JP2023109296A - Electric power system and control method - Google Patents

Abstract

To provide an electric power system and a control method capable of allowing operation of a power storage device to have flexibility.SOLUTION: A power control system comprises: a power storage device installed in a facility; and a controller for controlling the power storage device. The controller performs a first control that uses a first depth of discharge as a depth of discharge of the power storage device when a first condition related to deterioration of the power storage device is not satisfied, and performs a second control that uses a second depth of discharge larger than the first depth of discharge as a depth of discharge of the power storage device when the first condition related to deterioration of the power storage device is satisfied.SELECTED DRAWING: Figure 3

Description

The present invention relates to power systems and control methods.

In recent years, in order to maintain the balance of power supply and demand in a power system, a technology that uses a power storage device as a distributed power supply (for example, VPP (Virtual Power Plant)) is known (for example, Patent Documents 1 and 2). A power storage device may be used as the power source.

International Publication No. 2015/041010 Pamphlet International Publication No. 2016/084396 Pamphlet

By the way, the use of the system capacity utilization rate (%) as an index representing the performance of the power storage device is under study. System capacity utilization (%) may be represented by effective capacity (kWh)/total capacity (kWh). Effective capacity (kWh) may be expressed by total capacity (kWh) x depth of discharge (%) x system discharge efficiency (%). Depth of discharge may be referred to as DOD. DOD is a value that affects capacity deterioration of the power storage device, and is a value that can be set by the manufacturer of the power storage device or the like.

Under such circumstances, assuming a case where a power storage device is used to maintain the power supply and demand balance of the power system, if the DOD is fixed at one value, the power supply and demand of the power system You may not be able to maintain your balance properly.

Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a power system and a control method that enable flexible operation of a power storage device.

One aspect of the disclosure includes a power storage device installed in a facility, and a control unit that controls the power storage device. A first control using a first depth of discharge as the depth of discharge of the device is performed, and when a first condition regarding deterioration of the power storage device is satisfied, a second depth of discharge greater than the first depth of discharge is performed as the depth of discharge of the power storage device. A power system that executes a second control using depth of discharge.

One aspect of the disclosure includes step A of controlling a power storage device installed in a facility, wherein step A sets the depth of discharge of the power storage device to a first executing a first control using the depth of discharge; and using a second depth of discharge greater than the first depth of discharge as the depth of discharge of the power storage device when a first condition regarding deterioration of the power storage device is satisfied. 2. A control method, comprising the step of performing control.

ADVANTAGE OF THE INVENTION According to this invention, the electric power system and control method which can give flexibility to operation|use of an electrical storage apparatus can be provided.

FIG. 1 is a diagram showing a power management system 1 according to an embodiment. FIG. 2 is a diagram showing a facility 100 according to an embodiment. FIG. 3 is a diagram showing the power storage device 120 according to the embodiment. FIG. 4 is a diagram showing the EMS 160 according to the embodiment. FIG. 5 is a diagram for explaining the system capacity utilization rate according to the embodiment; FIG. 6 is a diagram for explaining the system capacity utilization rate according to the embodiment; FIG. 7 is a diagram for explaining first control and second control according to the embodiment. FIG. 8 is a diagram for explaining first control and second control according to the embodiment. FIG. 9 is a diagram for explaining first control and second control according to the embodiment. FIG. 10 is a diagram for explaining first control and second control according to the embodiment.

Embodiments will be described below with reference to the drawings. In addition, in the following description of the drawings, the same or similar reference numerals are given to the same or similar parts. However, the drawings are schematic.

[Embodiment]
(power management system)
A power management system according to an embodiment will be described below. A power management system may simply be referred to as a power system.

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

Here, facility 100 and power management server 200 are configured to be able to communicate via 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.

Facility 100 is connected to power grid 12 and may receive power from power grid 12 or may supply power to power grid 12 . Power from power system 12 to facility 100 may be referred to as tidal power, purchased power, or demand power. Power from facility 100 to power system 12 may be referred to as reverse flow power or sold power. In FIG. 1, as the facility 100, facilities 100A to 100C are illustrated.

Although not particularly limited, the facility 100 may be a facility such as a residence, a facility such as a store, or a facility such as an office. Facility 100 may be an apartment complex containing two or more residences. The facility 100 may be a complex facility including at least two or more facilities of residences, shops, and offices. Details of facility 100 will be described later (see FIG. 2).

