Power system, power control device, and power control method

Abstract

To provide a power system capable of suppressing fluctuation in sum of power of power control when a plurality of vehicles performs the power control.SOLUTION: When switching a target of external charge (power control) from a vehicle 50A (first power apparatus) to a vehicle 50B (second power apparatus), a server 30 (power control device) of a power system 1 performs gradual change switching control for switching the target of external charge by gradually changing a charge amount (charge power) in the external charge of each of the vehicle 50A and the vehicle 50B. When switching the target of external charge from the vehicle 50A to a vehicle 50D (third power apparatus), the server 30 performs instantaneous switching control for switching the target of external charge by instantaneously changing a charge amount (charge power) in external charge of the vehicle 50D into the amount corresponding to the charge amount (charge power) in the external charge of the vehicle 50A.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to a power system, a power control device, and a power control method. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2021-035135 (Patent Document 1) discloses a power system including a first vehicle, a second vehicle, and an external power source. The first vehicle and the second vehicle receive a supply of power from the external power source and perform external charging. Specifically, the target of external charging is switched from the first vehicle to the second vehicle using a relay system. At this time, the charging power of the first vehicle and the charging power of the second vehicle are each gradually changed. While the charging power of each vehicle is gradually changed, the sum of the charging powers of the external charging is kept constant. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-035135 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, as described above, when external charging is switched from the first vehicle to the second vehicle using a relay system, the charging power of the first vehicle and the charging power of the second vehicle are each gradually changed. However, Patent Document 1 does not take into consideration the possibility that the first vehicle may unexpectedly disconnect from external charging before the scheduled time. In this case, it may be difficult to compensate for the fluctuation in the sum of charging powers caused by the first vehicle's unexpected disconnection from external charging using the charging power of the second vehicle. This may result in a large fluctuation in the sum of charging powers for external charging. Therefore, there is a need for a power system, a power control device, and a power control method that can suppress fluctuations in the sum of external charging powers when multiple vehicles perform external charging (power control).

[0005] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide a power system, a power control device, and a power control method that are capable of suppressing fluctuations in the sum of power controlled when multiple vehicles perform external charging (power control). [Means for solving the problem]

[0006] A power system according to a first aspect of the present disclosure includes a first power device configured to perform power control during a first period, the power control including at least one of feeding power to a power grid or charging from the power grid, at least one second power device configured to perform power control during a second period following the first period, at least one third power device configured to perform power control when at least one of the first power device and the second power device leaves power control during the power control, and a power control device that controls the power control of each of the first power device, the second power device, and the third power device, wherein the power control device When switching the control target from a first power device to a second power device, gradual switching control is performed to switch the power control target by gradually changing the charging amount or power supply amount in the power control of each of the first power device and the second power device, and when switching the power control target from at least one of the first power device and the second power device to a third power device, immediate switching control is performed to switch the power control target by immediately changing the charging amount or power supply amount in the power control of the third power device to an amount corresponding to the charging amount or power supply amount in the power control of at least one of the first power device and the second power device.

[0007] In the power system according to the first aspect of the present disclosure, as described above, the target of power control is switched from the first power device to the second power device by performing gradual switching control, and the target of power control is switched from at least one of the first power device and the second power device to a third power device by performing immediate switching control. Thus, even if at least one of the first power device and the second power device unexpectedly leaves power control during power control, the power of the third power device can be immediately changed to quickly compensate for unexpected fluctuations in the sum of powers under power control due to the unexpected departure of at least one of the first power device and the second power device. As a result, fluctuations in the sum of powers under power control can be suppressed.

[0008] Furthermore, a difference may occur between the communication delay time between the first power device and the power control device and the communication delay time between the second power device and the power control device due to differences in the communication environment, etc. Therefore, when the power of each of the first power device and the second power device is changed immediately to switch the target of power control, the sum of the power controlled may suddenly fluctuate due to the difference in the communication delay time. Therefore, by performing gradual switching control when switching the target of power control between the first power device and the second power device, the sum of the power controlled can be changed gradually. As a result, fluctuations in the sum of the power controlled can be more effectively suppressed even when the communication delay occurs, compared to when the power of each of the first power device and the second power device is changed immediately.

[0009] In the power system according to the first aspect, the power control device preferably communicates with each of the first, second, and third electric power devices, acquires information regarding communication delay times between the first, second, and third electric power devices, and performs gradual switching control based on the communication delay times of the first and second electric power devices, and performs immediate switching control based on the communication delay time of the third vehicle. This configuration allows gradual switching control to be performed based on the difference between the communication delay times of the first and second electric power devices. As a result, when the target of power control is switched from the first to the second electric power device, the length of the period during which only one of the first and second electric power devices fluctuates can be easily adjusted. Furthermore, immediate switching control can be performed based on the communication delay time of the third electric power device. As a result, when the target of power control switches from at least one of the first and second power devices to the third power device, the length of the period during which power control is not performed in both the at least one of the first and second power devices and the third power device can be easily adjusted.

[0010] In this case, preferably, a plurality of second power devices and a plurality of third power devices are provided, and the power control device selects, from the plurality of second power devices, the second power device having the smallest difference between the communication delay time of the second power device and the communication delay time of the first power device as the target of gradual switching control, and selects, from the plurality of third power devices, the third power device having the smallest communication delay time as the target of immediate switching control. With this configuration, when the target of power control switches from the first power device to the second power device, the length of the period during which only one of the first power device and the second power device fluctuates can be minimized. Furthermore, when the target of power control switches from at least one of the first power device and the second power device to the third power device, the length of the period during which power control is not performed in both the at least one of the first power device and the second power device and the third power device can be minimized.

[0011] In the power system according to the first aspect, the first period preferably includes a predetermined time a predetermined time before a scheduled end time of the first period, and the power control device determines to perform gradual switching control when power control by the first power device is being performed until the predetermined time, and determines to perform immediate switching control when the first power device is released from power control before the predetermined time. With this configuration, it is possible to determine whether to perform gradual switching control or immediate switching control before the scheduled end time of the first period.

