Network system and method for controlling the network system

Abstract

A network system 1 includes a wireless base station for relaying communication performed by a wireless terminal, a plurality of distributed antennas which are connected to the wireless base station and each of which forms a cell enabling communication with the wireless terminal, a plurality of direct current grids which are arranged in a predetermined form in a communication area formed by the plurality of cells, and which exchange electric power with a plurality of electric power devices connected to the direct current grids themselves, electric power gates which are provided between the direct current grids that are adjacent to one another, and which perform interchange of electric power between the direct current grids, and a control device which controls the electric power gates on the basis of information acquired from the electric power devices via the distributed antennas, wherein the electric power devices connected to the direct current grids communicate with the control device via the distributed antennas that form the communication area including the direct current grids.

Description

[Technical Field]

[0001] The present invention relates to a network system and a method for controlling a network system. [Background technology]

[0002] Smart cities and compact cities, which realize Society 5.0 by highly integrating the cyberspace and physical space of CPS (Cyber ​​Physical System), are expected to realize the efficiency and sophistication of urban and regional functions and services, as well as to achieve both the resolution of social issues such as decarbonization and economic development through changes in industrial structure brought about by digital transformation.

[0003] With the rise in investments that take into account the three elements of environment, society, and governance (ESG investments) and the adoption of the 2030 Agenda for Sustainable Development (Sustainable Development Goals (SDGs)) at the United Nations Summit in September 2015, the number of members of RE100 (Renewable Energy 100%), which is open to companies that have declared that they will operate their businesses using only renewable energy, is also increasing.

[0004] The global smart city market is estimated to reach a cumulative scale of 3,100 trillion yen over the 20 years from 2010 to 2030, with the core energy-related market expected to reach approximately 720 trillion yen for smart grids, approximately 310 trillion yen for next-generation automobiles such as electric vehicles, and approximately 380 trillion yen for renewable energy.As a result, many countries and regions are promoting smart city plans, and some of these plans are already underway.

[0005] Patent Document 1 proposes a system in which distributed power sources including solar power generation, wind power generation, storage batteries, and power storage systems, social infrastructure including EVs and charging stations, a Home Energy Management System (HEMS), a Building Energy Management System (BEMS), and a power plant are interconnected by a communication grid and a power grid.

[0006] Furthermore, as an invention for exchanging power between multiple power cells to make up for power shortages in the power grid, for example, there is a power network system disclosed in Patent Document 1. The power cell disclosed in Patent Document 1 includes loads such as homes and buildings, power generation equipment such as solar panels and wind turbines, power storage equipment such as batteries, and a power router. This power router is connected to the power routers of other power cells and to a main grid that transmits power from power plants. The power router of each cell is connected to a management server via a communication network and controlled by the management server to exchange power between the power cells. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2013 / 172088 [Patent Document 2] International Publication No. 2014 / 061259 Summary of the Invention [Problem to be solved by the invention]

[0008] In the power network system disclosed in Patent Document 1, because the power routers are centrally controlled, if a failure occurs between the power routers and the management server device due to a disaster or other reason, power interchange between the power cells becomes impossible. Although it is possible to respond to the failure by applying autonomous distributed control, it is difficult to optimize the entire system and interchange power using autonomous distributed control alone, so technology to enhance resilience is required.

[0009] The present invention has been made in view of the above, and aims to provide a technology for enhancing resilience in a network in which a power network and a communication network are integrated. [Means for solving the problem]

[0010] A network system according to one embodiment of the present invention comprises a wireless base station that relays communications between wireless terminals, a plurality of distributed antennas connected to the wireless base station and each forming a cell that enables communication with the wireless terminal, a plurality of DC grids that are arranged in a predetermined form within a communication area formed by the plurality of cells and that exchange power with a plurality of power devices connected to the grid, power gates that are provided between adjacent DC grids and that exchange power between the DC grids, and a control device that controls the power gates based on information obtained from the power devices via the distributed antennas, and the power devices connected to the DC grids communicate with the control device via the distributed antennas that form the communication area that includes the DC grids.

[0011] The DC grid may be in the form of a bus.

[0012] The DC grid may have a star configuration.

[0013] The DC grid may be in the form of a ring.

[0014] The DC grid may be in the form of a mesh.

[0015] A network system according to one embodiment of the present invention may include a plurality of the wireless base stations, a control device provided for each of the wireless base stations, and a centralized control device that controls the plurality of control devices based on information acquired from the power equipment, and the control device may control the power gates under control from the centralized control device to control power interchange between DC grids.

[0016] The power gate may be configured to, when interchange of power is performed, make the voltage of the DC grid on the power supply side higher than the voltage of the DC grid on the power supply side.

