process is not being executed. In other words, when the amount of energy charged to the battery 15 by the charge acceleration process is used by the power load 25 after an earthquake actually occurs, more energy can be used than when the discharge acceleration process is not performed.

[0065] The control unit 16 then terminates the charging acceleration process when the earthquake-related information acquisition unit 17 receives Nankai Trough earthquake temporary information (investigation completed), or when a set period has elapsed since the earthquake-related information acquisition unit 17 received Nankai Trough earthquake temporary information (investigation completed).

[0066] As described above, if the control unit 16 of the energy storage device 10 determines that an earthquake of a strength exceeding a predetermined value has occurred or is likely to occur in the area where the energy storage device 10 is installed, it executes a charge / discharge stop process that instructs the power conversion circuit unit 13 of the power controller 12 to stop the discharge operation from the battery 15 and the charging operation to the battery 15. In addition, the control unit 16 executes the above charge / discharge stop process, a tripping operation instruction process that instructs the user to open the main breaker 4, the energy storage device breaker 5a, and the load breakers 5b and 5c, and to turn off the power switch 25a on the power load 25 from the information output unit 20, and if predetermined discharge start conditions are met, including the condition that the input reception unit 21 has received an operation input from the user, it executes a discharge start process that instructs the power conversion circuit unit 13 of the power controller 12 to start the discharge operation from the battery 15. In other words, the discharge operation from the battery 15 will not start unless the discharge start condition, which includes the condition that the input receiving unit 21 receives an operation input from the user, is met. This means that power supply from the battery 15 to the power load 25 will not start unconditionally as in the conventional system. Therefore, even if there is damage to the parts electrically connected to the battery 15, it is more likely that the user can prevent leakage or short circuits caused by the battery 15 conducting electricity at the damaged parts. For example, if there is damage that the user can confirm, the user can prevent the discharge start condition from being met and thus prevent power supply from the battery 15 to the power load 25 from starting.

[0067] Furthermore, the control unit 16 opens the main breaker 4, the energy storage device breaker 5a, and the load breakers 5b and 5c, and turns off the power switch 25a on the power load 25, thereby initiating the discharge operation from the battery 15 in a state where power is normally not supplied from the battery 15 to the power load 25. Then, before or after executing the power supply operation instruction process that outputs information from the information output unit 20 to the user to prompt them to close the energy storage device breaker 5a and the load breakers 5b and 5c while the main breaker 4 is open and the power switch 25a of the power load 25 is off, if the control unit 16 determines that an abnormal current condition is met, where the maximum absolute value of the discharge current from the battery 15 to each of the voltage lines constituting the power line 2, or the absolute value of the sum of the discharge currents to each of the voltage lines, continuously exceeds the respective threshold current, it executes an abnormality confirmation process that causes the power conversion circuit unit 13 of the power controller 12 to stop the discharge operation from the battery 15. In other words, the control unit 16 performs an abnormality check process if the discharge current is at a level that can be considered to be due to a leakage current or short circuit. Therefore, it is possible to provide a power storage system that can continue to supply power to facilities equipped with the battery 15 as much as possible even after an earthquake, and that can prevent leakage currents and short circuits as much as possible even if electrical equipment is damaged by the earthquake.

[0068] <Another Embodiment> In the above embodiment, the configuration of the energy storage system is specifically described in Figure 1, but this configuration can be changed as appropriate. Similarly, the processing performed in the energy storage device 10 is specifically explained in Figure 2, but the content of this process can be changed as appropriate. For example, the order of each step shown in Figure 2 can be changed as appropriate, and it is possible to omit any of the steps or add other steps.

[0069] In the above embodiment, the control unit 16 refers to the information acquired by the earthquake-related information acquisition unit 17 and determines that an earthquake of a strength of a first predetermined value or greater has occurred or is likely to occur in the area where the energy storage device 10 is installed, initiating the flowchart in Figure 2. However, the content of this can be changed. For example, the control unit 16 may refer to the information acquired by the earthquake-related information acquisition unit 17 and determine that an earthquake of a strength of a first predetermined value or greater has occurred or is likely to occur in the area where the energy storage device 10 is installed, and also acquires information from the power outage information acquisition unit 18 indicating an abnormal state in which power supply from power system 1 to power line 2 is not being performed normally (i.e., voltage information indicating that a power outage has occurred in power system 1), initiating the flowchart in Figure 2 (i.e., executing the charge / discharge stop process and the cutoff operation instruction process). In that case, when an abnormal state actually occurs in which power supply from power system 1 to power line 2 is not being performed normally, i.e., when a power outage occurs, the charge / discharge stop process and the cutoff operation instruction process described above can be executed.