[0012] In this case, preferably, the power control device communicates with each of the first, second, and third power devices and acquires information regarding a communication delay time between the first, second, and third power devices, and the predetermined time is equal to or longer than the longer of the communication delay time of the first power device and the communication delay time of the second power device. This configuration can prevent the first period from ending before the first or second power device with the longer communication delay time starts power control. As a result, the period during which the power of the first power device is gradually changed in power control and the period during which the power of the second power device is gradually changed in power control can be more reliably overlapped.

[0013] In the power system according to the first aspect, preferably, of the first, second, and third power devices, at least the first power device includes an electric vehicle. Here, unlike a power storage device or the like, an electric vehicle is capable of moving. Therefore, the first power device (electric vehicle) can move during the power control of the first period, and therefore there is a relatively high possibility that the first power device (electric vehicle) will exit the power control during the power control. Therefore, if immediate switching control is possible between the first and third power devices, fluctuations in the sum of power control can be more effectively suppressed.

[0014] In the power system according to the first aspect, preferably, of the second and third electric power devices, at least the second electric power device includes an electric vehicle. With this configuration, similarly to the above, when immediate switching control is possible between the second and third electric power devices, fluctuations in the sum of power control can be more effectively suppressed.

[0015] A power control device according to a second aspect of the present disclosure is a power control device that controls power control of a first power device capable of power control including at least one of feeding power to a power grid or charging from the power grid, a second power device capable of power control, and a third power device capable of power control, wherein the first power device is set to be power controlled in a first period, the second power device is set to be power controlled in a second period following the first period, and the third power device is set to be power controlled when at least one of the first power device and the second power device leaves power control during the power control. When the target of power control is switched from a first power device to a second power device, gradual switching control is performed to switch the target of power control by gradually changing both the charging amount or the power supply amount in the power control of each of the first power device and the second power device, and when the target of power control is switched from at least one of the first power device and the second power device to a third power device, immediate switching control is performed to switch the target of power control by immediately changing the charging amount or the power supply amount in the power control of the third power device to an amount corresponding to the charging amount or the power supply amount in the power control of at least one of the first power device and the second power device.

[0016] In a power control device according to a second aspect of the present disclosure, as described above, gradual switching control is performed to switch the target of power control from the first power device to the second power device, and immediate switching control is performed to switch the target of power control from the first power device to the third power device. This allows for the provision of a power control device that can suppress fluctuations in the sum of power controlled by the third power device even if at least one of the first power device and the second power device unexpectedly leaves power control during power control.

[0017] A power control method according to a third aspect of the present disclosure is a power control method for controlling the power control of a first power device capable of power control including at least one of feeding power to a power grid or charging from the power grid, at least one second power device capable of power control, and at least one third power device capable of power control, wherein the first power device is set to be power controlled in a first period, the second power device is set to be power controlled in a second period after the first period, and the third power device is set to be power controlled when at least one of the first power device and the second power device leaves the power control during the power control, the method comprising: a gradual switching step for switching the target of power control by gradually changing both the charge amount or the power supply amount in the power control of each of the first power device and the second power device; and an immediate switching step for switching the target of power control by immediately changing the charge amount or the power supply amount in the power control of the third power device to an amount corresponding to the charge amount or the power supply amount in the power control of at least one of the first power device and the second power device.

[0018] In the power control method according to the third aspect of the present disclosure, as described above, the gradual switching step switches the target of power control from the first power device to the second power device, and the immediate switching step switches the target of power control from the first power device to the third power device. Thus, even if at least one of the first power device and the second power device unexpectedly leaves power control during power control, the power of the third power device can be immediately changed to quickly compensate for unexpected fluctuations in the sum of powers under power control due to the unexpected departure of at least one of the first power device and the second power device. As a result, a power control method capable of suppressing fluctuations in the sum of powers under power control can be provided. [Effects of the Invention]

[0019] According to the present disclosure, when a plurality of vehicles perform power control, fluctuations in the sum of the powers controlled can be suppressed. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a diagram illustrating a detailed configuration of a vehicle according to an embodiment. [Figure 2] FIG. 1 is a diagram illustrating a configuration of a VGI system (power system) according to an embodiment. [Figure 3] FIG. 1 illustrates a plurality of vehicles and a plurality of EVSEs managed by a VGI system (electric power system) according to one embodiment. [Figure 4] FIG. 10 is a diagram illustrating gradual change switching control of a server according to an embodiment. [Figure 5] FIG. 10 is a diagram illustrating immediate switching control of a server in period A according to an embodiment. [Figure 6] FIG. 10 is a diagram illustrating the maximum communication delay time between a server and each vehicle according to an embodiment. [Figure 7] FIG. 10 is a flow diagram illustrating a power control method for a server during external charging according to an embodiment. [Figure 8] FIG. 10 is a flowchart illustrating a power control method when a server is externally powered according to a modified example of an embodiment. [Figure 9]FIG. 10 is a diagram illustrating immediate switching control of a server in a period B according to a modified example of an embodiment. [Figure 10] FIG. 10 is a diagram illustrating an example in which gradual change switching control is performed between groups each made up of a plurality of vehicles. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0022] The power system according to this embodiment includes multiple vehicles. The multiple vehicles in the power system may have different configurations, but in this embodiment, they have the same configuration. Hereinafter, unless otherwise specified, each of the multiple vehicles included in the power system will be referred to as a "vehicle 50," and each of the multiple charging facilities included in the power system will be referred to as an "EVSE 40." EVSE stands for electric vehicle supply equipment.

