DC power distribution system, and DC switchboard

Abstract

To provide a DC power distribution system capable of flexibly constructing power distribution routes according to the equipment configuration or situation, or a DC switchboard.SOLUTION: A DC wiring LNd goes around via at least two DC switchboards 1 out of multiple DC switchboards 1 to form a DC loop wiring. The first DC switchboard 1B, which is one of the multiple DC switchboards 1, has a dual-direction DC / DC converter 11A, and is configured. The DC storage device 4, which stores DC power, is configured to be connected via a bidirectional DC / DC converter 11A. The power distribution system control device 6 controls the bi-directional DC / DC converter 11A to regulate the power flow on the DC wiring LNd.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a DC power distribution system and a DC distribution board.

Background Art

[0002] Patent Document 1 (Japanese Patent Application Laid-Open No. 2015-163032) discloses a power supply system that supplies power from a DC power supply device to a load device via a power supply path. A switch unit is inserted into the power supply path. Also, as connection forms of the power supply path, a tree-shaped power supply path, a bus-type power supply path, and a loop-type power supply path are shown. In the tree-shaped power supply path, a load device is connected to the end of a path branched in a tree shape. In the bus-type power supply path, a distribution board is connected to the end branched from a branch point on the bus. In the loop-type power supply path, a plurality of load devices are connected to a loop wiring connected to one distribution board.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, as one of the measures against global warming, the spread of renewable energy has been progressing. Among them, in particular, solar power generation, which is easy to install, has attracted attention. In solar power generation, as part of the improvement of energy utilization efficiency, a DC power distribution method that distributes DC power generated by solar power generation to a load without going through the conversion to AC is being studied.

[0005] In addition, when a power storage device is provided in addition to solar power generation, the surplus power generated by solar power generation can be stored. This enables operations such as promoting self-use, reducing energy costs through charge and discharge according to fluctuations in the unit price of retail electricity, and backing up important loads during disasters. Also in the power storage device, similar to solar power generation, an improvement in utilization efficiency by DC power distribution is expected.

[0006] Here, for example, when it is assumed that a DC power distribution path is widely laid across the entire floor of factory facilities or the like, it is conceivable to use a power distribution path such as a tree type, a bus type, or a loop type as shown in Patent Document 1. Also, it is conceivable to insert a switch into the power distribution path. When such a configuration is used, it is possible to limit the power distribution range to stop power distribution to a specific range by opening and closing the switch. However, for example, when the configuration of the facility is changed, or when the operating status of the facility or the power generation status of solar power generation changes, it has been difficult to flexibly construct a power distribution path according to the configuration or status of the facility.

[0007] The present invention has been made in view of such circumstances, and one of its objects is to provide a DC power distribution system or a DC switchboard that can flexibly construct a power distribution path according to the configuration or status of a facility.

[0008] The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

Means for Solving the Problems

[0009] A DC power distribution system according to an embodiment includes a plurality of DC distribution boards that distribute input DC power, a DC wiring that transmits DC power between the plurality of DC distribution boards, and a power distribution system control device that centrally controls the plurality of DC distribution boards. The DC wiring forms a DC loop wiring by making a round trip through at least two or more of the plurality of DC distribution boards. A first DC distribution board, which is one of the plurality of DC distribution boards, has a bidirectional DC / DC converter, and a DC power storage device that stores DC power is configured to be connectable via the bidirectional DC / DC converter. The power distribution system control device adjusts the power flow on the DC wiring by controlling the bidirectional DC / DC converter.

Advantages of the Invention

[0010] According to the above embodiment, a power distribution path can be flexibly constructed according to the configuration or situation of the equipment.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

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Figure 5A

Figure 5B

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Figure 8A

Figure 8B

Figure 8C

Figure 8D

Figure 8E

Figure 9

Figure 10A

Figure 10B

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments are examples for explaining the present invention, and for the sake of clarity of explanation, appropriate omissions and simplifications have been made. The present invention can also be implemented in various other forms. Unless otherwise limited, each component may be singular or plural. In the drawings, the positions, sizes, shapes, ranges, etc. of the components shown may not represent the actual positions, sizes, shapes, ranges, etc. for the purpose of facilitating the understanding of the invention. For this reason, the present invention is not necessarily limited to the positions, sizes, shapes, ranges, etc. disclosed in the drawings.

