Power management system, integrated management system

Abstract

To provide an electric power management system and an integrated electric power management system capable of ensuring interests of both a consumer and an electric power retailer while allowing a reverse power flow from an electric power storage device installed in an electric vehicle or the like.SOLUTION: An electric power management system 1 includes an electric power converter unit 10 that is connected between a grid 2 and an electric power generation device (solar battery) 5 based on renewable energy and that is connectable with a mobile electric power storage device 6, and an external connection management device 20 that stores and manages an amount of electric power received from the grid and an amount of electric power reversed to the grid. The electric power storage device is capable of charging electric power from the electric power generation device, charging electric power from the grid, reversing electric power to the grid, and charging electric power from another charging facility. The external connection management device manages the source of electric power charged in the electric power storage device.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a power management system that manages power from a power storage device mounted on an electric vehicle or the like, and an integrated power management system. [Background technology]

[0002] In Japan, retail electricity sales were liberalized in April 2016, and many new operators have entered the market. Meanwhile, electric vehicles (EVs), plug-in hybrid vehicles (PHVs), and other electric vehicles have become increasingly popular in recent years. Some electricity retailers are offering EV plans with preferential electricity rates to consumers who own electric vehicles.

[0003] In recent years, attempts have been made to build a Virtual Power Plant (VPP) by networking distributed power sources such as solar cells, storage batteries, and household fuel cells. It is expected that in the future, storage batteries installed in electric vehicles will also be used as a balancing force for the power grid (see, for example, Patent Document 1).

[0004] In Japan, a specified measurement system is scheduled to start in April 2022, which will allow the use of special measuring instruments that do not undergo inspection under the Weights and Measurement Act. After the start of the specified measurement system, it will be possible to use power conditioners and electric vehicle charging and discharging equipment that have not undergone inspection under the Weights and Measurement Act as measuring instruments. In addition, in the future, restrictions on reverse power flow from on-board storage batteries to the power grid are expected to be relaxed in order to comply with the principle of simultaneous and equal amounts by aggregators. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2012-75306 A Summary of the Invention [Problem to be solved by the invention]

[0006] Vehicle-mounted batteries can also be charged from chargers outside the home. For example, they can be charged from free charging stations installed in large commercial facilities. Electricity retailers are concerned that their business will be unable to operate if electricity that has been charged into vehicle-mounted batteries outside the home for free or at low cost is reverse-powered from the home.

[0007] The present disclosure has been made in consideration of these circumstances, and its purpose is to provide a power management system and an integrated power management system that can ensure the benefits of both consumers and retail electricity suppliers while allowing reverse power flow from a power storage device mounted on an electric vehicle or the like. [Means for solving the problem]

[0008] In order to solve the above problems, a power management system according to an embodiment of the present disclosure includes a power conversion unit that is connected between a power generation device based on renewable energy and a grid and is capable of connecting a portable power storage device, and a management unit that stores and manages the amount of power received from the grid and the amount of power that is reverse-flowed to the grid. The power storage device is capable of being charged from the power generation device, being charged from the grid, and reverse-flowing to the grid, and is also capable of being charged from another charging facility, and the management unit manages the origin of the power stored in the power storage device. Effect of the Invention

[0009] According to the present disclosure, it is possible to ensure the benefits of both consumers and electricity retailers while permitting reverse power flow from a power storage device mounted on an electric vehicle or the like. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram for explaining a power management system according to a first embodiment. [Diagram 2] FIG. 2 is a diagram illustrating a power supply system of an electric vehicle. [Diagram 3] FIG. 2 is a diagram illustrating an example of the configuration of an external connection management device. [Figure 4] 4(a) and 4(b) are diagrams showing a specific example of the transition of the origin of the electric power stored in the power storage unit of the electric vehicle and the transition of the amount of possible reverse power flow from the power storage unit according to the first embodiment. [Diagram 5] FIG. 11 is a diagram for explaining a power management system according to a second embodiment. [Figure 6] 6(a) and 6(b) are diagrams showing a specific example of the transition of the origin of the electric power stored in the power storage unit of an electric vehicle and the transition of the amount of possible reverse power flow from the power storage unit according to the second embodiment. [Figure 7] FIG. 13 is a diagram for explaining a power management system according to a modification of the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] (Embodiment 1) 1 is a diagram for explaining a power management system 1 according to a first embodiment. The power management system 1 includes a power conversion device 10 and an external connection management device 20. The power conversion device 10 is a power conditioner for a solar power generation system. The power conversion device 10 includes a DC / DC converter 11, an inverter 12, a converter control circuit 13, an inverter control circuit 14, and a control unit 15.

[0012] The solar cell 5 is a power generating device that utilizes the photovoltaic effect to directly convert light energy into DC power. As the solar cell 5, a silicon solar cell, a solar cell made of a material such as a compound semiconductor, a dye-sensitized solar cell, an organic thin-film solar cell, or the like is used. The solar cell 5 is connected to a DC / DC converter 11 of the power conversion device 10, and outputs the generated power to the power conversion device 10. The DC / DC converter 11 is connected between the solar cell 5 and the DC bus Bd, and is a converter capable of adjusting the voltage of the DC power output from the solar cell 5. The DC / DC converter 11 can be configured, for example, by a boost chopper.

[0013] The converter control circuit 13 controls the DC / DC converter 11. As a basic control, the converter control circuit 13 controls the DC / DC converter 11 by MPPT (Maximum Power Point Tracking) so that the output power of the solar cell 5 is maximized. Specifically, the converter control circuit 13 measures the input voltage and input current of the DC / DC converter 11, which are the output voltage and output current of the solar cell 5, to estimate the power generated by the solar cell 5. The converter control circuit 13 generates a command value for making the power generated by the solar cell 5 a maximum power point (optimum operating point) based on the measured output voltage of the solar cell 5 and the estimated power generation. For example, the converter control circuit 13 changes the operating point voltage by a predetermined step width according to a hill-climbing method to search for the maximum power point, and generates a command value to maintain the maximum power point. The DC / DC converter 11 performs switching operation in response to a drive signal based on the generated command value.

[0014] The converter control circuit 13 can also control the step-up ratio of the DC / DC converter 11 so that the voltage of the DC bus Bd is maintained at a target value, or so that the measured value of the power generation of the solar cell 5 is maintained at a target value. This control may be activated when it becomes necessary to suppress the amount of power generation of the solar cell 5.

[0015] The inverter 12 is a bidirectional inverter connected between the DC bus Bd and the distribution board 3. The inverter 12 converts DC power input from the DC bus Bd into AC power, and outputs the converted AC power to the distribution board 3. A commercial power system (hereinafter simply referred to as system 2) is connected to the distribution board 3. A load 4 is connected to the distribution board 3. The load 4 is a general term for loads within the home. The inverter 12 can also convert AC power supplied from the system 2 via the distribution board 3 into DC power, and output the converted DC power to the DC bus Bd.

[0016] A current sensor CT1 is installed on the current path between the distribution board 3 and the system 2. The current sensor CT1 measures the current flowing between the system 2 and the distribution board 3 and outputs the current to the control unit 15. The current flowing from the system 2 to the distribution board 3 is defined as a forward flow current (power purchase), and the current flowing from the distribution board 3 to the system 2 is defined as a reverse flow current (power sale).

