Power Management System

Abstract

To suppress an increase in the number of times of switching of a relay that switches the connection state between a power grid and an on-vehicle power storage device.SOLUTION: A server executes, when there is an increase DR request (YES in S100), processing including: a step (S102) of acquiring various information; a step (S104) of identifying a vehicle whose charging relay is to be turned on; a step (S108) of selecting a vehicle whose charging relay is to be kept in an on state if there is a vehicle whose number of times the charging relay is turned on exceeds an upper limit value (YES in S106); a step (S112) of setting shortening of the minimum duration time if there is a vehicle whose most recent charging exceeded a threshold (S110), a step (S114) of selecting a vehicle whose charging relay can be turned off using the number of on times; a step (S116) of setting a DR request amount; and a step (S118) of updating and transmitting relay control information.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a power management system including a vehicle equipped with a power storage device. [Background technology]

[0002] Conventionally, VPPs (Virtual Power Plants) have been known that function as if they were a single power plant by remotely and integrally controlling small-scale energy resources such as power storage devices mounted on electric vehicles parked at factories or homes using a server or the like. In a VPP, for example, it is possible to level out the power demand by changing the power demand in the power grid by charging and discharging the on-board power storage device connected to the power grid. For example, when a request is received to increase the power demand in the power grid (i.e., an up-DR (Demand Response)), the power demand can be increased by charging the on-board power storage device connected to the power grid.

[0003] Such electric vehicles are provided with a switching device such as a relay for switching between a state in which electric power can be exchanged with the power grid and a state in which electrical connection with the power grid is cut off. For example, JP 2021-027721 A (Patent Document 1) discloses a technology for prohibiting a switching operation in response to a power transaction when the number of times a relay is switched from one of an open state and a closed state to the other exceeds a threshold value. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-027721 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if switching operations in response to electricity transactions are uniformly prohibited when the number of switching times exceeds a threshold, there are cases where the vehicle cannot participate in a DR request in the VPP after that. As a result, the number of vehicles participating in the DR request decreases, and the vehicle may not be able to respond to the DR request with good responsiveness. In particular, in a vehicle (V1G vehicle) that can only externally charge an on-board power storage device using power from an external power grid, the number of relay switching times may increase more than expected by responding to a DR request, compared to a vehicle (V2G vehicle) that can receive and send power to and from an external power grid. Therefore, in a vehicle that can participate in a DR request, it is necessary to suppress the increase in the number of relay switching times.

[0006] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide a power management system that suppresses an increase in the number of times a relay that switches the connection state between a power grid and an on-board power storage device is switched. [Means for solving the problem]

[0007] A power management system according to an aspect of the present disclosure is a power management system that manages power exchanged between a VPP (Virtual Power Plant) connected to a power grid installed within a predetermined area and outside the power grid. The VPP is configured to be connectable / disconnectable to / from the power grid via a relay, and includes a plurality of vehicles equipped with a power storage device that can be charged by receiving power supply from the power grid. The power management system includes a server that can communicate with the plurality of vehicles. The server acquires a state of the relay for each of the plurality of vehicles. When a target vehicle among the plurality of vehicles receives power supply from the power grid in response to a request for an increase in the demand for power in the power grid and charges the power storage device, if the number of times the relay is turned on to change from a disconnected state to a connected state exceeds a first value, the server instructs the target vehicle to maintain the connected state of the relay until a charging process in accordance with the request is completed.

[0008] In this way, when charging is performed in response to a request to increase the demand, the relay is maintained in a connected state until the charging is completed, so that charging of the power storage device can be completed and an increase in the total number of times the relay is turned on can be suppressed. This makes it possible to suppress deterioration of the relay when the target vehicle is used as part of a VPP.

[0009] In one embodiment, the period during which the charging process is performed includes a period during which charging of the power storage device is interrupted.

[0010] In this way, the relay is maintained in a connected state during the period in which the charging process is performed in accordance with the request, including the period in which the charging of the storage device is interrupted, thereby suppressing an increase in the total number of times the relay is turned on.

[0011] Furthermore, in one embodiment, the vehicle includes a control device that controls the relay such that the duration for which the relay remains in a connected state during the charging process does not fall below a second value.

[0012] In this way, the relay is controlled so that the duration of the relay's connected state does not fall below the second value, making it possible to prevent the relay from being turned on and off at intervals shorter than the second value, thereby making it possible to prevent an increase in the total number of times the relay is turned on.

[0013] In yet another embodiment, the control device sets the second value to be smaller when the previous charging time is greater than the third value than when the previous charging time is less than the third value.

[0014] In this way, an increase in the total number of times the relay is turned on due to a long previous charging time is suppressed, and by making the second value small, the charging process can be stopped with good responsiveness in response to a request.

[0015] Furthermore, in one embodiment, the server sets at least one of the first value and the second value using the charging power in the charging process.

[0016] In this way, by setting a first value or a second value according to the charging power in the charging process, it is possible to suppress an increase in the total number of times the relay is turned on, while responsively stopping the charging process in response to a request.

[0017] In yet another embodiment, the server selects a vehicle having a number of on-times greater than a fourth value from among the plurality of vehicles as a vehicle for adjusting the demand amount using a predetermined adjustment power. The predetermined adjustment power includes a adjustment power having a longer response time than any of a plurality of adjustment powers having different response times for adjusting the demand amount in response to a request.

[0018] In this way, when the demand amount is adjusted using a regulation capability with a long response time, the relay may be turned on less frequently than when the demand amount is adjusted using a regulation capability with a short response time. Therefore, by selecting a vehicle with a number of on-times greater than the fourth value as a vehicle for adjusting the demand amount using a predetermined regulation capability, it is possible to suppress an increase in the total number of on-times of the relay of the vehicle.

[0019] Furthermore, in one embodiment, the server selects, from among a plurality of vehicles, a vehicle capable of turning off the relay during the period in which the charging process is performed, using the number of times the relay is turned on.

[0020] In this way, it is possible to prevent an increase in the total number of times the relay of a particular vehicle is turned on among a plurality of vehicles.

[0021] Furthermore, in one embodiment, the server selects a vehicle whose difference between the charging power during the charging process and the most recent charging power is less than or equal to a threshold value as a vehicle for which the relay will remain connected until the charging process is completed.

[0022] In this way, in a vehicle in which the charging power during the charging process in accordance with a request does not fluctuate significantly compared to the most recent charging power, the relay is maintained in a connected state until the charging process is completed, thereby suppressing an increase in the total number of times the relay is turned on.

[0023] In one embodiment, the plurality of vehicles includes a V1G vehicle that is supplied with power unilaterally from a power grid, and the server selects a V1G vehicle whose charge power in a charging process and whose most recent charge power are equal to or smaller than a threshold value as a vehicle whose relay is to be kept connected until the charging process is completed.

