JP7553129B2 - Control device - Google Patents

Description

The present invention relates to a control device.

Technologies related to charging and discharging of energy storage systems have been proposed. For example, Patent Document 1 describes a control device that, for a plurality of energy storage systems constituting an energy storage system group, determines the charging power to be distributed in order from the energy storage system with the lowest charging rate during charging, and determines the discharging power to be distributed in order from the energy storage system with the highest charging rate during discharging.

International Publication No. 2016/152006

When using charging and discharging with a power storage system, precise charge and discharge control may be required.

One example of the objectives of the present invention is to provide a control device that can solve the above problems.

According to one aspect of the present invention, the control device determines a storage system group among a plurality of storage system groups to be charged or discharged based on an expected error value in charging and discharging of the storage system group including a plurality of storage systems and an upper limit value of an allowable error rate for the charge/discharge request amount in the service execution request, and is equipped with a command value calculation means for calculating a charge/discharge command value for the storage system group based on the accuracy of the charge/discharge control of the determined storage system group, and a command value transmission means for transmitting the charge/discharge command value.

The above-mentioned control device can meet the requirements for precision in charge/discharge control of the energy storage system.

1 is a schematic block diagram illustrating an example of a device configuration of a power system according to an embodiment. 2 is a schematic block diagram illustrating an example of a functional configuration of a higher-level control device according to the embodiment. FIG. FIG. 2 is a schematic block diagram illustrating an example of a functional configuration of an intermediate control device according to the embodiment. FIG. 2 is a diagram illustrating a configuration example of a power storage system group according to an embodiment. FIG. 1 is a diagram illustrating an example of a power storage system according to an embodiment. FIG. 2 is a diagram illustrating a first example of charge/discharge control of the power storage system according to the embodiment. FIG. 11 is a diagram illustrating a second example of control of charging and discharging the power storage system according to the embodiment. FIG. 11 is a diagram illustrating a third example of charge/discharge control of the power storage system according to the embodiment. FIG. 11 is a diagram illustrating a fourth example of charge/discharge control of the power storage system according to the embodiment. 5 is a flowchart illustrating an example of a procedure of a process performed by a higher-level control device according to the embodiment. 5 is a flowchart showing an example of a procedure of a process performed by an intermediate control device according to the embodiment. FIG. 2 is a diagram illustrating a configuration example of a control device according to the embodiment. FIG. 11 is a diagram illustrating an example of a processing procedure in a control method according to the embodiment. FIG. 1 is a schematic block diagram illustrating a configuration of a computer according to at least one embodiment.

The following describes embodiments of the present invention, but the following embodiments do not limit the scope of the invention as claimed. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

Figure 1 is a schematic block diagram showing an example of the device configuration of a power system according to an embodiment. In the configuration shown in Figure 1, the power system 1 includes a high-level control system 10, an intermediate-level control system 20, a consumer-installed system 30-1, and a large-scale charging/discharging system 30-2.

The upper level control system 10 comprises an upper level control device 11 and a gateway device 91. The intermediate level control system 20 comprises an intermediate level control device 21 and a gateway device 91. The consumer installation system 30-1 comprises a consumer lower level control device 31-1, a consumer storage system 32-1, a distribution board 41, consumer power wiring 43, a consumer load 44, a solar power generation facility 47, and a gateway device 91. The large-scale charging/discharging system 30-2 comprises a large-scale facility lower level control device 31-2, a large-scale storage system 32-2, and a gateway device 91.

The gateway devices 91 of the upper control system 10, the intermediate control system 20, the customer-installed system 30-1, and the large-scale charging/discharging system 30-2 are communicatively connected to a communication network 910. The distribution board 41 of the customer-installed system 30-1 and the large-scale storage system 32-2 of the large-scale charging/discharging system 30-2 are both connected to the power grid 920, and exchange power with the power grid 920. In Figure 1, the power paths are shown with solid lines, and the signal paths are shown with dashed lines.

The consumer power storage system 32-1 and the large-scale power storage system 32-2 are examples of power storage systems that perform charging and discharging in response to requests from the intermediate-level control system 20. A power storage system that performs charging and discharging in response to requests from the intermediate-level control system 20 is also referred to as a power storage system 32.

The power storage system 32 includes a storage battery (cell) and a power conditioning system (PCS). During charging, the power conditioning system converts AC power supplied from outside the power storage system 32 into DC power and outputs it to the storage battery, which then stores the power. During discharging, the power conditioning system converts the DC power discharged by the storage battery into AC power and outputs it to the outside of the power storage system 32.
The power conditioning system also controls charging and discharging. Specifically, the power conditioning system switches between charging, discharging, and stopping (neither charging nor discharging), and controls the amount of charging and discharging during charging and discharging.

The consumer lower-level control device 31-1 and the large-scale facility lower-level control device 31-2 are examples of devices that control the charging and discharging of the energy storage system 32, such as the consumer energy storage system 32-1 or the large-scale energy storage system 32-2, in response to a request from the intermediate-level control system 20. The device that controls the charging and discharging of the energy storage system 32 in response to a request from the intermediate-level control system 20 is also referred to as the lower-level control device 31.

The consumer-installed system 30-1 or the large-scale charging/discharging system 30-2 is an example of a system that includes a storage system 32, such as a consumer storage system 32-1 or a large-scale storage system 32-2, and a lower-level control device 31, such as a consumer lower-level control device 31-1 or a large-scale facility lower-level control device 31-2. A system that includes the storage system 32 and the lower-level control device 31 is also referred to as a charging/discharging system 30.

The power system 1 provides ancillary services (adjustment power services) to the power transmission and distribution company by integrally controlling the charging and discharging of the multiple power storage systems 32. The ancillary services referred to here are services for maintaining power quality.
The ancillary services provided by the power system 1 are not limited to specific services. For example, the power system 1 may provide a frequency adjustment service for the power grid 920, such as load frequency control (LFC) or Δf control. Alternatively, the power system 1 may provide a load adjustment service, such as demand response.
Moreover, the power system 1 may be configured to provide a plurality of services.

Both LFC and Δf control are controls for aligning the system frequency with a reference frequency. In LFC and Δf control, for example, charging and discharging are performed in a cycle of about several seconds in LFC, while charging and discharging are performed in a cycle of about seconds or less in Δf control, so LFC has a relatively longer cycle and a relatively slower response speed. In demand response, the power consumption of electrical equipment (= power demand) is adjusted so that the power demand is increased or decreased by the requested amount.
The term "charging and discharging" used here may refer to either charging or discharging, or may refer to alternating charging and discharging.

The upper control system 10 determines the charge/discharge amount (charge/discharge command value) for each storage system group in response to the service implementation request, and instructs the intermediate control system 20 to implement charging/discharging for each storage system group. In particular, the upper control system 10 acquires a service implementation request that includes information on the charge/discharge request amount and information on the required accuracy, or the upper control system 10 itself determines the charge/discharge request amount and the required accuracy, and determines the charge/discharge amount for each storage system group so as to satisfy the required accuracy.

The units of charge and discharge amounts here may be units of power (e.g., watts (W) or kilowatts (kW)) or units of electrical energy (e.g., watt-hours (Wh) or kilowatt-hours (kWh)). In addition, the units of charge and discharge amounts may be converted within the power system 1, such as the upper control system 10 or the intermediate control system 20.

The units of the charge/discharge amount can be converted to units of electric energy by multiplying the charge/discharge amount expressed in units of electric power by a predetermined unit of time. Also, the units of the charge/discharge amount can be converted to units of electric energy by dividing the charge/discharge amount expressed in units of electric energy by a predetermined unit of time.

The energy storage system group here refers to each group of energy storage systems 32 divided according to the rated value of the charge/discharge amount and the accuracy of the charge/discharge control. The accuracy of the charge/discharge control here is an index of how much the output of the energy storage system deviates from the control command value. The accuracy of the charge/discharge control may be the ratio of the magnitude of the error in the output relative to the control command value divided by the magnitude of the control command value (|output-control command value|/|control command value|). The ratio of the magnitude of the error in the output relative to the control command value divided by the magnitude of the control command value is also referred to as the error ratio.

By grouping the energy storage systems 32 into energy storage system groups, the upper control system 10 only needs to determine the charge/discharge amount for each energy storage system group, making processing simpler than when the charge/discharge amount for each energy storage system 32 is determined directly.

In the following, an example will be described in which all the power storage systems 32 included in the same power storage system group have the same rated value of the charge/discharge amount and the same accuracy of the charge/discharge control.
However, for all the energy storage systems 32 included in the same energy storage system group, it is sufficient that the differences in the rated values of the charge/discharge amounts and the differences in the accuracy of the charge/discharge control are similar enough to be negligible, and they do not need to be exactly the same.

The upper control system 10 may determine the amount of charge and discharge for each storage system 32 so that all storage system groups are caused to charge and discharge for the provision of the service. Alternatively, the upper control system 10 may determine the amount of charge and discharge for each storage system 32 so that only some of the storage system groups are caused to charge and discharge for the provision of the service.

The upper control device 11 determines the charge/discharge amount for each power storage system group by calculation. The upper control device 11 notifies the middle-level control device 21 of the determined charge/discharge amount and transmits a command to the middle-level control device 21 to instruct charging/discharging. The upper control device 11 may also directly notify a specific charging/discharging system 30 of the determined charge/discharge amount and transmit a command to the lower control device 31 to instruct charging/discharging. The upper control device 11 may be configured using a computer such as a workstation or a personal computer (PC).
The upper control device 11 corresponds to an example of a control device.

