Power supply network and power supply method

Abstract

To quickly construct a micro grid on the lower-level side of a power distribution breaker.SOLUTION: When power supply to power supply networks 5_1 to 5_n via a power distribution breaker 4 is stopped, in the power supply networks 5_1 to 5_n, a plurality of breakers 7_1 to 7_m is kept in an open state and a power supply control device 8 supplies power from a dispersion type power supply device 10 to distribution lines 6_1 to 6_m. When power is supplied from the dispersion type power supply device 10 and the like to the distribution lines 6_1 to 6_m connected with the primary sides of the breakers, the breakers 7_1 to 7_m sequentially changes from the open state to a closed state after a predetermined time elapses.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power supply network and a power supply method, and relates to, for example, a power supply network formed downstream of a distribution breaker. [Background technology]

[0002] In recent years, microgrids have been attracting attention as small-scale power supply networks that supply power from multiple small-scale power generation facilities to multiple consumers in a certain area. A microgrid is a power supply network that aims to achieve local production and consumption without relying on power supply from large-scale power plants by combining multiple power sources and controlling the power supply to consumers within a limited area (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-36502 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, if an accident or the like occurs in the upper system and the power supply from the upper system to the lower system is stopped, it is desirable to quickly build a microgrid in the lower system and operate the microgrid until the upper system is restored. The inventors of the present application have considered the need for a technology for more quickly establishing a microgrid on the downstream side of a distribution breaker when power supply from an upper system is stopped.

[0005] The present invention has been made in view of the above-mentioned problems, and aims to more quickly establish a microgrid on the downstream side of a distribution breaker. [Means for solving the problem]

[0006] A representative embodiment of the present invention provides a power supply network in which power is supplied from a higher-level system via a distribution circuit breaker, and the power supply network comprises a plurality of distribution lines, a plurality of switches connected between adjacent distribution lines, a distributed power supply device connected to at least one of the distribution lines, a power supply control device that controls the start and stop of the distributed power supply device, and a plurality of consumer equipment that receives power supply from the distribution lines. When power supply to the power supply network via the distribution circuit breaker is stopped, the plurality of switches are opened, and the power supply control device starts up the distributed power supply device to supply power to the distribution line connected to the distributed power supply device. When power is supplied from the distributed power supply device to the distribution line connected to the primary side of the switch, the switches are sequentially switched from an open state to a closed state after a predetermined time has elapsed. [Effects of the Invention]

[0007] According to the power supply network of the present invention, it is possible to more quickly establish a microgrid downstream of the distribution breaker. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing a configuration of a power supply system including a power supply network according to an embodiment of the present invention. [Figure 2] 1 is a flowchart illustrating an example of a flow of constructing a microgrid in a power supply network. [Figure 3A] FIG. 1 is a diagram schematically illustrating the state of a power supply network when a microgrid is constructed. [Figure 3B] FIG. 1 is a diagram schematically illustrating the state of a power supply network when a microgrid is constructed. [Figure 3C] FIG. 1 is a diagram schematically illustrating the state of a power supply network when a microgrid is constructed. [Figure 3D]FIG. 1 is a diagram schematically illustrating the state of a power supply network when a microgrid is constructed. [Figure 3E] FIG. 1 is a diagram schematically illustrating the state of a power supply network when a microgrid is constructed. [Figure 4] 10 is a flowchart showing an example of the flow of restoration of each power supply network after the fault in the upper system is resolved. [Figure 5A] FIG. 1 is a diagram schematically illustrating the state of a power supply network when the operation of a microgrid is stopped. [Figure 5B] FIG. 1 is a diagram schematically illustrating the state of a power supply network when the operation of a microgrid is stopped. DETAILED DESCRIPTION OF THE INVENTION

[0009] 1. Overview of the embodiment First, a typical embodiment of the invention disclosed in this application will be outlined. In the following description, for example, reference numerals in the drawings corresponding to components of the invention are written in parentheses.

[0010] [1] A power supply network (5_1 to 5_n) according to a representative embodiment of the present invention is a power supply network to which power is supplied from an upper system (3) via distribution circuit breakers (4_1 to 4_n), and includes a plurality of distribution lines (6_0 to 6_m), a plurality of switches (7_1 to 7_m) connected between adjacent ones of the distribution lines, distributed power supply devices (10, 11, 12) connected to at least one of the distribution lines, a power supply control device (8) that controls start and stop of the distributed power supply devices, and a power supply control device (9) that controls the power supply from the distribution lines. and a plurality of consumer equipment (14_1 to 14_p) that receives power from the power distribution network, and when the power supply to the power supply network via the distribution circuit breaker is stopped, the plurality of switches are opened, and the power supply control device starts the distributed power supply device to supply power to the distribution line connected to the distributed power supply device, and when power is supplied to the distribution line connected to the primary side of the switches (7_1 to 7_m), the switches (7_1 to 7_m) are sequentially switched from the open state to the closed state after a predetermined time has elapsed.