The power management server 200 is managed by an operator who manages power related to the power system 12 . The business may be a power generation business, a power transmission and distribution business, or a retail electricity business. The provider may be a resource aggregator (hereinafter referred to as RA) or an aggregation coordinator (AC) that manages RAs. The RA may be a business operator that adjusts the power supply and demand balance of the power system 12 . The adjustment of the power supply and demand balance may include trading (hereinafter referred to as negawatt trading) in which the reduced power of the facility 100 (tidal power) is exchanged for value. Adjusting the power supply and demand balance may include trading increased power of reverse flow power for value. An RA may be a business such as a power generation company, a power transmission/distribution company and a retail electricity company in a VPP.

In an embodiment, communication between power management server 200 and EMS 160 is performed according to a first protocol. On the other hand, communication between EMS 160 and distributed power sources (solar cell device 110, power storage device 120, or fuel cell device 130) is performed according to a second protocol different from the first protocol. For example, as the first protocol, a protocol conforming to Open ADR (Automated Demand Response) or a unique dedicated protocol can be used. For example, the second protocol can use a protocol conforming to ECHONET Lite (registered trademark), SEP (Smart Energy Profile) 2.0, KNX, or a unique proprietary protocol. The first protocol and the second protocol may be different. For example, even if both are proprietary protocols, they may be protocols created according to different rules. However, the first protocol and the second protocol may be protocols created according to the same rules.

(institution)
A facility according to the embodiment will be described below. As shown in FIG. 2, the facility 100 has a solar cell device 110, a power storage device 120, a fuel cell device 130, a load device 140, and an EMS (Energy Management System) 160. Facility 100 may have measurement device 190 .

The solar cell device 110 is a distributed power source that generates power according to light such as sunlight. For example, the solar cell device 110 is composed of a PCS (Power Conditioning System) and a solar panel. Here, the installation may be the connection between the solar cell device 110 and the power system 12 .

The power storage device 120 is a distributed power source that charges and discharges power. For example, the power storage device 120 is composed of PCS and power storage cells. Here, installation may be the connection of power storage device 120 and power system 12 .

The fuel cell device 130 is a distributed power source that uses fuel to generate power. For example, the fuel cell device 130 is composed of PCS and fuel cells. Here, "installation" may mean that the fuel cell device 130 and the power system 12 are connected.

For example, the fuel cell device 130 may be a solid oxide fuel cell (SOFC), a polymer electrolyte fuel cell (PEFC), or a phosphoric acid fuel cell. It may be a type fuel cell (PAFC; Phosphoric Acid Fuel Cell) or a molten carbonate type fuel cell (MCFC; Molten Carbonate Fuel Cell).

The load device 140 is a device that consumes electric power, such as the power system 12, the solar cell device 110, the power storage device 120, and the fuel cell device . For example, the load device 140 may include an air conditioner that adjusts the temperature of a predetermined space in the facility 100, or a lighting device that adjusts the illuminance of a predetermined space in the facility 100. FIG. Load devices 140 may include video equipment, audio equipment, refrigerators, washing machines, personal computers, and the like.

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

Measurement device 190 measures the power flowing from power system 12 to facility 100 . Measurement device 190 may measure reverse power flow from facility 100 to power system 12 . For example, metering device 190 may be a Smart Meter belonging to a power company. The measuring device 190 may transmit to the EMS 160 every first interval an information element indicating the measurement result (integrated value of the power flow or reverse flow power) at the first interval (for example, 30 minutes). The measurement device 190 may send an information element to the EMS 160 indicating the measurement result at a second interval (eg, 1 minute) that is shorter than the first interval.

(Power storage device)
Power storage devices according to embodiments will be described below. As shown in FIG. 3 , the power storage device 120 has a BT 121 and a controller 122 . Although omitted in FIG. 3, the power storage device 120 may include a PCS.

BT 121 is a power storage cell included in power storage device 120 . The control unit 122 controls the BT121. In the embodiment, control unit 122 may be an example of a control unit that controls power storage device 120 .

Although not particularly limited, the control unit 122 may control the BT 121 based on commands received from the EMS 160 or may control the BT 121 based on commands received from the power management server 200 . In such a case, power storage device 120 may have a communication unit configured by a communication module.

For example, controller 122 may include at least one processor. The at least one processor may be formed by a single integrated circuit (IC), or by a plurality of communicatively coupled circuits (such as integrated circuits and/or discrete circuit(s)). good too.

In the embodiment, control unit 122 executes first control using a first depth of discharge (hereinafter referred to as first DOD) as the depth of discharge of power storage device 120 when a first condition regarding deterioration of power storage device 120 is not satisfied. Control unit 122 executes second control using a second depth of discharge (hereinafter referred to as second DOD) greater than the first DOD as the depth of discharge of power storage device 120 when a first condition regarding deterioration of power storage device 120 is satisfied. . Details of the first control and the second control will be described later.

