JP7673702B2 - Power transfer system - Google Patents

Description

This disclosure relates to a power transfer system that transfers power.

Conventional power supply systems that rely on power generation by electric power companies and other electric power suppliers are being reconsidered, and a system known as a Virtual Power Plant (VPP) is being considered that uses advanced energy management technology that utilizes the Internet of Things (IoT) to bundle multiple distributed energy resources (hereinafter also referred to as "Distributed Energy Resources (DERs)") and remotely and centrally control these DERs to function as if they were a single power plant. JP 2020-156149 A (Patent Document 1) discloses a VPP system that can transfer power between the power grid of an electric power supplier and the battery of a vehicle used as a DER.

JP 2020-156149 A

According to the VPP system disclosed in Patent Document 1, power transactions are performed in advance between an aggregator that receives a request for power transfer from an electric utility and each user of a plurality of vehicles, and then power can be transferred between the power grid and the plurality of vehicles during the scheduled execution period. However, in the VPP system, transactions are performed in advance between the plurality of vehicles to keep the actual value within the allowable range of the target power for power transfer. For this reason, there is a risk that the target power for power transfer cannot be met during the subsequent execution period due to various factors.

This disclosure has been made to solve the above problems, and the purpose of this disclosure is to provide technology that can satisfy the target power for power transfer.

The power transfer system according to an aspect of the present disclosure includes a power grid of an electric utility company, a plurality of vehicles, and a server device that transfers power between the power grid and each of the plurality of vehicles. The server device plans power transfer with at least one vehicle among the plurality of vehicles to satisfy a target power for power transfer, and further plans power transfer with at least one spare vehicle. If the server device determines that the target power for the execution period can be satisfied by power transfer using at least one vehicle in a preliminary period prior to the execution period in which power transfer is performed, the server device transfers power using at least one spare vehicle in the preliminary period.

According to the present disclosure, since power transfer is scheduled with at least one spare vehicle in addition to at least one vehicle for satisfying the target power of power transfer, even if the target power of power transfer during the execution period cannot be satisfied by at least one vehicle with which a transaction has been made in advance, the target power of power transfer during the execution period can be satisfied using at least one spare vehicle. On the other hand, even if the target power during the execution period can be satisfied by power transfer using at least one vehicle with which a transaction has been made in advance, power transfer is performed using at least one spare vehicle in the advance period, so that power transfer can be performed as planned with at least one spare vehicle.

1 is a diagram for explaining an example of a configuration of an electric power transfer system according to an embodiment. 1 is a diagram for explaining an overview of a VPP system to which an electric power transfer system according to an embodiment is applied; FIG. 11 is a diagram showing an example of a transition of a target power with respect to the passage of time in power transfer. 4 is a flowchart showing a procedure of a process executed in the power transfer system according to the embodiment.

The following describes in detail the embodiments of the present disclosure with reference to the drawings. Note that in the drawings, the same or corresponding parts are given the same reference numerals and their description will not be repeated.

[Configuration of power transfer system]
Fig. 1 is a diagram for explaining an example of a configuration of an electric power transfer system 1 according to an embodiment. As shown in Fig. 1, the electric power transfer system 1 includes an electric power system PG, a vehicle 50, a server device 30, an EMS (Energy Management System) 60, an EVSE (Electric Vehicle Supply Equipment) 40, a smart meter 13, and a user terminal 80, and realizes a VPP by energy management using the vehicle 50.

The power grid PG is a power network provided by an electric power supplier such as a power company. The power grid PG is electrically connected to multiple EVSEs 40, and supplies power to each EVSE 40 and receives power from each EVSE 40.

The vehicle 50 is, for example, a battery electric vehicle (BEV) or a plug-in hybrid electric vehicle (PHEV). The vehicle 50 may be a personally owned POV (Personally Owned Vehicle) or a vehicle managed by a Mobility as a Service (MaaS) operator. The vehicle 50 includes a battery 130, an electronic control unit (ECU) 150, a communication device 180, an inlet 110, and a charger/discharger 120.

The battery 130 includes a secondary battery such as a lithium ion battery or a nickel metal hydride battery. The secondary battery may be, for example, a battery pack in which multiple lithium ion batteries are electrically connected to each other. The vehicle 50 can run using the power stored in the battery 130.

