Power network and method for changing the same

Abstract

The power network comprises: a plurality of power routers having a plurality of power ports capable of inputting and outputting DC power, the power being converted from any one of the plurality of power ports and outputting the power from at least one other power port; a plurality of linkage lines connecting the plurality of power routers in a grid-like manner via the power ports; and a power device connected to at least one power port of the plurality of power routers not connected to the linkage line and consuming or supplying power, wherein at least one of the plurality of power ports of each of the plurality of power routers is set as a row port in which the characteristics of the DC power to be input or the DC power to be output are not controlled.

Description

Technical Field

[0001] The present invention relates to an electric power network and a method for changing the electric power network. Background Art

[0002] In recent years, the introduction of renewable energy power sources has been accelerating to address global warming. For example, at the 24th Conference of the Parties to the United Nations Framework Convention on Climate Change (COP24), global average temperature targets were set, and the introduction of renewable energy has become a global trend. On the other hand, due to frequency stabilization constraints, increasing the proportion of renewable energy sources that are highly variable and lack synchronous power sources (such as GF (no speed regulation) and LFC (load frequency control)) while maintaining the existing power system could potentially cause large-scale power outages and other problems.

[0003] Therefore, in recent years, technologies related to the introduction of renewable energy have been proposed (Patent Documents 1 and 2, Non-Patent Document 1). For example, Patent Document 1 or Non-Patent Document 1 proposes using multiple microgrids with local production and consumption as a foundation, asynchronously connecting these microgrids to accommodate excess or insufficient systems, and using power routers (so-called digital grid routers) as their equipment. This makes it possible to introduce large-scale renewable energy.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-061970

[0007] Patent Document 2: International Publication No. 2014 / 033892

[0008] Non-patent literature

[0009] Non-patent literature 1: Rikiya Abe, et al., "Digital Grid: Communicative Electrical Grids of the Future", IEEE Transactions on Smart Grid (Volume: 2, Issue: 2, June 2011) Summary of the Invention

[0010] -Problems to be solved by the invention-

[0011] In power networks, microgrids that include power sources utilizing renewable energy sources are sometimes connected to each other using direct current (DC) power paths in a tree-like configuration. However, with such tree-like connections, flexible power exchange between microgrids can be difficult. Furthermore, when working on power networks for expansion or to address outages, the work area is sometimes electrically isolated using switches, which can disrupt power network operations.

[0012] The present invention has been made in view of the above-mentioned situation, and an object of the present invention is to provide a power network suitable for flexible power supply switching and a method for changing the power network suitable for flexible power supply switching and capable of suppressing interruption of operation.

[0013] -Methods for solving the problem-

[0014] In order to solve the above-mentioned problems and achieve the objectives, one embodiment of the present invention involves a power network comprising: a plurality of power routers having a plurality of power ports capable of inputting and outputting DC power, converting power input from any one of the plurality of power ports and outputting it from at least one other power port; a plurality of linkage lines connecting the plurality of power routers in a grid-like manner via the power ports; and a power device consuming or supplying power, connected to at least one power port of the plurality of power routers that is not connected to the linkage lines, wherein at least one of the plurality of power ports of each of the plurality of power routers is set as a row port that does not control the characteristics of the input or output DC power.

[0015] At least one of the row ports may be connected to a power storage device capable of storing and releasing DC power.

[0016] Alternatively, at least one of the row ports of the plurality of power routers may be connected to a voltage constant control port among the plurality of power ports of at least one of the other power routers, wherein the voltage constant control port is configured as a port for controlling the voltage of the DC power input or output by the power router to be constant within a given range.

[0017] At least one of the row ports of the power router having the voltage constant control port connected to the row port may be connected to a power storage device capable of storing and releasing DC power.

[0018] Alternatively, at least one of the power ports of the multiple power routers may be a voltage-constant control port configured to control the voltage of the input or output DC power to be constant within a given range, and the voltage-constant control port may be connected to a current-constant control port of another power port of the multiple power ports of the power routers configured to control the current of the input or output DC power to be constant within a given range.

[0019] The device may further include a control unit that controls the operation of at least one of the plurality of power routers.

[0020] The control unit may alternately switch at least one power port of the at least one power router between the row port and a control port configured to control characteristics of input or output DC power.

[0021] Alternatively, the plurality of power ports of the at least one power router may be respectively connected to a plurality of power storage devices capable of storing and releasing DC power, and the control unit may alternately switch the power ports respectively connected to the plurality of power storage devices into row ports and control ports according to the respective charge states of the plurality of power storage devices.

[0022] The control unit may switch the power port connected to a power storage device whose indicator indicating a state of charge is close to an upper limit or a lower limit among the plurality of power storage devices from a row port to a control port.

[0023] The control unit may control operations of at least two of the plurality of power routers.

[0024] The control unit may stop the operation of the power router associated with the power port scheduled to be connected via the interlocking line among the power ports of the at least two power routers, and maintain the operation of the power router associated with the power port other than the scheduled connection.

[0025] Alternatively, when the power port scheduled for connection is a row port, the control unit may stop the operation of the power router associated with the row port and set at least one of the power ports other than the scheduled connection as a row port.

[0026] Alternatively, when it is determined that a fault has occurred in at least one of the plurality of linkage lines and the power port connected to the faulty linkage line is a row port, the control unit switches at least one of the other power ports of the power router having the row port to a row port.

[0027] The control unit may switch a power port of another power router connected to a linkage line connected to the power port switched to the row port to a voltage-constrained port when the power port is not a voltage-constrained port.

[0028] One embodiment of the present invention relates to a method for modifying a power network, the power network comprising: a plurality of power routers each having a plurality of power ports capable of inputting and outputting DC power, the power input from at least one of the plurality of power ports being converted and output from at least one other power port; a plurality of linkage lines connecting the plurality of power routers in a meshed manner via the power ports; and a power device consuming or supplying power, the device being connected to at least one power port of the plurality of power routers not connected to the linkage line, at least one of the plurality of power ports of each of the plurality of power routers being configured as a row port that does not control characteristics of DC power input or output; the method comprising: suspending operation of the power router associated with a power port that is scheduled to be connected via the linkage line, maintaining operation of the power router associated with power ports other than the scheduled connection, and connecting an additional power router to the scheduled connection power port via the linkage line.

[0029] If the power port scheduled for connection is a row port, the operation of the power router associated with the row port may be stopped, and at least one of the power ports other than the scheduled connection may be set as a row port.

[0030] One embodiment of the present invention relates to a method for changing a power network, the power network comprising: a plurality of power routers each having a plurality of power ports capable of inputting and outputting DC power, the power input from at least one of the plurality of power ports being converted and output from at least one other power port; a plurality of linkage lines connecting the plurality of power routers in a mesh configuration via the power ports; and a power device consuming or supplying power, the device being connected to at least one power port of the plurality of power routers not connected to the linkage line; at least one of the plurality of power ports of each of the plurality of power routers being configured as a row port that does not control characteristics of the DC power input or output; and when it is determined that a fault has occurred in at least one of the plurality of linkage lines and the power port connected to the faulty linkage line is a row port, at least one of the other power ports of the power router having the row port is switched to the row port.

[0031] When a power port of another power router connected to the interlocking line connected to the power port switched to the row port is not a voltage constant control port, the power port may be switched to a voltage constant control port.

[0032] One embodiment of the present invention relates to a method for modifying a power network, the power network comprising: a plurality of power routers each having a plurality of power ports capable of inputting and outputting DC power, the power input from at least one of the plurality of power ports being converted and output from at least one other power port; a plurality of linkage lines connecting the plurality of power routers in a mesh configuration via the power ports; and a power device consuming or supplying power, connected to at least one power port of the plurality of power routers not connected to the linkage line; at least one of the plurality of power ports of each of the plurality of power routers being configured as a row port that does not control the characteristics of the input or output DC power, and the plurality of power ports of the at least one power router being connected to a plurality of power storage devices capable of storing and releasing DC power, respectively; and the power ports connected to each of the plurality of power storage devices being alternately switched between the row port and the control port according to the charge state of each of the plurality of power storage devices.