[0013] As examples of various types of information, it may be described using expressions such as "table", "list", "queue", etc., but the various types of information may be represented by data structures other than these. For example, various types of information such as "XX table", "XX list", "XX queue" may be referred to as "XX information". When explaining identification information, expressions such as "identification information", "identifier", "name", "ID", "number", etc. are used, and these can be replaced with each other.

[0014] Also, when there are multiple components having the same or similar functions, they may be described by attaching different subscripts to the same reference numeral. For example, if the reference numeral of a certain component is "1", the multiple components may be distinguished as "1A", "1B", etc. When there is no need to distinguish these multiple components, the subscripts may be omitted in the description.

[0015] In the embodiments, the processing performed by executing a program may be described. As an example, a computer executes a program by a processor (e.g., CPU, GPU), and performs the processing defined by the program while using storage resources (e.g., memory) and interface devices (e.g., communication ports), etc. Therefore, the subject of the processing performed by executing the program may be the processor. Also, the subject of the processing performed by executing the program may be a controller, device, system, computer, or node having a processor.

[0016] Furthermore, the subject of the processing performed by executing the program may be an arithmetic unit and may include a dedicated circuit for performing a specific processing. Here, the dedicated circuit is, for example, an FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), a CPLD (Complex Programmable Logic Device), etc.

[0017] The program may be installed in a computer from a program source. The program source may be, for example, a program distribution server or a computer-readable storage medium. When the program source is a program distribution server, the program distribution server includes a processor and a storage resource for storing the program to be distributed, and the processor of the program distribution server may distribute the program to be distributed to other computers. Also, in the embodiments, two or more programs may be realized as one program, or one program may be realized as two or more programs.

[0018] (First Embodiment) <Configuration of DC Power Distribution System> FIG. 1 is a schematic diagram showing a configuration example of a DC power distribution system according to the first embodiment. The DC power distribution system shown in FIG. 1 is applied to various facilities typified by a production factory or the like. The DC power distribution system includes a plurality of, in this example, three DC distribution boards 1A, 1B, and 1C, a plurality of, in this example, three DC switches 5, a power distribution system control device 6, and an energy management device 7. Each DC distribution board 1 distributes the input DC power. That is, the plurality of DC distribution boards 1 are connected to each other via the DC wiring LNd, and transmit DC power via the DC wiring LNd.

[0019] Here, the DC wiring LNd forms a DC loop wiring by circulating through at least two or more of the plurality of DC distribution boards 1. In this example, the DC loop wiring is formed by passing through the three DC distribution boards 1A, 1B, and 1C, but as a minimum unit, it can also be formed by passing through two DC distribution boards 1. Each DC distribution board 1 mainly includes a DC branch part 10, a DC / DC converter 11, a current sensor 12, a DC circuit breaker 13, and a distribution board controller 14.

[0020] The DC branch unit 10 connects a plurality of DC wiring lines LNd drawn to the outside, and is a part of a power circuit that aggregates or branches the plurality of DC wiring lines LNd. For example, it is composed of a conductive material such as a copper bar or a terminal block. The DC / DC converter 11 is connected to the DC branch unit 10 via a power supply wiring line LNp. The DC / DC converter 11 converts power between the primary DC terminal and the secondary DC terminal. In the specification, the terminal on the side connected to the DC branch unit 10 is referred to as the secondary side.

[0021] The current sensor 12 measures the current in each wiring connected to the DC branch unit 10. In this example, the current sensor 12 measures the current flowing in the power supply wiring line LNp connected to the DC / DC converter 11, the load power line LNl connected to the external DC load 2 via the DC breaker 13, and the plurality of DC wiring lines LNd connected to the outside, respectively.

[0022] The DC breaker 13 is a breaker for connecting the DC load 2 provided outside the DC switchboard 1 to the DC branch unit 10, and is inserted into the load power line LNl that connects the DC load 2 and the DC branch unit 10. Specifically, when an abnormal current associated with a ground fault, short circuit, etc. occurs in the load power line LNl, the DC breaker 13 detects the abnormal current and cuts off the path of the load power line LNl. Thereby, the DC breaker 13 protects other DC systems connected to the DC branch unit 10.

