Power system, control device, and power system control method

Abstract

To prevent a power storage device of a vehicle from becoming an over-discharged state when a power supply device cannot acquire an instruction based on DR information.SOLUTION: A power system stops discharging a battery 100 and charges the battery 100 if the battery 100 of a vehicle 50 is being discharged (reverse power flowing) when EVSE 40 is unable to acquire a DR instruction based on DR information transmitted from a server 30 from a HEMS 70 such as when communication between the HEMS 70 and the EVSE 40 is interrupted.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] In recent years, in order to maintain the supply and demand balance of electricity supplied from the power grid, attention has been focused on virtual power plants (VPPs) that integrate and control multiple distributed energy resources (DERs) as if they were a single power plant. JP 2020-156149 A (Patent Document 1) discloses that an aggregator server communicates with a consumer's energy management system (for example, a Home Energy Management System (HEMS)) via an EMS (Energy Management System) network, and the charging and discharging of an electric vehicle as a DER is performed by the HEMS. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-156149 A Summary of the Invention [Problem to be solved by the invention]

[0004] When a vehicle is used as a DER, the vehicle's power storage device is charged and discharged via a power supply device (EVSE: Electric Vehicle Supply Equipment). The EVSE is connected to a HEMS controller via a LAN (Local Area Network). The EVSE charges and discharges the vehicle's power storage device (battery) based on commands from the HEMS controller. The HEMS controller controls the EVSE based on DR (Demand Response) information received from an aggregator's server via a dedicated line or Internet line. The HEMS controller also functions as a gateway device that relays the dedicated line or Internet line and the LAN.

[0005] Since the HEMS controller and the EVSE are connected by a LAN, the communication may become unstable depending on the communication environment. In addition, the HEMS controller may temporarily not operate normally due to a bug in the HEMS controller. When the LAN communication becomes unstable or the HEMS controller temporarily does not operate normally, the EVSE cannot be controlled based on the DR information. For this reason, for example, when the DR information is a request for downward DR and the storage device is being discharged and reverse power flow is being performed, if the LAN communication becomes unstable and the EVSE cannot obtain a command to stop discharging, the discharge continues, and the vehicle's storage device may become over-discharged.

[0006] An object of the present disclosure is to prevent a power storage device of a vehicle from entering an over-discharge state when a power supply device (EVSE) cannot acquire a command based on DR information. [Means for solving the problem]

[0007] The power system of the present disclosure includes a vehicle equipped with a power storage device, a power supply device that transfers power between a power grid and the vehicle, a gateway device that acquires DR information transmitted from a server, a first communication device that communicates between the power supply device and the gateway device, and a control device. When reverse power flow is being performed from the vehicle via the power supply device, if the power supply device cannot acquire a command based on the DR information, the control device stops discharging from the power storage device and stops the reverse power flow.

[0008] According to this configuration, a vehicle equipped with a power storage device transfers power to and from a power grid via a power supply device. The gateway device acquires DR information transmitted from a server and communicates with the power supply device via a first communication device. When reverse power flow is being performed from the vehicle via the power supply device, if the power supply device cannot acquire a command based on the DR information, the control device of the power control system stops discharging from the power storage device and stops the reverse power flow.

[0009] When the communication state of the first communication device becomes unstable, for example, when a communication interruption occurs and the power supply device cannot obtain a command based on DR information from the gateway device, if reverse power flow is being performed from the vehicle via the power supply device, discharging from the power storage device is stopped and reverse power flow is stopped. Therefore, when the power supply device cannot obtain a command based on DR information, discharging from the power storage device is stopped, so that it is possible to prevent the power storage device from continuing to discharge and becoming in an over-discharged state. Note that, for example, even if the communication between the server and the gateway device becomes unstable and the gateway device cannot obtain DR information from the server, causing the power supply device to be unable to obtain a command based on DR information, discharging from the power storage device is stopped and the power storage device is prevented from becoming in an over-discharged state.

[0010] The control device may execute control to charge the power storage device from the power grid via the power supply device, in addition to stopping the reverse power flow.

[0011] According to this configuration, when the power supply device cannot obtain a command based on the DR information and the vehicle cannot be used as a DER, the vehicle's power storage device is charged, so that power can be stored for the next time the vehicle travels. In this case, the power storage device may be fully charged.

[0012] The power system may further include a second communication device that communicates between the vehicle and the power supply device, and the control device may be configured to stop the supply of power by the power supply device when communication by the second communication device is abnormal during charging after reverse power flow is stopped (discharge is stopped).

