Charging / discharging system, control method for charging / discharging system, and computer program

Abstract

To provide a charging / discharging system for charging and discharging a vehicle's power storage device, which can suppress an increase in power received from a power grid due to charging of the vehicle's power storage device and can efficiently operate a distributed power source and the vehicle's power storage device.SOLUTION: A charging / discharging system for a distributed power source that can be connected to an electric power grid 1 includes a conversion circuit 22, a control unit 25 that controls the conversion circuit 22, and a charge / discharge unit 51 that is connected to the electric power grid 1 and the conversion circuit 22 and is capable of charging a vehicle power storage device. The control unit 25 controls the output Iac_2 of the conversion circuit 22 such that the received power Pinv from the electric power grid 1 becomes a target value while the charge / discharge unit 51 is charging the vehicle power storage device.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a charging and discharging system for charging and discharging a power storage device of a vehicle. [Background technology]

[0002] In recent years, vehicle electrification has progressed due to environmental considerations, and charging infrastructure for electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs) is being built.

[0003] There is also a demand for a system that can supply power to an electrical load in the event of a power outage due to a disaster, etc. Patent Document 1 discloses a bidirectional charger / discharger (charging / discharging stand) that not only charges an on-board power storage device but also discharges power from the on-board power storage device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-10442 Summary of the Invention [Problem to be solved by the invention]

[0005] From the viewpoint of energy management, there is room for improvement in order to efficiently operate distributed power sources such as photovoltaic power generation systems (PV systems) and vehicle power storage devices.

[0006] One embodiment of the present invention provides a charge / discharge system for charging and discharging a power storage device of a vehicle. [Means for solving the problem]

[0007] According to one aspect of the present invention, a charging / discharging system for a distributed power source connectable to an electric power grid includes a conversion circuit, a control unit for controlling the conversion circuit, and a charge / discharge unit connected to the electric power grid and the conversion circuit and capable of charging a vehicle power storage device, wherein the control unit controls the output of the conversion circuit so that received power from the electric power grid reaches a target value while the charge / discharge unit is charging the vehicle power storage device. [Effects of the Invention]

[0008] According to the above aspect, it is possible to suppress an increase in power received from the power grid due to charging of the vehicle power storage device, and it is possible to efficiently operate the distributed power sources and the vehicle power storage device. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a block diagram of a charging / discharging system. [Figure 2] FIG. 2 is a perspective view of a charging / discharging station. [Figure 3] FIG. 2 is a perspective view of the charging / discharging stand. [Figure 4] FIG. 2 is a block diagram of a charging / discharging station. [Figure 5] FIG. 10 is a diagram illustrating constant received power control during charging by the charge / discharge system. [Figure 6] FIG. 2 is a diagram illustrating variable control of received power by the charge / discharge system. [Figure 7] FIG. 1 is a diagram illustrating an overview of a remote monitoring system. [Figure 8] FIG. 1 is a diagram showing a power conditioner with a storage battery that is integrally provided with a charge / discharge unit. [Figure 9] FIG. 1 is a block diagram of a charge / discharge system using a power conditioner with a storage battery that is integrally provided with a charge / discharge unit. DETAILED DESCRIPTION OF THE INVENTION

[0010] A charging / discharging system for a distributed power source that can be connected to an electric power grid includes a conversion circuit, a control unit that controls the conversion circuit, and a charge / discharge unit that is connected to the electric power grid and the conversion circuit and is capable of charging a vehicle power storage device. The control unit controls the output of the conversion circuit so that the power received from the electric power grid becomes a target value while the charge / discharge unit is charging the vehicle power storage device.

[0011] Here, the distributed power source may be a small-scale power generation facility that is dispersed and located adjacent to an area where electricity is demanded, and specifically, may be a solar power generation panel, a wind power generation device, or a biomass power generation device. The conversion circuit and control unit may be provided in a power conditioner (PCS), but are not limited to this configuration. The charge / discharge unit may be provided in a charger / discharger separate from the power conditioner, but are not limited to this configuration.

[0012] The vehicle power storage device may be a power storage device for driving a vehicle mounted on an electric vehicle without an internal combustion engine (for example, a battery electric vehicle (BEV), an AGV, or a vehicle similar thereto). Alternatively, the vehicle power storage device may be a power storage device for driving a vehicle mounted on a plug-in hybrid electric vehicle (PHEV) or a hybrid electric vehicle (HEV) that also uses an internal combustion engine. The vehicle power storage device is not limited to one that is fixedly mounted on the vehicle, but may be one that is detachable from the vehicle.