[0017] The inverter control circuit 14 controls the inverter 12. As a basic control, the inverter control circuit 14 controls the inverter 12 so that the voltage of the DC bus Bd maintains a target value. Specifically, the inverter control circuit 14 detects the voltage of the DC bus Bd and generates a command value for matching the detected bus voltage with the target value. When the voltage of the DC bus Bd is higher than the target value, the inverter control circuit 14 generates a command value for increasing the duty ratio of the inverter 12, and when the voltage of the DC bus Bd is lower than the target value, the inverter control circuit 14 generates a command value for decreasing the duty ratio of the inverter 12. The inverter 12 performs switching operation in response to a drive signal based on the generated command value.

[0018] The control unit 15 performs overall control of the power conversion device 10. The control unit 15 can be realized by a combination of hardware resources and software resources, or by hardware resources alone. Analog elements, microcontrollers, DSPs, ROMs, RAMs, ASICs, FPGAs, and other LSIs can be used as hardware resources. Programs such as firmware can be used as software resources.

[0019] The control unit 15 can obtain the amount of power generated by the solar cell 5 from the converter control circuit 13. The control unit 15 can also calculate the amount of power purchased and the amount of power sold based on the current value measured by the current sensor CT1. The control unit 15 can transmit and receive various information to and from an external connection management device (also called a remote control setting device) 20.

[0020] The external connection management device 20 and the power conversion device 10 may be connected by wire (e.g., a cable conforming to the RS-485 standard) or wirelessly (e.g., Wi-Fi (registered trademark), low-power wireless). The external connection management device 20 is connected to a router device 7. The external connection management device 20 and the router device 7 are connected by wire (e.g., a LAN cable) or wirelessly (e.g., Wi-Fi). The external connection management device 20 functions as an operation terminal for operating the power conversion device 10 and as a gateway for connecting to an external network 8. A detailed configuration of the external connection management device 20 will be described later.

[0021] The vehicle power conversion device 30 is a device (also referred to as a V2H (Vehicle to Home) converter) for linking the power conversion device 10 and the electric vehicle 6. The vehicle power conversion device 30 includes a DC / DC converter 31, a converter control circuit 32, and a control unit 33. One end of the DC / DC converter 31 is connected to the electric vehicle 6 via a charging cable, and the other end of the DC / DC converter 31 is connected to the DC bus Bd of the power conversion device 10. The DC / DC converter 31 is a bidirectional DC / DC converter for charging and discharging a power storage unit 61 (see FIG. 3) of the electric vehicle 6.

[0022] The control unit 33 comprehensively controls the entire vehicle power conversion device 30. The control unit 33 can be realized by a combination of hardware resources and software resources, or by hardware resources alone. The control unit 33 is connected to the control unit 15 of the power conversion device 10 by wire or wirelessly.

[0023] Converter control circuit 32 controls DC / DC converter 31. As basic control, converter control circuit 32 controls charging and discharging of DC / DC converter 31 based on command values ​​set by control unit 33. As charge and discharge control, for example, constant current (CC) control and constant voltage (CV) control are possible. Control unit 33 can obtain the amount of charge to and discharge from power storage unit 61 of electric vehicle 6 from converter control circuit 32.

[0024] 2 is a diagram illustrating a schematic power supply system of electric vehicle 6. Electric vehicle 6 includes a power storage unit 61, an inverter 62, a motor 63, a DC / DC converter 64, a management unit 65, a contactor relay RY1, and a charging relay RY2.

[0025] The power storage unit 61 is a chargeable and dischargeable power storage unit including a plurality of cells. The cells may be lithium ion battery cells, nickel metal hydride battery cells, electric double layer capacitor cells, lithium ion capacitor cells, etc. The power storage unit 61 is connected to an inverter 62 for driving a motor 63 for traveling via a contactor relay RY1. The motor 63 shown in FIG. 2 is a three-phase AC motor.

[0026] During power running, inverter 62 converts DC power supplied from power storage unit 61 into AC power and supplies it to motor 63. Motor 63 rotates according to the AC power supplied from inverter 62. During regeneration, motor 63 converts rotational energy generated by deceleration into AC power and supplies it to inverter 62. Inverter 62 converts AC power supplied from motor 63 into DC power to charge power storage unit 61.

[0027] The management unit 65 comprehensively controls the entire power supply system mounted on the electric vehicle 6, including the power storage unit 61. The management unit 65 can be realized by a combination of hardware and software resources, or by hardware resources alone. The management unit 65 estimates the SOC (State Of Charge) and SOH (State Of Health) of each cell and the entire power storage unit 61, based on the voltage, current, and temperature of each cell received from the power storage unit 61. If an overvoltage, undervoltage, overcurrent, or abnormal temperature occurs in at least one of the cells in the power storage unit 61 while the inverter 62 is running, the management unit 65 turns off the contact relay RY1 to protect that cell.

[0028] The electric vehicle 6 can be connected to the vehicle power conversion device 30 via a charging cable C1. The power storage unit 61 is connected to the charging cable C1 via a charging relay RY2 and a DC / DC converter 64. The charging cable C1 includes a communication line in addition to a power line. The management unit 65 can communicate with the control unit 33 in the vehicle power conversion device 30 via the communication line in the charging cable C1.

[0029] The power storage unit 61 can be charged from the system 2 via the distribution board 3, the power conversion device 10, the vehicle power conversion device 30, the charging cable C1, and the DC / DC converter 64. At this time, quick charging is also possible. For example, CHAdeMO (registered trademark), ChaoJi, GB / T, Combo (Combined Charging System), etc. can be used as the quick charging standard. In CHAdeMO2.0, the maximum output (specification) is specified as 1000V×400A=400kW. In CHAdeMO3.0, the maximum output (specification) is specified as 1500V×600A=900kW. In CHAdeMO, CAN (Controller Area Network) is adopted as the communication method. It is also possible to use PLC (Power Line Communication) without using a communication line.

[0030] During quick charging, the DC / DC converter 31 in the vehicle power conversion device 30 boosts the voltage of the DC power supplied from the DC bus Bd to a commanded voltage and outputs it. The DC / DC converter 64 in the electric vehicle 6 steps down the voltage of the DC power supplied from the vehicle power conversion device 30 via the charging cable C1 to a voltage for charging the power storage unit 61 and supplies it to the power storage unit 61.

[0031] In order to reduce the load on the power storage unit 61, it is also possible to charge the power storage unit 61 at a low speed from the grid 2. In addition, the power generated by the solar cell 5 can also be charged into the power storage unit 61 via the power conversion device 10, the vehicle power conversion device 30, the charging cable C1, and the DC / DC converter 64.

[0032] It is also possible to discharge the power from the power storage unit 61 into the house. The DC / DC converter 64 in the electric vehicle 6 converts the DC power supplied from the power storage unit 61 into DC power having a voltage higher than the voltage of the DC bus Bd in the power conversion device 10 (for example, about 320 V), and outputs the converted DC power. To reduce conversion loss in the inverter 12, it is desirable to convert the voltage to a voltage as close as possible to the voltage of the DC bus Bd. This voltage conversion may be performed by the DC / DC converter 31 in the vehicle power conversion device 30.