The gateway device 91 mediates communication between each of the upper control device 11, the middle control device 21, and the lower control device 31 and the communication network 910. As the gateway device 91, a gateway device with different specifications may be used depending on the specifications of the connected equipment.

The intermediate control system 20 acquires charge/discharge command values for each storage system group, determines charge/discharge command values for each storage system 32 included in the storage system group, and instructs each corresponding charge/discharge system 30 to perform charging/discharging. By determining charge/discharge command values for each storage system 32 so as to satisfy the charge/discharge command values for each storage system group notified by the upper control system 10, the intermediate control system 20 can cause each storage system 32 to perform charging/discharging so as to satisfy the required accuracy notified in the service implementation request.

For example, the intermediate control system 20 may divide the charge/discharge command value for each storage system group notified by the upper control system 10 by the number of storage systems 32 included in the storage system group, and assign the charge/discharge command value evenly to each of the storage systems 32.
Alternatively, a chargeable/dischargeable amount available for ancillary services may be set for each power storage system 32 (i.e., for each charge/discharge system 30), and the intermediate control system 20 may assign a charge/discharge command value for each power storage system group to each power storage system 32 within the range of the chargeable/dischargeable amount. For example, the rated value of the charge/discharge amount of the power storage system 32 used by the power consumer may be divided into a chargeable/dischargeable amount for ancillary services and a chargeable/dischargeable amount for energy management services. Then, the power storage system 32 may simultaneously perform charging/discharging for the ancillary services and charging/discharging for the energy management services.

The energy management service provided by the charging/discharging system 30 is not limited to a specific service. For example, the charging/discharging system 30 may implement peak shift, peak shaving, or power selling, or a combination of these.

Peak shifting is a service that reduces electricity bills by charging an energy storage system during times when electricity rates are relatively low and covering the power consumption of devices during times when electricity rates are relatively high (discharging the energy storage system).
Peak shaving is a service that sets a threshold power and, if power consumption exceeds the threshold power, discharges the battery system to cut peak demand. For example, if electricity rates are set in stages according to maximum power, peak shaving can reduce the maximum power and thus reduce electricity rates.
Selling electricity is a service in which electricity consumers provide electricity to the commercial power grid (reverse power flow). Electricity consumers receive payment according to the amount of electricity they provide.

The middle-level control device 21 determines, by calculation, a charge/discharge command value for each power storage system 32. The middle-level control device 21 notifies the lower-level control device 31 of the determined charge/discharge command value and transmits a command to instruct charging/discharging to the lower-level control device 31. The middle-level control device 21 may be configured using a computer such as a workstation or a personal computer.
The intermediate control device 21 corresponds to an example of a control device.

The configuration in the power system 1 for determining charge/discharge command values for each of the energy storage systems 32 in response to a service implementation request and instructing charging/discharging is not limited to a specific configuration, but can be various configurations that can determine charge/discharge command values for each of the energy storage systems 32 taking into account the required accuracy.

In the example of Figure 1, the configuration for determining charge/discharge command values for each of the power storage systems 32 in response to a service implementation request in the power system 1 and instructing charging/discharging is configured using a high-level control device 11 and a middle-level control device 21. This configuration can be understood as a two-tier configuration, with a tier of the high-level control device 11 and a tier of the middle-level control device 21.

As in the example of Figure 1, when a higher-level control device 11 and a middle-level control device 21 are used, the higher-level control device 11 may be configured as a device used by an aggregation coordinator (AC), and the middle-level control device 21 may be configured as a device used by a resource aggregator (RA).

In this case, the resource aggregator may perform integrated control of the power storage system 32 using the intermediate control device 21 to provide an energy service to the aggregation coordinator. The aggregation coordinator may further integrate the energy services provided by the resource aggregator using the upper control device 11 to provide an ancillary service in response to a service implementation request from the power transmission and distribution company.
A plurality of middle-level control devices 21 may be provided for one upper control device 11. For example, a middle-level control device 21 may be provided for each power storage system group such that the power storage system group and the middle-level control device 21 are in one-to-one correspondence with each other.

The upper control device 11 may also be installed in the central load dispatching center of the electricity transmission and distribution business operator. In this case, the electricity transmission and distribution business operator may use the upper control device 11 to determine the charge/discharge requirement amount for each energy storage system group, and transmit a command to notify the charge/discharge requirement amount for each energy storage system group and request the implementation of charging/discharging as a service implementation request.

Alternatively, the upper level control device 11 and the middle level control device 21 may be configured as a single device. In this case, the configuration can be understood as a one-layer configuration in which the upper level control device 11 and the middle level control device 21 are integrated into one device.
Alternatively, the power system 1 may have a configuration with three or more hierarchical layers for determining charge/discharge command values for each of the power storage systems 32 in response to a service implementation request and instructing charging/discharging. For example, the power storage systems 32 may be grouped into a plurality of lower groups, and the lower groups may be further grouped into a plurality of upper groups, so that the power storage system group has two or more hierarchical layers. A higher-level control device 11 may be provided for each hierarchical layer of the power storage system group.

The consumer-installed system 30-1 is a system used by an electric power consumer. In FIG. 1, the consumer-installed system 30-1 and the large-scale charging/discharging system 30-2 are shown as examples of the charging/discharging system 30 that performs charging/discharging for ancillary services. However, the configuration of the charging/discharging system 30 is not limited to a specific configuration. The charging/discharging system 30 may have various configurations that include a power storage system 32 and can perform charging/discharging for providing ancillary services in accordance with charging/discharging instructions from the intermediate control system 20. Each charging/discharging system 30 may have a different configuration.
The customer-installed system 30-1 is not limited to a system for a specific purpose. For example, the customer-installed system 30-1 may be a system for a home (individual residence), a system for a company office (building), a system for a factory, or a system for a store.

The consumer low-level control device 31-1 controls the devices of the consumer installed system 30-1 to adjust the supply and demand of power in the consumer installed system 30-1. In particular, the consumer low-level control device 31-1 controls the consumer storage system 32-1 in response to a request from the mid-level control system 20 to charge and discharge the power in accordance with a charge/discharge command value. As described above, the consumer low-level control device 31-1 corresponds to an example of the low-level control device 31. Also, as described above, the consumer low-level control device 31-1 may cause the consumer storage system 32-1 to charge and discharge the power for the energy management service in addition to the charging and discharging for the provision of ancillary services requested by the mid-level control device 21.
The lower level controller 31, such as the consumer lower level controller 31-1 or the large facility lower level controller 31-2, may be configured using a computer, such as a workstation or a personal computer.

The consumer power storage system 32-1 charges and discharges in accordance with the control of the consumer lower-level control device 31-1. As a result, the consumer power storage system 32-1 performs charging and discharging for the provision of ancillary services requested by the intermediate-level control device 21. As described above, the consumer power storage system 32-1 may be configured to charge and discharge for energy management services in addition to charging and discharging for the provision of ancillary services in accordance with the control of the consumer lower-level control device 31-1.

The distribution board 41 is provided at the interconnection point between the power grid 920 and the customer installed system 30-1.
The customer-premises power wiring 43 is a power system within the customer-premises installed system 30-1, which is configured using power lines laid within the customer-premises installed system 30-1.

The consumer load 44 is a power consuming device provided in the consumer installation system 30-1. The consumer load 44 is not limited to a specific type of device, and may be various devices that consume power. The consumer load 44 may be configured to include one device, or may be configured to include multiple devices.
The solar power generation facility 47 includes, for example, a solar cell and a power conditioning system. The solar cell receives sunlight and generates power, and the power conditioning system converts the DC power generated by the solar cell into AC power and outputs it.

The large-scale charging/discharging system 30-2 charges and discharges between the power grid 920 and the large-scale power storage system 32-2. The large-scale charging/discharging system 30-2 may be a system provided exclusively for the purpose of maintaining the power quality of the power grid 920. Alternatively, the large-scale charging/discharging system 30-2 may be used for purposes other than maintaining the power quality of the power grid 920, such as being part of a factory facility.

The low-level controller for large equipment 31-2 controls the charging and discharging of the large-scale battery system 32-2 in accordance with commands from the intermediate controller 21.
The large-scale power storage system 32-2 performs charging and discharging under the control of the large-scale equipment lower-level control device 31-2. The large-scale power storage system 32-2 is shown as an example in which the power system 1 is equipped with a power storage system 32 having different specifications. The rated charge and discharge amount of the large-scale power storage system 32-2 is greater than the rated charge and discharge amount of the consumer power storage system 32-1.

Figure 2 is a schematic block diagram showing an example of the functional configuration of the upper control device 11. In the configuration shown in Figure 2, the upper control device 11 includes a first communication unit 110, a first memory unit 180, and a first control unit 190. The first control unit 190 includes a request amount information acquisition unit 191, a group command value calculation unit 192, and a group command value transmission processing unit 193.

The first communication unit 110 communicates with other devices via the gateway device 91 and the communication network 910. For example, the first communication unit 110 may receive a service implementation request from a power transmission and distribution company. The first communication unit 110 also transmits a charge/discharge command for the power storage system group to the intermediate control device 21.
The charge/discharge command transmitted by the first communication unit 110 indicates a charge/discharge command value for the power storage system group. When the upper control device 11 determines to cause only some of the power storage systems 32 in the power storage system group to perform charging/discharging, the charge/discharge command transmitted by the first communication unit 110 may indicate the number of the power storage systems 32 to be charged/discharged, in addition to the charge/discharge command value.
The first communication unit 110 corresponds to an example of a command value transmitting means.