[0013] According to the charging / discharging system having the above configuration, the control unit controls the output of the conversion circuit so that the received power reaches a target value during charging, and assists the power for charging with the output obtained by converting power generated by, for example, a distributed power source. Therefore, the vehicle power storage device can be charged without excessively increasing the power received from the power grid, thereby suppressing increases in electricity charges. The distributed power source and the vehicle power storage device can be operated efficiently.

[0014] This charging / discharging system will contribute to the environment (reducing carbon dioxide emissions) by providing a charging infrastructure for electric vehicles, which are expected to become increasingly popular in the future, while suppressing increases in electricity costs associated with system operation. Furthermore, the charging / discharging system is useful as a BCP (Business Continuity Plan) measure in the event of a power outage. Therefore, the introduction of charging / discharging systems by public and / or private organizations will be encouraged.

[0015] The charging / discharging system may include an electricity storage unit capable of discharging to the charging / discharging unit via the conversion circuit. The power storage unit may be configured by a plurality of secondary batteries connected in series and / or parallel, but is not limited to this configuration.

[0016] According to the charging / discharging system configured as described above, the power stored in the power storage unit can be output via the conversion circuit to assist the power used by the charging / discharging unit to charge the vehicle power storage device. For example, electricity from the inexpensive power grid at night can be stored in the power storage unit to assist the power used to charge the vehicle power storage device. This can reduce increases in electricity charges associated with the operation of the charging / discharging system. Furthermore, because the control unit controls the output of the conversion circuit so that the received power reaches a target value, it is possible to reliably prevent the power stored in the power storage unit from flowing back into the power grid.

[0017] In the charging / discharging system, the control unit may have a communication unit capable of communicating with the charging / discharging unit. The communication unit may be one that performs wireless communication, one that performs wired communication, or one that can perform both.

[0018] According to the charge / discharge system configured as described above, the distributed power source and / or the power storage unit and the vehicle power storage device connected to the charge / discharge unit can be operated in a coordinated manner. For example, if the conversion circuit and control unit are provided in a power conditioner (connected to a distributed power source and a storage unit) and the charging / discharging unit is provided in a charger / discharger (connected to a vehicle storage device), the distributed power source, storage unit, and vehicle storage device can be operated optimally depending on the time and situation by sharing information and issuing control instructions via the communication unit.

[0019] In the charging / discharging system, the charging / discharging unit may obtain or estimate a state of charge (SOC) of the vehicle power storage device. The charge / discharge unit may be capable of acquiring the SOC of the vehicle power storage device by communicating with the vehicle via a charge / discharge cable, but is not limited to this form.

[0020] The charging / discharging system configured as described above enables energy management that utilizes the power supply and demand adjustment capabilities of the vehicle (vehicle power storage device) connected to the charging / discharging unit. This improves the charging / discharging system's peak shaving capability, load leveling capability, and demand response (DR) achievement capability. Furthermore, the charging / discharging system can be used to build a virtual power plant (VPP).

[0021] In the charging / discharging system, the communication unit may transmit information including a state of the conversion circuit and information including a state of the charging / discharging unit to an information processing device. The information processing device may be a remote monitoring server, a customer data management server, or a blockchain system.

[0022] The charging / discharging system configured as described above makes it possible to remotely grasp the operating status and operation history of the conversion circuit and charging / discharging unit, allowing stakeholders in the charging / discharging system to optimally operate the distributed power source, energy storage unit, and vehicle energy storage device according to the time and situation.

[0023] In the charge / discharge system, the control unit may change the target value of the received power based on a predicted value of the amount of power generated by the distributed power source and a predicted value of power consumption by a demand facility. The demand facility may be an on-premise load whose power consumption is predictable (easy to predict).

[0024] With the charging / discharging system configured as described above, the flow of power from the power grid to the receiving point can be adjusted by changing the target value of the received power, and an energy management system (EMS) can be simply realized using a power conditioner, etc. By performing power supply and demand forecasts and demand adjustments using the power conditioner's control unit and communication unit, it is possible to support up-driving and down-driving at low cost without using a dedicated EMS controller.

[0025] The charging / discharging system may have a housing that houses the conversion circuit, the control unit, and the charging / discharging unit, and a charging / discharging cable may extend from the housing. The charging / discharging system may include a first converter circuit, a second converter circuit, and a third converter circuit connected to the conversion circuit. A distributed power source may be connected to the first converter circuit, the energy storage unit may be connected to the second converter circuit, and a charging / discharging cable may be connected to the third converter circuit. The housing may be a metal housing (a so-called panel), but is not limited to this form. The housing may have an openable / closable lid, or may have a wall separating a space housing the conversion circuit and control unit from a space housing the charge / discharge unit. Alternatively, the housing housing the conversion circuit and control unit and the housing housing the charge / discharge unit may be adjacently disposed and fixed.

