Management System

Abstract

To reduce the possibility that unexpected charging by a first management device is performed after the first management device transmits information showing the charge / discharge capacity of a vehicle group to a second management device.SOLUTION: A management system includes: a first management device for managing a vehicle group including multiple electric vehicles; and a second management device for requesting an energy management related to an electric power system PG to the first management device. The first management device is configured including: determining whether or not an electric vehicle needed to be immediately charged exists among the vehicle group; acquiring information showing the charge / discharge capacity including at least one of an electric power amount the vehicle group can charge and an electric power amount the vehicle group can discharge, on the premise that the electric vehicle can be immediately charged when it is determined that the electric vehicle needed to be immediately charged exists among the vehicle group; and transmitting the information showing the acquired charge / discharge capacity to the second management device.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a management system for energy management.

Background Art

[0002] Japanese Patent Application Laid-Open No. 2012-060834 (Patent Document 1) discloses a technique for charging a plurality of electric vehicles (for example, electric cars), in which the electric power discharged from an electric vehicle for which the end of charging is expected first is used for charging other electric vehicles.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A management system including a first management device that manages a group of vehicles including a plurality of electric vehicles and a second management device that requests the first management device to perform energy management related to the power system is known. In such a management system, for example, the first management device calculates the charge / discharge available amount of the vehicle group in a future predetermined period and transmits it to the second management device, and the second management device determines the energy management requested to the first management device in the above predetermined period based on the charge / discharge available amount of the vehicle group received from the first management device. However, if charging that was not predicted by the first management device is performed in the above predetermined period according to the user's request, there may be a deviation between the charge / discharge available amount of the vehicle group transmitted by the first management device and the actual charge / discharge available amount of the vehicle group.

[0005] The above discrepancy may hinder the performance of energy management required based on the charge / discharge capacity of the vehicle group transmitted by the first management device. For example, if the actual charge / discharge capacity of the vehicle group is smaller than the value transmitted by the first management device, it becomes difficult to perform the required energy management. Therefore, it is conceivable to offset the above discrepancy by exchanging power between electric vehicles included in the vehicle group (see, for example, Patent Document 1). However, such power exchange between electric vehicles results in losses associated with charging and discharging. To minimize losses, it is desirable to eliminate the need for power exchange between electric vehicles, that is, to reduce the possibility of charging occurring after the first management device has transmitted the charge / discharge capacity of the vehicle group, which the first management device did not anticipate.

[0006] This disclosure was made to solve the above-mentioned problems, and its purpose is to reduce the possibility that charging will occur in a manner not predicted by the first management device after the first management device has transmitted information indicating the charge / discharge capacity of the vehicle group to the second management device. [Means for solving the problem]

[0007] A management system according to one embodiment of this disclosure includes a first management device for managing a group of vehicles including multiple electric vehicles, and a second management device that requests the first management device to perform energy management related to the power grid. Each of the multiple electric vehicles included in the group of vehicles is equipped with a power storage device and is configured to be rechargeable by power from the power grid. The first management device determines whether there is an electric vehicle in the group that requires immediate charging, and if it is determined that there is an electric vehicle in the group that requires immediate charging, it acquires information indicating the charge / discharge amount, which includes at least one of the amount of energy the group can charge and the amount of energy the group can discharge, on the premise that the electric vehicle will perform immediate charging, and is configured to transmit the acquired information indicating the charge / discharge amount to the second management device. Immediate charging is charging that is immediately started by any electric vehicle in the group using power from the power grid when that electric vehicle is electrically connected to the power grid. [Effects of the Invention]

[0008] According to this disclosure, it becomes possible to reduce the possibility of charging occurring in a way that the first management device did not anticipate after the first management device transmits information indicating the charge / discharge capacity of the vehicle group to the second management device. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows a management system according to an embodiment of the present disclosure. [Figure 2] This diagram illustrates the processing flow in the management system shown in Figure 1, in which the first management device acquires and transmits information indicating the charge / discharge capacity. [Figure 3] This is a diagram illustrating an example of information indicating the charge / discharge capacity. [Figure 4] This is a diagram illustrating the energy management performed by the management system according to the embodiment of this disclosure. [Figure 5] This figure illustrates an example of charge / discharge control according to this embodiment. [Figure 6] This diagram illustrates the power transfer between electric vehicles included in a group of vehicles. [Modes for carrying out the invention]

[0010] Embodiments of this disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated.

