Power management system

Abstract

To appropriately handle information acquired through different communication paths.SOLUTION: A management server executes processing including a step (S300) of determining whether or not to acquire second data from an EVSE, a step (S302) of determining whether or not to acquire first data from a DCM when it is determined to acquire the second data from the EVSE (YES at S300), a step (S304) of calculating an offset amount when it is determined to acquire the first data from the DCM (YES at S302), a step (S306) of executing synchronization processing, and a step (S308) of executing power control.SELECTED DRAWING: Figure 5

Description

Technical Field

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

Background Art

[0002] A power management system for performing energy management in a power grid is known. In this power grid, for example, a vehicle equipped with a power storage device may be connected via a building. In order to control the power of the power storage device mounted on the vehicle, communication may be performed between the server and the vehicle according to various communication standards.

[0003] Japanese Patent Application Laid-Open No. 2022-184741 (Patent Document 1) discloses, for example, a technique for coping with a case of controlling a device that performs communication in a format according to a plurality of communication standards, such as converting a communication format.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Between the server and the vehicle as described above, for example, communication may be performed by wireless communication, and in addition, when the power grid and the vehicle are connected by a cable or the like, communication may be performed by wired communication. It is required to appropriately handle the information received when communication is performed through a plurality of communication paths in this way.

[0006] The present disclosure has been made to solve the above-described problems, and an object thereof is to provide a power management system that appropriately handles information acquired through different communication paths.

Means for Solving the Problems

[0007] A power management system relating to a certain aspect of this disclosure comprises a vehicle equipped with an energy storage device, transmission equipment for transmitting power between the power grid and the energy storage device, and a server for communicating with the vehicle. The server includes a communication device that communicates via a first communication path for communication between the vehicle and the server, and a second communication path for communication between the transmission equipment and the server, and a control device that processes data received using the communication device. The control device performs a synchronization process to synchronize the first data and the second data using the difference between a first time when the transmission equipment and the vehicle are connected and the first data containing information about the energy storage device is received via the first communication path, and a second time when the transmission equipment and the vehicle are connected and the second data containing the same information is received via the second communication path.

[0008] In this way, the difference between the first and second time points corresponds to the difference in communication delay, and by using this difference, the first and second data can be synchronized. As a result, control using the first and second data can be performed with high precision. Therefore, information acquired through different communication paths can be handled appropriately.

[0009] In one embodiment, the control device synchronizes the time information in the first data with the time information in the second data using the difference.

[0010] In this way, by synchronizing with the time information in the second data, which has a smaller communication delay than the first data, control using the first and second data can be performed with greater precision.

[0011] In one further embodiment, the control device uses synchronized first and second data to perform power control between the vehicle and the power grid.

[0012] In this way, power control between the vehicle and the power grid can be performed with high precision using the first and second data sets. [Effects of the Invention]

[0013] According to this disclosure, it is possible to provide a power management system that appropriately handles information acquired through different communication paths. [Brief explanation of the drawing]

[0014] [Figure 1] This figure shows an example of the configuration of the power management system according to this embodiment. [Figure 2] This figure shows an example of the communication configuration of the power management system according to this embodiment. [Figure 3] This flowchart shows an example of a process performed in a vehicle. [Figure 4] This flowchart shows an example of the processes performed by EVSE. [Figure 5] This flowchart shows an example of the processes performed on the management server. [Figure 6] This is a diagram illustrating the operation of a power management system. [Modes for carrying out the invention]

[0015] The embodiments of this disclosure will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated.

[0016] Figure 1 shows an example of the configuration of the power management system 1 according to this embodiment. As shown in Figure 1, the power management system 1 comprises a vehicle 10, a power system 40, a building 50, a management server 100, and a DCM (Data Communication Module) server 300.

[0017] The building 50 includes a smart meter 54, a distribution board 56, other loads 58, an indoor controller 60, and an EVSE (Electric Vehicle Supply Equipment) 70.

[0018] The smart meter 54 detects the amount of electric power transmitted between the power grid 40 and the building 50 (more specifically, the distribution board 56). The smart meter 54, for example, detects the amount of electric power supplied from the power grid 40 to the building 50. Further, the smart meter 54, for example, detects the amount of electric power supplied from the building 50 to the power grid 40. The smart meter 54 transmits information indicating the detected amount of electric power to the indoor controller 60.

