Server, power management method

Abstract

The present application relates to a kind of server, power management method.In the present application, first switching part (112) when first power grid (MG) is switched from independent operation to the linkage operation of second power grid (PG), from multiple power regulation resources (500) determine master and slave (S31), with the power of first power grid (MG) and the power of second power grid (PG) synchronously, implement master-slave control based on master and slave (S34) in the way, thereafter make first power grid (MG) and second power grid (PG) parallel (S37).First switching part (112) preferentially select the power regulation resource in multiple power regulation resources (500) as master (S31) from the connection point (501) of first power grid (MG) and second power grid (PG) near.

Description

Technical Field

[0001] This invention relates to a server and a power management method for managing multiple power regulation resources that can be electrically connected to the power grid. Background Technology

[0002] For example, a method is disclosed in Japanese Patent Application Publication No. 2020-028198.

[0003] The method described above is a way to implement supply and demand management of a microgrid using multiple power regulation resources (specifically, distributed power sources, loads, and induction motors with flywheels) that can be electrically connected to the microgrid. Summary of the Invention

[0004] In the method described in Japanese Patent Application Publication No. 2020-028198, under normal circumstances, the microgrid operates in conjunction with an external power grid (specifically, a large-scale commercial power system) to supply power to the microgrid. On the other hand, when the external power grid experiences a power outage, the microgrid switches to independent operation and adjusts the supply and demand balance of the microgrid by disconnecting loads connected to the microgrid.

[0005] When the external power grid recovers from a power outage, the microgrid returns to interlocked operation. However, when the microgrid switches from independent operation to interlocked operation, the power supply of the microgrid and the external power grid may not be synchronized. Therefore, when the microgrid is connected in parallel with the external power grid, the power supply of the microgrid sometimes becomes unstable. Japanese Patent Application Publication No. 2020-028198 did not address this issue.

[0006] This invention was made to solve the above-mentioned problems, and its purpose is to suppress the instability of the power grid when the power grid switches from independent operation to interlocked operation.

[0007] The server of this invention is configured to implement power management of a first power grid. The first power grid is configured to be able to connect in parallel with and disconnect from a second power grid. The server has a resource management unit and a first switching unit. The resource management unit manages multiple power regulation resources that can be electrically connected to the first power grid. When switching the first power grid from independent operation to operation in conjunction with the second power grid, the first switching unit determines the master and slave from the multiple power regulation resources, and after implementing master-slave control based on the master and slave in a manner that synchronizes the power of the first power grid with the power of the second power grid, connects the first power grid and the second power grid in parallel. The first switching unit is configured to preferentially select the power regulation resource closest to the connection point between the first power grid and the second power grid as the master.

[0008] Hereinafter, the connection point between the first power grid and the second power grid will be referred to as the "linkage point". The distance from the linkage point to the power regulation resources will be referred to as the "linkage point distance". The switching of the first power grid from independent operation to linked operation will be referred to as "linkage switching". The switching of the first power grid from linked operation to independent operation will be referred to as "independent switching".

[0009] In the aforementioned server, before the first power grid and the second power grid are connected in parallel (connected), master-slave control is implemented, and the power of the first power grid is synchronized with the power of the second power grid. Moreover, the aforementioned server preferentially selects the power regulation resource closest to the linkage point as the master.

[0010] The farther the power regulation resource is from the linkage point, the longer the power line from the linkage point to the power regulation resource. When matching the power of the first power grid with the power of the second power grid using a power regulation resource far from the linkage point, the increased inductance of the power line from the linkage point to the power regulation resource easily leads to a deviation between the power of the first and second power grids. Therefore, compared to using a power regulation resource closer to the linkage point as the master for master-slave control, using a power regulation resource closer to the linkage point as the master for master-slave control can achieve high-precision synchronization of the power of the first and second power grids.

[0011] After synchronizing the power supply of the first power grid with the power supply of the second power grid with high precision, the aforementioned server connects the first power grid and the second power grid in parallel. This prevents the power supply of the first power grid from becoming unstable when switching from independent operation to coordinated operation.

[0012] Furthermore, the number of master units in master-slave control can be one or more. In master-slave control, multiple master units can also cooperate to determine the frequency and voltage of the first power grid. The number of master units can be more than one and less than four. The number of slave units is greater than the number of master units. The number of slave units can be more than five, more than 30, or more than 100. In master-slave control, each slave unit can also operate according to the frequency and voltage determined by the master unit.

[0013] The aforementioned first switching unit can also be configured to select the host based on the communication and output performance of the power regulation resources.

[0014] The first switching unit mentioned above selects its master unit not only based on the distance to the linkage point (distance from the connection point) of the power regulation resources, but also considering the communication and output performance of the power regulation resources. Furthermore, the communication and output performance of the power regulation resources vary depending on the type of power regulation resource. In the master-slave control described above, the linkage point distance, communication performance, and output performance of the master unit affect the synchronization accuracy. There is a tendency that the shorter the linkage point distance of the master unit, the higher the synchronization accuracy. There is also a tendency that the higher the communication performance of the master unit, the higher the synchronization accuracy. And there is a tendency that the higher the output performance of the master unit, the higher the synchronization accuracy. Based on the above structure, selecting an appropriate master unit according to the situation during linkage switching easily improves the synchronization accuracy.

[0015] The aforementioned first switching unit can also be configured to remove power regulation resources with communication speeds lower than a first threshold and power regulation resources with maximum output power lower than a second threshold from the power regulation resources capable of responding to synchronization commands, and select the power regulation resource closest to the connection point from the remaining power regulation resources as the host.

[0016] In the above structure, power regulation resources with excessively low communication speed and excessively low maximum output power are removed from the candidate master. Then, the power regulation resource with sufficiently high communication speed and maximum output power, and the shortest linkage distance, is selected as the master. By using such a selected master to perform master-slave control, the above synchronization can be easily implemented with high precision.

[0017] The aforementioned power regulation resources can also include electric vehicles. Utilizing electric vehicles makes it easy to ensure sufficient power regulation resources. Because electric vehicles move, the distance between their linkage points changes. By implementing master-slave control with the electric vehicle connected to the nearest EVSE (Electric Vehicle Supply Equipment) as the master, the aforementioned synchronization can be implemented with high precision.

[0018] Furthermore, electric vehicles are vehicles configured to operate using electricity supplied from an onboard energy storage device. Electric vehicles include BEVs (Battery Electric Vehicles) and PHEVs (Plug-in Hybrid Electric Vehicles), as well as FCEVs (Fuel Cell Vehicles) and range-extended EVs. The energy storage device only needs to be configured to store electricity, and the storage method is arbitrary. The energy storage device can directly store electrical energy or convert it into other forms of energy (e.g., liquid or gaseous fuels as energy sources) for storage. Examples of energy storage devices include secondary batteries, fuel cells, and PtG (Power to Gas) devices.

[0019] The aforementioned multiple power regulation resources may also include stationary energy storage devices. The aforementioned first switching unit may also be configured to, in the case of an electric vehicle as the host, request a reduction in demand from the user of one or more of the multiple power regulation resources before implementing master-slave control.