[0011] Figure 1 is a diagram illustrating an overview of a power system and management system according to an embodiment of the present disclosure. Referring to Figure 1, the power system includes a power grid PG, a plurality of EVSEs (Electric Vehicle Supply Equipment) 10, and a plurality of energy storage devices 20. The power grid PG is a power grid constructed by transmission and distribution equipment. The power grid PG may also include substations. The power grid PG may be connected to power generation equipment not shown. Each of the plurality of EVSEs 10 and the plurality of energy storage devices 20 is electrically connected to the power grid PG. In this embodiment, the EVSEs 10 are AC power supply equipment that outputs alternating current power. However, the invention is not limited to this, and the EVSEs 10 may also be DC power supply equipment that outputs direct current power. The EVSEs 10 may be chargers installed (fixed) in a house or public charging stations. The energy storage devices 20 are stationary energy storage devices. The energy storage devices 20 may be commercial ESSs (Energy Storage Systems) or energy storage devices installed (fixed) in a house.

[0012] The management system includes a power market system 100, an EMS (Energy Management System) 200, and a VPP (Virtual Power Plant) system 300.

[0013] The VPP system 300 manages a group of vehicles VG including multiple electric vehicles 30. Each of the multiple electric vehicles 30 included in the group of vehicles VG is equipped with a power storage device 31, and is configured to be rechargeable with power from the power grid PG. The power storage device 31 corresponds to an on-board battery. The electric vehicles 30 are configured to be able to run using the power output from the power storage device 31. The electric vehicles 30 are further equipped with a drive system (e.g., one or more motors, not shown) that rotates the drive wheels of the electric vehicles 30 using the power from the power storage device 31. The electric vehicles 30 may be electric vehicles without an internal combustion engine (BEV) or plug-in hybrid electric vehicles (PHEV) equipped with an internal combustion engine. Figure 1 shows an example of the configuration of an electric vehicle 30.

[0014] In addition to the energy storage device 31, the electric vehicle 30 further includes a charge / discharge circuit 32 (on-board charger / discharger), an inlet 33 (power receiving port), an ECU (Electronic Control Unit) 35, an HMI (Human Machine Interface) 38, and a communication device 39. The ECU 35 includes a processor 351 and a memory device 352. The energy storage device 31 is equipped with a BMS (Battery Management System) 31a that monitors the state of the energy storage device 31. The BMS 31a includes various sensors that detect the state of the energy storage device 31 and outputs the detection results to the ECU 35. For example, the BMS 31a detects the temperature, current, voltage, and SOC (State of Charge) of the energy storage device 31. SOC indicates the amount of stored energy, for example, the ratio of the current amount of stored energy to the amount of stored energy when fully charged, expressed as 0 to 100%.

[0015] When the tip (connector 12) of the charging cable 11 connected to the EVSE 10 is connected to the inlet 33 of the parked electric vehicle 30 (plugging it in), the electric vehicle 30 is electrically connected to the EVSE 10 (and by extension, to the power grid PG). Hereinafter, the state in which the electric vehicle 30 and the power grid PG are electrically connected will be referred to as the "grid-connected state," and the state in which the electric vehicle 30 and the power grid PG are not electrically connected will be referred to as the "grid-disconnected state."

[0016] The charge / discharge circuit 32 includes a power conversion circuit (e.g., a bidirectional inverter). In a grid-connected electric vehicle 30, external charging (charging of the energy storage device 31 with power from outside the vehicle) and external power supply (power supply to the outside of the vehicle using power from the energy storage device 31) become possible. The electric vehicle 30 can perform energy management of the power grid PG through external charging and external power supply. Power for external charging is supplied to the inlet 33 from the power grid PG, for example, through the EVSE 10. The charge / discharge circuit 32 converts the power received by the inlet 33 into power suitable for charging the energy storage device 31 (e.g., DC power) and outputs the converted power to the energy storage device 31. Power for external power supply is supplied from the energy storage device 31 to the charge / discharge circuit 32. The charge / discharge circuit 32 converts the DC power supplied from the energy storage device 31 into power suitable for external power supply (e.g., AC power) and outputs the converted power to the inlet 33. In the following explanation, the charging, discharging, and storage amounts of the electric vehicle 30 refer to the charging, discharging, and storage amounts of the energy storage device 31, respectively.

[0017] The HMI38 includes an input device and a display device. The HMI38 includes, for example, a navigation system (hereinafter referred to as "navigator"). The navigation system detects the position of the electric vehicle 30 using a positioning system such as GPS (Global Positioning System). When the user sets a destination in the navigation system, the navigation system displays the driving route to the destination to the user. The ECU35 communicates wirelessly with the VPP system 300 via a communication device 39. The VPP system 300 can remotely perform charge and discharge control of the electric vehicle 30 when it is connected to the grid.