[0023] FIG. 1 is a diagram showing the configuration of a vehicle according to this embodiment. Referring to FIG. 1, vehicle 50 is an electric vehicle equipped with a battery 130 that stores power for driving. Battery 130 includes a secondary battery such as a lithium-ion battery or a nickel-metal hydride battery. In this embodiment, a battery pack including a plurality of lithium-ion batteries is used as the secondary battery. The battery pack is configured by electrically connecting a plurality of unit cells (generally also referred to as "cells") to each other. Note that other power storage devices such as an electric double layer capacitor may be used instead of the secondary battery.

[0024] The vehicle 50 includes an electronic control unit (hereinafter referred to as "ECU (Electronic Control Unit)") 150. The vehicle 50 is capable of power control, including power supply to a power grid PG (external power supply) described below and charging from the power grid PG (external charging). The ECU 150 is configured to control charging and discharging of the battery 130. The ECU 150 is also configured to control communication between the vehicle 50 and the outside. The vehicle 50 may be an electric vehicle (BEV: Battery Electrical Vehicle) that can run using only the power stored in the battery 130, or may be a plug-in hybrid vehicle (PHEV) that can run using both the power stored in the battery 130 and the output of an engine (not shown). Note that, hereinafter, the external power supply and external charging may be collectively referred to as "power control."

[0025] The vehicle 50 can receive power from the EVSE 40 to charge the battery 130. The vehicle 50 includes an inlet 110 and a charger / discharger 120 that are compatible with the power supply method of the EVSE 40.

[0026] A cable 42 is connected to the EVSE 40. A connector 43 of the cable 42 connected to the EVSE 40 is connected to an inlet 110 of the vehicle 50, thereby electrically connecting the EVSE 40 and the vehicle 50. This enables power to be exchanged between the EVSE 40 and the vehicle 50 via the cable 42.

[0027] The charger / discharger 120 is located between the inlet 110 and the battery 130. The charger / discharger 120 includes a relay that switches between connection and disconnection of the power path from the inlet 110 to the battery 130, and a power conversion circuit (e.g., a bidirectional converter) (neither of which is shown).

[0028] The ECU 150 includes a processor 151, a RAM (Random Access Memory) 152, a storage device 153, and a timer 154. The processor 151 includes, for example, a CPU (Central Processing Unit). The RAM 152 includes a working memory that temporarily stores data processed by the processor 151. The storage device 153 is configured to be able to save stored information. In addition to programs, the storage device 153 also stores information used by the programs (for example, maps, formulas, and various parameters). In this embodiment, the processor 151 executes the programs stored in the storage device 153, thereby performing various controls in the ECU 150. The timer 154 notifies the processor 151 of the arrival of a set time. When the time set in the timer 154 arrives, the timer 154 transmits a signal to the processor 151 informing the processor 151 of this fact.

[0029] The vehicle 50 further includes a traveling drive unit 140, a communication device 160, and drive wheels W. The traveling drive unit 140 includes a PCU (Power Control Unit) and an MG (Motor Generator), not shown, and is configured to run the vehicle 50 using the electric power stored in the battery 130.

[0030] The communication device 160 includes various communication I / Fs (interfaces). The ECU 150 performs wireless communication with a communication device outside the vehicle 50 through the communication device 160. The communication device 160 may be configured to be capable of inter-vehicle communication.

[0031] In recent years, the power system, which relies on large-scale power plants (centralized energy resources) owned by electric power companies, has been reconsidered, and efforts are underway to build a system that utilizes the energy resources owned by individual consumers (hereinafter referred to as "DSR (Demand Side Resources)") in the power system.DSR functions as a distributed energy resource (hereinafter referred to as "DER (Distributed Energy Resources)").

[0032] VPP (Virtual Power Plant) has been proposed as a mechanism for utilizing DSR in the power system. In a VPP, the electric utility that bundles DERs and provides energy management services is called an "aggregator." By collaborating with an aggregator, for example, electric power companies can adjust the balance of power supply and demand through demand response (hereinafter also referred to as "DR").

[0033] DR is a method of adjusting the balance between supply and demand of electricity by issuing a specific request to each consumer using a demand response signal (hereinafter also referred to as "DR signal"). DR signals are broadly divided into two types: DR signals that request a reduction in electricity demand or a reverse flow (hereinafter also referred to as "down DR signal"), and DR signals that request an increase in electricity demand (hereinafter also referred to as "up DR signal").

[0034] FIG. 2 is a diagram illustrating a schematic configuration of a power system according to this embodiment. The VGI (Vehicle Grid Integration) system 1 illustrated in FIG. 2 corresponds to an example of the "power system" according to the present disclosure. Although FIG. 2 illustrates only one vehicle, one EVSE, and one aggregator server, the VGI system 1 includes multiple vehicles, multiple EVSEs, and multiple aggregator servers. While FIG. 2 illustrates a home EVSE, the VGI system 1 may also include a public EVSE that is available to an unspecified number of users.

[0035] 2, the VGI system 1 includes an electricity transmission and distribution company server 10 (hereinafter also simply referred to as "server 10"), a smart meter 11, an aggregator server 30 (hereinafter also simply referred to as "server 30"), an EVSE 40, a vehicle 50, a HEMS-GW (Home Energy Management System-GateWay) 60, a data center 70, a mobile terminal 80, and a power system PG. In this embodiment, the mobile terminal 80 includes a smartphone, tablet, or the like equipped with a touch panel display.

[0036] The server 10 belongs to an electricity transmission and distribution company. In this embodiment, the electric power company serves as both a power generation company and an electricity transmission and distribution company, and also corresponds to a system operator that operates the electric power system PG.

[0037] Identification information for identifying each smart meter (hereinafter also referred to as a "meter ID") is assigned to each smart meter. The server 10 manages the measurement values ​​of each smart meter by distinguishing them by the meter ID.

[0038] In the VGI system 1, each aggregator is assigned an identification (ID) to identify it. The server 10 manages information about each aggregator by distinguishing it by the aggregator's ID. The aggregator provides an energy management service by aggregating the amount of power controlled by consumers within its jurisdiction. The aggregator can control the amount of power by requesting power leveling from each consumer via a DR signal.