[0017] One aspect of the present invention is a control method for a network system having a wireless base station that relays communications between wireless terminals, a plurality of distributed antennas connected to the wireless base station and each forming a cell that enables communication with the wireless terminal, a plurality of DC grids that are arranged in a predetermined form within a communication area formed by the plurality of cells and that exchange power with a plurality of power devices connected to the grid, power gates that are provided between adjacent DC grids and that exchange power between the DC grids, and a control device that controls the power gates based on information acquired from the power devices via the distributed antennas, the method comprising the steps of: the control device acquiring information transmitted from the power devices via the distributed antennas; and the control device controlling the power gates so that power is exchanged between the DC grids based on the acquired information. [Effects of the Invention]

[0018] The network system of the present invention includes a wireless base station that relays communications between wireless terminals, a plurality of distributed antennas connected to the wireless base station and each forming a cell that enables communication with the wireless terminal, a plurality of DC grids arranged in a predetermined pattern within a communication area formed by the plurality of cells and exchanging power with a plurality of connected power devices, a power gate provided between adjacent DC grids and exchanging power between the DC grids, and a control device that controls the power gate based on information acquired from the power devices via the distributed antennas, and the power devices connected to the DC grids communicate via the distributed antennas that form the communication area including the DC grid. Even if a distributed antenna is damaged due to a disaster, other distributed antennas that are not damaged are still operating, so the power devices connected to the DC grid can be reconnected to the other distributed antennas that are not damaged and can be restored, thereby enhancing resilience.

[0019] A control method for a network system of the present invention includes a wireless base station that relays communications between wireless terminals, a plurality of distributed antennas connected to the wireless base station and each forming a cell that enables communication with the wireless terminal, a plurality of DC grids that are arranged in a predetermined pattern within a communication area formed by the plurality of cells and that exchange power with a plurality of connected power devices, power gates that are provided between adjacent DC grids and that exchange power between the DC grids, and a control device that controls the power gates based on information acquired from the power devices via the distributed antennas, the control device comprising the steps of: acquiring information transmitted from the power devices via the distributed antennas; and controlling the power gates based on the acquired information so that power is exchanged between the DC grids. Even if a distributed antenna fails due to a disaster, other distributed antennas that are not failed are still operating, so that the power devices connected to the DC grid can be returned to the other distributed antennas that are not failed, thereby enhancing resilience. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a diagram showing the configuration of a network system according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram of a small cell formed by an antenna. [Figure 3] FIG. 3 is a diagram schematically showing a bus-shaped DC grid and small cells arranged in a communication area. [Figure 4] FIG. 4 is a schematic diagram showing the configuration of a power gate. [Figure 5] FIG. 5 is a diagram showing the configuration of a base station and a DC grid. [Figure 6] FIG. 6 is a diagram for explaining a method of power interchange. [Figure 7] FIG. 7 shows a star-shaped DC grid arrangement. [Figure 8] FIG. 8 shows a star-shaped DC grid arrangement. [Figure 9] FIG. 9 is a diagram showing the arrangement of a ring-shaped DC grid. [Figure 10] FIG. 10 is a diagram showing the layout of a mesh-like DC grid. [Figure 11] FIG. 11 is a diagram showing the layout of a mesh-like DC grid. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments described below. In addition, in the description of the drawings, the same or corresponding elements are appropriately designated by the same reference numerals.

[0022] [Embodiment] 1 is a diagram showing the configuration of a network system according to one embodiment of the present invention. Network system 1 is a power and communication integrated network that combines a wireless communication network conforming to the 5G (fifth generation mobile communication system) standard, including base stations 10A, 10B, and multiple antennas ANT, with a power network formed of multiple DC grids GR11 to GRmn, which are power transmission networks.

[0023] Base station 10A and base station 10B are wireless base stations forming a 5G wireless communication network. 5G is characterized by "ultra-high speed," "ultra-low latency," and "multiple simultaneous connections." "Ultra-low latency" guarantees a communication delay time of, for example, approximately 1 millisecond or less. The wireless communication standard is not limited to 5G, but may be a communication standard for a post-5G generation mobile communication system called B (Beyond) 5G. A communication standard with guaranteed communication delay time is preferable. Base station 10A forms a communication area CELL1 using multiple antennas ANT, enabling communication with wireless terminals performing 5G wireless communication. Base station 10B forms a communication area CELL2 using multiple antennas ANT, enabling communication with wireless terminals performing 5G wireless communication. While FIG. 1 illustrates two base stations 10A and 10B, the number of base stations included in network system 1 is not limited to two and may be three or more.

[0024] A plurality of antennas ANT are arranged within the communication area CELL1 and the communication area CELL2. The antennas ANT are distributed antennas that form a 5G wireless communication network. The antennas ANT have the function of an RU (Radio Unit) in 5G wireless communication. Each of the plurality of antennas ANT connected to base station 10A by an optical fiber cable forms a small cell that enables communication with wireless terminals, and these plurality of small cells form the communication area CELL1. Each of the plurality of antennas ANT connected to base station 10B by an optical fiber cable forms a small cell that enables communication with wireless terminals, and these plurality of small cells form the communication area CELL2.

