Power system and control method

Abstract

This power system comprises: a power storage device to be installed in a facility connected to a power grid, and a control unit for controlling the power storage device. The control unit: determines whether or not a first condition, which the power storage residual amount of the power storage device has to satisfy, is set as a condition for switching the state of the power storage device from a linkage state in which the facility is linked to the power grid to an independent state in which the facility is disconnected from the power grid; and executes, when the power storage device is a specific power storage device in which the first condition is provided, a specific control for controlling the specific power storage device so as to satisfy the first condition by the power storage residual amount of the specific power storage device.

Description

Technical Field

[0001] The present disclosure relates to a power system and a control method.

Background Art

[0002] In recent years, in order to maintain the power supply-demand balance of the power system, a technique of using a power storage device as a distributed power source (for example, a VPP (Virtual Power Plant)) is known (for example, Patent Documents 1 and 2). It is conceivable to use a power storage device as a power source used in a VPP or the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

[0004] A first feature is a power system including a power storage device installed in a facility connected to the power system and a control unit that controls the power storage device. The control unit determines whether a first condition to be satisfied by the remaining charge amount of the power storage device is defined as a condition for the power storage device to switch from a connected state in which the facility is connected to the power system to an independent state in which the facility is disconnected from the power system. When the power storage device is a specific power storage device for which the first condition is defined, specific control is executed to control the specific power storage device so that the remaining charge amount of the specific power storage device satisfies the first condition.

[0005] The second feature is a control method, which includes step A of controlling a power storage device installed in a facility connected to a power system. Step A includes: a step of determining whether a first condition to be satisfied by the remaining charge amount of the power storage device is defined as a condition for the power storage device to switch from a connected state in which the facility is connected to the power system to an islanded state in which the facility is disconnected from the power system; and a step of executing specific control for controlling the specific power storage device so that the remaining charge amount of the specific power storage device satisfies the first condition when the power storage device is the specific power storage device for which the first condition is defined. This is the gist of the invention.

Advantages of the Invention

[0006] According to the present invention, it is possible to provide a power system and a control method that can appropriately switch the operation of a power storage device from grid-connected operation to islanded operation.

Brief Description of the Drawings

[0007]

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Best Mode for Carrying Out the Invention

[0008] In the following, embodiments will be described with reference to the drawings. In the description of the following drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic.

[0009] [Embodiment] (Power Management System) In the following, the power management system according to the embodiment will be described. The power management system may simply be referred to as a power system.

[0010] As shown in FIG. 1, the power management system 1 has a facility 100. The power management system 1 may include a power management server 200.

[0011] Here, the facility 100 and the power management server 200 are configured to be communicable via a network 11. The network 11 may include the Internet, may include a dedicated line such as a VPN (Virtual Private Network), or may include a mobile communication network.

[0012] The facility 100 is connected to a power system 12, and power may be supplied from the power system 12 to the facility 100, or the facility 100 may supply power to the power system 12. The power from the power system 12 to the facility 100 may be referred to as tidal power, purchased power, or demand power. The power from the facility 100 to the power system 12 may be referred to as reverse tidal power or sold power. In FIG. 1, facilities 100A to 100C are illustrated as the facility 100.

[0013] Although not particularly limited, the power system 12 may be a small-scale power system (microgrid) in which the power consumption of load devices is covered by power supplied from distributed power sources in a specific area. The power system 12 may be a commercial power system provided by an operator such as an electric power company. The microgrid may be connected to a commercial power system or may not be connected to a commercial power system.

[0014] Although not particularly limited, the facility 100 may be a facility such as a house, a facility such as a store, or a facility such as an office. The facility 100 may be an apartment building including two or more houses. The facility 100 may be a complex facility including at least two or more of houses, stores, and offices. Details of the facility 100 will be described later (see FIG. 2).

[0015] The power management server 200 may be managed by an operator such as a regional electric power company. The regional electric power company may be an electric power company operated by a local government or the like. The power management server 200 may be referred to as an AEMS (Area Energy Management System). The power management server 200 is a server managed by an operator such as a power generation business operator, a power transmission and distribution business operator, a retail business operator, or a resource aggregator. The resource aggregator may be a power business operator that adjusts the power supply and demand balance of the power system 12 in a VPP (Virtual Power Plant). The adjustment of the power supply and demand balance may include a transaction (hereinafter, a negative watt transaction) that exchanges the reduced power of the demand power (tidal current power) of the facility 100 for value. The adjustment of the power supply and demand balance may include a transaction that exchanges the increased power of the reverse tidal current power for value. The resource aggregator may be a power business operator that provides reverse tidal current power to a power generation business operator, a power transmission and distribution business operator, a retail business operator, etc. in a VPP.

[0016] (Facility) Hereinafter, the facility according to the embodiment will be described. As shown in FIG. 2, the facility 100 includes a solar cell device 110, a power storage device 120, a fuel cell device 130, a power storage device 140, a load device 150, and an EMS (Energy Management System) 160. The facility 100 may include a measurement device 190.

[0017] The solar cell device 110 is a distributed power source that generates electricity in response to light such as sunlight. For example, the solar cell device 110 is composed of a PCS (Power Conditioning System) and a solar panel. In an embodiment, the solar cell device 110 may be an example of a power generation device installed in the facility 100. Here, installation may mean that the solar cell device 110 and the power grid 12 are connected.

[0018] The energy storage device 120 is a distributed power source that charges and discharges electricity. For example, the energy storage device 120 is composed of a PCS and energy storage cells. In an embodiment, the energy storage device 120 may be an example of an energy storage device installed in the facility 100. The energy storage device 120 may be referred to as a stationary energy storage device 120 in order to distinguish it from the energy storage device 140. Here, installation may mean that the energy storage device 120 and the power grid 12 are connected.

[0019] The fuel cell device 130 is a distributed power source that generates electricity using fuel. For example, the fuel cell device 130 is composed of a PCS and fuel cells.