[0024] In this way, in a V1G vehicle in which the charging power during the charging process in accordance with a request does not fluctuate significantly compared to the most recent charging power, the relay is maintained in a connected state until the charging process is completed, thereby suppressing an increase in the total number of times the relay is turned on. Effect of the Invention

[0025] According to the present disclosure, it is possible to provide a power management system that suppresses an increase in the number of times a relay that switches the connection state between a power grid and an on-board power storage device is switched. [Brief description of the drawings]

[0026] [Figure 1] 1 is a diagram showing a schematic configuration of a power management system according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a communication system diagram of the power management system. [Diagram 3] FIG. 2 is a diagram illustrating an example of a detailed configuration of a vehicle. [Figure 4] 2 is a diagram for explaining specific processes executed in a processing device of the server and an ECU of a vehicle. FIG. [Diagram 5] 5 is a flowchart illustrating an example of a process executed by a server of the power management system according to the present embodiment. [Figure 6] 13 is a flowchart illustrating an example of a process executed by a server of a power management system according to a modified example. [Figure 7] 13 is a flowchart showing another example of the process executed by the server of the power management system according to the modified example. [Figure 8] FIG. 13 is a diagram showing an example of a detailed configuration of a vehicle according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] 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 characters and their description will not be repeated.

[0028] FIG. 1 is a diagram showing a schematic configuration of a power management system 1 according to this embodiment. In this embodiment, the power management system 1 functions as a VPP (Virtual Power Plant). A VPP is a mechanism that uses advanced energy management technology that utilizes the Internet of Things (IoT) to bundle a large number of distributed energy resources (hereinafter also referred to as "Distributed Energy Resources (DERs)") and remotely and centrally control these DERs to function as if they were a single power plant. In the power management system 1, the VPP function is realized by energy management that utilizes electric vehicles.

[0029] The power management system 1 is a vehicle grid integration (VGI) system. The power management system 1 includes a vehicle group 5 including a plurality of electric vehicles (hereinafter simply referred to as vehicles) 50 and a plurality of electric vehicle supply equipment (EVSE) 40. The number of vehicles 50 and EVSE 40 included in the power management system 1 is not particularly limited. The plurality of vehicles 50 may include at least one of a privately owned vehicle (POV) and a mobility as a service (MaaS) vehicle. A POV is a vehicle owned by an individual. A MaaS vehicle is a vehicle managed by a MaaS operator. The plurality of EVSE 40 may include at least one of a non-public EVSE (for example, a home EVSE) that can be used only by a specific user and a public EVSE that can be used by an unspecified number of users.

[0030] The power management system 1 includes a power company E1. The power company E1 serves as both a power generation business operator and a power transmission and distribution business operator. The power company E1 constructs a power grid by a power plant 11 and a power transmission and distribution facility 12, and maintains and manages the power grid by a server 10. The power plant 11 includes a power generation device for generating electricity, and is configured to supply the power generated by the power generation device to the power transmission and distribution facility 12. The power generation method of the power plant 11 is arbitrary. The power generation method of the power plant 11 may be any of thermal power generation, hydroelectric power generation, wind power generation, nuclear power generation, and solar power generation. The power transmission and distribution facility 12 includes a transmission line, a substation, and a distribution line, and is configured to transmit and distribute the power supplied from the power plant 11. Each of the smart meters 13 and 14 is configured to measure the amount of power usage at predetermined time intervals (for example, every 30 minutes), store the measured amount of power usage, and transmit it to the server 10. The smart meters 13 and 14 are provided for each consumer (e.g., an individual or a company) that uses electricity. The server 10 acquires the amount of electricity used by each consumer from the smart meters 13, 14 of each consumer. The electric power company E1 may receive an electricity fee from each consumer according to the amount of electricity used. The server 10 is configured to be able to communicate with each server 20 included in the upper aggregator E2. In this embodiment, the electric power company E1 corresponds to the manager of the power grid.

[0031] The power management system 1 further includes a higher-level aggregator E2 and a lower-level aggregator E3. An electric utility that aggregates DERs and provides an energy management service is called an "aggregator." The electric power company E1 can adjust power in the power grid by coordinating with the aggregator, for example.

[0032] The upper aggregator E2 includes multiple servers (e.g., servers 20A, 20B, and 20C). Each server included in the upper aggregator E2 belongs to a different operator. The lower aggregator E3 includes multiple servers (e.g., servers 30A, 30B, and 30C). Each server included in the lower aggregator E3 belongs to a different operator.

[0033] Hereinafter, unless otherwise specified, each server included in the upper aggregator E2 will be referred to as a "server 20," and each server included in the lower aggregator E3 will be referred to as a "server 30." The number of servers 20 and 30 is not particularly limited.

[0034] In this embodiment, one server 10 requests energy management from multiple servers 20, and each server 20 that receives a request from the server 10 requests energy management from multiple servers 30. Furthermore, each server 30 that receives a request from the server 20 requests energy management from multiple DER users. Using this hierarchical structure (tree structure), the electric power company E1 can request energy management from many consumers (e.g., vehicle users). The request is made, for example, by DR (demand response).

[0035] When the server 30 receives a request for energy management from the server 20, the server 30 selects a DER to meet the request from among the DERs registered in the server 30. The DER selected in this manner is hereinafter also referred to as an "EMDER." The EMDER may include an on-board battery or a stationary battery.

[0036] The server 30 performs energy management in the area under its jurisdiction. The area under the jurisdiction of the server 30 is a predetermined region, and may be, for example, a region including a town (e.g., a smart city), a region including a factory, or a region including a university campus. The lower aggregator E3 concludes a contract regarding energy management with a user of a DER existing in the area under the jurisdiction of the server 30. A user who has concluded this contract can receive a predetermined incentive by having a DER perform energy management in accordance with a request from the lower aggregator E3. In addition, a user who has agreed to comply with the request but has not complied with the request is subject to a predetermined penalty under the contract. A DER that is obligated to perform energy management under the contract and its user are registered in the server 30.

[0037] After selecting the EMDER, the server 30 transmits a command to each EMDER. This command causes energy management (for example, adjustment of supply and demand in the power grid) to be performed in accordance with the request from the server 20. The server 30 is, for example, a computer including a communication device 31, a storage device 32, and a processing device 33.

[0038] The communication device 31 is configured to be able to communicate with external devices (eg, the server 20 and the vehicle 50) in a predetermined communication format (eg, wireless or wired).

[0039] The storage device 32 includes memories such as a read only memory (ROM) and a random access memory (RAM). The ROM stores programs executed by the processing device 33. The RAM functions as a working memory for processing by the processing device 33.

[0040] The processing device 33 includes a processor such as a CPU (Central Processing Unit). The processing device 33 executes programs stored in the storage device 32 to perform various processes.

[0041] The processing device 33 receives a request signal R1 from the server 20 of the upper level aggregator E2 via the communication device 31, for example.

[0042] The request signal R1 includes information for requesting the server 30 of the lower aggregator E3 to increase the power demand by increasing the power consumption in the power grid (hereinafter referred to as an up DR), or information for requesting the server 30 of the lower aggregator E3 to increase the power supply to the power grid and decrease the power demand (hereinafter referred to as a down DR). The request signal R1 includes information IEC indicating a target power consumption that needs to be consumed in the power grid while the DR is being implemented.

[0043] For example, when the processing device 33 receives a request signal R1 including information requesting an up-DR via the communication device 31, the processing device 33 transmits a DR signal S1 including information requesting an up-DR to the vehicle 50 as the power resource.