[0026] The charge / discharge system having the above configuration can promote the sharing of parts, thereby saving space and reducing costs, compared to a system constructed with a power conditioner and a separate charger / discharger.

[0027] Hereinafter, embodiments will be described in detail with reference to the drawings.

[0028] First Embodiment The charge / discharge system for a distributed power source shown in Fig. 1 includes a power conditioner 20 connected to a solar power generation panel 4, and a charger / discharger 51 that charges a power storage device of a vehicle (hereinafter referred to as an "automobile") 3. The solar power generation panel 4 is an example of a distributed power source. The charger / discharger 51 is an example of a charge / discharge unit.

[0029] 1. Configuration and operation of power conditioner In addition to the solar power generation panel 4, a power storage unit 10 is connected to the power conditioner 20. The power storage unit 10 may be composed of a plurality of secondary batteries, for example, a plurality of lithium-ion batteries, connected in series and / or parallel. The power conditioner 20 is preferably a three-phase grid-connected power storage system that can supply power to a wide range of electrical loads. For example, space can be saved by using a so-called power conditioner with a storage battery that is integrally provided with the power storage unit 10.

[0030] The power conditioner 20 includes a first converter circuit 21, a second converter circuit 23, a bidirectional inverter circuit 22, and a control device 25.

[0031] The photovoltaic panel 4 is connected to the first converter circuit 21. The first converter circuit 21 is a DC / DC converter, and boosts and outputs the output voltage (direct current) of the photovoltaic panel 4. The first converter circuit 21 may be a boost chopper.

[0032] The power storage unit 10 is connected to the second converter circuit 23. The second converter circuit 23 is a bidirectional DC / DC converter, and discharges and charges the power storage unit 10. The second converter circuit 23 may be a bidirectional chopper.

[0033] The energy storage unit 10 can store surplus power from the solar power generation panel 4 and power from the power grid 1 that uses the grid power supply 2 as an AC power source via the second converter circuit 23. When the amount of power generated by the solar power generation panel 4 is insufficient, the energy storage unit 10 can discharge the power and make up for the shortage of power generation via the second converter circuit 23.

[0034] The bidirectional inverter circuit 22 is a bidirectional conversion circuit that selectively performs inverse conversion (inversion) to convert DC power to AC power and forward conversion (conversion) to convert AC power to DC power. The bidirectional inverter circuit 22 is connected to the power system 1. The bidirectional inverter circuit 22 is an example of a conversion circuit.

[0035] The power conditioner 20 has therein a current detection unit 26 and a voltage detection unit 27. The current detection unit 26 is, for example, a through-hole type Hall sensor, and detects the current flowing through the power line connecting the bidirectional inverter circuit 22 and the power grid 1. The voltage detection unit 27 detects the voltage of the power line connecting the bidirectional inverter circuit 22 and the power grid 1. The detected current and voltage are input to the control device 25. By providing the current detection unit 26 and the voltage detection unit 27, the power conditioner 20 can perform output control of the bidirectional inverter circuit 22 (constant received power control, variable received power control, etc.) even when an external measuring instrument 2b (described later) is not provided at the power receiving point 2a.

[0036] Based on the detected current and voltage, the control device 25 calculates the power (active power) Pinv flowing in and out of the power line connecting the power conditioner 20 and the power grid 1. Here, the power Pinv of the forward flow (power flow from the power grid 1 to the power conditioner 20) is expressed as a positive value, and the power Pinv of the reverse flow (power flow from the power conditioner 20 to the power grid 1) is expressed as a negative value. The control device 25 controls the output of the bidirectional inverter circuit 22 using the calculated power Pinv.

[0037] The control device 25 has a CPU (Central Processing Unit) 25a as a processor and a memory 25b as a storage unit. The memory 25b stores a program for predicting power supply and demand and a program for changing a target value for received power. The control device 25 is an example of a control unit.

[0038] As will be described later, the control device 25 controls the output of the bidirectional inverter circuit 22 so that the power received from the power grid 1 reaches a target value while the charger / discharger 51 is charging the power storage device of the vehicle 3. The power conditioner 20 adjusts the output power of the bidirectional inverter circuit 22 based on the input power from the solar power generation panel 4 and / or the power storage unit 10, while assisting the power for charging by the charger / discharger 51. This makes it possible to suppress an increase in power received from the power grid 1 due to charging the power storage device of the vehicle 3.