[0013] According to this configuration, when an abnormality occurs in communication by the second communication device, which communicates between the vehicle and the power supply device, such as when communication by the second communication device is interrupted and the power storage device cannot be charged properly, the supply of power by the power supply device is stopped, thereby protecting the power storage device from overcharging, etc.

[0014] The control device disclosed herein is a control device that controls a power supply device that transfers power between a vehicle equipped with a power storage device and a power grid. The control device includes a communication interruption detection unit that detects that the power supply device cannot acquire a command based on DR information from a gateway device that acquires DR information from a server, and a processing unit that stops discharging from the power storage device and stops the reverse power flow when the communication interruption detection unit detects that the command based on the DR information cannot be acquired while reverse power flow is being performed from the vehicle via the power supply device.

[0015] According to this configuration, a vehicle equipped with a power storage device receives and transmits power to and from a power grid via a power supply device. A control device that controls the power supply device detects, in a communication interruption detection unit, that the power supply device cannot obtain a command based on DR information from a gateway device that obtains DR information from a server. When reverse power flow is being performed from the vehicle via the power supply device, a processing unit of the control device stops discharging from the power storage device and stops the reverse power flow when the communication interruption detection unit detects that the command based on DR information cannot be obtained.

[0016] For example, when the communication state between the gateway device and the power supply device becomes unstable and the power interruption detection unit detects that the power supply device cannot obtain a command based on DR information from the gateway device, if reverse power flow is being performed from the vehicle via the power supply device, the processing unit stops discharging from the power storage device and stops the reverse power flow. Therefore, when the power supply device cannot obtain a command based on DR information, discharging from the power storage device is stopped, so that it is possible to prevent the power storage device from continuing to discharge and becoming in an over-discharged state. Note that, for example, even if the communication between the server and the gateway device becomes unstable and the gateway device cannot obtain DR information from the server, causing the power supply device to be unable to obtain a command based on DR information, discharging from the power storage device is stopped, and the power storage device is prevented from becoming in an over-discharged state.

[0017] Preferably, the processing unit may execute a process of charging the power storage device from the power grid via a power feeding device, simultaneously with stopping the reverse power flow.

[0018] According to this configuration, when the power supply device cannot obtain a command based on the DR information and the vehicle cannot be used as a DER, the vehicle's power storage device is charged, so that power can be stored for the next time the vehicle travels. In this case, the power storage device may be fully charged.

[0019] Preferably, the control device further includes a communication anomaly detection unit that detects an abnormality in communication between the vehicle and the power supply device, and the processing unit of the control device may be configured to stop the supply of power by the power supply device when the communication anomaly detection unit detects an abnormality in communication between the vehicle and the power supply device while charging is being performed after the reverse flow is stopped.

[0020] According to this configuration, if an abnormality occurs in communication between the vehicle and the power supply device and the power storage device cannot be charged properly, the power supply device stops sending and receiving power, thereby protecting the power storage device from overcharging, etc.

[0021] The control method of the power system disclosed herein is a control method of a power system including a vehicle equipped with a power storage device, a power supply device that transfers power between a power system and the vehicle, a gateway device that acquires DR information transmitted from a server, and a communication device that communicates between the power supply device and the gateway device. The control method detects that the power supply device cannot acquire a command based on the DR information while performing reverse power flow from the vehicle via the power supply device, and when the power supply device detects that it cannot acquire a command based on the DR information, stops discharging from the power storage device and stops the reverse power flow.

[0022] According to this power system control method, when reverse power flow is being performed from a vehicle via a power supply device, if, for example, communication via a communication device becomes unstable and it is detected that the power supply device cannot obtain commands based on DR information, discharge from the storage device is stopped and reverse power flow is stopped.

[0023] Therefore, when the power supply device cannot obtain a command based on the DR information, discharging from the storage device is stopped and the storage device is charged from the power grid, thereby preventing the storage device from continuing to discharge and becoming over-discharged.