The ECU 150 is a computer including a processor, a RAM (Random Access Memory), and a storage device. The processor is, for example, a microcontroller, a CPU (central processing unit), or an MPU (Micro-processing unit). The processor has a function of executing various processes by executing a program, but some or all of these functions may be implemented using a dedicated hardware circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). The term "processor" is not limited to a processor in the narrow sense that executes processes using a stored program method such as a CPU or an MPU, but may also include hardwired circuits such as an ASIC or an FPGA. For this reason, the processor can also be interpreted as a processing circuitry in which processing is defined in advance by computer-readable code and/or hardwired circuits. The RAM is a volatile memory such as a DRAM (Dynamic Random Access Memory) or an SRAM (Static Random Access Memory), and functions as a working memory that temporarily stores data to be processed by the processor. The storage device is a non-volatile memory such as a ROM (Read Only Memory) or a flash memory, and stores programs as well as various data used by the programs (for example, maps, formulas, and various parameters). Note that the ECU 150 may be configured as a single chip or multiple chips.

The communication device 180 includes various communication I/Fs (interfaces). The ECU 150 is configured to be able to communicate with the user terminal 80 via the communication device 180.

The inlet 110 is configured to be connectable to the connector 43 of the charging cable 42, and receives power supplied from outside the vehicle 50 and supplies power to the outside of the vehicle 50 via the charging cable 42. For example, the vehicle 50 becomes capable of charging and discharging when the connector 43 of the charging cable 42 connected to the EVSE 40 is connected (plugged in) to the inlet 110 of the vehicle 50.

The charger/discharger 120 is disposed between the inlet 110 and the battery 130. The charger/discharger 120 includes a relay that switches between connecting and disconnecting the power path from the inlet 110 to the battery 130, and a power conversion circuit (e.g., a bidirectional converter). Each of the relays and power conversion circuits included in the charger/discharger 120 is controlled by the ECU 150.

When the vehicle 50 is in a chargeable/dischargeable state, it is possible to perform external charging (i.e., charging the battery 130 with power supplied from the EVSE 40) and external discharging (i.e., discharging from the vehicle 50 to the EVSE 40). Power for external charging is supplied from the EVSE 40 to the inlet 110 via the charging cable 42. The charger/discharger 120 converts the power received by the inlet 110 into power suitable for charging the battery 130 and outputs the converted power to the battery 130. Power for external discharging is supplied from the battery 130 to the charger/discharger 120. The charger/discharger 120 converts the power supplied from the battery 130 into power suitable for external discharging and outputs the converted power to the inlet 110. When performing either external charging or external discharging, the ECU 150 controls the relay of the charger/discharger 120 to a closed state (connected state), and when neither external charging nor external discharging is performed, the ECU 150 controls the relay of the charger/discharger 120 to an open state (disconnected state).

The server device 30 includes a control device 31, a storage device 32, and a communication device 33, and realizes, for example, some or all of the functions as a cloud-type server device.

The control device 31 is a computer including a processor and RAM. The processor is, for example, a microcontroller, a CPU, or an MPU. The processor has the function of executing various processes by executing a program, but some or all of these functions may be implemented using a dedicated hardware circuit such as an ASIC or an FPGA. The term "processor" is not limited to a processor in the narrow sense that executes processes using a stored program method such as a CPU or an MPU, but may also include a hardwired circuit such as an ASIC or an FPGA. For this reason, the processor can also be interpreted as a processing circuitry in which processing is defined in advance by computer-readable code and/or a hardwired circuit. The RAM is a volatile memory such as a DRAM or an SRAM, and functions as a working memory that temporarily stores data to be processed by the processor.

The storage device 32 is a storage device such as a non-volatile memory, such as a ROM or flash memory, a solid state drive (SSD) or a hard disk drive (HDD), and stores not only the program but also various data used by the program (for example, maps, formulas, and various parameters).

The communication device 33 includes various communication I/Fs (interfaces). The control device 31 is configured to be able to communicate with the user terminal 80 via the communication device 33. For communication between the communication device 33 and the user terminal 80, wireless communication such as Wi-Fi or Bluetooth (registered trademark) may be used.

The EMS 60 communicates with the EVSE 40 according to instructions from the server device 30. The EMS 60 is, for example, a Home Energy Management System (HEMS), a Factory Energy Management System (FEMS), or a Building Energy Management System (BEMS). The server device 30 communicates with the EVSE 40 via the EMS 60, without communicating directly with the EVSE 40.