[0023] Also, in this example, a DC distributed power source 3 is connected to the primary side of the DC / DC converter 11A included in the DC switchboard (second DC switchboard) 1A. The DC distributed power source 3 can be composed of, for example, a solar power generation panel or a collector box connected thereto. In this case, the DC / DC converter 11A only needs to have a one-way power conversion function from the primary side to the secondary side. When using a solar power generation panel, it is desirable to be equipped with a function such as a maximum power point tracking control that searches for the maximum power point by operating the terminal voltage with respect to the solar irradiance. This function can be installed in, for example, any one of the DC / DC converter 11, the switchboard controller 14, or the energy management device 7.

[0024] On one hand, a DC power storage device 4 is connected to the primary side of a DC / DC converter 11B included in a DC distribution board (first DC distribution board) 1B. As the DC power storage device 4, for example, a lithium-ion battery, a lead-acid battery, an electric double-layer capacitor, a lithium-ion capacitor, an electrolytic capacitor, etc. can be applied. The DC / DC converter 11B when connecting the DC power storage device 4 is preferably a bidirectional DC / DC converter. The bidirectional DC / DC converter has a bidirectional power conversion function in the direction from the primary side to the secondary side and in the direction from the secondary side to the primary side.

[0025] As in this example, by connecting a DC distributed power source 3 to the DC distribution board 1A and a DC power storage device 4 to the DC distribution board 1B respectively, and configuring the two DC distribution boards 1 at both ends to be able to distribute power through the DC wiring LNd, for example, system operation such as enhancing energy self-sufficiency by renewable energy becomes possible. That is, for example, when the DC generated power generated in the DC distribution board 1A becomes surplus compared to the consumption of the DC load 2A, this surplus power can be charged to the DC power storage device 4 of the DC distribution board 1B. And the power charged to the DC power storage device 4 can be used, for example, when the DC generated power is insufficient or in the event of a disaster.

[0026] When using the DC power storage device 4, in order to prevent overcharging that may occur due to a finite power storage energy capacity, for example, it is desirable to be equipped with a function such as managing the state of charge (SOC). This function can be installed, for example, in a distribution board controller 14 or an energy management device 7, etc.

[0027] The DC switch 5 is inserted into the DC wiring LNd and is configured to be able to open and close between two terminals. In this example, one DC switch 5 is inserted into each of the three DC wirings LNd that connect a plurality of DC switchboards 1A, 1B, and 1C to each other. The DC switch 5 is opened and closed according to various purposes. As an example, the DC switch 5 can be opened and closed for the purpose of reducing the wiring loss according to the status of the generated power on the system and the power consumption of the DC load 2. Or, the DC switch 5 can be opened and closed for the purpose of locally insulating a part of the DC switchboard 1 for regular maintenance.

[0028] The switchboard controller 14 can be realized, for example, by a wiring board equipped with a microcontroller including a processor, a memory, and an external communication interface. The switchboard controller 14 controls the entire DC switchboard 1. As one of them, the switchboard controller 14 acquires information from the current sensor 12 and the DC / DC converter 11 provided inside the DC switchboard 1, and further transmits and receives information to and from the power distribution system control device 6 provided outside or the switchboard controller 14 included in another DC switchboard 1. Then, the switchboard controller 14 controls the DC / DC converter 11 by giving a command value to the DC / DC converter 11 based on the obtained information.

[0029] In addition, the switchboard controller 14 may be provided with a DC switch operation circuit for driving the DC switch 5 to open and close. The DC switch operation circuit includes, for example, a driver circuit that outputs a drive signal for opening and closing the DC switch 5. In this case, the switchboard controller 14 drives the DC switch 5 installed in the vicinity to open and close in response to an opening and closing command from the outside, for example, the power distribution system control device 6.

[0030] Each of the power distribution system control device 6 and the energy management device 7 can be realized by, for example, a computer system including a processor, a memory, and an external communication interface. The power distribution system control device 6 mainly comprehensively controls the operation of the entire DC power distribution system. As one of them, the power distribution system control device 6 adjusts the power flow on the DC wiring LNd, that is, the DC loop wiring, by controlling the DC / DC converter 11. On the other hand, the energy management device 7 mainly manages the power generated or consumed in the entire DC power distribution system.