[0011] [2] In the power supply network described in [2] above, the other switches may be switched from an open state to a closed state based on a switching function based on a time-delay accident investigation method.

[0012] [3] In the power supply network described in [1] or [2] above, when power from the distributed power supply device is supplied to the distribution line, the power consumption of the consumer equipment connected to the distribution line may be suppressed.

[0013] [4] In the power supply network described in [3] above, the customer equipment includes loads (16_1 to 16_p) that operate by receiving power supply from the distribution line, and load control devices (15_1 to 15_p) that control the power supply to the loads, and the load control devices may suppress the power consumption of the loads by limiting the load capacity of the customer equipment.

[0014] [5] In the power supply network described in [3] above, the customer equipment includes loads (16_1 to 16_p) that operate by receiving power supply from the distribution line, and load control devices (15_1 to 15_p) that control the power supply to the loads, and the load control devices may suppress the power consumption of the loads by stopping the power supply to the loads.

[0015] [6] In the power supply network described in any one of [1] to [5] above, when power supply to the distribution line connected to the secondary side of the distribution circuit breaker is resumed, the power supply control device may adjust the power output from the distributed power supply device so that a phase difference and a voltage difference between the power output from the distributed power supply device and the power supplied to the distribution line (6_0) connected to the secondary side of the distribution circuit breaker are within predetermined reference values, and when the phase difference and the voltage difference between the power output from the distributed power supply device and the power supplied to the distribution line on the secondary side of the distribution circuit breaker are within the predetermined reference values, the switch connected to the distribution line connected to the secondary side of the distribution circuit breaker may be switched from an open state to a closed state. At this time, the function of the switch, which switches from an open state to a closed state sequentially after a predetermined time has elapsed when power is supplied to the distribution line connected to the primary side of the switch, is stopped.

[0016] [7] A method according to a representative embodiment of the present invention is a power supply method in a power supply network (5) including a plurality of distribution lines (6_0 to 6_m), a plurality of switches (7_1 to 7_m) connected between adjacent distribution lines, a distributed power supply device (10, 11, 12) connected to at least one of the distribution lines, a power supply control device (8) that controls the start and stop of the distributed power supply device, and a plurality of consumer facilities (14_1 to 14_p) that receive power supply from the distribution lines. The method is characterized by including a first step (S1) in which the plurality of switches are set to an open state when power supply from an upper system (3) to the power supply network via a distribution circuit breaker (4) is stopped; a second step (S3 to S5) in which, after the first step, the power supply control device starts up the distributed power supply device and supplies power to the distribution line connected to the distributed power supply device; a third step (S6, S12) in which the switches (7_1 to 7_m) are sequentially switched from an open state to a closed state after a predetermined time has elapsed when power from the distributed power supply device is supplied to the distribution line (6_1 to 6_m) connected to the primary side of the switches; and a fourth step (S6, S7, S10, S11) in which, when power from the distributed power supply device is supplied to the distribution line, power consumption of the consumer equipment connected to the distribution line is suppressed.

[0017] 2. Specific examples of embodiments Hereinafter, specific examples of embodiments of the present invention will be described with reference to the drawings. In the following description, components common to the embodiments will be designated by the same reference numerals, and repeated description will be omitted.

[0018] <Embodiment> FIG. 1 is a diagram showing a configuration of a power supply system 100 including a power supply network according to an embodiment of the present invention.

[0019] The power supply system 100 shown in Figure 1 is a system that, under normal circumstances, supplies power to distribution systems 5_1 to 5_n (n is an integer greater than or equal to 2) from an upper system including a distribution substation 1 via distribution circuit breakers 4_1 to 4_n (n is an integer greater than or equal to 2), and in the event of a power outage due to an accident or the like in the upper system, constructs a microgrid for each of the distribution systems 5_1 to 5_n and supplies power to multiple consumers within the distribution system.

[0020] In this specification, when describing components such as distribution circuit breakers 4_1 to 4_n, if there is no need to distinguish between the components, they may be referred to as "distribution circuit breaker 4" without adding a suffix.

[0021] As shown in FIG. 1, a power supply system 100 includes, for example, a distribution substation 1, a secondary bus 3, distribution circuit breakers 4_1 to 4_n, power supply networks 5_1 to 5_n as a power distribution system, and information processing devices 20 to 22.

[0022] A distribution substation 1 transforms power supplied to a primary bus (not shown) from a large-scale power plant such as a thermal power plant, and outputs the transformed power to a secondary bus 3 (e.g., a 6 kV bus). A plurality of distribution circuit breakers 4_1 to 4_n are connected to the secondary bus 3. When the distribution circuit breakers 4_1 to 4_n are closed, power is supplied from the secondary bus 3 connected to the primary sides of the distribution circuit breakers 4_1 to 4_n to power supply networks 5_1 to 5_n, which are power distribution systems connected to the secondary sides of the distribution circuit breakers 4_1 to 4_n, and when the distribution circuit breakers 4_1 to 4_n are opened, the power supply from the secondary bus 3 to the power supply networks 5_1 to 5_n is stopped.