The EVSE 40 is, for example, an AC power supply facility capable of supplying AC power, in which case the charger/discharger 120 of the vehicle 50 has a circuit corresponding to the AC power supply facility. The EVSE 40 may also be a DC power supply facility capable of supplying DC power, in which case the charger/discharger 120 of the vehicle 50 may have a circuit corresponding to the DC power supply facility. EVSE 40 includes non-public EVSEs (for example, home EVSEs) that are available only to specific users, and public EVSEs that are available to an unspecified number of users. The EVSE 40 includes a control unit 41, a power supply circuit 44, and a charging cable 42.

The control unit 41 controls the power supply circuit 44 to supply power to the battery 130 of the vehicle 50 via the charging cable 42 and to receive power from the battery 130 of the vehicle 50.

The power supply circuit 44 is connected to the charging cable 42. The power supply circuit 44 supplies power to the battery 130 of the vehicle 50 via the charging cable 42 and receives power from the battery 130 of the vehicle 50 according to the control of the control unit 41.

The charging cable 42 may be always connected to the main body of the EVSE 40, or may be detachable from the main body of the EVSE 40. The charging cable 42 has a connector 43 at its tip and includes a power line inside.

The smart meter 13 is assigned to each consumer (e.g., an individual or a business) that uses electricity, and measures the amount of power adjustment at the consumer every time a predetermined time (e.g., 30 minutes) has elapsed. For example, the smart meter 13 measures the amount of power supplied from the power grid PG to the EVSE 40, or the amount of power supplied from the EVSE 40 to the power grid PG. The smart meter 13 transmits a signal including information indicating the measured amount of power adjustment to the server device 30. Note that instead of the smart meter 13, a power meter mounted on the vehicle 50 or a power meter built into the EVSE 40 may be used.

The EVSE 40 and EMS 60 described above are installed in one home or business (e.g., a factory or commercial facility). The smart meter 13 measures the amount of power adjustment that is adjusted between the power grid PG and the home or business.

The user terminal 80 is an information terminal capable of communicating with each of the server device 30 and the vehicle 50 via a network, such as a desktop personal computer (PC), a laptop PC, a smartphone, a smart watch, a wearable device, or a tablet PC. The user terminal 80 may be a mobile terminal that the user can carry with them, or an information terminal installed in the vehicle 50, such as a navigation system.

Although not shown, the navigation system includes a processor, a storage device, a touch panel display, and a GPS (Global Positioning System) module. The storage device stores map information. The touch panel display accepts input from the user and displays maps and other information. The GPS module receives GPS signals from GPS satellites. The navigation system can identify the position of the vehicle 50 using the GPS signals. Based on the input from the user, the navigation system performs a route search to find a driving route (e.g., the shortest route) from the current position of the vehicle 50 to the destination, and can display the driving route found by the route search on the map on the touch panel display.

A specific application software (hereinafter, simply referred to as an "app") is installed on the user terminal 80. The user terminal 80 is used by the user of the vehicle 50, and exchanges information with the server device 30 through the app. For example, the user can participate in the VPP by exchanging information with the server device 30 using the VPP app installed on the user terminal 80.

[Outline of the VPP System]
Fig. 2 is a diagram for explaining an outline of a VPP system to which the power transfer system 1 according to the embodiment is applied. As shown in Fig. 2, the power transfer system 1 includes a power company E1, a higher-level aggregator E2, a lower-level aggregator E3, and a plurality of vehicles 50A, 50B, and 50C. Each of the plurality of vehicles 50A, 50B, and 50C corresponds to the vehicle 50 shown in Fig. 1. In the example of Fig. 2, the power transfer system 1 includes an EVSE 40, an EMS 60, and a smart meter 13 corresponding to the plurality of vehicles 50A, and also includes an EVSE 40, an EMS 60, and a smart meter 13 (not shown) for each of the other vehicles 50B and 50C.