[0020] Electric vehicles tend to have smaller capacity (kWh) compared to stationary energy storage devices. When the main unit's capacity is insufficient relative to the demand of the primary power grid, it may be impossible to stabilize the power supply of the primary power grid through master-slave control. Therefore, in the above structure, when the main unit is an electric vehicle, a request for a reduction in the demand of the primary power grid is made to one or more users of the power regulation resource before implementing master-slave control. By reducing the demand of the primary power grid according to this request, it is possible to suppress the insufficiency of the main unit's capacity relative to the demand of the primary power grid.

[0021] Furthermore, the aforementioned requests can be sent to the EMS (Energy Management System) or to the user terminal of the power regulation resource. The user terminal of the power regulation resource can also be pre-registered with the user of the power regulation resource on the server. The user terminal of the power regulation resource can be a terminal installed within the power regulation resource or a portable terminal carried by the user.

[0022] The aforementioned electric vehicles can also be fuel cell vehicles. By utilizing environmentally friendly fuel cell vehicles, it is easy to increase the proportion of clean energy in the primary power grid.

[0023] The server may also have a second switching unit. When switching the first power grid from linked operation to independent operation, the second switching unit determines the master and slave from multiple power regulation resources. The second switching unit is configured to preferentially select the power regulation resource with the larger capacity among the multiple power regulation resources as the master.

[0024] In the above structure, during independent switching, a power regulation resource with a large capacity is preferentially selected as the master. By implementing the master-slave control described above through a large-capacity master, the power of the first power grid can be easily stabilized. According to the above structure, the power of the first power grid can be easily stabilized during independent operation.

[0025] The aforementioned first switching unit can also be configured to determine the timing for switching the first power grid from independent operation to interlocked operation based on the regulating capacity of the first power grid when it operates independently.

[0026] From an electricity cost perspective, independent operation is more advantageous than coordinated operation. On the other hand, when the regulation capacity of the primary power grid (including regulation capacity based on multiple power regulation resources) is insufficient, the power quality of the primary power grid is prone to deterioration, making it difficult to maintain independent operation within the primary power grid. The aforementioned server determines the timing of coordinated switching based on the regulation capacity of the primary power grid, thus facilitating coordinated switching at appropriate timing.

[0027] The aforementioned first power grid can also be a microgrid. The aforementioned second power grid can also be a commercial power system provided by a power company. Each of the multiple power regulation resources can include a power conversion circuit. In the aforementioned master-slave control, the master unit electrically connected to the first power grid can implement voltage control through the power conversion circuit, and the slave unit electrically connected to the first power grid can implement current control through the power conversion circuit.

[0028] Based on the above structure, the microgrid can be easily and appropriately operated via a server. Furthermore, through master-based voltage control and slave-based current control, the aforementioned master-slave control-based synchronization during linkage switching can be easily and appropriately implemented.

[0029] The power management method of the present invention is a method for implementing power management of a first power grid, comprising the following steps: when switching the first power grid from independent operation to operation in conjunction with a second power grid, determining a master and slave device from multiple power regulation resources that can be electrically connected to the first power grid; implementing master-slave control based on the master and slave device in a manner that synchronizes the power of the first power grid with the power of the second power grid; and, after implementing synchronization based on master-slave control, connecting the first power grid and the second power grid in parallel. In determining the master and slave device, the power regulation resource closest to the connection point between the first and second power grids is preferentially selected as the master device.

[0030] In the aforementioned power management method, similar to the aforementioned server, synchronization is performed with high precision via the master-slave control before the coordinated switching. This helps to suppress instability in the primary power grid caused by the coordinated switching.

[0031] The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the invention, which is understood in conjunction with the accompanying drawings. Attached Figure Description

[0032] Figure 1 This is a diagram showing a schematic structure of a power system according to an embodiment of the present invention.

[0033] Figure 2 This is a functional block diagram illustrating the constituent elements of a server according to an embodiment of the present invention.

[0034] Figure 3 It means in Figure 1The flowchart shown illustrates the power regulation and control process executed by the server during the coordinated operation of the microgrid.

[0035] Figure 4 It means Figure 1 The diagram shows a first example of the configuration of power regulation resources around the receiving substation (connection point).

[0036] Figure 5 This is a diagram showing the priority order of host selection during independent switching in the power management method according to an embodiment of the present invention.

[0037] Figure 6 This indicates that in the power management method of the embodiments of the present invention Figure 1 The flowchart shown illustrates the power regulation and control performed by the server during the independent operation of a microgrid.

[0038] Figure 7 This is a flowchart illustrating the linkage switching process performed by the server in the power management method according to an embodiment of the present invention.

[0039] Figure 8 This diagram illustrates the first example of the priority order in host selection during linkage switching in the power management method according to an embodiment of the present invention.

[0040] Figure 9 It means Figure 1 The diagram shows a second example of the configuration of power regulation resources around the receiving substation (connection point).

[0041] Figure 10 This is a diagram illustrating a second example of the priority order in host selection during linkage switching in the power management method according to an embodiment of the present invention.

[0042] Figure 11 It means Figure 8 The diagram shows a variation of the priority order in host selection during linkage switching.

[0043] Figure 12 It means Figure 6 A diagram showing a variation of the processing.

[0044] Figure 13 It means Figure 7 A diagram showing a variation of the processing. Detailed Implementation

[0045] Embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same or corresponding parts are labeled with the same symbols, and their descriptions will not be repeated. Hereinafter, the Energy Management System will be referred to as "EMS". Furthermore, Distributed Energy Resource will be referred to as "DER". Additionally, the Electronic Control Unit installed in a vehicle will be referred to as "ECU".

[0046] Figure 1 This is a diagram illustrating the general structure of a power system according to an embodiment of the present invention. (Refer to...) Figure 1 Power system 1 includes power system PG, microgrid MG, server 100, 200, DER group 500, and receiving substation equipment 501.

[0047] Server 100 is a computer that manages the supply and demand of a microgrid MG. Server 100 is the manager of the microgrid MG. Server 100 corresponds to a CEMS (Community EMS) server. A microgrid MG is a power grid that supplies electricity to a city (e.g., a smart city). The power lines used in the microgrid MG to network multiple DERs can also be self-operated power lines. The microgrid MG is configured to be able to connect in parallel and disconnect from the power system PG. The microgrid MG corresponds to an example of the "first power grid" of the present invention.

[0048] Server 200 is a computer that manages the supply and demand of a power system PG. A power system PG is a power grid constructed from power plants and transmission and distribution equipment (not shown). A power company, corresponding to a typical power transmission and distribution enterprise, maintains and manages the power system PG (commercial power system). The power company is the manager of the power system PG. Server 200 belongs to the power company. In this embodiment, the power company and the power system PG are respectively equivalent to an example of the "power enterprise" and "second power grid" of the present invention.

[0049] The receiving transformer 501 is located at the connection point (power receiving point) of the microgrid MG and is configured to switch the parallel (connection) / disconnection (breakdown) of the power system PG and the microgrid MG. The receiving transformer 501 is located at the connection point between the microgrid MG and the power system PG.

[0050] When operating in a connected state between the microgrid MG and the power system PG, the receiving transformer 501 receives AC power from the power system PG, steps down the received power, and supplies it to the microgrid MG. When operating independently with the microgrid MG disconnected from the power system PG, no power supply from the power system PG to the microgrid MG is implemented. The receiving transformer 501 is configured to include switching devices (e.g., sectionalizing switches, circuit breakers, disconnectors, and load switches) on the high-voltage side (primary side), a transformer, protective relays, measuring equipment, and control devices. The server 100 is configured to receive information related to the microgrid MG (e.g., power waveforms) from the receiving transformer 501 and instruct the receiving transformer 501 to connect / disconnect.