Note that the depth of discharge is a term that means the ratio of the amount of discharge to the capacity of the power storage device 120 (see FIG. 5, for example). The depth of discharge may be a value that can be set by the manufacturer of power storage device 120 or the like.

(EMS)
The EMS according to the embodiment will be described below. As shown in FIG. 4, the EMS 160 has a first communication section 161, a second communication section 162, and a control section 163.

The first communication unit 161 is configured by a communication module. The communication module can be a wireless communication module that conforms to standards such as IEEE802.11a/b/g/n/ac/ax, ZigBee, Wi-SUN, LTE, 5G, 6G, and standards such as IEEE802.3 may be a wired communication module conforming to

For example, the first communication unit 161 communicates with the power management server 200 via the network 11. FIG. The first communication unit 161 performs communication according to the first protocol, as described above. For example, the first communication unit 161 receives the first message from the power management server 200 according to the first protocol. The first communication unit 161 transmits the first message response to the power management server 200 according to the first protocol.

The second communication unit 162 is configured by a communication module. The communication module can be a wireless communication module that conforms to standards such as IEEE802.11a/b/g/n/ac/ax, ZigBee, Wi-SUN, LTE, 5G, 6G, and standards such as IEEE802.3 may be a wired communication module conforming to

For example, the second communication unit 162 communicates with devices included in the facility 100 (the solar cell device 110, the power storage device 120, the fuel cell device 130). The second communication unit 162 communicates according to the second protocol, as described above. For example, the second communication unit 162 transmits the second message to the distributed power sources according to the second protocol. The second communication unit 162 receives the second message response from the distributed power sources according to the second protocol.

Control unit 163 may include at least one processor. The at least one processor may be formed by a single integrated circuit (IC), or by a plurality of communicatively coupled circuits (such as integrated circuits and/or discrete circuit(s)). good too.

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

(System capacity utilization rate)
The system capacity utilization rate according to the embodiment will be described below. System capacity utilization (%) may be represented by effective capacity (kWh)/total capacity (kWh). Effective capacity (kWh) may be expressed by total capacity (kWh) x depth of discharge (%) x system discharge efficiency (%). The effective capacity (kWh) used in calculating the system capacity utilization rate (%) may be the initial value of the effective capacity (kWh).

As shown in FIG. 5, the total capacity (kWh) of the power storage device 120 may include a capacity equal to or lower than the lower limit threshold value T _LOWER (unusable region (discharge) in FIG. 5). The unusable area (discharge) is an area in which the discharge of power storage device 120 is restricted. The unusable region (discharge) is a region that can affect the deterioration of power storage device 120 and may be determined by the characteristics of power storage device 120 .

When emergency capacity (BCP (Business Continuity Plan) capacity) is defined to respond to emergencies such as disasters, the BCP capacity is defined as the difference between a threshold T _BCP larger than the lower threshold T _LOWER and the lower threshold T _LOWER . is the capacity between That is, the unusable area (discharge) is an area different from the BCP capacity.

On the other hand, the total capacity (kWh) of the power storage device 120 may include a capacity equal to or higher than the upper threshold value T _UPPER (unusable region (charging) in FIG. 5). The unusable area (charging) is an area where charging of power storage device 120 is restricted. The unusable region (charging) is a region that can affect the deterioration of power storage device 120 and may be determined by the characteristics of power storage device 120 . The unusable area (charging) may be thought of as the portion lost due to system discharge efficiency (%).

Under this premise, the depth of discharge (%) may be represented by (total capacity (kWh)-unusable area (discharge))/total capacity (kWh). For example, if the total capacity (kWh) is 10 kWh and the unusable area (discharge) is 0.5 kWh, the capacity based on depth of discharge is 9.5 kWh and the depth of discharge (%) is 95%. If the system discharge efficiency (%) is 90%, the effective capacity is 8.55 kWh and the system capacity utilization (%) is 85.5%. Similarly, if the total capacity (kWh) is 10 kWh and the unusable area (discharge) is 1.5 kWh, the capacity based on depth of discharge is 8.5 kWh and the depth of discharge (%) is 85%. . If the system discharge efficiency (%) is 90%, the effective capacity is 7.65 kWh and the system capacity utilization (%) is 76.5%.