The power company E1 is an electric power company such as a power generation company or a power transmission and distribution company. In the example of FIG. 2, the power company E1 serves as both a power generation company and a power transmission and distribution company. The power company E1 includes a power plant 11, a power transmission and distribution facility 12, and a server device 10. The power company E1 constructs a power system PG using the power plant 11 and the power transmission and distribution facility 12, and maintains and manages the power system PG using the server device 10. The power plant 11 includes a power generation device for generating electricity, and supplies the power generated by the power generation device to the power transmission and distribution facility 12. The power plant 11 may use any known power generation method, such as thermal power generation, hydroelectric power generation, wind power generation, nuclear power generation, and solar power generation, as a power generation method. The power transmission and distribution facility 12 includes a transmission line, a substation, and a power distribution line, and transmits and distributes the power supplied from the power plant 11.

A business that aggregates DERs and performs energy management is also called an "aggregator." For example, the power company E1 can adjust the power in the power system PG by cooperating with an aggregator. The upper aggregator E2 includes multiple server devices (e.g., server devices 20A and 20B). The multiple server devices included in the upper aggregator E2 belong to different businesses. The lower aggregator E3 includes multiple server devices (e.g., server devices 30A and 30B). The multiple server devices included in the lower aggregator E3 belong to different businesses. Each server device included in the lower aggregator E3 shown in FIG. 2 corresponds to the server device 30 shown in FIG. 1. Hereinafter, except when a distinction is made, each server device included in the upper aggregator E2 will also be referred to as a "server device 20," and each server device included in the lower aggregator E3 will also be referred to as a "server device 30." The number of server devices 20 and the number of server devices 30 are independent of each other and can be set arbitrarily.

In the example of FIG. 2, one server device 10 requests energy management from multiple server devices 20 that are upper aggregators E2, and each server device 20 that receives a request from the server device 10 requests energy management from multiple server devices 30 that are lower aggregators E3. Furthermore, each server device 30 that receives a request from the server device 20 requests energy management from multiple DER users (e.g., users of vehicles 50). The power company E1 can use such a hierarchical structure (tree structure) to request energy management from many users. Note that the upper aggregator E2 and the lower aggregator E3 may be configured to function using the same server device.

A request from the power company E1 (server device 10) to the upper aggregator E2 (server device 20), a request from the upper aggregator E2 (server device 20) to the lower aggregator E3 (server device 30), and a request from the lower aggregator E3 (server device 30) to each user are also called DR (demand response) requests. DR refers to changing the power demand pattern by controlling the DER. A DR that uses DER to actively use power to increase power demand for each user is also called "increasing DR." On the other hand, a DR that reduces power demand for each user by saving or discharging power is also called "reducing DR."

The server device 30 performs energy management for the area under its jurisdiction. The area under the jurisdiction of the server device 30 may be a town (for example, a smart city), a factory, or a university campus. The lower aggregator E3 concludes an energy management contract with DER users in the area under the jurisdiction of the server device 30. Users who have concluded such a contract can receive a predetermined incentive from the lower aggregator E3 by performing energy management using DER in accordance with a DR request from the lower aggregator E3. On the other hand, a user who does not comply with a DR request from the lower aggregator E3 despite agreeing to comply with the DR request is subject to a predetermined penalty according to the above-mentioned contract. DERs and DER users who are obligated to perform energy management under the contract are registered in the server device 30.

When the server device 30 receives a DR request from the server device 20, it selects a DER to respond to the DR request from among the DERs registered in the server device 30. The DER selected in this manner is also referred to as an "EMDER." After selecting an EMDER, the server device 30 transmits instructions to the user of each EMDER. Based on the instructions received from the server device 30, the user of each EMDER performs energy management (for example, adjusting supply and demand in the power system PG) in accordance with the DR request from the server device 30.

The amount of power adjustment for each EMDER (e.g., charging power and/or discharging power in a specified period) is measured by the smart meter 13. The amount of power adjustment measured by the smart meter 13 is transmitted to the server device 10. In the example of FIG. 2, the server device 30 acquires the amount of power adjustment measured by the smart meter 13 via the server device 10, but the server device 30 may acquire the amount of power adjustment directly from the smart meter 13. The amount of power adjustment measured by the smart meter 13 may be used to calculate the incentive.

In the power transfer system 1 configured as described above, the server device 20 selects at least one vehicle that makes a DR request from among the registered vehicles 50 in order to satisfy the target power of the power transfer in accordance with a request from the power company E1 (server device 10) or the upper aggregator E2 (server device 20), and transmits the DR request to the user terminal 80 of the user of the selected at least one vehicle 50. When the user who received the DR request accepts the DR request using the user terminal 80, the server device 30 schedules power transfer using the selected at least one vehicle 50 during the execution period for executing the power transfer (DR request). When the execution period arrives, the server device 30 can transmit a DR signal to the EMS 60 to cause the vehicle 50 of the user who accepted the DR request to transfer power so as to satisfy the target power of the DR request.