[0018] The mobile terminal 50 is carried by the user of the electric vehicle 30. The mobile terminal 50 is, for example, a smartphone equipped with a touch panel display. Application software for using the VPP system 300 is installed in the mobile terminal 50. The mobile terminal 50 receives a charging reservation from the user. The user can reserve (request) charging to make the SOC of the power storage device 31 not less than the target SOC by the scheduled departure time by inputting the scheduled departure time and the target SOC at that time into the mobile terminal 50 to the VPP system 300. The mobile terminal 50 transmits information regarding the reserved charging (hereinafter referred to as "charging reservation information") to the VPP system 300 together with the identification information of the corresponding electric vehicle 30. The charging reservation information includes the scheduled departure time and the target SOC input by the user.

[0019] The EMS200 may be a CEMS (City EMS) or a FEMS (Factory EMS). The EMS200 comprises a processor 201 and a storage device 202. The EMS200 is configured to directly or indirectly control each of the multiple energy storage devices 20. The VPP system 300 comprises a processor 301 and a storage device 302. The storage device 302 stores information about each electric vehicle included in the vehicle group VG, distinguishing it by identification information (vehicle ID) for each individual vehicle (electric vehicle 30). The storage device 302 pre-stores specification information (e.g., storage capacity) of the energy storage device 31 for each electric vehicle included in the vehicle group VG. In addition, each of the multiple electric vehicles 30 included in the vehicle group VG sequentially transmits the status of the vehicle system (operating / stopped), navigation information, and the position and status of its own vehicle (electric vehicle 30) detected by on-board sensors to the VPP system 300. The processor 301 updates the information in the storage device 302 using information (location, SOC, charging reservation information, etc.) acquired from the electric vehicle 30 or mobile terminal 50. In this embodiment, the controls shown in Figures 2 and 4, described later, are executed by one or more processors executing programs stored in one or more storage devices. However, these processes may be executed by hardware (electronic circuits) alone, not by software. The VPP system 300 and EMS 200 correspond to examples of the "first management device" and "second management device" according to this disclosure, respectively.

[0020] The EMS200 is configured to communicate with both the power market system 100 and the VPP system 300. The EMS200 transmits a signal (hereinafter referred to as the "first request signal") to the VPP system 300 requesting the amount of charge / dischargeable capacity of the vehicle group VG during a predetermined future period (hereinafter referred to as the "target period"). The EMS200 may transmit the first request signal based on a power supply and demand forecast. Upon receiving the first request signal, the VPP system 300 obtains information (hereinafter referred to as "VPP information") indicating the amount of charge / dischargeable capacity of the vehicle group VG during the target period. The charge / dischargeable capacity includes at least one of the amount of energy that the vehicle group VG can charge and the amount of energy that the vehicle group VG can discharge. The VPP system 300 transmits the VPP information to the EMS200.

[0021] FIG. 2 is a diagram for explaining a processing flow in which the VPP system 300 acquires and transmits VPP information. When the VPP system 300 receives the above-described first request signal, it starts a processing flow F1 shown as a flowchart in FIG. 2. "S" in the flowchart means a step. In S11, the processor 301 makes a movement prediction (behavior prediction) for each electric vehicle included in the vehicle group VG using the information of each electric vehicle (for example, position, SOC, charging reservation information) stored in the storage device 302. The processor 301 may make a movement prediction of the electric vehicle 30 using a travel plan (for example, departure place, departure time, destination, arrival time, travel route to the destination, etc.) set in the navigation of the electric vehicle 30. The processor 301 may predict the movement schedule of the electric vehicle 30 from historical data (for example, weather information, traffic jam information, and past position data managed separately according to the day of the week) regarding the movement (user behavior) of the electric vehicle 30. While tracking the position of the electric vehicle 30 using the position information of the electric vehicle 30, the processor 301 may predict the arrival time of the electric vehicle 30 at the destination and the remaining battery level (SOC) at the time of arrival. The processor 301 may predict the scheduled departure time of the electric vehicle 30 using the charging reservation information.