[0039] For public and private organizations considering the introduction of a charging and discharging system, it is undesirable for the system to operate and for the amount of power received from the power grid 1 to be increased in order to charge the power storage devices of the vehicles 3. Charging the vehicles 3 during normal times makes it possible to supply power from the vehicles 3 in emergencies, but it is undesirable for electricity bills to increase as vehicles 3 are frequently charged in preparation for emergencies that may occur at any time.

[0040] The control device 25 adjusts the output of the bidirectional inverter circuit 22 while assisting the power for charging by the charger / discharger 51, thereby suppressing such increases in electricity charges. This control function promotes the introduction of charge / discharge systems. For example, it promotes the introduction of charge / discharge systems by private companies that operate car sharing services.

[0041] A power line 29a branches off from the power line connecting the bidirectional inverter circuit 22 and the power system 1 (between the bidirectional inverter circuit 22 and the current detection unit 26) and extends to a switching circuit 24 (contact point A) inside the power conditioner 20. A contact point B of the switching circuit 24 is connected to the bidirectional inverter circuit 22 via a power line 29b.

[0042] The switching circuit 24 is connected to a three-phase specific load 4a including a power load such as an elevator, and a single-phase specific load (for example, an electric lamp) 4b via a transformer.

[0043] In the event of a power outage in the power grid 1, backup power is supplied to the specific loads 4a and 4b from at least one of the solar power generation panel 4, the power storage unit 10, and the charger / discharger 51. That is, power discharged from the power storage device of the automobile 3 is supplied to the specific loads 4a and 4b via the charger / discharger 51. Furthermore, by connecting the specific loads 4a and 4b to contact B of the switching circuit 24, power supplied from the solar power generation panel 4 and / or the power storage unit 10 is supplied to the specific loads 4a and 4b via the bidirectional inverter circuit 22 and the power line 29b. Such a charge / discharge system is useful as a BCP measure.

[0044] The power conditioner 20 has a communication board 28. The communication board 28 may be a network interface card (NIC). The communication board 28 is communicably connected to the control device 25 via a communication line (not shown). The communication board 28 is an example of a communication unit (first communication unit).

[0045] 2.Charger / Discharger Configuration and Operation The charger / discharger 51 has a communication board 73 that can communicate with the communication board 28 of the power conditioner 20 via the communication line L1 or by wireless communication. The communication board 73 (second communication unit) may be a network interface card (NIC). In the charge / discharge system, the communication board 28 of the power conditioner 20 may function as a parent device, and the communication board 73 of the charger / discharger 51 may function as a child device.

[0046] In an emergency such as a power outage, the charger / discharger 51 discharges the power storage device of the automobile 3. The built-in bidirectional conversion unit 60 converts DC power from the automobile 3 into AC power, which is supplied to the specific loads 4a and 4b via the power line 29d.

[0047] 2 , a plurality of chargers / dischargers (hereinafter referred to as "charge / discharge stands") 51 may be provided in the charge / discharge station 6. A power conditioner 20 (10) with a storage battery that can communicate with the charge / discharge stands 51 may be arranged adjacent to the charge / discharge station 6. Alternatively, the power conditioner 20 and / or the energy storage unit 10 may be arranged at a location away from the charge / discharge station 6.

[0048] The charging / discharging station 6 may be located in a public place such as a public car park, or alternatively, on the premises of a business or private individual. The charging / discharging station 6 may be a centralized type in which parking spaces S1 to S5 are arranged adjacent to each other as shown in Fig. 2, or a distributed type in which parking spaces are distributed (for example, arranged on different floors of a building) (not shown). In Fig. 2, a charging / discharging stand 51 is arranged in each parking space (S1, S2, ...), but this is not limited to this form. Although not shown, a single charging / discharging stand 51 may be installed in a single parking space.

[0049] As shown in Fig. 3, the charging / discharging stand 51 is a vertically long box-like shape, and has a display panel 53 and an operation unit 54 on a front wall 52 of the housing. The operation unit 54 includes input keys 54A (or a touch panel) and an execution key 54B. A side wall 55 of the housing holds a charging / discharging connector 57 and a charging / discharging cable 58. The charging / discharging stand 51 has a communication board 73 inside the housing.

[0050] 4 is a block diagram showing the electrical configuration of the charging / discharging stand 51. The charging / discharging stand 51 has a bidirectional conversion unit 60, a control unit 71, a storage unit 72, a communication board 73, a display panel 53, and an operation unit .

[0051] The communication board 73 may be used for communication with other charging / discharging stands 51 provided in the charging / discharging station 6. The communication may be wired communication or wireless communication.