[0020] For example, the fuel cell device 130 may be a solid oxide fuel cell (SOFC; Solid Oxide Fuel Cell), a polymer electrolyte fuel cell (PEFC; Polymer Electrolyte Fuel Cell), a phosphoric acid fuel cell (PAFC; Phosphoric Acid Fuel Cell), or a molten carbonate fuel cell (MCFC; Molten Carbonate Fuel Cell).

[0021] In an embodiment, the fuel cell device 130 may be an example of a power generation device installed in the facility 100. Here, installation may mean that the fuel cell device 130 and the power grid 12 are connected.

[0022] The power storage device 140 is a distributed power source that charges and discharges electric power. For example, the power storage device 140 is composed of power storage cells and is mounted on an electric vehicle (EV). The power storage device 140 may be connected to a charging device installed in the facility 100. The charging device may include a PCS. The power storage device 140 may be referred to as an in-vehicle power storage device 140 in order to distinguish it from the power storage device 120.

[0023] In an embodiment, the power storage device 140 may be an example of a specific power storage device in which a first condition is defined for the remaining charge amount of the power storage device 140 to satisfy as a condition for the power storage device 140 to switch from the connected state to the self-sufficient state. The connected state is a state in which the facility 100 is connected to the power grid 12. The self-sufficient state is a state in which the facility 100 is disconnected from the power grid 12. For example, the self-sufficient state may occur due to a power outage in the power grid 12. The power outage may include a planned power outage executed according to a predetermined plan, and may also include an unplanned power outage (e.g., a total power outage, etc.) caused by natural disasters such as fires, lightning, heavy rain, and strong winds. The operation of the power storage device 140 in the connected state may be referred to as connected operation. The operation of the power storage device 140 in the self-sufficient state may be referred to as self-sufficient operation.

[0024] The first condition may include a condition that the remaining charge amount of the power storage device 140 is less than or equal to the upper limit constraint remaining amount. The upper limit constraint remaining amount is a remaining amount smaller than the total capacity of the power storage device 140. That is, when the first condition is satisfied, a chargeable capacity (chargeable capacity) of the power storage device 140 is ensured.

[0025] Although not particularly limited, the above-described power storage device 120 may be an example of a normal power storage device in which the first condition is not defined, unlike the power storage device 140.

[0026] The first condition may be defined based on whether the configuration regarding the distributed power source other than the power storage device 140 installed in the facility 100 satisfies the second condition. That is, the first condition may be a condition applied in a case where the second condition is satisfied, and may not be applied in a case where the second condition is not satisfied.

[0027] The second condition may be any condition that the configuration regarding the distributed power sources other than the power storage device 140 installed in the facility 100 should satisfy. For example, the second condition may be a condition that a distributed power source (hereinafter referred to as a specific distributed power source) capable of supplying power to the power storage device 140 in an independent state is installed in the facility 100. The specific distributed power source may be the solar cell device 110. The specific distributed power source may include the fuel cell device 130 or may not include the fuel cell device 130. The specific distributed power source may include the power storage device 120 or may not include the power storage device 120. Note that the configuration regarding the distributed power sources may be considered as a configuration such as whether the specific distributed power source is installed in the facility 100 and the type of the specific distributed power source.

[0028] The load device 150 is a device that consumes power. For example, the load device 150 may include an air conditioner that adjusts the temperature of a predetermined space, or may include a lighting device that adjusts the illuminance of a predetermined space. The air conditioner and the lighting device are an example of a predetermined device that adjusts the environment of a predetermined space. The air conditioner and the lighting device may be considered as devices that are affected by the operation of the power storage device 140. The load device 150 may include video devices, audio devices, refrigerators, washing machines, personal computers, and the like.

[0029] The EMS 160 manages the power regarding the facility 100. The EMS 160 may control the solar cell device 110, the power storage device 120, the fuel cell device 130, the power storage device 140, and the load device 150. In the embodiment, the EMS 160 is exemplified as a device that receives a control command from the power management server 200, but such a device may be referred to as a Gateway or simply as a control unit. The EMS 160 may be referred to as a LEMS (Local EMS) or a HEMS (Home EMS) in order to distinguish it from the power management server 200. Details of the EMS 160 will be described later (see FIG. 4).

[0030] The measuring device 190 measures the power flow from the power system 12 to the facility 100. The measuring device 190 may measure the reverse power flow from the facility 100 to the power system 12. For example, the measuring device 190 may be a Smart Meter belonging to an electric power company. The measuring device 190 may transmit an information element indicating the measurement result (integrated value of power flow or reverse power flow) in the first interval (e.g., 30 minutes) to the EMS 160 for each first interval. The measuring device 190 may transmit an information element indicating the measurement result in the second interval (e.g., 1 minute) shorter than the first interval to the EMS 160.

[0031] (Power management server) Hereinafter, the power management server will be described. As shown in FIG. 3, the power management server 200 includes a management unit 210, a communication unit 220, and a control unit 230. Note that the power management server 200 can communicate with the facility 100 via the network 11 and may be considered as a server operating on the cloud.

[0032] The management unit 210 is composed of a storage medium such as an SSD (Solid State Drive), an HDD (Hard Disk Drive), and a non-volatile semiconductor memory, and manages information regarding the facility 100. For example, the information regarding the facility 100 includes the type of distributed power sources (solar cell device 110, power storage device 120, fuel cell device 130, or power storage device 140) provided in the facility 100, the specifications of the distributed power sources provided in the facility 100, and the like. The specifications may include the rated power generation power of the solar cell device 110, the rated charge / discharge power of the power storage device 120, the rated output power of the fuel cell device 130, and the rated charge / discharge power of the power storage device 140. The specifications may include the rated capacity of the power storage device 120, the maximum charge / discharge power, and the like. The specifications may include the rated capacity of the power storage device 140, the maximum charge / discharge power, and the like.