The first memory unit 180 is configured using a memory device provided in the upper level control device 11, and stores various types of information.
The first control unit 190 controls each part of the upper level control device 11 to perform various processes. The functions of the first control unit 190 may be performed by a CPU (Central Processing Unit) included in the upper level control device 11 reading out a program from the first storage unit 180 and executing the program.

The request amount information acquisition unit 191 acquires a service implementation request. For example, the request amount information acquisition unit 191 may read out service implementation request information including information on the charge/discharge request amount and information on the allowable accuracy from the signal received by the first communication unit 110. Alternatively, in a case where the upper control device 11 is installed in a central load control center of a power transmission and distribution company, the upper control device 11 may accept input of a service implementation request by user operation using input devices such as a keyboard and a mouse provided on the upper control device 11.

The group command value calculation unit 192 calculates a charge/discharge command value based on the accuracy of charge/discharge control of the power storage system. In particular, the group command value calculation unit 192 calculates a charge/discharge command value for the power storage system group based on the accuracy of charge/discharge control of the power storage system group.
Specifically, the group command value calculation unit 192 calculates a charge/discharge amount lower limit value so that the ratio of the error expected value to the charge/discharge amount of the storage system group becomes the upper limit of the allowable error ratio based on the error expected value in the charging/discharging of the storage system group and the upper limit of the allowable error ratio for the charge/discharge request amount in the service implementation request.

The allowable error rate upper limit value here indicates the maximum value (upper limit value) of the error allowable for the charge/discharge request amount in the service execution request in the form of an error rate.
The charge/discharge request amount in the service execution request is also referred to as a service request amount. The allowable error rate upper limit value indicates the required accuracy for charge/discharge control as a rate of the maximum allowable error for the charge/discharge request amount in the service execution request.

The estimated error value in charging and discharging of the power storage system group is calculated as the sum of the estimated error values in charging and discharging of the power storage systems 32 included in the power storage system group.
Here, the error included in the charge/discharge control of the power storage system, i.e., the error of the charge/discharge amount of the power storage system, often depends on the rated output of the power conditioning system of the power storage system. The rated output of the power conditioning system of the power storage system is also called the rated value of the charge/discharge amount of the power storage system.
Furthermore, the accuracy of charge/discharge control of a power storage system becomes higher as the scale of the power storage system increases, and an error of about 5% to 1% of the rated charge/discharge amount is expected, for example.

Therefore, an estimated error value in charging and discharging the power storage system 32 may be obtained in advance for each type of power storage system 32 as a constant value of power or amount of power. This estimated error value depends on, for example, the rated value of the charge and discharge amount of the power storage system 32, and the larger the rated value, the smaller the ratio of the estimated error value to the rated value. In other words, the larger the rated value of the power storage system 32, the higher the accuracy of the charge and discharge control.

The group command value calculation unit 192 assigns charge/discharge command values to the power storage system groups so that the charge/discharge amounts of the power storage system groups are equal to or greater than the charge/discharge amount lower limit value of the power storage system group, or are 0. Assigning a charge/discharge command value of 0 to a power storage system group means that the power storage system group is not allowed to perform charging/discharging for ancillary services.
Group command value calculation unit 192 corresponds to an example of a command value calculation means.

The group command value transmission processing unit 193 controls the first communication unit 110 to transmit a charge/discharge command for the energy storage system group to the intermediate control device 21, or directly to a specified lower-level control device 31. This charge/discharge command includes information indicating the charge/discharge command value calculated by the group command value calculation unit 192.

Figure 3 is a schematic block diagram showing an example of the functional configuration of the mid-level control device 21. In the configuration shown in Figure 3, the mid-level control device 21 includes a second communication unit 210, a second memory unit 280, and a second control unit 290. The second control unit 290 includes a group command value acquisition unit 291, an individual command value calculation unit 292, and an individual command value transmission processing unit 293.

The second communication unit 210 communicates with other devices via the gateway device 91 and the communication network 910. For example, the second communication unit 210 receives a charge/discharge command for the power storage system group from the upper control device 11. The second communication unit 210 also transmits a charge/discharge command for the power storage system 32 to the lower control device 31 that controls the power storage system 32. In other words, the second communication unit 210 transmits a charge/discharge command for the power storage system 32 to the lower control device 31 of the charge/discharge system 30 that includes the power storage system 32.
The charge/discharge command transmitted by the second communication unit 210 indicates a charge/discharge command value for each power storage system 32 .
The second communication unit 210 corresponds to an example of a command value transmitting means.

The second memory unit 280 is configured using a memory device provided in the intermediate control device 21, and stores various information.
The second control unit 290 controls each unit of the middle-level control device 21 to perform various processes. The functions of the second control unit 290 may be performed by a CPU included in the middle-level control device 21 reading out a program from the second storage unit 280 and executing the program.

The group command value acquisition unit 291 acquires a charge/discharge command for the power storage system group. Specifically, the group command value acquisition unit 291 reads out charge/discharge command information including information on a charge/discharge command value for the power storage system group from a signal received by the second communication unit 210.
The individual command value calculation unit 292 assigns the charge/discharge command values for the power storage system group to the power storage systems 32 included in the power storage system group, and determines the charge/discharge command values for each of the power storage systems 32 .

As described above for the intermediate control system 20, the individual command value calculation unit 292 may divide the charge/discharge command value for the power storage system group by the number of power storage systems 32 included in the power storage system group to allocate the charge/discharge amount evenly to each of the power storage systems 32. Alternatively, the individual command value calculation unit 292 may allocate the charge/discharge amount for each power storage system group to each power storage system 32 within the range of the chargeable/dischargeable amount set for each power storage system 32.
The individual command value calculation unit 292 corresponds to an example of a command value calculation means.

The individual command value transmission processing unit 293 controls the second communication unit 210 to transmit a charge/discharge command for the energy storage system 32 to the lower control device 31. This charge/discharge command includes information indicating the charge/discharge command value calculated by the individual command value calculation unit 292.

Fig. 4 is a diagram showing a configuration example of a power storage system group. In the example of Fig. 4, as examples of the charge/discharge system 30, an A-type charge/discharge system 30A, a B-type charge/discharge system 30B, and a C-type charge/discharge system 30C are shown.
The A-type charge/discharge system 30A includes an A-type lower control device 31A and an A-type power storage system 32A. The B-type charge/discharge system 30B includes a B-type lower control device 31B and a B-type power storage system 32B. The C-type charge/discharge system 30C includes a C-type lower control device 31C and a C-type power storage system 32C.

The A-type lower control device 31A, the B-type lower control device 31B, and the C-type lower control device 31C are all examples of lower control devices 31. The A-type power storage system 32A, the B-type power storage system 32B, and the C-type power storage system 32C are all examples of power storage systems 32.

The A-type charging/discharging system 30A is included in the A-type power storage system group 50A. As a result, the A-type power storage system 32A is included in the A-type power storage system group 50A. The B-type charging/discharging system 30B is included in the B-type power storage system group 50B. As a result, the B-type power storage system 32B is included in the B-type power storage system group 50B. The C-type charging/discharging system 30C is included in the C-type power storage system group 50C. As a result, the C-type power storage system 32C is included in the C-type power storage system group 50C.
The power storage system group is also referred to as a power storage system group 50. The A-type power storage system group 50A, the B-type power storage system group 50B, and the C-type power storage system group 50C are all examples of the power storage system group 50.

Fig. 5 is a diagram showing an example of the power storage system 32 shown in Fig. 4. Fig. 5 shows, for each of the A-type power storage system 32A, the B-type power storage system 32B, and the C-type power storage system 32C shown in Fig. 4, a rated value of the charge/discharge amount, an error (estimated value) in the charge/discharge amount, a ratio of an error in the rated value of the charge/discharge amount, the number (quantity) of the power storage systems 32 included in the power storage system group, a rated value of the charge/discharge amount of the power storage system group, an error (estimated value) in the charge/discharge of the battery group, a charge/discharge amount for making the error 50%, and a charge/discharge amount for making the error 10%.
The rated value of the charge/discharge amount is indicated by a PCS rating. The PCS rating is the rated output of a power conditioning system of the power storage system. The PCS rating can be said to be the rated output of the power storage system 32.

The rated charge/discharge capacity of the A-type power storage system 32A is 5000 watts. The rated charge/discharge capacity of the B-type power storage system 32B is 10000 watts. The rated charge/discharge capacity of the C-type power storage system 32C is 250000 watts.
The error (estimated value) in charging and discharging the A-type power storage system 32A is 250 watts. The error (estimated value) in charging and discharging the B-type power storage system 32B is 250 watts. The error (estimated value) in charging and discharging the C-type power storage system 32C is 2500 watts.

In this way, the example in Figure 5 shows a case where a certain amount of error is expected regardless of the output of the power storage system 32. However, the error may vary depending on the output of the power storage system 32. If the output of the power storage system 32 is fixed, the error is fixed, and the ratio of the error to the output should be smaller as the output of the power storage system 32 is larger.

The percentage of error in the rated value of the charge/discharge amount is the error (estimated value) divided by the rated value of the charge/discharge amount. For example, in the case of the A-type power storage system 32A, the error of 250 watts is divided by the rated value of 5,000 watts to calculate 5%. Calculating similarly, the percentage of error in the rated value of the charge/discharge amount for the B-type power storage system 32B and the C-type power storage system 32C are 2.5% and 1%, respectively.