[0033] The power port connected to a power storage device among the plurality of power storage devices whose indicator indicating the state of charge is close to an upper limit value or a lower limit value may be switched from a row port to a control port.

[0034] -Effects of the Invention-

[0035] According to the present invention, at least one of the multiple power ports of each of the multiple power routers is configured as a row port where the characteristics of the DC power being input or output are not controlled. As a result, the row port can be used to adjust the difference between the amount of power flowing into and out of the power router, thereby providing a power network suitable for flexible power supply switching. Furthermore, according to the present invention, at least one of the multiple power ports of each of the multiple power routers is configured as a row port where the characteristics of the DC power being input or output are not controlled, and the operation of the power router associated with the power port that is scheduled to be connected via a linkage line among the power ports of at least two of the multiple power routers is stopped, while the operation of the power router associated with the power port other than the scheduled connection is maintained, and the additional power router is connected to the power port that is scheduled to be connected via the linkage line. As a result, the row port can be used to adjust the difference between the amount of power flowing into and out of the power router, while the operation of the power router associated with the power port other than the scheduled connection is maintained, thereby providing a method for modifying a power network suitable for flexible power supply switching and minimizing operational interruptions. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1A It is a diagram illustrating components of a power network according to an embodiment.

[0037] Figure 1B It is a diagram for explaining another form of the components of the power network according to the embodiment.

[0038] Figure 2 This is a configuration diagram of a power network according to the first embodiment.

[0039] Figure 3 This is a configuration diagram of a power network according to the second embodiment.

[0040] Figure 4 This is a diagram showing the configuration of a power network according to the third embodiment.

[0041] Figure 5 This is an explanatory diagram of a method for expanding a power network according to a fourth embodiment.

[0042] Figure 6 It is an explanatory diagram of a method for expanding a power network according to the fifth embodiment.

[0043] Figure 7 This is an explanatory diagram of a method for expanding a power network according to a sixth embodiment.

[0044] Figure 8 This is an explanatory diagram of a method for operating a power network during a fault according to the seventh embodiment.

[0045] Figure 9 This is an explanatory diagram of a method for operating a power network during a fault according to the eighth embodiment.

[0046] Figure 10 It is an explanatory diagram of a method for switching settings of a power port according to the ninth embodiment.

[0047] Figure 11 This is an explanatory diagram of an example of loop control. DETAILED DESCRIPTION

[0048] Hereinafter, the embodiment will be described with reference to the accompanying drawings. In addition, the present invention is limited by the embodiment. In addition, in the description of the drawings, the same or corresponding elements are appropriately given the same reference numerals.

[0049] <Structural elements of the power network>

[0050] First, refer to Figure 1AThe components of the power network according to the embodiment will be described. The power network includes, for example, a microgrid 10 and a power router 21. The microgrid includes the power router 11, a tree-shaped DC bus 12, DC / DC converters 13a, 14a, 15a, 16a, and 17a, a DC / AC converter 18a, an EDLC (Electric Double-Layer Capacitor) 13b as a power device, batteries 14b, 15b, and 16b, a PV (Photovoltaic) device 17b, a load 18b, and an energy management system (EMS) 19.

[0051] <Structure of Power Router>

[0052] The power router 11 of this embodiment includes a plurality of, namely, three, power ports 11a1 , 11a2 , and 11a3 , three power measuring units 11b1 , 11b2 , and 11b3 , and a control unit 11c for controlling the operation of the power router 11 .

[0053] Power ports 11a1, 11a2, and 11a3 are power ports capable of inputting and outputting DC power. Power router 11 is an example of a power router that converts power input from any one of power ports 11a1, 11a2, and 11a3 and outputs power from at least one of the other power ports. Power router 11 can be configured using, for example, a self-excited power converter that performs bidirectional power conversion.

[0054] The power measuring units 11b1, 11b2, and 11b3 are measuring devices that measure characteristic values ​​related to the power flowing through the corresponding power ports 11a1, 11a2, and 11a3, respectively. The characteristic values ​​measured by the power measuring units 11b, 11b2, and 11b3 include, for example, voltage, current, power flow, and phase.

[0055] The control unit 11c can control the power converter and control the amount of power flowing through the power ports 11a1 and 11a2. The control unit 11c includes, for example, a calculation unit, a storage unit, and a communication unit.

[0056] The computing unit is a component that performs various computing processes to realize the functions of the control unit 11c, and is composed of, for example, a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), an FPGA (field-programmable gate array), a DSP (Digital Signal Processor), a GPU (Graphics Processing Unit), or a suitable combination thereof.

[0057] The storage unit includes, for example, a ROM (Read Only Memory) that stores various programs and data used by the computing unit for computing. Furthermore, the storage unit includes, for example, a RAM (Random Access Memory) that is used to store the workspace used by the computing unit for computing and the results of the computing unit's computing. The storage unit may also include an auxiliary storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). At least part of the functions of the control unit 11c are realized as a functional unit by the computing unit reading various programs from the storage unit and executing them.

[0058] The communication unit is configured to communicate with power measuring units 11b1, 11b2, and 11b3, and receive information on characteristic values ​​measured by power measuring units 11b1, 11b2, and 11b3. The received information is stored in the aforementioned storage unit. Furthermore, the communication unit is configured to communicate with EMS 19, receive control commands from EMS 19, and transmit information on the operating status of power router 11 or characteristic values ​​stored in the storage unit to EMS 19.

[0059] In the power router 11, the power port 11a1 is connected to the DC bus 12. The power port 11a2 is connected to the power port 21a of the power router 21 via the linkage line 101, which serves as a power path. The linkage line is sometimes referred to as an edge. The power router 21 has the same structure and function as the power router 11. The power port 11a3 is connected to the power port of a power router (not shown) via the linkage line 101. In addition to the power port 21a, the power router 21 also has power ports 21b and 21c. The power ports 21b and 21c are each connected to the power ports of other power routers via the linkage line 101. In other words, the multiple linkage lines 101 connect the multiple power routers 11, 21, and other power routers in a grid-like manner via the power ports. Furthermore, the power port 11a1 is a power port that is not connected to the linkage line.

[0060] In the power router 11, the power port 11a1 is set as a row port in which the characteristics of the input DC power or the output DC power are not controlled. The power port 11a2 is set as a voltage-constant control port in which the voltage of the input DC power or the output power is controlled to be constant. The power port 11a3 is set as a current-constant control port in which the current of the input DC power or the output power is controlled to be constant. The voltage-constant control port and the current-constant control port are examples of control ports in which the characteristics of the input DC power or the output DC power are controlled. In addition, the voltage or current may vary as long as it is within the allowable range. If the variation is within the allowable range, the voltage or current can be considered constant. The allowable range is set, for example, taking into account the safety or operational stability of the equipment included in the power network such as the power router.

[0061] Hereinafter, the row port may be referred to as a d (dependent) port, the constant voltage control port as a CV (Constant Voltage) port, and the constant current control port as a CC (Constant Current) port. In the figures, the symbols "d," "CV," and "CC" may be used to indicate the power port settings.

[0062] On the other hand, the power port 21a is set as a CC port in the power router 21. The power port of the power router is set as any one of a d port, a CV port, and a CC port.

[0063] The power routers 11 and 21 each have three power ports, but may also have four or more power ports.

[0064] <Elements Connected to the DC Bus 12>

[0065] Next, a description will be given of elements connected to the DC bus 12. These elements are connected to the power port 11a1 that is not connected to the interlocking line.