[0031] In this example, the power distribution system control device 6 and the energy management device 7 are provided separately. However, since both are devices that communicate and control the DC switchboard 1, a single management device integrating both functions may be provided. Alternatively, a system configuration may be adopted in which some functions, such as the functions of the energy management device 7, are implemented in a cloud server, and the remaining functions are implemented in on-site facilities such as a production factory, and both are operated in cooperation.

[0032] FIG. 2 is a schematic diagram showing a configuration example of a DC power distribution system in which the configuration shown in FIG. 1 is expanded. The DC power distribution system shown in FIG. 2 includes, in addition to the three DC switchboards 1A, 1B, and 1C shown in FIG. 1, one more DC switchboard 1D. For example, the DC switchboard 1A inputs or outputs power Pa to / from the outside based on the difference between the generated power by the DC distributed power source 3 as shown in FIG. 1 and the consumed power by the DC load 2A. Similarly, the DC switchboards 1B, 1C, and 1D respectively input or output powers Pb, Pc, and Pd to / from the outside based on the power by the DC distributed power source 3 or the DC energy storage device 4 and the power by the DC load 2.

[0033] When such a configuration is used, similar to the case of Fig. 1, a DC loop wiring LP1 is formed by three DC wirings LNd between three DC switchboards 1A, 1B, and 1C. In addition to this, another DC loop wiring LP2 is formed by three DC wirings LNd between another three DC switchboards 1B, 1C, and 1D. In the specification, a power distribution path in which a plurality of DC loop wirings are arranged in a lattice or mesh shape is called a mesh-shaped power distribution path.

[0034] In this example, two DC loop wirings LP1 and LP2 are formed. However, for example, if one more DC switchboard 1 is added, three or four DC loop wirings can be formed. In a mesh-shaped power distribution path, at least one of a plurality of DC switchboards 1, in the example shown in Fig. 2, each of the two DC switchboards 1B and 1C is commonly connected to a plurality of DC loop wirings LP1 and LP2.

[0035] As described above, by forming a DC loop wiring via a plurality of DC switchboards 1, a power distribution path according to the equipment situation can be flexibly constructed. As an example, in Fig. 1, even when the generated power from the DC distributed power source 3 connected to the DC switchboard 1A is insufficient, power can be supplied from the DC storage device 4 connected to the DC switchboard 1B to the DC loop wiring, and thus to the DC loads 2A, 2B, and 2C connected to the DC loop wiring. Or, for example, even when a failure occurs in the clockwise power distribution path for a predetermined DC load 2, an alternative counterclockwise path can be ensured.

[0036] Also, for example, as shown in Fig. 1, a wiring topology in which the power flow in the DC wiring LNd between adjacent DC switchboards 1, in this example, the power flow in the three DC wirings LNd can be individually adjusted by the input power or output power by the three DC switchboards 1A, 1B, and 1C can be constructed. Therefore, according to the equipment configuration or situation, the power flow of each DC wiring LNd can be finely adjusted, and as a result, a power distribution path according to the equipment configuration or situation can be flexibly constructed.

[0037] Furthermore, by using a mesh-shaped power distribution path as shown in FIG. 2, a power distribution path can be flexibly constructed according to the configuration or situation of the facility. That is, for example, if a mesh-shaped power distribution path is formed in advance in a facility such as a production factory, even when the configuration or arrangement of the devices in the facility changes, or when the operating status of the facility or the power generation status of solar power generation changes, a suitable power distribution path corresponding to the changed content can be flexibly constructed. Specifically, for example, in order to reduce power transmission loss, the power distribution path can be determined using the DC switch 5, and the power flow in the power distribution path, specifically in each DC wiring LNd, can be adjusted using the DC distribution board 1.