5, the A-type power storage system group 50A includes 1,000 A-type power storage systems 32A. The B-type power storage system group 50B includes 100 B-type power storage systems 32B. The C-type power storage system group 50C includes 10 C-type power storage systems 32C.
The rated value of the charge/discharge amount of the power storage system group is calculated as the sum of the rated values of the power storage systems 32 included in the power storage system group. For example, the rated value of the charge/discharge amount of the A-type power storage system group 50A is calculated as 5000 kilowatts by multiplying the rated value of the charge/discharge amount of the A-type power storage system 32A (5000 watts) by the number of A-type power storage systems 32A (1000). By similar calculation, the rated values of the charge/discharge amounts of the B-type power storage system group 50B and the C-type power storage system group 50C are calculated to be 1000 kilowatts and 2500 kilowatts, respectively.

The charge/discharge error of the storage system group is calculated as the sum of the charge/discharge errors of the storage systems 32 included in the storage system group. For example, the charge/discharge error of the A-type storage system group 50A is calculated as 250 kilowatts by multiplying the error of 250 watts during charging/discharging of the A-type storage system 32A by the number of A-type storage systems 32A, 1,000. Using a similar calculation, the charge/discharge errors of the B-type storage system group 50B and the C-type storage system group 50C are calculated to be 25 kilowatts and 25 kilowatts, respectively.

The charge/discharge amount for which the error is 50% is calculated by dividing the error by 50%. In other words, the charge/discharge amount for which the error is 50% is calculated by doubling the error.
For example, in order for the charge/discharge error of the A-type power storage system 32A to be 50%, the A-type power storage system 32A charges and discharges 500 watts, which is twice the error of 250 watts. If the charge/discharge amount of the A-type power storage system 32A is 500 watts or more, the error will be 50% or less.

Calculating similarly, in order for the charge/discharge error of the A-type power storage system group 50A to be 50%, the A-type power storage system group 50A would charge/discharge 500 kilowatts, which is twice the error of 250 kilowatts. If the charge/discharge amount of the A-type power storage system group 50A is 500 kilowatts or more, the error will be 50% or less.

In order for the charge/discharge error of the B-type power storage system 32B to be 50%, the B-type power storage system 32B charges and discharges 500 watts, which is twice the error of 250 watts. If the charge/discharge amount of the B-type power storage system 32B is 500 watts or more, the error will be 50% or less.
In order to make the charge/discharge error of the B type power storage system group 50B 50%, the B type power storage system group 50B performs charging/discharging of 50 kilowatts, which is twice the error of 25 kilowatts. If the charge/discharge amount of the B type power storage system group 50B is 50 kilowatts or more, the error will be 50% or less.

In order for the charge/discharge error of the C type power storage system 32C to be 50%, the C type power storage system 32C charges and discharges 5000 watts, which is twice the error of 2500 watts. If the charge/discharge amount of the C type power storage system 32C is 5000 watts or more, the error will be 50% or less.
In order to make the charge/discharge error of the C type power storage system group 50C 50%, the C type power storage system group 50C performs charging/discharging of 50 kilowatts, which is twice the error of 25 kilowatts. If the charge/discharge amount of the C type power storage system group 50C is 50 kilowatts or more, the error will be 50% or less.
The charge/discharge amount for making the error 50% corresponds to an example of the charge/discharge amount lower limit when the upper limit of the allowable error rate is set to 50%. The charge/discharge amount lower limit is the lower limit (minimum value) of the charge/discharge amount required to make the error equal to or less than the upper limit of the allowable error rate. The charge/discharge amount lower limit is calculated by dividing the expected error value (expected error) by the upper limit of the allowable error rate.

The charge/discharge amount for which the error is 10% is calculated by dividing the error by 10%. In other words, the charge/discharge amount for which the error is 10% is calculated by multiplying the error by 10.
For example, in order for the charge/discharge error of the A-type power storage system 32A to be 10%, the A-type power storage system 32A charges and discharges at 2500 watts, which is 10 times the error of 250 watts. If the charge/discharge amount of the A-type power storage system 32A is 2500 watts or more, the error will be 10% or less.

Calculating similarly, in order for the charge/discharge error of the A-type power storage system group 50A to be 10%, the A-type power storage system group 50A would charge/discharge 2,500 kilowatts, which is 10 times the error of 250 kilowatts. If the charge/discharge amount of the A-type power storage system group 50A is 2,500 kilowatts or more, the error will be 10% or less.

In order for the charge/discharge error of the B-type power storage system 32B to be 10%, the B-type power storage system 32B charges and discharges at 2500 watts, which is 10 times the error of 250 watts. If the charge/discharge amount of the B-type power storage system 32B is 2500 watts or more, the error will be 10% or less.
In order to make the charge/discharge error of the B type power storage system group 50B 10%, the B type power storage system group 50B performs charging/discharging of 250 kilowatts, which is 10 times the error of 25 kilowatts. If the charge/discharge amount of the B type power storage system group 50B is 250 kilowatts or more, the error will be 10% or less.

In order for the charge/discharge error of the C type power storage system 32C to be 10%, the C type power storage system 32C charges and discharges at 25,000 watts, which is 10 times the error of 2,500 watts. If the charge/discharge amount of the C type power storage system 32C is 25,000 watts or more, the error will be 10% or less.
In order to make the charge/discharge error of the C type power storage system group 50C 10%, the C type power storage system group 50C performs charging/discharging of 250 kilowatts, which is 10 times the error of 25 kilowatts. If the charge/discharge amount of the C type power storage system group 50C is 250 kilowatts or more, the error will be 10% or less.
The charge/discharge amount for which the error is 10% corresponds to an example of the lower limit of the charge/discharge amount when the upper limit of the allowable error rate is set to 10%.

Fig. 6 is a diagram showing a first example of control of charging and discharging of the power storage system 32. Fig. 6 shows a first example of the configuration example of the power system 1 described with reference to Figs. 4 and 5, in which the power system 1 performs LFC.
In the example of Fig. 6, the total of the rated values of the charge and discharge amounts of the A-type power storage system group 50A, the B-type power storage system group 50B, and the C-type power storage system group 50C is 5000 + 1000 + 2500 = 8500 kilowatts. In the example of Fig. 6, a case is considered in which the energy management service is not performed and the entire charge and discharge amount of 8500 kilowatts can be used for LFC. The power system 1 performs charging and discharging for LFC within the range from 0 to 8500 kilowatts.
This 8,500 kilowatts is normalized as a maximum value of 100% and expressed as "1," and the minimum increment of control is set to 1%, or 85 kilowatts. In normalized values, 1% is expressed as "0.01."

For example, when the LFC signal from the central load dispatching center is 0.01, this LFC signal indicates a charge/discharge request of 8500 x 0.01 = 85 kilowatts. Also, the accuracy of the charge/discharge request is within an error of 50% for the service request amount.
The upper control device 11 determines the allocation of charge/discharge command values to each of the power storage system groups 50 so as to allocate to the power storage system group 50 a charge/discharge amount equal to or greater than the allocation amount to the power storage system group 50 when the error is 50% as shown in Fig. 5. In the example of Fig. 6, the upper control device 11 allocates the entire charge/discharge amount of 85 kilowatts to the B-type power storage system group 50B.

The upper control device 11 calculates a value of "0.085" indicating 85 kilowatts when the rated value of the charge/discharge amount of the B-type energy storage system group 50B, 1000 kilowatts, is normalized as "1", and transmits 0.085 to the middle control device 21 as a conversion signal for the B-type energy storage system group 50B. The conversion signal here is a signal converted from the LFC signal. The conversion signal is an example of a charge/discharge command value.

The intermediate control device 21 transmits (transfers) the conversion signal from the upper control device 11 to each of the B-type charging/discharging systems 30B included in the B-type storage system group 50B. On the other hand, the intermediate control device 21 does not transmit a charge/discharge command value to each of the A-type charging/discharging systems 30A included in the A-type storage system group 50A and the C-type charging/discharging systems 30C included in the C-type storage system group 50C.

The conversion signal 0.085 sent by the intermediate control device 21 to the B-type charge/discharge system 30B indicates 850 watts when the rated value of the charge/discharge amount of the B-type power storage system 32B, 10,000 watts, is standardized as "1." Each of the 100 B-type power storage systems 32B charges and discharges at 850 watts, so that the B-type power storage system group 50B as a whole charges and discharges at 85 kilowatts.

In this way, by using a signal indicating the ratio of the charging/discharging amount to the rated value as the conversion signal, the intermediate control device 21 can transmit (transfer) the conversion signal from the upper control device 11 as is to each of the B type charging/discharging systems 30B.
Each of the B type charging/discharging systems 30B performs charging/discharging of 850 watts in accordance with the conversion signal.
6, the charge/discharge power for LFC is 85 kW, while the error is 25 kW. The ratio of the error to the charge/discharge power is 25/85≈29%, which satisfies the condition of being within 50%.

Fig. 7 is a diagram showing a second example of control of charging and discharging of the power storage system 32. Fig. 7 shows a second example of the configuration example of the power system 1 described with reference to Figs. 4 and 5, in which the power system 1 performs LFC.
7, the energy management service is not performed, and the entire charge/discharge capacity of 8,500 kW can be used for LFC. The power system 1 performs charge/discharge for LFC within the range of 0 to 8,500 kW.
This 8,500 kilowatts is normalized as a maximum value of 100% and expressed as "1," and the minimum increment of control is set to 1%, or 85 kilowatts. In normalized values, 1% is expressed as "0.01."

In the example of Fig. 7, the LFC signal from the central load dispatching center is 0.16, which indicates a charge/discharge request of 8500 x 0.16 = 1360 kilowatts. The accuracy of the charge/discharge request is within an error of 50% for the service request amount.
7, the charge/discharge request amount is equal to or more than 500 kilowatts required for keeping the error within 50% in the A-type power storage system group 50A. Therefore, it is possible to allocate a charge/discharge command value to the A-type power storage system group 50A.