[0033] The communication unit 220 is composed of a communication module and communicates with the EMS 160 via the network 11. The communication module may be a wireless communication module compliant with standards such as IEEE802.11a / b / g / n / ac / ax, ZigBee, Wi-SUN, LTE, 5G, 6G, etc., or may be a wired communication module compliant with standards such as IEEE802.3.

[0034] For example, the communication unit 220 may transmit a control command to a distributed power source (solar cell device 110, energy storage device 120, fuel cell device 130, or energy storage device 140) provided in the facility 100.

[0035] The control unit 230 may include at least one processor. The at least one processor may be composed of a single integrated circuit (IC) or may be composed of a plurality of circuits (such as integrated circuits and / or discrete circuits) communicatively connected.

[0036] In an embodiment, the control unit 230 constitutes a control unit that controls at least the energy storage device 140. The control unit 230 may control other distributed power sources (solar cell device 110, energy storage device 120, or fuel cell device 130) installed in the facility 100.

[0037] When switching from the grid-connected state to the self-sufficient state, the control unit 230 determines whether a first condition that the remaining charge of the energy storage device should satisfy is defined. When the energy storage device is a specific energy storage device for which the first condition is defined, the control unit 230 executes specific control to control the specific energy storage device so that the remaining charge of the specific energy storage device satisfies the first condition.

[0038] Specifically, when the control unit 230 controls the energy storage device 140, which is an example of a specific energy storage device, the control unit 230 executes specific control to control the energy storage device 140 so that the remaining charge of the energy storage device 140 satisfies the first condition. In other words, the control unit 230 controls the charging or discharging of the energy storage device 140 so that the remaining charge of the energy storage device 140 does not exceed the upper limit remaining amount.

[0039] On the other hand, when the control unit 230 controls the power storage device 120 which is an example of a normal power storage device, the control unit 230 may control the power storage device 120 regardless of whether the remaining power storage amount of the power storage device 120 satisfies the first condition. In other words, the control unit 230 may allow charging or discharging of the power storage device 120 whose remaining power storage amount exceeds the upper limit constraint remaining amount.

[0040] Furthermore, when the configuration related to the distributed power source satisfies the second condition and the first condition is defined, the control unit 230 may execute specific control to control a specific power storage device so that the remaining power storage amount of the specific power storage device satisfies the first condition.

[0041] Specifically, when the control unit 230 controls the power storage device 140 which is an example of a specific power storage device, if the configuration related to the distributed power source satisfies the second condition, the control unit 230 may execute specific control to control the power storage device 140 so that the remaining power storage amount of the power storage device 140 satisfies the first condition. In other words, when the second condition is satisfied, the control unit 230 controls charging or discharging of the power storage device 140 so that the remaining power storage amount of the power storage device 140 does not exceed the upper limit constraint remaining amount.

[0042] On the other hand, when the control unit 230 controls the power storage device 140 which is an example of a specific power storage device, if the configuration related to the distributed power source does not satisfy the second condition, the control unit 230 may control the power storage device 140 regardless of whether the remaining power storage amount of the power storage device 140 satisfies the first condition. In other words, when the second condition is not satisfied, the control unit 230 may allow charging or discharging of the power storage device 140 whose remaining power storage amount exceeds the upper limit constraint remaining amount.

[0043] The specific control may be control to control a specific power storage device before the switching timing so that the remaining power storage amount of the specific power storage device satisfies the first condition at the timing of switching from the connected state to the self - supporting state (hereinafter, the switching timing).

[0044] Here, the control unit 230 may execute specific control triggered by obtaining information indicating the plan or possibility of switching from the linked state to the self - supporting state (for example, an alarm described later) before the switching timing. Alternatively, the control unit 230 may execute specific control triggered by obtaining information specifying the first condition (constraint information described later) before the switching timing. Alternatively, the control unit 230 may execute specific control triggered by other conditions (for example, the power consumption of the load device 150 exceeding a threshold value, etc.) before the switching timing. Note that the switching timing may be considered as a term indicating an instantaneous point when switching from the linked state to the self - supporting state.

[0045] Specifically, on the premise that the first condition is satisfied by the switching timing, the control unit 230 may allow charging or discharging of the power storage device 140 whose remaining power storage amount exceeds the upper limit constraint remaining amount before the switching timing.

[0046] (EMS) Hereinafter, the EMS according to the embodiment will be described. As shown in FIG. 4, the EMS 160 includes a first communication unit 161, a second communication unit 162, and a control unit 163.

[0047] The first communication unit 161 is composed of a communication module. The communication module may be a wireless communication module compliant with standards such as IEEE802.11a / b / g / n / ac / ax, ZigBee, Wi - SUN, LTE, 5G, 6G, etc., or may be a wired communication module compliant with standards such as IEEE802.3.

[0048] For example, the first communication unit 161 communicates with the power management server 200 via the network 11. As described above, the first communication unit 161 communicates according to the first protocol. For example, the first communication unit 161 receives a first message from the power management server 200 according to the first protocol. The first communication unit 161 transmits a first message response to the power management server 200 according to the first protocol.

[0049] The second communication unit 162 is composed of a communication module. The communication module may be a wireless communication module compliant with standards such as IEEE802.11a / b / g / n / ac / ax, ZigBee, Wi-SUN, LTE, 5G, 6G, etc., or may be a wired communication module compliant with standards such as IEEE802.3.

[0050] For example, the second communication unit 162 communicates with devices (solar cell device 110, power storage device 120, fuel cell device 130, or power storage device 140) included in the facility 100. As described above, the second communication unit 162 communicates according to the second protocol. For example, the second communication unit 162 transmits a second message to the distributed power source according to the second protocol. The second communication unit 162 receives a second message response from the distributed power source according to the second protocol. As described above, the second message may be a message including an information element for specifying the operation mode of the power storage device 140.