[0025] Fig. 2 is a schematic diagram of a communication area CELL1 corresponding to the base station 10A and small cells SCEL11 to SCEL88 formed by antennas ANT connected to the base station 10A. To avoid the drawing becoming too complicated, Fig. 2 omits the illustration of optical fiber cables connecting each of the multiple antennas ANT to the base station 10A.

[0026] For example, communication area CELL1 is within a range with a radius of 1 km centered on base station 10A, and each of small cells SCEL11 to SCEL88 formed by antenna ANT is within a range with a radius of 125 m centered on antenna ANT, but in Fig. 2, for simplicity, communication area CELL1 is shown by a solid square line, and each of small cells SCEL11 to SCEL88 is shown by a dashed square line. In this embodiment, it is assumed that radio waves exchanged between antenna ANT and wireless terminals are in the millimeter wave band, and 64 antennas ANT are arranged in consideration of radio wave propagation, and 64 small cells SCEL11 to SCEL88 are formed. Note that 64 antennas ANT are also arranged for base station 10B, and 64 small cells SCEL11 to SCEL88 are formed.

[0027] The last two digits of the codes of small cells SCEL11 to SCEL88 correspond to the position of each of the small cells SCEL11 to SCEL88 modeled as a matrix, with the last digit of the code corresponding to the column position of the small cells SCEL11 to SCEL88 and the second last digit of the code corresponding to the row position of the small cells SCEL11 to SCEL88. For example, in Figure 2, the cell in the second row and second column is called small cell SCEL22.

[0028] Returning to FIG. 1, in the communication area CELL1 and the communication area CELL2, a bus BUS is installed in a communication area formed by a predetermined number of antennas ANT. The bus BUS forming a DC grid is a DC power line to which a plurality of power devices including power generation devices and power storage devices are connected. In this embodiment, one bus BUS is installed in each of the communication areas formed by four adjacent antennas ANT. In the communication area CELL1 and the communication area CELL2, a DC grid GR11 to GRmn, which is a DC power transmission network, is formed by the plurality of buses BUS.

[0029] FIG. 3 is a diagram schematically illustrating 16 buses BUS arranged in a communication area CELL1, DC grids GR11 to GR44 formed by the 16 buses BUS, and small cells covering each of the DC grids GR11 to GR44. In FIG. 3, the DC grids GR11 to GR44 are modeled as m rows and n columns, and the base station 10A is not shown to avoid cluttering the drawing. The last two digits of the reference numerals of the DC grids GR11 to GR44 correspond to the positions of the DC grids GR11 to GR44, which are modeled as 4 rows and 4 columns. The last digit of the reference numeral corresponds to the column position of the DC grids GR11 to GR44, and the penultimate digit of the reference numeral corresponds to the row position of the DC grids GR11 to GR44. For example, in FIG. 3, the DC grid in the second row and second column is called DC grid GR22. Each of the DC grids GR11 to GR44 shown in FIG. 3 is an example of a bus-shaped DC grid.

[0030] The bus BUS has a baseline length of, for example, 1 km, and is bent and arranged in four rows and four columns to form DC grids GR11 to GR44. The bus BUS supplies power at a voltage of, for example, 400 V. Note that, to areas of small cells where the bus BUS is not located in FIG. 3, power is supplied, for example, by branch lines (not shown) extending from the bus BUS. Each of the DC grids GR11 to GR44 is covered for wireless communication in a communication area formed by small cells arranged in two rows and two columns, and the bus BUS supplies power to the antenna ANT. For example, the DC grid GR11 is covered for wireless communication by small cells SCEL11, SCEL12, SCEL21, and SCEL22, and the bus BUS forming the DC grid GR11 supplies power to the antenna ANT forming small cell SCEL11, the antenna ANT forming small cell SCEL12, the antenna ANT forming small cell SCEL21, and the antenna ANT forming small cell SCEL22.

[0031] Between the DC grids, power gates GA are provided to exchange power between the DC grids. FIG. 4 is a schematic diagram showing the configuration of the power gate GA. The power gate GA has four DC / DC converters GCON1 to GCON4. One end of each of the DC / DC converters GCON1 to GCON4 is connected to one bus BUS, and the other ends are connected to each other. Note that in the power gate GA, there may be DC / DC converters to which no bus BUS is connected depending on the positional relationship with the DC grids GR11 to GR44. Furthermore, at least one of the power gate GAs arranged in one communication area CELL1 is connected to a power gate GA arranged in another communication area CELL2, thereby exchanging power across the communication areas. Note that the number of DC / DC converters included in the power gate GA may correspond to the number of buses BUS to which it is connected. The power gate GA has 5G wireless communication capabilities and also functions as a wireless terminal, communicating information with an MEC server 101 (described later) via an antenna ANT.

[0032] Returning to FIG. 1, the cloud system 2 is a system that provides various services via a network such as the Internet, and includes a centralized control device 1000. The centralized control device 1000 is connected to the base station 10A and the base station 10B. The centralized control device 1000 is a server device that has the function of controlling power interchange between the DC grids GR11 to GR44 included in the communication area CELL1 and the DC grids GR11 to GR44 included in the communication area CELL2.