[0052] One end of the bidirectional conversion unit 60 is connected to the AC terminal 56, and the other end is connected to the charge / discharge connector 57. The AC terminal 56 is connected to the power line 29d shown in Fig. 1. The bidirectional conversion unit 60 is a bidirectional conversion circuit that selectively performs forward conversion (conversion) to convert AC power to DC power, and inverse conversion (inversion) to convert DC power to AC power.

[0053] The control unit 71 controls the bidirectional conversion unit 60 by issuing commands to the bidirectional conversion unit 60 .

[0054] The charging / discharging connector 57 is inserted into the connection portion (inlet) of the automobile 3 shown in FIG.

[0055] The connectors are fitted together to electrically connect the bidirectional conversion unit 60 of the charging / discharging stand 51 to the power storage device (hereinafter referred to as the "vehicle battery") 5 of the automobile 3 shown in FIG. 2. The charging / discharging stand 51 charges or discharges the vehicle battery 5 using the bidirectional conversion unit 60. Specifically, the charging / discharging stand 51 charges the vehicle battery 5 by causing the bidirectional conversion unit 60 to perform a forward conversion operation, and discharges the vehicle battery 5 by causing it to perform a reverse conversion operation.

[0056] Furthermore, by fitting the connector, the control unit 71 shown in FIG. 4 is communicably connected to the automobile 3 via the communication line L2, and receives SOC information of the in-vehicle battery 5.

[0057] The control unit 71 calculates (estimates) the charge and discharge amounts of the in-vehicle battery 5 based on the output of the bidirectional conversion unit 60. In this way, the control unit 71 monitors fluctuations in the SOC of the in-vehicle battery 5 that accompany charging and discharging.

[0058] 3. Other configurations 1, a power line 29c branches off from the power line connecting the power conditioner 20 and the power grid 1 (between the power conditioner 20 and the power receiving point 2a of the power grid 1), and general loads 4c within the premises are connected to the power line 29c. The general loads 4c may include three-phase loads and single-phase loads.

[0059] The three-phase specific load 4a, the single-phase specific load 4b, and the three-phase or single-phase general load 4c are examples of demand facilities.

[0060] An external measuring instrument (external transducer) 2b is provided corresponding to a power receiving point 2a of the power system 1, detects the receiving current and system voltage, and calculates the received power (active power) Pgrid. The calculated received power Pgrid is input to the control device 25 of the power conditioner 20. The power Pgrid of the forward power flow (power flow from the power system 1 toward the premises) is expressed as a positive value, and the power Pgrid of the reverse power flow (power flow from the premises toward the power system 1) is expressed as a negative value.

[0061] 4. Constant receiving power control An example of the flow of power when the automobile 3 is charged by the charging / discharging station 51 will be described with reference to FIG. The switching circuit 24 inside the power conditioner 20 connects the specific loads 4a and 4b to the contact A. Before the charging / discharging stand 51 starts charging the vehicle 3, the power Pinv received from the power grid 1 is supplied to the specific loads 4a and 4b. At this time, the power Pinv is, for example, 600 watts (W), the forward flow AC current Iac_1 is, for example, 40 amperes, and the power is consumed by the specific loads 4a and 4b.

[0062] When the charging / discharging stand 51 starts charging the automobile 3, in order to maintain the power Pinv at a target value, the control device 25 instructs the power storage unit 10 to discharge a DC current Idc_1 and the bidirectional inverter circuit 22 to output an AC current Iac_2 (for example, 40 amperes). The control device 25 controls the output of the bidirectional inverter circuit 22 so that the power Pinv becomes a positive target value (for example, 600 W) (constant received power control).

[0063] With the received power Pinv maintained at 600 W, power is consumed by the specific loads 4a and 4b, and an AC current Iac_3 (e.g., 40 amperes) flows through the power line 29d. The charging / discharging stand 51 converts the AC power into DC power using the bidirectional conversion unit 60 and outputs a DC current Idc_2 (e.g., 12 amperes). In this way, the charging / discharging stand 51 charges the vehicle 3.

[0064] Such constant control of received power by the control device 25 allows charging of the vehicle 3 without excessively increasing the amount of power received from the power grid 1, thereby suppressing increases in electricity charges. Even during discharging from the power storage unit 10, the forward flow of power (600 W) from the power grid 1 continues, so that the power stored in the power storage unit can be reliably prevented from flowing backward to the power grid 1.