Note that "electric power transfer" is a concept that includes at least one of the following: electric power is supplied from the electric power system PG to the vehicle 50 by charging the battery 130 of the vehicle 50 using the EVSE 40; and electric power is supplied from the vehicle 50 to the electric power system PG by discharging the battery 130 of the vehicle 50 using the EVSE 40. For example, when the server device 30 requests an increase DR from the user of the vehicle 50, electric power is supplied from the electric power system PG to the vehicle 50, or the supplied electric power is increased, as electric power transfer. On the other hand, when the server device 30 requests a decrease DR from the user of the vehicle 50, electric power is supplied from the electric power system PG to the vehicle 50, or conversely, electric power is supplied from the vehicle 50 to the electric power system PG, as electric power transfer.

Furthermore, satisfying the target power means that the actual value of the charging power or discharging power in the vehicle 50 obtained by the power transfer actually performed during the execution period falls within the allowable range of the target power (target value of charging power, target value of discharging power) during the execution period specified by the DR request.

The acceptable range is set, for example, to a range of ±10% of the target value of power transfer (total target value of charging power for all vehicles 50, total target value of discharging power for all vehicles 50) specified by the server device 30 for all vehicles 50 for which the DR request has been approved. Note that the target power (target value of charging power, target value of discharging power) during the execution period may be changeable. For example, the server device 30 may change the target power for the execution period once set, in accordance with a request from the power company E1 (server device 10) or the upper aggregator E2 (server device 20) before the execution period arrives. In this case, the server device 30 may make a DR request again to the vehicles 50 so as to satisfy the re-set changed target power.

[An example of the transition of power transfer over time]
Fig. 3 is a diagram showing an example of the transition of the target power over time in the power transfer. In Fig. 3, the transition of the target power over time in the power transfer is shown in a graph with time on the horizontal axis and charging power on the vertical axis. Note that Fig. 3 shows an example in which an up-DR is requested from the server device 30 to the users of each vehicle 50, and the vertical axis shows the total value of charging power supplied to each consumer from the power system PG.

The server device 30 adjusts the power supplied to each consumer from the power system PG so as to satisfy the target power specified by the DR request by transferring power using at least one selected vehicle 50. For example, as shown in FIG. 3, the server device 30 selects at least one vehicle 50 that makes a DR request from among the registered vehicles 50 in order to satisfy the target power that is increased from power P1 to power P2 in accordance with a request from the power company E1 or the upper aggregator E2, and plans to transfer power between the server device 30 and the at least one selected vehicle 50 during the execution period. For example, in the example shown in FIG. 2, the server device 30 selects vehicles 50A and 50B that make a DR request from vehicles 50A, 50B, and 50C, and plans to charge the vehicles 50A and 50B during the execution period.

At the DR update timing t1 before the execution period (for example, 45 minutes before the execution period), the server device 30 checks whether the target power P2 for the execution period specified by a request from the power company E1 or the upper aggregator E2 has been updated, and if the target power P2 has been updated, updates the target power P2 specified for at least one vehicle 50 that is scheduled to receive and transmit power during the execution period.

The server device 30 then gradually increases the target power from power P1 to power P2 during the advance period from timing t2 before the execution period (e.g., 30 minutes before the execution period) to timing t3 at which the execution period begins and at which the DR request is executed.

At the DR request execution timing t3, the server device 30 executes a DR request for at least one vehicle 50 that has accepted the DR request, and adjusts the charging power supplied from the power system PG to at least one vehicle 50 within an allowable range so as to satisfy the target power P2.

In this way, according to the power transfer system 1, a power transfer transaction is carried out in advance between the server device 30, which has received a request for power transfer from the power company E1 or the upper aggregator E2, and each user of the multiple vehicles 50, and then power can be transferred between the power system PG and at least one vehicle 50 during the scheduled execution period.