[0051] Server 100 is configured to communicate with each of server 200 and DER group 500. The communication protocol may be OpenADR. DER group 500 contains multiple DERs that can be electrically connected to the microgrid MG. Server 100 is configured to manage the multiple DERs contained in DER group 500. Server 100 can also implement DR (demand response) for DER group 500 when requesting supply and demand regulation of the power system PG from server 200. Furthermore, server 100 can also implement DR for DER group 500 based on requests from the supply and demand regulation market. Additionally, server 100 can also implement DR for DER group 500 for the purpose of implementing supply and demand regulation of the microgrid MG.

[0052] The multiple DERs contained in DER group 500 are electrically interconnected via microgrid MG. DER group 500 includes EVSE (Electric Vehicle Supply Equipment) 20, residential 30, commercial facility 40, factory 50, ESS (Energy Storage System) 60, FCS (Fuel Cell System) 71, generator 80, and natural variable power source 90. Each of these can function as a DER.

[0053] DER group 500 also includes BEV (Electric Vehicle) 11A, 11B and FCEV (Fuel Cell Vehicle) 12A, 12B. EVSE20 functions as a DER when electrically connected to a vehicle (e.g., BEV or FCEV). For example, the charging connector of EVSE20 is inserted into the vehicle's inlet, thereby electrically connecting EVSE20 to the vehicle. BEV11A, 11B and FCEV12A, 12B each correspond to an example of the "electric vehicle" of this invention.

[0054] exist Figure 1In this diagram, two BEVs and two FCEVs are shown, but the number of vehicles included in DER Group 500 is arbitrary, ranging from 10 to 100 or more. DER Group 500 can include privately owned vehicles (POVs) or MaaS (Mobility as a Service) vehicles. MaaS vehicles are managed by MaaS operators. Furthermore, the number of EVSE20, residential 30, commercial facilities 40, factory 50, ESS60, FCS70, generator 80, and naturally aspirated power sources 90 included in DER Group 500 is also arbitrary.

[0055] BEV11A and 11B each have an ECU10a and a communication device C1. The ECU10a is configured to control onboard equipment. BEV11A and 11B each communicate wirelessly with server 100 via communication device C1. Furthermore, BEV11A and BEV11B each have an energy storage device B11 and an energy storage device B12, respectively. The capacity (kWh) and maximum output power (kW) of energy storage device B12 are smaller than those of energy storage device B11. The electricity stored in each energy storage device B11 and B12 is used to drive the BEV's drive motor (not shown) and is consumed by equipment mounted on the BEV.

[0056] FCEV12A and 12B each have an ECU10b, a power generation unit H2, and an energy storage unit B2. The ECU10b is configured to control onboard equipment. The power generation unit H2 includes a hydrogen tank for storing hydrogen and a fuel cell (neither shown) that generates electricity through the chemical reaction of hydrogen and oxygen. The fuel cell uses hydrogen supplied from the hydrogen tank to generate electricity. The electricity generated by the power generation unit H2 is used to drive the FCEV's drive motor (not shown), consumed by equipment mounted on the FCEV, and stored in the energy storage unit B2. FCEV users can refill hydrogen at hydrogen stations (not shown) located in cities. Furthermore, FCEV12A and FCEV12B each have a communication device C21 and a communication device C22, respectively. FCEV12A communicates wirelessly with server 100 via communication device C21. FCEV12B communicates wirelessly with server 100 via communication device C22. The communication speed of communication device C22 is lower than that of communication device C21.

[0057] DER Group 500 includes multiple EVSE20s (e.g., charging infrastructure maintained in cities). EVSE20s are public EVSEs that vehicle users can use by implementing prescribed certifications. Certification can be done via charging card or communication-based certification (e.g., Plug and Charge).

[0058] DER group 500 comprises multiple residences 30 (e.g., homes of people living in cities). Residences 30 contain various household electrical appliances (e.g., lighting fixtures, air conditioning equipment, cooking appliances, information equipment, televisions, refrigerators, and washing machines). Furthermore, residences 30 may also have at least one of the following: a power supply (e.g., a home electric energy system), a natural variable power source (e.g., rooftop solar panels), an energy storage and power system (ESS), a combined heat and power system (FCS), or a combined heat and power system (e.g., a water heater or heat pump water heater that uses heat generated from its own electricity generation). Energy supply and demand in residences 30 are managed, for example, by a HEMS (Home EMS) not shown. The microgrid MG and each residence 30 are electrically connected. In this embodiment, server 100 and each residence 30 communicate via HEMS.

[0059] Commercial facility 40 includes, for example, office buildings and shops. Examples of shops include department stores, shopping malls, supermarkets, or convenience stores. The energy supply and demand in the various facilities included in commercial facility 40 are managed, for example, by a BEMS (Building EMS) not shown. The BEMS can also manage the energy supply and demand of each facility separately, or it can aggregate and manage the energy supply and demand of multiple facilities. The various facilities included in commercial facility 40 and the microgrid MG are connected in a power-receiving manner. In this embodiment, server 100 communicates with commercial facility 40 via BEMS.

[0060] Factory 50 may be, for example, an automobile manufacturing plant or other types of factory. Factory 50 includes, for example, production lines and a centralized heat source for air conditioning. Furthermore, factory 50 may also have at least one of the following: a natural variable power source (e.g., solar or wind power generation equipment), an EVSE, an ESS, an FCS, a generator (e.g., a gas turbine generator or a diesel generator), or a combined heat and power system. Energy supply and demand in factory 50 are managed, for example, by a FEMS (Factory EMS) not shown. The microgrid MG and factory 50 are electrically connected. In this embodiment, server 100 and factory 50 communicate via FEMS.

[0061] The ESS60 is a stationary energy storage device configured to charge and discharge to a microgrid MG. Examples of suitable energy storage devices for the ESS60 include lithium-ion batteries, lead-acid batteries, nickel-metal hydride batteries, redox flow batteries, and NAS (sodium-sulfur) batteries. Surplus electricity generated by the natural variable power source 90 can also be stored in the ESS60.

[0062] FCS70 comprises a stationary fuel cell that generates electricity through the chemical reaction of hydrogen and oxygen. FCS70 is connected to a hydrogen tank 71, which is connected to a hydrogen generation device 72. FCS70 is configured to generate electricity using hydrogen supplied from hydrogen tank 71 and to supply the generated electricity to the microgrid MG. The hydrogen generation device 72 generates hydrogen and supplies the generated hydrogen to hydrogen tank 71. Any method can be used for hydrogen generation. For example, known methods such as by-product hydrogen generation, water splitting, fossil fuel modification, biomass modification, or IS (iodine / sulfur) processes can be used in hydrogen generation device 72. Hydrogen generation device 72 can also generate hydrogen using electricity supplied from the microgrid MG or surplus electricity generated by the variable power source 90. Server 100 can also control hydrogen generation device 72 to ensure that the remaining hydrogen level in hydrogen tank 71 is not lower than a specified value.

[0063] Generator 80 is a stationary generator that uses fossil fuels to generate electricity. Generator 80 can also be, for example, a gas turbine generator or a diesel generator. Generator 80 can be used as an emergency power source.