[0023] Each of the distribution circuit breakers 4_1 to 4_n can be controlled individually. The opening and closing of the distribution circuit breakers 4_1 to 4_n is controlled, for example, by an information processing device (for example, an optical central unit 2) installed in the distribution substation 1. Furthermore, each of the distribution circuit breakers 4_1 to 4_n may be automatically opened when it is detected that the power supply to the primary side of the distribution circuit breaker 4_1 to 4_n has stopped due to an accident or the like in an upper system.

[0024] The distribution substation 1 includes, for example, an optical central unit 2. The optical central unit 2 is a communication device that communicates with an information processing device 20 (described later) and also communicates with switches 7_1 to 7_m (m is an integer equal to or greater than 2) installed in each of the power supply networks 5_1 to 5_n (described later). In other words, the optical central unit 2 functions as a communication device for realizing communication between the information processing device 20 and the switches 7_1 to 7_m. The optical central unit 2 can be operated by power supply from a secondary bus 3, for example.

[0025] The information processing device 20 is a device that monitors the power distribution systems (upper system and lower system) within the power supply system 100 and controls the supply and stop of power in the power distribution systems. The information processing device 20 is a program processing device such as a server, for example, a power distribution control system. Hereinafter, the information processing device 20 is also referred to as the "power distribution control system 20."

[0026] The power distribution control system 20 remotely controls the opening and closing of switches 7_1 to 7_m installed in power supply networks 5_1 to 5_n, which will be described later. For example, the power distribution control system 20 controls the opening and closing of designated switches 7_1 to 7_m by communicating with the switches 7_1 to 7_m via an optical central unit 2 provided in a power distribution substation 1. The power distribution control system 20 is also capable of wired or wireless communication with a power supply control device 8 in each of the power supply networks 5_1 to 5_n, which will be described later, and with information processing devices 21 and 22.

[0027] The information processing device 21 is a program processing device such as a server, and is, for example, a smart meter system. Hereinafter, the information processing device 21 is also referred to as a "smart meter system 21."

[0028] The smart meter system 21 is capable of wired or wireless communication with the power distribution control system 20, the information processing device 22, and load control devices 15_1 to 15_p (p is an integer of 2 or more) installed in the power supply networks 5_1 to 5_n described later.

[0029] For example, the smart meter system 21 communicates with the load control devices 15_1 to 15_p to acquire information about the states (amount of power used, contract capacity, etc.) of the loads 16_1 to 16_p under the control of the load control devices 15_1 to 15_p.

[0030] Furthermore, although details will be described later, when the smart meter system 21 receives an instruction to suppress loads (suppress power consumption) from the information processing device 22, it instructs the load control devices 15_1 to 15_p to suppress power consumption of the loads 16_1 to 16_p.

[0031] The information processing device 22 is a device that manages the supply and demand of power within the power supply networks 5_1 to 5_n. The information processing device 22 is, for example, a program processing device such as a server serving as a resource aggregator (RA) or a server that manages a VPP (Virtual Power Plant), and is a so-called RA / VPP system. Hereinafter, the information processing device 22 will also be referred to as the "RA / VPP system 22."

[0032] The RA / VPP system 22 is capable of wired or wireless communication with the power distribution control system 20, the smart meter system 21, the power supply control devices 8 in each of the power supply networks 5_1 to 5_n described later, and some of the load control devices 15_2. Based on a load reduction instruction from the power supply control device 8, the RA / VPP system 22 instructs the smart meter system 21 and some of the load control devices 15_2 to reduce power consumption in the loads, as will be described in detail later.

[0033] The power distribution control system 20, the smart meter system 21, and the RA / VPP system 22 are installed, for example, in areas different from the power supply networks 5_1 to 5_n, and even if a power outage occurs within the power supply networks 5_1 to 5_n, they can be supplied with power from another route and remain operational.

[0034] As shown in FIG. 1, on the downstream side of the distribution circuit breakers 4_1 to 4_n, power supply networks 5_1 to 5_n are formed as subordinate systems for each of the distribution circuit breakers 4_1 to 4_n.

[0035] The power supply networks 5_1 to 5_n include, for example, distribution lines 6_0 to 6_m, switches 7_1 to 7_m, a power supply control device 8, an uninterruptible power supply (UPS) 9, distributed power supply devices 10 and 13, and customer facilities 14_1 to 14_p. Each of the power supply networks 5_1 to 5_n has similar components.

[0036] For convenience of explanation, only the configuration of the power supply network 5_3 is representatively illustrated in FIG. 1, and the configuration of the power supply network 5_3 will be described in detail below.

[0037] The distribution lines 6_0 to 6_m transmit power supplied from an upper system (secondary bus 3) via a distribution breaker 4_3 to customer facilities 14_1 to 14_p and the like in the power supply network 5_3.