Although not particularly limited, the system discharge efficiency (%) may be considered as a concept included in the discharge depth (%). For example, depth of discharge (%) may be represented by effective capacity (kWh)/total capacity (kWh). Note that the effective capacity (kWh) is the capacity (kWh) between the lower threshold T _LOWER and the upper threshold T _UPPER . That is, the depth of discharge (%) may be synonymous with the system capacity utilization rate (%).

Here, the effective capacity (kWh) may be variable depending on the temperature of power storage device 120 . The temperature of power storage device 120 may be the surface temperature of BT 121 (power storage cell) or the internal temperature of the housing of power storage device 120 .

For example, when the total capacity (kWh) is 10.0 kWh, the effective capacity (kWh) may be displayed in the manner shown in the upper part of FIG. For example, when the temperature of power storage device 120 is 25° C., the effective capacity (kWh) is 8.55 kWh, and when the temperature of power storage device 120 is −10° C., the effective capacity (kWh) is 8.50 kWh. , when the temperature of power storage device 120 is 40° C., the effective capacity (kWh) may be 8.33 kWh.

In such a case, the system capacity utilization (%) may be displayed in the manner shown in the lower part of FIG. For example, when the temperature of power storage device 120 is 25° C., the system capacity utilization rate (%) is 85.5%, and when the temperature of power storage device 120 is −10° C., the system capacity utilization rate (%) is 85.0%, and the temperature of power storage device 120 is 40° C., the system capacity utilization rate (%) may be 83.3%.

(1st control and 2nd control)
First control and second control according to the embodiment will be described below. As described above, the first control is control using the first DOD as the depth of discharge of power storage device 120 . The second control is control using the second DOD as the depth of discharge of power storage device 120 . In the following, for simplification of explanation, a case where the system discharge efficiency (%) is included in the discharge depth (%) will be explained. That is, a case will be described where the depth of discharge (%) is synonymous with the system capacity utilization rate (%).

First, a case in which power storage device 120 is charged will be described with reference to FIG. In the first control, the effective capacity (kWh) is the capacity between the lower threshold T _LOWER and the threshold T1. Threshold T1 may be considered to be the upper threshold T _UPPER described above. The first DOD is represented by the capacity/total capacity between the lower threshold T _LOWER and the threshold T1. In contrast, in the second control, the effective capacity (kWh) is the capacity between the lower threshold T _LOWER and the threshold T2. The threshold T2 is a value larger than the threshold T1. The second DOD is represented by the volume/total volume between the lower threshold T _LOWER and the threshold T2. In other words, in the second control, it may be considered that at least part of the unusable area (charging) is released and the unusable area (charging) is used as the effective capacity. That is, by changing the threshold T1 to the threshold T2, the first DOD is changed to a second DOD that is larger than the first DOD.

Second, the case of executing the discharge of the power storage device 120 will be described with reference to FIG. In the first control, the effective capacity (kWh) is the capacity between the threshold T1 and the upper threshold T _UPPER . Threshold T1 may be considered to be the lower threshold T _LOWER discussed above. The first DOD is represented by the capacity between the threshold T1 and the capacity between the upper threshold T _UPPER /total capacity. On the other hand, in the second control, the effective capacity (kWh) is the capacity between the threshold T2 and the upper limit threshold T _UPPER . The threshold T2 is a value smaller than the threshold T1. The second DOD is represented by the capacity/total capacity between the threshold T2 and the upper threshold _{T_UPPER} . In other words, in the second control, it may be considered that at least part of the unusable area (discharge) is released and the unusable area (discharge) is used as the effective capacity. That is, by changing the threshold T1 to the threshold T2, the first DOD is changed to a second DOD that is larger than the first DOD.

Under this premise, control unit 122 of power storage device 120 executes the first control using the first DOD when the first condition regarding deterioration of power storage device 120 is not satisfied. Control unit 122 executes the second control using the second DOD when the first condition regarding the deterioration of power storage device 120 is satisfied.

The first condition may be a condition related to deterioration of power storage device 120 . For example, the definition may be based on at least one selected from a first parameter regarding deterioration of power storage device 120 and a second parameter regarding use of power storage device 120 .

The first parameter may be one or more parameters selected from the temperature of power storage device 120, the capacity deterioration rate of power storage device 120, the SOH (State of Health) of power storage device 120, and the effective capacity of power storage device 120. good. The temperature of power storage device 120 may be the surface temperature of BT 121 (power storage cell) or the internal temperature of the housing of power storage device 120 . When the initial SOH is 100%, the capacity deterioration rate may be represented by current SOH/initial SOH, or may be represented by current effective capacity/initial effective capacity.