[0022] In this embodiment, the processor 301 predicts, in S11, the change in the amount of charge stored along with the change in the position of the electric vehicle 30. The processor 301 also predicts, for each electric vehicle included in the vehicle group VG, the connection timing, which is the timing when the electric vehicle changes from a disconnected state to a connected state with respect to the power grid PG; the amount of charge stored in the electric vehicle at the connection timing; and the disconnection timing (for example, the scheduled departure time), which is the timing when the electric vehicle becomes disconnected from the power grid PG after the connection timing. Based on these predictions, the processor 301 estimates what state each electric vehicle included in the vehicle group VG will be in during the aforementioned target period. Specifically, the processor 301 classifies each electric vehicle included in the vehicle group VG into electric vehicle 30A (hereinafter also referred to as "standby vehicle"), which is always connected to the grid during the target period; electric vehicle 30B (hereinafter also referred to as "operating vehicle"), which is always disconnected from the grid during the target period; electric vehicle 30C (hereinafter also referred to as "connected vehicle"), which changes from disconnected to connected during the target period; and electric vehicle 30D (hereinafter also referred to as "disconnected vehicle"), which changes from connected to the grid to disconnected during the target period.

[0023] In the following S12, the processor 301 determines whether or not there is an electric vehicle 30 in the vehicle group VG that requires immediate charging. More specifically, the processor 301 determines whether or not immediate charging is required for each electric vehicle classified as a connected vehicle in S11. Immediate charging is external charging that is started immediately by the electric vehicle using power from the power system PG when the electric vehicle is electrically connected to the power system PG (when the electric vehicle 30 changes from a disconnected state to a connected state). The processor 301 may determine whether or not immediate charging is required for the electric vehicle using the predicted connection timing and disconnection timing. For example, the processor 301 may determine that immediate charging is required for electric vehicles whose time from connection timing to disconnection timing (hereinafter referred to as "departure buffer time") is shorter than a predetermined value. Furthermore, the processor 301 may increase the predetermined value as the amount of charge stored at the predicted connection timing for the electric vehicle decreases. There is a tendency for the need for immediate charging to increase as the departure buffer time decreases. Also, there is a tendency for the need for immediate charging to increase as the amount of charge stored at connection timing decreases. The processor 301 may determine, for example, that electric vehicles that arrive (plug in) at night in a low SOC state and depart a few hours later require immediate charging, while electric vehicles that arrive (plug in) at night in a low SOC state and remain connected to the grid until morning do not require immediate charging.

[0024] If it is determined that immediate charging is required for at least one electric vehicle 30 classified as a connected vehicle, the response in S12 is YES, and the process proceeds to S13. Hereafter, connected vehicles that are determined to require immediate charging will be referred to as "immediate charging vehicles." Connected vehicles that are determined not to require immediate charging, disconnected vehicles, and standby vehicles will each be referred to as "VPP vehicles."

[0025] In S13, the processor 301 creates a charging plan for the instant charging vehicle during the target period. The charging plan shows the progression of the charging power of the energy storage device 31. For the instant charging vehicle, the processor 301 may calculate the start and end times of instant charging using, for example, the amount of stored energy at the connection timing (predicted value in S11) and the target SOC (charging reservation information) for the scheduled departure time. Instead of the target SOC set by the user, a predetermined fixed value (for example, an SOC value near full charge) may be used. The charging plan for the instant charging vehicle includes the amount of energy required for instant charging and the time period during which instant charging is performed. The VPP system 300 may acquire specification information (for example, rated charging power) of the EVSE 10 to which the instant charging vehicle is connected at the connection timing, and determine the time required for instant charging based on that specification information. If there are multiple instant charging vehicles in the vehicle group VG, the processor 301 creates a charging plan for each instant charging vehicle. Once the creation of charging plans for all instant charging vehicles is complete, the process proceeds to S14.

[0026] In S14, the processor 301 uses the results of the behavior prediction in S11 and the charging plan for the instant-charging vehicles created in S13 to obtain VPP information indicating the charge / discharge capacity of the vehicle group VG during the target period. The processor 301 obtains VPP information indicating the charge / discharge capacity of the vehicle group VG assuming that the instant-charging vehicles perform instant charging. The VPP information includes the charging plan for the instant-charging vehicles. The processor 301 calculates the charge / discharge capacity of the vehicle group VG based on the vehicle group capacity and the vehicle group's stored energy. The vehicle group capacity is the maximum total energy that can be stored by all electric vehicles in the vehicle group VG that are electrically connected to the power grid PG. The vehicle group's stored energy is the total energy stored by all electric vehicles in the vehicle group VG that are electrically connected to the power grid PG. In S14, information showing the trends of the vehicle group capacity and the vehicle group's stored energy during the target period is obtained as VPP information. For instant-charging vehicles, the processor 301 calculates the vehicle group's stored energy by taking into account the change in the stored energy of the instant-charging vehicle due to instant charging.