[0065] 5 shows an example in which power is supplied only from the power storage unit 10, but power for charging the automobile 3 may be supplied from the solar power generation panel 4, or power may be supplied from both the power storage unit 10 and the solar power generation panel 4. In either case, constant control of received power by the control device 25 can suppress an increase in electricity charges associated with operation of the charge / discharge system.

[0066] Instead of the received power Pinv, the control device 25 may perform constant received power control based on the received power Pgrid at the receiving point 2a of the power grid 1. Control based on the detected value of the external measuring device 2b tends to result in slightly increased control error compared to control based on the detected values ​​of the current detection unit 26 and voltage detection unit 27 inside the power conditioner 20, but it also allows for consideration and monitoring of power consumption by general loads 4c within the premises.

[0067] 5. Variable receiving power control As shown in Fig. 6, the communication board 28 of the power conditioner 20 obtains forecast data of the future (for example, the next day's) amount of power generation of the photovoltaic power generation panel 4 from the forecast data provider 7 and stores the data in the memory 25b of the control device 25. The forecast value of the amount of power generation of the photovoltaic power generation panel 4 can be obtained from the forecast value of the amount of solar radiation. The forecast value of the amount of solar radiation is obtained from meteorological information.

[0068] The control device 25 predicts future (e.g., the next day's) power consumption of the on-premises demand facilities 4a, 4b, and 4c and stores the prediction in memory 25b. The power consumption of the on-premises demand facilities 4a, 4b, and 4c can be predicted from past data, and for example, the power consumption data for the next day can be predicted by statistically processing the power consumption data for several days.

[0069] As described above, the communication board 28 of the power conditioner 20 functions as a parent device, and the communication board 73 of the charging / discharging stand 51 functions as a child device. This allows the control device 25 to sequentially acquire or calculate SOC information (dischargeable amount of electricity, chargeable amount of electricity) of the onboard battery 5 of the automobile 3 connected to the charging / discharging stand 51. From the SOC information, the control device 25 can grasp the power supply and demand adjustment capability of the onboard battery 5 of the automobile 3. The control device 25 also sequentially acquires or calculates SOC information of the power storage unit 10.

[0070] If discharge from vehicle 3 is scheduled for a certain time in the future (e.g., the next day), the control device 25 may lower the target value of the received power Pinv (or Pgrid) in the constant received power control while the time arrives and the vehicle 3 is discharging. If charging of the vehicle 3 is scheduled for a certain time in the future (e.g., the next day), the control device 25 may increase the target value of the received power Pinv (or Pgrid) in the constant received power control while the time arrives and the vehicle 3 is being charged.

[0071] By changing the target value of the received power in this way (variable control of received power), the flow of power from the power grid 1 to the power receiving point 2a can be adjusted, and an energy management system (EMS) can be realized with the power conditioner 20, the energy storage unit 10, the charging / discharging stand 51, and the on-board battery 5 of the automobile 3. By performing power supply and demand prediction and demand adjustment using the control device 25 and communication board 28 of the power conditioner 20, it becomes possible to support up DR and down DR at low cost without using a dedicated EMS controller.

[0072] This charging / discharging system allows cooperative operation of the solar power generation panel 4, the power storage unit 10, and the on-board battery 5 of the automobile 3 connected to the charging / discharging stand 51. By using the on-board battery 5 for demand adjustment in addition to the power storage unit 10, it is possible to flexibly respond to demand response commands, etc. By exchanging power between the power storage unit 10 and the on-board battery 5, it is possible to prevent the SOC of one of the batteries from increasing or decreasing excessively, thereby reducing the battery life.

[0073] In this way, the peak cutting capability, load leveling capability, or demand response achievement capability of the charge / discharge system can be improved without reducing the expected life of the power storage unit 10 and the in-vehicle battery 5. Furthermore, a VPP can be constructed using the charge / discharge system.

[0074] Second Embodiment A communication board 28 (see FIG. 1) provided in the power conditioner 20 and functioning as a parent device transmits information including the status of the power conditioner 20 (bidirectional inverter circuit 22) and information including the status of the charging / discharging stand 51 to an information processing device such as a remote monitoring server.

[0075] 7 is a diagram showing an overview of the remote monitoring system 100. The remote monitoring system 100 enables remote access to information relating to the energy storage elements and power supply-related devices included in the mega solar power generation system S, the thermal power generation system F, and the wind power generation system W. Similarly, the remote monitoring system 100 enables remote access to information relating to the power conditioner with storage battery 20(10) and the charging / discharging stand 51.

[0076] A power conditioner P and a storage battery system 101 are arranged in parallel in the power generation systems S, F, and W. The storage battery system 101 may be configured by arranging a plurality of containers C, each housing a storage module group L, in parallel. The container C also houses the power conditioner P. Alternatively, the storage module group L and the power conditioner P may be arranged inside a building (storage room).