[0064] Naturally variable power source 90 is a power source whose output varies according to weather conditions and outputs the generated electricity to a microgrid MG. The electricity generated by the naturally variable power source 90 corresponds to variable renewable energy (VRE). The naturally variable power source 90 includes, for example, solar power generation equipment and wind power generation equipment.

[0065] Server 100 includes a processor 110, a storage device 120, and a communication device 130. The processor 110 may be a CPU (Central Processing Unit). The storage device 120 is configured to store various types of information. In addition to the program executed by the processor 110, the storage device 120 also stores information used in the program (e.g., mappings, mathematical formulas, and various parameters). The communication device 130 includes various communication I / F (interfaces). Server 100 is configured to communicate with the outside world via the communication device 130.

[0066] Server 100 controls DER group 500 connected to the microgrid MG, enabling DER group 500 to function as a VPP (Virtual Power Plant). More specifically, server 100 remotely and comprehensively controls DER group 500 using IoT (Internet of Things) energy management technology, thereby enabling it to function like a power plant. Each DER included in DER group 500 corresponds to an example of the "power regulation resource" of this invention.

[0067] Figure 2 This is a functional block diagram representing the constituent elements of server 100. (Refer to...) Figure 1 and Figure 2Server 100 includes a first operation unit 111, a first switching unit 112, a second operation unit 113, a second switching unit 114, and an information management unit 117. For example, through... Figure 1 The processor 110 shown and the program in the storage device 120 executed by the processor 110 implement the above-described components. However, this is not a limitation; these components may also be embodied in dedicated hardware (electronic circuitry). The server 100 of this embodiment corresponds to an example of the "server" of the present invention.

[0068] Server 100 is configured to communicate with portable terminal 10 and DER via communication device 130.

[0069] Each DER included in DER group 500 has a user-held portable terminal 10. Figure 2 In this embodiment, only one portable terminal 10 is shown, which is held by each DER user. In this embodiment, the portable terminal 10 is a smartphone with a touch panel display. However, it is not limited to this; any portable terminal can be used as the portable terminal 10, including tablets, wearable devices (such as smartwatches), or electronic keys. A specified application software (hereinafter referred to as "application") is installed on the portable terminal 10, and the portable terminal 10 is configured to exchange information with the server 100 through this application.

[0070] The information management unit 117 manages information about each user registered on server 100 (hereinafter also referred to as "user information"), information about each vehicle registered on server 100 (hereinafter also referred to as "vehicle information"), and information about each fixed DER registered on server 100 (hereinafter also referred to as "resource information"). User information, vehicle information, and resource information are distinguished by identification information (ID) for each user, each vehicle, and each DER, respectively, and stored in storage device 120. In this embodiment, the information management unit 117 functions as the "resource management unit" of the present invention.

[0071] Each vehicle registered in server 100 can function as a DER (Dedicated Vehicle) by connecting to EVSE20. Server 100 remotely operates the vehicles connected to EVSE20 via wireless communication, thereby enabling the vehicles to function as DERs. Vehicle information includes vehicle specifications (e.g., battery capacity and charge / discharge performance), vehicle location, and remaining battery charge (e.g., State of Charge). Vehicle location and status (e.g., SOC) are acquired by various sensors mounted on each vehicle and transmitted from each vehicle to server 100. Each vehicle can also transmit the latest vehicle location and status sequentially at predetermined periods, or the stored data (vehicle location and status) can be transmitted centrally at predetermined times (e.g., when driving ends or when the charging connector is connected).

[0072] Server 100 registers EVSE20, residential 30, commercial facility 40, factory 50, ESS60, FCS70, generator 80, and natural variable power source 90 as fixed DERs. Resource information includes the location, status, and specifications (e.g., maximum output power, capacity, and communication speed) of each fixed DER. For example, the status of EVSE20 includes whether or not a vehicle is connected. Furthermore, the status of EVSE20 connected to a BEV includes the status of that BEV (e.g., ECU operating / stop status, battery state of charge (SOC), and battery charge / discharge power). Additionally, the status of EVSE20 connected to an FCEV includes the status of that FCEV (e.g., ECU operating / stop status, remaining hydrogen in the generator, generator output power and surplus power, battery state of charge (SOC), and battery charge / discharge power). The statuses of residential 30, commercial facility 40, and factory 50 each include power consumption. The status of ESS60 includes the operating / stop status of the control system, SOC, and battery charge / discharge power. The states of FCS70 and generator 80 each include the operating / stop status of the control system, the generated power, and the remaining generating capacity. The state of FCS70 also includes the remaining hydrogen level in hydrogen tank 71. The state of natural variable power source 90 includes the generated power. Server 100 can obtain resource information through communication with each fixed DER.

[0073] The user information includes the communication address of the portable terminal 10 held by the user, the vehicle ID of the vehicle belonging to the user, the resource ID of the fixed DER belonging to the user, electricity charges, and incentive information (e.g., incentive amount received).

[0074] Each user registered on server 100 enters into a contract with the administrator of the microgrid MG (hereinafter referred to as the "MG administrator") to use the electricity supplied by the microgrid MG. According to this contract, the user (demander) who uses the electricity supplied from the microgrid MG is obligated to pay the stipulated electricity fee to the MG administrator. On the other hand, DER users who have regulated the electricity supply to the microgrid MG at the request of the MG administrator (e.g., DR) are entitled to receive incentives predetermined in the contract from the MG administrator. Information Management Department 117 manages the incentives given to DER users who have regulated the electricity supply to the microgrid MG. The incentives can be ordinary currency or virtual currency that can only be used within the city.

[0075] The DERs included in DER group 500 are roughly divided into power generation DERs, energy storage DERs, and load DERs.

[0076] In a power generation DER, a generator uses natural energy (e.g., solar or wind power) or fuel (e.g., light oil, natural gas, or hydrogen) to generate electricity, which is then output to the microgrid MG via a power conversion circuit. In a storage-type DER, power exchange between the storage device and the microgrid MG is performed through a power conversion circuit. The power conversion circuit in each DER operates according to control signals from server 100 and performs the prescribed power conversion. In this embodiment, the power conversion circuit includes an inverter and a PLL. Furthermore, the power conversion circuit may also include a relay for switching the connection / disconnection of the DER and the microgrid MG.

[0077] For example, in Figure 1 In the DER group 500 shown, ESS60 functions as a storage-type DER. Additionally, FCS70, generator 80, and natural variable power source 90 each function as a generating DER. The power output of the natural variable power source 90 is determined in principle by weather conditions, but its output can be limited.

[0078] BEV (e.g.) Figure 1 The BEVs shown (11A and 11B) function as energy-storage DERs. BEVs function as energy-storage DERs by implementing the charging and discharging of energy storage devices connected to the microgrid (MG). FCEVs (e.g.) Figure 1The FCEV12A and 12B shown function as a power generation DER. The FCEV functions as a power generation DER by outputting electricity generated by the power generation device to the microgrid MG. Furthermore, the FCEV can also be configured to function as an energy storage DER. If the capacity and charging / discharging performance of the energy storage device are sufficient, the FCEV can also function as an energy storage DER. The power conversion circuit can be installed in the vehicle (e.g., BEV and FCEV) or in the EVSE20. For example, DC power can be output from the vehicle to the DC-mode EVSE20, and DC / AC conversion is performed by the inverter built into the EVSE20. Furthermore, the on-board inverter performs DC / AC conversion on the power discharged from the energy storage device in the vehicle, and the converted AC power is output from the vehicle to the AC-mode EVSE.