[0033] 3 is a diagram showing an example of the configuration of the external connection management device 20. The external connection management device 20 includes a processing unit 21, a storage unit 22, an operation unit 23, and a display unit 24. The processing unit 21 includes a metering data acquisition unit 211, an electric vehicle information acquisition unit 212, an electric vehicle charge / discharge amount management unit 213, and a data transmission unit 214. The processing unit 21 can be realized by a combination of hardware resources and software resources, or by hardware resources alone.

[0034] The storage unit 22 includes a metered data storage unit 221, an electric power derived data storage unit 222, and an electric vehicle information storage unit 223. The storage unit 22 includes a non-volatile recording medium such as an SSD (Solid State Drive) or an HDD (Hard Disk Drive).

[0035] The operation unit 23 includes a user interface such as a touch panel, and receives operations from a user. The operation unit 23 outputs the received operation content to the processing unit 21. The display unit 24 includes a display such as a liquid crystal display or an organic EL display, and displays characters and images supplied from the processing unit 21.

[0036] The communication unit 25 executes communication processing with the power conversion device 10 in accordance with, for example, the RS-485 standard. The communication unit 25 also executes communication processing with the router device 7 in accordance with, for example, the Ethernet (registered trademark) standard. The router device 7 is connected to a network 8.

[0037] Network 8 is a general term for communication paths such as the Internet, dedicated lines, and VPNs (Virtual Private Networks), and the communication media and protocols are not important. For example, optical fiber networks, ADSL networks, CATV networks, mobile communication networks, wireless LANs, and wired LANs can be used as communication media. For example, TCP (Transmission Control Protocol) / IP (Internet Protocol), UDP (User Datagram Protocol) / IP, and Ethernet can be used as communication protocols.

[0038] The external connection management device 20 can be connected to an electricity retailer server 9 via a network 8. The electricity retailer server 9 is a server in which a system for managing the electricity usage status of consumers who have concluded electricity retail contracts is built.

[0039] The metered data acquisition unit 211 of the external connection management device 20 receives the amount of power received from the grid 2 (amount of power purchased from the electricity retailer), the amount of power flowed back to the grid 2 (amount of power sold to the electricity retailer), and the amount of power generated by the solar cell 5 from the control unit 15 of the power conversion device 10, and stores them in the metered data holding unit 221. Furthermore, the metered data acquisition unit 211 receives the amount of charge to the power storage unit 61 of the electric vehicle 6 and the amount of discharge from the power storage unit 61 from the control unit 33 of the vehicle power conversion device 30 via the control unit 15 of the power conversion device 10, and stores them in the metered data holding unit 221.

[0040] The measurement data acquisition unit 211 stores the origin of the power of the amount of power charged to the power storage unit 61 of the electric vehicle 6 in the power origin holding unit 222. When the power storage unit 61 of the electric vehicle 6 is being charged, if the solar cell 5 is not generating power, the origin of the power of the amount of power charged in that charging is entirely the amount of power received from the grid 2. When the power storage unit 61 of the electric vehicle 6 is being charged, if the solar cell 5 is generating power and no power is being purchased from the grid 2, the origin of the power of the amount of power charged in that charging is entirely the amount of power generated by the solar cell 5.

[0041] When charging the power storage unit 61 of the electric vehicle 6, if the solar cell 5 is generating power and also receiving power from the grid 2, the origin of the power for the charging is determined to be proportional to the ratio of the amount of power generated by the solar cell 5 to the amount of power received from the grid 2. Note that the amount of power generated by the solar cell 5 may be treated as being preferentially charged to the power storage unit 61 of the electric vehicle 6, or the amount of power received from the grid 2 may be treated as being preferentially charged to the power storage unit 61 of the electric vehicle 6.

[0042] The electric vehicle information acquisition unit 212 receives the vehicle ID of the electric vehicle 6 and the FCC (Full Charge Capacity), SOC, and SOH of the power storage unit 61 from the management unit 65 of the electric vehicle 6 via the charging cable C1, the control unit 33 of the vehicle power conversion device 30, and the control unit 15 of the power conversion device 10, and stores them in the electric vehicle information holding unit 223. Note that a battery ID may be acquired instead of the vehicle ID. When the management unit 65 of the electric vehicle 6 can acquire the accumulated mileage and number of years of operation of the electric vehicle 6 from an ECU (Electronic Control Unit) (not shown), the electric vehicle information acquisition unit 212 receives the accumulated mileage and number of years of operation of the electric vehicle 6, and stores them in the electric vehicle information holding unit 223.

[0043] Generally, in an electricity retail contract between an electricity retailer and a consumer, the electricity selling price is set lower than the electricity purchasing price. For example, the electricity purchasing price is set at 24 yen / kWh and the electricity selling price is set at 12 yen / kWh. Therefore, even if electricity purchased from grid 2 is stored in the power storage unit 61 of the electric vehicle 6 and the electricity stored in the power storage unit 61 is allowed to flow back to grid 2, the consumer cannot earn a profit.

[0044] However, the power storage unit 61 of the electric vehicle 6 can also be charged from a separate charging facility outside the home. Some large commercial facilities and the like have free charging stands installed. By using these charging stands, users of the electric vehicle 6 can charge the power storage unit 61 of the electric vehicle 6 free of charge (at the expense of the facility). Furthermore, in cases where the facility covers part of the electricity bill, users of the electric vehicle 6 can charge the power storage unit 61 of the electric vehicle 6 at a lower price than the general price.

[0045] Then, when the consumer returns home and connects the electric vehicle 6 to the vehicle power conversion device 30, the consumer can make a profit by backflowing the electricity that was charged for free or at low cost at an external charging station to the grid 2. If the retail electricity supplier does not sell electricity to facilities that have charging stations, the retail electricity supplier will not increase the amount of electricity they sell, but will increase the amount of electricity they buy from consumers, which could lead to a deterioration in profitability and the inability to operate as a business.

[0046] As a first measure against this, the electric vehicle charge / discharge amount management unit 213 limits the amount of power that can be reverse-flowed from the power storage unit 61 of the electric vehicle 6 to the grid 2 to equal to or less than the amount of power charged within the house. The amount of power charged within the house is the sum of the amount of power received from the grid 2 and the amount of power generated by the solar cell 5, and is stored in the measurement data holding unit 221.

[0047] The electric vehicle charge / discharge amount management unit 213 transmits an upper limit value of the amount of power that can be reversely flowed from the power storage unit 61 of the electric vehicle 6 to the grid 2 to the control unit 15 of the power conversion device 10. When the cumulative total of the reverse flow power from the power storage unit 61 of the electric vehicle 6 to the grid 2 reaches the upper limit value, the control unit 15 prohibits the reverse flow from the power storage unit 61 of the electric vehicle 6 to the grid 2. When the solar cell 5 is generating power, the amount of reverse flow power from the power storage unit 61 of the electric vehicle 6 to the grid 2 is a value obtained by subtracting the amount of power generated by the solar cell 5 from the amount of reverse flow power measured based on the current sensor CT1.