[0038] Note that, for example, in a power distribution path using a tree-like, bus system, or loop system as shown in Patent Document 1, when changing the configuration of the facility, it may be necessary to re-lay the power source. Also, in such a power distribution path, it is difficult to finely adjust the power flow. Furthermore, for example, in a tree-like power distribution path, it is necessary to arrange batteries in the main trunk system and start the branch circuits in order. On the other hand, in a mesh-shaped power distribution path, first, the sections that can be powered by arbitrarily arranged batteries are activated and stabilized, and then a step-by-step activation such as gradually expanding the sections can be performed. Therefore, especially the backup activation in an emergency becomes flexible.

[0039] <Details of the DC Distribution Board> FIG. 3 is a perspective view showing an example of the internal configuration of the DC distribution board 1 in FIG. 1. The DC distribution board 1 shown in FIG. 3 is composed of a single housing 17 that houses a plurality of components. The plurality of components include DC power storage devices 4A, 4B, DC branch parts 10P, 10N, a DC / DC converter 11, current sensors 12G, 12L, 12B, DC circuit breakers 13A, 13B, 13C, a distribution board controller 14, and an overcurrent protection element 15. The DC / DC converter 11 is a bidirectional DC / DC converter in this example.

[0040] A plurality of DC wiring lines LNd drawn to the outside are connected to the positive and negative DC branch portions 10P and 10N. As described in FIG. 1, the plurality of DC wiring lines LNd transmit power to each other between the other DC switchboards 1. In order to form a DC loop wiring, at least two or more DC wiring lines LNd are connected to the DC branch portion 10. In this example, three or three pairs of DC wiring lines LNd1, LNd2, and LNd3 are connected. And any one of the plurality of DC wiring lines LNd is connected to any other one of the plurality of DC wiring lines LNd via an external wiring path.

[0041] The first current sensor 12G measures the currents of the three DC wiring lines LNd1, LNd2, and LNd3 respectively. The second current sensor 12L measures the current of the load power line LNl connecting the DC branch portion 10 and the DC breaker 13. The third current sensor 12B measures the current of the power supply line LNp connecting the DC branch portion 10 and the DC / DC converter 11.

[0042] The overcurrent protection element 15 is composed of, for example, a fuse or a thermistor, and is inserted into a part of the wiring inside the panel, in this example, the power supply line LNp. By providing the overcurrent protection element 15, safety measures such as preventing the spread of influence can be realized when an overcurrent occurs due to a short circuit in the circuits before and after it. In this example, the switchboard controller 14 is provided with a DC switch operation circuit as described in FIG. 1. Thereby, the switchboard controller 14 drives the DC switch 5 to open and close in response to an opening and closing command from, for example, the power distribution system control device 6.

[0043] Thus, in the example shown in FIG. 3, the DC storage device 4 is housed inside the housing 17 constituting the DC switchboard 1. And two DC storage devices 4A and 4B are respectively connected to two storage device terminals provided on the DC / DC converter 11. By configuring the DC / DC converter 11 to be able to connect a plurality of DC storage devices 4 in this way, even if a failure occurs in the DC storage device 4A, the system can continue to operate with the DC storage device 4B.

[0044] In addition, when the DC power storage device 4 is composed of power storage modules in which a plurality of single cells are connected in series or in parallel, as shown in FIG. 3, it is desirable to provide a power storage controller 4C that manages the voltage of the internal single cells. The power storage controller 4C manages the voltage of such single cells, for example, through communication with a controller within the DC power storage device 4 and the DC / DC converter 11.

[0045] Also, as shown in FIG. 3, when the DC distribution board 1 is composed of a substantially rectangular parallelepiped housing 17, it is desirable that the housing 17 be provided with a first wiring hole 18a above and a second wiring hole 18b below. The first wiring hole 18a is a hole for drawing out a DC wiring LDd connected to the DC branch portion 10 to the outside. The second wiring hole 18b is a hole for drawing out a load power line LNl connected to the DC branch portion 10 to the outside. The load power line LNl is connected to an external DC load 2 via a primary DC circuit breaker 13A and secondary DC circuit breakers 13B and 13C.