[0070] In the above embodiment, when the control unit 16 determines in step #23 whether or not a power supply abnormality has occurred in which the abnormal current condition is met, it may measure the discharge current multiple times. For example, in the abnormality confirmation process, the control unit 16 may measure the discharge current from the battery 15 to the power line 2 a predetermined number of times (multiple times) after the power conversion circuit unit 13 of the power controller 12 has started the discharge operation from the battery 15 (i.e., while the battery 15 is being discharged), with a period in between during which the power conversion circuit unit 13 of the power controller 12 is not allowed to discharge from the battery 15. Even after measuring the discharge current a predetermined number of times, the control unit 16 may determine that the abnormal current condition is met if the maximum value of the absolute value of the discharge current to each voltage line or the absolute value of the sum of the discharge currents to each voltage line is equal to or greater than the respective threshold current. This assumes that when a capacitor-input type power load 25 is connected to the power supply from the battery 15, a large current may flow temporarily immediately after the battery 15 discharges, even if a short circuit has not occurred, and that such a large current will no longer flow after charge has accumulated in the capacitor. In other words, by measuring the discharge current multiple times as described above, it is possible to distinguish between the phenomenon of a large current flowing temporarily in the capacitor-input type power load 25 and a short circuit that causes a large current to flow continuously.

[0071] In the above embodiment, the content of the discharge start condition can be changed as appropriate. For example, the control unit 16 may determine that the discharge start condition has been met when the input receiving unit 21 receives an operation input from the user indicating that the user has opened the main breaker 4, the energy storage device breaker 5a, and the load breakers 5b and 5c in response to the tripping operation instruction process, and has turned off the power switch 25a on the power load 25. Alternatively, the control unit 16 may determine that the discharge start condition has been met when the input receiving unit 21 receives an operation input from the user indicating that the user has opened the main breaker 4, the energy storage device breaker 5a, and the load breakers 5b and 5c in response to the tripping operation instruction process, and has turned off the power switch 25a on the power load 25, and also receives an operation input from the user regarding identification information assigned to the user of the energy storage device 10.

[0072] In the above embodiment, the numerical values ​​such as the first predetermined value and the second predetermined value used as the threshold value for earthquake intensity can be set as appropriate.

[0073] In the above embodiment, a switch 28 may be provided to switch between a state in which the energy storage device 10 is connected to the energy storage device breaker 5a and a state in which the energy storage device 10 is connected to a dedicated circuit 26 that is electrically isolated from the power line 2. Figure 3 is a diagram showing the configuration of an energy storage system in another embodiment. As shown in the figure, the switch 28 is provided between the interconnection protection relay 11 of the energy storage device 10 and the energy storage device breaker 5a. In Figure 3, the switch 28 is depicted inside the distribution board 3, but the switch 28 may be provided inside the energy storage device 10. Then, the control unit 16 of the energy storage device 10 refers to the information acquired by the earthquake-related information acquisition unit 17 and determines that an earthquake of a strength equal to or greater than a first predetermined value has occurred or is likely to occur in the area where the energy storage device 10 is installed, and if the power outage information acquisition unit 18 has acquired information indicating an abnormal state, it switches the switch 28 to a state where contact a and contact c are connected (the state shown in Figure 3). Otherwise, it switches the switch 28 to a state where contact a and contact b are connected. Therefore, when the switch 28 is switched to the state shown in Figure 3, the range in which power can be supplied from the energy storage device 10 is limited to only the power load 27 with a power switch 27a connected to the dedicated circuit 26, and power is not supplied from the energy storage device 10 to the power line 2 and the locations electrically connected to it. Therefore, in the case of a power storage system like the one shown in Figure 3, the above-mentioned tripping operation instruction processing (i.e., the process of outputting information from the information output unit 20 to the user to prompt the user to open the main breaker 4 and the load breakers 5b and 5c) becomes unnecessary, and the number of points that the user needs to inspect, as explained in steps #18 and #19 above, is also reduced.