[0033] Fig. 5 is a diagram showing an example of the configuration of the base station 10A and DC grids GR11 and GR12. Note that, because the configuration of the base station 10B is the same as that of the base station 10A, Fig. 5 shows the configuration of the base station 10A as a representative, and does not show the configuration of the base station 10B. Also, to prevent the drawing from becoming too complicated, Fig. 5 shows the configurations of the DC grids GR11 and GR12 as representatives of the DC grids GR11 to GR44 included in the communication area CELL1 corresponding to the base station 10A.

[0034] The base station 10A has an MEC server 101, an AC / DC converter 102, a power storage device 103, and a CU / DU 104. The DC grids GR11 and GR12 have a bus BUS, converters CON1 to CON4, and power elements EL1 to EL4, and each of the DC grids GR11 and GR12 is covered for wireless communication by a communication area formed by four antennas ANT.

[0035] First, the configuration of the base station 10A will be described. The AC / DC converter 102 is connected to a commercial power system 3. The AC / DC converter 102 converts AC power supplied from the power system 3 into DC power and supplies it to the MEC server 101 and the power storage device 103.

[0036] The power storage device 103 is composed of one or more storage batteries. A power generation device such as a renewable energy source may be connected to the power storage device 103. The power stored in the power storage device 103 is supplied to the MEC server 101 and the CU / DU 104 as driving power. The power storage device 103 may also supply power to the antenna ANT via a metal cable.

[0037] The CU / DU 104 has the functions of a CU (Central Unit) and a DU (Distributed Unit) in 5G communication. The CU / DU 104 is connected to a plurality of antennas ANT that form a communication area via optical fiber cables. The CU / DU 104 is also connected to the MEC server 101.

[0038] The MEC server 101, which is an example of a control device, is a MEC (Mobile Edge Computing) server device installed in a position close to a wireless terminal. The MEC server 101 includes a control unit 111, a storage unit 112, and a communication unit 113.

[0039] The control unit 111 performs various arithmetic processing to realize the functions of the MEC server 101, and is configured to include processors such as a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), a DSP (Digital Signal Processor), and a GPU (Graphics Processing Unit). The functions of the control unit 111 are realized by the control unit 111 reading and executing various programs from the storage unit 112. For example, the control unit 111 reads and executes various programs from the storage unit 112, thereby realizing functions such as a function of communicating information with the converters CON1 to CON4 and the power elements EL1 to EL4, a function of comprehensively managing the states of the DC grids GR11 to GR44 installed in the communication area CELL1, a function of centrally controlling the converters CON1 to CON4, a function of controlling power interchange between the DC grids GR11 to GR44, and a function of controlling power interchange with DC grids installed in adjacent communication areas in response to instructions from the centralized control device 1000.

[0040] The storage unit 112 includes, for example, a ROM (Read Only Memory) that stores various programs and data used by the control unit 111 to perform arithmetic processing. The storage unit 112 also includes, for example, a RAM (Random Access Memory) that is used as a workspace when the control unit 111 performs arithmetic processing and for storing the results of the arithmetic processing of the control unit 111. The storage unit 112 may also include an auxiliary storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive).

[0041] The communication unit 113 includes a communication module that performs information communication via wire or wirelessly. The communication unit 113 is connected to the central control device 1000. The communication unit 113 performs information communication with the central control device 1000 via the Internet.

[0042] Next, the configuration of DC grids GR11 and GR12 will be described. As an example, power element EL1 is a stationary energy storage device that can supply, consume, and charge power, and is connected to converter CON1. ​​A stationary energy storage device is an example of a permanently installed in-facility energy storage device. Converter CON1 has the function of converting the voltage of DC power supplied by power element EL1 and outputting it to bus BUS, and also converting the voltage of DC power supplied from bus BUS and outputting it to power element EL1, thereby charging it.

[0043] The power element EL2 is, for example, a solar power generation device capable of generating and supplying power, and is connected to the converter CON2. A solar power generation device is an example of a power generation device that generates power using renewable energy. The converter CON2 has a function of converting the voltage of the DC power supplied by the power element EL2 and outputting the converted voltage to the bus BUS. Note that the power element EL2 is not limited to a solar power generation device, but may be a renewable energy source such as a wind power generation device or a geothermal power generation device. Note that if the power element EL2 is an element that does not control the amount of power generated from the viewpoint of efficiency, such as a solar power generation device, the converter CON2 may execute MPPT (Maximum Power Point Tracking) control, which operates when power corresponding to the amount of power generated by the power element EL2 is input, so that the output power to the bus BUS is maximized at that amount of power generated.

[0044] The power element EL3 is, for example, an on-board power storage device capable of supplying, consuming, and charging power, and is connected to the converter CON3. The on-board power storage device is mounted on an electric vehicle EV and is an example of a mobile, non-stationary power storage device. The converter CON3 has the function of converting the voltage of the DC power supplied by the power element EL3 and outputting it to the bus BUS, and also converting the voltage of the DC power supplied from the bus BUS and outputting it to the power element EL3 for charging. The converter CON3 is provided, for example, in a charging station or residential charging equipment, but may also be mounted on the electric vehicle EV.