[0044] The vehicle 50 is an electric vehicle equipped with a power storage device and a relay. It is assumed that the user of the vehicle 50 has made a contract in advance with the lower aggregator E3 so as to be able to participate in DR using the vehicle 50. Note that, although a case in which the vehicle group 5 includes two vehicles 50A and 50B is shown as an example in FIG. 1 and FIG. 2, the number of vehicles 50 in the vehicle group 5 is not limited to two.

[0045] The server 30 measures the amount of power adjustment for each EMDER (for example, the amount of charging power and / or the amount of discharging power in a predetermined period) using a predetermined watt-hour meter. The amount of power adjustment may be used to calculate an incentive. The predetermined watt-hour meter may be the smart meter 13 or 14, or may be a watt-hour meter mounted on the vehicle 50A, 50B. The watt-hour meter may be installed at any location. The watt-hour meter may be built into the EVSE 40A, 40B. The watt-hour meter may be attached to a portable charging cable.

[0046] In this embodiment, the server 30 is configured to receive the detection values ​​of each of the smart meters 13 and 14 from the server 10. However, without being limited to this, the server 30 may be configured to directly obtain the detection values ​​of each of the smart meters 13 and 14 (without going through the server 10).

[0047] The smart meter 13 is configured to measure the amount of power exchanged between the EVSE 40A and a power grid established by the power plant 11 and the power transmission and distribution facility 12. A vehicle 50A is connected to the EVSE 40A. The server 30B is configured to be able to communicate with the vehicle 50A.

[0048] The smart meter 14 measures the amount of power exchanged between the power grid and the EVSE 40B. A vehicle 50B is connected to the EVSE 40B. The server 30B is configured to be able to communicate with the vehicle 50B.

[0049] For example, when the server 30B receives a request signal R1 from the server 20, the server 30B transmits a charging start command to the vehicle 50A connected to the EVSE 40A, thereby performing energy management through charging the in-vehicle battery. Furthermore, when the server 30B receives a request signal R1 from the server 20, the server 30B transmits a DR signal S1 including a charging start command to the vehicle 50B connected to the EVSE 40B, thereby performing energy management through charging the in-vehicle battery, or transmits a DR signal S1 including a power supply start command to the vehicle 50B, thereby performing energy management through power supply from the in-vehicle battery to the power grid. The server 30B acquires the SOC (State of Charge) of the in-vehicle battery from the vehicle 50A or the vehicle 50B during the execution of energy management.

[0050] 2 is a communication system diagram of the power management system 1. With reference to FIG. 2, the power management system 1 further includes a data center 70 and a mobile terminal 80.

[0051] The data center 70 is configured to communicate with the server 30, for example, via the Internet. The data center 70 is configured to manage information of a plurality of mobile terminals (for example, smartphones) 80. The information of the mobile terminal 80 is registered in the data center 70, and includes information on the vehicle 50 of the user who owns the mobile terminal 80. This information includes, for example, the vehicle ID of the vehicle 50, and a driving schedule of the vehicle 50 including the scheduled departure time of the vehicle 50. The information registered in the data center 70 is transmitted to the server 30.

[0052] For example, when adjusting the balance between supply and demand of electricity, the server 10 of the electric power company E1 transmits a signal to each server 20 to request the upper aggregator E2 to participate in DR. This signal includes, for example, information on the area subject to DR and the period during which DR is implemented.

[0053] Upon receiving the above signal from the server 10, each server 20 of the upper level aggregator E2 transmits a request signal R1 to the server 30 of the lower level aggregator E3.

[0054] When the server 30 of the lower aggregator E3 receives the request signal R1 from the server 20 of the upper aggregator E2, the server 30 allocates a DR amount to each vehicle 50 that can participate in DR among the vehicles 50 under the jurisdiction of the lower aggregator E3. In this example, the DR amount for a vehicle 50 indicates the amount of power transfer requested to the vehicle 50. Then, the server 30 transmits a DR signal S1 for each vehicle 50. The DR signal S1 includes the ID (vehicle ID) of the vehicle 50 to which the signal is transmitted, the DR amount of the vehicle 50, the DR period, and other information regarding control of the charging relay 58. The vehicle ID, the DR amount, and the DR period may be stored in the storage device 32 of the server 30 as DR information.

[0055] When the vehicle 50 receives the DR signal S1, the vehicle 50 transmits vehicle information VI indicating the state of the vehicle 50 to the server 30. The vehicle information VI includes, for example, a vehicle ID, SOC information of the power storage device 110, and information such as a driving schedule (including a scheduled departure time) of the vehicle 50. Furthermore, the vehicle information VI includes, for example, information indicating whether or not the vehicle 50 can participate in a DR request (participation availability information) described below, information indicating the open / closed state of the charging relay 58, and information indicating the open / close history of the charging relay 58.

[0056] Fig. 3 is a diagram showing an example of a detailed configuration of vehicle 50. With reference to Fig. 3, vehicle 50 includes a motor generator (MG) 51, drive wheels 53, a power control unit (PCU) 54, a system main relay (SMR) 55, a charging relay 58, an inlet 59, a human machine interface (HMI) device 60, a communication device 62, a start switch 65, a power storage device 110, and an electronic control unit (ECU) 200.

[0057] The MG51 is, for example, a three-phase AC motor generator. The MG51 is driven by the PCU54 to generate a driving force for running the vehicle 50. The driving force for running is transmitted to the driving wheels 53 via a power transmission gear, thereby causing the vehicle 50 to run. Alternatively, the MG51 generates AC power during regenerative braking and supplies the generated power to the PCU54. The PCU54 converts the AC power into DC power and outputs it to the power storage device 110.

[0058] PCU 54 converts the power from the power storage device 110 and outputs the converted power to MG 51 to drive the vehicle 50, and also converts the power input from MG 51 during regenerative braking and outputs it to the power storage device 110 to charge the power storage device 110.

[0059] The SMR 55 is configured to be able to open and close in response to a control signal received from the ECU 200. The SMR 55 is provided on the power lines PL1, NL1, and switches the electrical connection state between the power storage device 110 and the PCU 54. The power line PL1 is a positive line that connects the positive terminal of the power storage device 110 and the positive terminal of the PCU 54. The power line NL1 is a negative line that connects the negative terminal of the power storage device 110 and the negative terminal of the PCU 54. When the SMR 55 is in a closed state, the power storage device 110 and the PCU 54 are in a conductive state. When the SMR 55 is in an open state, the power storage device 110 and the PCU 54 are in a cut-off state.

[0060] The charging relay 58 is configured to be able to open and close in response to a control signal received from the ECU 200. The charging relay 58 is provided on the power lines PL2, NL2. One end of the power line PL2 is connected to a position on the power line PL1 between the SMR 55 and the power storage device 110. The other end of the power line PL2 is connected to a positive terminal of the inlet 59. One end of the power line NL2 is connected to a position on the power line NL1 between the SMR 55 and the power storage device 110. The other end of the power line NL2 is connected to a negative terminal of the inlet 59. The charging relay 58 switches an electrical connection state between the power storage device 110 and the inlet 59. When the charging relay 58 is in a closed state, the power storage device 110 and the inlet 59 are in a conductive state. When the charging relay 58 is in an open state, the power storage device 110 and the inlet 59 are in an electrically disconnected state.