[0027] Figure 3 is a diagram illustrating an example of VPP information. It shows an example in which the first to third electric vehicles of a vehicle group VG are electrically connected to the power grid PG for at least a portion of the target period. The first, second, and third electric vehicles correspond to an immediately charging vehicle, a standby vehicle, and a connected vehicle that is judged not to require immediate charging, respectively. Times t1 and t2 indicate the connection timing of the third and first electric vehicles, respectively. Lines L11, L21, and L31 show the changes in the energy storage capacity (maximum amount of energy that can be stored) of the first, second, and third electric vehicles, respectively, and line L1 shows the change in the total energy storage capacity (vehicle group capacity) of these electric vehicles. Lines L12, L22, and L32 show the changes in the amount of energy stored (amount of energy held by the energy storage device 31) when the first, second, and third electric vehicles are electrically connected to the power grid PG, respectively, and line L2 shows the change in the total amount of energy stored by these electric vehicles (vehicle group energy storage).

[0028] Referring to Figure 3, line L12 shows the charging plan for the first electric vehicle created in S13 of Figure 2. Time t3 corresponds to the end timing of the immediate charging calculated in S13. The charging plan for the first electric vehicle is created so that immediate charging is performed, starting at time t2 and ending at time t3. Time t4, which is later than time t3, corresponds to the departure timing of the first electric vehicle predicted in S11. Lines L22 and L32 show the changes in the amount of stored energy when the second and third electric vehicles do not charge or discharge during the target period, respectively. This individual vehicle (second electric vehicle, third electric vehicle) prediction information is created based on the results of the behavior prediction in S11 of Figure 2.

[0029] Lines L1 and L2 show the changes in the charge / discharge capacity of the vehicle group VG during the target period. The value obtained by subtracting the vehicle group's stored energy amount shown by line L2 from the vehicle group capacity (charge limit) shown by line L1 corresponds to the amount of electricity that the vehicle group VG can charge (chargeable amount). The value obtained by subtracting the discharge limit (e.g., 0 kWh) from the vehicle group's stored energy amount shown by line L2 corresponds to the amount of electricity that the vehicle group VG can discharge (dischargeable amount). Note that Figure 3 shows an example with two VPP vehicles, but the number of VPP vehicles is arbitrary. The number of VPP vehicles can be 3 or more but less than 50, or 50 or more.

[0030] Referring again to Figure 2, if it is determined that immediate charging is not required for all electric vehicles 30 classified as connected vehicles, then the result in S12 is NO, and the process skips S13 and proceeds to S14. In this case as well, in S14, the processor 301 uses the results of the behavior prediction in S11 to obtain the aforementioned VPP information. However, since there are no electric vehicles in the vehicle group VG that require immediate charging, immediate charging is not considered in the calculation of the vehicle group's energy storage capacity.

[0031] When VPP information is acquired in S14, the VPP system 300 transmits that VPP information to the EMS200 in S15. At this time, the VPP system 300 may also transmit information showing the trend of the maximum power (maximum charging power and / or maximum discharging power) that the vehicle group VG can charge and discharge during the target period, in addition to the VPP information. For each VPP vehicle, the VPP system 300 may acquire specification information of the EVSE10 to which the electric vehicle is connected (for example, rated power indicating charge and discharge capacity) and determine the maximum power (kW) that the electric vehicle can charge and discharge based on that specification information. Once the process in S15 is executed, the processing flow F1 ends.

[0032] Figure 4 is a diagram illustrating the energy management according to this embodiment. When the EMS200 receives the above VPP information, it starts the processing flow F2.

[0033] Referring to Figure 4, in S21, EMS200 conducts power trading based on the charge / discharge capacity of the vehicle group VG (distributed power source). Specifically, EMS200 uses the charge / discharge capacity of the vehicle group VG for the target period indicated by the VPP information to determine the bid amount for the target period and transmits the bid information, including the bid amount, to the power market system 100. Subsequently, if the commodity bid on by EMS200 is successfully bid on in the power market, a contract is concluded. In this case, the target period becomes the contract period, and the bid amount becomes the contract amount. The power market may be a spot market, a pre-hour market, or a supply and demand adjustment market, and may be established and operated by a wholesale power exchange such as JEPX (Japan Electric Power Exchange). In each market, trading takes place with electricity as the commodity.