[0045] As an example, power element EL4 is a ZEH (Net Zero Energy House) that can supply, consume, and charge power, and is connected to converter CON4. The ZEH has, for example, a solar power generation device, a storage battery, and electrical appliances such as an air conditioner and a refrigerator as power loads. Converter CON4 has the function of converting the voltage of the DC power supplied by power element EL4 and outputting it to bus BUS, and also converting the voltage of the DC power supplied from bus BUS and outputting it to power element EL4, thereby charging the storage battery.

[0046] Converters CON1 to CON4 have sensors that measure electrical characteristic values ​​of the power of the bus BUS, and measure electrical characteristic values ​​such as the current value, voltage value, and power value of the bus BUS. Converters CON1 to CON4 and power elements EL1 to EL4 are examples of power equipment. Each of converters CON1 to CON4 and power elements EL1 to EL4 also functions as a wireless terminal equipped with 5G wireless communication capabilities, and communicates information with the MEC server 101 via a single antenna ANT. For example, power elements EL1 to EL4 transmit information such as power generation capacity, power generation state, power storage capacity, power storage state, and power load to the MEC server 101, and converters CON1 to CON4 transmit the measured electrical characteristic values ​​to the MEC server 101. Also, for example, if power element EL1 is located in small cell SCEL11 and power element EL2 is located in small cell SCEL12, power element EL1 communicates via antenna ANT that forms small cell SCEL11, and power element EL2 communicates via antenna ANT that forms small cell SCEL12.

[0047] Furthermore, the converters CON1 to CON4 in the DC grids GR11 to GR44 are controlled by an energy management system (EMS). The hardware configuration of the EMS can be the same as that of the MEC server 101. The EMS is an example of a control device. For example, an EMS is provided corresponding to each of the DC grids GR11 to GR44. The EMS may be virtualized and provided in the MEC server 101. The EMS controls the converters CON1 to CON4 so that power is smoothed on the bus BUS according to the power supply state of the power elements EL1 to EL4. In the DC grids GR11 to GR44, the power generation capacity, power generation state, power storage capacity, power storage state, power load, and electrical characteristic values ​​of the bus BUS fluctuate from moment to moment, but by each EMS controlling each converter CON1 to CON4 in the DC grids GR11 to GR44, these fluctuations can be canceled out, power smoothing of the bus BUS is realized, and power supply and demand can be stabilized in each DC grid GR11 to GR44. Note that various control methods, such as feedback control, can also be applied to the control methods in the DC grids GR11 to GR44.

[0048] In this embodiment, when a DC grid installed within the communication area CELL1 experiences a power shortage, if a DC grid installed within the same communication area CELL1 has excess power, an EMS that receives information about a neighboring DC grid from the MEC server 101 controls a power gate GA, thereby allowing power to be diverted from that DC grid to the DC grid with the power shortage. Based on the information distributed from the MEC server 101, the EMS provided for each DC grid controls the power gate GA for the neighboring DC grid with the power shortage, thereby diverting power to the DC grid with the power shortage. In this embodiment, the MEC server 101 may, for example, identify the DC grid with the power shortage based on the electrical characteristic values ​​of the buses BUS of the acquired DC grids GR11 to GR44, and control the power gate GA to diverte power to the identified DC grid. Such control for diverting power between multiple nearby DC grids is an example of autonomous distributed cooperative control.

[0049] 6 is a diagram for explaining a method of power interchange via power gate GA. Buses BUS1 to BUS3 are DC power lines that make up the above-mentioned DC grid. Power gate GA1 is a power gate installed between bus BUS1 and bus BUS2, and power gate GA2 is a power gate installed between bus BUS2 and bus BUS3.

[0050] For example, when power is to be lent from bus BUS2 to bus BUS3, the EMS communicates with power gate GA1 and controls power gate GA1 so that DC / DC converter GCON1 and DC / DC converter GCON3 of power gate GA1 are open. The EMS also communicates with power gate GA2 and controls power gate GA2 so that the voltage on the DC / DC converter GCON3 side of DC / DC converter GCON1 of power gate GA2 is higher than the voltage on the DC / DC converter GCON1 side of DC / DC converter GCON3 of power gate GA2. By controlling power gate GA1 and power gate GA2 in this way, buses BUS1 and BUS2 are disconnected, and power is lent from bus BUS2 to bus BUS3.