[0039] The server 30 belongs to the aggregator. The server 30 includes a control device 31, a storage device 32, and a communication device 33. The control device 31 includes a processor, performs predetermined information processing, and controls the communication device 33. The storage device 32 can store various types of information. The communication device 33 includes various communication I / Fs. The control device 31 communicates with the outside world through the communication device 33. In the VGI system 1, the DSRs managed by the aggregator (server 30) are electric vehicles. Consumers control the amount of power using electric vehicles. Identification information (hereinafter also referred to as "vehicle ID") for identifying each vehicle 50 included in the VGI system 1 is assigned to each vehicle 50. The server 30 manages the information for each vehicle 50 by distinguishing them by vehicle ID.

[0040] The data center 70 includes a control device 71, a storage device 72, and a communication device 73. The control device 71 includes a processor, performs predetermined information processing, and controls the communication device 73. The storage device 72 is capable of storing various types of information. The communication device 73 includes various communication I / Fs. The control device 71 communicates with the outside world through the communication device 73. Identification information for identifying the mobile terminal (hereinafter also referred to as a "terminal ID") is assigned to each mobile terminal. The data center 70 manages information for each mobile terminal by distinguishing them by the terminal ID. The terminal ID also functions as information for identifying the user (user ID).

[0041] The mobile terminal 80 exchanges information with each of the HEMS-GW 60 and the data center 70 through a predetermined application. The mobile terminal 80 communicates wirelessly with each of the HEMS-GW 60 and the data center 70, for example, via the Internet. A user can send information indicating the user's status and schedule to the data center 70 by operating the mobile terminal 80. An example of the information indicating the user's status is information indicating whether the user is in a state where they can respond to DR. An example of the information indicating the user's schedule is the time a POV (Personal Owned Vehicle) departs from home, or an operation plan for a MaaS (Mobility as a Service) vehicle. The data center 70 stores the information received from the mobile terminal 80, distinguishing it by terminal ID.

[0042] The servers 10 and 30 can communicate with each other, for example, via a VPN (Virtual Private Network). Each of the servers 10 and 30 can obtain electricity market information (for example, information about electricity trading) via the Internet, for example. The server 30 and the data center 70 can communicate with each other, for example, via the Internet. The server 30 can obtain information about users from the data center 70. Each of the server 30 and the data center 70 and the HEMS-GW 60 are configured to be able to communicate with each other, for example, via the Internet. In this embodiment, no communication is performed between the server 30 and the EVSE 40, but the server 30 and the EVSE 40 may be configured to be able to communicate with each other.

[0043] The server 30 sequentially acquires and stores information indicating the status of each vehicle 50 within its jurisdiction (e.g., vehicle location, cable connection status, battery status, charging (power supply) schedule, charging (power supply) conditions, driving schedule, and driving conditions). The cable connection status is information indicating whether the cable connector is connected to the inlet 110. The battery status is information indicating the value of the SOC (State Of Charge) of the battery 130 and whether the battery 130 is being charged. The charging (power supply) schedule is information indicating the start time and end time of a planned external charging (external power supply). The charging (power supply) conditions may be the conditions of a planned external charging (external power supply) (e.g., charging power and power supply power) or the conditions of a currently executing charging (power supply) (e.g., charging (power supply) power and remaining charging (power supply) time). The driving schedule is information indicating the start time and end time of a planned drive. The driving conditions may be the conditions of a planned drive (for example, a driving route and a driving distance), or the conditions of a current drive (for example, a driving speed and a remaining driving distance).

[0044] The server 10 performs power leveling using DR (Demand Response). When performing power leveling, the server 10 first transmits a signal (hereinafter also referred to as a "DR participation request") to each aggregator server (including the server 30) requesting participation in DR. The DR participation request includes the area subject to the DR, the type of DR (for example, downward DR or upward DR), and the DR period. When the server 30 receives the DR participation request from the server 10, the server 30 is configured to calculate the DR possible amount (i.e., the amount of power that can be adjusted according to DR) and transmit it to the server 10. The server 30 can calculate the DR possible amount based on, for example, the total DR capacity (i.e., the capacity that can accommodate DR) of each consumer within its jurisdiction.

[0045] The server 10 determines the DR amount for each aggregator (i.e., the amount of power adjustment to be requested from the aggregator) based on the DR possible amount received from each aggregator server, and transmits a signal (hereinafter also referred to as a "DR execution instruction") instructing each aggregator server (including the server 30) to execute DR. The DR execution instruction includes the area subject to the DR, the type of DR (e.g., down DR or up DR), the DR amount for the aggregator, and the DR period. Upon receiving the DR execution instruction, the server 30 allocates a DR amount to each DR-compatible vehicle 50 within its jurisdiction, creates a DR signal for each vehicle 50, and transmits the DR signal to each vehicle 50. The DR signal includes the type of DR (e.g., down DR or up DR), the DR amount for the vehicle 50, and the DR period.

[0046] ECU 150 is configured to receive a DR signal from outside the vehicle via communication device 160. When ECU 150 receives the DR signal, the user of vehicle 50 can contribute to power leveling by using EVSE 40 and vehicle 50 to charge or supply power in accordance with the DR signal.

[0047] 2 is parked in a parking space of a residence (for example, a user's home) and is electrically connected to an outdoor EVSE 40 via a cable 42. When a connector 43 of the cable 42 connected to the EVSE 40 is connected to an inlet 110 of the vehicle 50, communication between the vehicle 50 and the EVSE 40 becomes possible, and power control (external charging and external power supply) becomes possible through a power supply circuit 41.

[0048] The power supply circuit 41 is connected to a power grid PG provided by a power company via a smart meter 11. The smart meter 11 is configured to measure the amount of power supplied from the EVSE 40 to the vehicle 50.