In option 1-1, the first condition may be that the temperature of power storage device 120 is below the threshold. Control unit 122 may execute first control when the temperature of power storage device 120 is equal to or higher than the threshold, and may execute second control when the temperature of power storage device 120 is below the threshold. The first condition may be that the temperature of power storage device 120 from start to stop of power storage device 120 satisfies a predetermined temperature condition. Control unit 122 may execute the first control when the temperature of power storage device 120 satisfies a predetermined temperature condition, and execute the second control when the temperature of power storage device 120 does not satisfy the predetermined temperature condition. Although not particularly limited, the predetermined temperature condition may be a condition that defines the temperature range of power storage device 120 from start to stop (for example, -10°C to 40°C).

In option 1-2, the first condition may be that the capacity deterioration rate of power storage device 120 is less than the threshold. Control unit 122 may execute first control when the capacity deterioration rate of power storage device 120 is equal to or greater than the threshold, and may execute second control when the capacity deterioration rate of power storage device 120 is less than the threshold.

In option 1-3, the first condition may be that the SOH of power storage device 120 is greater than or equal to the threshold. Control unit 122 may perform first control when the SOH of power storage device 120 is less than the threshold, and may perform second control when the SOH of power storage device 120 is greater than or equal to the threshold.

In option 1-4, the first condition may be that the effective capacity of power storage device 120 is greater than or equal to the threshold. Control unit 122 may execute first control when the effective capacity of power storage device 120 is less than the threshold, and may execute second control when the effective capacity of power storage device 120 is equal to or greater than the threshold.

Two or more options selected from options 1-1 to 1-4 described above may be combined.

The second parameter is one or more parameters selected from the accumulated usage time of power storage device 120, the number of charge/discharge cycles of power storage device 120, the accumulated discharged power of power storage device 120, and the accumulated charged power of power storage device 120. good too. The cumulative usage time of power storage device 120 may be the sum of the discharge time and the charge time, or the sum of the discharge time, the charge time, and the standby time.

In option 2-1, the first condition may be that the cumulative usage time of power storage device 120 is less than the threshold. Control unit 122 may execute the first control when the accumulated usage time of power storage device 120 is equal to or greater than the threshold, and execute the second control when the accumulated usage time of power storage device 120 is less than the threshold.

In Option 2-2, the first condition may be that the number of charge/discharge cycles of power storage device 120 is less than a threshold. Control unit 122 executes the first control when the number of charge/discharge cycles of power storage device 120 is equal to or greater than the threshold, and executes the second control when the number of charge/discharge cycles of power storage device 120 is less than the threshold. good.

In Option 2-3, the first condition may be that the accumulated discharged power of power storage device 120 is less than the threshold. Control unit 122 may execute first control when the accumulated discharged power of power storage device 120 is equal to or greater than the threshold, and may execute second control when the accumulated discharged power of power storage device 120 is less than the threshold.

In Option 2-4, the first condition may be that the accumulated charging power of power storage device 120 is less than the threshold. Control unit 122 may execute the first control when the accumulated charged power of power storage device 120 is equal to or greater than the threshold, and may execute the second control when the accumulated charged power of power storage device 120 is less than the threshold.

Two or more options selected from options 2-1 to 2-4 described above may be combined.

Furthermore, the first condition may be defined by both the first parameter and the second parameter. In the following, the capacity loss rate is exemplified as the first parameter, and the number of charge/discharge cycles (Cycle) is exemplified as the second parameter. However, the capacity deterioration rate may be replaced with another first parameter, and the number of charge/discharge cycles may be replaced with another second parameter.

As shown in FIG. 9, the relationship between the capacity deterioration rate and the number of charge/discharge cycles can be represented by a deterioration curve. The ideal deterioration curve is a deterioration curve assuming a case where only the first control is executed. The permissible deterioration curve is a permissible deterioration curve in the case where the first control and the second control coexist. For example, when the life of the power storage device 120 is defined by the maximum capacity deterioration rate (maximum capacity loss=50% in FIG. 9), the ideal deterioration curve reaches the maximum capacity deterioration rate (A in FIG. 9). The number of charge/discharge cycles may be 7,000, and the number of charge/discharge cycles may be 6,700 at the timing when the allowable deterioration curve reaches the maximum capacity deterioration rate (B in FIG. 9). The divergence between the ideal deterioration curve and the allowable deterioration curve may increase as the number of charge/discharge cycles increases.

Under such a premise, the first control and the second control will be described by taking the X portion shown in FIG. 9 as an example. FIG. 10 shows an enlarged view of the X portion shown in FIG. From the viewpoint of simplification of explanation, a case in which the ideal deterioration curve and the allowable deterioration curve are substantially parallel in the X portion will be exemplified.