[0061] The inlet 59 has a structure that allows attachment of the connector 41 that is connected to the EVSE 40. When the connector 41 is attached to the inlet 59, a contact (not shown) provided in the inlet 59 comes into contact with a contact (not shown) provided in the connector 41, and the EVSE 40 and the inlet 59 are electrically connected. The EVSE 40 converts AC power from the power grid PG into DC power, and enables the supply of power to the vehicle 50 via the connector 41.

[0062] When connector 41 is attached to inlet 59 and charging relay 58 is in a closed state, power storage device 110 and power grid PG are electrically connected via inlet 59, connector 41, and EVSE 40, and thus external charging is possible in vehicle 50. On the other hand, when charging relay 58 is in an open state, power storage device 110 and power grid PG are electrically disconnected. In this case, external charging is not possible in vehicle 50.

[0063] The HMI device 60 receives operations by the user of the vehicle 50 and displays various screens. The HMI device 60 is operated, for example, to set a scheduled departure time of the vehicle 50. The HMI device 60 may display a screen for inquiring of the user whether or not the vehicle 50 can actually participate in the DR during the DR period specified in the DR signal S1. When a user operation indicating whether or not the vehicle 50 can participate in the DR is performed in response to the inquiry, information indicating whether or not the vehicle 50 can participate is stored in the memory of the ECU 200 as participation availability information.

[0064] The communication device 62 is configured to communicate with devices external to the vehicle 50. For example, the communication device 62 receives a DR signal S1 from the server 30 and transmits vehicle information VI to the server 30. The communication device 62 may be configured to be built into the ECU 200.

[0065] The start switch 65 is operated by a user to switch between starting and stopping the running system (power supply system) of the vehicle 50.

[0066] The power storage device 110 is configured to store electric power for traveling. The power storage device 110 is a secondary battery such as a lithium ion battery or a nickel metal hydride battery. The amount of stored power in the power storage device 110 is represented by, for example, the SOC.

[0067] The ECU 200 is a computer including a processor such as a CPU and a memory (neither of which are shown). The ECU 200 controls various devices of the vehicle 50, such as the MG 51, the PCU 54, the SMR 55, the charging relay 58, the HMI device 60, and the communication device 62.

[0068] ECU 200 is configured to, for example, control the open / closed state of SMR 55 and the open / closed state of charging relay 58. Furthermore, ECU 200 is configured to calculate the SOC of power storage device 110 in accordance with the temperature, voltage, and current of power storage device 110.

[0069] For example, when inlet 59 is connected to EVSE 40 and a request is made to start charging, ECU 200 controls charging relay 58 to a closed state and transmits a signal indicating the request to start charging to EVSE 40. When EVSE 40 receives the request to start charging, it converts AC power from power grid PG into DC power and supplies the DC power to vehicle 50, so that external charging is performed. After external charging starts, when the SOC of power storage device 110 reaches a threshold value (for example, an SOC set as a fully charged state), ECU 200 transmits a signal indicating a request to stop charging to EVSE 40 and controls charging relay 58 to an open state. As a result, when EVSE 40 receives the request to stop charging, it stops the supply of power to vehicle 50, so that external charging is terminated.

[0070] In this embodiment, the vehicle 50A is a V1G vehicle configured to be capable of performing only external charging. On the other hand, the vehicle 50B is a V2G vehicle configured to be capable of selectively performing external charging and external discharging. In this embodiment, both the vehicle 50A and the vehicle 50B have the configuration shown in FIG. 3, and during external charging, power is supplied from the power grid PG to the vehicle 50A via the EVSE 40A, and power is supplied from the power grid PG to the vehicle 50B via the EVSE 40B. During external power feeding, power is supplied from the vehicle 50B to the power grid PG via the EVSE 40B. The vehicle 50B may have a different configuration from the vehicle 50A in order to be capable of performing external power feeding.

[0071] Therefore, for example, when external charging is performed in each of vehicle 50A and vehicle 50B, the demand for power in the power grid PG can be increased. On the other hand, for example, when external power feeding is performed in vehicle 50B, the demand for power in the power grid PG can be decreased.

[0072] In this manner, by closing the charging relay 58 in order to perform external charging or external power supply, it is possible to participate in a DR request from the server 30.

[0073] On the other hand, when participating in a DR request, the number of times that the charging relay 58 is switched from a disconnected state to a connected state (hereinafter referred to as the number of times it is turned on) increases compared to when only normal charging and power supply processes that are not based on a DR request are performed, and this may cause deterioration of the charging relay 58.

[0074] Therefore, for example, it is conceivable to prohibit the switching operation of charging relay 58 when the number of times it is turned on exceeds a threshold value. However, if this is done, there is a possibility that the user will not be able to participate in subsequent DR requests and therefore will not be able to earn incentives. In addition, the relay will become more deteriorated as the number of times it is turned on increases, which may result in problems such as the inability to perform normal charging and power supply processes.

[0075] Therefore, in this embodiment, when a target vehicle among the multiple vehicles 50 receives power supply from the power grid PG in accordance with a request for an increased DR to charge the power storage device 110, if the number of times that the charging relay 58 is turned on exceeds an upper limit value, the target vehicle is instructed to maintain the connection state of the charging relay 58 until the charging process in accordance with the request for an increased DR is completed.

[0076] In this way, when the charging process is executed in response to a request for an increased DR, the connected state of charging relay 58 is maintained until the charging process is completed, so that the charging of power storage device 110 can be completed and an increase in the total number of times the relay is turned on can be suppressed. This makes it possible to suppress deterioration of charging relay 58 when the target vehicle is used as part of a VPP.

[0077] Hereinafter, the processes executed in each of the server 30 and the vehicle 50, and the information exchanged between the server 30 and the vehicle 50 will be described with reference to Fig. 4. Fig. 4 is a diagram for explaining specific processes executed in the processing device 33 of the server 30 and the ECU 200 of the vehicle 50.

[0078] 4, in the storage device 32 of the server 30, relay opening / closing information 36, relay history information 37, DR amount information 38, and relay control information 39 of each vehicle 50 are stored in association with the vehicle ID.

[0079] The relay open / close information 36 includes, for example, information indicating whether the charging relay 58 of each of the multiple vehicles 50 is in an open state or a closed state. The relay history information 37 includes information indicating the duration of the most recent closed state of the charging relay 58 of each of the multiple vehicles 50, and information indicating the total number of times the charging relay 58 has been turned on. The DR amount information 38 includes information indicating the amount of DR requests assigned to each of the multiple vehicles 50. The total number of times the charging relay 58 has been turned on includes, for example, the number of times the vehicle 50 has been turned on in response to a DR request since its manufacture, and the number of times the vehicle 50 has been turned on due to a normal charging process or power supply process not based on a DR request.

[0080] The relay control information 39 includes information related to the control of the charging relay 58 of each of the multiple vehicles 50. The information related to the control of the charging relay 58 includes, for example, information indicating a minimum duration of the on-state of the charging relay 58 during the charging process in accordance with the DR request, and information related to restrictions on the control of the charging relay 58 (for example, prohibition of switching, etc.) during the execution of the charging process in accordance with the DR request.