[0019] The distribution board 56 enables the supply of the voltage of the electric power supplied from the power grid 40 to various electrical devices including the EVSE 70 and other loads 58. The distribution board 56 is provided with a cutoff circuit capable of cutting off the supply of electric power to various electrical devices such as breakers. The other loads 58 are provided, for example, inside the building 50 and include various electrical devices (for example, home appliances) other than the EVSE 70.

[0020] The indoor controller 60 is a control device for managing the electric power supplied from the power grid 40 to various electrical devices in the building 50 via the distribution board 56 and the electric power supplied from any power source in the building 50 to the power grid 40 via the distribution board 56. The indoor controller 60 can acquire information from the smart meter 54 and various electrical devices connected as control targets (for example, the EVSE 70 described later, etc.) and is configured to be able to transmit various control commands (for example, an execution command for charging control, etc.) to various electrical devices.

[0021] The EVSE 70 is a transmission facility capable of electric power transmission, configured to be connectable to the vehicle 10 using a connector and a cable. The EVSE 70 supplies the electric power supplied from the distribution board 56 to the vehicle 10 or outputs the electric power supplied from the vehicle 10 to the distribution board 56 in accordance with a control signal from the indoor controller 60. The EVSE 70 may be configured to supply DC power to the power storage device 11 mounted on the vehicle 10, or alternatively, may be configured to supply AC power to a charging device mounted on the vehicle 10, and the AC power is converted into DC power in the charging device and supplied to the power storage device 11.

[0022] Vehicle 10 is an electric vehicle having a power storage device 11 composed of a rechargeable DC power supply, a drive unit (not shown) composed of an electric motor or the like, and a communication device 16 including a DCM. The power storage device 11 may be a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery with a liquid or solid electrolyte, or it may be a capacitor or the like. Vehicle 10 is configured to be able to charge the power storage device 11 using power supplied from EVSE 70. Vehicle 10 is also configured to be able to supply power from the power storage device 11 to EVSE 70. Furthermore, vehicle 10 is configured to be able to communicate (for example, wirelessly) with DCM server 300 using the communication device 16 (specifically, DCM). In addition, when the connector of EVSE 70 is connected to the inlet (not shown) of vehicle 10, vehicle 10 is configured to be able to communicate (for example, wired communication) with EVSE 70 via the connector and cable using the communication device 16. In Figure 1, vehicle 10 is shown as a representative example, but multiple vehicles other than vehicle 10 may be connected to EVSEs other than EVSE 70.

[0023] The management server 100 receives power supply and demand requests from the power company 150 and manages the power supply and demand in the power grid formed in a predetermined area including the building 50. For example, if the power company 150 requests an increase in power supply, the management server 100 sends a control command to the control targets within the power grid, including the building 50, that are capable of receiving power, to supply power to the power system 40. The control targets within the power grid can satisfy the power company 150's request by increasing the power supplied to the power system 40 as a result of the control command.

[0024] The DCM server 300 is configured to communicate with multiple vehicles (including vehicle 10) equipped with DCMs. For example, the DCM server 300 receives information about the energy storage devices installed in the multiple vehicles equipped with DCMs, or transmits update information such as various control programs to the multiple vehicles equipped with DCMs. The information about the energy storage devices received by the DCM server 300 includes information about the State of Charge (SOC) of the energy storage device, information about the amount of energy that can be charged, information about the amount of energy that can be discharged, etc.

[0025] The vehicle 10, the indoor controller 60, the EVSE 70, the management server 100, and the DCM server 300 are configured to exchange various information via communication.