[0046] By using such a DC distribution board 1, a mesh-shaped power distribution path as shown in FIG. 2 can be easily constructed. Due to the internal layout configuration of such a DC distribution board 1, although details will be described in FIG. 9, from the perspective of the equipment layout, it becomes easier to incorporate the DC distribution board 1 into the equipment. Also, since power is transmitted in the order of the primary DC circuit breaker 13A and the secondary DC circuit breakers 13B and 13C, it is excellent in preventing misoperations. In the specification, the directions horizontal to the ground are defined as the X-axis direction and the Y-axis direction, and the direction perpendicular to the ground is defined as the Z-axis direction. Above and below represent the relative positional relationship in the Z-axis direction.

[0047] Furthermore, as shown in FIG. 3, the DC power storage device 4 is provided below the DC / DC converter 11, and the DC branch portion 10 is provided above the DC / DC converter 11. Thereby, for example, when an insulated DC / DC converter 11 is used, the DC power storage device 4 and the DC branch portion 10 can be clearly insulated, and the prevention of creepage between the DC / DC converter 11 can be strengthened.

[0048] In addition, the accommodation space of the DC power storage device 4 is provided below the housing 17. This facilitates replacement work and the like when replacing the DC power storage device 4, which generally has a large weight and a short lifespan. Furthermore, since the DC power storage device 4 is generally a heat-generating component, cooling can be effectively promoted by taking in outside air at a relatively low position.

[0049] <Details of the power distribution system control device> FIG. 4 is a block diagram showing a configuration example of the power distribution system control device 6 in FIG. 1. The configuration shown in FIG. 4 can be realized by, for example, a computer system including a processor and a memory, and can be mainly realized by program processing using the processor. The power distribution system control device 6 includes a wiring information storage unit 61, an operation policy information storage unit 62, an opening / closing state acquisition unit 63, a power flow state acquisition unit 64, a noise detection unit 65, a power flow simulation unit 66, an opening / closing operation unit 67, and a voltage adjustment unit 68.

[0050] The wiring information storage unit 61 preliminarily holds information on the connection relationship via the DC wiring LNd between a plurality of DC switchboards 1. Specifically, the wiring information storage unit 61 holds, for example, information on which DC switchboard 1 each end of the individual DC wiring LNd is connected to, and further which position of the DC branch unit 10 it is connected to, as well as information on the type, wiring resistance, and heat resistance index of the DC wiring LNd. The operation policy information storage unit 62 holds information on the operation policy of a predetermined system, such as items and target values of evaluation indicators. The wiring information storage unit 61 and the operation policy information storage unit 62 are realized by a memory.

[0051] The opening / closing state acquisition unit 63 acquires the opening / closing state of the DC switch 5, for example, through communication with the DC switch 5 or communication with the switchboard controller 14 responsible for the opening / closing drive of the DC switch 5. The power flow state acquisition unit 64 acquires the power flow information of the DC wiring LNd. Specifically, the power flow state acquisition unit 64 acquires the detection information by each current sensor 12, the current and voltage information detected within the DC / DC converter 11, etc. through communication with each switchboard controller 14. As a result, in the entire DC power distribution system, the state of the current flowing through each DC wiring LNd, the state of the voltage applied to each DC wiring LNd, etc. are determined.

[0052] The noise detection unit 65, details of which will be described later, detects that a noise current is superimposed on the DC loop wiring based on the information acquired by the opening / closing state acquisition unit 63 and the power flow state acquisition unit 64. Generally, when electromagnetic external noise occurs in a circular conductor, it is known that a reflux current is induced by electromagnetic induction. The reflux current generated by noise becomes an error when determining the power flow of the entire system.

[0053] Therefore, by identifying the noise current, it becomes possible to perform error cancellation processing. Specifically, the power distribution system control device 6 may correct the acquired data of the power flow state acquisition unit 64, for example, the current data, so as to cancel the current change due to noise. Alternatively, the power distribution system control device 6 may suppress the generation of the noise current itself by changing some of the DC switches 5 on the DC loop wiring where noise occurs to the open state. In a mesh-shaped power distribution path, even if a part of the loop is opened in this way, power distribution to the DC load 2 can be maintained.

[0054] The power flow simulation unit 66 constructs an electric circuit model and parameters representing voltage values, current values, or power values on the electric circuit model based on the information held by the wiring information storage unit 61 and the information acquired by the opening / closing state acquisition unit 63 and the power flow state acquisition unit 64. Then, the power flow simulation unit 66 performs a predictive calculation of the power flow change when the value of a predetermined parameter is changed. Alternatively, the power flow simulation unit 66 performs a predictive calculation of the power flow change when the opening / closing state of the DC switch 5 is changed.