[0024] The control method may include detecting that the power supply device cannot obtain a command based on DR information while performing reverse power flow from the vehicle via the power supply device, and when the power supply device detects that it cannot obtain a command based on the DR information, stopping discharge from the power storage device to stop reverse power flow and charging the power storage device from the power grid via the power supply device. In this way, when the power supply device cannot obtain a command based on the DR information, discharging from the power storage device is stopped and the power storage device is charged from the power grid, so that it is possible to prevent the power storage device from continuing to discharge and becoming overdischarged, and it is possible to store power for the next time the vehicle travels. Effect of the Invention

[0025] According to the present disclosure, when a power supply device cannot obtain a command based on DR information, it is possible to prevent a power storage device of a vehicle from entering an over-discharge state. [Brief description of the drawings]

[0026] [Figure 1] 1 is a schematic overall configuration diagram of a power system according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a diagram showing an example of a communication mode of a server managed by a lower aggregator. [Diagram 3] FIG. 2 is a diagram showing functional blocks configured in a control unit of the EVSE. [Figure 4] 5 is a flowchart showing an example of a communication abnormality control process executed by a control unit of the EVSE. 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 schematic overall configuration diagram of a power system 1 according to this embodiment. The power system 1 of this embodiment is a VPP system. The VPP system is a mechanism for bundling a large number of DERs using advanced energy management technology that utilizes IoT (Internet of Things) and remotely and centrally controlling these DERs to function as if they were a single power plant. In the power system 1 of this embodiment, a vehicle equipped with a power storage device is used as the DER.

[0029] The power system 1 includes a plurality of electric vehicles and a plurality of electric power supply devices (EVSEs). The number of electric vehicles and EVSEs included in the power system 1 is each independently arbitrary, and may be 10 or more, or may be 100 or more. The power system 1 may include at least one of a non-public EVSE (e.g., a home EVSE) that can be used only by specific users, and a public EVSE that can be used by an unspecified number of users.

[0030] The power system 1 includes a power company E1, a higher-level aggregator E2, and a lower-level aggregator E3. The power company E1 serves as a power generation business operator, a power transmission and distribution business operator, an electricity retailer, etc. The lower-level aggregator E3 is a resource aggregator that directly concludes VPP service contracts with consumers and controls resources (DERs). The higher-level aggregator E2 is, for example, an aggregation coordinator that aggregates the power controlled by the resource aggregator (lower-level aggregator) E3 and directly trades power with the power company E1.

[0031] 2 is a diagram showing an example of a communication mode of the server 30 managed by a lower aggregator (resource aggregator) E3. The power system 1 includes a power system PG, a smart meter 13, the server 30, an EVSE 40, a vehicle 50, an EMS network 60, and a HEMS 70.

[0032] Vehicle 50 is configured to be capable of running using electric power stored in a power storage device (battery) 100. Vehicle 50 according to this embodiment is an electric vehicle (BEV: Battery Electric Vehicle) that does not include an engine (internal combustion engine), but may also be a plug-in hybrid electric vehicle (PHEV: Plug-in Hybrid Electric Vehicle). Battery 100 is configured, for example, by a secondary battery such as a lithium ion battery or a nickel metal hydride battery.

[0033] The vehicle 50 includes an ECU (Electronic Control Unit) 110. The ECU 110 is configured to perform charging control and discharging control of the battery 100. The vehicle 50 includes a monitoring module (not shown) that monitors the state of the battery 100. The monitoring module includes various sensors that detect the state (e.g., voltage, current, and temperature) of the battery 100, and outputs the detection results to the ECU 100. Note that the monitoring module may be a BMS (Battery Management System) that further has a SOC (State Of Charge) estimation function, a SOH (State Of Health) estimation function, a cell voltage equalization function, a diagnosis function, and a communication function in addition to the above sensor functions.

[0034] The vehicle 50 includes an inlet 120 and a charge / discharge circuit 130 for charging and discharging the battery 100. The inlet 120 is configured to exchange electric power with the outside of the vehicle 50. The inlet 120 is configured to be connectable to a connector 45 of a charge / discharge cable 44. When the connector 45 of the charge / discharge cable 44 connected to the main body of the EVSE 40 is connected (plugged in) to the inlet 120 of the vehicle 50, the vehicle 50 enters a state in which it can be charged and discharged (i.e., a state in which it can exchange electric power with the EVSE 40).

[0035] The EVSE 40 of this embodiment is a power supply device compatible with V2G (Vehicle to Grid) (or V2H (Vehicle to Home)), and converts AC power supplied from a power system PG into DC power to charge the battery 100. The EVSE 40 is also capable of converting DC power discharged from the battery 100 into AC power and supplying it to the power system PG (reverse power flow). The EVSE 40 includes a control unit 41, a communication unit 42, a power supply circuit 43, and a charge / discharge cable 44. The control unit 41, the communication unit 42, and the power supply circuit 43 are provided in the main body of the EVSE 40. The charge / discharge cable 44 is connected to the main body of the EVSE 40. The charge / discharge cable 44 may be always connected to the main body of the EVSE 40, or may be detachable from the main body of the EVSE 40. The charge / discharge cable 44 has a connector 45 at its tip and includes a power line inside. The control unit 41 controls the communication unit 42 and the power supply circuit 43.