[0081] For example, when the processing device 33 of the server 30 receives a request signal R1 from the server 20, the processing device 33 transmits a DR signal S1 to each of the multiple vehicles 50.

[0082] When the ECU 200 of each vehicle 50 receives the DR signal S1 from the server 30 via the communication device 62, the ECU 200 transmits the vehicle information VI to the server 30 in sequence.

[0083] The processing device 33 of the server 30 updates the relay opening / closing information 36, the relay history information 37, and the DR amount information 38 using the received vehicle information VI. For example, the processing device 33 of the server 30 identifies a vehicle that can participate in DR among the multiple vehicles 50 using the participation possibility information, and updates the DR amount information 38 by allocating a DR amount to the identified vehicle. For example, the processing device 33 of the server 30 allocates the DR amount according to the SOC of the power storage device 110 mounted on the vehicle 50 that can participate in DR. For example, the processing device 33 allocates the difference between the current SOC of the power storage device 110 and the SOC corresponding to a fully charged state as the DR amount.

[0084] The processing device 33 of the server 30 updates the relay control information 39 using the relay opening / closing information 36 and the relay history information 37 of each vehicle 50. For example, when the number of times the charging relay 58 is turned on exceeds an upper limit value in any vehicle 50, the processing device 33 of the server 30 generates control information to maintain the on state of the charging relay 58 (i.e., prohibit switching to the off state) until the charging process in accordance with the request for the up-DR is completed, and updates the relay control information 39. The processing device 33 of the server 30 transmits the updated relay control information 39 to the target vehicle. In the vehicle 50 that receives the updated relay control information 39, when the charging process is performed in accordance with the request for the up-DR, the on state of the charging relay 58 is maintained until the charging process is completed. Therefore, even if the period during which the charging process is performed includes a period during which charging is stopped, the on state of the charging relay 58 is maintained.

[0085] Alternatively, the processor 33 of the server 30 sets and updates the minimum duration using the relay open / close information 36 and the relay history information 37. The method of setting the minimum duration will be described later.

[0086] Next, an example of processing executed by the server 30 of the power management system 1 according to the present embodiment will be described. Fig. 5 is a flowchart showing an example of processing executed by the server 30 of the power management system 1 according to the present embodiment. A series of processing shown in these flowcharts is repeatedly executed by the server 30 at every predetermined control period.

[0087] In step (hereinafter, step is abbreviated as S) 100, the server 30 determines whether or not there is a request for an upward DR. For example, the server 30 determines that there is an upward DR request when it receives a request signal R1 including an upward DR request from the server 20. Note that an upward DR request is made, for example, when it is predicted that the amount of power that can be supplied in the power grid PG will be greater than the amount of power demand after a predetermined time has elapsed. If it is determined that there is an upward DR request (YES in S100), the process proceeds to S102.

[0088] In S102, the server 30 acquires relay opening / closing information, relay history information, and relay control information from the multiple vehicles 50. The server 30 receives vehicle information VI from the multiple vehicles 50, for example, by transmitting a DR signal S1 to each of the multiple vehicles 50, and updates the information stored in the storage device 32 using the received information. The server 30 acquires relay opening / closing information, relay history information, and relay control information using the updated information. Thereafter, the process proceeds to S104.

[0089] In S104, the server 30 identifies a vehicle that will have its charging relay 58 turned on in response to the request for the increased DR among the multiple vehicles 50. The server 30 identifies the vehicle that will have its charging relay 58 turned on in response to the request for the increased DR by, for example, acquiring the vehicle ID of the vehicle that will have its charging relay 58 turned on in response to the request for the increased DR using participation possibility information included in the vehicle information VI received from the multiple vehicles 50. Thereafter, the process proceeds to S106.

[0090] In S106, the server 30 determines whether or not there is any vehicle among the identified vehicles 50 whose number of times the charging relay 58 has been turned on exceeds an upper limit value. As the upper limit value, for example, a predetermined value may be set. When the server 30 determines that there is any vehicle among the identified vehicles 50 whose number of times the charging relay 58 has been turned on exceeds the upper limit value (YES in S106), the process proceeds to S108.

[0091] In S108, the server 30 selects the vehicle determined as the vehicle whose number of times the charging relay 58 is turned on exceeds the upper limit as the vehicle whose charging process in accordance with the request for the increased DR will be maintained in the on state until the charging process in accordance with the request for the increased DR is completed. That is, the server 30 updates the relay control information corresponding to the vehicle ID of the vehicle determined as the vehicle whose number of times the charging relay 58 is turned on exceeds the upper limit by adding control information indicating that the charging relay 58 will be maintained in the on state until the execution period ends when the charging process is executed in accordance with the request for the increased DR. Thereafter, the process proceeds to S110. Also, if there is no vehicle whose number of times the charging relay 58 is turned on exceeds the upper limit among the identified vehicles 50 (NO in S106), the process proceeds to S110.

[0092] In S110, the server 30 determines whether or not there is a vehicle whose most recent charging time exceeds a threshold among the vehicles identified as vehicles that will turn on the charging relay 58 in response to the upward DR request. The threshold is a value for determining whether the most recently performed charging process was a long-term charge, and is, for example, a predetermined value. For example, the server 30 may acquire information about the most recent charging time from the vehicle 50 separately from the vehicle information VI or as information included in the vehicle information VI, or may acquire the most recent duration of the on state of the charging relay 58 as the most recent charging time. If it is determined that there is a vehicle whose most recent charging time exceeds the threshold among the identified vehicles (YES in S110), the process proceeds to S112.

[0093] In S112, the server 30 sets the minimum duration of the charging relay 58 corresponding to the vehicle whose most recent charging time has exceeded the threshold to a time shortened by a predetermined time. The server 30 updates the relay control information using the set minimum duration. The initial value of the minimum duration is, for example, a predetermined value. Thereafter, the process proceeds to S114. Also, if it is determined that there is no vehicle whose most recent charging time has exceeded the threshold (NO in S110), the process proceeds to S114.

[0094] In S114, the server 30 selects a vehicle whose charging relay 58 can be turned off during the execution of the charging process in accordance with the request for the upward DR, using the number of times the charging relay 58 is turned on. For example, the server 30 selects, from among the vehicles 50 identified in S104, a vehicle 50 whose number of times the charging relay 58 is turned on is less than a threshold value, as a vehicle whose charging relay 58 can be turned off during the execution of the charging process in accordance with the request for the upward DR.

[0095] In S116, the server 30 adjusts the DR request amount of each vehicle participating in the request for the up-charge DR. For example, when there is a vehicle that cannot realize the initially allocated DR request amount due to the setting of a vehicle that maintains the on state of the charging relay 58 during the execution period of the charging process, a vehicle whose minimum duration has been shortened, and a vehicle that can turn off the charging relay 58 during the execution period of the charging process, the server 30 changes the initially allocated DR request amount to a DR request amount that can be realized by the vehicle that cannot realize the initially allocated DR request amount, and allocates the shortfall due to the change to another vehicle. The other vehicle may be one vehicle or multiple vehicles. Note that the server 30 does not adjust the initially allocated DR request amount when all of the vehicles can realize the initially allocated DR request amount. Thereafter, the process proceeds to S118.