[0026] Figure 2 shows an example of the communication configuration of the power management system 1 according to this embodiment. As shown in Figure 2, the vehicle 10 includes an ECU (Electronic Control Unit) 12, a storage device 14, and a communication device 16. The ECU 12 has a CPU (Central Control Unit) (not shown) and memory (ROM (Read Only Memory) and RAM (Random Access Memory), etc.), and performs a power supply process that supplies power from the energy storage device 11 to the EVSE 70 or a charging process that charges the energy storage device 11 using power from the EVSE 70, based on various information stored in the memory and various information obtained through communication. Various information includes charging commands and discharge commands from the EVSE 70. The storage device 14 stores various information received using the communication device 16 and predetermined information. The communication device 16 includes a communication unit (not shown) that can communicate wirelessly with the DCM server 300 via a communication network (e.g., a mobile phone line) and the EVSE 70 via wired communication (e.g., PLC (Power Line Communication) communication or CAN (Controller Area Network) communication).

[0027] The indoor controller 60 has a CPU and memory (not shown) and executes processes related to the supply and demand management of power within the building 50 based on various information stored in the memory and various information obtained through communication with the EVSE 70 and the management server 100. The processes related to the supply and demand management of power within the building 50 include, for example, the process of sending a command to execute a charging process (charging command) to the EVSE 70 and the process of sending a command to execute a discharging process (discharging command). In response to a request from the management server 100, the indoor controller 60 transmits information about the energy storage device 11 installed in the vehicle 10 which is subject to power management control by the management server 100 in the power grid to the management server 100. Alternatively, if the indoor controller 60 receives information about the energy storage device 11 from the vehicle 10, it may transmit such information to the management server 100 regardless of whether a request has been made from the management server 100.

[0028] The EVSE 70 includes a control device 72, a storage device 74, and a communication device 76. The control device 72 has a CPU and memory (not shown) and transmits charging commands to the vehicle 10 or discharging commands to the vehicle 10 based on various information stored in the memory and various information obtained through communication. The storage device 74 stores various information received using the communication device 76 and predetermined information. The communication device 76 is configured to communicate with the indoor controller 60 or with the vehicle 10 via a communication network by wireless or wired means.

[0029] The management server 100 includes a control device 102, a storage device 104, and a communication device 106. The control device 102 has a CPU and memory (not shown) and executes processing related to supply and demand management within the power grid based on various information stored in the memory and various information obtained through communication. Processing related to supply and demand management within the power grid includes, for example, the process of sending a charging command to the indoor controller 60 and the process of sending a discharge command. The management server 100 also obtains information for implementing supply and demand management (for example, information related to the energy storage device 11 installed in the vehicle 10) from the indoor controller 60 and the DCM server 300.

[0030] The storage device 104 stores various information received using the communication device 106, as well as predetermined information. For example, the storage device 104 stores information for identifying vehicles that are subject to control in supply and demand management within the power grid (for example, vehicle number and chassis number). This information is used by the management server 100 to obtain information about vehicle 10 from the DCM server 300.

[0031] The communication device 106 is configured to communicate wirelessly or via wired connection with the DCM server 300 or with the indoor controller 60 via a communication network not shown (for example, the Internet or a dedicated line).

[0032] The DCM server 300 has a CPU and memory (not shown), and performs processing to exchange information about energy storage devices with each of the multiple vehicles based on various information stored in memory and various information obtained through communication with multiple vehicles and the management server 100. The DCM server 300 transmits to the management server 100 information about energy storage devices 11 installed in vehicles 10 that are subject to power management control by the management server 100 in the power grid, in response to a request from the management server 100. Alternatively, if the DCM server 300 receives information about energy storage devices 11 from a vehicle 10, it may transmit that information to the management server 100 regardless of whether a request has been made from the management server 100.

[0033] In the power management system 1 having the communication configuration described above, communication-enabled devices communicate with each other according to various communication standards.

[0034] The management server 100 obtains information about energy storage devices (for example, information such as SOC (State of Charge)) from multiple vehicles, including vehicle 10, in order to estimate the amount of charge and discharge possible for multiple vehicles in the power grid.

[0035] Information about the energy storage device is transmitted via at least one of two communication paths: a first communication path (dotted arrow in Figure 1) that goes to the management server 100 via the DCM server 300 without going through the EVSE 70, and a second communication path (solid arrow in Figure 1) that goes to the management server 100 via the EVSE 70 and the indoor controller 60.