[0051] The control unit 163 may include at least one processor. The at least one processor may be composed of a single integrated circuit (IC), or may be composed of a plurality of circuits (such as integrated circuits and / or discrete circuits) communicably connected.

[0052] For example, the control unit 163 may control distributed power sources (solar cell device 110, power storage device 120, fuel cell device 130, or power storage device 140) provided in the facility 100 based on control commands received from the power management server 200.

[0053] (Capacity of the power storage device) Hereinafter, the capacity of the power storage device according to the embodiment will be described with reference to FIG. 5. The power storage device may be the power storage device 120 or the power storage device 140. Hereinafter, the power storage device 140 will be exemplified.

[0054] As shown in FIG. 5, the capacity of the power storage device 140 includes the unusable capacity in which the use of the power storage device 140 is restricted from the viewpoint of suppressing deterioration of the power storage device 140 or the like. The threshold TH1 is a threshold for specifying the unusable capacity (upper limit side), and the threshold TH2 is a threshold for specifying the unusable capacity (lower limit side). The capacity of the power storage device 140 may include an emergency capacity (BCP (Business Continuity Plan) capacity) in order to cope with an emergency such as a disaster. The threshold TH3 is a threshold for specifying the BCP capacity.

[0055] In the following, the description will proceed on the assumption that the total capacity of the power storage device 140 is the capacity excluding the unusable capacity. In the normal state other than an emergency, since the BCP capacity is not used, the capacity that can be discharged from the power storage device 140 (dischargeable capacity) may be a value obtained by subtracting the BCP capacity from the power stored in the power storage device 140 (remaining charge amount). The capacity that can be charged to the power storage device 140 (chargeable capacity) is a value obtained by subtracting the remaining charge amount from the total capacity. Note that, for the sake of convenience, the sum of the remaining charge amount and the unusable capacity (lower limit side) is referred to as the storage capacity.

[0056] The remaining charge amount of the power storage device 140 (hereinafter, SOC; State Of Charge) may be determined based on the capacity between TH1 and TH2 (that is, the total capacity of the power storage device 140). Specifically, the SOC of the power storage device 140 is represented by the ratio of the storage capacity of the power storage device 140 to the total capacity of the power storage device 140. The upper limit SOC is specified by the above-described threshold TH1. The lower limit SOC is specified by the threshold TH3.

[0057] In such a case, the method for measuring the SOC may be a method using a curve (hereinafter, SOC-OCV curve) representing the relationship between the SOC and the OCV (Open Circuit Voltage). In such a method, the SOC can be measured by detecting the voltage value at the output terminal of the power storage device 140. However, the method for measuring the SOC is not limited to this, and a method using the integration of the current accompanying charging or discharging of the power storage device 140 may be used.

[0058] Furthermore, the overall capacity may be re-measured by performing regular maintenance on the power storage device 140. Specifically, the re-measurement is performed by discharging the power storage device 140 from a fully charged state to a predetermined discharge state. The predetermined discharge state is a state in which the discharge of the BCP capacity has been performed. However, the discharge is not performed until the unusable capacity (lower limit side) is discharged. When the SOC is measured using the SOC-OCV curve, the voltage values corresponding to the upper limit SOC and the lower limit SOC may be redefined by such maintenance.

[0059] In the embodiment, the overall capacity of the power storage device 140 may be represented by SOC = 100%. In such a case, the upper limit constraint remaining amount may be represented by, for example, SOC = 95%. That is, when specific control is executed so that the remaining charge amount of the power storage device 140 does not exceed the upper limit constraint remaining amount, a chargeable capacity of SOC = 5% or more is ensured.

[0060] (Control Method) Hereinafter, the control method according to the embodiment will be described. Here, the case of controlling the power storage device 140, which is an example of a specific power storage device, will be mainly described.

[0061] As shown in FIG. 6, in step S11, the EMS 160 acquires configuration information. The configuration information is information for determining whether the second condition is satisfied. The configuration information may be manually input to the EMS 160. The configuration information may be collected (received) by the EMS 160 from each device installed in the facility 100. The configuration information includes information on distributed power sources other than the power storage device 140 installed in the facility 100. The configuration information may include information indicating whether a distributed power source other than the power storage device 140 is connected to the upstream side (power grid 12 side) of the power storage device 140 or whether a distributed power source other than the power storage device 140 is connected to the downstream side (opposite side of the power grid 12) of the power storage device 140. The configuration information may include information indicating the equipment capacity of a distributed power source other than the power storage device 140, and may include information indicating the type of a distributed power source other than the power storage device 140. The configuration information may include information on the power storage device 140 installed in the facility 100.

[0062] Here, the configuration information may be considered as the self - standing state configuration information regarding the facility 100. However, when switching from the linked state to the self - standing state, if there is no device that becomes unusable in the self - standing state, the self - standing state configuration information regarding the facility 100 may be the same as the linked state configuration information regarding the facility 100.

[0063] In step S12, the EMS 160 acquires constraint information. The constraint information is information that specifies the above - mentioned first condition. For example, the constraint information includes information that specifies the upper limit remaining amount of the constraint. In the embodiment, the constraint information may be manually input to the EMS 160.

[0064] In step S13, the EMS 160 notifies the power storage device 140 of information regarding whether the first condition is applied to the power storage device 140. The information is specified by the configuration information and the constraint information. Here, the case where the first condition is applied to the power storage device 140 will be continued to be described.

[0065] In step S14, the EMS 160 notifies the power management server 200 of information regarding whether the first condition is applied to the power storage device 140. The information is specified by the configuration information and the constraint information. Here, the case where the first condition is applied to the power storage device 140 will be continued to be described.

[0066] In step S15, the power management server 200 acquires an alarm indicating that there may be a switch from the linked state to the self - standing state. The alarm may be acquired from an external server other than the power management server 200. For example, the alarm may include an alarm indicating that a planned power outage is scheduled. The alarm may be an alarm regarding a natural disaster indicating that an unplanned power outage (e.g., a total power outage, etc.) may occur.