[0036] The power system PG is a power network provided by the power company E1. The power system PG is electrically connected to a plurality of EVSEs (including the EVSE 40) and supplies AC power to each EVSE. The smart meter 13 is configured to measure the amount of power every predetermined time (for example, every 30 minutes), store the measured amount of power, and transmit it to a server 10 (see FIG. 1 ) managed by the power company E1. The smart meter 13 also transmits the measured amount of power to a server 30 managed by the lower aggregator E3.

[0037] The server 30 managed by the lower aggregator E3 communicates with the vehicle 50 and the HEMS 70 via the EMS network 60. The EMS network 60 may be a dedicated line or an Internet line such as a VPN (Virtual Private Network). The communication device 140 mounted on the vehicle 50 communicates with the server 30 via the EMS network 60. The communication device 140 is configured to communicate with the communication unit 42 of the EVSE 40 via a charge / discharge cable 44. The communication method between the EVSE 40 and the vehicle 50 is arbitrary, and may be, for example, a Controller Area Network (CAN) or a Control Pilot Line (CPLT) communication using a Power Line Communication (PLC). The communication between the vehicle 50 and the EVSE 40 may be wireless communication using Bluetooth (registered trademark) or the like. The communication unit 42 and the communication device 140 that communicate between the EVSE 40 and the vehicle 50 correspond to an example of a "second communication device" in the present disclosure.

[0038] The server 30 includes a control device 31, a storage device 32, and a communication device 33. The control device 31 includes a processor and a memory, and is configured to perform predetermined information processing and control the communication device 33. The storage device 32 is configured to be able to store various types of information. The communication device 33 includes various communication I / Fs, and is configured to communicate with the outside via the EMS network 60.

[0039] The HEMS 70 is a controller that controls home electric appliances, and in this embodiment, it also controls the EVSE 40 based on DR information from the server 30 and functions as a gateway device that relays between the server 30 and the EVSE 40. In this embodiment, the EVSE 40 is a non-public EVSE (for example, a home EVSE) that can be used only by specific users, so the HEMS 70 is used. If the EVSE 40 is a public EVSE that can be used by an unspecified number of users, a Factory Energy Management System (FEMS) or Building Energy Management System (BEMS) installed in a business establishment (for example, a factory or commercial facility) may be used instead of the HEMS 70.

[0040] The HEMS 70 includes a control device 71, a storage device 72, and a communication device 73. The control device 71 includes a processor and a memory, and is configured to perform predetermined information processing and control the communication device 73. The storage device 72 is configured to be able to store various information. The communication device 73 includes various communication I / Fs and is configured to communicate with the outside via the EMS network 60. The communication device 73 is also connected to the communication unit 42 of the EVSE 40 via a LAN, and the HEMS 70 also functions as a gateway device that relays between the EMS network 60 and the LAN (relays between the server 30 and the EVSE 40). The LAN may be a wired LAN or a wireless LAN using Wi-Fi. The communication device 73 and the communication unit 42 that communicate between the HEMS 70 and the EVSE 40 correspond to an example of a "first communication device" in the present disclosure.

[0041] With reference to FIG. 1, electric power company E1 constructs a power grid (power system PG shown in FIG. 1) by a power plant 11 and a power transmission and distribution facility 12, and maintains and manages the power system PG by a server 10. The power plant 11 includes a power generation device and is configured to supply 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.

[0042] The power company E1 can adjust the power of the power system PG by cooperating with the aggregator. The upper aggregator (aggregation coordinator) E2 operates and manages a server (e.g., servers 20, 20A, 20B) for each business operator. The lower aggregator (resource aggregator) E3 operates and manages a server (e.g., servers 30, 30A, 30B) for each business operator.

[0043] In this embodiment, the server 10 of the electric power company E1 issues a DR request to the upper aggregator E2 (its server) based on the power demand forecast of the power system PG, specifying the time period (date and time) and amount of power for executing DR. When power demand is tight, a downward DR request is issued, and when there is a power surplus, an upward DR request is issued. The upper aggregator E2 (its server) transmits the DR request information and the power trading conditions to the lower aggregator E3 (its server). The lower aggregator E3 (its server) transmits the DR information to contracted consumers and controls the DER to meet the conditions, taking into account the characteristics and scale of the DER.

[0044] In this embodiment, the server 10 of the electric power company E1, the servers (servers 20, 20A, 20B) of the upper aggregator E2, and the servers (servers 30, 30A, 30B) of the lower aggregator E3 are configured to communicate information via an EMS network 60 (see FIG. 2). As shown in FIG. 2, the servers (servers 30, 30A, 30B) of the lower aggregator E3 communicate information with each consumer via the EMS network 60.