[0036] For example, if the vehicle 10's ECU 12 is not connected to the EVSE 70, it transmits information about the energy storage device 11 to the management server 100 via the first communication path. On the other hand, if the vehicle 10's ECU 12 is connected to the EVSE 70, it transmits information about the energy storage device 11 to the management server 100 via both the first and second communication paths.

[0037] When data containing the same information is transmitted via both paths, delays may occur depending on the reliability of each communication path, resulting in the data being received at different times. If the path between the communication device 16 and the DCM server 300 includes a wireless communication path such as a mobile phone line, delays may occur in communication from the communication device 16 to the DCM server 300 if radio wave conditions worsen than normal when the vehicle 10 is traveling or stopped in a tunnel or underground. In this case, it is necessary to handle the received data appropriately.

[0038] Therefore, in this embodiment, the management server 100 operates as follows. Specifically, the management server 100 performs a synchronization process to synchronize the first data and the second data using the difference between a first time when the EVSE 70 and the vehicle 10 are connected and the first data containing information about the energy storage device 11 is received via a first communication path, and a second time when the EVSE 70 and the vehicle 10 are connected and the second data containing the same information is received via a second communication path.

[0039] Since the difference between the first and second time points corresponds to the difference in communication delay, the first and second data can be synchronized by using this difference. As a result, control using the first and second data can be performed with high precision. Therefore, information acquired through different communication paths can be handled appropriately.

[0040] The following describes the processes performed by vehicle 10 (specifically its ECU 12), with reference to Figure 3. Figure 3 is a flowchart showing an example of the processes performed by vehicle 10. Note that the series of processes shown in the flowcharts from Figures 3 to 5 are repeatedly executed at predetermined intervals.

[0041] In step 100 (hereinafter referred to as S), the ECU 12 determines whether or not the plug is connected. The ECU 12 may determine that the plug is connected, for example, when the connector of the EVSE 70 is connected to the inlet of the vehicle 10. The ECU 12 may also determine that the connector is connected, for example, when it receives an ON signal from a circuit (not shown) that outputs an ON signal when the connector is connected to the inlet. If it is determined that the plug is connected (YES in S100), the process moves to S102.

[0042] In S102, the ECU 12 uses the communication device 16 to transmit first data to the management server 100 via the DCM server 300, including the transmission time (hereinafter referred to as the first time) and information about the State of Charge (SOC) of the energy storage device 11 (hereinafter referred to as the first battery information). The ECU 12 sets the transmission time at which it transmits the first data to the DCM server 300 as the first time. The ECU 12 sets the first time using the time information measured internally. The process then moves to S104.

[0043] In S104, the ECU 12 uses the communication device 16 to transmit information about the State of Charge (SOC) of the energy storage device 11 (hereinafter referred to as the second battery information) to the EVSE 70. After that, the process is terminated. If it is determined that the plug is not connected (NO in S100), this process is terminated.

[0044] Next, the processes performed by the EVSE 70 (control device 72) will be explained with reference to Figure 4. Figure 4 is a flowchart showing an example of the processes performed by the EVSE 70.

[0045] In S200, the control device 72 determines whether or not the plug is connected. The control device 72 may determine that the plug is connected if, for example, the connector is connected to the inlet of the vehicle 10. The control device 72 may also determine that the connector is connected if, for example, it receives a signal from the vehicle 10 indicating that the connector is connected to the inlet via wired communication through a cable or via wireless communication. If it is determined that the plug is connected (YES in S200), the process moves to S202.

[0046] In S202, the control device 72 determines whether or not to receive second battery information from the vehicle 10. If it is determined that second battery information has been received from the vehicle 10 (YES in S202), the process moves to S204.

[0047] In S204, the control device 72 transmits second data, including the transmission time (hereinafter referred to as the second time) and second battery information, to the management server 100 via the indoor controller 60. The control device 72 sets the transmission time to be transmitted to the indoor controller 60 as the second time. The control device 72 sets the second time using the time information measured internally. After that, the process is terminated. If it is determined that the plug is not connected (NO in S200) or if it is determined that the second battery information is not received from the vehicle 10 (NO in S202), the process is terminated.

[0048] Next, the processes executed by the control device 102 of the management server 100 will be explained with reference to Figure 5. Figure 5 is a flowchart showing an example of the processes executed by the management server 100.