Here, the user of the vehicle 50 who has accepted the DR request is obligated to connect the connector 43 of the charging cable 42 of the EVSE 40 to the inlet 110 of the vehicle 50 before the advance period arrives. In this way, all the vehicles 50 who have accepted the DR request can complete preparations to execute power transfer before the execution period begins. However, due to various factors such as a sudden change in the user's schedule, road conditions such as traffic jams, or malfunctions of the vehicles 50, in reality, all the vehicles 50 who have accepted the DR request may not be able to execute power transfer during the execution period. In such a case, the server device 30 may not be able to secure the number of vehicles 50 to satisfy the target power P2 for power transfer, and may not be able to keep the actual value of power transfer within the allowable range of the target power P2.

In addition, at the DR update timing t1, the target power P2 for the execution period may be updated. For example, if the target power P2 is raised, the server device 30 may not be able to secure the charging power requested by the power company E1 or the upper aggregator E2 even if all vehicles 50 that have approved the DR request are used, and may not be able to satisfy the target power P2 for power exchange within the allowable range.

Note that FIG. 2 shows an example of power transfer in which the vehicle 50 is charged using power supplied from the power grid GP, but the same issues as in the example shown in FIG. 2 also arise when the vehicle 50 supplies power to the power grid GP by discharging the power.

Therefore, in the power transfer system 1 according to the embodiment, the server device 30 is configured to schedule power transfer with at least one vehicle 50 to meet the target power for power transfer, and also to make a DR request in advance to at least one spare vehicle 50 (hereinafter also referred to as a "spare vehicle 50") and obtain approval for the DR request from the at least one spare vehicle 50.

For example, in the example shown in FIG. 2, the server device 30 schedules the exchange of power with the vehicle 50A, 50B that is making the DR request from among the vehicles 50A, 50B, and 50C, and also makes a DR request in advance to the spare vehicle 50C, and obtains approval for the DR request from the spare vehicle 50C as well.

As a result, even if all of the vehicles 50 (e.g., vehicles 50A and 50B) that have accepted the DR request are unable to exchange power during the execution period, the server device 30 can fulfill the target power for power exchange by executing power exchange during the execution period using a spare vehicle 50 (e.g., vehicle 50C) instead of the vehicle 50 (e.g., vehicle 50B) that is unable to exchange power. Also, even if the target power is updated at the DR update timing t1, the server device 30 can fulfill the target power for power exchange by executing power exchange during the execution period using a spare vehicle 50 (e.g., vehicle 50C) in addition to the vehicles 50 (e.g., vehicles 50A and 50B) that have accepted the DR request.

Here, as a result, all the vehicles 50 that have accepted the DR request may complete preparations for executing power transfer before the start of the execution period, and the target power may be met by power transfer using the vehicles 50 that have completed preparations without using the reserve vehicle 50. In such a case, it is assumed that the reserve vehicle 50 that has accepted the DR request cannot receive an incentive for power transfer. As shown in FIG. 3, since the advance period is a period in which the target power is changed, the allowable range of the target power is set wider than that of the execution period. Therefore, in the power transfer system 1 according to the embodiment, if the server device 30 determines that the target power in the execution period can be met by power transfer using the vehicles 50 that have accepted the DR request in the advance period, the server device 30 is configured to perform power transfer using the reserve vehicle 50 in the advance period. In this way, even if the target power in the execution period can be met by power transfer using the vehicles that have traded in advance, the server device 30 performs power transfer using the reserve vehicle 50 in the advance period, and can cause the reserve vehicle 50 to perform power transfer as scheduled.

[Procedure of processing executed in power transfer system]
Fig. 4 is a flowchart showing the procedure of processing executed in the electric power transfer system 1 according to the embodiment. Fig. 4 shows processing executed by the server device 30, processing executed by the user terminal 80, and processing executed by the EMS 60. In the following, steps are abbreviated as "S".

As shown in FIG. 4, the server device 30 determines whether or not a DR request has been received from the power company E1 or the upper aggregator E2 (S301). If the server device 30 has received a DR request (YES in S301), the server device 30 determines a combination of vehicles 50 that will make a DR request in response to the DR request from the power company E1 or the upper aggregator E2 (S302). At this time, the server device 30 picks up a number of vehicles 50 that is greater than the number of vehicles 50 required to satisfy the target power specified by the DR request from the power company E1 or the upper aggregator E2.