[0045] 1, a vehicle 50A and an EVSE 40A have almost the same configuration as the vehicle 50 and the EVSE 40. The EVSE 40A is connected to the power grid PG via a smart meter 13A. The EVSE 40A is not connected to the server 30 via a HEMS or the like, and is controlled by the vehicle 50A (its ECU).

[0046] With reference to FIG. 2, when the HEMS 70 receives information on the DR request via the EMS network 60, the EVSE 40 determines whether the vehicle 50 can respond to the DR request. For example, the EVSE 40 acquires vehicle information such as the vehicle 50's action schedule (departure date and time, etc.) and the SOC of the battery 100 by communicating with the vehicle 50. The EVSE 40 transmits the acquired vehicle information to the HEMS 70. The HEMS 70 determines whether the vehicle 50 can respond to the DR request transmitted from the server 30 based on the received vehicle information. If the vehicle 50 can respond to the DR request, the HEMS 70 transmits a request to participate in the DR request to the server 30. Note that the vehicle 50 (EUC 110) may determine whether the vehicle 50 can respond to the DR request through communication between the vehicle 50 and the server 30 and transmit the request to participate in the DR to the server 30. Also, a consumer may check the information on the DR request displayed on a display device (not shown) of the HEMS 70 or a display device (not shown) of the vehicle 50, and make a request to participate in the DR at the consumer's discretion.

[0047] When the participation of the vehicle 50 in DR is permitted, DR permission information is transmitted from the server 30 to the HEMS 70. The DR permission information includes, for example, the DR classification (lower DR / upper DR), the time period (date and time) for executing DR, the requested amount of power, etc. This information enables the consumer to connect the connector 45 of the charge / discharge cable 44 to the inlet 120 of the vehicle 50 on the target date and time.

[0048] When it is time to execute DR, the server 30 transmits DR information to the HEMS 70 to execute DR. The DR information to execute DR includes, for example, the DR category (lower DR / upper DR), the time to start DR, the number of frames for executing DR, and the required power in each frame. In this embodiment, DR is executed in frames, with each frame being 30 minutes. In this embodiment, in the case of higher DR, the DR information transmitted is power consumption in frames (30 minutes) to charge the battery 100 of the vehicle 50. In the case of lower DR, the DR information transmitted is discharge power in frames to discharge the battery 100 of the vehicle 50.

[0049] When the HEMS 70 receives the DR information, it transmits a DR command to the EVSE 40 based on the DR information. For example, if the DR information is a downward DR and the required power is A (kW), when the time to execute the DR arrives, the HEMS 70 transmits a DR command to the EVSE 40 to discharge A (kW) of power from the battery 100 and perform reverse power flow. Note that this "DR command" corresponds to a "command based on DR information" in this disclosure.

[0050] In this embodiment, the DR command from the HEMS 70 to the EVSE 40 is performed in units of frames (in units of 30 minutes in this embodiment). For example, if the DR information received from the server 30 is a downward DR for discharging A (kW) for four frames from 13:00 to 15:00, when the DR execution timing (start timing) reaches 13:00, a DR command is transmitted from the HEMS 70 to the EVSE 40 to discharge A (kW) in order to execute the downward DR for the first frame (until 13:30). When the EVSE 40 receives the DR command, it controls the power supply circuit 43 and the charge / discharge circuit 130 to discharge A (kW) of power from the battery 100. Then, the timing at which the first frame ends (13:30) is the DR execution timing for the second frame (until 14:00), so the DR command is transmitted from the HEMS 70 to the EVSE 40 to discharge A (kW), and the EVSE 40 continues discharging from the battery 100 based on the updated DR command. At 3:00 p.m. when the fourth frame ends, it is time for the downward DR to end, so the HEMS 70 sends a DR command to the EVSE 40 to stop discharging from the battery 100, and the EVSE 40 stops discharging from the battery 100 based on the updated DR command.

[0051] Since the HEMS 70 and the EVSE 40 are connected by a LAN, depending on the communication environment, the communication may become unstable. In addition, the HEMS 70 may temporarily not operate normally due to a bug in the HEMS 70. When the LAN communication becomes unstable or when the HEMS 70 temporarily does not operate normally, the EVSE 40 cannot be controlled based on the DR information (DR command). For this reason, when there is a request for downward DR from the server 30 and the vehicle 50 (battery 100) is discharged and reverse power flow is performed, for example, when the LAN communication becomes unstable and the EVSE 40 cannot receive a DR command from the HEMS 70 to stop discharging the battery 100, the discharge of the battery 100 is not stopped, and the battery 100 may be over-discharged.