[0049] In S300, the control device 102 determines whether or not it has acquired the second data from any EVSE in the power grid. The control device 102 also stores the time of reception and the received second data in the storage device 104, at least when it first receives the second data. If it is determined that the second data has been acquired from any EVSE in the power grid (YES in S300), the process moves to S302.

[0050] In S302, the control device 102 determines whether or not it has acquired the first data from the DCM server 300. The control device 102 identifies the vehicle 10 connected to the EVSE 70 using the second data, for example, and requests the first data for the identified vehicle 10 from the DCM server 300. The DCM server 300 may send the first data for the vehicle 10 to the management server 100 in response to the request. Alternatively, the control device 102 may extract and acquire the first data for the vehicle 10 from the various data sequentially received from the DCM server 300. The control device 102 stores the time of receipt and the received first data in the storage device 104, at least when it first receives the first data. If it is determined that the first data has been acquired from the DCM server 300 (YES in S302), the process moves to S304.

[0051] In S304, the control device 102 calculates the offset amount. The control device 102 calculates the offset amount as the difference between the reception time of the first data received after the vehicle 10 was plugged in (hereinafter referred to as the first reception time) and the reception time of the second data received after the vehicle 10 was plugged in (hereinafter referred to as the second reception time). The offset amount represents the difference between the delay time from when the first data is transmitted from the vehicle 10 until it is received by the management server 100 via the DCM server 300, and the delay time from when the second data is transmitted from the EVSE 70 until it is received by the management server 100. In this case, the first data is transmitted from the vehicle 10 at the timing when it is determined that the vehicle has been plugged in. The first data is transmitted from the EVSE 70 at approximately the same timing when it is determined that the vehicle has been plugged in. As a result, the difference between the first reception time and the second reception time represents the difference in delay time and is calculated as the offset amount. The process then moves to S306.

[0052] In S306, the control device 102 performs synchronization processing. More specifically, the control device 102 sets the reception time of the first data at the management server 100 to a time obtained by an offset amount, and performs synchronization processing to associate the battery information of the first data corresponding to the reception time before synchronization with the reception time after synchronization. The control device 102 performs synchronization processing on the first data received while the plug is connected. The subsequent processing is moved to S308.

[0053] In S308, the control device 102 performs power control using the synchronized first data and second data. Power control includes power control related to supply and demand management, such as charge and discharge control of the energy storage device 11. If the first data is obtained from the DCM server 300 and contains more detailed information than the second data, the control device 102 uses the first data to supplement the second data, or uses the first and second data to accurately estimate the SOC of the energy storage device 11 and changes in SOC. This enables power supply and demand management within the power grid in accordance with the supply and demand requests from the power company 150. The process then ends. On the other hand, if it is determined that the second data is not to be obtained from EVSE 70 (NO in S300), this process ends. Also, if it is determined that the first data is not to be obtained from the DCM server 300 (NO in S302), the process returns to S302.

[0054] The operation of the power management system 1 according to this embodiment, based on the above configuration and flowchart, will be explained with reference to Figure 6.

[0055] Figure 6 is a diagram illustrating the operation of the power management system 1. The horizontal axis of Figure 6 represents time. The vertical axis of Figure 6 represents the amount of data transmitted from the DCM, the amount of data received from the DCM (1) at the management server, the amount of data received from the EVSE 70 (2) at the management server, and the amount of data transmitted from the EVSE. LN1 in Figure 6 shows the change in the amount of data transmitted from the DCM. LN2 in Figure 6 shows the change in the amount of data transmitted from the EVSE 70. LN3 in Figure 6 shows the change in the amount of data received (1) before synchronization. LN4 in Figure 6 shows the change in the amount of data received (2). LN5 in Figure 6 shows the change in the amount of data received (2) after synchronization. Note that Figure 6 assumes a case where the time measured internally in the vehicle 10, the management server 100, and the EVSE 70 is not synchronized (the time measured differs even when the same plug is connected). Furthermore, Figure 6 assumes a scenario where the device is plugged in at time T(0) and disconnected at time T(1), based on the time measured by the management server 100.