[0049] Fig. 3 is a diagram showing an external power source, multiple charging facilities, and multiple vehicles included in the power system according to this embodiment. Referring to Fig. 3, VGI system 1 includes EVSEs 40A-40I, vehicles 50A-50E, and a power grid PG that supplies power to each of the EVSEs 40A-40I. Vehicles 50A-50E are equipped with batteries 130A-130E, respectively. Each of vehicles 50A-50E is configured to be electrically connectable to the power grid PG via one of EVSEs 40A-40I. Power control of each of vehicles 50A-50E is controlled by server 30.

[0050] Here, vehicles are generally set to perform power control (external charging and external power feeding) at scheduled times planned in advance during the DR period. When the power control of a vehicle is completed as scheduled, power control by another vehicle begins, thereby keeping the sum of charging (power feeding) power by multiple vehicles constant. However, power control may end unexpectedly before the scheduled time due to reasons such as a vehicle driving away during power control or the battery becoming fully charged earlier than planned. In this case, it is difficult for the power control by the other vehicle, whose power control time is set in advance, to compensate for the impact on the sum of the power. Therefore, it is desirable to suppress fluctuations in the sum of charging (power feeding) power when multiple vehicles perform power control.

[0051] In this embodiment, vehicle 50A is set to be externally charged during period A (times t0 to t4) (see FIG. 4). Vehicles 50B and 50C are set to be externally charged during period B (times t4 to t7) (see FIG. 4) that follows period A. Period B is the period following (immediately following) period A. Periods A and B may be included in the same DR period, or may be included in successive DR periods. Vehicle 50A is an example of a "first power device" in the present disclosure. Vehicles 50B and 50C are examples of a "second power device" in the present disclosure. Period A and period B are examples of a "first period" and a "second period," respectively, in the present disclosure.

[0052] The number of vehicles 50 that are set to be externally charged during period B may be one, or may be three or more.

[0053] In the present embodiment, each of vehicles 50D and 50E is configured to be externally charged when vehicle 50A is disconnected from external charging during external charging. In other words, each of vehicles 50D and 50E is configured to be externally charged when vehicle 50A is disconnected from external charging earlier than the pre-planned timing. Note that each of vehicles 50D and 50E may be a vehicle for which power control is scheduled to be performed in a period that is even later than period A and period B. In this case, each of vehicles 50D and 50E is a vehicle that is set to be capable of power control before the scheduled power control in preparation for the unexpected disconnection of vehicle A. Note that vehicles 50D and 50E are examples of a "third power device" in the present disclosure.

[0054] Furthermore, the number of vehicles 50 that are set to undergo external charging when vehicle 50A leaves external charging earlier than the pre-planned timing may be one, or may be three or more. Note that in the present embodiment, an example has been shown in which the vehicles (50B, 50C) that undergo external charging when vehicle 50A leaves external charging as scheduled and the vehicles (50D, 50E) that undergo external charging when vehicle 50A leaves external charging at a timing different from that scheduled are different from each other, but this is not limited to this. The vehicles (50B, 50C) that undergo external charging when vehicle 50A leaves external charging as scheduled may be set to undergo external charging when the departure occurs at a timing different from that scheduled.

[0055] Here, in this embodiment, as shown in Fig. 4, when the target of external charging is switched from vehicle 50A to vehicle 50B, server 30 (control device 31) performs gradual switching control to switch the target of external charging by gradually changing the charge amount (charging power) in external charging of each of vehicle 50A and vehicle 50B. On the other hand, as shown in Fig. 5, when the target of external charging is switched from vehicle 50A to vehicle 50D, server 30 (control device 31) performs immediate switching control to switch the target of external charging by immediately changing the charge amount (charging power) in external charging of vehicle 50D to an amount corresponding to the charge amount (charging power) in external charging of vehicle 50A.

[0056] The server 30 (control device 31) transmits a first control command to the vehicle 50A to control the charging power of the vehicle 50A. The server 30 also transmits a second control command to the vehicle 50B to control the charging power of the vehicle 50B. In the example shown in FIG. 4, when performing gradual change switching control, the server 30 reduces the charging power of the first control command from 3 kW to 0 kW at a constant rate over a predetermined time (e.g., 10 to 15 minutes). When performing gradual change switching control, the server 30 also increases the charging power of the second control command from 0 kW to 3 kW at a constant rate over a predetermined time (e.g., 10 to 15 minutes). The server 30 starts to reduce the charging power of the first control command and increase the charging power of the second control command at the same timing (time t1 in FIG. 4). The slopes of the first control command and the second control command during gradual change switching control have the same absolute value. The first and second control commands may be transmitted to EVSE 40 connected to vehicle 50A and vehicle 50B, respectively. Time t1 is an example of a "predetermined time" in the present disclosure.

[0057] The server 30 (control device 31) transmits a third control command to the vehicle 50D to control the charging power of the vehicle 50D. In the example shown in FIG. 5, the vehicle 50A suddenly disconnects from external charging, and the charging power of the vehicle 50A immediately drops from 3 kW to 0 kW. When the communication device 33 (see FIG. 2) acquires information indicating that the charging power of the vehicle 50A has dropped (become 0) before the scheduled end time of external charging of the vehicle 50A, the server 30 (control device 31) determines that the vehicle 50A has unexpectedly disconnected from external charging. In this case, the server 30 performs immediate switching control by immediately (for example, in a few seconds) increasing the charging power of the third control command from 0 kW to 3 kW.

[0058] When performing immediate switching control, the server 30 (control device 31) controls the upper limit current value of the EVSE 40 to be greater than the upper limit current value during gradual switching control. This enables a rapid rise in charging power.

[0059] Furthermore, a predetermined communication delay time occurs between each of the vehicles 50A-50E and the server 30. The communication delay time depends on the specifications of the communication device 160 installed in each vehicle 50, the communication environment at the location where each EVSE 40 is located, and the like. The server 30 acquires information regarding the communication delay time of each of the vehicles 50A-50E. In this embodiment, the information regarding the communication delay time includes a maximum communication delay time. When the vehicle 50 is connected to the EVSE 40, the server 30 (control device 31) may acquire (calculate) the maximum communication delay time based on information about the vehicle 50 and information about the EVSE 40 connected to the vehicle 50.