[0067] In step S16, the power management server 200 transmits a control command regarding the power storage device 140 to the EMS 160. Here, the control command is a control command that instructs the charging or discharging of the power storage device 140 so that the remaining charge amount of the power storage device 140 does not exceed the upper limit remaining amount of the constraint.

[0068] In step S17, the EMS16 transmits the control command to the power storage device 140 according to the control command received from the power management server 200.

[0069] Note that steps S16 and S17 are an example of the specific control described above.

[0070] In step S18, the power management server 200 detects a power outage. The power outage is an example of a trigger for switching from the grid-connected state to the self-sustaining state.

[0071] In step S19, the power management server 200 transmits an operation instruction to switch the operation of the power storage device 140 to self-sustaining operation to the EMS160.

[0072] In step S20, the EMS160 transmits an operation instruction to switch the operation of the power storage device 140 to self-sustaining operation to the power storage device 140 according to the operation instruction received from the power management server 200.

[0073] (Function and effect) In the embodiment, when the power management server 200 switches from the grid-connected state to the self-sustaining state, it determines whether a first condition that the remaining power storage amount of the power storage device should satisfy is defined. When the control unit 230 determines that the power storage device is a specific power storage device for which the first condition is defined, the control unit 230 executes specific control to control the specific power storage device so that the remaining power storage amount of the specific power storage device satisfies the first condition. According to such a configuration, the operation of the power storage device that is a specific power storage device (in the embodiment, the power storage device 140) for which the first condition is defined can be appropriately switched from grid-connected operation to self-sustaining operation. In other words, it is possible to avoid a situation where the specific power storage device cannot be used in the self-sustaining state.

[0074] In the embodiment, the first condition may be applied in a case where the configuration regarding distributed power sources other than the power storage device 140 installed in the facility 100 satisfies the second condition. According to such a configuration, specific control for controlling the specific power storage device so that the remaining power storage amount of the specific power storage device satisfies the first condition can be executed only in a case where it is assumed that it is necessary to secure the charging margin of the specific power storage device in the self - supporting state.

[0075] [Modification Example 1] Hereinafter, Modification Example 1 of the embodiment will be described. In the following, the differences from the embodiment will be mainly described.

[0076] In the embodiment, a case where the EMS 160 intervenes is exemplified. In contrast, in Modification Example 1, a case where the EMS 160 does not intervene will be described.

[0077] (Control Method) Hereinafter, the control method according to Modification Example 1 will be described. Here, a case of controlling the power storage device 140, which is an example of the specific power storage device, will be mainly described.

[0078] As shown in FIG. 7, in step S11A, the power management server 200 acquires configuration information. The configuration information may be manually input to the power management server 200. The configuration information may be collected (received) by each device installed in the facility 100 or by the power management server 200. The configuration information includes information on distributed power sources other than the power storage device 140 installed in the facility 100. The configuration information may include information indicating whether the distributed power source other than the power storage device 140 is connected to the upstream side (power grid 12 side) with respect to the power storage device 140 or whether the distributed power source other than the power storage device 140 is connected to the downstream side (opposite side of the power grid 12) with respect to the power storage device 140. The configuration information may include information indicating the equipment capacity of the distributed power source other than the power storage device 140, and may include information indicating the type of the distributed power source other than the power storage device 140. The configuration information may include information on the power storage device 140 installed in the facility 100.

[0079] In step S12A, the power management server 200 acquires constraint information. The constraint information is information that specifies the first condition described above. For example, the constraint information includes information that specifies the upper limit constraint remaining amount. In modification example 1, the constraint information may be manually input to the power management server 200. Here, the description continues with the case where the first condition is applied to the power storage device 140.

[0080] In step S15, the power management server 200 acquires an alarm indicating that there is a possibility of switching from the connected state to the self - supporting state. The alarm may be acquired from an external server other than the power management server 200. For example, the alarm may include an alarm indicating that a planned power outage is scheduled. The alarm may be an alarm regarding a natural disaster indicating that an unplanned power outage (e.g., a total power outage, etc.) may occur.

[0081] In step S16A, the power management server 200 transmits a control command regarding the power storage device 140 to the power storage device 140. Here, the control command is a control command that instructs charging or discharging of the power storage device 140 so that the remaining charge amount of the power storage device 140 does not exceed the upper limit constraint remaining amount.

[0082] Note that step S16A is an example of the specific control described above.

[0083] In step S18, the power management server 200 detects a power outage. The power outage is an example of a trigger for switching from the connected state to the self - supporting state.

[0084] In step S19A, the power management server 200 transmits an operation instruction to switch the operation of the power storage device 140 to self - supporting operation to the power storage device 140.

[0085] [Modification Example 2] Hereinafter, modification example 2 of the embodiment will be described. Hereinafter, the differences from the embodiment will be mainly described.

[0086] In the embodiment, a case where constraint information is manually input to the EMS 160 was exemplified. In contrast, in Modification 2, a case where constraint information is collected (received) from the power storage device 140 will be described.

[0087] (Control Method) Hereinafter, the control method according to Modification 2 will be described. Here, a case of controlling the power storage device 140, which is an example of a specific power storage device, will be mainly described.

[0088] As shown in FIG. 8, in step S31, the power storage device 140 transmits constraint information to the EMS 160. The constraint information is information that specifies the first condition described above. For example, the constraint information includes information that specifies the upper limit remaining amount.

[0089] Here, the configuration information may be known to the EMS 160. Alternatively, the configuration information may be known to the power storage device 140, and the power storage device 140 may transmit the constraint information to the EMS 160 when the second condition is satisfied. Here, the description will continue with a case where the first condition is applied to the power storage device 140.