Therefore, in the example of Figure 7, the upper control device 11 assigns 1,000 kilowatts of charging and discharging to the A-type energy storage system group 50A, 180 kilowatts of charging and discharging to the B-type energy storage system group 50B, and 180 kilowatts of charging and discharging to the C-type energy storage system group 50C.

6, the upper control device 11 assigns a charge/discharge command value only to the B-type storage system group 50B, whereas in the example of FIG. 7, the upper control device 11 assigns a charge/discharge command value to each of the A-type storage system group 50A, the B-type storage system group 50B, and the C-type storage system group 50C. In this respect, the example of FIG. 7 can reduce the burden on the B-type charging/discharging system 30B included in the B-type storage system group 50B. In addition, in the example of FIG. 7, the A-type charging/discharging system 30A included in the A-type storage system group 50A and the C-type charging/discharging system 30C included in the C-type storage system group 50C can have equal opportunities to participate in the ancillary service.

The upper control device 11 calculates the value "0.2" which indicates 1000 kilowatts when the rated value of the charge/discharge capacity of the A-type energy storage system group 50A, 5000 kilowatts, is standardized as "1", and transmits 0.2 to the intermediate control device 21 as a conversion signal for the A-type energy storage system group 50A.

In addition, the upper control device 11 calculates a value of "0.18" indicating 180 kilowatts when the rated value of the charge/discharge capacity of the B-type storage system group 50B, 1000 kilowatts, is standardized as "1", and transmits 0.18 to the intermediate control device 21 as a conversion signal for the B-type storage system group 50B.

In addition, the upper control device 11 calculates a value of "0.072" indicating 180 kilowatts when the rated value of the charge/discharge capacity of the C-type storage system group 50C, 2,500 kilowatts, is standardized as "1", and transmits 0.072 to the intermediate control device 21 as a conversion signal for the C-type storage system group 50C.

The intermediate control device 21 transmits (transfers) a conversion signal for the A-type power storage system group 50A from the upper control device 11 to each of the A-type charge/discharge systems 30A included in the A-type power storage system group 50A. The conversion signal 0.2 transmitted by the intermediate control device 21 to the A-type power storage system 30A indicates 1000 watts when the rated value of the charge/discharge amount of the A-type power storage system 32A, 5000 watts, is standardized as "1". Each of the 1000 A-type power storage systems 32A charges and discharges 1000 watts, so that the A-type power storage system group 50A as a whole performs 1000 charges and discharges.

In addition, the intermediate control device 21 transmits (transfers) the conversion signal from the upper control device 11 to each of the B-type charge/discharge systems 30B included in the B-type storage system group 50B. The conversion signal 0.18 transmitted by the intermediate control device 21 to the B-type charge/discharge system 30B indicates 1,800 watts when the rated value of the charge/discharge amount of the B-type storage system 32B, 10,000 watts, is standardized as "1". Each of the 100 B-type storage systems 32B charges and discharges at 1,800 watts, so that the B-type storage system group 50B as a whole charges and discharges at 180 kilowatts.

In addition, the middle level control device 21 transmits (transfers) the conversion signal from the upper level control device 11 to each of the C type charge/discharge systems 30C included in the C type storage system group 50C. The conversion signal 0.072 transmitted by the middle level control device 21 to the C type charge/discharge system 30C indicates 18,000 watts when the rated value of the charge/discharge amount of the C type storage system 32C, 250,000 watts, is standardized as "1". Each of the ten C type storage systems 32C charges and discharges at 18,000 watts, so that the C type storage system group 50C as a whole charges and discharges at 180 kilowatts.

Each of the A-type charging/discharging systems 30A performs charging/discharging at 1000 watts in accordance with the conversion signal. Each of the B-type charging/discharging systems 30B performs charging/discharging at 1800 watts in accordance with the conversion signal. Each of the C-type charging/discharging systems 30C performs charging/discharging at 18000 watts in accordance with the conversion signal.
7, the charge/discharge power for LFC is 1360 kW, while the error is 250+25+25=300 kW. The ratio of the error to the charge/discharge power is 300/1360≈22%, which satisfies the condition of being within 50%.

Fig. 8 is a diagram showing a third example of control of charging and discharging of the power storage system 32. Fig. 8 shows a third example of the configuration example of the power system 1 described with reference to Figs. 4 and 5, in which the power system 1 performs LFC.
8, the energy management service is not performed, and the entire charge/discharge capacity of 8,500 kW can be used for LFC. The power system 1 performs LFC within the range of 0 to 8,500 kW.
This 8,500 kilowatts is normalized as a maximum value of 100% and expressed as "1," and the minimum increment of control is set to 1%, or 85 kilowatts. In normalized values, 1% is expressed as "0.01."

8, the LFC signal from the central load dispatching center is 0.16, and this LFC signal indicates a charge/discharge request of 8500×0.16=1360 kW. The accuracy of the charge/discharge request is within an error of 50% for the service request amount.
On the other hand, in the example of Fig. 8, the allocation of charge/discharge amounts to the power storage system group 50 differs from that in the example of Fig. 7. In Fig. 8, the upper control device 11 allocates 660 kW of charge/discharge to the B-type power storage system group 50B, and allocates 700 kW of charge/discharge to the C-type power storage system group 50C.

The upper control device 11 calculates the value "0.66" which indicates 660 kilowatts when the rated value of the charge/discharge capacity of the B-type energy storage system group 50B, 1000 kilowatts, is standardized as "1", and transmits 0.66 to the intermediate control device 21 as a conversion signal for the B-type energy storage system group 50B.

In addition, the upper control device 11 calculates a value of "0.28" indicating 700 kilowatts when the rated value of the charge/discharge capacity of the C-type storage system group 50C, 2,500 kilowatts, is standardized as "1", and transmits 0.28 to the intermediate control device 21 as a conversion signal for the C-type storage system group 50C.

The intermediate control device 21 transmits (transfers) the conversion signal from the upper control device 11 to each of the B-type charge/discharge systems 30B included in the B-type storage system group 50B. The conversion signal 0.66 transmitted by the intermediate control device 21 to the B-type charge/discharge system 30B indicates 6,600 watts when the rated value of the charge/discharge amount of the B-type storage system 32B, 10,000 watts, is standardized as "1." Each of the 100 B-type storage systems 32B charges and discharges at 6,600 watts, so that the B-type storage system group 50B as a whole charges and discharges at 660 kilowatts.

Furthermore, the middle level control device 21 transmits (transfers) the conversion signal from the upper level control device 11 to each of the C type charging/discharging systems 30C included in the C type power storage system group 50C. The conversion signal 0.28 transmitted by the middle level control device 21 to the C type power storage system 30C indicates 70,000 watts when the rated value of the charge/discharge amount of the C type power storage system 32C, 250,000 watts, is standardized as "1". Each of the ten C type power storage systems 32C charges and discharges at 70,000 watts, so that the C type power storage system group 50C as a whole charges and discharges at 700 kilowatts.
On the other hand, the intermediate control device 21 does not transmit a charge/discharge command value to each of the A-type charge/discharge systems 30A included in the A-type power storage system group 50A.

Each of the B-type charging/discharging systems 30B charges/discharges at 6,600 watts in accordance with the conversion signal. Each of the C-type charging/discharging systems 30C charges/discharges at 70,000 watts in accordance with the conversion signal.

In the example of Fig. 8, the charge/discharge power for LFC is 1360 kW, while the error is 25 + 25 = 50 kW. The ratio of the error to the charge/discharge power is 50/1360 ≈ 4%, which satisfies the condition of being within 50%.
In addition, the charge/discharge power for LFC is 1,360 kW in both the examples of Fig. 7 and Fig. 8. Meanwhile, the error is about 22% in the example of Fig. 7, whereas the error is about 4% in the example of Fig. 8, which is a smaller error.

In this way, by the upper level control device 11 selecting the power storage system group 50 to which the charge/discharge command value is assigned, the error may be reduced.
For example, when the required accuracy of charge/discharge control varies within a range from within an error of 50% to within an error of 10%, the upper control device 11 may switch the power storage system group 50 to which the charge/discharge command value is assigned according to the allowable error. For example, when the allowable error is small, the upper control device 11 may select the power storage system group 50 so as to reduce the error and assign the charge/discharge command value. On the other hand, when the allowable error is large, the upper control device 11 may select the power storage system group 50 so as to equalize the opportunity to participate in the service and assign the charge/discharge command value.
The upper control device 11 may use at least one of the history of charging/discharging time, the history of charging/discharging power amount, or the history of the number of times participation in the service through charging/discharging for each energy storage system group 50 as an index value for the opportunity to participate in the service.

Fig. 9 is a diagram showing a fourth example of control of charging and discharging of the power storage system 32. Fig. 9 shows a fourth example of the configuration example of the power system 1 described with reference to Figs. 4 and 5, in which the power system 1 performs LFC.
FIG. 9 shows an example in which an A-type charge/discharge system 30A performs LFC and energy management services simultaneously.

Here, it is assumed that the target minimum value of the error is set to 10% of the charge/discharge amount. The target minimum value of the error expressed as a ratio to the charge/discharge amount is also referred to as an error ratio lower limit value.
As shown in Fig. 5, in order to achieve an error of 10%, the A-type power storage system group 50A needs to perform charging and discharging of 2500 kilowatts or more. The B-type power storage system group 50B needs to perform charging and discharging of 250 kilowatts or more. The C-type power storage system group 50C also needs to perform charging and discharging of 250 kilowatts or more.