[0038] The switches 7_1 to 7_m are devices connected between adjacent distribution lines 6_0 and 6_m to control power transmission between the distribution lines. For example, the switches 7_1 to 7_m are automatic switches. Specifically, in the switch 7_1, the distribution line 6_0 is connected to the primary side of the switch 7_1, and the distribution line 6_1 is connected to the secondary side of the switch 7_1. In the switch 7_2, the distribution line 6_1 is connected to the primary side of the switch 7_2, and the distribution line 6_2 is connected to the secondary side of the switch 7_2. In the switch 7_3, the distribution line 6_2 is connected to the primary side of the switch 7_3, and the distribution line 6_3 is connected to the secondary side of the switch 7_3. In the switch 7_m, the distribution line 6_m-1 is connected to the primary side of the switch 7_m, and the distribution line 6_m is connected to the secondary side of the switch 7_m.

[0039] The switches 7_1 to 7_m can be opened and closed by remote control by the power distribution control system 20. For example, when the power distribution control system 20 transmits an instruction to open the switch 7_1, which is in a closed state, via the optical central device 2 of the power distribution substation 1, the switch 7_1 changes from a closed state to an open state.

[0040] When the switches 7_1 to 7_m detect that the power supply to the distribution line connected to the primary side of the switch 7_1 to 7_m has stopped, the switch 7_1 changes from the "closed state" to the "open state." For example, when the power supply to the distribution line 6_0 stops, the switch 7_1 changes from the "closed state" to the "open state." This electrically separates the distribution line 6_0 from the distribution line 6_1. Note that, since there is a risk of a short circuit or the like occurring if power is supplied from another source to a location that is being charged, the open state is maintained when it is necessary to maintain the open state.

[0041] Details will be described later, but of the multiple switches 7_1 to 7_m, except for switch 7_1 connected to distribution line 6_0 which receives power from distribution circuit breaker 4_3, the other switches 7_2 to 7_m sequentially switch from an open state to a closed state after a predetermined time has elapsed when power is supplied from distributed power supply device 10 to distribution lines 6_1 to 6_m-1 connected to the primary side of switches 7_2 to 7_m.

[0042] Specifically, the switches 7_1 to 7_m may have an opening / closing function based on a time-limited accident investigation method, for example. That is, the switches 7_2 to 7_m may be automatically switched from an open state to a closed state after a predetermined time has elapsed after power is supplied, by the opening / closing function based on the time-limited accident investigation method.

[0043] The distributed power supply devices 10 and 13 are devices that output generated or stored electric power. The distributed power supply devices 10 and 13 are linked to a power distribution system (power distribution lines 6_1 to 6_m), and the electric power generated or stored by the distributed power supply devices 10 and 13 can be supplied to the power distribution system.

[0044] For example, the distributed power supply apparatus 10 is a main emergency power supply apparatus connected to the power supply network 5_3. The distributed power supply apparatus 10 includes, for example, a generator 11. The generator 11 is a device that generates electric power based on mechanical energy. The generator 11 is, for example, a diesel generator (emergency DG). The distributed power supply apparatus 10 may include a system storage battery 12.

[0045] The distributed power supply device 13 is a power supply device linked to the power supply network 5_3, and is, for example, a large-scale photovoltaic power generator (PV: Photovoltaics).

[0046] The power supply control device 8 is a device that controls the supply and demand of power in the power supply network 5_3 by controlling the distributed power supply devices 10 installed in the power supply network 5_3. The power supply control device 8 also controls the distributed power supply devices 13 to suppress power generation, and is also capable of maintaining system stability (maintaining frequency, etc.). The power supply control device 8 is, for example, an EMS (Energy Management System) as a parent device. Hereinafter, the power supply control device 8 will also be referred to as "EMS8".

[0047] The EMS 8 controls the start and stop of the distributed power supply apparatuses that are the control targets. In this embodiment, the distributed power supply apparatus 10 is the apparatus that is the control target of the EMS 8. The EMS 8 is capable of wired or wireless communication with the power distribution control system 20, the RA / VPP system 22, and the smart meter system 21.

[0048] During normal operation when power is supplied from the upper system via the distribution circuit breaker 4_3, the EMS 8 operates using power supplied from the distribution line 6_1. On the other hand, during a power outage when the power supply from the upper system is stopped, the EMS 8 operates using power supplied from an uninterruptible power supply (UPS) 9 and starts up the distributed power supply 10 that is the control target. After the distributed power supply 10 is started up, the EMS 8 operates using power received from the distributed power supply 10 instead of the uninterruptible power supply 9.

[0049] The customer facilities 14_1 to 14_p are facilities set up within the premises of customers. Here, the customer facilities include, for example, not only ordinary homes but also buildings, factories, and the like.

[0050] 1 are examples of facilities in a typical home. The customer facilities 14_1 and 14_p include, for example, load control devices 15_1 and 15_p and loads 16_1 and 16_p, respectively.