[0066] EDLC 13b is an electric double-layer capacitor, an example of a power device that supplies power and an example of a power storage device capable of storing and releasing DC power. The DC / DC converter 13a includes an input / output port 13a1 electrically connected to the DC bus 12 and an input / output port 13a2 electrically connected to the EDLC 13b. When actual DC power corresponding to the power storage capacity (charge capacity) of the EDLC 13b is input to input / output port 13a2, the DC / DC converter 13a converts this power into DC power of a constant voltage within a predetermined range and outputs it from input / output port 13a1 to the DC bus 12. Conversely, when constant DC power is input to input / output port 13a1 from the DC bus 12 within a predetermined range, the DC / DC converter 13a converts this power into actual DC power and outputs it from input / output port 13a2 to the EDLC 13b. Specifically, input / output port 13a1 is configured as a CV port, and input / output port 13a2 is configured as a D port.

[0067] Battery 14b is a lead-acid battery, an example of a power device that supplies electricity, and an example of a power storage device capable of storing and releasing DC power. The DC / DC converter 14a includes an input / output port 14a1 electrically connected to the DC bus 12, and an input / output port 14a2 electrically connected to the battery 14b. When actual DC power corresponding to the amount of power stored (charged) in the battery 14b is input to input / output port 14a2, the DC / DC converter 14a converts this power into DC power of a constant voltage within a predetermined range, and outputs it from input / output port 14a1 to the DC bus 12. Conversely, when constant DC power is input to input / output port 14a1 from the DC bus 12 within a predetermined range, the DC / DC converter 14a converts this power into actual DC power, and outputs it from input / output port 14a2 to the battery 14b. Specifically, input / output port 14a1 is configured as a CV port, and input / output port 14a2 is configured as a D port.

[0068] Battery 15b is a lithium-ion battery and is an example of a power device that supplies power, and is also an example of a power storage device that can store and release DC power. DC / DC converter 15a includes input / output port 15a1 electrically connected to DC bus 12 and input / output port 15a2 electrically connected to battery 15b. DC / DC converter 15a is a DC / DC converter in which input / output port 15a1 is a CV port and input / output port 15a2 is a D port.

[0069] Battery 16b is a lithium-ion battery and is an example of a power device that supplies power. It is also an example of a power storage device that can store and release DC power. DC / DC converter 16a includes input / output port 16a1 electrically connected to DC bus 12 and input / output port 16a2 electrically connected to battery 16b. DC / DC converter 16a is a DC / DC converter in which input / output port 16a1 is a CV port and input / output port 16a2 is a D port.

[0070] Furthermore, the batteries 14b, 15b, and 16b may be mounted on an electric vehicle or a hybrid vehicle.

[0071] Furthermore, the EDLC 13b and batteries 14b, 15b, and 16b may also include a known BMS (Battery Management System) that acquires information related to the charging status, such as voltage and temperature. The BMS may be configured, for example, to include sensors, a microcomputer, and an input / output interface. The BMS transmits the acquired charging status information to a connected DC / DC converter or an EMS (described later). The BMS may be located external to the EDLC 13b and batteries 14b, 15b, and 16b, or may be included in its own connected DC / DC converter.

[0072] PV device 17b is an example of an electric power device that uses solar power to supply electricity (generates electricity). Since the power generation of PV device 17b varies depending on meteorological conditions, the optimal operating point at which the output power is maximized also varies. DC / DC converter 17a includes input / output port 17a1 electrically connected to DC bus 12 and input / output port 17a2 electrically connected to PV device 17b. When actual DC power corresponding to the power generation of PV device 17b is input to input / output port 17a2, DC / DC converter 17a performs MPPT (Maximum Power Point Tracking) control, that is, the operating point is tracked so that the output power is maximized using the power generation. DC / DC converter 17a outputs actual DC power corresponding to the maximum output power from input / output port 17a1 to DC bus 12. In other words, input / output port 17a1 is set as a d-port.

[0073] Load 18b is an example of an electric power device that consumes AC power. The DC / AC converter 18a includes an input / output port 18a1 electrically connected to the DC bus 12 and an input / output port 18a2 electrically connected to the load 18b. When DC power of a constant voltage is input from the DC bus 12 to input / output port 18a1 within a predetermined range, the DC / AC converter 18a converts this power into AC power of a constant voltage within a predetermined range and outputs it from input / output port 18a2 to the load 18b. Load 18b operates using this AC power. Specifically, input / output port 18a2 is configured as a d-port, and is configured as a constant power control port.

[0074] The EMS 19 is a system that comprehensively manages the status of the microgrid 10. The EMS 19 controls the DC / DC converters 13a, 14a, 15a, 16a, and 17a, and the DC / AC converter 18a, controlling the current, voltage, or power input and output to these devices. Furthermore, the DC / DC converters 13a, 14a, 15a, 16a, 17a, and the DC / AC converter 18a, acting as power converters, each include a power meter similar to the power meter 11b1, which measures characteristic values ​​related to power for control purposes. These units are configured to communicate information regarding these measurement results to the EMS 19. Based on this information, the EMS 19 controls the operation of each power converter. Furthermore, the EMS 19 receives information about the power router 11's operating status or the characteristic values ​​stored in its storage unit from the power router 11's control unit 11c, and based on this information, sends control commands to the control unit 11c. In other words, the EMS 19 can control the operation of the power router 11. Furthermore, the EMS 19 may be configured to be able to communicate with the EMSs of other microgrids. In this case, the EMS 19 may also be able to control the operations of at least two of the power routers 11 and the power routers of the other microgrids.

[0075] The EMS 19, for example, similar to the control unit 11c, includes a computing unit, a storage unit, and a communication unit. The computing unit includes a CPU, an ASIC, an FPGA, a DSP, a GPU, or a suitable combination thereof, which performs the various computing processes required to implement the functions of the EMS 19. The storage unit includes a ROM for storing various programs and data used by the computing unit for computing processes, a RAM for storing the computing unit's workspace during computing processes and the results of the computing unit's computing processes, and may also include an auxiliary storage device such as an HDD or SSD. At least part of the functions of the control unit are implemented as a functional unit by the computing unit reading and executing various programs from the storage unit.

[0076] Figure 1BFIG. 1 is a diagram illustrating another embodiment of the electric power network. Figure 1B In the embodiment, the microgrid 10 shown in FIG. 1 is replaced with a microgrid 10A.

[0077] The microgrid 10A has a configuration in which the DC bus 12 is replaced with a DC bus 12A, the DC / DC converter 14a is replaced with a DC / DC converter 14Aa, and a DC / AC converter 31 is added to the configuration of the microgrid 10 .

[0078] The DC / AC converter 31 electrically connects its DC-side input / output port 31a to the DC bus 12, and its AC-side input / output port 31b to the power company's power grid 32. When actual AC power is input from the power grid 32 to input / output port 31b, the DC / AC converter 31 converts it into DC power with a constant voltage within a predetermined range and outputs it from input / output port 31a to the DC bus 12A. Furthermore, when DC power with a constant voltage is input from the DC bus 12A to input / output port 31a within a predetermined range, the DC / AC converter 31 converts it into actual AC power and outputs it from input / output port 31b to the power grid 32. Specifically, input / output port 31a is configured as a CV terminal port, and input / output port 31b is configured as a D port. This allows the microgrid 10A to receive power from the power grid 32 and output power to the power grid 32 (e.g., sell power).

[0079] Furthermore, in microgrid 10A, DC / DC converter 14Aa includes an input / output port 14Aa1 electrically connected to DC bus 12A and an input / output port 14Aa2 electrically connected to battery 14b. When DC power with a constant current within a predetermined range is input from battery 14b to input / output port 14Aa2, DC / DC converter 14Aa converts this power into actual DC power and outputs it from input / output port 14a1 to DC bus 12A. Conversely, when actual DC power is input from DC bus 12A to input / output port 14Aa1, DC / DC converter 14Aa converts this power into a constant current within a predetermined range and outputs it from input / output port 14Aa2 to battery 14b. Specifically, input / output port 14Aa1 is configured as a d-port, and input / output port 14Aa2 is configured as a CC-port.