[0034] In the subsequent S22, EMS200 requests energy management for the power grid PG from VPP system 300 based on the results of the above power transaction. Specifically, EMS200 creates a charge / discharge plan for vehicle group VG in order to have vehicle group VG perform energy management (charge / discharge) corresponding to at least a portion of the contracted amount during the contracted period (target period). EMS200 creates a charge / discharge plan for vehicle group VG so that the amount of charge / discharge of vehicle group VG during the target period does not exceed the charge / discharge capacity. The charge / discharge plan shows at least one of the changes in the charging power of vehicle group VG and the changes in the discharging power of vehicle group VG during the target period. Then, EMS200 transmits a signal (hereinafter referred to as the "second request signal") containing the created charge / discharge plan for vehicle group VG to VPP system 300. The second request signal requests VPP system 300 to charge / discharge vehicle group VG according to the above charge / discharge plan. This completes processing flow F2.

[0035] When the VPP system 300 receives the second request signal, it starts processing flow F3. In S31, the VPP system 300 creates a charge / discharge plan for each VPP vehicle (individual vehicle) by distributing the amount of charge / discharge required to execute the charge / discharge plan for the vehicle group VG indicated by the second request signal to multiple VPP vehicles (individual vehicles). The charge / discharge plan may be either a charging plan or a discharging plan. The VPP system 300 creates a charge / discharge plan for each VPP vehicle so that charging by one VPP vehicle and discharging by another VPP vehicle do not occur simultaneously. This suppresses the exchange of power between electric vehicles (see Figure 6), which will be described later. If the second request signal indicates a charge plan for the vehicle group VG, the VPP system 300 may determine the charge plan for each VPP vehicle such that the earlier the scheduled departure time indicated by the charge reservation information, the earlier the charging start time. This makes it easier for the user to perform the charging they desire.

[0036] In the subsequent S32, the VPP system 300 sends charge / discharge instructions (remote instructions) to each corresponding electric vehicle (instant charging vehicle, VPP vehicle) so that the charge plan for the instant charging vehicle created in S13 in Figure 2 and the charge / discharge plan for each VPP vehicle (individual vehicle) created in S31 are executed. However, if there are no instant charging vehicles in the vehicle group VG, the charge plan for the instant charging vehicle is not created in S13 in Figure 2, and in S32, charge / discharge instructions are sent only to the VPP vehicles. The VPP system 300 then performs charge / discharge control (remote control) for each individual vehicle based on the above charge / discharge instructions (charge instructions and / or discharge instructions). Once the charge / discharge control (S32) is completed, the processing flow F3 ends.

[0037] The ECU 35 of each electric vehicle included in the vehicle group VG starts processing flow F4 when the corresponding electric vehicle 30 changes from a grid disconnected state to a grid connected state. In S41, the ECU 35 determines whether the corresponding electric vehicle 30 (target vehicle) has received a charge / discharge instruction (S32) from the VPP system 300. If the target vehicle has received a charge / discharge instruction (YES in S41), the ECU 35 executes charge / discharge control of the energy storage device 31 in S42 according to the charge / discharge instruction from the VPP system 300. The ECU 35 controls the charge / discharge circuit 32 according to the charge / discharge instruction. If the target vehicle is a VPP vehicle, the charge / discharge plan assigned to that VPP vehicle is executed by the target vehicle. As a result, the charge / discharge plan for vehicle group VG requested by the EMS 200 from the VPP system 300 is executed by multiple VPP vehicles. If the target vehicle is an immediate charging vehicle, immediate charging is performed by the target vehicle. Once the charge / discharge control (S42) is completed, processing flow F4 ends.

[0038] Figure 5 is a diagram illustrating an example of the charge / discharge control (remote control) described above. In Figure 5, the same reference numerals are used for parameters that are the same as those shown in Figure 3. Referring to Figure 5, in this example, a charge plan indicated by line L2A is created as the charge / discharge plan for the vehicle group VG and transmitted from EMS200 to VPP system 300 (S22 in Figure 4). Using the VPP information received from VPP system 300, EMS200 creates a charge plan (line L2A) that shows the change in charging power of vehicle group VG during the target period, so that the amount of stored energy in the vehicle group does not exceed the vehicle group capacity. VPP system 300 controls vehicle group VG using the charge plan received from EMS200. Specifically, the charge plan indicated by line L2A requests VPP system 300 to charge from time t4 to time t6. VPP system 300 creates charge plans for the second and third electric vehicles respectively so that the charging requested from this charge plan is executed. The VPP system 300 creates, for example, a first vehicle charging plan that causes the second electric vehicle to be charged during the period from time t4 to time t5, as indicated by line L22A, and a second vehicle charging plan that causes the third electric vehicle to be charged during the period from time t5 to time t6, as indicated by line L32A. Then, through the processes of S32 and S42 in Figure 4, charge / discharge control (remote control) is performed for each vehicle according to the immediate charging plan that causes the first electric vehicle to be charged during the period from time t2 to time t3, as indicated by line L12, the first vehicle charging plan indicated by line L22A, and the second vehicle charging plan indicated by line L32A.