[0052] In this embodiment, when the EVSE 40 cannot obtain a DR command from the HEMS 70 while discharging the vehicle 50 (battery 100) and performing reverse power flow, the EVSE 40 stops discharging the battery 100 (stops the reverse power flow) to prevent the battery 100 from becoming over-discharged.

[0053] FIG. 3 is a diagram showing functional blocks configured in the control unit 41 of the EVSE 40. The control unit 41 corresponds to an example of the "control device" of the present disclosure. In FIG. 3, the communication interruption detection unit 411 detects that a command based on the DR information (DR command) cannot be acquired from the HEMS 70 that acquires the DR information from the server 30. For example, as described above, when the HEMS 70 receives DR information of a lowering DR for discharging A (kW) from the server 30 in four frames from 13:00 to 15:00, a DR command is transmitted from the HEMS 70 to the EVSE 40 to discharge A (kW) in order to execute the lowering DR of the first frame at 13:00, which is the execution timing (start timing) of the DR. Then, at the end of the first frame (13:30), a DR command is transmitted from the HEMS 70 to the EVSE 40 to discharge A (kW) in order to execute the lowering DR of the second frame (until 14:00). For example, when communication is interrupted between the HEMS 70 and the EVSE 40 and the communication unit 42 does not receive a DR command from the HEMS 70 (cannot acquire the DR command) even when the timing for the first frame of DR to end (13:30 in this example) is reached, the communication interruption detection unit 411 detects that the DR command cannot be acquired. Similarly, when the communication unit 42 does not receive a DR command from the HEMS 70 (cannot acquire the DR command) even when the timing for the second frame or later of DR to end is reached, the communication interruption detection unit 411 detects that the DR command cannot be acquired.

[0054] When the communication interruption detection unit 411 detects that the DR command cannot be obtained from the HEMS 70, if the vehicle 50 (battery 100) is discharging and performing reverse power flow, the processing unit 412 controls the power supply circuit 43 to stop discharging the battery 100 and charge the battery 100 using power from the power grid PG. At this time, the processing unit 412 transmits a charge / discharge command to the vehicle 50 (ECU 110) so that the charge / discharge circuit 130 switches from a discharging operation to a charging operation. At this time, the processing unit 412 may control the power supply circuit 43 and the charge / discharge circuit 130 so that the battery 100 is fully charged.

[0055] The communication abnormality detection unit 413 detects a communication abnormality between the vehicle 50 (communication device 140) and the EVSE 40 (communication unit 42). For example, when the connector 45 is connected to the inlet 120 but high-level communication is not established by CPLT or communication is not established by CAN, the communication abnormality detection unit 413 may detect a communication abnormality between the vehicle 50 (communication device 140) and the EVSE 40 (communication unit 42).

[0056] When the communication abnormality detection unit 413 detects a communication abnormality between the vehicle 50 (communication device 140) and the EVSE 40 (communication unit 42), if the EVSE 40 is charging the battery 100 using the power of the power grid PG, the processing unit 412 controls the power supply circuit 43 to stop charging the battery 100. This stops discharging the battery 100, and controls the power supply circuit 43 to stop charging the battery 100 if the battery 100 is being charged using the power of the power grid PG.

[0057] 4 is a flowchart showing an example of a process of communication abnormality control executed by the control unit 41 of the EVSE 40. This flowchart is repeatedly processed at predetermined intervals while the EVSE 40 is in operation. First, in step (hereinafter, step is abbreviated as "S") 10, the EVSE 40 judges whether it is time to obtain a DR command (a command based on DR information) from the HEMS 70. For example, based on DR permission information transmitted from the server 30 to the HEMS 70, the DR execution timing of each frame is stored in advance, and it is judged whether it is time to transmit a DR command from the HEMS 70. If it is time to transmit a DR command from the HEMS 70, it is the time to obtain the DR command, and a positive judgment is made and the process proceeds to S11. If it is not time to transmit a DR command from the HEMS 70, a negative judgment is made and the process proceeds to S14.