[0080] Based on the above description of the components, each embodiment will be described.

[0081] (Implementation 1)

[0082] Figure 21 is a diagram showing the structure of a power network according to Embodiment 1. The power network 100 includes a plurality of nodes having a plurality of power ports and a plurality of interconnection lines connecting these nodes in a mesh shape via the power ports. Figure 2 , denoted by , among the plurality of nodes, are nodes N1 and N2, and denoted by , among the plurality of linkage lines, are power paths P1, P2, P3, P4, P5, and P6.

[0083] Nodes N1 and N2 are respectively composed of Figure 1A 1B , such as microgrids 10 and 10A shown in FIG1B , which include a power router, a DC bus, and various power devices. Among the multiple nodes in power network 100 , some may consist solely of power routers. That is, each node includes a power router.

[0084] The power ports T11, T12, and T13 of the power router at node N1 are configured as a CV port, a D port, and a CC port, respectively. The power ports T21, T22, T23, and T24 of the power router at node N2 are configured as a D port, a CV port, a CC port, and a CC port, respectively. Furthermore, the power port types of the nodes can be switched between each other under the control of the control unit of the power router.

[0085] Power path P1 connects the CV port of node N1, i.e., power port T11, to power port T21 of node N2. Power path P2 connects power port T12 of node N1 to power ports of other nodes. Power path P3 connects power port T13 of node N1 to power ports of other nodes. Power path P4 connects power port T22 of node N2 to power ports of other nodes. Power path P5 connects power port T23 of node N2 to power ports of other nodes. Power path P6 connects power port T24 of node N2 to power ports of other nodes.

[0086] Each node sets at least one of the plurality of power ports as a d-port. In addition, one end of each linkage line is connected to the CV port, and the other end of each linkage line is connected to the d-port or the CC port.

[0087] In this way, in power network 100, since at least one of the multiple power ports at each node is configured as a d-port, the difference between the amount of power flowing in and out of each node can be adjusted at the d-port. In this case, the d-port functions as a buffer. For example, at node N1, when power flows out from power ports T11 and T13, an amount of power equal to the sum of the outflows flows into the d-port. Furthermore, when a first amount of power flows out from power port T11 and a second amount of power, which is greater than the first amount, flows into power port T13, an amount of power equal to the difference between the second and first amounts flows out from the d-port. As a result, power network 100 achieves a network structure suitable for flexible power switching utilizing d-ports. Furthermore, one end of each linkage line is connected to a CV port. This stabilizes the voltage of the power flowing in and out of the linkage line. Furthermore, if the other end of the linkage line is connected to a CC port, the power flow is controlled simultaneously with the voltage, thus achieving a more optimally controlled linkage line.

[0088] (Implementation Method 2)

[0089] Figure 3 This is a diagram illustrating the configuration of a power network according to Embodiment 2. Power network 200 includes: a plurality of nodes N3, N4, N5, N6, N7, N8, and N9; power paths P7, P8, P9, P10, P11, P12, P13, P14, P15, P16, P17, P18, P19, P20, P21, P22, and P23; and batteries B3, B4, B5, B6, B7, B8, and B9.

[0090] Node N3 has power ports T31, T32, T33, and T34, which are sequentially configured as a d-port, a CV-port, a CC-port, and a CC-port. Node N4 has power ports T41, T42, T43, and T44, which are sequentially configured as a d-port, a CV-port, a CV-port, and a CC-port. Node N5 has power ports T51, T52, T53, and T54, which are sequentially configured as a CV-port, a CC-port, a d-port, and a CC-port.

[0091] Node N6 has power ports T61, T62, T63, T64, and T65, which are sequentially configured as a CV port, a CV port, a CV port, a CV port, and a d port. Node N7 has power ports T71, T72, T73, and T74, which are sequentially configured as a CC port, a CV port, a d port, and a CV port. Node N8 has power ports T81, T82, and T83, which are sequentially configured as a CC port, a d port, and a CC port. Node N9 has power ports T91, T92, and T93, which are sequentially configured as a CC port, a CC port, and a d port.

[0092] Batteries B3 , B4 , B5 , B6 , B7 , and B8 are examples of power storage devices capable of storing and releasing DC power.

[0093] Power path P7 is a linkage line connecting the CV port of node N3, or power port T32, and the CC port of node N4, or power port T44. Therefore, power path P7 is a linkage line in which both voltage and power flow are controlled. Linkage lines such as those described above are sometimes referred to as control linkage lines. Power path P8 connects battery B3 to the d port of node N3, or power port T31. Power path P9 connects the CC port of node N3, or power port T33, and the CV port of node N5, or power port T51. It is a control linkage line in which both voltage and power flow are controlled. Power path P10 connects the CC port of node N3, or power port T34, and the CV port of node N6, or power port T61. It is a control linkage line in which both voltage and power flow are controlled.

[0094] Power path P11 connects battery B4 to the d-port of node N4, or power port T41. Power path P12 connects the CV port of node N4, or power port T42, to the CC port of node N8, or power port T81, and is a control linkage line for controlled voltage and power flow. Power path P13 connects the CV port of node N4, or power port T43, to the CC port of node N5, or power port T52, and is a control linkage line for controlled voltage and power flow.

[0095] Power path P14 connects battery B5 to the d-port of node N5, or power port T53. Power path P15 connects the CC port of node N5, or power port T54, to the CV port of node N6, or power port T62, and is a control linkage line in which voltage and power flow are controlled. Power path P16 connects the CV port of node N6, or power port T63, to the CC port of node N7, or power port T71, and is a control linkage line in which voltage and power flow are controlled. Power path P17 connects the CV port of node N6, or power port T64, to the CC port of node N9, or power port T91, and is a control linkage line in which voltage and power flow are controlled.

[0096] Power path P18 connects battery B6 to power port T65, the d port of node N6. Power path P19 connects power port T72, the CV port of node N7, to power port T83, the CC port of node N8, and is a control linkage line where voltage and power flow are controlled.

[0097] Power path P20 connects battery B7 to the d-port of node N7, power port T73. Power path P21 connects the CV port of node N7, power port T74, and the CC port of node N9, power port T92, serving as a control linkage line for voltage and power flow control. Power path P22 connects battery B8 to the d-port of node N8, power port T82. Power path P23 connects battery B9 to the d-port of node N9, power port T93.

[0098] In power network 200, the voltage and power flow of all power paths P7, P9, P10, P12, P13, P15, P16, P17, P19, and P21, which serve as interconnected lines, are controlled. Furthermore, each of nodes N3, N4, N5, N6, N7, N8, and N9 has a buffer connected to its d-port, namely, storage batteries B3, B4, B5, B6, B7, B8, and B9. This allows for adjustments to be made to the difference between inflow and outflow of power at each node, resulting in a flexible network structure capable of arbitrary power flow across all interconnected lines.

[0099] (Implementation 3)

[0100] Figure 4 2 is a diagram showing the structure of a power network according to Embodiment 3. The power network 200A has Figure 3 The illustrated configuration of the power network 200 removes batteries B3, B4, B8, and B9, and replaces power paths P7, P10, P12, and P17 with P7A, P10A, P12A, and P17A, respectively. Furthermore, the connection destinations of some power ports at nodes N3, N4, N8, and N9 have been changed.

[0101] Specifically, at node N3, power port T31, designated as the d-port, is connected to power path P10A. As a result, power path P10A is connected at one end to the d-port and at the other end to the CV port of node N6, namely power port T61. Therefore, this is not a linkage line in which both voltage and power flow are controlled. Such linkage lines are sometimes referred to as non-controlled linkage lines. In the figure, non-controlled linkage lines are represented by dashed lines.