[0048] When it is desired to prevent a decrease in the amount of electricity sold by the retail electricity supplier to consumers due to the load 4 consuming electricity that has been charged free of charge or at low cost at an external charging facility, the electric vehicle charge / discharge amount management unit 213 sets an upper limit for the amount of electricity that can be discharged within the home from the electric storage unit 61 of the electric vehicle 6 to the amount of electricity charged within the home.

[0049] As a second measure, it is possible to change the purchase price of electricity flowing back from the power storage unit 61 of the electric vehicle 6 to the grid 2 depending on the origin of the electricity. The data transmission unit 214 periodically transmits the electricity usage status to the electricity retailer server 9 via the network 8. The electricity usage status transmitted to the electricity retailer server 9 includes the amount of electricity received from the grid 2 and the amount of electricity flowing back to the grid 2, which are read from the metering data storage unit 221. The amount of electricity flowing back to the grid 2 includes the amount of electricity flowing back from the solar cell 5 and the amount of electricity flowing back from the power storage unit 61 of the electric vehicle 6.

[0050] The data transmission unit 214 reads out the details of the origin of the electricity flowing back from the power storage unit 61 of the electric vehicle 6 from the electricity origin storage unit 222, and transmits the details to the electricity retailer server 9. After the start of the specified metering system, the electricity retailer will be able to calculate the electricity charges to be billed to consumers based on the electricity usage status received from the external connection management device 20 of the electricity management system 1. The amount of electricity received from the grid 2 and the amount of electricity flowing back to the grid 2 may be received from a smart meter (not shown).

[0051] The electricity retailer sets the unit price of grid-derived electricity, of the amount of electricity flowing backward from the power storage unit 61 of the electric vehicle 6, to be lower than the unit price of solar-derived electricity. The unit price of electricity derived from charging equipment outside the home is set even lower than the unit price of grid-derived electricity within the home, or set to 0 yen. When the electricity stored in the power storage unit 61 of the electric vehicle 6 is a mixture of grid-derived electricity and solar-derived electricity, the electricity retailer server 9 first allocates solar-derived electricity to the electricity flowing backward from the power storage unit 61 of the electric vehicle 6. After the solar-derived electricity runs out, the grid-derived electricity is allocated.

[0052] After the solar power and the grid power have run out, the power that flows back from the power storage unit 61 of the electric vehicle 6 is determined to be power that has been charged from a charging facility outside the home. When used in conjunction with the above-mentioned first measure, the reverse power flow from the power storage unit 61 of the electric vehicle 6 is prohibited after the solar power and the grid power have run out.

[0053] 4(a)-(b) are diagrams showing a specific example of the transition of the origin of the power stored in the power storage unit 61 of the electric vehicle 6 and the transition of the amount of reverse power flow possible from the power storage unit 61 according to the first embodiment. For convenience, in Fig. 4(a)-(b), the diagram is shown with newly charged power added to the top and discharged power subtracted from the top. Note that the origin of the power stored in the power storage unit 61 cannot be electrically distinguished, and the origin is distinguished by numerical management.

[0054] Fig. 4(a) shows an example in which the upper limit of the amount of power that can be flowed back from the power storage unit 61 of the electric vehicle 6 to the grid 2 is set to the amount of power charged inside the home. For simplicity, the amount of power will be explained using normalized values. Hg indicates the power charged from the grid 2 at home, and Og indicates the power charged from the grid 2 at an outside charger. In the example shown in Fig. 4(a), it is assumed that the power charged from the outside charger is consumed preferentially while driving.

[0055] At home, 4 units of power are charged from grid 2 to the power storage unit 61 of the electric vehicle 6. As a result, the power stored in the power storage unit 61 becomes 4, and the possible amount of reverse flow becomes 4. Next, the electric vehicle 6 is driven, and 1 unit of power is consumed from the power storage unit 61. The power stored in the power storage unit 61 becomes 3, and the possible amount of reverse flow remains at 4. Next, 2 units of power are charged from grid 2 to the power storage unit 61 of the electric vehicle 6 using an external charger. The power stored in the power storage unit 61 becomes 5, and the possible amount of reverse flow remains at 4. Next, the electric vehicle 6 is driven to home, and 1 unit of power is consumed from the power storage unit 61. The power stored in the power storage unit 61 becomes 4, and the possible amount of reverse flow remains at 4. Note that if the power stored in the power storage unit 61 at the time of returning home is less than 4, the possible amount of reverse flow is reduced to the power stored in the power storage unit 61. Next, the power storage unit 61 of the electric vehicle 6 is connected to the vehicle power conversion device 30 at home, and power 2 is discharged to the grid 2. The power stored in the power storage unit 61 becomes 2, and the possible amount of reverse flow becomes 2.

[0056] Fig. 4(b) shows an example in which the upper limit of the amount of power that can be flowed back from the power storage unit 61 of the electric vehicle 6 to the grid 2 is set to the amount of power charged from solar power within the home. Hr indicates the power charged from the solar cell 5 at home. In the example shown in Fig. 4(b), while driving, priority is given to consuming power charged from an external charger, followed by priority given to consuming power charged from the grid 2 at home, and finally consuming power charged from the solar cell 5 at home.

[0057] At home, the power storage unit 61 of the electric vehicle 6 is charged with 3 electric power from the grid 2 and 1 electric power from the solar cell 5. As a result, the power stored in the power storage unit 61 becomes 4, and the possible amount of reverse flow becomes 1. Next, the electric vehicle 6 is driven, and 1 electric power from the power storage unit 61 is consumed. The power stored in the power storage unit 61 becomes 3, and the possible amount of reverse flow remains 1. Next, 2 electric power is charged from the grid 2 to the power storage unit 61 of the electric vehicle 6 using an external charger. The power stored in the power storage unit 61 becomes 5, and the possible amount of reverse flow remains 1. Next, the electric vehicle 6 is driven to home, and 1 electric power from the power storage unit 61 is consumed. The power stored in the power storage unit 61 becomes 4, and the possible amount of reverse flow remains 1. Next, the power storage unit 61 of the electric vehicle 6 is connected to the vehicle power conversion device 30 at home, and 1 electric power is discharged to the grid 2. The amount of power stored in power storage unit 61 becomes 3, and the possible amount of reverse flow becomes 0.

[0058] The upper limit of the amount of power that can be flowed backward from the power storage unit 61 of the electric vehicle 6 to the grid 2 may be set by a carbon dioxide emission value. In this case, the electric vehicle charge / discharge amount management unit 213 converts the amount of power charged to the power storage unit 61 of the electric vehicle 6, acquired by the metered data acquisition unit 211, into a carbon dioxide emission value based on a carbon dioxide emission coefficient according to the origin of the power, and stores the converted carbon dioxide emission value in the metered data holding unit 221.