[0058] In S11, the EVSE 40 determines whether or not a DR command (a command based on DR information) can be acquired from the HEMS 70. For example, when communication between the communication device 73 and the communication unit 42 is interrupted due to deterioration of the LAN communication environment or the like, and the communication unit 42 cannot receive the DR command from the communication device 73 (when the DR command cannot be acquired) at the timing when the DR command is transmitted from the HEMS 70, it is determined that the DR command cannot be acquired. When the DR command cannot be acquired, a positive determination is made and the process proceeds to S12. When the DR command can be acquired, a negative determination is made and the process proceeds to S16, where charging and discharging are performed according to the DR command, and the process proceeds to S14. Note that when the DR command is to stop charging and discharging, charging and discharging from the battery 100 is stopped in S16.

[0059] In S12, it is determined whether the battery 100 of the vehicle 50 is discharging and performing reverse power flow. If the battery 100 is discharging and performing reverse power flow, a positive determination is made and the process proceeds to S13. If the battery 100 is not discharging and not performing reverse power flow, the process proceeds to S14.

[0060] In S13, discharging from the battery 100 is stopped, reverse power flow is stopped, and the power supply circuit 43 is controlled so that the battery 100 is fully charged, and a full charge command is sent to the vehicle 50. The vehicle 50 (ECU 110) receives the full charge command and controls the charge / discharge circuit 130 so that the battery 100 is fully charged.

[0061] In the next S14, it is determined whether or not there is an abnormality in the communication between the vehicle 50 (communication device 140) and the EVSE 40 (communication unit 42). For example, if high-level communication by CPLT is not established even when the connector 45 is connected to the inlet 120, or if communication by CAN is not established, it is determined that there is an abnormality in the communication between the vehicle 50 and the EVSE 40, a positive determination is made, and the process proceeds to S15. If there is no abnormality in the communication between the vehicle 50 and the EVSE 40, a negative determination is made, and the current routine is terminated.

[0062] In S15, the power supply circuit 43 is controlled so as to stop charging and discharging the battery 100, and the current routine is terminated.

[0063] In addition, if communication between the communication device 73 and the communication unit 42 is interrupted due to deterioration of the communication environment of the LAN, etc., and it is determined in S11 that the EVSE 40 cannot obtain the DR command, when communication with the LAN is restored, a negative determination is made in S11, and charging / discharging is performed according to the DR command in S16.

[0064] In this embodiment, the HEMS 70 (gateway device) acquires the DR information transmitted from the server 30. Then, when the communication state between the communication device 73 and the communication unit 42 (first communication device) that communicate between the HEMS 70 and the EVSE 40 becomes unstable, for example, communication interruption occurs, and the EVSE 40 cannot acquire a command based on the DR information (DR command) from the HEMS 70, if reverse power flow is being performed from the vehicle 50 (battery 100) via the EVSE 40, discharging from the battery 100 is stopped, and the reverse power flow is stopped. Therefore, when the EVSE 40 cannot acquire the DR command, discharging from the battery 100 is stopped, and it is possible to prevent the battery 100 from continuing to discharge and becoming over-discharged. In addition, when communication between the server 30 and the HEMS 70 becomes unstable and the HEMS 70 cannot obtain DR information from the server 30, causing the EVSE 40 to be unable to obtain a DR command, discharging from the battery 100 is also stopped, thereby preventing the battery 100 from entering an over-discharge state.

[0065] In this embodiment, when the EVSE 40 cannot obtain a DR command and is performing reverse power flow, the discharge from the battery 100 is stopped and the battery 100 is controlled to be fully charged. When the EVSE 40 cannot obtain a DR command and the vehicle 50 (battery 100) cannot be used as a DER, the battery 100 is charged, so that power can be stored for the next time the vehicle 50 travels. In this case, the charge amount of the battery 100 does not need to be fully charged. For example, a charging history may be stored, and a charging command may be issued to charge the battery 100 to the same charge amount as when charging was performed on the same day of the week in the past. Note that by issuing a charging command to fully charge the battery 100, the logic of the charging command can be simplified.

[0066] In this embodiment, when an abnormality occurs in communication between the communication device 140 and the communication unit 42 (second communication device) that communicates between the vehicle 50 and the EVSE 40, charging and discharging of the battery 100 are stopped. Therefore, when an abnormality occurs in communication between the vehicle 50 and the EVSE 40 during charging after the reverse power flow is stopped (discharge of the battery 100 is stopped), the transfer of power by the EVSE 40 is stopped. As a result, when an abnormality occurs in communication such as when communication between the vehicle 50 and the EVSE 40 is cut off and charging of the battery 100 cannot be performed satisfactorily, the transfer of power by the EVSE 40 is stopped, so that the battery 100 can be protected from overcharging, etc.