[0074] The configurations disclosed in the above embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. Furthermore, the embodiments disclosed herein are illustrative, and the embodiments of the present invention are not limited thereto and can be modified as appropriate without departing from the purpose of the present invention. [Industrial applicability]

[0075] This invention can be used in an energy storage system that can continue to supply power to facilities equipped with batteries as much as possible even after an earthquake, and can prevent accidents caused by electrical leakage or short circuits as much as possible, even if electrical equipment is damaged by the earthquake. [Explanation of Symbols]

[0076] 1: Power system 2: Power lines 4: Main circuit breaker 5: Circuit breaker 5a: Circuit breaker for energy storage device 5b: Load breaker 5c: Load breaker 10: Energy storage device 12: Power Controller 15: Storage battery 16: Control Unit 17: Earthquake-related information acquisition department 18: Power Outage Information Acquisition Unit 20: Information output unit 21: Input Reception Section 25: Power load

Claims

1. A power storage system comprising a power storage device connected to a power line connected to a power grid, The energy storage device comprises a battery, a power controller that controls the discharge operation from the battery and the charging operation to the battery, and a control unit that controls the operation of the power controller. A circuit breaker for the energy storage device that connects the energy storage device to the power line, A load breaker that connects a power load to the power line, A main circuit breaker located upstream of the aforementioned energy storage device breaker and installed on the aforementioned power line, An information output unit that outputs information to the user, The earthquake-related information acquisition unit acquires information related to earthquakes, The system includes an input receiving unit that receives operation input from the user, The control unit, referring to the information acquired by the earthquake-related information acquisition unit, determines that an earthquake of a strength equal to or greater than a first predetermined value has occurred or is likely to occur in the area where the energy storage device is installed. The system performs a charge / discharge stop process that causes the power controller to stop the discharge operation from the battery and the charging operation to the battery, and a tripping operation instruction process that causes the main circuit breaker, the circuit breaker for the energy storage device, and the circuit breaker for the load to be opened, and outputs information from the information output unit to the user to prompt them to turn off the power switch on the power load. When predetermined discharge start conditions are met, including the execution of the charge / discharge stop process and the cutoff operation instruction process and the acceptance of the input unit receiving an operation input from the user, a discharge start process is executed to cause the power controller to start the discharge operation from the storage battery. After performing the discharge start process, the power supply operation instruction process is performed, which outputs information from the information output unit to the user to prompt them to close the circuit breaker for the energy storage device and the circuit breaker for the load. A power storage system that, before or after executing the power supply operation instruction process, determines that an abnormal current condition is met in which the maximum absolute value of the discharge current from the battery to each of the voltage lines constituting the power line, or the absolute value of the sum of the discharge currents to each of the voltage lines, continuously exceeds the respective threshold current, and executes an abnormality confirmation process to stop the discharge operation from the battery to the power controller.

2. The system includes a power outage information acquisition unit that acquires information indicating whether or not there is an abnormal condition in which power is not being supplied normally from the power system to the power line, The control unit, The energy storage system according to claim 1, which, by referring to the information acquired by the earthquake-related information acquisition unit, determines that an earthquake of a strength equal to or greater than the first predetermined value has occurred or is likely to occur in the area where the energy storage device is installed, and when the power outage information acquisition unit acquires information indicating that the abnormal state is present, executes the charge / discharge stop process and the cutoff operation instruction process.

3. The energy storage system according to claim 1 or 2, wherein the control unit, in the abnormality confirmation process, measures the discharge current from the storage battery a predetermined number of times after the power controller has started the discharge operation from the storage battery, with a period in between during which the power controller is not allowed to perform the discharge operation from the storage battery, and even after measuring the discharge current a predetermined number of times, determines that the abnormal current condition is met if the maximum value of the absolute value of the discharge current to each of the voltage lines or the absolute value of the sum of the discharge currents to each of the voltage lines is equal to or greater than the respective threshold current.