[0079] Although Figure 2 While not explicitly stated, electrical equipment consuming power from the microgrid MG can also function as a load-type DER. The greater the electrical load of the equipment connected to the microgrid MG, the greater the power consumption of the microgrid MG. For example, Figure 1 The demanders of the residential buildings 30, commercial facilities 40, and factories 50 shown can regulate the supply and demand of the microgrid MG by adjusting the power load of electrical equipment.

[0080] In server 100, first operating unit 111 controls the DER, which functions as a regulating force for the microgrid MG, during the coordinated operation of the microgrid MG. Hereinafter, the DER, which functions as a regulating force for the microgrid MG, will be referred to as the "regulating force DER". More specifically, first operating unit 111 implements current control of the microgrid MG through the regulating force DER during the coordinated operation of the microgrid MG. The regulating force DER may, for example, incorporate a power conversion circuit including an inverter and a PLL (Phase Locked Loop). First operating unit 111 may also use at least one of ESS60, FCS70, and generator 80, which are always connected to the microgrid MG, as the aforementioned regulating force DER. Furthermore, first operating unit 111 may also use at least one of residential 30, commercial facility 40, factory 50, and EVSE20 (more specifically, EVSE20 connected to a vehicle) as the aforementioned regulating force DER by implementing DR.

[0081] In this embodiment, the first operation unit 111 uses the PLL of the regulating force DER to detect the amplitude and phase of the voltage waveform of the power system PG, and controls the inverter of the regulating force DER in a way that synchronizes the power of the microgrid MG with the power of the power system PG. The first operation unit 111 controls the AC current through the inverter of the regulating force DER, feeds back the current detection value, and at the same time makes the current flowing through the microgrid MG follow the target value. The first operation unit 111 can also divide the current flowing through the microgrid MG into an effective current component and an ineffective current component, and control the output voltage of the inverter of the regulating force DER in a way that the effective current component and the ineffective current component are close to the target value respectively.

[0082] The first switching unit 112 is configured to, during the linkage switching of the microgrid MG (i.e., when switching the microgrid MG from independent operation to linkage operation with the power system PG), determine the master and slave units from the DER group 500, and after implementing master-slave control based on the master and slave units in a manner that synchronizes the power of the microgrid MG with the power of the power system PG, connect the microgrid MG and the power system PG in parallel. The first switching unit 112 executes the aforementioned master-slave control in a manner that synchronizes the power of the microgrid MG with the power of the power system PG by sending synchronization commands to the master and slave units respectively.

[0083] In this embodiment, the first switching unit 112 selects a master unit from among the ESS60, FCS70, and EVSE20 (more specifically, the EVSE20 connected to the vehicle) located within a predetermined distance from the linkage point (receiving substation 501), according to a predetermined priority order. Details will be described later. The first switching unit 112 is configured to preferentially select the DER closest to the linkage point (receiving substation 501) as the master unit (see [reference]). Figure 8 However, the first switching unit 112 removes DERs that cannot respond to synchronization commands (e.g., DERs whose control system startup does not match the synchronization command) from the master candidate. Furthermore, the first switching unit 112 also removes DERs from the master candidate whose communication performance or output performance is insufficient in at least one aspect. The first switching unit 112 designates all DERs from the master candidate (those not removed) that were not selected as masters (i.e., DERs with a priority of second place or lower) as slaves. Additionally, if there are DERs outside the master candidate that can respond to synchronization commands, then those DERs outside the master candidate can also be designated as slaves.

[0084] In the master-slave control based on the first switching unit 112, the master unit, electrically connected to the microgrid MG, performs voltage control through a power conversion circuit (including an inverter), and each slave unit, also electrically connected to the microgrid MG, performs current control through a power conversion circuit (including an inverter). The master unit operates for voltage control. The voltage control can also be CVCF (Constant Voltage Constant Frequency) control. The first switching unit 112 controls the master unit by outputting AC power with a constant voltage and constant frequency from the master unit, thereby determining the frequency and voltage of the microgrid MG. Each slave unit operates for current control according to the frequency and voltage determined by the master unit.

[0085] The second switching unit 114 is configured to determine the master and slave units from the DER group 500 during independent switching of the microgrid MG (i.e., when switching the microgrid MG from interlocked operation to independent operation). In this embodiment, the second switching unit 114 selects a master unit from the ESS60, FCS70, and EVSE20 (more specifically, the EVSE20 connected to the vehicle) located within a predetermined distance from the interlocking point (receiving substation 501) according to a predetermined priority order. The second switching unit 114 preferentially selects the DER with the largest capacity from the DER group 500 as the master unit (see reference). Figure 5 (Details will be described later.) However, the second switching unit 114 removes DERs that cannot respond to the adjustment commands described later (e.g., DERs where the start-up of the control system does not match the adjustment commands) from the master candidate. The second switching unit 114 then makes all DERs that were not selected as master (i.e., DERs with a priority of second or lower) from the master candidate (DERs that were not removed) slaves. Furthermore, if there are DERs that can respond to the adjustment commands other than the master candidate, then DERs other than the master candidate may also be made slaves.

[0086] The second operation unit 113 controls the regulating force DER during the independent operation of the microgrid MG. More specifically, the second operation unit 113 performs master-slave control based on the master and slave units determined by the second switching unit 114 during the independent operation of the microgrid MG. For example, the second operation unit 113 performs the aforementioned master-slave control in a manner that stabilizes the power supply of the microgrid MG by sending regulation commands to the master and slave units respectively. In this master-slave control, similar to the master-slave control (for synchronization) based on the first switching unit 112, the master unit electrically connected to the microgrid MG implements voltage control through a power conversion circuit, and each slave unit electrically connected to the microgrid MG implements current control through a power conversion circuit. The master unit operates, for example, for CVCF control. Each slave unit operates for current control according to the frequency and voltage determined by the master unit.

[0087] The second operation unit 113 can also change at least one of the master and slave units during the independent operation of the microgrid MG. For example, the second operation unit 113 can also change at least one of the master and slave units before at least one of them becomes unable to respond to adjustment commands. Furthermore, the second operation unit 113 can also increase or decrease the number of slave units as needed during the independent operation of the microgrid MG. For example, the second operation unit 113 can also add slave units via a DR (Digital Reduction Unit).

[0088] Figure 3 This is a flowchart illustrating the power regulation and control performed by server 100 during the coordinated operation of the microgrid MG. (Refer to...) Figure 1 and Figure 2 as well as Figure 3 In step (hereinafter referred to as "S") 11, the second switching unit 114 determines whether an abnormality such as a power outage has occurred in the power system PG (external power grid). If the power system PG is normal (no in S11), the second switching unit 114 moves the processing to S12 in order to continue the linkage operation.

[0089] In S12, the first operation unit 111 operates the regulating force DER for current control, in a manner that synchronizes the power of the microgrid MG with the power system PG (external grid). The first operation unit 111 regulates the current of the microgrid MG through the regulating force DER (furthermore, to balance the supply and demand of the microgrid MG). During the coordinated operation of the microgrid MG, the server 100 repeatedly executes the power regulation based on the processing in S12.