[0090] In step S32, the power management server 200 acquires an alarm indicating that there is a possibility of switching from the interconnected state to the self - supporting state. The alarm may be acquired from an external server other than the power management server 200. For example, the alarm may include an alarm indicating that a planned power outage is scheduled. The alarm may be an alarm regarding a natural disaster indicating that an unplanned power outage (e.g., a total power outage, etc.) may occur.

[0091] In step S33, the power management server 200 transmits a control command regarding the power storage device 140 to the EMS 160. Here, the control command may be transmitted regardless of whether the first condition is satisfied.

[0092] In step S34, the EMS 160 converts the control command received from the power management server 200. Specifically, the EMS 160 converts the control command received from the power management server 200 so that the remaining charge amount of the power storage device 140 does not exceed the upper limit constraint remaining amount.

[0093] In step S35, the EMS 160 transmits the converted control command to the power storage device 140. Here, the control command is a control command for instructing charging or discharging of the power storage device 140 so that the remaining charge amount of the power storage device 140 does not exceed the upper limit constraint remaining amount.

[0094] Note that steps S34 and S35 are an example of the above-described specific control.

[0095] In step S36, the power management server 200 detects a power outage. The power outage is an example of a trigger for switching from the grid-connected state to the self-sustaining state.

[0096] In step S37, the power management server 200 transmits an operation instruction to switch the operation of the power storage device 140 to self-sustaining operation to the EMS 160.

[0097] In step S38, the EMS 160 transmits an operation instruction to switch the operation of the power storage device 140 to self-sustaining operation to the power storage device 140 according to the operation instruction received from the power management server 200.

[0098] [Modification Example 3] Hereinafter, modification example 3 of the embodiment will be described. Hereinafter, the differences from modification example 2 will be mainly described.

[0099] In modification example 2, a case where the EMS 160 is interposed was exemplified. In contrast, in modification example 3, a case where the EMS 160 is not interposed will be described.

[0100] (Control Method) Hereinafter, the control method according to Modification Example 3 will be described. Here, a case of controlling the power storage device 140, which is an example of a specific power storage device, will be mainly described.

[0101] As shown in FIG. 9, in step S31A, the power storage device 140 transmits constraint information to the power management server 200. The constraint information is information specifying the first condition described above. For example, the constraint information includes information specifying the upper limit remaining amount.

[0102] Here, the configuration information may be known to the power management server 200. Alternatively, the configuration information may be known to the power storage device 140, and the power storage device 140 may transmit the constraint information to the power management server 200 when the second condition is satisfied. Here, the description will continue with the case where the first condition is applied to the power storage device 140.

[0103] In step S32, the power management server 200 acquires an alarm indicating that there is a possibility of switching from the grid-connected state to the off-grid state. The alarm may be acquired from an external server other than the power management server 200. For example, the alarm may include an alarm indicating that a planned power outage is scheduled. The alarm may be an alarm regarding a natural disaster indicating that an unplanned power outage (e.g., a total power outage, etc.) may occur.

[0104] In step S33A, the power management server 200 transmits a control command regarding the power storage device 140 to the power storage device 140. Here, the control command is a control command instructing charging or discharging of the power storage device 140 so that the remaining charge amount of the power storage device 140 does not exceed the upper limit remaining amount.

[0105] Note that step S33A is an example of the specific control described above.

[0106] In step S36, the power management server 200 detects a power outage. The power outage is an example of a trigger for switching from the grid-connected state to the off-grid state.

[0107] In step S37A, the power management server 200 transmits an operation instruction to switch the operation of the power storage device 140 to independent operation to the power storage device 140.

[0108] [Modification Example 4] In the following, modification example 4 of the embodiment will be described. In the following, the differences from the embodiment will be mainly described.

[0109] In modification example 4, the power management server 200 executes a reading control to read the remaining charge amount of a specific power storage device as a remaining charge amount different from the actual remaining charge amount during the period in which the specific control is being executed. Specifically, the reading control may be a control that reads the remaining charge amount of the power storage device 140 assuming that the upper limit constraint remaining amount is the total capacity.

[0110] For example, as shown in FIG. 10, consider a case where the total capacity (upper limit SOC in FIG. 10) is 100% and the upper limit constraint remaining amount (constraint SOC in FIG. 10) is 95%. The control SOC is the SOC used in the control of the power storage device 140 and is the SOC before the reading control is executed. The management SOC is the SOC notified to the user and is the SOC after the reading control is executed.

[0111] Here, during the period in which the specific control is being executed, the remaining charge amount of the power storage device 140 is controlled so as not to exceed the upper limit constraint remaining amount. However, as a user, there is a sense of discomfort when the state where the power storage device 140 does not become fully charged continues. That is, even though the user has confirmed that the SOC is instructed to reach 100%, a sense of discomfort occurs that the SOC (management SOC) notified to the user will never reach 100%. Therefore, in modification example 4, the above-described reading control is executed.

[0112] For example, the power management server 200 may multiply the coefficient obtained by dividing the total capacity by the upper limit constraint remaining amount (for example, 100 / 95) by the actual SOC (SOC in control). The read replacement control may be executed when the SOC is equal to or higher than a certain value (for example, 50%). The read replacement control may be executed when the SOC reaches the constraint SOC.

[0113] [Modification Example 5] Hereinafter, Modification Example 5 of the embodiment will be described. Hereinafter, the differences from the embodiment will be mainly described.

[0114] As described above, the specific power storage device is a power storage device defined by the first condition. In Modification Example 5, the variations of the specific power storage device will be described.

[0115] First, when the first condition is satisfied, the specific power storage device switches from the linked state to the self - standing state and then accepts the control command transmitted from the EMS 160 or the power management server 200. When the first condition is not satisfied, the specific power storage device may not switch from the linked state to the self - standing state and stop accepting the control command transmitted from the EMS 160 or the power management server 200.