As shown in FIG. 10, the slope of the deterioration curve associated with the first control is the same as the slope of the ideal deterioration curve (here, the ideal deterioration curve and the allowable deterioration curve). On the other hand, the slope of the deterioration curve associated with the second control is greater than the slope of the ideal deterioration curve (here, the ideal deterioration curve and the allowable deterioration curve). The first control and the second control are executed such that the deterioration curve of power storage device 120 changes between the ideal deterioration curve and the allowable deterioration curve. Therefore, for example, as shown in FIG. 10, in the case where the deterioration curve of power storage device 120 reaches the allowable deterioration curve at C, the second control is not executed after C, and the first control is executed.

The following two options are conceivable as a method of realizing such control. In either option, the capacity degradation rate may be calculated for each specific cycle. Although not particularly limited, the specific cycle may be 1 cycle, 10 cycles, or 100 cycles.

In Option 3-1, a target capacity deterioration rate to be met when the number of charge/discharge cycles reaches a predetermined number of cycles may be set. A target capacity degradation rate may be defined by the allowable degradation curve described above. Control unit 122 determines whether or not the first condition is satisfied based on the result of comparison between the actual capacity deterioration rate and the target capacity deterioration rate when the number of charge/discharge cycles reaches the predetermined number of cycles. Specifically, control unit 122 determines that the first condition is satisfied if the actual capacity deterioration rate is smaller than the target capacity deterioration rate. On the other hand, if the actual capacity deterioration rate is greater than the target capacity deterioration rate, control unit 122 determines that the first condition is not satisfied. Control unit 122 may execute the first control or the second control when the actual capacity deterioration rate is equal to the target capacity deterioration rate. As the predetermined number of cycles, a predetermined number of cycles of 2 or more (for example, 1,000, 3,000, 5,000, etc.) may be set.

That is, in Option 3-1, it is only necessary to intermittently determine whether the first condition is satisfied. In other words, the determination of whether the first condition is satisfied may be omitted before the number of charge/discharge cycles reaches the predetermined number of cycles. Therefore, it is possible to reduce the processing load involved in determining whether or not the first condition is satisfied.

As described above, the capacity deterioration rate may be replaced with another first parameter, and the number of charge/discharge cycles may be replaced with another second parameter. That is, option 3-1 may be expressed as shown below. A target is defined for the first parameter to be met when the second parameter reaches a predetermined parameter. When the second parameter reaches the predetermined parameter, control unit 122 determines whether or not the first condition is satisfied based on the result of comparison between the performance of the first parameter and the target of the first parameter.

In option 3-2, a target number of charge/discharge cycles to be met when the capacity deterioration rate reaches a predetermined deterioration rate may be set. The target number of charge/discharge cycles may be defined by the allowable aging curve described above. When the capacity deterioration rate reaches the predetermined deterioration rate, control unit 122 determines whether or not the first condition is satisfied based on the result of comparison between the actual number of charge/discharge cycles and the target number of charge/discharge cycles. . Specifically, control unit 122 determines that the first condition is satisfied if the actual number of charge/discharge cycles is greater than the target number of charge/discharge cycles. On the other hand, if the actual number of charge/discharge cycles is less than the target number of charge/discharge cycles, control unit 122 determines that the first condition is not satisfied. Control unit 122 may execute the first control or the second control when the actual number of charge/discharge cycles is equal to the target number of charge/discharge cycles. As the predetermined deterioration rate, two or more predetermined deterioration rates (for example, 10%, 20%, 30%, etc.) may be set. Here, in the case where the actual number of charge/discharge cycles when the capacity deterioration rate reaches the predetermined deterioration rate is greater than the target number of charge/discharge cycles, the number of charge/discharge cycles when the capacity deterioration rate reaches the predetermined deterioration rate It should be noted that the deterioration of the capacity of power storage device 120 has not progressed relatively compared to the case where the actual number of charge/discharge cycles is less than the target number of charge/discharge cycles.

That is, in option 3-2, it is only necessary to intermittently determine whether the first condition is satisfied. In other words, the determination of whether the first condition is satisfied may be omitted before the number of charge/discharge cycles reaches the predetermined number of cycles. Therefore, it is possible to reduce the processing load involved in determining whether or not the first condition is satisfied.

As described above, the capacity deterioration rate may be replaced with another first parameter, and the number of charge/discharge cycles may be replaced with another second parameter. That is, Option 3-2 may be expressed as shown below. A target is defined for the second parameter to be met when the first parameter reaches a predetermined parameter. When the first parameter reaches the predetermined parameter, control unit 122 determines whether or not the first condition is satisfied based on the result of comparison between the performance of the second parameter and the target of the second parameter.