[0056] For example, when a plug connection is made in vehicle 10 (YES in S100), first data including the plug connection transmission time T(2) and first battery information is transmitted to the management server 100 via the DCM server 300, as shown in LN1 in Figure 6 (S102). Furthermore, second battery information is transmitted to EVSE 70 via the connector and cable (S104).

[0057] In EVSE70, once a plug connection is made (YES in S200) and second battery information is received from the vehicle 10 (YES in S202), second data including the plug connection transmission time T(3) and second battery information is transmitted to the management server 100 via the indoor controller 60 (S204), as shown in LN2 of Figure 6.

[0058] In the management server 100, as shown in LN4 and LN5 in Figure 6, the data is received after a certain delay time has elapsed. That is, when the management server 100 receives the second data at the second reception time (YES in S300), it receives the first data that was initially transmitted at the first reception time (YES in S302), and uses the difference between the first reception time and the second reception time as the offset amount (S304).

[0059] Then, a synchronization process is performed (S306), and the reception time associated with the battery information of the first data is set to the time after synchronization by the offset amount. As a result, as shown in LN5 in Figure 6, the reception time of the first data and the reception time of the second data are synchronized. Power control is performed using the synchronized first data and second data (S308). The management server 100 treats the first data with the synchronized reception time and the second data with the corresponding reception time as if they were data from the same time and performs power control.

[0060] As described above, according to the power management system 1 of this embodiment, the difference between the first reception time and the second reception time corresponds to the difference in communication delay, and by using this difference, the first data and the second data can be synchronized. As a result, control using the first data and the second data can be performed with high accuracy. Therefore, a power management system that appropriately handles information acquired through different communication paths can be provided.

[0061] Furthermore, synchronization can be performed even if at least one of the following timestamps differs: the time measured inside the vehicle 10, the time measured inside the management server 100, and the time measured inside the EVSE 70. Therefore, power control using the synchronized first and second data can be performed with high accuracy.

[0062] Furthermore, by synchronizing the first data with the second data having the smaller delay time, power control using the first and second data can be performed with high accuracy. In this embodiment, the case where the first data is synchronized with the second data having the smaller delay time was described as an example, but the second data may be synchronized with the first data having the larger delay time when the difference in delay times is small.

[0063] The following describes variations. In the above-described embodiment, the first data and the second data were described as being synchronized. However, if the delay time of the first data or the delay time of the second data can be determined, the first data and the second data may be synchronized to the time measured internally by the management server 100. In this way, power control using the first data and the second data can be performed with even greater precision.

[0064] Furthermore, in the above-described embodiment, the battery information was explained as including the State of Charge (SOC) of the energy storage device 11 as an example. However, for example, instead of or in addition to the SOC, at least one of the following may be included: the dischargeable capacity, the rechargeable capacity, the current dischargeable energy, and the current rechargeable energy.

[0065] Furthermore, the above-mentioned modifications may be implemented by combining all or part of them as appropriate. The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0066] 1 Power management system, 10 Vehicles, 11 Energy storage devices, 12 ECUs, 14, 74, 104 Memory devices, 16, 76, 106 Communication devices, 40 Power grids, 50 Buildings, 54 Smart meters, 56 Distribution boards, 58 Loads, 60 Indoor controllers, 70 EVSEs, 72, 102 Control devices, 100 Management servers, 150 Power companies, 300 DCM servers.

Claims

1. Vehicles equipped with energy storage devices, A transmission facility that transmits power between the power grid and the energy storage device, The system includes a server that communicates with the aforementioned vehicle, The aforementioned server, A communication device that communicates between the vehicle and the server via a first communication path and between the transmission equipment and the server, The device includes a control device that processes data received using the aforementioned communication device, The control device is A power management system that performs a synchronization process to synchronize the first data and the second data using the difference between a first time when the transmission equipment and the vehicle are connected and the first data including information about the energy storage device is received on the first communication path, and a second time when the transmission equipment and the vehicle are connected and the second data including the same information is received on the second communication path.

2. The power management system according to claim 1, wherein the control device synchronizes the time information in the first data with the time information in the second data using the difference.

3. The power management system according to claim 1 or 2, wherein the control device performs power control between the vehicle and the power grid using the synchronized first data and the second data.

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