[0096] In S118, the server 30 transmits the updated relay control information to each vehicle 50. When the vehicle 50 receives the updated relay control information and participates in the request for the upward DR, the vehicle 50 controls the charging relay 58 using the updated relay control information.

[0097] The operation of the power management system 1 according to the present embodiment based on the above-described structure and flowchart will be described.

[0098] For example, when the amount of power that can be supplied by the power company E1 is greater than the amount of power demand, or when it is predicted that the amount will be greater, a request for an upward DR to increase the amount of power demand is made to the upper aggregator E2. Upon receiving the request for an upward DR from the power company E1, the upper aggregator E2 transmits a request signal R1 including the request for an upward DR to the lower aggregator E3.

[0099] In the server 30 of the lower aggregator E3, when the request signal R1 includes a request for an upward DR (YES at S100), a DR signal S1 is transmitted to multiple vehicles 50 included in the vehicle group 5, and relay opening / closing information, relay history information, and relay control information are acquired from the multiple vehicles 50 (S102).

[0100] Using the participation possibility information included in the acquired vehicle information VI, the vehicles that will turn on the charging relay 58 in response to the DR request are identified (S104). Furthermore, it is determined whether or not there is a vehicle among the identified vehicles that has turned on the charging relay 58 the number of times that exceeds an upper limit (106).

[0101] If there is a vehicle whose charging relay 58 has been turned on more than the upper limit, that vehicle is selected as a vehicle whose charging relay 58 will remain on until the charging process in accordance with the DR request is completed (S108).

[0102] Furthermore, it is determined whether or not there is a vehicle among the identified vehicles whose most recent charging time exceeds a threshold value (S110). If there is a vehicle whose most recent charging time exceeds the threshold value, the minimum duration of the vehicle is shortened by a predetermined time and set (S112). Furthermore, from among the identified vehicles, a vehicle whose charging relay 58 can be turned off during the execution period of the charging process according to the DR request is selected using the number of times the charging relay 58 is turned on (S114).

[0103] Then, the DR request amount for each of the identified vehicles 50 is set (S116), and the updated relay control information is transmitted to each vehicle 50 (S118).

[0104] In each vehicle 50 to which a DR request amount is allocated, external charging is performed. When a vehicle is selected as a vehicle for which the charging relay 58 is to be kept in the on state, the charging relay 58 is kept in the on state until the execution period of the charging process in the DR request time zone has elapsed, even if the execution period includes a period during which charging is suspended. Therefore, an increase in the number of times the charging relay 58 is turned on is suppressed.

[0105] Furthermore, in a vehicle whose most recent charging time exceeds the threshold, the minimum duration is shortened, so that the opening and closing operation of the charging relay 58 is performed with good responsiveness to changes in the DR request amount. In particular, the demand for electric power is adjusted by the opening and closing operation of the charging relay 58 of a vehicle that is turned on less frequently in response to changes in the DR request amount, so that the occurrence of a bias in which the number of times the charging relay 58 is turned on increases in some of the multiple vehicles 50 is suppressed.

[0106] As described above, according to the power management system 1 of the present embodiment, when a charging process is executed in response to a request to increase the demand amount, the connected state of the charging relay 58 is maintained until the charging process is completed. Even if a period during which the charging process is executed in response to a request for an increased DR includes a period during which the charging of the power storage device 110 is suspended, the on state of the charging relay 58 is maintained. Therefore, the charging of the power storage device 110 can be completed and an increase in the total number of on times can be suppressed. This makes it possible to suppress deterioration of the charging relay 58 when the target vehicle is used as part of a VPP. Therefore, it is possible to provide a power management system that suppresses an increase in the number of switching times of the relay that switches the connection state between the power grid and the on-board power storage device.

[0107] Furthermore, since charging relay 58 is controlled so that the duration of the connection state during the execution of the charging process in accordance with the request for the increased DR does not fall below the minimum duration, it is possible to prevent charging relay 58 from being turned on and off at intervals shorter than the minimum duration, and therefore it is possible to prevent an increase in the total number of times the relay is turned on.

[0108] Furthermore, when the previous charging time is greater than the threshold value, the minimum duration is set to be shorter than when the previous charging time is less than the threshold value, so that the charging process can be stopped with good responsiveness in response to a DR request.

[0109] The following describes modified examples.

[0110] In the above embodiment, the upper limit value of the number of on-states and the initial value of the minimum duration are described as predetermined values. However, for example, at least one of the upper limit value of the number of on-states and the minimum duration of the on-state may be set using the charging power from the EVSE 40 connected to each vehicle 50. The server 30 acquires information about the charging power of the EVSE 40 when acquiring the vehicle information VI from each vehicle 50. The server 30 sets the upper limit value and the minimum duration corresponding to each vehicle 50 using the acquired charging power. The server 30 may set the upper limit value and the minimum duration using, for example, a map, table, formula, or function indicating the relationship between the charging power and the upper limit value and the minimum duration, and the acquired charging power. The relationship between the charging power and the upper limit value and the minimum duration may be such that, for example, the higher the charging power, the higher the load on the relay caused by switching to the on state once is, so that the upper limit value is lowered and the minimum duration is extended.

[0111] Fig. 6 is a flowchart showing an example of processing executed by the server 30 of the power management system 1 according to the modified example. The flowchart shown in Fig. 6 differs from the flowchart shown in Fig. 5 in that it further includes processing of S200, and the other processing is the same as the processing described using Fig. 5 except as described below, and the same step numbers are assigned to these processing. Therefore, detailed description of these processing will not be repeated.

[0112] After the vehicle that has its charging relay turned on is identified (S104), the process proceeds to S200.

[0113] In S200, the server 30 sets an upper limit value of the on-count and a minimum duration time according to the charging power of each identified vehicle 50. Note that the method of acquiring the charging power of each vehicle 50 and the method of setting the upper limit value of the on-count and the minimum duration time are as described above, and therefore detailed description thereof will not be repeated.

[0114] In this way, the upper limit value and the minimum duration are set according to the charging power by the EVSE 40, so that the charging process can be stopped with good responsiveness to a request while suppressing an increase in the total number of times the relay is turned on. Note that, although the flowchart in Fig. 6 shows an example in which both the upper limit value and the minimum duration are set using the charging power, it is also possible to set either one of the upper limit value or the minimum duration.

[0115] Furthermore, in the above embodiment, a vehicle capable of turning off the charging relay is selected using the number of times the charging relay 58 is turned on, and the selected vehicle is used to respond to changes in the DR request amount, but in the case of adjusting the demand amount of power according to a request for an increased DR, a vehicle with the number of times the charging relay 58 is turned on greater than a threshold value (<upper limit value) may be used as a vehicle for adjusting the demand amount using a predetermined adjustment capacity. Note that the predetermined adjustment capacity is an adjustment capacity with a predetermined response time, and more specifically, includes an adjustment capacity with a longer response time than any of a plurality of adjustment capacities with different response times for adjusting the demand amount according to a DR request.