4. The energy storage system according to claim 1 or 2, wherein the control unit performs the abnormality confirmation process and outputs information from the information output unit to the user to make the user aware that there is an abnormality in the discharge current.

5. Even while the abnormality check process is not being performed, if the maximum absolute value of the discharge current from the battery to each of the voltage lines, or the absolute value of the sum of the discharge currents to each of the voltage lines, is greater than or equal to the respective threshold current, the control unit will instruct the power controller to stop the discharge operation from the battery. The energy storage system according to claim 1 or 2, wherein the threshold current during the abnormality check process is set to a value smaller than the threshold current during the abnormality check process is not being performed.

6. The energy storage system according to claim 1 or 2, wherein the control unit determines that an earthquake of strength equal to or greater than the first predetermined value has occurred or is likely to occur in the area where the energy storage device is installed, when the earthquake-related information acquisition unit has acquired information of an emergency earthquake warning targeting the area where the energy storage device is installed.

7. The energy storage system according to claim 1 or 2, wherein the control unit determines that an earthquake of a strength equal to or greater than the first predetermined value has occurred or will occur in the area where the energy storage device is installed, when the earthquake-related information acquisition unit has acquired information regarding a tsunami warning or tsunami advisory for the area where the energy storage device is installed.

8. The energy storage system according to claim 1 or 2, wherein the control unit determines that an earthquake of a strength equal to or greater than the first predetermined value has occurred or will occur in the area where the energy storage device is installed if it is unable to communicate information with other devices via the Internet.

9. The energy storage system according to claim 1 or 2, wherein the control unit, when it obtains Nankai Trough Earthquake Temporary Information (Mega-earthquake Warning) or Nankai Trough Earthquake Temporary Information (Mega-earthquake Caution), causes the power controller to start charging the storage battery, and executes a charging acceleration process which causes the power controller to stop discharging from the storage battery until predetermined discharge permission conditions are met.

10. The control unit causes the power controller to perform a charging operation to the battery so that the battery's charge level does not exceed a predetermined upper limit charge level. The energy storage system according to claim 9, wherein the upper limit charge rate during the charging acceleration process is set to be higher than the upper limit charge rate during the charging acceleration process is not being performed.

11. The energy storage system according to claim 9, wherein the control unit determines that the discharge permission condition has been met when the earthquake-related information acquisition unit acquires information indicating that an earthquake of a strength of a second predetermined value or greater has occurred in the area where the energy storage device is installed while the charge acceleration process is being performed, and then executes a discharge acceleration process to permit the power controller to discharge from the battery.

12. The control unit causes the power controller to perform a discharge operation from the battery so that the charge level of the battery does not fall below a predetermined lower limit charge level. The energy storage system according to claim 11, wherein the lower limit charge rate during the discharge acceleration treatment is set lower than the lower limit charge rate during the period when the discharge acceleration treatment is not being performed.

13. The energy storage system according to claim 11, wherein the control unit terminates the charging acceleration process when the earthquake-related information acquisition unit receives Nankai Trough earthquake temporary information (investigation completed), or after a set period has elapsed since the earthquake-related information acquisition unit received Nankai Trough earthquake temporary information (investigation completed).

14. The energy storage system according to claim 1 or 2, wherein the control unit determines that the discharge start condition has been met when the input receiving unit receives an operation input from the user indicating that the user has opened the main circuit breaker, the energy storage device circuit breaker, and the load circuit breaker in response to the tripping operation instruction process, and has turned off the power switch on the power load.

15. The energy storage system according to claim 14, wherein the control unit determines that the discharge start condition has been met when the input receiving unit receives an operation input from the user indicating that the user has opened the main circuit breaker, the energy storage device circuit breaker and the load circuit breaker in response to the tripping operation instruction process, and has turned off the power switch on the power load, and the input receiving unit receives an operation input from the user regarding identification information assigned to the user of the energy storage device.

16. The energy storage system according to claim 1 or 2, wherein the control unit outputs from the information output unit information about the operations that the user needs to perform in order for the discharge start process to be executed, before or after the cutoff operation instruction process is executed.

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