[0059] For example, the Japan Photovoltaic Energy Association (JPEA)'s labeling guidelines stipulate that the carbon dioxide emission coefficient for crystalline silicon solar cells is 45.5g-CO2 / kWh, that for amorphous silicon solar cells is 28.6g-CO2 / kWh, that for CIGS / CIS solar cells is 26.0g-CO2 / kWh, and that for electricity supplied from Grid 2 is 463g-CO2 / kWh.

[0060] The electric vehicle charge / discharge amount management unit 213 may set an upper limit of the carbon dioxide emission value for each origin of the electricity stored in the power storage unit 61 of the electric vehicle 6, or may set one upper limit of the carbon dioxide emission value for all the electricity stored in the power storage unit 61 of the electric vehicle 6. In the latter case, the carbon dioxide emission value of the electricity stored in the power storage unit 61 is calculated by multiplying by a carbon dioxide emission coefficient adjusted according to the ratio of the origin of the electricity. Note that the electric vehicle charge / discharge amount management unit 213 may treat electricity charged from a distributed power source for which a carbon dioxide emission coefficient is not set as electricity that cannot be reversely flowed.

[0061] Incidentally, some electricity retailers change their rate plans based on at least one of the ownership status of the electric vehicle 6, the usage status of the electric vehicle 6, and the storage capacity of the power storage unit 61 of the electric vehicle 6. For example, there is a retailer that provides preferential plans to owners of electric vehicles 6. As a specific example, a rate plan is provided for general consumers with a power purchase price of 24 yen / kWh and a power selling price of 12 yen / kWh, and a rate plan is provided for owners of electric vehicles 6 with a power purchase price of 22 yen / kWh and a power selling price of 14 yen / kWh.

[0062] The reasons for giving preferential treatment to owners of electric vehicles 6 include the fact that owners of electric vehicles 6 tend to purchase more electricity and that the power storage unit 61 of the electric vehicle 6 can be used as the adjustment power of the VPP. Note that electricity retailers that partner with manufacturers selling electric vehicles 6 may set up preferential treatment plans to encourage sales of electric vehicles 6.

[0063] For an electricity retailer that places importance on the fact that owners of electric vehicles 6 purchase more electricity as a reason for giving preferential treatment to owners of electric vehicles 6, if the electric vehicle 6 is sold and the electric vehicle 6 is no longer present at the consumer's home, the reason for offering a preferential plan will collapse. Also, if the frequency of use of the electric vehicle 6 decreases, the amount of purchased electricity will decrease, and the reason for offering the preferential plan will weaken.

[0064] For electricity retailers who place importance on using the power storage unit 61 of the electric vehicle 6 as the adjustment power of the VPP as a basis for giving preferential treatment to owners of electric vehicles 6, as the SOH decreases, the ability of the power storage unit 61 as an adjustment power decreases, and the basis for offering preferential plans weakens. Also, if the frequency of use of the electric vehicle 6 decreases, it becomes difficult to use it as an adjustment power of the VPP, and the basis for offering preferential plans weakens. If the frequency of use of the electric vehicle 6 is low, the power storage unit 61 is always maintained in a state close to a fully charged state, and the ability to absorb power from the grid 2 decreases. If the power storage unit 61 of the electric vehicle 6 cannot be incorporated into the VPP, there will be no basis for electricity retailers who also function as aggregators to give preferential treatment to owners of electric vehicles 6 in terms of the unit price of electricity purchase.

[0065] 3, the data transmission unit 214 of the external connection management device 20 periodically reads out electric vehicle information from the electric vehicle information storage unit 223, and transmits the read out electric vehicle information to the electricity retailer server 9 via the network 8. If the electric vehicle 6 has not been used for a predetermined period (e.g., one month) or more, the electricity retailer server 9 does not apply the preferential plan to the non-use period. Note that the preferential plan may be terminated by assuming that the consumer no longer owns the electric vehicle 6.

[0066] The usage status of the electric vehicle 6 can be determined, for example, from the communication history between the control unit 33 of the vehicle power conversion device 30 and the management unit 65 of the electric vehicle 6. At that time, it is desirable to check whether the same vehicle ID is included in each communication history.

[0067] The usage status of the electric vehicle 6 can also be determined based on whether the amount of charge / discharge to the power storage unit 61 of the electric vehicle 6 in a predetermined period is zero. In this case, even if the specifications do not allow communication between the electric vehicle 6 and the vehicle power conversion device 30, the usage status of the electric vehicle 6 can be estimated.

[0068] Furthermore, a usage rate management unit (not shown) of the external connection management device 20 may determine whether the electric vehicle 6 has not been used for a predetermined period or longer. The usage rate management unit stores the period when the electric vehicle 6 has not been used for a predetermined period or longer in the electric vehicle information storage unit 223 as a period during which the preferential plan is not applied. When the electric vehicle 6 has not been used for the predetermined period, the usage rate management unit causes the display unit 24 to display a message indicating that at least one of an increase in the electricity purchase price and a decrease in the electricity sale price will be implemented due to the termination of the preferential plan. The data transmission unit 214 transmits information indicating the application period and non-application period of the preferential plan to the electricity retailer server 9, including the electric vehicle information.

[0069] Furthermore, when the amount of charge / discharge to the power storage unit 61 of the electric vehicle 6 during a predetermined period is below a reference value, the electricity retailer server 9 determines that the frequency of use of the electric vehicle 6 is low, and does not apply the preferential plan to the period of low usage. Note that the usage rate management unit of the external connection management device 20 may determine whether the amount of charge / discharge to the power storage unit 61 of the electric vehicle 6 during a predetermined period is below a reference value.

[0070] In addition, when the SOH of the power storage unit 61 of the electric vehicle 6 falls to a set value (e.g., 70%), the retail electricity business operator server 9 determines that the power storage unit 61 no longer meets the required level as the adjustment power of the VPP, and terminates the preferential plan.

[0071] An FCC estimation unit (not shown) of the external connection management device 20 compares the charge / discharge amount of the power storage unit 61 over a certain period with the increase / decrease in the SOC of the power storage unit 61 to estimate the current FCC. This makes it possible to verify the authenticity of the current FCC of the power storage unit 61 of the electric vehicle 6. When the current FCC of the power storage unit 61 of the electric vehicle 6 falls below a set value, the electricity retailer server 9 determines that the power storage unit 61 no longer meets the required level as the adjustment power of the VPP, and ends the preferential plan. This process is effective when the FCC and SOH of the power storage unit 61 cannot be obtained from the management unit 65 of the electric vehicle 6.

[0072] (Embodiment 2) 5 is a diagram for explaining the power management system 1 according to the embodiment 2. In the embodiment 2, the external connection management device 20 or the electricity retailer server 9 cooperates with the charger management server 75 and the integrated power management server 20u to manage the origin of the power stored in the power storage unit 61 of a specific electric vehicle 6, including the power charged from an external charging facility 70.

[0073] Charging facility 70 according to the second embodiment has a function of connecting to network 8. For example, charging facility 70 is connected to network 8 via a LAN in a facility where charging facility 70 is installed. Charger management server 75 is a server in which a system for managing charging facilities 70 installed in multiple locations is built.