[0060] As shown in Fig. 6, in this embodiment, the maximum communication delay time of vehicle 50A (ΔTa in Fig. 4) and the maximum communication delay time of vehicle 50D (ΔTd in Fig. 5) are each assumed to be 0.5 minutes. Also, the maximum communication delay time of vehicle 50B (ΔTb in Fig. 4) and the maximum communication delay time of vehicle 50E are each assumed to be 1 minute. Also, the maximum communication delay time of vehicle 50C is assumed to be 1.5 minutes.

[0061] In this embodiment, the server 30 (control device 31) performs gradual-change switching control based on the maximum communication delay time of the vehicle 50A and the maximum communication delay times of the vehicles 50B and 50C. Specifically, the server 30 performs gradual-change switching control based on the magnitude relationship between the difference between the maximum communication delay time of the vehicle 50A and the maximum communication delay time of the vehicle 50B, and the difference between the maximum communication delay time of the vehicle 50A and the maximum communication delay time of the vehicle 50C.

[0062] Here, the difference between the maximum communication delay time of vehicle 50A and the maximum communication delay time of vehicle 50B (1 minute - 0.5 minutes = 0.5 minutes) is smaller than the difference between the maximum communication delay time of vehicle 50A and the maximum communication delay time of vehicle 50C (1.5 minutes - 0.5 minutes = 1 minute). Therefore, server 30 (control device 31) selects vehicle 50B as the target of gradual change switching control. If the difference between the maximum communication delay time of vehicle 50A and the maximum communication delay time of vehicle 50C is smaller than the difference between the maximum communication delay time of vehicle 50A and the maximum communication delay time of vehicle 50B, vehicle 50C is selected as the target of gradual change switching control. Note that server 30 performs gradual change switching control based on the magnitude relationship between the absolute values ​​of the above differences.

[0063] 4, the sum of the charging power of vehicle A and the charging power of vehicle B (total charging power) decreases between time t2 and time t3 due to the magnitude of the difference (ΔTb-ΔTa) between the maximum communication delay time of vehicle 50A and the maximum communication delay time of vehicle 50B. Therefore, the smaller the difference (ΔTb-ΔTa), the smaller the amount of decrease in the total charging power can be.

[0064] Furthermore, between time t3 and time t4, the decrease in the charging power of vehicle 50A and the increase in the charging power of vehicle 50B are equal, so the total charging power does not change and remains constant at a predetermined value. The total charging power, which decreased between time t2 and time t3, increases to 3 kW between time t5 and time t6 after the decrease in the charging power of vehicle 50A stops. Furthermore, the total charging power is maintained at 3 kW from time t6 onwards after the increase in the charging power of vehicle 50B stops.

[0065] Meanwhile, the server 30 (control device 31) performs immediate switching control based on the maximum communication delay times of the vehicles 50D and 50E. Specifically, the server 30 performs immediate switching control based on the relationship in magnitude between the maximum communication delay time of the vehicle 50D and the maximum communication delay time of the vehicle 50E.

[0066] Here, the maximum communication delay time of vehicle 50D (0.5 minutes) is shorter than the maximum communication delay time of vehicle 50E (1 minute). Therefore, server 30 (control device 31) selects vehicle 50D as a target for immediate switching control. If the maximum communication delay time of vehicle 50E is shorter than the maximum communication delay time of vehicle 50D, server 30 selects vehicle 50E as a target for immediate switching control.

[0067] As shown in FIG. 5, the sum of the charging power of vehicle 50A and the charging power of vehicle 50D (total charging power) decreases between time t11 and time t12 due to the magnitude of the maximum communication delay time (ΔTd) of vehicle 50D. Therefore, the shorter the maximum communication delay time (ΔTd) of vehicle 50D, the shorter the period during which the total charging power decreases. Note that the total charging power that decreased at time t11 immediately increases to 3 kW at time t12 as the charging power of vehicle 50D starts to rise. Furthermore, the total charging power remains at 3 kW after time t12, after the immediate rise of the charging power of vehicle 50D is completed.

[0068] 4, in the present embodiment, the server 30 (control device 31) determines to perform gradual change switching control when external charging by the vehicle 50A is being performed until time t1. Specifically, the server 30 changes the gradual change switching determination (signal) from the OFF state to the ON state when the vehicle 50A has not been disconnected from external charging until time t1. When the gradual change switching determination (signal) is changed from the OFF state to the ON state, the server 30 determines that the target of power control (external charging) can be switched from the vehicle 50A to the vehicle 50B or the vehicle 50C by the gradual change switching control.

[0069] 5, in the present embodiment, if vehicle 50A leaves external charging before time t1, it is determined that immediate switching control be performed. Specifically, if vehicle 50A leaves external charging before time t1, server 30 (control device 31) changes the immediate switching determination (signal) from the OFF state to the ON state. As the immediate switching determination (signal) is changed from the OFF state to the ON state, server 30 determines that the target of power control (external charging) can be switched from vehicle 50A to vehicle 50D or vehicle 50E by immediate switching control.

[0070] Furthermore, time t1 is a time Δτ (see FIG. 4) before time t4, which is the scheduled end time of period A. The time Δτ is equal to or greater than the larger (ΔTb) of the maximum communication delay time (ΔTa) of vehicle 50A and the maximum communication delay time (ΔTb) of vehicle 50B. Preferably, the time Δτ is equal to or greater than the largest of ΔTa, ΔTb, and the maximum communication delay time of vehicle 50C. The time Δτ is an example of a "predetermined time" in the present disclosure.

[0071] The time Δτ is, for example, about 30 minutes. That is, in this embodiment, the time Δτ is 10 times or more the longest of ΔTa, ΔTb, and the maximum communication delay time of the vehicle 50C. The length of the time Δτ is not limited to the above example.