[0116] That is, the specific power storage device has a function of autonomously determining whether the first condition is satisfied. When the first condition is not satisfied, the specific power storage device may not switch from the linked state to the self - standing state and reject the reception of the control command. In such a case, the specific power storage device may store in advance the constraint information for specifying the first condition.

[0117] Note that, similar to the embodiment, the first condition may be defined based on whether the second condition is satisfied. In such a case, the specific power storage device may store in advance the configuration information for determining whether the second condition is satisfied.

[0118] Second, the specific power storage device may be a power storage device to which an operation in which switching from an interconnected state to a self - supporting state is not permitted is applied when the first condition is not satisfied. The operation may be an operation defined by the manufacturer of the specific power storage device. The operation may be an operation defined by the user of the facility 100. The operation may be an operation defined by the operator who manages the power management server 200.

[0119] [Other Embodiments] Although the present invention has been described by the above - mentioned embodiments, the discussions and drawings that form a part of this disclosure should not be understood as limiting this invention. Various alternative embodiments, examples, and operation techniques will be apparent to those skilled in the art from this disclosure.

[0120] In the above - mentioned disclosure, a case where the control unit for controlling the power storage device is the control unit 230 of the power management server 200 has been exemplified. However, the above - mentioned disclosure is not limited to this. The control unit for controlling the power storage device may be the control unit 163 of the EMS 160.

[0121] Although not particularly mentioned in the above - mentioned disclosure, after the operation of the power storage device 140 switches to the self - operation, the remaining charge amount of the power storage device 140 may exceed the upper limit constraint remaining amount.

[0122] In the above - mentioned disclosure, the power management server 200 controls the charging or discharging of the power storage device 140 so that the remaining charge amount of the power storage device 140 does not exceed the upper limit constraint remaining amount in the specific control. That is, the upper limit constraint remaining amount is a value that defines the upper limit of the remaining charge amount of the power storage device 140. However, the above - mentioned disclosure is not limited to this. In the specific control, the power management server 200 may control the charging or discharging of the power storage device 140 so that the remaining charge amount of the power storage device 140 does not fall below the lower limit constraint remaining amount. That is, the lower limit constraint remaining amount may be a value that defines the lower limit of the remaining charge amount of the power storage device 140. In such a case, the first condition may include the condition that the remaining charge amount of the power storage device 140 is equal to or more than the lower limit constraint remaining amount.

[0123] According to such a configuration, it is possible to secure a dischargeable capacity in the self - standing state. The read - replacement control of the above - mentioned modification example 4 may be applied to the case where the lower - limit constraint remaining amount is determined. Note that both the upper - limit constraint remaining amount and the lower - limit constraint remaining amount may be determined.

[0124] In the above - mentioned disclosure, the case where the upper - limit constraint remaining amount is represented by SOC is exemplified. However, the above - mentioned disclosure is not limited to this. The upper - limit constraint remaining amount may be represented by kWh.

[0125] In the above - mentioned disclosure, the power storage device 140 is exemplified as the specific power storage device for which the first condition is determined. However, the above - mentioned disclosure is not limited to this. The specific power storage device may include the power storage device 120. Alternatively, even when the specific power storage device is the power storage device 140, the power storage device 140 may be a stationary power storage device instead of an in - vehicle power storage device.

[0126] In the above - mentioned disclosure, the first condition may be a condition applied in the case where the second condition is satisfied, or may be a condition not applied in the case where the second condition is not satisfied.

[0127] Here, when the first condition is a condition applied in the case where the second condition is satisfied, the following cases are assumed. For example, when a specific distributed power source capable of supplying power to the power storage device 140 in the self - standing state is installed in the facility 100, a specific control for controlling the specific power storage device so that the remaining power storage amount of the specific power storage device does not exceed the upper - limit constraint remaining amount may be assumed to be executed. On the other hand, when the first condition is a condition not applied in the case where the second condition is not satisfied, the following cases are assumed. For example, when the specific distributed power source is not installed in the facility 100, a specific control for controlling the specific power storage device so that the remaining power storage amount of the specific power storage device satisfies the first condition is not executed, and a control in which the remaining power storage amount of the specific power storage device exceeds the upper - limit constraint remaining amount may be assumed to be allowed.

[0128] Further, the first condition may not be defined based on the second condition. That is, the first condition may be applied regardless of whether the second condition is satisfied.

[0129] Although not particularly mentioned in the above disclosure, the condition for the power storage device 140 to switch from the connected state to the self - standing state may be referred to as a predetermined condition. In such a case, it may be considered that the predetermined condition includes at least the first condition. It may also be considered that the predetermined condition includes the first condition and the second condition.

[0130] Although not particularly mentioned in the above disclosure, the specific power storage device (for example, the power storage device 140) may be installed indoors in the facility 100 or outdoors in the facility 100.

[0131] In the above - mentioned disclosure, the method by which the EMS 160 or the power management server 200 acquires the constraint information for specifying the first condition has been described (see FIGS. 6 - 9). For example, in the case shown in FIG. 6, the constraint information may be stored in advance in the storage unit of the EMS 160. The storage unit may be provided in the control unit 163. In the case shown in FIG. 7, the constraint information may be stored in advance in the storage unit of the power management server 200. The storage unit may be provided in the control unit 230 or in the management unit 210. In the cases shown in FIGS. 8 and 9, the constraint information may be stored in the power storage device 140.

[0132] In the above - mentioned disclosure, the method by which the EMS 160 or the power management server 200 acquires the configuration information for determining whether the second condition is satisfied has been described (see FIGS. 6 - 7). For example, in the case shown in FIG. 6, the configuration information may be stored in advance in the storage unit of the EMS 160. The storage unit may be provided in the control unit 163. In the case shown in FIG. 7, the configuration information may be stored in advance in the storage unit of the power management server 200. The storage unit may be provided in the control unit 230 or in the management unit 210.