[0102] Furthermore, at node N4, power port T41, which is set as the d-port, is connected to power path P7A. Consequently, power path P7A is a non-controlled interlocking line having one end connected to the d-port and the other end connected to power port T32, which is the CV port of node N3.

[0103] Furthermore, at node N8, power port T82, which is set as the d-port, is connected to power path P12A. Consequently, power path P12A is a non-controlled interlocking line with one end connected to the d-port and the other end connected to power port T42, which is the CV port of node N4.

[0104] Furthermore, at node N9, power port T93, which is set as the d-port, is connected to power path P17A. Consequently, power path P17A is a non-controlled interlocking line with one end connected to the d-port and the other end connected to power port T64, the CV port of node N6.

[0105] In power network 200A, nodes N5, N6, and N7, each having a d-port and a CV port connected by a tie line, have their d-ports connected to batteries B5, B6, and B7, respectively. Although none of the tie lines in power network 200A are control tie lines, by connecting the d-ports of nodes whose batteries have been removed (for example, the d-port of node N9) with the CV ports of nodes whose batteries have not been removed (for example, the CV port of node N6), a network structure is achieved that allows for flexible power supply exchange while reducing the number of batteries.

[0106] (Implementation 4)

[0107] Next, as an example of a method for changing a power network, a method for expanding a power network will be described. Figure 5 This is an explanatory diagram of a method for expanding a power network according to a fourth embodiment. Figure 5 The power network 300 shown has Figure 2 In the illustrated structure of power network 100, node N2 is replaced with node N10. Node N10 has power ports T101, T102, T103, and T104. Power port T101 is a CC port, connected to power port T11, the CV port of node N1, via power path P1. Power port T102 is a CV port, connected to other nodes via power path P31. Power port T103 is a CC port, connected to other nodes via power path P32. Power port T104 is a D port, connected to other nodes via power path P33.

[0108] To expand the power network 300, simply connect the power port T111 of node N11 to an unused power port T14 of node N1 via power path P14. By configuring one of power port T14 and power port T111 as a CV port and the other as a CC port, power path P14 can be used as a control linkage line. Furthermore, expansion can be performed without interrupting the operation of the other power ports T11, T12, and T13 of node N1.

[0109] (Implementation 5)

[0110] Figure 6 It is an explanatory diagram of a method for expanding a power network according to the fifth embodiment. Figure 6 The power network 300A shown has Figure 5 The illustrated power network 300 is configured with an EMS 310 that can control the operation of all nodes. The EMS 310 described above is sometimes referred to as a central EMS.

[0111] In power network 300A, a new node is added between node N1 and node N10. In this case, EMS 310 first stops the operation of node N1 and node N10 associated with power ports T11 and T101, which are scheduled to be connected by a linkage line among the power ports of node N1 and node N10, and maintains the operation of node N1 and node N10 associated with power ports other than the scheduled connection.

[0112] Next, power path P1 is removed, and power port T121 of the added node N12 is connected to power port T11 using power path P41 as a linkage line. Power port T122 is also connected to power port T101 using power path P42 as a linkage line. Node N12's other power port T123 can also be connected to other nodes via power path P43. Furthermore, the power ports connected to power paths P41, P42, and P43 are configured so that one is a CV port and the other is a CC port or a D port. EMS 310 then resumes the stopped operations of nodes N1 and N10, resuming the operation of node N12.

[0113] According to this method, the nodes N1 and N10 only stop operations related to the power ports to be connected and maintain operations related to other power ports. This allows expansion work to be performed while suppressing the degree of interruption of the operation of the power network 300A.

[0114] (Implementation 6)

[0115] Figure 7 This is an explanatory diagram of a method for expanding a power network according to a sixth embodiment. Figure 7 The power network 100A shown has Figure 2 The illustrated power network 100 is additionally configured with an EMS 110 capable of controlling the operations of all nodes.

[0116] In power network 100A, suppose a new node is added between nodes N1 and N2. In this case, EMS 110 first halts the operation of nodes N1 and N2 associated with power ports T11 and T21, which are scheduled to be connected via a linkage line, among their respective power ports. It then maintains the operation of nodes N1 and N2 associated with power ports not scheduled to be connected. Since power port T21 is set as a d-port, halting operation eliminates the d-port of node N2. Therefore, before halting the operation of node N2 associated with power port T21, EMS 110 confirms the existence of power ports other than the scheduled connection of node N2, namely, the power ports set as CC ports. Here, since power ports T23 and T24 are CC ports, for example, a decision is made to change power port T24 to a d-port.

[0117] Next, power path P1 is removed, and power port T131 of the added node N13 is connected to power port T11 using power path P51 as a linkage line. Power port T132 is connected to power port T21 using power path P52 as a linkage line. Node N13's other power port T133 can also be connected to other nodes via power path P53. EMS 110 then resumes the stopped operations of nodes N1 and N2 and restarts the operation of node N13.

[0118] According to this method, for nodes N1 and N2, only operations related to the power ports scheduled for connection are stopped, while operations related to the other power ports are maintained. This allows expansion work to be carried out while minimizing interruptions to the operation of the power network 100A. Furthermore, since a d port is secured for node N2, flexible power supply switching within the power network 100A can be maintained.

[0119] Furthermore, in this method, power ports set as CC ports are changed to D ports. In contrast, if all power ports other than those intended for connection are CV ports, the EMS appropriately selects any CV port, changes the power port of the node connected to that CV port via the interlocking line to a CV port, and then changes the selected CV port to a D port. This ensures that one of the interlocking lines is connected to a CV port.

[0120] (Implementation 7)

[0121] Next, as an example of a method for changing the electric power network, a method for operating the electric power network during a failure will be described. Figure 8 This is an explanatory diagram of a method for operating a power network during a fault according to the seventh embodiment. Figure 8 The power network 200B shown has Figure 4The illustrated power network 200A has an additional configuration of an EMS 210 capable of controlling the operations of all nodes.

[0122] like Figure 8 As shown, a disconnection occurs in power path P17A, which is a linkage line connecting the CV port (power port T64) of node N6 and the d port (power port T93) of node N9. If a disconnection occurs, EMS 210 detects the disconnection based on measurement results transmitted from the control unit of the power router included in each of nodes N6 and N9. Alternatively, a configuration may be employed in which, if a disconnection occurs, the control unit of each of the power routers included in nodes N6 and N9 transmits information indicating the disconnection to EMS 210.

[0123] Upon detecting a line break, EMS 210 halts the operation of node N6 associated with power port T64 connected to power path P17A and the operation of node N9 associated with power port T93. Before halting the operation of node N9 associated with power port T93, EMS 210 determines that power port T93 is a d-port and sends a control command to node N9 to switch the port type, switching power port T92, which was previously set as a CC port, to a d-port. This ensures that a d-port is available at node N9. Furthermore, switching power port T92 to a d-port changes power path P20, which connects power port T92 and power port T74 of node N7, from a controlled interlocking line to a non-controlled interlocking line.

[0124] According to this method, it is possible to maintain flexible power supply exchange in the power network 200B while suppressing the degree of interruption of operations.

[0125] (Implementation 8)

[0126] Figure 9 This is an explanatory diagram of a method for operating a power network at the time of a failure according to Embodiment 8. This embodiment will also be described with reference to the power network 200B, similarly to Embodiment 7.

[0127] like Figure 9 As shown, a disconnection occurs in power path P7A, which is a linkage line connecting the CV port (power port T32) of node N3 and the d port (power port T41) of node N4. If a disconnection occurs, EMS 210 detects the disconnection based on measurement results sent from the control unit of the power router included in each of nodes N3 and N4. Alternatively, if a disconnection occurs, the control unit of the power router included in each of nodes N3 and N4 may transmit disconnection information to EMS 210.