[0051] The loads 16_1 and 16_p are, for example, electrical appliances that operate at low voltage and are installed in a customer's facility (a general household). The load 16_1 receives power supply from a distribution line 6_1 (first section), and the load 16_p receives power supply from a distribution line 6_m (mth section).

[0052] The load control devices 15_1 and 15_p are devices that control power supply to the loads 16_1 and 16_p. The load control devices 15_1 and 15_p, for example, monitor the power consumption of the loads 16_1 and 16_p to be controlled and control the power supply to the loads 16_1 and 16_p. The load control devices 15_1 and 15_p are smart meters, smart distribution boards, etc. that are capable of wired or non-wired communication with external devices (such as the smart meter system 21). Hereinafter, the load control devices 15_1 and 15_p are also referred to as "smart meters 15_1 and 15_p."

[0053] For example, the smart meters 15_1 and 15_p periodically communicate with the smart meter system 21 to transmit information on the power usage (for example, power usage every 30 minutes) of the loads 16_1 and 16_p to be controlled to the smart meter system 21. Furthermore, when receiving a load suppression instruction from the RA / VPP system 22 via the smart meter system 21, the smart meters 15_1 and 15_p suppress the power consumption of the loads 16_1 and 16_p to be controlled.

[0054] The customer facility 14_2 is an example of a facility in a building, a factory, or the like, and includes a load control device 15_2 and a load 16_2. The load 16_2 is, for example, an electric device installed in a building, a factory, or the like, and operates on high-voltage power. The load 16_2 receives power supply from a distribution line 6_2 (second section).

[0055] The load control device 15_2 is a device that controls power supply to the load 16_2. The load control device 15_2 is, for example, a power supply control device such as a BEMS (Building Energy Management System) or an FEMS (Factory Energy Management System) that monitors the power consumption of the load 16_2 to be controlled and controls the power supply to the load 16_2. Hereinafter, the load control device 15_2 will also be referred to as "xEMS 15_2."

[0056] The above-mentioned customer facilities 14_1 to 14_p may include distributed power supply devices such as PV systems connected to the power distribution system, and the power supply control device 8 may control power generation suppression to maintain system stability (maintain frequency, etc.). The above-mentioned customer facilities 14_1, 14_2, and 14_p are merely examples, and customer facilities other than the customer facilities 14_1, 14_2, and 14_p may be connected to each of the distribution lines 6_1 to 6_m of the power supply network 5_3.

[0057] As described above, each of the power supply networks 5_1 to 5_n normally receives power supply from the higher-level system (secondary bus 3) via each of the distribution circuit breakers 4_1 to 4_n. On the other hand, when a power outage occurs due to an accident or the like in the higher-level system and the distribution circuit breakers 4_1 to 4_n are opened, the power supply networks 5_1 to 5_n construct a microgrid for each of the power supply networks 5_1 to 5_n. The flow of constructing a microgrid in the power supply network 5 will be described below.

[0058] FIG. 2 is a flowchart showing an example of the flow of establishing a microgrid in the power supply network 5.

[0059] 3A to 3E are diagrams schematically showing the state of the power supply network 5 when a microgrid is constructed.

[0060] 3A, suppose that an accident occurs in the upper system (secondary bus 3), causing the power supply from the distribution substation 1 to stop, the distribution circuit breakers 4_1 to 4_n to open, and the power supply from the upper system to the power supply networks 5_1 to 5_n, which are lower systems, to stop. At this time, the power supply to the optical central unit 2 installed in the distribution substation 1 also stops, and therefore the distribution control system 20 cannot remotely control the switches 7_1 to 7_m in each of the power supply networks 5_1 to 5_n via the optical central unit 2.

[0061] When the switches 7_1 to 7_m detect that the power supply from the distribution line 6 connected to the primary side thereof has stopped, they automatically enter the "open state" as shown in Fig. 3A (step S1), thereby stopping the power supply to the customer facilities 14_1 to 14_p.

[0062] At this time, the EMS 8 in each of the power supply networks 5_1 to 5_n is in an operable state by power supply from the uninterruptible power supply 9. The EMS 8 first acquires power outage information indicating that a power outage has occurred in the power supply network 5 under its monitoring from the power distribution control system 20 (step S2).

[0063] Next, the EMS 8 starts up the distributed power supply 10 under its supervision (step S3). In response to an instruction from the EMS 8, the distributed power supply 10 starts power generation by the generator 11 and / or discharge of the grid storage battery 12 (step S4).

[0064] Because the distributed power supply 10 is connected to the distribution line 6_1 as the first section, as shown in Fig. 3B, power from the distributed power supply 10 is first supplied to the first section (distribution line 6_1) (step S5). As a result, the EMS 8 continues to operate using power supplied from the distribution line 6_1 instead of the uninterruptible power supply 9. In addition, the customer facility 14_1 connected to the distribution line 6_1 also starts up, and the smart meter 15_1 in the customer facility 14_1 becomes able to communicate with the smart meter system 21 (step S6).