[0116] Furthermore, in the above-described embodiment, a vehicle for which the charging relay 58 can be turned off is selected using the number of times the charging relay 58 is turned on, and the selected vehicle is used to respond to changes in the DR request amount. However, when adjusting the demand for electricity in accordance with a request for an increased DR, a V1G vehicle whose charging power differs from the most recent charging power by less than a threshold value may be selected as the vehicle for maintaining the charging relay 58 in the on state until the charging process is completed.

[0117] 7 is a flowchart showing another example of the processing executed by the server 30 of the power management system 1 according to the modified example. A series of processing shown in these flowcharts is repeatedly executed by the server 30 at every predetermined control period.

[0118] The flowchart shown in Fig. 7 differs from the flowchart shown in Fig. 5 in that it further includes processes of S300, S302, S304, S306, S308, and S310 instead of the processes of S110, S112, and S114, and the other processes are the same as the processes described using Fig. 5 except as described below, and are assigned the same step numbers. Therefore, detailed description of those processes will not be repeated.

[0119] If there is no vehicle whose charging relay 58 has been turned on more than the upper limit number of times (NO in S106), or after a vehicle has been selected that will maintain the charging relay 58 in the on state until the charging process is completed in accordance with a request for an increased DR (S108), processing proceeds to S300.

[0120] In S300, server 30 determines whether there is a vehicle whose charging relay 58 has been turned on a number of times that exceeds a threshold value. The threshold value is not particularly limited, and may be a value smaller than an upper limit value that can determine that the vehicle is one of multiple vehicles 50 whose charging relay 58 has been turned on a relatively large number of times. If it is determined that there is a vehicle whose charging relay 58 has been turned on a number of times that exceeds the threshold value (YES in S300), processing proceeds to S302.

[0121] In S302, the server 30 determines whether the adjustment capability for adjusting the demand for power in accordance with the request for an upward DR is the adjustment capability corresponding to the tertiary-2.

[0122] The adjustment capability for adjusting the demand for electric power includes a plurality of predetermined adjustment capabilities with different response times. For example, the adjustment capabilities include a primary adjustment capability, a secondary adjustment capability, a tertiary adjustment capability (1) (hereinafter referred to as "tertiary-1"), and a tertiary adjustment capability (2) (hereinafter referred to as "tertiary-2"). These adjustment capabilities are set with different response times, for example, the response time of the primary adjustment capability is within 10 seconds, the response time of the secondary adjustment capability is within 5 minutes, the response time of the tertiary-1 is within 15 minutes, and the response time of the tertiary-2 is within 45 minutes. In other words, the tertiary-2 is an adjustment capability that has a longer response time than any of the response times of the other adjustment capabilities. For example, the server 30 sets the adjustment capability of the demand for electric power according to a request for upward DR in response to a request for adjustment capability from the server 20, and stores information (adjustment capability information) about the set adjustment capability in the storage device 32. The server 30 uses the adjustment capacity information to determine whether or not the adjustment capacity for adjusting the demand for power in accordance with the DR request is an adjustment capacity corresponding to the tertiary-2. The adjustment capacity may be set in advance for each jurisdiction of the server 30, for example. Also, in this modified example, the case where the adjustment capacity of each vehicle 50 is the same adjustment capacity has been described as an example, but, for example, a different adjustment capacity may be set for each vehicle 50. If it is determined that the adjustment capacity for adjusting the demand for power in accordance with the DR request is an adjustment capacity corresponding to the tertiary-2 (YES in S302), the process proceeds to S304.

[0123] In S304, the server 30 sets the vehicle whose charging relay 58 is turned on more than the threshold as a selection candidate (participation target for the request for the up-DR). Then, the process proceeds to S308. If it is determined that the adjustment capacity for adjusting the demand for power according to the request for the up-DR is not the adjustment capacity corresponding to the tertiary-2 (NO in S302), the process proceeds to S306.

[0124] In S306, server 30 excludes a vehicle whose charging relay 58 has been turned on more than a threshold value from the selection candidates. Server 30 may, for example, update the participation possibility information corresponding to the vehicle ID of the vehicle to information indicating non-participation. Then, the process proceeds to S308.

[0125] In S308, the server 30 determines whether or not there is a vehicle whose charging power has changed little from the most recent charging power. If there is a vehicle whose charging power has changed little from the most recent charging power and the current charging power is equal to or less than a threshold value among the multiple vehicles 50, the server 30 determines that there is a vehicle whose charging power has changed little from the most recent charging power. If it is determined that there is a vehicle whose charging power has changed little from the most recent charging power (YES in S308), the process proceeds to S310.

[0126] In S310, the server 30 selects the V1G vehicle among the vehicles with a small change from the most recent charging power as a vehicle for which the charging relay 58 is to be kept in the on state until the charging process according to the request for the increased DR is completed. Then, the process proceeds to S116. Also, when it is determined that there is no vehicle with a small change from the most recent charging power (NO in S308), the process proceeds to S116.

[0127] The operation of the power management system 1 according to this modified example based on the above flowchart will be described.

[0128] For example, assume that the upper aggregator E2 receives a request for an upward DR from the power company E1 and transmits a request signal R1 including the request for the upward DR to the lower aggregator E3. The request signal R1 includes information requesting that the adjustment capability of the demand for electricity using the group of vehicles 5 be set to tertiary-2.

[0129] In the server 30 of the lower aggregator E3, when the request signal R1 includes a request for an upward DR (YES at S100), a DR signal S1 is transmitted to multiple vehicles 50 included in the vehicle group 5, and relay opening / closing information, relay history information, and relay control information are acquired from the multiple vehicles 50 (S102).

[0130] Using the participation possibility information included in the acquired vehicle information VI, the vehicles that will turn on the charging relay 58 in response to the DR request are identified (S104). Furthermore, it is determined whether or not there is a vehicle among the identified vehicles that has turned on the charging relay 58 the number of times that exceeds an upper limit (106).

[0131] If there is a vehicle whose charging relay 58 has been turned on more than the upper limit (YES in S106), that vehicle is selected as a vehicle that will maintain the charging relay 58 in the on state until the charging process in accordance with the request for the increased DR is completed (S108).

[0132] Furthermore, if there is a vehicle whose charging relay 58 is turned on more than a threshold value (<upper limit value) and the adjustment capability is tertiary-2 (YES in S302), the vehicle 50 whose on-time exceeds the threshold value is also set as a selection candidate (S304).

[0133] Furthermore, if there is a vehicle whose charging power has changed little from the most recent charging power (YES in S308), if it is a V1G vehicle, it is selected as the vehicle whose charging relay 58 will be kept in the on state until the charging process in accordance with the request for increased DR is completed, even if the number of times it has been turned on has not exceeded the upper limit (S310).

[0134] Then, the DR request amount for each of the identified vehicles 50 is set (S116), and the updated relay control information is transmitted to each vehicle 50 (S118).

[0135] In each vehicle 50 to which a DR request amount is allocated, external charging is performed. When a vehicle is selected as a vehicle for which the charging relay 58 is to be kept in the on state, the charging relay 58 is kept in the on state until the execution period of the charging process in the DR request time period has elapsed. Therefore, an increase in the number of times the charging relay 58 is turned on is suppressed.