[0128] When a line break is detected, EMS210 stops the operation of node N3 related to power port T32 connected to power path P7A and the operation of node N4 related to power port T41. Before stopping the operation of node N4 related to power port T41, EMS210 determines that power port T41 is a d port. In addition, EMS210 also confirms that the power ports other than power port T41 in node N4 are CV ports. Then, a control instruction is sent to node N4, and a control instruction (port type switching (1)) is sent to the control unit of the power router of node N4 in order to execute port type switching of switching the power port set as a CV port, for example, power port T43, to a d port. As a result, the d port can be ensured at node N4. When the switching is completed, the control unit of the power router of node N4 notifies EMS210 of the completion.

[0129] On the other hand, before switching the power port T43 to the d port, EMS210 confirms the type of other power ports connected to the power path P13 connected to the power port T43. In this example, the power port of the connection destination of the power path P13 is the power port T52 of the node N5, which is set to a CC port. In this case, EMS210 determines that the power port T52 is not a CV port, and in order to execute the port type switch to switch the power port T52 to a CV port, it sends a control instruction (port type switch (2)) to the control unit of the power router of the node N5. When the switch is completed, the control unit of the power router of the node N5 notifies the EMS210 of the completion. After receiving the notification of the completion, EMS210 executes the switch of the power port T43 to the d port. As a result, the power path P13 is changed to a non-controlled linkage line, but since one side is connected to the CV port, the voltage is controlled to be constant.

[0130] According to this method, it is possible to maintain flexible power supply exchange in the power network 200B while suppressing interruptions in operation. In addition, it is possible to ensure that the voltage of the interlocking line is controlled to a constant state.

[0131] Furthermore, the operation method in case of a fault according to the seventh and eighth embodiments is not limited to a line break, but can be applied to various faults such as a short circuit and a ground fault.

[0132] (Implementation 9)

[0133] Next, as an example of a method for changing the power network, a method for switching the settings of the power port according to the charging state of the power storage device will be described. Figure 10 It is an explanatory diagram of a method for switching settings of a power port according to the ninth embodiment. Figure 10The power network 400 shown is similar to the power network of the first embodiment and includes a plurality of nodes having a plurality of power ports and a plurality of linkage lines connecting these nodes in a mesh shape via the power ports. Figure 10 Nodes N21 and N22 are shown among the multiple nodes, and power paths P61, P62, P63, P64, P65, and P66 are shown among the multiple interconnection lines. Furthermore, power network 400 includes batteries B21 and B22 and an EMS 410 capable of controlling the operation of all nodes. Batteries B21 and B22 are equipped with a BMS. Batteries B21 and B22 are examples of multiple power storage devices. Batteries B21 and B22 are examples of power storage devices, such as lithium-ion batteries.

[0134] Power path P61 connects power port T211 of node N21 to power port T223 of node N22. Power path P62 connects power port T212 of node N21 to battery B21. Power path P63 connects power port T213 of node N21 to power ports of other nodes. Power path P64 connects power port T221 of node N22 to battery B21. Power path P65 connects power port T222 of node N22 to power ports of other nodes. Power path P66 connects power port T224 of node N22 to power ports of other nodes.

[0135] In the power network 400 , the EMS 410 switches the power ports T212 and T221 connected to the batteries B21 and B22 to be d-ports and control ports, respectively, according to the charge states of the batteries B21 and B22 .

[0136] For example, the power port T212 is Figure 10 The setting of the CC port shown in the figure on the upper side is switched to the setting of the d port shown in the figure on the lower side. In addition, the power port T212 is switched from the setting of the d port to the setting of the CC port. In addition, the power port T221 is switched from the setting of the Figure 10 The D-port setting (shown in the upper diagram) is switched to the CC-port setting (shown in the lower diagram). Furthermore, power port T221 is switched from the CC-port setting to the D-port setting. EMS 410 obtains the charge status from information related to the charge status of batteries B21 and B22 obtained by the BMS and performs these switching operations based on the obtained charge status. The charge status is obtained by calculations performed by the calculation unit or by referencing table data stored in the storage unit. The referenced table data stores the correspondence between information related to the charge status and the charge status.

[0137] The method of the ninth embodiment is described below using a specific example. Figure 10In the diagram shown above, battery B22 is connected to the D port, functioning as a buffer. Battery B21 is connected to the CC port. In this state, battery B22 has a low regulation capability, while battery B21 has a high regulation capability.

[0138] Here, regulation capability refers to the degree of buffer functionality, with greater regulation capability indicating higher buffer functionality. For example, if the SoC (State of Charge), an example of a state of charge indicator, is close to an upper limit (e.g., 100%), the battery's function as a discharge buffer, discharging power, is high, and therefore, the regulation capability is high. If the SoC is close to a lower limit (e.g., 0%), the battery's function as a charge buffer, charging power, is low, and therefore, the regulation capability is low. Furthermore, if the SoC is outside the upper or lower limit (e.g., around 50%), the battery's function as both a discharge and charge buffer is relatively high. In this embodiment, EMS 410 determines that a battery with an SoC outside the upper or lower limit, for example, closer to 50%, has greater regulation capability. Furthermore, EMS 410 determines that a battery with an SoC closer to either the upper or lower limit, for example, further from 50%, has less regulation capability.

[0139] If EMS 410 determines, based on the SoC obtained from the BMS information, that the regulation capability of battery B22 is lower than that of battery B21 (the SoC is approaching the upper or lower limit), it switches power port T221 connected to battery B22 from a D-port to a CC-port, and switches power port T212 connected to battery B21 from a CC-port to a D-port. Furthermore, since this switching is performed while maintaining the buffer function of at least one of batteries B21 and B22, power port T221 may be switched to a CC-port after power port T212 is switched to a D-port.

[0140] In addition, Figure 10 In the case of the figure on the upper side, when the power port T221 in the node N22 is a d port, the power ports T222, T223, and T224 are CV port, CV port, and CC port respectively. In this case, if the power port T221 is switched to a CC port, the d port of the node N22 will disappear. Therefore, in order to maintain the existence of the d port, the power port T221 can also be switched to a CC port after switching the power port T223 from a CV port to a d port. In addition, Figure 10In the case of the upper diagram, when power port T212 at node N21 is a CC port, power ports T211 and T213 are d-port and CV ports, respectively. In this case, if power port T223 at node N22 is switched to a d-port, the voltage stability of power path P61, which serves as the linkage line, may be reduced. Therefore, to ensure the voltage stability of power path P61, power port T223I may be switched to a d-port after power port T211 is switched from a d-port to a CV port.

[0141] Therefore, an example of the order of switching the power ports is as follows. First, power port T212 is switched to a D port. Next, power port T211 is switched to a CV port. Next, power port T223 is switched to a D port. Next, power port T221 is switched to a CC port.

[0142] According to the method according to the ninth embodiment, it is possible to maintain flexible power supply exchange in the power network 400 while increasing the regulation capability of the battery, which is a power storage device, as a buffer.

[0143] Furthermore, in the method according to Embodiment 9, EMS 410 determines batteries B21 and B22 whose SoCs are far from their upper and lower limits as having high regulation capabilities, and batteries whose SoCs are close to their upper or lower limits as having low regulation capabilities. However, the criteria for determining regulation capabilities are not limited to this. For example, EMS 410 may also determine batteries B21 and B22 whose remaining capacities are far from their maximum and minimum capacities as having high regulation capabilities. In this case, the remaining capacity of the battery serves as an indicator of the state of charge. For example, if batteries B21 and B22 have different maximum capacities, the remaining capacity of the battery may be used as a more appropriate indicator of the state of charge. Furthermore, if there are multiple batteries, the power port connected to the battery with the lowest regulation capability may be switched from a D-port to a CC-port, or the power ports connected to two or more batteries whose regulation capabilities, determined based on an indicator indicating the state of charge, are lower than a predetermined standard, may be switched from D-ports to CC-ports.