[0074] The integrated power management server 20u is a server in which a system is built to provide various services to users of the power conversion device 10 via the network 8. The integrated power management server 20u is operated, for example, by the manufacturer of the power conversion device 10. The integrated power management server 20u may be a company server installed in a data center or a company's own facility, or may be a cloud server based on a cloud service contract. The same applies to the charger management server 75 and the electricity retailer server 9. Data is previously linked between the electricity retailer server 9, the charger management server 75, and the integrated power management server 20u regarding vehicle IDs registered with the electricity retailer.

[0075] The charging equipment 70 is connected to the system 2 and can receive power supply from the system 2. In addition, if a solar power generation system is installed in the facility where the charging equipment 70 is installed, the charging equipment 70 can also receive power supply from the solar power generation system.

[0076] The electric vehicle 6 can be connected to the charging equipment 70 via a charging cable. The management unit 65 of the electric vehicle 6 can communicate with a control unit (not shown) of the charging equipment 70 via a communication line in the charging cable. The control unit of the charging equipment 70 acquires a vehicle ID and SOC from the management unit 65 of the electric vehicle 6 connected via the charging cable. The control unit of the charging equipment 70 measures the amount of charge to the power storage unit 61 of the electric vehicle 6. After charging of the power storage unit 61 of the electric vehicle 6 is completed, the control unit of the charging equipment 70 transmits charging information including at least the vehicle ID and the amount of charge to the charger management server 75 via the network 8. Note that when the charging equipment 70 is connected to a solar power generation system, the control unit of the charging equipment 70 also includes the origin of the power of the amount of charge to the power storage unit 61 of the electric vehicle 6 in the charging information.

[0077] When the charger management server 75 receives the charging information including the data-linked vehicle ID, it transmits the charging information to the integrated power management server 20u via the network 8. The integrated power management server 20u transmits the received charging information to at least one of the external connection management device 20 and the electricity retailer server 9 via the network 8.

[0078] 6(a)-(b) are diagrams showing specific examples of the transition of the origin of the power stored in the power storage unit 61 of the electric vehicle 6 and the transition of the amount of reverse power flow possible from the power storage unit 61 according to the second embodiment. Fig. 6(a) shows an example in which the upper limit of the amount of power that can be reversed from the power storage unit 61 of the electric vehicle 6 to the grid 2 is set to the amount of power charged within the home.

[0079] At home, 4 electric power is charged from the grid 2 to the power storage unit 61 of the electric vehicle 6. As a result, the power stored in the power storage unit 61 becomes 4, and the possible amount of reverse flow becomes 4. Next, the electric vehicle 6 is driven to consume 1 electric power from the power storage unit 61. The power stored in the power storage unit 61 becomes 3, and the possible amount of reverse flow remains at 4. Next, 2 electric power is charged from the grid 2 to the power storage unit 61 of the electric vehicle 6 at the external charging equipment 70. The power stored in the power storage unit 61 becomes 5, and the possible amount of reverse flow becomes 3. In the example shown in FIG. 6(a), the external connection management device 20 can receive the amount of power charged at the external charging equipment 70 via the integrated power management server 20u, so that it is possible to distinguish between the amount of power charged at home and the amount of power charged at the external charging equipment 70.

[0080] Next, the electric vehicle 6 is driven to the home, and 1 of the power from the power storage unit 61 is consumed. The power stored in the power storage unit 61 becomes 4, and the possible reverse flow amount remains 3. If the power stored in the power storage unit 61 upon returning home is less than 4, the possible reverse flow amount is reduced to the power stored in the power storage unit 61. Next, the power storage unit 61 of the electric vehicle 6 is connected to the vehicle power conversion device 30 at the home, and 2 of the power is discharged to the grid 2. The power stored in the power storage unit 61 becomes 2, and the possible reverse flow amount becomes 2.

[0081] FIG. 6(b) shows an example in which the upper limit of the amount of power that can be discharged from the power storage unit 61 of the electric vehicle 6 to the home is set to the amount of power charged from solar power. The amount that can be discharged to the home is determined by the sum of the amount of power consumed by the load 4 and the amount of power that flows backward to the grid 2. Or indicates the power charged from the solar cells of the facility at the external charging equipment 70. In the example shown in FIG. 6(b), while traveling, priority is given to consuming power charged from the grid 2 at the external charging equipment 70, then priority is given to consuming power charged from the grid 2 at home, then priority is given to consuming power charged from the solar cells of the facility at the external charging equipment 70, and finally priority is given to consuming power charged from the solar cells 5 at home.

[0082] FIG. 6(b) shows an example in which, in order to achieve RE100, the upper limit of the amount of electricity that can be discharged from the power storage unit 61 of the electric vehicle 6 to the home is set to the amount of electricity charged from solar power at the charging facility 70 outside the home.

[0083] At home, the power storage unit 61 of the electric vehicle 6 is charged with 3 electric power from the grid 2 and 1 electric power from the solar cell 5. As a result, the power stored in the power storage unit 61 becomes 4, and the amount that can be discharged to the home becomes 1. Next, the electric vehicle 6 is driven, and 1 electric power from the power storage unit 61 is consumed. The power stored in the power storage unit 61 becomes 3, and the amount that can be discharged to the home remains 1. Next, at the external charging equipment 70, the power storage unit 61 of the electric vehicle 6 is charged with 1 electric power from the grid 2 and 1 electric power from the solar cell. The power stored in the power storage unit 61 becomes 5, and the amount that can be discharged to the home becomes 2. In the example shown in FIG. 6(b), the external connection management device 20 can identify the origin of the power charged at the external charging equipment 70 via the integrated power management server 20u, and therefore the amount of power that has been charged from solar power at the external charging equipment 70 can be identified.

[0084] Next, the electric vehicle 6 is driven to the home, and 1 of the power in the power storage unit 61 is consumed. The power stored in the power storage unit 61 becomes 4, and the amount that can be discharged to the home remains 2. Next, the power storage unit 61 of the electric vehicle 6 is connected to the vehicle power conversion device 30 at the home, and 2 of the power is discharged to the home. The power stored in the power storage unit 61 becomes 2, and the amount that can be discharged to the home becomes 0.

[0085] In addition, when the upper limit of the amount of power that can be discharged from the power storage unit 61 of the electric vehicle 6 to the home is set to the amount of power charged from solar power at home in order to aim for a self-sufficient property, the amount that can be discharged to the home changes from 1 → 1 → 1 → 1 → 0. In addition, when the upper limit of the amount of power that can be reversely flowed from the power storage unit 61 of the electric vehicle 6 to the grid 2 is set to the amount of power charged from solar power at home, the amount of reversely flowable changes from 1 → 1 → 1 → 1 → 0. In addition, when power discharged from the power storage unit 61 of the electric vehicle 6 to the home is consumed by the load 4, the amount of reversely flowable does not decrease, but the amount that can be discharged to the home decreases.

[0086] Note that all reverse power flow from the power storage unit 61 of the electric vehicle 6 to grid 2 may be permitted, and the electricity retailer may change the unit price of electricity that it purchases from consumers for each source of electricity. For example, the prices may be set in the order of home solar power → home grid 2 → outdoor solar power → outdoor grid 2. The electricity retailer server 9 can grasp the origins of all of the electricity stored in the power storage unit 61 of the electric vehicle 6, based on the charging information from the external connection management device 20 and the integrated power management server 20u.