[0065] Next, load reduction in the first section (distribution line 6_1) is executed (step S7). Specifically, first, the EMS 8 instructs the RA / VPP system 22 to reduce power consumption in some or all of the customer facilities 14 connected to the first section (distribution line 6_1) to which power is supplied from the distributed power supply device 10. In response to the instruction from the EMS 8, the RA / VPP system 22 instructs, for example, the smart meter 15_1 of the customer facility 14_1 to reduce power consumption.

[0066] The smart meter 15_1 suppresses the power consumption of the load 16_1 to be controlled in response to an instruction from the RA / VPP system 22. For example, the smart meter 15_1 suppresses the power consumption of the load 16_1 by limiting the load capacity of the consumer facility 14_1 (for example, by reducing the contracted capacity of the consumer facility 14_1). Alternatively, the smart meter 15_1 suppresses the power consumption of the load 16_1 by stopping the power supply to some or all of the electrical devices serving as the load 16_1 in the consumer facility 14_1. Note that it is not necessary to issue an instruction to suppress loads to consumer facilities 14 for which load suppression is not appropriate, such as hospitals.

[0067] The switch 7_2 changes from the "open state" to the "closed state" after a predetermined time has elapsed since power was supplied from the distributed power supply apparatus 10 to the first section (distribution line 6_1) due to the switching function of the time-limit accident investigation method (step S8). As a result, as shown in Fig. 3C, power is supplied from the distributed power supply apparatus 10 to the distribution line 6_2 as the second section connected to the secondary side of the switch 7_2 (step S9).

[0068] By supplying power to the second section (distribution line 6_2), the customer facility 14_2 connected to the second section (distribution line 6_2) is started up, and the xEMS 15_2 in the customer facility 14_2 becomes able to communicate with the RA / VPP system 22 (step S10). In addition, power from the distributed power supply 13 also becomes able to be supplied to the second section.

[0069] Next, the load reduction in the second section is executed (step S11). Specifically, first, the EMS 8 instructs the RA / VPP system 22 to reduce power consumption in the customer facility 14 connected to the second section (distribution line 6_2) to which power is supplied. In response to the instruction from the EMS 8, the RA / VPP system 22 instructs the xEMS 15_2 of the customer facility 14_2 connected to the second section (distribution line 6_2) to reduce power consumption. In response to the instruction from the RA / VPP system 22, the xEMS 15_2 reduces the power consumption of the load 16_2, for example, by stopping power supply to some or all of the electrical equipment serving as the load 16_2 in the customer facility 14_2.

[0070] The switch 7_3 changes from the "open state" to the "closed state" after a predetermined time has elapsed since power is supplied from the distributed power supply apparatus 10 etc. to the second section (distribution line 6_2) due to the opening and closing function of the time-limit accident investigation method (step S12). As a result, as shown in Fig. 3D, power is supplied from the distributed power supply apparatus 10 etc. to the distribution line 6_3 as the third section connected to the secondary side of the switch 7_3.

[0071] The subsequent processing is the same as the processing described above (steps S8 to S11), and in the order in which power is supplied to the primary side of the switches 7_4 to 7_m, the switches 7_4 to 7_m are sequentially closed, power is supplied to each section, and load suppression is performed for each section.

[0072] Finally, as shown in FIG. 3E, power from distributed power supply devices 10, 13, etc. is supplied to all sections (distribution lines 6_1 to 6_m) within the power supply network 5_3, and a single microgrid independent from the upper system and other power supply networks 5 is constructed in the power supply network 5_3 (step S13).

[0073] After the microgrid is constructed, the switch 7_1 is locked in the "open state" by remote control from the distribution control system 20, and the "open state" is maintained so that it does not become the "closed state" even if the upper system 6_0 is charged (step S14).

[0074] Next, a flow of restoration of each of the power supply networks 5_1 to 5_n after the fault in the upper system is resolved will be described.

[0075] FIG. 4 is a flowchart showing an example of the flow of restoration of each of the power supply networks 5_1 to 5_n after the fault in the upper system is resolved.

[0076] 5A and 5B are diagrams schematically showing the state of the power supply network 5 when the operation of the microgrid is stopped.

[0077] For example, suppose that after a microgrid is constructed in the power supply network 5_3 according to the flowchart of Figure 2 described above, power is restored to the upper system including the distribution substation 1, and power supply from the distribution substation 1 to the secondary bus 3 is resumed. As a result, the optical central unit 2 in the distribution substation 1 is restored, and the distribution control system 20 becomes able to remotely control the switches 7_1 to 7_m via the optical central unit 2 (step S21).

[0078] 5A, when the power supply to the secondary bus 3 is resumed, each of the distribution circuit breakers 4_1 to 4_n changes from the "open state" to the "closed state" (step S22). As a result, for example, power is supplied from the secondary bus 3 to the distribution line 6_0 serving as the 0th section connected to the primary side of the switch 7_1 in the power supply network 5_3 (step S23). At this time, the switch 7_1 is still maintained in the "open state" by remote control from the power distribution control system 20.