[0133] Although not particularly limited, the EMS 160 and the power management server 200 may manage the acquired configuration information. That is, the EMS 160 and the power management server 200 may manage information indicating whether a distributed power source other than the power storage device 140 is connected to the upstream side (power grid 12 side) of the power storage device 140 or whether a distributed power source other than the power storage device 140 is connected to the downstream side (opposite side of the power grid 12) of the power storage device 140. The EMS 160 and the power management server 200 may manage information indicating the equipment capacity of a distributed power source other than the power storage device 140, and may manage information indicating the type of a distributed power source other than the power storage device 140. The EMS 160 and the power management server 200 may manage whether the configuration information on the self-sustaining state of the facility 100 is different from the configuration information on the interlinked state of the facility 100.

[0134] In the above-described disclosure, ECHONET Lite (registered trademark) has been mainly described. However, the above-described disclosure is not limited thereto. The above-described disclosure is also applicable to other protocols such as SEP 2.0 and KNX.

[0135] Although not particularly mentioned in the above-described disclosure, at least a part of the functions of the EMS 160 may be executed by a server arranged on the network 11. In other words, the EMS 160 may be provided by a cloud service.

[0136] The above-described disclosure may have the problems and effects shown below.

[0137] Specifically, a facility having a power storage device may be considered to have a distributed power source such as a solar power generation device. In such a case, it is necessary to assume that the generated power of the solar power generation device is charged to the power storage device in the self-sustaining state in which the facility is disconnected from the power grid.

[0138] Under such circumstances, as a result of intensive studies, the inventors have found that when the power storage device switches from the connected state where the facility is connected to the power grid to the self-sufficient state, it is necessary to consider that the remaining charge of the power storage device (for example, SOC; State Of Charge) needs to meet a predetermined condition. That is, the inventors have found that if the remaining charge of the power storage device does not meet the predetermined condition, there is a possibility that the power storage device cannot switch from the operation in the connected state (hereinafter referred to as the connected operation) to the operation in the self-sufficient state (hereinafter referred to as the self-sufficient operation).

[0139] According to the above disclosure, it is made to solve the above-described problems, and it is possible to provide a power system and a control method that enable appropriate switching of the operation of the power storage device from the connected operation to the self-sufficient operation.

Explanation of Signs

[0140] 1…Power management system, 11…Network, 12…Power grid, 100…Facility, 110…Solar cell device, 120…Power storage device, 130…Fuel cell device, 140…Power storage device, 150…Load equipment, 160…EMS, 161…First communication unit, 162…Second communication unit, 163…Control unit, 190…Measuring device, 200…Power management server, 210…Management unit, 220…Communication unit, 230…Control unit

Claims

1. A power storage device installed in a facility connected to a power system, and a control unit that controls the power storage device, wherein the control unit, determines whether a first condition that the remaining charge amount of the power storage device should satisfy is defined as a condition for the power storage device to switch from a connected state in which the facility is connected to the power system to an islanded state in which the facility is disconnected from the power system, and when the power storage device is a specific power storage device for which the first condition is defined, executes specific control to control the specific power storage device so that the remaining charge amount of the specific power storage device satisfies the first condition. A power system.

2. The first condition is defined based on whether a configuration related to a distributed power source other than the specific power storage device installed in the facility satisfies a second condition, and the control unit executes the specific control when the configuration related to the distributed power source satisfies the second condition and the first condition is defined. The power system according to claim 1.

3. The specific control is control for controlling the specific power storage device before the timing so that the remaining charge amount of the specific power storage device satisfies the first condition at the timing of switching from the connected state to the islanded state. The power system according to claim 1.

4. A power storage device installed in a facility connected to a power system, and a control unit that controls the power storage device, wherein the control unit, determines whether a first condition that the remaining charge amount of the power storage device should satisfy is defined as a condition for the power storage device to switch from a connected state in which the facility is connected to the power system to an islanded state in which the facility is disconnected from the power system, when the power storage device is a specific power storage device for which the first condition is defined, executes specific control to control the specific power storage device so that the remaining charge amount of the specific power storage device satisfies the first condition, The control unit executes a reading control for reading the remaining charge amount of the specific power storage device as a remaining charge amount different from the actual remaining charge amount during the period in which the specific control is being executed, in a power system.

5. The specific power storage device When the first condition is satisfied, after switching from the interconnected state to the self - supporting state, it receives a control command transmitted from the control unit, When the first condition is not satisfied, without switching from the interconnected state to the self - supporting state, it stops receiving the control command transmitted from the control unit, according to the power system described in claim 1.

6. The specific power storage device is a power storage device to which an operation in which switching from the interconnected state to the self - supporting state is not allowed is applied when the first condition is not satisfied, according to the power system described in claim 1.

7. A control method comprising step A of controlling a power storage device installed in a facility connected to a power system, The step A As a condition for the power storage device to switch from the interconnected state in which the facility is interconnected to the power system to the self - supporting state in which the facility is disconnected from the power system, a step of determining whether a first condition that the remaining charge amount of the power storage device should satisfy is defined, When the power storage device is a specific power storage device for which the first condition is defined, a step of executing specific control for controlling the specific power storage device so that the remaining charge amount of the specific power storage device satisfies the first condition.

8. A control method comprising step A of controlling a power storage device installed in a facility connected to a power system, The step A As a condition for the power storage device to switch from the interconnected state in which the facility is interconnected to the power system to the self - supporting state in which the facility is disconnected from the power system, a step of determining whether a first condition that the remaining charge amount of the power storage device should satisfy is defined, When the power storage device is the specific power storage device defined by the first condition, executing specific control for controlling the specific power storage device so that the remaining power storage amount of the specific power storage device satisfies the first condition; During the period in which the specific control is being executed, executing reading control for reading the remaining power storage amount of the specific power storage device as a remaining power storage amount different from the actual remaining power storage amount. A control method comprising the steps of.

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