[0051] Furthermore, for example, when power is to be lent from bus BUS1 to bus BUS3, the EMS controls power gate GA2 so that the voltage on the DC / DC converter GCON3 side of DC / DC converter GCON1 of power gate GA2 is higher than the voltage on the DC / DC converter GCON1 side of DC / DC converter GCON3 of power gate GA2. The EMS also controls power gate GA1 so that the voltage on the DC / DC converter GCON3 side of DC / DC converter GCON1 of power gate GA1 is higher than the voltage on the DC / DC converter GCON1 side of DC / DC converter GCON3 of power gate GA1. By controlling power gate GA1 and power gate GA2 in this manner, power is lent from bus BUS1 to bus BUS3 via bus BUS2, making it possible to lent power across DC grids and achieving smoothing of power supply and demand within the communication area under the jurisdiction of one MEC server 101.

[0052] For example, if a disaster causes a failure in the antenna ANT, it becomes impossible to obtain information from the power elements EL1-EL4 and the converters CON1-CON4 via the antenna ANT. In this case, for example, by dispatching a mobile base station in the form of a vehicle, the power elements EL1-EL4 and the converters CON1-CON4 can be quickly restored to the wireless communication network, and the EMS can obtain information from the power elements EL1-EL4 and the converters CON1-CON4 and exchange power between DC grids. Furthermore, because other distributed antennas that are not experiencing a failure are still operating, the power elements EL1-EL4 and the converters CON1-CON4 can be quickly restored to the wireless communication network by reconnecting them to the other distributed antennas that are not experiencing a failure.

[0053] Furthermore, in this embodiment, the MEC server 101 may acquire information on the power status (power generation capacity, power generation state, power storage capacity, power storage state, or power load) and electrical characteristic values ​​from other MEC servers 101 located nearby, and the EMS may control the power gate GA based on the acquired information so that power is shared among multiple DC grid groups located nearby. Such control for sharing power among multiple DC grid groups located nearby is an example of autonomous decentralized cooperative control.

[0054] However, the smoothing control of power supply and demand in the DC grids GR11 to GR44 installed within the communication area may not function effectively if the balance between power supply and demand exceeds a certain limit. For example, even if the MEC server 101 or the EMS operates the individual converters CON1 to CON4 in the DC grids GR11 to GR44 to smooth the power supply and demand, if the amount of power generation, power consumption, power load fluctuation, etc. that can be adjusted by the DC grids GR11 to GR44 is exceeded, power interchange beyond the range that the DC grids GR11 to GR44 can supply is required.

[0055] When the centralized control device 1000 determines that the autonomous distributed cooperative control is not functioning effectively, the power interchange is switched from the autonomous distributed cooperative control performed by the MEC server 101 or the EMS to centralized control in which the centralized control device 1000 controls the interchange of power between DC grid groups or between multiple DC grid groups that are nearby and other DC grid groups. In such centralized control, in the network system 1, the centralized control device 1000 controls the interchange of power from one of the communication areas CELL1 and CELL2 to the other. Specifically, when a power shortage occurs in a DC grid installed in the communication area CELL1 or CELL2, if a DC grid installed in one of the communication areas has excess power, the centralized control device 1000 controls the MEC server 101 of the base station 10A and the MEC server 101 of the base station 10B, so that power is interchanged from that DC grid to the DC grid that is experiencing the power shortage.

[0056] For example, the centralized control device 1000 acquires information such as power generation capacity, power generation state, power storage capacity, power storage state, and power load acquired by the MEC server 101 from the power elements EL1 to EL4, and information on electrical characteristic values ​​of the buses BUS acquired from the converters CON1 to CON4. The centralized control device 1000 identifies a DC grid that is short of power based on the acquired information, and instructs the MEC server 101 of the base station 10A and the MEC server 101 of the base station 10B to interchange power to the identified DC grid. In response to the instruction from the centralized control device 1000, the MEC server 101 of the base station 10A and the MEC server 101 of the base station 10B instruct the EMSs of the DC grids GR11 to GR44 under their jurisdiction to interchange power. The EMS controls, among the power gates GA within the communication area, the power gates GA on the path from the bus BUS of the DC grid that supplies power to the bus BUS of the DC grid that receives power. This makes it possible to achieve smoothing of power supply and demand even between DC grids installed in different communication areas.

[0057] According to this embodiment, even if a disaster causes a failure in the antenna ANT covering the area of ​​the DC grids GR11 to GR44, for example, by quickly installing a mobile base station that complements the wireless communication network, it is possible to restore the power elements EL1 to EL4 and the converters CON1 to CON4 included in the DC grids GR11 to GR44 to the wireless communication network, thereby enhancing resilience compared to the power network system disclosed in Patent Document 1. Furthermore, according to this embodiment, even if a disaster occurs, autonomous decentralized control is performed in each of the DC grids GR11 to GR44, so that the DC grids GR11 to GR44 can be operated. Furthermore, according to this embodiment, even if a disaster occurs, the base stations 10A and 10B and the DC grids GR11 to GR44 operate using storage batteries and power generation facilities, so that power interchange is possible within the communication area, thereby enhancing resilience compared to the power network system disclosed in Patent Document 1.