[0079] Next, the power distribution control system 20 notifies the EMS 8 in the power supply network 5_3 that power supply from the higher-level system has resumed, and in response to the notification, the EMS starts adjusting the power output from the distributed power supply apparatus 10 (the generator 11 and the system storage battery 12) (step S24). Specifically, the EMS 8 adjusts the power output from the distributed power supply apparatus 10 so that the phase difference and voltage difference between the power output from the distributed power supply apparatus 10 and the power supplied to the 0th section (distribution line 6_0) are within predetermined reference values.

[0080] The EMS 8 determines whether the phase difference and voltage difference between the power output from the distributed power supply 10 and the power supplied to the distribution line 6_0 are within predetermined reference values ​​(step S25). If the phase difference and voltage difference between the power output from the distributed power supply 10 and the power supplied to the distribution line 6_0 are not within the predetermined reference values ​​(step S25: NO), the EMS 8 continues to adjust the power output from the distributed power supply 10 (step S24).

[0081] When the phase difference and voltage difference between the power output from the distributed power supply 10 and the power supplied to the distribution line 6_0 fall within predetermined reference values ​​(step S25: YES), the EMS 8 notifies the power distribution control system 20 that the power adjustment has been completed, and as shown in FIG. 5B, the power distribution control system 20 switches the switch 7_1 from the "open state" to the "closed state" by remote control via the optical central unit 2 (step S26). As a result, power is supplied to the power supply network 5_3 from the distributed power supply devices 10 and 13 and the upper system. This situation is called loop insertion.

[0082] Next, the power distribution control system 20 notifies the EMS 8 that the loop connection has been completed, and in response to the notification, the power distribution control system 20 stops the distributed power supply device 10 (step S27). As a result, power is supplied to the power supply network 5_3 only from the upper system.

[0083] Thereafter, the load reduction in the power supply network 5_3 is stopped (step S28). Specifically, first, the EMS 8 instructs the RA / VPP system 22 to stop the load reduction. In response to the instruction from the EMS 8, the RA / VPP system 22 instructs the load control devices 15_1 to 15_p in the power supply network 5_3 to stop the load reduction, directly or via the smart meter system 21. As a result, each of the load control devices 15_1 to 15_p stops the control to reduce the power consumption of the loads 16_1 to 16_p that are the control targets. Through the above processing, the power supply network 5_3 is restored to the normal state.

[0084] As described above, in the power supply network 5 according to this embodiment, when the power supply to the power supply network 5 via the distribution circuit breaker 4 is stopped, the plurality of switches 7_1 to 7_m are opened, and the power supply control device (EMS) 8 activates the distributed power supply device 10 (the generator 11 and the system storage battery 12) to supply power to the distribution line 6 connected to the distributed power supply device 10. When power is supplied from the distributed power supply device 10 or the like to the distribution lines 6_1 to 6_m connected to the primary sides of the plurality of switches 7_1 to 7_m, the switches are sequentially switched from the open state to the closed state after a predetermined time has elapsed.

[0085] According to this, even if an accident in the upper system causes the power supply from the upper system to each power supply network 5 as a lower system to be stopped, in each power supply network 5 downstream of the distribution circuit breaker 4, the switches 7_2 to 7_m are sequentially closed in the order in which power was supplied from the distributed power supply device 10, so that a microgrid can be quickly constructed in each power supply network 5 downstream of the distribution circuit breaker 4.

[0086] Furthermore, the switches 7_2 to 7_m are switched from an open state to a closed state based on an opening / closing function based on a time-delay accident investigation method. With this, even in a situation where the switches 7_2 to 7_m cannot be remotely controlled by the power distribution control system 20 due to a power outage, the switches 7_2 to 7_m are automatically closed in the order in which power is supplied from the distributed power supply device 10 to the primary sides of the switches 7_2 to 7_m, thereby sequentially expanding the section to which power is supplied, and a microgrid can be constructed more safely and quickly.

[0087] Furthermore, in the power supply network 5, when power is supplied from the distributed power supply device 10 to the distribution line 6, the power consumption of the customer equipment 14 connected to the distribution line 6 is reduced. As a result, after power is supplied to each section (distribution lines 6_1 to 6_m), load reduction is performed for each section, so the balance of power supply and demand within the power supply network 5 is adjusted, enabling long-term operation of the microgrid.

[0088] Furthermore, in the power supply network 5, the load control device 15 may suppress the power consumption of the load 16 by limiting the load capacity of the customer facility 14. This makes it possible to easily achieve load suppression of each customer facility 14.

[0089] Furthermore, in the power supply network 5, the load control device 15 may reduce the power consumption of the load 16 by stopping the power supply to the load 16. This makes it possible to easily reduce the load of each customer facility 14.