The server device 30 transmits a DR request signal including information to request a DR to the user terminal 80 of the user of the determined vehicle 50 (S303). The DR request signal includes, for example, information indicating the date and time (timing) for executing the DR request, information indicating whether the DR is an up-DR or down-DR, and information indicating the charging power/discharging power per vehicle 50 requested for the DR.

Meanwhile, the user terminal 80 determines whether or not a DR request signal has been received from the server device 30 in the VPP app (S801). When the user terminal 80 receives a DR request signal from the server device 30 (YES in S801), the user terminal 80 displays a screen on the display for confirming whether or not to accept the DR request (S802). The screen for confirming whether or not to accept the DR request includes, for example, an icon image of a button for inputting the intention to accept.

If the user terminal 80 has not received a DR request signal from the server device 30 (NO in S801), or after S802, the user terminal 80 determines whether the DR request has been accepted on a screen for confirming whether or not to accept the DR request (S803). If the DR request has been accepted (YES in S803), the user terminal 80 transmits an acceptance signal including information indicating that the DR request has been accepted to the server device 30 (S804).

If the DR request has not been approved (NO in S803), or after S804, the user terminal 80 returns the process to be executed to the calling higher-level process.

Meanwhile, the server device 30 determines whether or not an approval signal has been received from the user terminal 80 (S304). When the server device 30 receives an approval signal from the user terminal 80 (YES in S304), it adds information about the user of the user terminal 80 that sent the approval signal and the vehicle 50 to the DR request list (S305). At this time, the multiple vehicles 50 added to the DR request list include at least one vehicle 50 for satisfying the target power specified by the DR request from the power company E1 or the upper aggregator E2, as well as at least one spare vehicle 50. In other words, the server device 30 lists a larger number of vehicles 50 than the number for satisfying the target power related to the DR request.

If the server device 30 has not received an approval signal from the user terminal 80 (NO in S304), or after S305, the server device 30 determines whether the DR update timing has arrived (S306). If the DR update timing has arrived (YES in S306), the server device 30 determines whether the DR request has been updated (S307). That is, the server device 30 determines whether the target power for the execution period specified by the request from the power company E1 or the upper aggregator E2 has been updated. If the DR request has been updated (YES in S307), the server device 30 updates the DR request and updates the target power to be specified for the vehicle 50 that has approved the DR request (S308).

If the DR update timing has not arrived (NO in S306), if there is no DR request update (NO in S307), or after S308, the server device 30 determines whether the preliminary period has arrived (S309). If the preliminary period has arrived (YES in S309), the server device 30 checks whether at least one vehicle 50 that has accepted the DR request is ready to execute power transfer, and determines whether it is possible to meet the target power for the execution period using at least one vehicle 50 that is ready (S310).

In addition, in S310, the server device 30 may determine whether or not the at least one vehicle 50 that has accepted the DR request is ready to execute power transfer by receiving, from each EMS 60 corresponding to the at least one vehicle 50 that has accepted the DR request, a signal including information indicating that the vehicle 50 is already connected to the EVSE 40. Alternatively, the server device 30 may determine whether or not the at least one vehicle 50 that has accepted the DR request is ready to execute power transfer by receiving a signal including GPS information received by a navigation system installed in the at least one vehicle 50 that has accepted the DR request. Alternatively, the server device 30 may determine whether or not the at least one vehicle 50 that has accepted the DR request is ready to execute power transfer by receiving, from a user terminal 80 owned by a user of the at least one vehicle 50 that has accepted the DR request, a signal including information indicating whether or not the preparation for executing power transfer is completed.

When the server device 30 determines that it is possible to meet the target power for the execution period (YES in S310), it transmits a DR signal including information for executing a DR request to the EMS 60 corresponding to the EVSE 40 to which the spare vehicle 50 that is ready to receive and transmit power is connected (S311). The DR signal includes, for example, information commanding the execution of the DR request and information indicating the charging power/discharging power per vehicle 50 required by the DR.

In other words, the server device 30 determines that the target power can be met without using the spare vehicle 50 by transferring power using the vehicle 50 that has completed preparation, and controls the EMS 60 corresponding to the EVSE 40 to which the spare vehicle 50 is connected so that power transfer is performed using the spare vehicle 50 during the advance period.