[0072] Furthermore, the gradient of the charging power of vehicle 50A and the gradient of the charging power of vehicle 50B during the gradual change switching control shown in FIG. 4 are preset fixed values. The fixed values ​​are preset so that the time ΔTs during which the charging power is changed is equal to or greater than the longer of the maximum communication delay time (ΔTa) of vehicle 50A and the maximum communication delay time (ΔTb) of vehicle 50B. Preferably, the fixed values ​​are preset so that the time ΔTs is equal to or greater than the largest of ΔTa, ΔTb, and the maximum communication delay time of vehicle 50C. This makes it possible to reliably overlap the timing at which the charging power is changed between vehicles 50 that are the target of the gradual change switching control. The time ΔTs is, for example, approximately 10 to 15 minutes.

[0073] The gradient of the charging power of vehicle 50A (50B) during gradual change switching control may be set based on a delay time due to control response. The delay due to control response means the time from when vehicle 50 receives a control signal for charging power until the charging power changes based on the received control signal.

[0074] (Power control method) Next, a power control method by the server 30 (control device 31) in this embodiment will be described with reference to Fig. 7. Fig. 7 shows a flow from when the server 30 receives a DR execution instruction (external charging request) from the server 10 until when the target of external charging is switched from the vehicle 50A to the next vehicle 50.

[0075] First, in step S1, the server 30 acquires an external charging schedule for each of the vehicles 50A to 50E. The schedule may be acquired from each vehicle 50, or may be set by the server 30 itself based on the travel schedule of each vehicle 50, etc.

[0076] Next, in step S2, the server 30 acquires information regarding the communication delay time (maximum communication delay time) between the server 30 and each of the vehicles 50A to 50E. The server 30 may calculate the magnitude of the maximum communication delay time based on the specifications of the communication device 160 of each of the vehicles 50A to 50E, the communication environment of the location of the EVSE 40 connected to each of the vehicles 50A to 50E, and the like.

[0077] Next, in step S3, server 30 starts controlling external charging of vehicle 50A. Specifically, server 30 starts controlling external charging during period A (see FIG. 4) based on the schedule acquired in step S1.

[0078] Next, in step S4, the server 30 determines whether the vehicle 50A has disconnected from external charging by time t1. The communication device 33 acquires, through communication, information relating to whether the vehicle 50A has disconnected from external charging by time t1. If it is determined that the vehicle 50A has disconnected from external charging by time t1 (Yes in S4), the process proceeds to step S5. If it is determined that the vehicle 50A has not disconnected from external charging by time t1 (No in S4), the process proceeds to step S6.

[0079] In step S5, server 30 switches the target of external charging from vehicle 50A to vehicle 50D or vehicle 50E through immediate switching control. This immediate switching control is performed when vehicle 50A is disconnected from external charging. As described above, server 30 selects vehicle 50D, which has the shortest maximum communication delay time, as the target of external charging between vehicle 50D and vehicle 50E. Step S5 is an example of an "immediate switching step" of the present disclosure.

[0080] Meanwhile, in step S6, server 30 switches the target of external charging from vehicle 50A to vehicle 50B or vehicle 50C through gradual change switching control. This gradual change switching control starts at time t1. As described above, server 30 selects, as the target of external charging, vehicle 50B, which corresponds to the maximum communication delay time that is the smallest difference from the maximum communication delay time of vehicle 50A, from among vehicle 50B and vehicle 50C. Step S6 is an example of a "gradual change switching step" of the present disclosure.

[0081] In step S7, server 30 performs (continues) external charging of vehicle 50D selected in step S5.

[0082] In step S8, server 30 performs (continues) external charging of vehicle 50B selected in step S6.

[0083] As described above, in this embodiment, the server 30 (control device 31) performs gradual change switching control to switch the target of power control by gradually changing the charge amount (charging power) in external charging of each of the vehicles 50A and 50B. Also, it performs immediate switching control to switch the target of external charging by immediately changing the charge amount (charging power) in external charging of the vehicle 50D to an amount corresponding to the charge amount (charging power) in external charging of the vehicle 50A.

[0084] The immediate switching control described above makes it possible to quickly suppress fluctuations in the total charging power due to vehicle 50A unexpectedly disconnecting from external charging by immediately increasing the charging power of vehicle 50D. Furthermore, the gradual switching control described above makes it possible to suppress abrupt fluctuations in the total charging power even when there is a difference between the maximum communication delay time of vehicle 50A and the maximum communication delay time of vehicle 50D.

[0085] Furthermore, while the above embodiment illustrates control for switching the vehicle 50 that is the target of external charging, the present disclosure is not limited to this. As shown in Fig. 8, the gradual switching control and immediate switching control of the above embodiment may also be performed when switching the vehicle 50 that is the target of external power feeding. In the example shown in Fig. 8, steps S11 and S13 to S18 are performed instead of steps S1 and S3 to S8 in Fig. 7, respectively. The controls in steps S11 and S13 to S18 are simply the same as steps S1 and S3 to S8, respectively, except that the external charging-related aspects of the controls are replaced with external power feeding, and therefore will not be described in detail.

[0086] In the above embodiment, an example has been described in which immediate switching control is performed when vehicle 50A unexpectedly (unplannedly) leaves power control (external charging), but the present disclosure is not limited to this. As shown in Fig. 9, immediate switching control may also be performed when vehicle 50B unexpectedly leaves power control (external charging).

[0087] 9, the server 30 (control device 31) determines to perform immediate switching control when the vehicle 50B is disconnected from external charging before time t23 in period B. Time t23 is a time Δτ before time t7, which is the scheduled end time of period B. The details of the immediate switching control are the same as those of the above embodiment, and therefore will not be described in detail again.

[0088] Note that only one of the immediate switching control in period A and the immediate switching control in period B may be performed.