[0090] In the event of an anomaly (e.g., a power outage) in the power system PG (as described in S11), the second switching unit 114 initiates processing in S13 to switch from interlocked operation to independent operation. In S13, the second switching unit 114 determines the master and slave units from the DER group 500. Hereinafter, using... Figure 4 and Figure 5 This illustrates an example of host selection during independent handover. In the following description, during the processing timing of S13, Figure 4 Each DER shown is in a state where it can respond to adjustment commands from server 100.

[0091] Figure 4 This is a diagram showing the first example of the configuration of the DER around the receiving substation 501 (linkage point). Figure 4 The power regulation resources shown (hereinafter referred to as "R") are included in DER group 500. R21, R22, R23, and R24 are respectively connected to BEV or FCEV. Figure 1 The EVSE20 shown is connected to form a structure. R21, R22, R23, and R24 respectively contain... Figure 1The diagram shows FCEV12B, BEV11A, FCEV12A, and BEV11B. R61 and R62 are respectively equivalent to... Figure 1 The ESS60 shown. R71 and R72 are respectively equivalent to Figure 1 The FCS70 shown.

[0092] Reference Figure 4 The distances between the linkage points of each DER (distances from the receiving substation 501) are in the order of the shortest distances: R21, R22, R71, R61, R62, R23, R72, R24.

[0093] Figure 5 It means targeting Figure 4 The diagram shows the priority order of host selection when each DER is switched independently. Figure 5 R21~R24, R61, R62, R71 and R72 in Figure 4 Same. Figure 5 In this context, "distance" refers to the distance between the linkage points, and "output" refers to the maximum output power. Figure 5 In the diagram, A through H are ordered as A, B, C, D, E, F, G, H, in the order of height / largest / longest.

[0094] Reference Figure 5 , Figure 4 The capacities (kWh) of the DERs shown are in descending order as R62(A), R71(B), R61(C), R72(D), R21 / R22 / R23(E), and R24(F).

[0095] Reference Figure 4 and Figure 5 as well as Figure 3 Second switching unit 114 ( Figure 2 In S13, R62 with the largest capacity is selected as the host. The second switching unit 114 can refer to the storage device 120 ( Figure 2 The second switching unit 114 obtains the capacity of each DER by analyzing the resource information within the DER. Furthermore, the second switching unit 114 will treat R21-R24, R61, R71, and R72, which were not selected as masters in S13, as slaves. Additionally, the second switching unit 114 can be further equipped with... Figure 4 The DER, not shown, is a slave device.

[0096] Refer again Figure 1 and Figure 2 as well as Figure 3Following the processing in S13, the second switching unit 114 switches the microgrid MG from linked operation to independent operation in S14. More specifically, the second switching unit 114 disconnects the microgrid MG by receiving a circuit breaker from the transformer equipment 501. Thus, the microgrid MG is separated from the power system PG. Furthermore, the second switching unit 114 switches the power control mode of the microgrid MG from current control synchronized with the power system PG to master-slave control. When processing in S14 is executed, Figure 3 The series of processes shown has concluded; the following instructions will now begin. Figure 6 The processing is shown.

[0097] Figure 6 This is a flowchart illustrating the power regulation and control performed by server 100 during the independent operation of the microgrid MG. (Refer to...) Figure 1 and Figure 2 as well as Figure 6 In S21, the first switching unit 112 determines whether the abnormal power system PG (external power grid) has been restored. If the power system PG has not been restored (S21 is not), the first switching unit 112 proceeds to S23 in order to continue operating independently.

[0098] In S23, the second operating unit 113 performs operations based on... Figure 3 The master and slave units are controlled in S13. The second operation unit 113 controls the master and slave units by sending adjustment commands to the master and slave units respectively to stabilize the power of the microgrid MG. The master unit operates, for example, for CVCF control. Each slave unit operates for current control according to the frequency and voltage determined by the master unit. In the independent operation of the microgrid MG, the server 100 repeatedly performs power regulation based on the processing in S23. In addition, the second operation unit 113 can also change at least one of the master and slave units as needed. Furthermore, the second operation unit 113 can also increase or decrease the number of slave units as needed.

[0099] If the power system PG is restored (as in S21), the first switching unit 112 determines in S22 whether the regulation force of the microgrid MG is sufficient. For example, if the regulation force DER used to maintain the power quality of the microgrid MG above a specified level is ensured, it is determined to be yes in S22. On the other hand, if the regulation force DER is not ensured, it is determined to be no in S22. If the determination is yes in S22, the first switching unit 112 proceeds to S23 to continue independent operation. If the determination is no in S22, the first switching unit 112 proceeds to S24 to switch from independent operation to interlocked operation.

[0100] In this way, the first switching unit 112 determines the timing for switching the microgrid MG from independent operation to interlocking operation based on the regulating power of the microgrid MG during independent operation. The first switching unit 112 determines whether it is possible to continue independent operation based on the regulating power of the microgrid MG, and continues independent operation if it is possible to continue independent operation. In this way, the number of interlocking switches can be reduced.

[0101] In S24, the process described below Figure 7 is executed. Figure 7 is a flowchart showing the process of interlocking switching executed by the server 100. Refer to Figure 1 and Figure 2 and Figure 7 , in S31, the first switching unit 112 determines the master and slave units from the DER group 500. Hereinafter, the first example of master selection during interlocking switching will be described using Figure 4 and Figure 8 . In the following description, at the processing timing of S31, Figure 4 each of the DERs shown becomes in a state capable of responding to a synchronization command from the server 100.

[0102] Figure 8 is a diagram showing the priority order in master selection during interlocking switching for Figure 4 each of the DERs shown. Figure 8 R21 to R24, R61, R62, R71, and R72 in Figure 4 are the same as Figure 8 A to H in Figure 5 are the same as

[0103] Refer to Figure 4 , Figure 7 and Figure 8 . When a DER (a DER capable of responding to a synchronization command) shown in Figure 4 is a master candidate, the first switching unit 112 ( Figure 2 ) in Figure 7 S31 removes DERs with a communication speed lower than the first threshold and DERs with a maximum output power (kW) lower than the second threshold from the master candidates (that is, R21 to R24, R61, R62, R71, and R72). In the present embodiment, the first threshold is a speed higher than C and lower than B. Therefore, R21 with a communication speed of C is removed from the master candidates. In addition, the second threshold is greater than C and less than B. Therefore, R24 with a maximum output power of C is removed from the master candidates. The first switching unit 112 can obtain the communication speed and the maximum output power of each DER by referring to the resource information in the storage device 120 ( Figure 2 ).

[0104] Next, the first switching unit 112 ( Figure 2 The first switching unit 112 selects the R22 closest to the receiving substation 501 (linkage point) from the remaining host candidates (i.e., R22, R23, R61, R62, R71, and R72) as the host. The first switching unit 112 can select the host based on the storage device 120 (…). Figure 2 The system obtains the resource information within each DER (e.g., the latitude and longitude of each DER) and the distance between the linkage points of each DER. The shorter the linkage point distance, the higher the priority of the host selection.

[0105] Next, use Figure 9 and Figure 10 This describes the second example of the host selected during the linkage switch. In the following description, in... Figure 7 The processing timing of S31, Figure 9 Each DER shown is in a state where it can respond to synchronization commands from server 100.

[0106] Figure 9 This is a diagram showing the second example of the configuration of the DER around the receiving substation 501 (interlocking point). Figure 9 Examples other than those where R22 and R23 were not formed are similar to Figure 4 The examples are the same.