[0039] Referring again to Figure 4, if the target vehicle does not receive a charge / discharge instruction (NO in S41), the ECU 35 determines in S43 whether or not it has received a charge request from the user. The user may request a charge from the ECU 35, for example, through a mobile terminal 50 or HMI 38. If a charge request is received from the user (YES in S43), in S44, the ECU 35 controls the charge / discharge circuit 32 so that external charging is performed until the State of Charge (SOC) of the energy storage device 31 reaches a predetermined SOC value. The predetermined SOC value may be set by the user or may be a fixed value. The ECU 35 performs charge control (local control) of the energy storage device 31 regardless of external instructions. Once the charge control (S44) is completed, the processing flow F4 ends.

[0040] If both S41 and S43 result in a NO, the process returns to the first step (S41). The decisions in S41 and S43 are repeated until either S41 or S43 results in a YES. However, if the vehicle in question becomes disconnected from the system, the processing flow F4 terminates.

[0041] As described above, even if S41 determines NO when the target vehicle changes from a disconnected state to a connected state, if the user requests charging from ECU35, S43 will determine YES and immediate charging will be performed. Users can perform immediate charging at their own discretion. However, if immediate charging is performed at the user's instruction during the target period, there is a possibility that a discrepancy may occur between the charge / discharge capacity of the vehicle group VG indicated by the VPP information and the actual charge / discharge capacity of the vehicle group VG.

[0042] Therefore, the VPP system 300 according to this embodiment is configured to acquire VPP information (see Figure 3) indicating the charge / discharge capacity of the vehicle group VG, assuming that an electric vehicle requiring immediate charging is to perform immediate charging, if such electric vehicle (immediate charging vehicle) is present in the vehicle group VG, and to transmit the acquired VPP information to the EMS 200 (see Figure 2). This reduces the possibility that charging (especially immediate charging) that was not predicted by the VPP system 300 will be performed after the VPP system 300 transmits the VPP information to the EMS 200. The EMS 200 will be able to formulate a charge / discharge plan for the vehicle group VG that takes into account the power generated by the immediate charging vehicle. The EMS 200 does not handle information on individual vehicles, but only information on the vehicle group VG. This reduces the information processing load (e.g., computational load) on the EMS 200.

[0043] Furthermore, the VPP system 300 remotely controls the immediate charging of vehicles requiring immediate charging (see Figure 4). In other words, for electric vehicles that require immediate charging during the target period, immediate charging is performed remotely. Therefore, the possibility of immediate charging being performed by user instruction during the target period is low. Thus, the occurrence of the above-mentioned discrepancy is suppressed.

[0044] If, during the target period, there is a discrepancy between the charge / discharge capacity of the vehicle group VG indicated by the VPP information and the actual charge / discharge capacity of the vehicle group VG, the VPP system 300 may cancel out the discrepancy by exchanging power between the electric vehicles included in the vehicle group VG. Figure 6 is a diagram illustrating the exchange of power between electric vehicles included in the vehicle group VG.

[0045] Referring to Figure 6, the VPP system 300 may, when both the electric vehicle 30E in a low SOC state and the electric vehicle 30F in a high SOC state are connected to the grid, cause the electric vehicle 30F, which has a larger stored energy capacity, to receive a predetermined amount of external power (discharge to the power grid PG), and also cause the electric vehicle 30E, which has a smaller stored energy capacity, to receive the same predetermined amount of external power. This allows for the exchange of the predetermined amount of power between the electric vehicles 30E and 30F. The exchange of power is carried out via the power grid PG. However, such power exchange between electric vehicles results in losses associated with charging and discharging. To minimize these losses, it is desirable to eliminate the need for the above-mentioned power exchange between electric vehicles, that is, to reduce the possibility of charging occurring after the VPP system 300 transmits VPP information (S15 in Figure 2) that the VPP system 300 did not anticipate.

[0046] The processing flows shown in Figures 2 and 4 can be modified as appropriate. For example, the order of processing may be changed or unnecessary steps may be omitted depending on the purpose. Also, the content of any of the processes may be changed. For example, in S15, the VPP system 300 may separately send information to the EMS 200 showing the trends in storage capacity and stored amount for the immediate charging vehicle, and information showing the trends in storage capacity and stored amount for the VPP vehicle. Also, in S43 of processing flow F4 (Figure 4), the ECU 35 may determine whether the user has requested charging based on the charging reservation information. Also, if there is an immediate charging vehicle in the vehicle group VG, the VPP system 300 may send a charge / discharge instruction only to the VPP vehicle in S32 of processing flow F3 (Figure 4). For immediate charging vehicles, it is predicted that immediate charging will be necessary, and even if the VPP system 300 does not instruct the immediate charging vehicle to charge, there is a high possibility that immediate charging (local control) will be performed upon request from the user.