On the other hand, the EMS 60 corresponding to the spare vehicle 50 determines whether or not it has received a DR signal from the server device 30 (S601). If the EMS 60 has received a DR signal from the server device 30 (YES in S601), it controls the EVSE 40 and the spare vehicle 50 to charge or discharge the battery 130 of the spare vehicle 50 in response to the DR signal (S602).

If EMS 60 has not received a DR signal from server device 30 (NO in S601), or after S602, it returns the process to be executed to the calling higher-level process.

On the other hand, if the preliminary period has not arrived (NO in S309), if it is determined that it is not possible to satisfy the target power in the execution period (NO in S310), or after S311, the server device 30 determines whether the DR request execution timing has arrived (S312). If the DR request execution timing has arrived (YES in S312), the server device 30 transmits a DR signal including information for executing the DR request to the EMS 60 corresponding to the EVSE 40 to which the vehicle 50 that is ready for power transfer is connected (S313). At this time, the server device 30 specifies the transfer power specified per vehicle by the DR signal so that the target power of power transfer is satisfied within the allowable range. For example, the server device 30 specifies the charging power per vehicle by the DR signal so that the target value of charging power is satisfied within the allowable range. Alternatively, the server device 30 specifies the discharge power per unit using the DR signal so that the target value of the discharge power is satisfied within the allowable range.

If the timing to execute the DR request has not arrived (NO in S312), or after S313, the server device 30 returns the process to be executed to the calling higher-level process.

Meanwhile, the EMS 60 corresponding to the vehicle 50 that accepted the DR request determines whether or not it has received a DR signal from the server device 30 (S601). If the EMS 60 has received a DR signal from the server device 30 (YES in S601), it controls the EVSE 40 and the vehicle 50 to charge or discharge the battery 130 of the vehicle 50 in response to the DR signal (S602).

For example, if the DR request indicated by the DR signal is an up DR, the EMS 60 transmits a signal to the EVSE 40 and the vehicle 50 to start charging the vehicle 50 according to the amount of power indicated by the DR signal. This starts charging the vehicle 50 so as to satisfy the specified charging target power.

In addition, if the DR request indicated by the DR signal is a lower DR, the EMS 60 transmits a signal to the EVSE 40 and the vehicle 50 to start discharging from the vehicle 50 according to the amount of power indicated by the DR signal. This starts discharging from the vehicle 50 so as to satisfy the specified target power for discharge.

If EMS 60 has not received a DR signal from server device 30 (NO in S601), or after S602, it returns to the higher-level process that called it.

In this way, according to the power transfer system 1, power transfer is scheduled with at least one spare vehicle 50 in addition to at least one vehicle 50 to satisfy the target power of power transfer. Therefore, even if the target power of power transfer during the execution period cannot be satisfied by at least one vehicle 50 with which a transaction has been made in advance, the target power of power transfer during the execution period can be satisfied using at least one spare vehicle 50. On the other hand, even if the target power during the execution period can be satisfied by power transfer using at least one vehicle with which a transaction has been made in advance, power transfer is performed using at least one spare vehicle 50 in the advance period, so that power transfer can be performed as scheduled with at least one spare vehicle 50.

The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is indicated by the claims rather than the description of the embodiments above, and is intended to include all modifications within the meaning and scope of the claims.

1 Power transfer system, 10, 20, 20A, 20B, 30, 30A, 30B Server device, 11 Power plant, 12 Power transmission and distribution equipment, 13 Smart meter, 31 Control device, 32 Storage device, 33 Communication device, 41 Control unit, 42 Charging cable, 43 Connector, 44 Power circuit, 50, 50A, 50B, 50C Vehicle, 80 User terminal, 110 Inlet, 120 Charger/discharger, 130 Battery, 180 Communication device, E1 Power company, E2 Upper aggregator, E3 Lower aggregator, PG Power system.

Claims (1)

An electric power transfer system for transferring electric power,
The power grid of electric power companies,
Multiple vehicles and
a server device that transfers the electric power between the electric power system and each of the plurality of vehicles;
The server device includes:
Among the plurality of vehicles, at least one vehicle is scheduled to exchange power in order to satisfy the target power of the power exchange, and at least one spare vehicle is scheduled to exchange power;
An electric power transfer system which, when it is determined that the target power for the execution period can be met by the electric power transfer using the at least one vehicle in a preliminary period prior to the execution period in which the electric power transfer is performed, performs the electric power transfer using the at least one spare vehicle in the preliminary period.

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