[0058] [Variations] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be implemented in various other forms. For example, the above-described embodiments may be modified as follows to implement the present invention. The above-described embodiments and the following modifications may be combined with each other. The present invention also includes configurations in which the components of the above-described embodiments and modifications are appropriately combined. Furthermore, further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspects of the present invention are not limited to the above-described embodiments and modifications, and various modifications are possible.

[0059] Fig. 7 is a diagram showing an example of the arrangement of a star-shaped DC grid. In the configuration shown in Fig. 7, buses BUS are arranged linearly with a length of 1 km and connected to branch lines BL, and DC grids GR1 to GR16 are formed by the buses BUS and branch lines BL. Each of the DC grids GR1 to GR16 is covered for wireless communication by a communication area formed by small cells along the buses BUS and branch lines BL. In the configuration shown in Fig. 7 as well, power gates GA are provided between the DC grids to exchange power between the DC grids. The power gates GA are connected to each other by cables. Each of the DC grids GR1 to GR16 is an example of a star-shaped DC grid.

[0060] FIG. 8 is a diagram showing an example of a star-shaped DC grid arrangement. In the configuration shown in FIG. 8, buses BUS are arranged in a star shape with an overall length of 1 km. In the configuration shown in FIG. 8, buses BUS are arranged in a 4-row, 4-column arrangement within a communication area CELL1 to form DC grids GR11 to GR44. Each of the DC grids GR11 to GR44 is covered by a communication area formed of 2-row, 2-column small cells. In the configuration shown in FIG. 8, a power gate GA is provided between the DC grids to exchange power between them. Each of the DC grids GR11 to GR44 shown in FIG. 8 is an example of a star-shaped DC grid. Note that in the configuration shown in FIG. 8, one power gate GA is provided for exchanging power with a DC grid in an adjacent communication area, but this is not limited to one. In the communication area CELL1, a power gate GA for exchanging power with the DC grid in the adjacent communication area may be provided in each of the buses BUS forming a DC grid adjacent to the DC grid in the adjacent communication area.

[0061] FIG. 9 is a diagram showing an example of the arrangement of a ring-shaped DC grid. In the configuration shown in FIG. 9, a bus BUS is arranged in a ring shape with an overall length of 1 km, and is connected to branch lines BL. In the configuration shown in FIG. 9, the bus BUS is arranged in 8 rows and 8 columns within a communication area CELL1 to form DC grids GR11 to GR84. Each of the DC grids GR11 to GR84 is covered by a communication area formed by small cells of 1 row and 2 columns, and wireless communication is covered. Each of the DC grids GR11 to GR84 shown in FIG. 9 is an example of a ring-shaped DC grid. In the configuration shown in FIG. 9, a power gate GA is provided between the DC grids to exchange power between the DC grids. Note that in the configuration shown in FIG. 9, one power gate GA is provided for exchange of power with a DC grid in an adjacent communication area, but the number of power gates is not limited to one. Within the communication area CELL1, a power gate GA for power interchange with the DC grid in the adjacent communication area may be provided on each bus BUS that forms a DC grid adjacent to the DC grid in the adjacent communication area.

[0062] Even in the configurations shown in Figures 7 to 9, each DC grid is controlled autonomously and decentralized, so that the DC grid can be operated even in the event of a disaster, allowing power interchange within the communication area. Also in this modification, even if a disaster causes a failure in the antenna ANT covering the DC grid area, the power elements EL1 to EL4 and converters CON1 to CON4 included in the DC grid can be quickly restored to the wireless communication network by, for example, installing a mobile base station that complements the wireless communication network. The layout of the bus BUS is not limited to the layout examples shown in the drawings, and may be a combination of the bent layout, linear layout, cross-shaped layout, and ring-shaped layout shown in Figures 3 and 7 to 9. For example, a mesh-type DC grid may be formed by combining a linear layout and a cross-shaped layout, or a mesh-type DC grid may be formed by combining linear layouts.

[0063] FIG. 10 is a diagram showing an example of the layout of a mesh-shaped DC grid. Bus BUS11 is a bus arranged in a star shape, and bus BUS12 is a bus arranged in a ring shape. Bus BUS11 and bus BUS12 are connected, and a pair of one bus BUS11 and one bus BUS12 forms one DC grid. Note that areas in FIG. 10 where bus BUS11 and bus BUS12 are not arranged are supplied with power from areas where bus BUS11 and bus BUS12 are located. For example, power is supplied to small cells SCEL13 and SCEL23 from bus BUS11 and bus BUS12 that form DC grid GR11, and power is supplied to small cells SCEL14 and SCEL24 from bus BUS11 and bus BUS12 that form DC grid GR13. In the configuration shown in FIG. 10 as well, power gates GA are provided between the DC grids to exchange power between the DC grids. Each of the DC grids shown in FIG. 10 is an example of a meshed DC grid.