[0087] Furthermore, the origin of the power stored in the power storage unit 61 of the electric vehicle 6 may be managed by the management unit 65 of the electric vehicle 6. When the electric vehicle 6 and an external charging facility 70 are connected by a charging cable and charging from the charging facility 70 to the power storage unit 61 is completed, the management unit 65 of the electric vehicle 6 acquires charging information including the charge amount and the origin of the power from a control unit (not shown) of the charging facility 70 via a communication line in the charging cable. The management unit 65 stores the acquired charging information in a non-volatile memory (not shown).

[0088] When the electric vehicle 6 and the vehicle power conversion device 30 are connected by the charging cable C1, the metered data acquisition unit 211 of the external connection management device 20 receives the charging information stored in the non-volatile memory of the management unit 65 via the control unit 33 of the vehicle power conversion device 30 and the control unit 15 of the power conversion device 10, and stores it in the metered data holding unit 221. Note that the management unit 65 of the electric vehicle 6 may manage the origin of all of the power stored in the power storage unit 61, including the power charged from the home grid 2 and the solar cell 5.

[0089] As described above, according to the embodiment, it is possible to ensure the benefits of both the consumer and the electricity retailer while permitting reverse power flow from the power storage unit 61 of the electric vehicle 6. It is possible to prevent a deterioration in the profitability of the electricity retailer caused by reverse power flow from the home of electricity that has been charged free of charge or at low cost by the charging facility 70 outside the home to the power storage unit 61 of the electric vehicle 6.

[0090] In addition, by managing the origin of the electricity stored in the power storage unit 61 of the electric vehicle 6, the retail electricity supplier can appropriately manage the amount of electricity that flows back from the power storage unit 61 of the electric vehicle 6 to the grid 2 and the unit price of electricity to be purchased from consumers.

[0091] Moreover, in the second embodiment, the amount of power charged in the charging facility 70 outside the home can also be managed. This makes it possible to prevent a large amount of power that can be reversely flowed from the power storage unit 61 to the grid 2 from remaining, for example, in a case where the power stored in the power storage unit 61 of the electric vehicle 6 is completely consumed outside the home and then recharged in the charging facility 70 outside the home before returning. Note that, if the origin of the power stored in the power storage unit 61 of the electric vehicle 6 is entirely managed by the management unit 65 of the electric vehicle 6, it is also possible to grasp the amount of power consumed by the traveling of the electric vehicle 6 and the amount of power that is naturally decreased.

[0092] The present disclosure has been described above based on the embodiments. The embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component and each processing step, and that such modifications are also within the scope of the present disclosure.

[0093] FIG. 7 is a diagram for explaining the power management system 1 according to a modification of the first embodiment. In the first modification, an AC-link vehicle power conversion device 30a is used instead of a DC-link vehicle power conversion device 30. The AC-link vehicle power conversion device 30a includes a DC / AC converter 31a instead of a DC / DC converter 31. The AC side of the DC / AC converter 31a is connected to a power line between the power conversion device 10 and the distribution board 3. A circuit switching unit may be provided at the connection portion. The control unit 33 of the vehicle power conversion device 30a is connected to the router device 7 by wire (for example, a LAN cable) or wirelessly (for example, Wi-Fi). The control unit 33 of the vehicle power conversion device 30a can communicate with the external connection management device 20, the retail electricity business operator server 9, or the integrated power management server 20u (not shown in FIG. 7) via the router device 7. The control unit 33 of the vehicle power conversion device 30a and the external connection management device 20 may be directly connected by a communication line.

[0094] 1, 5, and 7 show configuration examples in which the external connection management device 20 is installed outside the power conversion device 10, but the external connection management device 20 may be built into the housing of the power conversion device 10. Also, a configuration in which the vehicle power conversion device 30 shown in FIGS. 1 and 5 is built into the housing of the power conversion device 10 is also possible. Also, a stationary storage battery or a household fuel cell can be connected to the power conversion device 10. Either of these is connected to the DC bus Bd via a converter.

[0095] The solar cell 5 is an example of a power generation device that generates power using renewable energy. A wind power generator, a micro hydroelectric generator, or the like may be used instead of the solar cell 5. When an AC output generator is used, an AC / DC converter is used instead of the DC / DC converter 11. The power storage unit 61 of the electric vehicle 6 is an example of a portable power storage device. For example, it may be a battery pack mounted on an electric motorcycle or electric bicycle, or a battery pack mounted on a multicopter (drone).

[0096] A part or all of the processes executed by the external connection management device 20 described in the second embodiment may be executed by the integrated power management server 20u. Furthermore, the data held in the metered data holding unit 221, the electric power derived holding unit 222, and the electric vehicle information holding unit 223 of the external connection management device 20 may also be stored in the integrated power management server 20u. For example, short-term data may be held in the external connection management device 20, and long-term data may be stored in the integrated power management server 20u.

[0097] In cases where the demand plan submitted by a retail electricity supplier to a transmission and distribution utility exceeds the power generation plan submitted by a power generation supplier to the transmission and distribution utility, the retail electricity supplier may be required to pay an imbalance settlement fee to the general transmission and distribution utility. In this case, if the consumer supplies electricity to grid 2, the excess demand will decrease, and the imbalance settlement fee can be reduced.

[0098] In the first and second embodiments, an example has been described in which the upper limit of the amount of power that can be reversely flowed from the power storage unit 61 of the electric vehicle 6 to the grid 2 is set to the amount of power charged in the home. In this regard, in the case of excess demand, the electricity retailer server 9 may transmit, via the network 8, to the external connection management device 20, a command value that exceeds the amount of power charged in the home, as the upper limit of the amount of power that can be reversely flowed from the power storage unit 61 of the electric vehicle 6 to the grid 2. Furthermore, a command value for the upper limit of the amount of power that can be reversely flowed from the power storage unit 61 of the electric vehicle 6 to the grid 2 may be transmitted to the external connection management device 20 from a server of an aggregator or electricity transmission and distribution company other than the retailer.

[0099] The embodiment may be specified by the following items.