In order to secure these charge and discharge amounts, charge and discharge amounts equal to or greater than the target minimum error value are allocated as charge and discharge amounts for LFC. In the example of FIG. 9, of the rated charge and discharge amount of 5000 kilowatts of the A-type storage system group 50A, 3500 kilowatts is allocated to LFC, and 1500 kilowatts is allocated to the energy management service. Also, of the rated charge and discharge amount of 1000 kilowatts of the B-type storage system group 50B, 500 kilowatts is allocated to LFC, and 500 kilowatts is allocated to the energy management service. Of the rated charge and discharge amount of 2500 kilowatts of the C-type storage system group 50C, 2000 kilowatts is allocated to LFC, and 500 kilowatts is allocated to the energy management service.

The total amount of charge and discharge allocated to LFC, 3500+500+2000=6000 kW, can be used for LFC. The power system 1 performs charging and discharging for LFC within the range of 0 to 6000 kW.
This 6000 kilowatts is normalized as a maximum value of 100% and expressed as "1," and the minimum increment of control is set to 1%, or 60 kilowatts. In normalized values, 1% is expressed as "0.01."

In the example of Fig. 9, the LFC signal from the central load dispatching center is 0.01, which indicates a charge/discharge request of 6000 x 0.01 = 60 kilowatts. The accuracy of the charge/discharge request is within an error of 50% for the service request amount.
In the example of FIG. 9, the upper control device 11 allocates the entire charge/discharge capacity of 60 kilowatts to the C type power storage system group 50C.

The upper control device 11 calculates the value "0.03" which indicates 60 kilowatts when the rated charge/discharge capacity of the C-type storage system group 50C, 2,500 kilowatts, is standardized as "1", and transmits 0.03 to the intermediate control device 21 as a conversion signal for the C-type storage system group 50C.

The intermediate control device 21 transmits (transfers) the conversion signal from the upper control device 11 to each of the C-type charging/discharging systems 30C included in the C-type storage system group 50C. On the other hand, the intermediate control device 21 does not transmit a charge/discharge command value to each of the A-type charging/discharging systems 30A included in the A-type storage system group 50A and the B-type charging/discharging systems 30B included in the B-type storage system group 50B.

The conversion signal 0.03 transmitted by the intermediate control device 21 to the C type charge/discharge system 30C indicates 6000 watts when the rated value of the charge/discharge amount of the C type power storage system 32C, 250,000 watts, is normalized as "1." Each of the ten C type power storage systems 32C charges and discharges at 6000 watts, so that the C type power storage system group 50C as a whole charges and discharges at 60 kilowatts.
Each of the C type charging/discharging systems 30C performs charging/discharging of 6000 watts in accordance with the conversion signal.

9, the charge/discharge power for LFC is 60 kW, while the error is 25 kW. The ratio of the error to the charge/discharge power is 25/60≈42%, which satisfies the condition of being within 50%.
If the charge/discharge request amount in the service execution request is large, the rate of error in the charge/discharge power becomes smaller, and a method of allocating charge/discharge command values to the power storage system group 50 can be selected.

For example, when the LFC signal is 0.16, the charge/discharge required amount is 6000 x 0.16 = 960 kilowatts. In this case, if the upper control device 11 assigns charge/discharge command values only to the B-type power storage system group 50B, the error rate for charge/discharge power will be 25/960 ≒ 3%. Therefore, it is also possible to meet a request to temporarily reduce the error rate for discharge power to 10% or less.

On the other hand, when the allowable error remains at 50%, the upper control device 11 may assign a charge/discharge command value to the A-type power storage system group 50A or the C-type power storage system group 50C, or both, in addition to or instead of the B-type power storage system group 50B. This allows the upper control device 11 to reduce the burden on the B-type power storage system 30B included in the B-type power storage system group 50B. The upper control device 11 can also equalize the opportunity for the A-type power storage system 30A included in the A-type power storage system group 50A and the C-type power storage system 30C included in the C-type power storage system group 50C to participate in the ancillary service.

In addition, by setting a target for the minimum error, the required value for the ratio of error to the charge/discharge power can be changed, allowing for flexible operation. For example, as described above, when the allowable error is small, the upper control device 11 may select the storage system group 50 so as to reduce the error and assign the charge/discharge command value. On the other hand, when the allowable error is large, the upper control device 11 may select the storage system group 50 so as to equalize the opportunity to participate in the service and assign the charge/discharge command value.

In addition, when control precision is required for charging and discharging for energy management services, the lower control device 31 may set a lower limit value for the charging and discharging power so that the error ratio for the charging and discharging power is below an allowable value.

As described above, the upper level control device 11 may determine the allocation of charge/discharge command values to the power storage system group 50 so as to equalize the opportunity for the charge/discharge systems 30 to participate in the ancillary service.
For example, the upper control device 11 may use at least one of the history of charge/discharge implementation time, the history of charge/discharge power amount, and the history of the number of times participation in the service through charge/discharge implementation for each power storage system group 50 as an index value of the opportunity to participate in the service. Then, the upper control device 11 may preferentially assign a charge/discharge command value to a power storage system group 50 that is evaluated as having a low opportunity to participate in the service, and allow the power storage system group 50 to participate in the service.

On the other hand, in services where control accuracy is important, such as frequency adjustment services, the evaluation of a storage system 32 with high control accuracy may be increased. For example, the incentive for a storage system 32 with high control accuracy may be relatively high, and the incentive for a storage system 32 with low control accuracy may be relatively low. Alternatively, the number of times a storage system 32 with high control accuracy can participate in the service may be increased.

Note that even for storage systems 32 included in the same storage system group 50, the charge/discharge amount allocated for ancillary services may differ depending on, for example, the implementation status of the energy management service. As a result, for some storage systems 32 included in the storage system group 50, the charge/discharge amount allocated for ancillary services may be less than the charge/discharge amount desired by the upper control device 11. Even in this case, as long as the charge/discharge amount desired by the upper control device 11 can be secured for the storage system group 50 as a whole, operation as described above is possible.

Furthermore, by allowing only some of the storage systems 32 included in the storage system group 50 to perform charging and discharging, the amount of charging and discharging per storage system 32 can be increased, and the proportion of error in the amount of charging and discharging can be reduced.
For example, if the charge/discharge request amount in the service execution request is 80 kilowatts, 100 B type power storage systems 32B can each charge/discharge 800 watts, thereby achieving 80 kilowatts of charge/discharge. In this case, the error rate for the charge/discharge amount is 25/80≈31 percent.

Here, even if only 10 of the 100 B-type power storage systems 32B are configured to charge and discharge at 8,000 watts each, it is possible to charge and discharge 80 kilowatts. In this case, the error due to the 10 B-type power storage systems 32B is 250 x 10 = 2,500 watts = 2.5 kilowatts. The ratio of the error to the charge and discharge amount is 2.5/80 ≒ 3 percent.

In this way, when charging/discharging is performed on only some of the power storage systems 32 included in the power storage system group 50, the upper control device 11 may notify the middle-level control device 21 of the number of power storage systems 32 to be charged/discharged, in addition to the charge/discharge command value for the power storage system group 50. Then, the middle-level control device 21 may select the notified number of power storage systems 32 from among the power storage systems 32 included in the power storage system group 50, and cause them to charge/discharge.
At this time, the intermediate control device 21 may switch the selected power storage system 32 in a time-division manner to equalize the opportunity to participate in the service.

FIG. 10 is a flowchart showing an example of a procedure of processing performed by the upper level control device 11.
10, the request amount information acquisition unit 191 acquires information indicating the charge/discharge request amount in the ancillary service and information indicating the allowable error (step S111). The information indicating the charge/discharge request amount and the information indicating the allowable error are also referred to as request amount information.
When a target minimum percentage of error is set, the request amount information acquisition unit 191 further acquires information indicating the target minimum percentage of error.

Next, the group command value calculation unit 192 calculates, for each power storage system group 50, a charge/discharge power lower limit value for achieving the allowable error (step S112).
When a target minimum error rate is set, the group command value calculation unit 192 further calculates the charge/discharge amount required to achieve the target minimum error rate for each power storage system group 50. The charge/discharge amount for the ancillary service and the charge/discharge amount for the energy management service are allocated so as to ensure this charge/discharge amount. The upper control device 11 may allocate the charge/discharge amount for the ancillary service and the charge/discharge amount for the energy management service, and notify the lower control device 31 of the allocated charge/discharge amount.

Then, the group command value calculation unit 192 determines the power storage system groups 50 to be charged or discharged, and the charge/discharge amounts of the power storage system groups 50 (step S113).
Specifically, the group command value calculation unit 192 assigns a charge/discharge command value to the power storage system group 50 so that the charge/discharge amount of each of the power storage system group 50 is within a range of not less than the charge/discharge power lower limit value and not more than the charge/discharge amount assigned to the ancillary service, or is 0. Assigning a charge/discharge command value 0 to the power storage system group 50 means that the power storage system group is not allowed to perform charging/discharging for the ancillary service.

Next, the first communication unit 110 transmits a charge/discharge command indicating a charge/discharge command value for each power storage system group 50 to the intermediate control device 21 in accordance with the control of the group command value transmission processing unit 193 (step S114).
After step S114, the host controller 11 ends the process of FIG.

FIG. 11 is a flowchart showing an example of a procedure of processing performed by the intermediate control device 21.
In the process of FIG. 11, the group command value acquisition unit 291 acquires information on a charge/discharge command value for the power storage system group 50, which is indicated in a charge/discharge command from the upper level control device 11 (step S121).