[0077] In the remote monitoring system 100, a communication device is mounted on / connected to a storage battery system 101 or a power supply-related device in a system S, F, W, 20 (10), 51 to be monitored. The communication device may communicate with a battery management unit (BMU) provided in a storage module group L to receive information about the storage elements. The communication device may be a network interface card-type communication board 28, 73 (see FIG. 3). The remote monitoring system 100 includes the communication device, a server device 200 that collects information from the communication device, a client device 30 for viewing the collected information, and a network N that is a communication medium between the devices.

[0078] The server device 200 includes a web server function, and presents information obtained from communication devices installed in / connected to each device to be monitored in response to access from the client device 30.

[0079] The network N includes a public communication network N1, which is the so-called Internet, and a carrier network N2 that realizes wireless communication according to a predetermined mobile communication standard. The public communication network N1 includes a general optical line, and the network N includes a dedicated line to which the server device 2 is connected. The carrier network N2 includes a base station BS, and the client device 30 can communicate with the server device 200 from the base station BS via the network N. An access point AP is connected to the public communication network N1, and the client device 30 can communicate with the server device 200 from the access point AP via the network N.

[0080] The client device 30 may be a desktop or laptop personal computer, or may be a so-called smartphone or tablet communication terminal. The client device 30 includes a control unit, a storage unit, a communication unit, a display unit 33, and an operation unit 34. The storage unit stores a client program including a web browser that is read and executed by the control unit.

[0081] A user who logs in through a login screen displayed on the web browser of the client device 30 can access information provided by the server device 200 about the system in which the user is involved.

[0082] The remote monitoring system 100 makes it possible to remotely grasp the operating status and operation history of the power conditioner 20, the power storage unit 10, the charging / discharging stand 51, and the on-board battery 5 (see FIG. 2) in the charging / discharging system. It is also possible to access the communication board 23 of the power conditioner 20 and the communication board 73 of the charging / discharging stand 51 to change settings and give operation instructions. Stakeholders in the charging / discharging system can operate the solar power generation panel 4, the power storage unit 10, and the on-board battery 5 optimally depending on the time and situation.

[0083] <Third embodiment> The power conditioner 20 (10) with a storage battery, which is shown in FIG. 8 and has an integrated charge / discharge unit, has a housing that houses a bidirectional inverter circuit, a control device, and a charge / discharge unit, and a charge / discharge cable 58 extends from the housing.

[0084] 1, a first converter circuit 21 and a second converter circuit 23 are connected to a bidirectional inverter circuit 22 of a power conditioner 20. A charger / discharger 51 incorporating a bidirectional conversion unit 60 is provided separately from the power conditioner 20. In contrast, the power conditioner with storage battery 20 (10) shown in Fig. 8 is integrally provided with a charge / discharge stand (charge / discharge unit) 51. As shown in Fig. 9, an internal bidirectional inverter circuit 22 is connected to a first converter circuit 21 connected to the solar power generation panel 4, a second converter circuit 23 connected to the power storage unit 10, and a bidirectional conversion unit 60 as a third converter circuit connected to a charge / discharge cable 58. The bidirectional conversion unit 60 may be controlled by a control device 25 of the power conditioner 20. The control device 25 of the power conditioner 20 may be communicably connected to the automobile 3 and receive and monitor SOC information of the in-vehicle battery 5.

[0085] Such a charging / discharging system can promote the sharing of parts, thereby saving space and reducing costs, compared to a system (such as that shown in FIG. 1) constructed with a power conditioner 20 and a separate charging / discharging stand 51. For example, a single communication board may be used for both internal communication and external communication.

[0086] The present invention is not limited to the above-described embodiments, and suitable combinations of the above-described embodiments and the following embodiments are also included within the technical scope of the present invention.

[0087] (1) A charging and discharging system for a distributed power source that can be connected to a power grid, A conversion circuit; a control unit for controlling the conversion circuit; a charge / discharge unit connected to the conversion circuit and capable of charging the vehicle power storage device, the control unit has a communication unit capable of communicating with the charge / discharge unit, The communication unit transmits information including the state of the conversion circuit and information including the state of the charge / discharge unit to an information processing device. Charging and discharging system.

[0088] (2) The charging / discharging system according to (1), wherein the control unit or the charging / discharging unit acquires or estimates a state of charge of the vehicle power storage device.