[0067] In a configuration in which a plurality of EVSEs are controlled by the HEMS 70, communication between the HEMS 70 and the plurality of EVSEs may be interrupted. If communication interruption occurs while each EVSE is performing reverse power flow, the reverse power flow (discharging from the battery) is stopped in each EVSE. Then, charging is performed so that the vehicles connected to each EVSE are fully charged. In this case, when the charging power becomes excessive (for example, when it exceeds the contracted capacity), the charging operation of the EVSE to which an electric vehicle (BEV) is connected is prioritized over the charging operation of the EVSE to which a plug-in hybrid vehicle (PHEV) is connected. As a result, charging of electric vehicles (BEVs) without internal combustion engines is prioritized.

[0068] In the above embodiment, the control unit 41 of the EVSE 40 is configured with the functional blocks shown in Fig. 3. However, some or all of the functional blocks shown in Fig. 3 may be configured in the ECU 110 of the vehicle 50. Similarly, some or all of the processing of the flowchart shown in Fig. 4 may be executed by the ECU 110 of the vehicle 50. In this case, the control unit 41 and the ECU 110 correspond to an example of a "control device" in the present disclosure.

[0069] In the above embodiment, the communication interruption detection unit 411 (see FIG. 3) and S10 and S11 (see FIG. 4) detect (determine) whether or not the DR command can be acquired at the timing of receiving the DR command. However, a monitor function that constantly monitors the communication state between the HEMS 70 (communication device 73) and the EVSE 40 (communication unit 42) may be provided, and the monitor function may detect (determine) that the EVSE 40 cannot acquire the DR command when communication between the HEMS 70 and the EVSE 40 is interrupted.

[0070] 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 by the description of the embodiments described above, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0071] 1 Power system, 10 Server, 11 Power plant, 12 Power transmission and distribution equipment, 13 Smart meter, 20 Server, 30 Server, 31 Control device, 32 Storage device, 33 Communication device, 40 EVSE, 41 Control unit, 411 Communication interruption detection unit, 412 Processing unit, 413 Communication abnormality detection unit, 42 Communication unit, 43 Power circuit, 44 Charging and discharging cable, 45 Connector, 50 Vehicle, 60 EMS network, 70 HEMS, 71 Control device, 72 Storage device, 73 Communication device, 100 Battery, 110 ECU, 120 Inlet, 130 Charging and discharging circuit, 140 Communication device, E1 Power company, E2 Upper aggregator, E3 Lower aggregator, PG Power system.

Claims

1. A power system including: a vehicle having a power storage device; a power supply device that supplies and receives power between a power grid and the vehicle; a gateway device that acquires DR information transmitted from a server; a first communication device that communicates between the power supply device and the gateway device; and a control device, When reverse power flow is being performed from the vehicle via the power supply device, if the power supply device cannot obtain a command based on the DR information, the control device stops discharging from the power storage device and stops the reverse power flow.

2. The power system according to claim 1 , wherein the control device executes control to charge the power storage device from the power grid via the power supply device, in addition to stopping the reverse power flow.

3. A second communication device that performs communication between the vehicle and the power supply device, The power system according to claim 2 , wherein the control device stops the supply of power by the power feeding device when an abnormality occurs in communication by the second communication device while the power storage device is being charged.

4. A control device that controls a power supply device that transfers power between a vehicle equipped with a power storage device and a power grid, The control device includes: a communication interruption detection unit that detects that the power supply device cannot acquire a command based on the DR information from a gateway device that acquires the DR information from a server; a processing unit that stops discharging from the storage device and stops the reverse power flow when the communication interruption detection unit detects that the DR information cannot be obtained while reverse power flow is being performed from the vehicle via the power supply device.

5. The control device according to claim 4 , wherein the processing unit executes a process of charging the power storage device from the power grid via the power feeding device, in addition to stopping the reverse power flow.

6. The control device further includes a communication abnormality detection unit that detects an abnormality in communication between the vehicle and the power supply device, 6. The control device according to claim 5, wherein when the charging of the power storage device is being performed, the processing unit stops the transmission and reception of power by the power supply device when the communication abnormality detection unit detects an abnormality in communication between the vehicle and the power supply device.

7. A control method for a power system including a vehicle having a power storage device, a power supply device that supplies and receives power between a power grid and the vehicle, a gateway device that acquires DR information transmitted from a server, and a communication device that communicates between the power supply device and the gateway device, detecting that the power supply device cannot acquire the DR information while performing reverse power flow from the vehicle via the power supply device; The control method for a power system further comprises: stopping discharge from the power storage device and stopping the reverse power flow when the power supply device detects that the DR information cannot be acquired.

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