[0089] In addition, although the above embodiment shows an example in which the target of power control is switched between vehicles, the present disclosure is not limited to this. In addition to vehicles, the target of power control may be switched between power devices other than vehicles (for example, a power storage device, an air conditioner, a water heater, etc.).

[0090] Furthermore, in the above embodiment, an example has been described in which the charging power is gradually changed for each vehicle 50 during gradual change switching control, but the present disclosure is not limited to this. For example, the total charging power of multiple vehicles 50 may be gradually changed. For example, in the example shown in Fig. 10, external charging is gradually stopped (started) for every 100 vehicles 50, thereby performing gradual change switching control between different groups of 300 vehicles 50.

[0091] In the above embodiment, the server 30 (control device 31) determines that the unexpected departure has occurred based on the charging power of the vehicle 50A acquired by the communication device 33, but the present disclosure is not limited to this. For example, the communication device 33 may be notified by the vehicle 50A (or the EVSE 40) or the like that the unexpected departure has occurred.

[0092] The configurations described in the above embodiment and the various modifications described above may be implemented in any combination.

[0093] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0094] 1 VGI system (power system), 30 server (power control device), 50A vehicle (first power equipment), 50B, 50C vehicle (second power equipment), 50D, 50E vehicle (third power equipment), A period (first period), B period (second period), PG power system, t1 time (predetermined time), Δτ time (predetermined time).

Claims

1. a first power device configured to perform power control including at least one of power supply to a power grid and charging from the power grid during a first period; at least one second power device configured to perform the power control during a second time period subsequent to the first time period; at least one third electric power device configured to perform the power control when at least one of the first electric power device and the second electric power device leaves the power control during the power control; and a power control device that controls the power control of each of the first power device, the second power device, and the third power device, the first period includes a predetermined time that is a predetermined time before a scheduled end time of the first period, The power control device When switching the target of the power control from the first power device to the second power device, a gradual change switching control is performed to switch the target of the power control by gradually changing both the charging amount or the power supply amount in the power control of each of the first power device and the second power device; and when switching a target of the power control from at least one of the first power device and the second power device to a third power device, performing instantaneous switching control to switch the target of the power control by instantaneously changing the amount of charge or power supply in the power control of the third power device to an amount corresponding to the amount of charge or power supply in the power control of the at least one of the first power device and the second power device; determining to perform the gradual switching control when the power control by the first power device has been performed until the predetermined time; The power system determines to perform the immediate switching control when the first power device leaves the power control before the predetermined time.

2. The power control device communicating with each of the first electric power device, the second electric power device, and the third electric power device, and acquiring information regarding a communication delay time between each of the first electric power device, the second electric power device, and the third electric power device; performing the gradual switching control based on the communication delay time of the first electric power device and the communication delay time of the second electric power device; The power system according to claim 1 , wherein the immediate switching control is performed based on the communication delay time of the third power device.

3. a plurality of the second electric power devices and a plurality of the third electric power devices are provided; The power control device selecting, from among the plurality of second electric power devices, a second electric power device having a smallest difference between the communication delay time of the second electric power device and the communication delay time of the first electric power device as a target of the gradual change switching control; The power system according to claim 2 , wherein the third power device having the shortest communication delay time is selected as a target of the immediate switching control from among the plurality of third power devices.

4. the power control device communicates with each of the first power device, the second power device, and the third power device, and acquires information regarding a communication delay time between the first power device, the second power device, and the third power device; The power system according to any one of claims 1 to 3, wherein the predetermined time has a length equal to or greater than the longer of the communication delay time of the first power device and the communication delay time of the second power device.

5. 4. The power system according to claim 1, wherein at least the first electric power device of the first, second, and third electric power devices includes an electric vehicle.

6. The power system according to claim 1 , wherein at least the second electric power device of the second electric power device and the third electric power device includes an electric vehicle.

7. A power control device that controls power control of a first power device capable of power control including at least one of feeding power to an electric power grid or charging from the electric power grid, a second power device capable of the power control, and a third power device capable of the power control, the first power device is set to perform the power control during a first period; the second power device is set to perform the power control during a second period that follows the first period; the third power device is configured to perform the power control when at least one of the first power device and the second power device leaves the power control during the power control, the first period includes a predetermined time that is a predetermined time before a scheduled end time of the first period, When switching the target of the power control from the first power device to the second power device, a gradual change switching control is performed to switch the target of the power control by gradually changing both the charging amount or the power supply amount in the power control of each of the first power device and the second power device; and when switching a target of the power control from at least one of the first power device and the second power device to a third power device, performing instantaneous switching control to switch the target of the power control by instantaneously changing the amount of charge or power supply in the power control of the third power device to an amount corresponding to the amount of charge or power supply in the power control of the at least one of the first power device and the second power device; determining to perform the gradual switching control when the power control by the first power device has been performed until the predetermined time; The power control device determines to perform the immediate switching control when the first power device leaves the power control before the predetermined time.

8. A power control method for controlling power control of a first power device capable of power control including at least one of feeding power to an electric power grid or charging from the electric power grid, a second power device capable of the power control, and a third power device capable of the power control, comprising: the first power device is set to perform the power control during a first period; the second power device is set to perform the power control during a second period that follows the first period; the third power device is configured to perform the power control when at least one of the first power device and the second power device leaves the power control during the power control, the first period includes a predetermined time that is a predetermined time before a scheduled end time of the first period, a gradual change switching step of performing gradual change switching control to switch targets of the power control by gradually changing both the charging amount or the power supply amount in the power control of each of the first power device and the second power device; an immediate switching step of performing immediate switching control to switch a target of the power control by immediately changing the amount of charge or the amount of power supply in the power control of the third power device to an amount corresponding to the amount of charge or the amount of power supply in the power control of at least one of the first power device and the second power device; determining to perform the gradual change switching control when the power control by the first power device has been performed until the predetermined time; determining to perform the immediate switching control when the first powered device leaves the power control before the predetermined time.

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