[0100] [Item 1] a power conversion unit (10) connected between a power generation device (5) based on renewable energy and a grid (2) and capable of connecting to a portable power storage device (61); a management unit (20) that stores and manages an amount of power received from the grid (2) and an amount of power flowed back to the grid (2); the power storage device (61) is capable of being charged from the power generation device (5), being charged from the grid (2), and providing reverse power flow to the grid (2), and is also capable of being charged from another charging facility (70); The power management system (1) is characterized in that the management unit (20) manages the origin of the power stored in the power storage device (61). This makes it possible to secure the benefits of both the consumer and the electricity retailer while permitting reverse power flow from the portable power storage device (61) to the grid (2). [Item 2] The power management system (1) described in item 1, wherein the management unit (20) transmits a breakdown of the origin of the power flowed back to the grid (2) or the power discharged into the home from the power storage device (61) to a management system (9) of a retail electricity supplier via a network (8). This enables the electricity retailer to appropriately manage the amount of power that is reversely flowed from the portable power storage device (61) to the grid (2) and the unit price of the power that is purchased from consumers. [Item 3] 3. The power management system (1) according to item 1 or 2, wherein the management unit (20) limits an amount of power that can be reverse-flowed from the power storage device (61) to the grid (2) to an amount equal to or less than an amount of power stored within the home. This makes it possible to prevent a deterioration in the profitability of the retail electricity supplier, which would otherwise occur if electricity, which has been charged in the portable power storage device (61) for free or at low cost by an external charging facility (70), were to be reverse-flowed to the home grid (2). [Item 4] The power management system (1) according to any one of items 1 to 3, characterized in that when the power storage device (61) is charged from the other charging equipment (70) installed outside the home, the management unit (20) acquires the amount of power charged from the charging equipment (70) to the power storage device (61) from the charging equipment (70) via a network (8). This makes it possible to manage the power stored in the portable power storage device (61) from the charging facility 70 outside the home. [Item 5] The management unit (20) converts the power flowed backward from the power storage device (61) to the grid (2) into a carbon dioxide emission value based on a carbon dioxide emission coefficient for each source and manages the power, 5. The power management system (1) according to any one of items 1 to 4, wherein an upper limit value for allowing reverse power flow from the power storage device (61) to the grid (2) is set based on a carbon dioxide emission value. This makes it possible to appropriately comply with carbon dioxide emission regulations. [Item 6] 6. The power management system (1) according to any one of items 1 to 5, wherein the management unit (20) receives a command value of an upper limit value for which reverse power flow is permitted from the power storage device (61) to the grid (2) from a higher-level device (9) via a network (8). This allows the portable power storage device (61) to be used to stabilize the power grid (2). [Item 7] The power storage device (61) is an electricity storage unit (61) mounted on an electric vehicle (60), The power management system (1) according to any one of items 1 to 6, wherein the management unit (20) acquires a vehicle ID and a State of health (SOH) from a management unit (20) in the electric vehicle (60) via a charging cable (C1), and transmits the information to a management system (9) of a retail electricity supplier via a network (8). This makes it possible to appropriately manage the conditions for applying the preferential plan to the electric vehicle (60). [Item 8] A power conversion device (10) that is connected between a power generation device (5) based on renewable energy and a grid (2) and to which a portable power storage device (61) can be connected, and an integrated management system (20u) that is connected via a network (8), a management unit (20) that receives, via a network (8), from the power conversion device (10) an amount of power received from the grid (2) by the power conversion device (10) and an amount of power that the power conversion device (10) reversely flows to the grid (2), and manages the amount of power received from the power conversion device (10), the power storage device (61) is capable of being charged from the power generation device (5), being charged from the grid (2), and providing reverse power flow to the grid (2), and is also capable of being charged from another charging facility (70); The management unit (20) is an integrated management system (20u) that manages the origin of the power stored in the power storage device (61). This makes it possible to secure the benefits of both the consumer and the electricity retailer while permitting reverse power flow from the portable power storage device (61) to the grid (2). [Explanation of symbols]

[0101] 1 Power management system, 2 System, 3 Distribution board, 4 Load, 5 Solar cell, 6 Electric vehicle, 61 Power storage unit, 62 Inverter, 63 Motor, 64 DC / DC converter, 65 Management unit, RY1 Contact relay, RY2 Charging relay, C1 Charging cable, 7 Router device, 8 Network, 9 Retail electricity supplier server, 10 Power conversion device, 11 DC / DC converter, 12 Inverter, 13 Converter control circuit, 14 Inverter control circuit, 15 Control unit, Bd DC bus, CT1 Current sensor, 20 External connection management device, 21 Processing unit, 211 Measurement data acquisition unit, 212 Electric vehicle information acquisition unit, 213 Electric vehicle charge / discharge amount management unit, 214 Data transmission unit, 22 Memory unit, 221 Measurement data retention unit, 222 Electric power source storage unit, 223 electric vehicle information storage unit, 23 operation unit, 24 display unit, 25 communication unit, 20u integrated power management server, 30 vehicle power conversion device, 31 DC / DC converter, 31a DC / AC converter, 32 converter control circuit, 33 control unit, 70 charging equipment, 75 charger management server.

Claims

1. a power conversion unit connected between a power generation device based on renewable energy and a grid and capable of connecting to a power storage unit of an electric vehicle; A management unit that stores and manages an amount of power received from the grid and an amount of power flowed back to the grid, the power storage unit is capable of being charged by the power generation device, being charged from the grid, and receiving reverse power flow to the grid, and is also capable of being charged by another charging facility; The management unit manages the origin of the electricity stored in the electricity storage unit by taking into account consumption of electricity from the electricity storage unit due to traveling of the electric vehicle.

2. The power management system according to claim 1, characterized in that the management unit transmits a breakdown of the origin of the power that has been reverse-flowed to the grid or the power that has been discharged into the home from the storage unit to a management system of a retail electricity supplier via a network.

3. 3 . The power management system according to claim 1 , wherein the management unit limits an amount of power that can be reversely flowed from the power storage unit to the grid to an amount equal to or less than an amount of power stored in the home. 4 .

4. The power management system according to any one of claims 1 to 3, characterized in that when the storage unit is charged from the other charging equipment installed outside the home, the management unit obtains the amount of power charged from the charging equipment to the storage unit from the charging equipment via a network.

5. The management unit converts the power flowed backward from the storage unit to the grid into a carbon dioxide emission value based on a carbon dioxide emission coefficient for each source and manages the power, 5. The power management system according to claim 1, wherein an upper limit value for allowing a reverse power flow from the power storage unit to the grid is set based on a carbon dioxide emission value.

6. 6. The power management system according to claim 1, wherein the management unit receives a command value for an upper limit value of an allowable reverse power flow from the power storage unit to the grid from a higher-level device via a network.

7. An energy management system as described in any one of claims 1 to 6, characterized in that the management unit obtains a vehicle ID and SOH (State Of Health) from a management unit in the electric vehicle via a charging cable, and transmits them to a management system of a retail electricity supplier via a network.

8. An energy management system as described in any one of claims 1 to 6, wherein the management unit manages the consumption of energy in the energy storage unit due to the running of the electric vehicle by giving priority to consumption of energy charged from the other charging equipment.

9. An integrated management system connected via a network to a power conversion device that is connected between a power generation device based on renewable energy and a grid and to which a power storage unit of an electric vehicle can be connected, a management unit that receives the amount of power received by the power conversion device from the grid and the amount of power that the power conversion device reversely flows to the grid from the power conversion device via a network and manages the amount of power received by the power conversion device from the grid, the power storage unit is capable of being charged by the power generation device, being charged from the grid, and receiving reverse power flow to the grid, and is also capable of being charged by another charging facility; An integrated management system, wherein the management unit manages the origin of the electricity stored in the power storage unit by taking into account consumption of electricity from the power storage unit due to the running of the electric vehicle.

10. An integrated management system as described in Claim 9, wherein the management unit manages the consumption of electricity in the storage unit due to the operation of the electric vehicle by giving priority to electricity charged from the separate charging equipment.

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