[0107] Figure 10 It means targeting Figure 9 The diagram shows the priority order of each DER in host selection during linkage switching. Figure 10 In the diagram, A through F are ordered as A, B, C, D, E, F, based on their height / largest / longest dimensions.

[0108] Reference Figure 7 , Figure 9 and Figure 10 ,exist Figure 9 When the DER (a DER capable of responding to synchronization commands) shown is a host candidate, in Figure 7 In step S31, firstly, R21, whose communication speed is lower than a first threshold, and R24, whose maximum output power (kW) is lower than a second threshold, are removed from the host candidates (i.e., R21, R24, R61, R62, R71, and R72). Then, R71, which is closest to the receiving substation 501 (connection point), is selected as the host from the remaining host candidates (i.e., R61, R62, R71, and R72).

[0109] Refer again Figure 1 and Figure 2 and Figure 7In step S31, the first switching unit 112 selects a master from among the multiple DERs existing around the linkage point as described above. Furthermore, in step S31, the first switching unit 112 designates master candidates that were not selected as masters (i.e., DERs with a priority order of second or lower) as slaves. Further, the first switching unit 112 may also add DERs other than master candidates as slaves.

[0110] In S32, the first switching unit 112 acquires the voltage waveform of the power system PG, and in S33, it acquires the amplitude and phase of the voltage waveform. In S34, the first switching unit 112 performs master-slave control based on the master and slave devices determined in S31. The first switching unit 112 controls the master and slave devices in a manner that synchronizes the power of the microgrid MG with the power of the power system PG by sending synchronization commands to the master and slave devices respectively. The master device operates, for example, for CVCF control. Each slave device operates for current control according to the frequency and voltage determined by the master device.

[0111] In S35, the first switching unit 112 determines whether the phase difference between the power of the power system PG and the power of the microgrid MG is below a predetermined allowable value Th11. Furthermore, in S36, the first switching unit 112 determines whether the amplitude difference (voltage difference) between the power of the power system PG and the power of the microgrid MG is below a predetermined allowable value Th12. During the period when either S35 or S36 is incorrect (the difference exceeds the allowable value), S32 to S36 are repeated to perform master-slave control (S34) in a manner that reduces the phase difference and amplitude difference. Then, when both S35 and S36 are correct, the process proceeds to S37. A correct result in both S35 and S36 signifies that synchronization based on master-slave control has been completed.

[0112] In S37, the first switching unit 112 switches the microgrid MG from independent operation to interlocked operation. More specifically, the first switching unit 112 connects the microgrid MG in parallel with the power system PG by activating the circuit breaker (interlocked circuit breaker) of the receiving transformer 501. Furthermore, the first switching unit 112 switches the power control mode of the microgrid MG from master-slave control to current control synchronized with the power system PG. When the processing in S37 is executed, the process returns... Figure 6 The process (S24), Figure 6 The series of processes shown is now complete. Then, as the microgrid MG begins to operate in tandem, the aforementioned process begins... Figure 3 The processing.

[0113] As described above, the power management method of this embodiment is a method of managing the power of the microgrid MG using multiple DERs that can be electrically connected to the microgrid MG, including... Figure 7The steps S31, S34, and S37 are shown. In S31, when switching the microgrid MG from independent operation to coordinated operation with the power system PG, the server 100 determines the master and slave from multiple DERs that can be electrically connected to the microgrid MG. In S31, the DER closest to the linkage point (the connection point between the microgrid MG and the power system PG) is preferentially selected as the master. In S34, the server 100 implements master-slave control based on the master and slave to synchronize the power of the microgrid MG with the power of the power system PG. After implementing synchronization based on master-slave control, the server 100 connects the microgrid MG and the power system PG in parallel in S37.

[0114] According to the above method, when the microgrid MG switches from independent operation to linked operation, the instability of the power supply of the microgrid MG is suppressed.

[0115] In the above embodiments, Figure 3 S13 and Figure 7 In S31, the host is selected from multiple DERs existing around the linkage point. However, in Figure 3 In S13, a DER located far from the linkage point can also be selected as the master unit. For example, in the case of a large-capacity DER located far from the linkage point, Figure 3 In the S13, this high-capacity DER can also be selected as the host.

[0116] exist Figure 3 S13 and Figure 7 In S31, at least one of the following can also select multiple hosts. Multiple hosts can, for example, be selected based on... Figure 5 or Figure 8 The priority order shown is selected in descending order. Furthermore, in master-slave control, multiple master units can collaboratively determine the frequency and voltage of the microgrid MG.

[0117] exist Figure 6 S23 and Figure 7 In at least one of S34, the type of DER used for master-slave control can be appropriately changed. Server 100 may also use at least one of EVSE, ESS, and FCS installed in residential 30 for master-slave control. Furthermore, server 100 may also use at least one of EVSE, ESS, and FCS installed in factory 50 for master-slave control.

[0118] In the above embodiment, the geographical distance from the linkage point to the power regulation resource is used as the linkage point distance. However, it is not limited to this; the length of the power line (transmission line and distribution line) from the linkage point to the power regulation resource can also be used as the linkage point distance. Furthermore, in the above embodiment, a rule-based procedure is used. However, the first switching unit 112 can also comprehensively evaluate the linkage point distance, communication performance, and output performance of each DER included in the DER group 500 based on a relational expression obtained through statistical learning using big data, and preferentially select the DER with the best evaluation result as the host. Alternatively, a learned model obtained through machine learning using AI (artificial intelligence) can be used instead of the relational expression.

[0119] In the above embodiments, server 100 remotely operates electric vehicles (BEVs and FCEVs) via wireless communication, thereby enabling the electric vehicles to function as DERs. However, the invention is not limited to this; the electric vehicles included in the DER group 500 may not include communication devices for wireless communication with server 100. Server 100 may also remotely operate electric vehicles via wired communication through EVSE 20, thereby enabling the electric vehicles to function as DERs. Generally, wired communication is faster than wireless communication. For example, Figure 4 The BEV11A, 11B and FCEV12A, 12B shown each communicate with the server 100 via EVSE20, thereby... Figure 4 The communication speed of each of R21 to R24 shown can also be "A".

[0120] Figure 11 It means Figure 8 The diagram shows a variation of the priority order in host selection during linkage switching. Figure 11 R21~R24, R61, R62, R71 and R72 in the context of Figure 4 same. Figure 11 In principle, A to H are related to Figure 8 Same. However, in this variation, the communication speed of each of R21 to R24 is A. (Refer to...) Figure 11 In this modified example, during the selection of the host during linkage switching, R24, whose maximum output power is C, is removed from the host candidates. Then, among the remaining host candidates (i.e., R21 to R23, R61, R62, R71 and R72), R21, which is closest to the receiving substation 501 (connection point), is selected as the host.

[0121] exist Figure 6In the illustrated process, even if the power system PG recovers, it continues to operate independently until the regulation capacity of the microgrid MG becomes insufficient. However, this is not the only possibility; a coordinated switchover can also be performed immediately after the power system PG recovers. Furthermore, since an anomaly may occur again immediately after the power system PG recovers, it can also continue to operate independently until the power system PG stabilizes.

[0122] Figure 12 It means Figure 6 A diagram showing a variation of the processing. Figure 12 The process shown replaces S22 ( Figure 6 In addition to adopting S22A, it is compatible with... Figure 6 The processing shown is the same. S22A will be explained below.