[0089] (3) A charging and discharging system for a distributed power source that can be connected to a power grid, A conversion circuit; a control unit for controlling the conversion circuit; a charge / discharge unit connected to the conversion circuit and capable of charging the vehicle power storage device, The control unit changes the target value of the received power based on a predicted value of the amount of power generated by the distributed power source and a predicted value of power consumption by the demand facility. Charging and discharging system.

[0090] (4) A charging and discharging system for a distributed power source that can be connected to a power grid, A conversion circuit; a control unit for controlling the conversion circuit; a charge / discharge unit connected to the conversion circuit and capable of charging a vehicle power storage device; a housing that houses the conversion circuit, the control unit, and the charge / discharge unit; A charging / discharging cable extends from the housing. Charging and discharging system.

[0091] (5) A charging and discharging system for a distributed power source that can be connected to a power grid, A conversion circuit; a control unit for controlling the conversion circuit; a first converter circuit, a second converter circuit, and a third converter circuit connected to the conversion circuit; a distributed power source is connected to the first converter circuit; a power storage unit connected to the second converter circuit; A charge / discharge cable is connected to the third converter circuit. Charging and discharging system.

[0092] In the above embodiment, a system including a charge / discharge unit has been described, but the technical concept of the present invention can also be applied to a charging system that does not have a discharge function and uses a distributed power source and a charging unit. (6) A charging system for a distributed power source that can be connected to a power grid, A conversion circuit; a control unit for controlling the conversion circuit; a charging unit connected to the power system and the conversion circuit and capable of charging a vehicle power storage device, The control unit controls the output of the conversion circuit so that the power received from the power grid reaches a target value while the charging unit is charging the vehicle power storage device. Charging system.

[0093] (7) The charging system according to (6) above, further comprising a power storage unit capable of discharging to the charging unit via the conversion circuit. [Explanation of symbols]

[0094] 3. Automobiles (vehicles) 4a, 4b, 4c load (demand equipment) 10 Energy storage unit 20 Power Conditioner 22 Bidirectional inverter circuit (conversion circuit) 25 Control device (control unit) 28 Communication board (communication unit) 51 Charger / discharger (charge / discharge unit)

Claims

1. A charging / discharging system for a distributed power source that can be connected to a power grid, A conversion circuit; a control unit for controlling the conversion circuit; a charge / discharge unit connected to the power grid and the conversion circuit and capable of charging a vehicle power storage device, The control unit controls the output of the conversion circuit so that the power received from the power grid reaches a target value while the charging / discharging unit is charging the vehicle power storage device. Charging and discharging system.

2. The charging / discharging system according to claim 1 , further comprising an electricity storage unit capable of discharging to the charging / discharging unit via the conversion circuit.

3. The charging / discharging system according to claim 1 or 2, wherein the control unit has a communication unit capable of communicating with the charging / discharging unit.

4. The charging / discharging system according to claim 3 , wherein the charging / discharging unit acquires or estimates a state of charge of the vehicle power storage device.

5. The charging / discharging system according to claim 3 , wherein the communication unit transmits information including the state of the conversion circuit and information including the state of the charging / discharging unit to an information processing device.

6. The charging / discharging system according to any one of claims 1 to 5, wherein the control unit changes the target value of the received power based on a predicted value of the power generation amount of the distributed power source and a predicted value of the power consumption of the demand facility.

7. The charging / discharging system according to any one of claims 1 to 6, further comprising a housing that houses the conversion circuit, the control unit, and the charging / discharging unit, and a charging / discharging cable extending from the housing.

8. a first converter circuit, a second converter circuit, and a third converter circuit connected to the conversion circuit; a distributed power source is connected to the first converter circuit; the power storage unit is connected to the second converter circuit; The charging / discharging system according to any one of claims 1 to 7, wherein a charging / discharging cable is connected to the third converter circuit.

9. A control method for a charge / discharge system for a distributed power source that can be connected to a power grid, comprising: the charge / discharge system includes a conversion circuit, a control unit that controls the conversion circuit, and a charge / discharge unit that is connected to the power grid and the conversion circuit and is capable of charging a vehicle power storage device, The control unit controls the output of the conversion circuit so that the power received from the power grid becomes a target value while the charging / discharging unit is charging the vehicle power storage device. Control method.

10. A computer program for controlling a charging / discharging system for a distributed power source that can be connected to an electric power grid, the charge / discharge system includes a conversion circuit, a control unit that controls the conversion circuit, and a charge / discharge unit that is connected to the power grid and the conversion circuit and is capable of charging a vehicle power storage device, On the computer, Controlling the output of the conversion circuit so that the power received from the power grid reaches a target value while the charging / discharging unit is charging the vehicle power storage device A computer program that executes a process.

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