[0047] The power grid (PG) is not limited to large-scale AC grids; it may also be a microgrid or a DC (direct current) grid. The mobile terminal 50 is not limited to smartphones; it may also be other terminals (wearable devices, portable game consoles, etc.).

[0048] The configuration of the electric vehicle is not limited to the configuration described above (see Figure 1). In the above embodiment, each electric vehicle included in the vehicle group VG is configured to discharge power from the energy storage device 31 to the power grid PG. However, this configuration is not mandatory, and the electric vehicle may be equipped with a charger (charging circuit) instead of a charger / discharger. The power conversion circuit for charging and discharging the on-board battery may be mounted on the EVSE instead of the electric vehicle. The electric vehicle may be configured to enable contactless charging. An electric vehicle that performs contactless charging may be considered to have entered a state equivalent to the "grid connection state" described above when the alignment of the power transmission unit (e.g., power transmission coil) on the power supply equipment side and the power receiving unit (e.g., power receiving coil) on the electric vehicle side is completed. The electric vehicle may be configured to enable autonomous driving. The electric vehicle is not limited to a four-wheeled passenger car, but may be a bus or a truck, and the number of wheels is arbitrary.

[0049] The above variations may be combined in any way as desired.

[0050] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the description of the embodiments above, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of symbols]

[0051] 30 electric vehicles, 31 energy storage devices, 200 energy management systems, 300 virtual power plant systems, and power grids.

Claims

1. A management system comprising a first management device for managing a group of vehicles including multiple electric vehicles, and a second management device for requesting energy management related to the power grid from the first management device, Each of the multiple electric vehicles included in the aforementioned group of vehicles is equipped with a power storage device and is configured to be rechargeable by power from the power grid. The first management device is configured to determine whether or not there is an electric vehicle in the vehicle group that requires immediate charging, and if it is determined that there is an electric vehicle in the vehicle group that requires immediate charging, it acquires information indicating the charge / discharge amount, which includes at least one of the amount of power that the vehicle group can charge and the amount of power that the vehicle group can discharge, on the premise that the electric vehicle will be immediately charged, and transmits the acquired information indicating the charge / discharge amount to the second management device. The aforementioned instant charging is a management system in which, when any of the electric vehicles included in the group of vehicles is electrically connected to the power system, the electric vehicle immediately starts charging using power from the power system.

2. The first management device is configured to predict, for each of the plurality of electric vehicles included in the vehicle group, the connection timing which is the timing at which the electric vehicle changes from a disconnected state to a connected state with respect to the power system, and the disconnection timing which is the timing at which the electric vehicle becomes disconnected from the power system after the connection timing. The management system according to claim 1, wherein the first management device is configured to determine whether or not there is an electric vehicle in the group of vehicles that requires immediate charging, using the predicted connection timing and disconnection timing.

3. The management system according to claim 2, wherein the first management device is configured to further predict the amount of charge stored in each of the plurality of electric vehicles included in the vehicle group at the connection timing, and to determine whether or not there is an electric vehicle in the vehicle group that requires immediate charging, using the predicted amount of charge stored.

4. The first management device is configured to acquire information indicating the charge / discharge capacity, which represents the changes in the vehicle group capacity, which is the maximum total amount of energy that can be stored by all electric vehicles in the vehicle group that are electrically connected to the power system, and the vehicle group energy storage amount, which is the total amount of energy that has been stored by all electric vehicles in the vehicle group that are electrically connected to the power system, over a predetermined period. The management system according to any one of claims 1 to 3, wherein the first management device is configured to calculate the total amount of stored power for the group of vehicles by taking into account the change in the amount of stored power of electric vehicles due to immediate charging for electric vehicles that require immediate charging during the predetermined period.

5. The second management device is configured to use the information indicating the chargeable / dischargeable amount received from the first management device to create a charging plan showing the change in the charging power of the vehicle group over a predetermined period so that the vehicle group's stored energy does not exceed the vehicle group's capacity, and to transmit the created charging plan to the first management device. The management system according to claim 4, wherein the first management device is configured to control the group of vehicles using the charging plan received from the second management device.

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