[0136] In addition, the demand for electric power is adjusted by the opening and closing operation of the charging relay 58 of vehicles and V2G vehicles that are turned on a small number of times in response to changes in the DR request amount, so the demand for electric power can be adjusted according to the DR request amount. In addition, since it is assumed that only external charging is performed in V1G vehicles, relays with lower durability (lower upper limit value for the number of times that the relays are turned on) may be used in V2G vehicles that can perform both external charging and external power supply. Therefore, by suppressing an increase in the number of times that the charging relay 58 of the V1G vehicles is turned on, it is possible to suppress the occurrence of a bias in the number of times that the charging relay 58 is turned on across the entire vehicle 50.

[0137] According to this modification, when the demand amount is adjusted using an adjustment capability with a long response time, the charging relay 58 may be turned on less frequently than when the demand amount is adjusted using an adjustment capability with a short response time. Therefore, by selecting a vehicle with a larger number of on times than a threshold as a vehicle for adjusting the demand amount using the tertiary-2, it is possible to suppress an increase in the total number of on times of the charging relay 58 of the vehicle 50.

[0138] Furthermore, in vehicles where there is little change from the most recent charging power, the charging relay 58 is maintained in a connected state during the period in which the charging process is performed in accordance with the request for the increased DR, thereby suppressing an increase in the total number of times the charging relay 58 is turned on.

[0139] Furthermore, in the above-described embodiment, a configuration in which only charging relay 58 is provided between power storage device 110 and inlet 59 has been described as an example, but a configuration in which SMR 55 and charging relay 58 are provided between power storage device 110 and inlet 59 may also be used.

[0140] Fig. 8 is a diagram showing an example of a detailed configuration of a vehicle in a modified example. Vehicle 50 shown in Fig. 8 differs from vehicle 50 shown in Fig. 3 in that one end of power line PL2 is connected at a position between PCU 54 and SMR 55 on power line PL1, and one end of power line NL2 is connected at a position between PCU 54 and SMR 55 on power line NL1. The other configurations of vehicle 50 shown in Fig. 8 are similar to those of vehicle 50 shown in Fig. 3 and are assigned the same reference numerals. Therefore, detailed description thereof will not be repeated.

[0141] The vehicle 50 shown in Fig. 8 differs from the vehicle 50 shown in Fig. 3 in that, when external charging is performed, in addition to closing the charging relay 58, the SMR 55 is also closed. In this case, the server 30 determines whether or not there is a vehicle among the multiple vehicles 50 in which the greater of the number of times the charging relay 58 is turned on and the number of times the SMR 55 is turned on exceeds an upper limit. Even in this manner, an increase in the number of times the charging relay 58 or the SMR 55 is turned on can be suppressed.

[0142] Furthermore, in the above embodiment, in the case where the storage device 110 is charged by receiving power supply from the power grid PG in any of the target vehicles among the multiple vehicles 50 in accordance with a request for an upward DR, when the number of times that the charging relay 58 is turned on exceeds an upper limit, the target vehicle is instructed to maintain the connection state of the charging relay 58 until the charging process in accordance with the request for the upward DR is completed. However, the DR request is not limited to a request for an upward DR, and the same applies to a request for a downward DR. For example, a request for a downward DR may be complied with by reducing the charge amount in any of the multiple vehicles 50. Therefore, even when a request for a downward DR is complied with, the storage device 110 may be charged by receiving power supply from the power grid PG in any of the target vehicles among the multiple vehicles 50. Therefore, by instructing the target vehicle to maintain the connection state of the charging relay 58 until the charging process in accordance with the request for the downward DR is completed when the number of times that the charging relay 58 is turned on exceeds an upper limit, an increase in the total number of times that the charging relay 58 is turned on can be suppressed.

[0143] The above-described modified examples may be implemented in whole or in part in appropriate combination.

[0144] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the scope and meaning equivalent to the claims. [Explanation of symbols]

[0145] 1 Power management system, 5 Vehicle fleet, 10,20,20A,30,30A,30B Server, 11 Power plant, 12 Power transmission and distribution equipment, 13,14 Smart meter, 31,62 Communication device, 32 Storage device, 33 Processing device, 36 Relay opening and closing information, 37 Relay history information, 38 DR amount information, 39 Relay control information, 40,40A,40B EVSE, 41 Connector, 50,50A,50B Vehicle, 51 MG, 53 Drive wheel, 54 PCU, 55 SMR, 58 Charging relay, 59 Inlet, 60 HMI device, 65 Start switch, 70 Data center, 80 Mobile terminal, 110 Energy storage device, 200 ECU, E1 Power company, E2 Upper aggregator, E3 Lower aggregator, PG Power grid.

Claims

1. A power management system that manages power exchanged between a Virtual Power Plant (VPP) connected to a power grid installed within a predetermined area and an area outside the power grid, the VPP being configured to be connectable and disconnectable to the power grid via a relay, and including a plurality of vehicles each equipped with a power storage device that can be charged by receiving power supply from the power grid; a server capable of communicating with the plurality of vehicles; The server, Obtaining a state of the relay for each of the plurality of vehicles; and when a number of times that the relay is turned on to change from a disconnected state to a connected state exceeds a first value in a target vehicle among a plurality of vehicles receiving power supply from the power grid in response to a request for an increase in demand for power in the power grid to charge the power storage device, the power management system instructs the target vehicle to maintain the connected state of the relay until the charging process in accordance with the request is completed.

2. The power management system according to claim 1 , wherein the period during which the charging process is performed includes a period during which charging of the power storage device is interrupted.

3. The power management system according to claim 1 , wherein the vehicle includes a control device that controls the relay so that a duration during which the relay is kept in a connected state during the charging process does not fall below a second value.

4. 4. The power management system according to claim 3, wherein the control device sets the second value to be smaller when the previous charging time is greater than a third value than when the previous charging time is less than the third value.

5. The power management system according to claim 3 , wherein the server sets at least one of the first value and the second value by using charging power in the charging process.

6. the server selects a vehicle having a number of on-times greater than a fourth value from among the plurality of vehicles as a vehicle for adjusting the demand amount using a predetermined adjustment power; The power management system according to any one of claims 1 to 5, wherein the predetermined adjustment capacity includes an adjustment capacity having a longer response time than any of a plurality of adjustment capacities having different response times for adjusting the demand amount in accordance with the request.

7. The power management system according to any one of claims 1 to 6, wherein the server selects a vehicle from among the plurality of vehicles that is capable of turning the relay off during a period in which the charging process is performed, using the number of times the relay is turned on.

8. The power management system according to any one of claims 1 to 7, wherein the server selects a vehicle whose difference between the charging power in the charging process and the most recent charging power is equal to or less than a threshold value as a vehicle for maintaining the connection state of the relay until the charging process is completed.

9. the plurality of vehicles includes a V1G vehicle that receives a unilateral supply of power from the power grid, The power management system according to claim 8, wherein the server selects a V1G vehicle whose difference between the charging power in the charging process and the most recent charging power is equal to or less than a threshold value as a vehicle for maintaining the connection state of the relay until the charging process is completed.

Images