[0090] Furthermore, in the power supply network 5, when power supply to the distribution line 6_0 connected to the secondary side of the distribution circuit breaker 4 is resumed, the power supply control device (EMS) 8 adjusts the power output from the distributed power supply device 10 so that the phase difference and voltage difference between the power output from the distributed power supply device 10 etc. and the power supplied to the distribution line 6_0 connected to the secondary side of the distribution circuit breaker 4 are within predetermined reference values. Then, when the phase difference and voltage difference between the power output from the distributed power supply device 10 etc. and the power supplied to the distribution line 6_0 on the secondary side of the distribution circuit breaker 4 are within predetermined reference values, the switch 7_1 connected to the distribution line 6_0 connected to the secondary side of the distribution circuit breaker 4 is switched from an open state to a closed state. According to this, when the upper system is restored, the power supply from the upper system to the power supply network 5 can be resumed more safely and stably without causing a temporary power outage.

[0091] <<Extension of Embodiment>> The invention made by the present inventors has been specifically described above based on an embodiment, but it goes without saying that the invention is not limited thereto and can be modified in various ways without departing from the spirit of the invention.

[0092] For example, the above-described flowcharts are examples for explaining the operation, and are not limited to these. That is, the steps shown in each diagram of the flowchart are specific examples, and the present invention is not limited to these flows. For example, the order of some processes may be changed, other processes may be inserted between each process, or some processes may be performed in parallel. [Explanation of symbols]

[0093] 1...distribution substation, 2...optical central unit, 3...secondary busbar, 4_1 to 4_n...distribution circuit breakers, 5_1 to 5_n...power supply network (distribution system), 6_0 to 6_m...distribution lines, 7_1 to 7_m...switches, 8...power supply control device, 9...uninterruptible power supply, 10...distributed power supply, 11...generator, 12...system storage battery, 13...distributed power supply, 14_1 to 14_p...customer equipment, 15_1 to 15_p...load control device, 16_1 to 16_p...load, 20...information processing device (distribution control system), 21...information processing device (smart meter system), 22...information processing device (RA / VPP system).

Claims

1. A power supply network in which power is supplied from a higher-level system via a distribution circuit breaker, Multiple distribution lines; a plurality of switches connected between adjacent ones of the distribution lines; a distributed power supply device connected to at least one of the power distribution lines; a power supply control device that controls activation and shutdown of the distributed power supply device; a plurality of customer facilities that receive a supply of power from the distribution line; when power supply to the power supply network via the distribution circuit breaker is stopped, the plurality of switches are opened, and the power supply control device starts up the distributed power supply devices to supply power to the distribution lines connected to the distributed power supply devices; When power is supplied from the distributed power supply device to the power distribution line connected to the primary side of the switch, the switch sequentially switches from an open state to a closed state after a predetermined time has elapsed, When power from the distributed power supply device is supplied to the power distribution line, power consumption of the customer equipment connected to the power distribution line is reduced. Electricity supply network.

2. 2. The power supply network according to claim 1, The plurality of switches are switched from an open state to a closed state based on a switching function based on a time-delay accident investigation method. Electricity supply network.

3. 2. The power supply network according to claim 1, The customer facility includes a load that operates by receiving power supply from the distribution line, and a load control device that controls power supply to the load, The load control device limits the load capacity of the customer facility to suppress the power consumption of the load. Electricity supply network.

4. 2. The power supply network according to claim 1, The customer facility includes a load that operates by receiving power supply from the distribution line, and a load control device that controls power supply to the load, The load control device reduces power consumption of the load by stopping power supply to the load. Electricity supply network.

5. 2. The power supply network according to claim 1, when power supply to the distribution line connected to the secondary side of the distribution circuit breaker is resumed, the power supply control device adjusts the power output from the distributed power supply device so that a phase difference and a voltage difference between the power output from the distributed power supply device and the power supplied to the distribution line connected to the secondary side of the distribution circuit breaker are within predetermined reference values; When the phase difference and voltage difference between the power output from the distributed power supply device and the power supplied to the distribution line on the secondary side of the distribution circuit breaker fall within the predetermined reference values, the switch connected to the distribution line connected to the secondary side of the distribution circuit breaker switches from an open state to a closed state. Electricity supply network.

6. A power supply method in a power supply network including a plurality of distribution lines, a plurality of switches connected between adjacent ones of the distribution lines, a distributed power supply device connected to at least one of the distribution lines, a power supply control device that controls start-up and shutdown of the distributed power supply device, and a plurality of consumer facilities that receive power supply from the distribution lines, the method comprising: a first step of opening the plurality of switches when power supply from an upper system to the power supply network via a distribution circuit breaker is stopped; a second step of, after the first step, starting up the distributed power supply device by the power supply control device and supplying power to the power distribution line connected to the distributed power supply device; a third step in which, when power is supplied from the distributed power supply device to the power distribution line connected to the primary side of one of the plurality of switches, the switch is sequentially switched from an open state to a closed state after a predetermined time has elapsed; a fourth step of suppressing power consumption of the customer equipment connected to the distribution line when power from the distributed power supply device is supplied to the distribution line; A power supply method including:

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