(Action and effect)
In the embodiment, power storage device 120 executes the first control using the first DOD as the depth of discharge of power storage device 120 when the first condition regarding deterioration of power storage device 120 is not satisfied. Power storage device 120 executes second control using a second DOD larger than the first DOD as the depth of discharge of power storage device 120 when a first condition regarding deterioration of power storage device 120 is satisfied. According to such a configuration, by appropriately using the first DOD and the second DOD, the life of the power storage device 120 can be considered and the power storage device 120 can be stored as compared to the case where the DOD is fixedly determined as one value. The operation of the device 120 can be flexible.

[Modification 1]
Modification 1 of the embodiment will be described below. In the following, the differences with respect to the embodiments will be explained.

In Modification 1, control unit 122 of power storage device 120 executes the second control when the second condition for starting the second control is satisfied and the first condition is satisfied. As the second condition, the following options are conceivable.

In Option 4-1, the second condition may be defined based on the power supply and demand balance of the power system 12 connected to the facility 100. FIG. For example, the second condition may be receiving a message (request or request) regarding maintenance of the power supply and demand balance of the power system 12 . Alternatively, the second condition may be participating in maintaining the power supply and demand balance of the power system 12 . Specifically, when the control unit 122 receives a message (request or request) regarding maintenance of the power supply and demand balance of the power system 12, it determines whether both the first condition and the second condition are satisfied. may Control unit 122 executes the first control when the first condition is not satisfied. On the other hand, control unit 122 executes the second control when the first condition is satisfied.

A message regarding maintenance of the power supply and demand balance of the power system 12 may be received from the power management server 200 or may be received from the EMS 160 . The message may be a message instructing suppression of power flow to the facility 100 or a message instructing an increase in reverse power flow from the facility 100 . These messages may be messages related to so-called DR (Demand Response). Alternatively, the message may be a message instructing an increase in power flow to the facility 100 or a message instructing suppression of reverse power flow from the facility 100 . These messages may be so-called output suppression messages.

According to such a configuration, power storage device 120 can be effectively used to maintain the power supply and demand balance of power system 12 by providing flexibility in the operation of power storage device 120 .

In option 4-2, the second condition may be defined based on a prediction of possible power outages in the area including facility 100. FIG. For example, the second condition may be that a possible power outage in the area including the facility 100 is predicted. Specifically, the control unit 122 may determine whether both the first condition and the second condition are satisfied when receiving a message regarding the prediction of power outages that may occur in the area including the facility 100. . Control unit 122 executes the first control when the first condition is not satisfied. On the other hand, control unit 122 executes the second control when the first condition is satisfied.

A message regarding prediction of a power outage that may occur in the area including facility 100 may be received from power management server 200 or may be received from EMS 160 . Alternatively, messages regarding predictions of possible power outages in the area containing facility 100 may be received from an external server, such as a weather server. The message may be a message regarding prediction of natural disasters such as typhoon, heavy snow, thunder. The message may be a message regarding prediction of rolling blackouts or the like. The message may contain an information element regarding the time when the power outage is expected.

According to such a configuration, power storage device 120 can be effectively used during a power failure by providing flexibility in the operation of power storage device 120 .

Although not particularly limited, in Option 4-2, the second control is control for releasing the unusable area (charging), that is, setting the first threshold (upper limit threshold T _UPPER ) to a value greater than the first threshold. Control (see FIG. 7) for switching to two thresholds may be used.

In option 4-3, the second condition may be defined based on a prediction of power consumption that can be consumed at facility 100. FIG. For example, the second condition may be that the power consumption that can be consumed at facility 100 is predicted to exceed a threshold. Control unit 122 may determine whether both the first condition and the second condition are satisfied when receiving a message regarding the prediction that the power consumption that can be consumed in facility 100 will exceed the threshold. Control unit 122 executes the first control when the first condition is not satisfied. On the other hand, control unit 122 executes the second control when the first condition is satisfied.

A message regarding the prediction that the power consumption that can be consumed in facility 100 will exceed the threshold may be received from power management server 200 or may be received from EMS 160 . The message may include an information element regarding the expected time at which the power consumption exceeds the threshold, and may include an information element regarding the magnitude of the power consumption.

According to such a configuration, by providing flexibility in the operation of power storage device 120, power storage device 120 can be effectively used during times when facility 100 consumes a large amount of power.