[0144] Furthermore, the conditions for determining whether to switch the power port connected to the battery from the D-port to the CC-port are not limited to those described above. For example, the EMS 410 may also implement control such that, if the SoC of the battery connected to the power port serving as the D-port is determined to be within a predetermined range, the D-port setting is maintained, and if it is determined to be outside the predetermined range, the power port is switched to the CC-port. For example, the predetermined range may have a lower limit of 20% or 30% and an upper limit of 70% or 80%, but this range may vary depending on the battery. Furthermore, the conditions are not limited to the SoC; control may also be implemented to determine whether the remaining capacity is within or outside a predetermined range.

[0145] Furthermore, EMS 410 may also obtain power generation and demand forecast information for power grid 400 from other EMSs or external servers. This power generation and demand forecast information includes forecast information on power generation or power demand within power grid 400. For example, if power grid 400 includes photovoltaic (PV) installations, this information may also include information such as the season, current weather, and future weather forecasts for the region where the PV installations are installed. Furthermore, if power grid 400 includes batteries installed in electric vehicles (EVs, hybrid vehicles, etc.), this information may also include information on the power supply and demand of these electric vehicles.

[0146] EMS 410 can also change the criteria used to determine the level of regulation capacity based on the power generation / demand forecast information it obtains. For example, if information indicates that power generation is predicted to increase in the future, a battery with a SoC closer to the lower limit value can be determined as having higher regulation capacity, since the amount of power expected to be charged to the buffer is greater. Alternatively, if information indicates that power demand is predicted to increase in the future, a battery with a SoC closer to the upper limit value can be determined as having higher regulation capacity. Such changes to the EMS 410's criteria can be performed, for example, by calculations performed by the calculation unit or by reference to table data stored in the storage unit.

[0147] Furthermore, the EMS 410 may also change a given range related to an indicator (eg, SoC) set for switching power ports based on the obtained power generation / demand forecast information.

[0148] Furthermore, in the method according to the ninth embodiment, the power port connected to the battery is switched between the d port and the CC port, but may be switched between the d port and the CV port as the control port.

[0149] Furthermore, in the method according to Embodiment 9, the power port settings are switched based on the charge status of the storage batteries B21 and B22 connected to the power routers at each node. However, in other embodiments, the power port settings may be switched based on the charge status of the multiple storage batteries connected to each of the multiple power ports of the power router at the same node.

[0150] In addition, Figure 1A 、 1B In the embodiment, the input / output port set as the CV port (for example, the input / output port 15a1) may be cyclically controlled so that the relationship between the voltage on the DC bus 12 side and the power to be input / output follows a reference function having a predetermined droop characteristic. Here, the "droop characteristic" means a droop characteristic, which is a characteristic in which the relationship between the voltage and the power input / output has a relationship in which the power input / output is constant over a predetermined voltage range, or a relationship other than a relationship in which the voltage is constant over a predetermined power input / output range.

[0151] For example, Figure 11 This is an explanatory diagram of an example of loop control related to the input / output port 15a1. When the voltage on the DC bus 12 side is between V2 and V3, the microgrid 10 is in a normal state with balanced power supply and demand, and the reference function is set so that the battery 15b is not being charged or discharged (P=0).

[0152] Furthermore, when the voltage on the DC bus 12 side is between V1 and V2, the microgrid 10 is in a first quasi-normal state, where power demand is higher than normal and the voltage is lowered. The reference function is set to execute cyclic control to discharge the storage battery 15b using a relatively large droop coefficient. On the other hand, when the voltage on the DC bus 12 side is between V3 and V4, the microgrid 10 is in a second quasi-normal state, where power demand is lower than normal and the voltage is rising. The reference function is set to execute cyclic control to charge the storage battery 15b using a relatively large droop coefficient.

[0153] Furthermore, when the voltage on the DC bus 12 side is less than V1, the microgrid 10 is in a transitional state where the power demand is greater than in the first quasi-normal state, and the reference function is set so that the battery 15b discharges at a predetermined maximum power P1. On the other hand, when the voltage on the DC bus 12 side exceeds V4, the microgrid 10 is in a transitional state where the power demand is less than in the second quasi-normal state, and the reference function is set so that the battery 15b charges at a predetermined maximum power |P2|.

[0154] Furthermore, in the power network of the above-described embodiment, if any node has the structure of microgrid 10 or 10A, microgrid 10 has EDLC 13b and batteries 14b, 15b, and 16b connected to its d-port, so that the entire microgrid 10 functions as a power storage device. Furthermore, as with microgrid 10A, any node's d-port can be connected to a power company's power system to adjust the difference between inflow and outflow of power by receiving or selling power.

[0155] In addition, the present invention is not limited by the above-mentioned embodiment. The mode of appropriately combining the above-mentioned various structural elements and constituting is also included in the present invention. In addition, those skilled in the art can easily derive further effects or modifications. Thus, the broader mode of the present invention is not limited to the above-mentioned embodiment, and various changes can be implemented.

[0156] -Explanation of Symbols-

[0157] 10, 10A microgrid

[0158] 11, 21 Power Router

[0159] 11a1, 11a2, 11a3, 21a, 21b power ports

[0160] 11b1, 11b2, 11b3 Power measurement unit

[0161] 11c Control Unit

[0162] 12 DC bus

[0163] 13a, 14a, 14Aa, 15a, 16a, 17a DC / DC converters

[0164] 13a1, 13a2, 14a1, 14Aa1, 14a2, 14Aa2, 15a1, 15a2, 16a1, 16a2, 17a1, 17a2, 18a1, 18a2 Input and output ports

[0165] 13b EDLC

[0166] 14b, 15b, 16b, B3, B4, B5, B6, B7, B8, B9, B21, B22 batteries

[0167] 17b PV installation

[0168] 18a, 31 DC / AC converter

[0169] 18b load

[0170] 19, 110, 210, 310, 410 EMS

[0171] 32 Power System

[0172] 100, 100A, 200, 200A, 200B, 300, 300A, 400 Power network

[0173] 101 Linkage Line

[0174] Nodes N1, N2, N3, N4, N5, N6, N7, N8, N9, N10, N11, N12, N13, N21, and N22

[0175] P1, P2, P3, P4, P5, P6, P7, P7A, P8, P9, P10, P10A, P11, P12, P12A, P13, P14, P15, P16, P17, P17A, P18, P19, P20, P21, P22, P23, P31, P32, P33, P41, P42, P43, P51, P52, P53, P61, P62, P63, P64, P65, P66 Power path

[0176] T11, T12, T13, T14, T21, T22, T23, T24, T31, T32, T33, T34, T41, T42, T43, T44, T51, T52, T53, T54, T61, T62, T63, T64, T65, T71, T72, T73, T74, T81, T82, T83, T91, T92, T93, T101, T102, T103, T104, T111, T121, T122, T123, T131, T132, T133, T211, T212, T213, T221, T222, T223, T224 power ports.

Claims

1. A power network, characterized in that: have: a plurality of power routers having a plurality of power ports capable of inputting and outputting DC power, converting power input from any one of the plurality of power ports and outputting the power from at least one other power port; a plurality of linkage lines, connecting the plurality of power routers into a grid via the power ports; as well as a power device that consumes or supplies power and is connected to a power port of at least one of the plurality of power routers that is not connected to the linkage line; At least one of the plurality of power ports of each of the plurality of power routers is set as a row port that does not control the characteristics of input or output DC power. The plurality of power routers include: at least one first power router comprising at least one inline port connected to a power storage device capable of storing and releasing DC power; as well as at least one second power router that is not connected to a power storage device capable of storing and releasing DC power, The at least one second power router includes an in-line port connected to a first constant voltage control port among a plurality of power ports of another of the plurality of power routers, wherein the first constant voltage control port is configured to control the voltage of the input or output DC power to be constant within a given range.