Next, the individual command value calculation unit 292 determines a charge/discharge command value for each charge/discharge system 30 (step S122). When the charge/discharge command value for the energy storage system group 50 is expressed as a percentage of the charge/discharge amount allocated to the ancillary service, the individual command value calculation unit 292 may use the percentage as it is as information indicating the charge/discharge command value for each charge/discharge system 30.

Next, the second communication unit 210 transmits a charge/discharge command indicating a charge/discharge command value for each charge/discharge system 30 to the charge/discharge system 30 in accordance with the control of the individual command value transmission processing unit 293 (step S123).
After step S123, the intermediate control device 21 ends the process in FIG.

As described above, the group command value calculation unit 192 calculates a charge/discharge command value for the power storage system group 50 or at least one of the power storage systems 32 included in the power storage system group 50, based on the accuracy of charge/discharge control of the power storage system group 50 including a plurality of power storage systems 32. The first communication unit 110 transmits the charge/discharge command value calculated by the group command value calculation unit 192.
This allows the group command value calculation unit 192 to determine the charge/discharge command value taking into account the accuracy of the charge/discharge control of the power storage system 32, and in this respect, it is possible to meet the requirement for accuracy of the charge/discharge control.

In addition, by taking into consideration the charging and discharging accuracy for each group of energy storage systems, the upper control device 11 makes it possible to keep the total error of the entire power system 1 within a certain range (within the desired error) even when multiple energy storage systems with different rated outputs of power conditioning systems and different charging and discharging control accuracy are combined and integrated for control for various purposes (services) with different required errors.

The higher-level control device 11 can avoid the requirement for excessively small error in the low output range as a specification requirement for a storage system 32 with a large rated charge/discharge amount, and the requirement for the storage system 32 with a small rated charge/discharge amount of the same accuracy as a storage system 32 with a large rated value, and in this respect, the unit price of the storage system 32 can be kept low. By avoiding the bottleneck of the cost of the storage system 32, the power system 1 can be used for various purposes, which can contribute to the widespread use of the storage system 32.

According to the upper control device 11, multiple storage systems 32 can be controlled in an integrated manner, and even when used for frequency adjustment services, a wide range of storage systems 32 can be used, from those with large rated charge/discharge amounts to those with small rated charge/discharge amounts. In this respect, it becomes easier to secure storage systems 32 that can be used for frequency control.

In addition, by grouping the energy storage systems 32 into energy storage system groups 50, the group command value calculation unit 192 only needs to determine the charge/discharge amount for each energy storage system group 50, making the processing simpler than when the charge/discharge amount for each energy storage system 32 is determined directly.

Furthermore, the group command value calculation unit 192 calculates a charge/discharge amount lower limit value for the proportion of the error expected value, which is indicated by the proportion of the maximum value of the allowable error for the charge/discharge amount of the power storage system group 50, to the allowable error proportion upper limit value based on the error expected value in the charge/discharge of the power storage system group 50 and the required accuracy for the charge/discharge control as the upper limit value of the allowable error proportion for the charge/discharge request amount in the service execution request. Then, the group command value calculation unit 192 calculates a charge/discharge command value that is equal to or greater than the charge/discharge amount lower limit value.
The group command value calculation unit 192 only needs to determine the charge/discharge command value for each power storage system group 50 so as to satisfy the upper limit of the allowable error ratio for each power storage system group 50, and does not need to determine whether the upper limit of the allowable error ratio is satisfied in relation to the charge/discharge command values of the other power storage system groups 50. In this respect, the processing performed by the group command value calculation unit 192 can be simplified.

Furthermore, the group command value calculation unit 192 calculates the minimum charge/discharge amount upper limit value for which the ratio of the error expected value to the charge/discharge amount of the energy storage system group 50 becomes the error rate lower limit value based on the error expected value and the error rate lower limit value set for the charge/discharge request amount in the service implementation request. Then, the group command value calculation unit 192 sets the upper limit value of the charge/discharge command value to a value equal to or greater than the charge/discharge amount upper limit value minimum value.

This enables the group command value calculation unit 192 to determine the charge/discharge command value for the power storage system group 50 so as to achieve the error rate lower limit value.
In addition, the charge/discharge system 30 can use the remaining charge/discharge amount, which is equal to the upper limit of the charge/discharge power amount, for the energy management service, after reserving the charge/discharge amount for the ancillary service. This allows the charge/discharge system 30 to simultaneously perform charging/discharging for the ancillary service and charging/discharging for the energy management service.

Furthermore, the group command value calculation unit 192 calculates the charge/discharge amount lower limit by dividing the error expected value by the allowable error rate upper limit.
In this manner, the group command value calculator 192 can calculate the charge/discharge amount lower limit value through simple calculation.

In addition, the group command value calculation unit 192 determines which of the multiple storage system groups 50 should be caused to perform charging and discharging based on at least one of the history of charging and discharging time, the history of charging and discharging power amount, or the history of the number of times participation in the service through charging and discharging for each storage system group 50.
This enables the group command value calculation unit 192 to ensure equality of opportunities to participate in the service (ancillary service) of the charge/discharge system 30.

In addition, the group command value calculation unit 192 determines which of the multiple storage system groups is to perform charging and discharging based on an expected error value in charging and discharging the storage system group 50 and an upper limit value of the allowable error ratio for the charging and discharging request amount in the service implementation request.
The group command value calculation unit 192 can achieve the allowable error ratio upper limit by determining the power storage system group 50 to be caused to perform charging/discharging.

Furthermore, the group command value calculation unit 192 determines the number of power storage systems 32 to be charged or discharged among the multiple power storage systems 32 included in one power storage system group 50. The first communication unit 110 transmits information indicating the number of power storage systems 32 to be charged or discharged, in addition to the charge/discharge command value.
According to the higher-level control device 11, the amount of charge and discharge per unit of the power storage system 32 can be increased, and in this respect, the accuracy of the charge and discharge control can be improved.

Furthermore, the group command value calculation unit 192 calculates the amount of charging and discharging to be performed by the power storage system group 50 as a charge/discharge command value based on the amount of charging and discharging secured in the power storage system group.
Since the group command value calculation unit 192 calculates the charge/discharge command value based on the charge/discharge amount secured in the storage system group 50, it is expected that the intermediate control device 21 can easily calculate the charge/discharge amount for the storage system based on the charge/discharge amount secured in each storage system 32.

For example, the group command value calculation unit 192 calculates, as the charge/discharge command value, a ratio obtained by dividing the amount of charging/discharging to be performed by the power storage system group 50 by the amount of charging/discharging secured in the power storage system group.
When the intermediate-level control device 21 causes the storage systems 32 included in this storage system group 50 to charge and discharge evenly, the charge and discharge command value calculated by the group command value calculation unit 192 can be used as is as the charge and discharge command value for the storage systems 32.

As described above, the upper control device 11 and the middle-level control device 21 may be configured as a single device. For example, in the example of FIG. 1, the middle-level control device 21 may be configured as a control device that has both the functions of the upper control device 11 and the middle-level control device 21.

In this case, a service implementation request for the power system 1 may be transmitted from the upper control device 11 to the intermediate control device 21. In other words, a service implementation request for the entire group of storage systems 50 included in the power system 1 may be transmitted from the upper control device 11 to the intermediate control device 21.

In a service execution request from the upper level control device 11 to the middle level control device 21, in addition to the charge/discharge request amount, information on the required accuracy of charge/discharge, such as an upper limit value of an allowable error rate, may be notified, and further, information on the target accuracy of charge/discharge, such as a lower limit value of an error rate, may be notified. Alternatively, in a case where the upper limit value of an allowable error rate is set in advance, for example, the upper level control device 11 may notify only the charge/discharge request amount in a service execution request to the middle level control device 21.
The upper level control device 11 may notify the charge/discharge request amount in the form of a standardized value as described above.

In addition, in addition to or instead of requesting service to be performed by the mid-level control device 21, the upper control device 11 may directly indicate the charge/discharge request amount to a charging/discharging system 30 that is not subject to control by the mid-level control device 21, without going through the mid-level control device 21, to cause charging/discharging to be performed.

For example, a case will be considered in which there is a power storage system 32 included in the power storage system group 50 and another power storage system 32 not included in any of the power storage system groups 50 .
In this case, as described above, the group command value calculation unit 192 of the upper control device 11 calculates the charge/discharge amount lower limit value of each of the power storage system groups 50. Furthermore, the group command value calculation unit 192 calculates the charge/discharge amount lower limit value of the power storage system 32 that is not included in any of the power storage system groups 50.

As in the case of the energy storage system group 50, in the case of the energy storage system 32 alone, the group command value calculation unit 192 calculates the charge/discharge amount lower limit value by dividing the error expected value by the upper limit value of the allowable error ratio. In this case, the group command value calculation unit 192 uses the error expected value of the energy storage system 32 alone as it is as the error expected value.

Then, the group command value calculation unit 192 assigns charge/discharge command values to the storage system group 50 and the storage system 32 so that the charge/discharge amount of the storage system group 50 becomes equal to or greater than the lower limit of the charge/discharge amount of the storage system group 50 or becomes zero, and the charge/discharge amount of a storage system 32 that is not included in any of the storage system groups 50 becomes equal to or greater than the lower limit of the charge/discharge amount of the storage system 32 or becomes zero.
The group command value calculation unit 192 may treat a storage system 32 that is not included in any of the storage system groups 50 as a storage system group 50 having one storage system 32, and calculate the above-mentioned charge/discharge amount lower limit value and allocate the charge/discharge amount.