[0123] Reference Figure 1 and Figure 2 as well as Figure 12 When the power system PG (external power grid) is restored (yes in S21), the first switching unit 112 determines in S22A whether a predetermined time has elapsed since the restoration. If the predetermined time has not elapsed since the restoration (no in S22A), the first switching unit 112 proceeds to S23 to continue independent operation. If the predetermined time has elapsed since the restoration (yes in S22A), the first switching unit 112 proceeds to S24 to switch from independent operation to interlocked operation.

[0124] As in the aforementioned variation, server 100 can continue to operate independently until a predetermined time has elapsed since the power system PG was restored. Furthermore, server 100 can also perform a coordinated switchover after the predetermined time has elapsed since the power system PG was restored.

[0125] exist Figure 7 If the host identified in S31 is an electric vehicle (e.g., BEV or FCEV), the first switching unit 112 can also reduce the DR of the microgrid MG before implementing master-slave control for synchronization. Reduced DR is a DR (demand response) requesting a reduction in user demand. Figure 13 It means Figure 7 A diagram illustrating a modified example of the processing. In this modified example, in... Figure 7 Add between S31 and S32 of the process shown Figure 13 S41 to S43 are shown. S41 to S43 will be explained below.

[0126] Reference Figure 1 and Figure 2 as well as Figure 13After processing in S31, the first switching unit 112 determines in S41 whether the host determined in S31 is an electric vehicle. If the host is not an electric vehicle (not determined in S41), processing proceeds to S32 (see reference). Figure 7 In the case where the host is an electric vehicle (yes in S41), in S42, the first switching unit 112 performs a reduction DR on the microgrid MG. The first switching unit 112 requests a reduction in the demand of the microgrid MG from users (demanders) of one or more DERs included in the DER group 500 by reducing the DR. The amount by which the demand of the microgrid MG is reduced by reducing the DR can also be determined based on the host's capacity (kWh). The reduction DR signal requesting a reduction in the demand of the microgrid MG can also be sent from the server 100 to the EMS managing the DER, or to the user terminal of the DER (e.g., portable terminal 10). In S43, the first switching unit 112 determines whether the reduction in the demand of the microgrid MG based on the reduction DR has been completed. When the reduction DR implemented in S42 is completed (yes in S43), the process proceeds to S32 (see reference). Figure 7 ).

[0127] In the above variation, when the host is an electric vehicle, the first switching unit 112 requests a reduction in the demand of the microgrid MG from users in one or more DERs included in the DER group 500 before implementing master-slave control for synchronization. By reducing the demand of the microgrid MG before implementing master-slave control-based synchronization, the reduction in synchronization accuracy due to insufficient host capacity is suppressed.

[0128] Server 100 can also collaborate with other servers to control DER group 500. It is also possible to group the DERs contained in DER group 500 and set up a server for each group (e.g., a server managing the DERs within the group). For example, a server could be set up for each EMS to control the EMS. Server 100 can then control DER group 500 through the servers in each group.

[0129] The structure of the electric vehicle used as a power regulation resource is not limited to the structure shown in the above embodiments. For example, a plug-in hybrid electric vehicle (PHEV) may also be used as a power regulation resource. The electric vehicle may also be configured to be capable of contactless charging. The electric vehicle is not limited to a passenger car, but may also be a bus or a truck. The electric vehicle may be configured to be capable of autonomous driving or may have flight capabilities. DER Group 500 may also include electric vehicles capable of unmanned operation (e.g., automated guided vehicles (AGVs) or agricultural machinery).

[0130] Power regulation resources are not limited to Figure 1The DER shown. For example, an induction motor with a flywheel can also be used as a power regulation resource.

[0131] While embodiments of the invention have been described, they should be considered illustrative and not restrictive in all respects. The scope of the invention is defined by the claims, which include all modifications equivalent to the spirit and scope of the claims.

Claims

1. A server that implements power management for a primary power grid. The first power grid is configured to be able to connect in parallel and disconnect from the second power grid. The server has: The resource management department manages multiple power regulation resources that can be electrically connected to the first power grid; The first switching unit, when switching the first power grid from independent operation to coordinated operation with the second power grid, determines the master and slave units from the plurality of power regulation resources. After implementing master-slave control based on the master and slave units in a manner that synchronizes the power of the first power grid with the power of the second power grid, it connects the first power grid and the second power grid in parallel. The first switching unit is configured to preferentially select, from the plurality of power regulation resources, the power regulation resource with power output capability that is closest to the connection point between the first power grid and the second power grid as the main unit. The multiple power regulation resources include electric vehicles. The first switching unit is configured to, when the host is the electric vehicle, request a reduction in demand from the user of one or more of the power regulation resources included in the plurality of power regulation resources before implementing the master-slave control. The server also has a second switching unit, which determines the master and slave units from the plurality of power regulation resources when switching the first power grid from interlocked operation to independent operation. The second switching unit is configured to preferentially select the power regulation resource with the largest capacity and power output capability among the plurality of power regulation resources as the host.

2. The server according to claim 1, wherein, The first switching unit is configured to select the host based on the communication performance and output performance of the power regulation resource.

3. The server according to claim 2, wherein, The first switching unit is configured to remove power regulation resources with communication speeds below a first threshold and power regulation resources with maximum output power below a second threshold from the power regulation resources capable of responding to synchronization commands, and select the remaining power regulation resources that are closest to the connection point as the host.

4. The server according to claim 1, wherein, The plurality of power regulation resources also include stationary energy storage devices.

5. The server according to claim 1, wherein, The electric vehicle in question is a fuel cell vehicle.

6. The server according to any one of claims 1 to 5, wherein, The first switching unit is configured to determine the timing for switching the first power grid from independent operation to interlocked operation based on the regulating capacity of the first power grid when it is operating independently.

7. The server according to any one of claims 1 to 5, wherein, The first power grid is a microgrid. The second power grid is a commercial power system provided by power companies. Each of the multiple power regulation resources has a power conversion circuit. In the master-slave control, the master unit, which is electrically connected to the first power grid, implements voltage control through the power conversion circuit, and the slave unit, which is also electrically connected to the first power grid, implements current control through the power conversion circuit.

8. A power management method, which implements power management of a first power grid capable of being connected in parallel with and disconnected from a second power grid, comprising: When switching the first power grid from independent operation to linkage operation with the second power grid, the step of determining the master and slave units from multiple power regulation resources that can be electrically connected to the first power grid is as follows: The master-slave control steps based on the master and slave devices are implemented in a manner that synchronizes the power of the first power grid with the power of the second power grid. After implementing synchronization based on the master-slave control, the step of connecting the first power grid and the second power grid in parallel is as follows: In determining the master and slave units during the linkage switching, the master unit is preferentially selected from among the multiple power regulation resources that is closest to the connection point between the first power grid and the second power grid and has power output capability. The multiple power regulation resources include electric vehicles. In the case where the host is the electric vehicle, prior to implementing the master-slave control step, a request is made to the user of one or more of the power regulation resources included in the plurality of power regulation resources to reduce the demand of the first power grid. The power management method further includes: when switching the first power grid from linked operation to independent operation, determining the master and slave from the plurality of power regulation resources, wherein the power regulation resource with the largest capacity and power output capability among the plurality of power regulation resources is preferentially selected as the master.

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