[0064] FIG. 11 is a diagram showing another example of the layout of a mesh-shaped DC grid. Bus BUS11 is a bus arranged in a star shape, and bus BUS12 is a bus arranged in a ring shape. Bus BUS11 and bus BUS12 are connected, and a pair of one bus BUS11 and one bus BUS12 forms one DC grid. In the configuration shown in FIG. 11, bus BUS11 is arranged along the diagonal of bus BUS12. Note that, also in the configuration shown in FIG. 11, areas where buses BUS11 and BUS12 are not arranged are supplied with power from areas where buses BUS11 and BUS12 are located. For example, power is supplied to small cells SCEL13 and SCEL23 from bus BUS11 and bus BUS12 that form DC grid GR11, and power is supplied to small cells SCEL14 and SCEL24 from bus BUS11 and bus BUS12 that form DC grid GR13. In the configuration shown in Fig. 11, a power gate GA that exchanges power between the DC grids is also provided between the DC grids. Each of the DC grids shown in Fig. 11 is an example of a mesh-shaped DC grid.

[0065] In the above-described embodiment, the baseline length of the bus BUS is 1 km, but the baseline length is not limited to 1 km and may be shorter or longer than 1 km. Note that if the baseline length is not 1 km, the number of small cells covering the DC grid formed by the bus BUS will be a number corresponding to the baseline length.

[0066] In the above-described embodiment, the size of the communication area CELL1 and the communication area CELL2 is 1 km in radius, but the size of the communication area CELL1 and the communication area CELL2 is not limited to a 1 km radius and may be less than or greater than 1 km in radius. Also, in the above-described embodiment, the size of the small cells SCEL11 to SCEL88 is 125 m in radius, but the size of the small cells is not limited to a 125 m radius either and may be less than or greater than 125 m in radius.

[0067] In the above-described embodiment, at least one bus BUS in one communication area may be connected to the power system 3, and power may be supplied from or supplied to the power system 3.

[0068] In the above-described embodiment, the power elements EL1 to EL4 and the converters CON1 to CON4 may perform wireless communication with the base stations 10A and 10B when a failure occurs in the antenna ANT.

[0069] In the above-described embodiment, the bus BUS is connected to the power system 3 via a power converter that converts AC to DC, and in the above-described autonomous decentralized cooperative control or centralized control, the MEC server 101 and the centralized control device 1000 may control the power converter connected to the power system 3 so that power is supplied from the power system 3, in addition to exchanging power between DC grids. [Industrial Applicability]

[0070] The present invention can be used in an integrated power and communication network system. [Explanation of symbols]

[0071] 1 Network System 2. Cloud System 3 Power system 10A, 10B base station 101 MEC Server 102 AC / DC converter 103 Electricity storage device 104 CU / DU 111 Control Unit 112 Storage section 113 Communications Department 1000 Centralized control device ANT antenna BL branch line BUS, BUS1, BUS2, BUS3, BUS11, BUS12 buses CELL1, CELL2 communication area CON1~CON4 converter EL1~EL4 power elements GA, GA1, GA2 power gates GCON1 to GCON4 DC / DC converters GR1~GR10, GR11~GR44, GRmn DC grid SCEL11 to SCEL88 small cells

Claims

1. a plurality of wireless base stations that relay communications between wireless terminals; a plurality of distributed antennas connected to the radio base station, each of which forms a cell enabling communication with the radio terminal; a plurality of DC grids arranged in a predetermined form within a communication area formed by the plurality of cells, and exchanging power with a plurality of power devices connected thereto; a power gate provided between adjacent DC grids for transferring power between the DC grids; a control device provided for each of the wireless base stations, which controls the power gates based on information acquired from the power devices via the distributed antenna; a centralized control device that controls the plurality of control devices based on information acquired from the power devices; and the control device controls the power gates under control of the centralized control device to control power interchange between DC grids; The power devices connected to the DC grid communicate with the control device via the distributed antennas that form the communication area including the DC grid. Network system.

2. The DC grid is in the form of a bus. The network system according to claim 1 .

3. The DC grid has a star shape. The network system according to claim 1 .

4. The DC grid is in the form of a ring. The network system according to claim 1 .

5. The DC grid is in the form of a mesh. The network system according to claim 1 .

6. When the power gate interchanges power, it makes the voltage of the DC grid on the power supply side higher than the voltage of the DC grid on the power supply side. The network system according to any one of claims 1 to 5.

7. a plurality of wireless base stations that relay communications between wireless terminals; a plurality of distributed antennas connected to the radio base station, each of which forms a cell enabling communication with the radio terminal; a plurality of DC grids arranged in a predetermined form within a communication area formed by the plurality of cells, and exchanging power with a plurality of power devices connected thereto; a power gate provided between adjacent DC grids for transferring power between the DC grids; a control device provided for each of the wireless base stations, which controls the power gates based on information acquired from the power devices via the distributed antenna; a centralized control device that controls the plurality of control devices based on information acquired from the power devices; A control method for a network system having a step in which the control device acquires information transmitted from the electric power device via the distributed antenna; a step of controlling the power gates by the control device so that power is exchanged between the DC grids based on the acquired information; a step in which the control device controls the power gates under control of the centralized control device to control power interchange between DC grids; have A method for controlling a network system.

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