The group command value transmission processing unit 193 of the upper control device 11 controls the first communication unit 110 to transmit a charge/discharge command for the energy storage system group 50 to the intermediate control device 21. The group command value transmission processing unit 193 also controls the first communication unit 110 to transmit a charge/discharge command for a energy storage system 32 that is not included in any of the energy storage system groups 50 to the lower control device 31 that controls that energy storage system 32.

In this way, the group command value calculation unit 192 calculates a charge/discharge command for the storage system group 50, and for a storage system 32 that is not included in any of the storage system groups 50, calculates a charge/discharge command value for that storage system 32 based on the accuracy of the charge/discharge control of that storage system 32.
This allows the group command value calculation unit 192 to calculate the charge/discharge command value within the allowable error range in response to the case where there is a power storage system 32 that is not included in any of the power storage system groups 50.

When the middle-level control device 21 is configured as a control device having both the functions of the higher-level control device 11 and the functions of the middle-level control device 21, the middle-level control device 21 allocates the charge/discharge request amount to the power storage system group 50 so as to satisfy the condition of the allowable error rate upper limit value, and determines the charge/discharge request amount for the power storage system group 50. The middle-level control device 21 may calculate the charge/discharge request amount for the power storage system group using the standardized value as described above.
This process corresponds to the process described as the process of the upper level control device 11 in the above example.

Then, the intermediate control device 21 allocates the charge/discharge demand amount for the storage system group to the charge/discharge system 30 included in the storage system group, and determines the charge/discharge demand amount for the charge/discharge system 30. When the charge/discharge demand amount for the storage system group is indicated by a standardized value, and the rated charge/discharge amount values for all of the charge/discharge systems 30 can be used for ancillary services, as described above, the standardized value of the charge/discharge demand amount for the storage system group 50 can be used as the standardized value of the charge/discharge demand amount for the charge/discharge system 30 as it is.

This process corresponds to the process described as the process of the intermediate control device 21 in the above example.
In this way, the intermediate control device 21 may be configured to execute both the functions described above as the functions of the upper control device 11 and the functions described above as the functions of the intermediate control device 21.

12 is a diagram showing an example of the configuration of a control device according to the embodiment. In the configuration shown in FIG. 12, a control device 610 includes a command value calculation unit 611 and a command value transmission unit 612.
In this configuration, the command value calculation unit 611 calculates a charge/discharge command value based on the accuracy of charge/discharge control of the power storage system. The command value transmission unit 612 transmits the charge/discharge command value calculated by the command value calculation unit 611. The command value calculation unit 611 corresponds to an example of a command value calculation means. The command value transmission unit 612 corresponds to an example of a command value transmission means.
This allows the command value calculation unit 611 to determine the charge/discharge command value taking into consideration the accuracy of the charge/discharge control of the power storage system, and in this respect, it is possible to meet the requirement for accuracy of the charge/discharge control.

FIG. 13 is a diagram illustrating an example of a processing procedure in the control method according to the embodiment.
The control method shown in FIG. 13 includes a step of calculating a charge/discharge command value (step S611) and a step of transmitting the charge/discharge command value (step S612).
In the step of calculating a charge/discharge command value (step S611), the charge/discharge command value is calculated based on the accuracy of charge/discharge control of the power storage system. In the step of transmitting the charge/discharge command value (step S612), the charge/discharge command value calculated in step S611 is transmitted.
According to the control method shown in FIG. 13, the charge/discharge command value can be determined taking into consideration the accuracy of charge/discharge control of the power storage system, and in this respect, the requirement for accuracy of charge/discharge control can be met.

Figure 14 is a schematic block diagram showing the configuration of a computer according to at least one embodiment. In the configuration shown in Figure 14, the computer 700 includes a CPU 710, a main memory device 720, an auxiliary memory device 730, and an interface 740.

Any one or more of the above-mentioned upper control device 11, middle control device 21 and control device 610 may be implemented in the computer 700. In this case, the operation of each of the above-mentioned processing units is stored in the auxiliary storage device 730 in the form of a program. The CPU 710 reads the program from the auxiliary storage device 730, expands it in the main storage device 720, and executes the above-mentioned processing according to the program. The CPU 710 also secures a memory area in the main storage device 720 corresponding to each of the above-mentioned memory units according to the program. Communication between each device and other devices is executed by the interface 740 having a communication function and communicating according to the control of the CPU 710.

When the upper level control device 11 is implemented in the computer 700, the operations of the first control unit 190 and each of its units are stored in the form of a program in the auxiliary storage device 730. The CPU 710 reads the program from the auxiliary storage device 730, loads it into the main storage device 720, and executes the above-mentioned processing in accordance with the program.
Furthermore, the CPU 710 reserves a memory area corresponding to the first memory unit 180 in the main memory device 720 in accordance with the program.
The communication by the first communication unit 110 is executed by the interface 740 having a communication function and performing communication under the control of the CPU 710 .

When the intermediate control device 21 is implemented in the computer 700, the operations of the second control unit 290 and each of its units are stored in the form of a program in the auxiliary storage device 730. The CPU 710 reads the program from the auxiliary storage device 730, loads it into the main storage device 720, and executes the above-mentioned processing in accordance with the program.
Furthermore, the CPU 710 reserves a memory area corresponding to the second memory unit 280 in the main memory device 720 in accordance with the program.
The communication by the second communication unit 210 is executed by the interface 740 having a communication function and performing communication under the control of the CPU 710 .

When the control device 610 is implemented in the computer 700, the operation of the command value calculation unit 611 is stored in the form of a program in the auxiliary storage device 730. The CPU 710 reads the program from the auxiliary storage device 730, loads it into the main storage device 720, and executes the above-mentioned processing in accordance with the program.
The charge/discharge command value is transmitted by the command value transmitting unit 612 through communication performed by the interface 740 having a communication function and under the control of the CPU 710 .

Note that the programs for executing all or part of the processes performed by the upper control device 11, the middle control device 21, and the control device 610 may be recorded on a computer-readable recording medium, and the programs recorded on the recording medium may be read into a computer system and executed to perform the processes of each part. Note that the term "computer system" here includes hardware such as the OS and peripheral devices.
Furthermore, the term "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs (Read Only Memory), and CD-ROMs (Compact Disc Read Only Memory), as well as storage devices such as hard disks built into computer systems. The above-mentioned program may be for realizing part of the above-mentioned functions, or may be capable of realizing the above-mentioned functions in combination with a program already recorded in the computer system.

Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment and also includes designs that do not deviate from the gist of the present invention.

Embodiments of the present invention may be applied to control devices.

REFERENCE SIGNS LIST 1 Power system 10 Upper control system 11 Upper control device 110 First communication unit 180 First memory unit 190 First control unit 191 Request amount information acquisition unit 192 Group command value calculation unit 193 Group command value transmission processing unit 91 Gateway device 20 Middle-level control system 21 Middle-level control device 210 Second communication unit 280 Second memory unit 290 Second control unit 291 Group command value acquisition unit 292 Individual command value calculation unit 293 Individual command value transmission processing unit 30 Charging/discharging system 31 Lower-level control device 32 Power storage system 610 Control device 611 Command value calculation unit 612 Command value transmission unit

Claims (8)

a command value calculation means for determining a storage system group to be charged/discharged from among the plurality of storage system groups based on an estimated error value in charging/discharging of the storage system group including the plurality of storage systems and an upper limit value of an allowable error rate for a charge/discharge request amount in the service execution request, and for calculating a charge/discharge command value for the storage system group based on an accuracy of charge/discharge control of the determined storage system group ;
A command value transmitting means for transmitting the charge/discharge command value;
A control device comprising: the command value calculation means calculates a charge/discharge command for the power storage system group, and for a power storage system not included in any of the power storage system groups, calculates a charge/discharge command value for the power storage system based on accuracy of charge/discharge control of the power storage system;
The control device according to claim 1 . the command value calculation means calculates a charge/discharge amount lower limit value for a ratio of the error estimated value to the charge/discharge amount of the power storage system group to the allowable error ratio upper limit value based on an error estimated value in the charge/discharge of the power storage system group and an allowable error ratio upper limit value indicating a required accuracy for the charge/discharge control as a ratio of a maximum allowable error to a charge/discharge request amount in a service execution request, and calculates the charge/discharge command value that is equal to or greater than the charge/discharge amount lower limit value.
The control device according to claim 1 or 2. The command value calculation means calculates a minimum charge/discharge amount upper limit value for which the ratio of the error expected value to the charge/discharge amount of the group of energy storage systems becomes the lower limit error proportion value based on the expected error value and a lower limit error proportion value set for the charge/discharge required amount, and sets an upper limit value of the charge/discharge command value to a value equal to or greater than the minimum upper limit charge/discharge amount value.
The control device according to claim 3. The command value calculation means calculates the charge/discharge amount lower limit value by dividing the error expected value by the allowable error rate upper limit value.
The control device according to claim 3 or 4. the command value calculation means determines, for each of the plurality of power storage system groups, a power storage system group to be charged or discharged, based on at least one of a history of a charging/discharging implementation time, a history of a charging/discharging power amount, and a history of a number of times of participation in a service through the implementation of charging/discharging, for each of the power storage system groups;
A control device according to any one of claims 1 to 5. the command value calculation means determines the number of power storage systems to be charged or discharged from among the plurality of power storage systems included in one of the power storage system groups;
The command value transmitting means transmits information indicating the number in addition to the charge/discharge command value.
A control device according to any one of claims 1 to 6 . the command value calculation means calculates an amount of charging/discharging to be performed by the power storage system group, as the charge/discharge command value, based on an amount of charging/discharging secured in the power storage system group;
A control device according to any one of claims 1 to 7 .

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