Although not particularly limited, in Option 4-3, the second control is a control that releases the unusable area (discharge), that is, sets the first threshold (lower threshold T _LOWER ) to a value lower than the first threshold. Control (see FIG. 8) for switching to two thresholds may be used.

Two or more options selected from options 4-1 to 4-3 described above may be combined. Further, the business operator or the user of the facility 100 may be allowed to select whether or not to adopt the above options 4-1 to 4-3 as the second condition. Furthermore, apart from options 4-1 to 4-3 above, if the business operator or the user of the facility 100 designates a date and time (period) such as summer, and the first condition is satisfied during that period Then, the second control may be executed.

[Other embodiments]
Although the present invention has been described by the above-described embodiments, the statements and drawings forming part of this disclosure should not be construed as limiting the present invention. Various alternative embodiments, implementations and operational techniques will become apparent to those skilled in the art from this disclosure.

In the above disclosure, the case where the control unit that controls power storage device 120 is control unit 122 of power storage device 120 has been exemplified. However, the above disclosure is not so limited. The control unit that controls power storage device 120 may be control unit 163 of EMS 160 or power management server 200 . A control unit that controls power storage device 120 may be a device management server (such as an operation and maintenance server) that manages maintenance information of power storage device 120 and the like.

Although not specifically mentioned in the disclosure above, the ideal deterioration curve and allowable deterioration curve shown in FIGS. The ideal deterioration curve and the allowable deterioration curve may be stored in advance in the EMS 160, may be stored in advance in the power management server 200, or may be stored in the device management server. EMS 160 , power management server 200 or device management server may transmit the ideal deterioration curve and the allowable deterioration curve to power storage device 120 .

Although not specifically mentioned in the disclosure above, the first parameter and the second parameter may be managed by control unit 122 of power storage device 120 . The first parameter and the second parameter may be managed by EMS 160 and may be managed by power management server 200. FIG. EMS 160 or power management server 200 may transmit the first parameter and the second parameter to power storage device 120 .

Although not specifically mentioned in the above disclosure, the system capacity utilization rate may be calculated based on the second DOD.

Although not specifically mentioned in the above disclosure, at least some of the functions of EMS 160 may be executed by a server arranged on network 11 . In other words, EMS 160 may be provided by a cloud service.

DESCRIPTION OF SYMBOLS 1... Power management system, 11... Network, 12... Power system, 100... Facility, 110... Solar cell device, 120... Power storage device, 121... BT, 122... Control unit, 130... Fuel cell device, 140... Load device, 160...EMS, 161...first communication unit, 162...second communication unit, 163...control unit, 190...measuring device, 200...power management server

Claims (7)

a power storage device installed in the facility;
A control unit that controls the power storage device,
The control unit
executing first control using a first depth of discharge as the depth of discharge of the power storage device when a first condition regarding deterioration of the power storage device is not satisfied;
A power system that executes second control using a second depth of discharge greater than the first depth of discharge as the depth of discharge of the power storage device when a first condition regarding deterioration of the power storage device is satisfied. 2. The electric power according to claim 1, wherein said first condition is defined based on at least one selected from a first parameter relating to deterioration of said power storage device and a second parameter relating to use of said power storage device. system. 3. The electric power according to claim 1, wherein the control unit executes the second control when a second condition for starting the second control is satisfied and the first condition is satisfied. system. The second condition is at least one selected from the power supply and demand balance of the power system connected to the facility, prediction of power outages that may occur in an area including the facility, and prediction of power consumption that may be consumed in the facility. 4. The power system of claim 3, defined based on one. A target of the first parameter to be met when the second parameter reaches a predetermined parameter is defined,
The control unit determines whether or not the first condition is satisfied based on a comparison result between the performance of the first parameter and the target of the first parameter when the second parameter reaches the predetermined parameter. The power system of any one of claims 2, 3 or 4 reciting claim 2, determining. A target of the second parameter to be met when the first parameter reaches a predetermined parameter is defined,
The control unit determines whether or not the first condition is satisfied based on a comparison result between the performance of the second parameter and the target of the second parameter when the first parameter reaches the predetermined parameter. The power system of any one of claims 2, 3 or 4 reciting claim 2, determining. Equipped with a step A that controls the power storage device installed in the facility,
The step A is
a step of executing first control using a first depth of discharge as the depth of discharge of the power storage device when a first condition regarding deterioration of the power storage device is not satisfied;
a step of executing second control using a second depth of discharge greater than the first depth of discharge as the depth of discharge of the power storage device when a first condition regarding deterioration of the power storage device is satisfied. .