2. The power network according to claim 1, wherein The row port of at least one of the multiple power routers is connected to a second constant voltage control port among the multiple power ports of at least one of the other power routers, and the second constant voltage control port is set as a port for controlling the voltage of the input or output DC power to be constant within a given range.

3. The power network according to claim 1 or 2, wherein: The power port of at least one of the plurality of power routers is a third constant voltage control port configured to control the voltage of input or output DC power to be constant within a given range. The third constant voltage control port is connected to a constant current control port of a power port configured to control the current of the DC power input or output to be constant within a given range among the plurality of power ports of the other power routers.

4. The power network according to claim 1 or 2, wherein: The device includes a control unit configured to control the operation of at least one of the plurality of power routers.

5. The power network according to claim 4, wherein: The control unit controls the operation of at least two of the plurality of power routers.

6. The power network according to claim 5, wherein: The control unit stops the operation of the power router for the power port scheduled to be connected via the interlocking line among the power ports of the at least two power routers, and maintains the operation of the power router for the power port other than the scheduled connection.

7. The power network according to claim 6, wherein: If the power port scheduled for connection is a row port, the control unit stops the operation of the power router for the row port and sets at least one of the power ports other than the scheduled connection as a row port.

8. A power network, characterized in that: have: a plurality of power routers having a plurality of power ports capable of inputting and outputting DC power, converting power input from any one of the plurality of power ports and outputting the power from at least one other power port; a plurality of linkage lines, connecting the plurality of power routers into a grid via the power ports; a power device, consuming or supplying power, connected to a power port of at least one of the plurality of power routers that is not connected to the linkage line; as well as a control unit for controlling the operation of at least one of the plurality of power routers; At least one of the plurality of power ports of each of the plurality of power routers is set as a row port that does not control the characteristics of input or output DC power. The control unit alternately switches at least one power port in the at least one power router between the row port and a control port set as a port for controlling characteristics of input or output DC power.

9. A power network, characterized in that: have: a plurality of power routers having a plurality of power ports capable of inputting and outputting DC power, converting power input from any one of the plurality of power ports and outputting the power from at least one other power port; a plurality of linkage lines, connecting the plurality of power routers into a grid via the power ports; a power device, consuming or supplying power, connected to a power port of at least one of the plurality of power routers that is not connected to the linkage line; as well as a control unit for controlling the operation of at least one of the plurality of power routers; At least one of the plurality of power ports of each of the plurality of power routers is set as a row port that does not control the characteristics of input or output DC power. The plurality of power ports of the at least one power router are respectively connected to a plurality of power storage devices capable of storing and releasing DC power. The control unit alternately switches the power ports connected to the power storage devices to the row port and the control port according to the charge states of the power storage devices.

10. A power network, characterized in that: have: a plurality of power routers having a plurality of power ports capable of inputting and outputting DC power, converting power input from any one of the plurality of power ports and outputting the power from at least one other power port; a plurality of linkage lines, connecting the plurality of power routers into a grid via the power ports; a power device, consuming or supplying power, connected to a power port of at least one of the plurality of power routers that is not connected to the linkage line; as well as a control unit for controlling the operation of at least one of the plurality of power routers; At least one of the plurality of power ports of each of the plurality of power routers is set as a row port that does not control the characteristics of input or output DC power. The control unit switches the power port connected to a power storage device whose indicator indicating a state of charge is close to an upper limit value or a lower limit value among the plurality of power storage devices from a row port to a control port.

11. A power network, characterized in that: have: a plurality of power routers having a plurality of power ports capable of inputting and outputting DC power, converting power input from any one of the plurality of power ports and outputting the power from at least one other power port; a plurality of linkage lines, connecting the plurality of power routers into a grid via the power ports; a power device, consuming or supplying power, connected to a power port of at least one of the plurality of power routers that is not connected to the linkage line; as well as a control unit for controlling the operation of at least one of the plurality of power routers; At least one of the plurality of power ports of each of the plurality of power routers is set as a row port that does not control the characteristics of input or output DC power. The control unit controls the operation of at least two of the plurality of power routers. When it is determined that a fault has occurred in at least one of the plurality of interlocking lines and the power port connected to the interlocking line having the fault is a row port, the control unit switches at least one of the other power ports of the power router having the row port to the row port.

12. The power network according to claim 11, wherein When a power port of another power router connected to the interlocking line connected to the power port switched to the row port is not a voltage constant control port, the control unit switches the power port to a voltage constant control port.

13. A method for changing a power network, characterized in that: The power network comprises: a plurality of power routers having a plurality of power ports capable of inputting and outputting DC power, converting power inputted from at least one of the plurality of power ports and outputting the power from at least one other power port; a plurality of linkage lines, connecting the plurality of power routers into a grid via the power ports; and a power device that consumes or supplies power and is connected to a power port of at least one of the plurality of power routers that is not connected to the linkage line, wherein at least one of the plurality of power ports of each of the plurality of power routers is set as a row port that does not control the characteristics of the input or output DC power. The plurality of power routers include: at least one first power router comprising at least one inline port connected to a power storage device capable of storing and releasing DC power; as well as at least one second power router that is not connected to a power storage device capable of storing and releasing DC power, The at least one second power router includes a row port connected to a first constant voltage control port among a plurality of power ports of another of the plurality of power routers, wherein the first constant voltage control port is configured to control the voltage of the input or output DC power to be constant within a given range. stopping the operation of the power router for the power ports that are scheduled to be connected via the interlocking line among the power ports of at least two of the plurality of power routers, and maintaining the operation of the power router for the power ports other than the scheduled connection; The additional power router is connected to the power port to be connected via a linkage line.

14. The method for changing the power network according to claim 13, wherein: If the power port scheduled for connection is a row port, the operation of the power router for the row port is stopped, and at least one of the power ports other than the scheduled connection is set as a row port.

15. A method for changing a power network, characterized in that: The power network comprises: a plurality of power routers having a plurality of power ports capable of inputting and outputting DC power, converting power input from at least one of the plurality of power ports and outputting the power from at least one other power port; a plurality of linkage lines, connecting the plurality of power routers into a grid via the power ports; and a power device that consumes or supplies power and is connected to a power port of at least one of the plurality of power routers that is not connected to the linkage line, wherein at least one of the plurality of power ports of each of the plurality of power routers is set as a row port that does not control the characteristics of the input or output DC power. When it is determined that a fault has occurred in at least one of the plurality of interlocking lines and the power port connected to the interlocking line having the fault is a row port, at least one of the other power ports of the power router having the row port is switched to a row port.

16. The method for changing the power network according to claim 15, wherein: If the power port of another power router connected to the interlocking line connected to the power port switched to the row port is not a constant voltage control port, the power port is switched to a constant voltage control port.

17. A method for changing a power network, characterized in that: The power network comprises: a plurality of power routers having a plurality of power ports capable of inputting and outputting DC power, converting power input from at least one of the plurality of power ports and outputting the power from at least one other power port; a plurality of linkage lines, connecting the plurality of power routers into a grid via the power ports; and a power device that consumes or supplies power and is connected to a power port of at least one of the plurality of power routers that is not connected to the linkage line, wherein at least one of the plurality of power ports of each of the plurality of power routers is set as a row port that does not control the characteristics of input or output DC power, and each of the plurality of power ports of the at least one power router is connected to a plurality of power storage devices capable of storing and releasing DC power, respectively. The power ports connected to the respective power storage devices are alternately switched between a row port and a control port according to the charge states of the respective power storage devices.

18. The method for changing the power network according to claim 17, wherein: The power port connected to a power storage device whose indicator indicating the state of charge is close to an upper limit value or a lower limit value among the plurality of power storage devices is switched from a row port to a control port.

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