[0055] As an example, the power flow simulation unit 66 performs a predictive calculation of the power flow change when changing the DC voltage of an arbitrary DC distribution board 1 from the current operating state. Alternatively, the power flow simulation unit 66 predicts the power flow change and the terminal voltage change of a plurality of DC distribution boards 1 when changing the DC power of an arbitrary bidirectional DC / DC converter from the current operating state. Then, while performing such a parameter scan, the power flow simulation unit 66 specifies parameter conditions such that the evaluation index defined by the operation policy information storage unit 62 approaches the target value. For example, the power flow simulation unit 66 specifies how much the DC voltage from which DC distribution board 1 should be adjusted.

[0056] Based on the predictive calculation result of the power flow simulation unit 66, the opening / closing operation unit 67 outputs an opening / closing command to a predetermined DC switch 5 or the distribution board controller 14 responsible for driving its opening / closing. That is, the opening / closing operation unit 67 determines based on the predictive calculation result of the power flow simulation unit 66 whether the evaluation index approaches the target value by changing the opening / closing state of a predetermined DC switch 5, and changes the opening / closing state so as to approach the target value.

[0057] Also, based on the detection result of the noise detection unit 65, the opening / closing operation unit 67 outputs an opening / closing command to a predetermined DC switch 5 or the distribution board controller 14 to open the loop. Note that when such an opening / closing operation unit 67 is provided, the opening / closing state acquisition unit 63 may be configured to acquire the operation result of the opening / closing operation unit 67.

[0058] Based on the prediction calculation result of the power flow simulation unit 66, the voltage adjustment unit 68 outputs a voltage adjustment command value ΔV representing the voltage adjustment amount to any one of the plurality of DC switchboards 1. * That is, the voltage adjustment unit 68 notifies the DC switchboard 1 specified by the power flow simulation unit 66 of the specified voltage adjustment amount. Also, although details will be described later, when an opening / closing command for an arbitrary DC switch 5 is output by the opening / closing operation unit 67, the voltage adjustment unit 68 also notifies the DC switchboard 1 specified by the power flow simulation unit 66 of the specified voltage adjustment amount in order to reduce the damage to the DC switch 5.

[0059] In this way, by providing the power flow simulation unit 66, in other words, the distribution system control device 6 equipped with a circuit simulator, it becomes possible to sequentially optimize the operation of the DC distribution system, specifically the power flow state and the like, based on the system operation policy. Also, by providing the noise detection unit 65, it is possible to detect the noise current that may be a side effect due to the DC loop wiring, and to take measures to reduce the influence of the noise current.

[0060] <Details of the bidirectional DC / DC converter> FIG. 5A is a circuit diagram showing a configuration example of a bidirectional DC / DC converter, which is a form of the DC / DC converter 11 in FIG. 1. FIG. 5B is a block diagram showing a configuration example of the DC / DC converter controller 110 in FIG. 5A. The bidirectional DC / DC converter shown in FIG. 5A includes a primary side terminal PNp1, PNn1, a secondary side terminal PNp2, PNn2, a main circuit that converts power between both terminals, and a DC / DC converter controller 110 that controls the main circuit.

[0061] The main circuit includes an isolation transformer 112 that isolates the primary side and the secondary side, a semiconductor switch group 111 with a bridge configuration that drives the primary side of the isolation transformer 112, a semiconductor switch group 113 with a bridge configuration that drives the secondary side of the isolation transformer 112, and DC capacitors 114 and 115 connected to the secondary side. Also, in order to facilitate energy transfer by switching, an inductance element or a capacitance element (not shown in the figure) may be added to the primary side or the secondary side. Such a main circuit is called a dual active bridge (DAB) and can conduct power bidirectionally.

[0062] As an example, in a DAB, by controlling the phase difference between the switching phase of the semiconductor switch group 111 and the switching phase of the semiconductor switch group 113, the magnitude of the power and the direction of power transmission can be controlled. Note that various configurations can be applied to the main circuit of the DC / DC converter 11, not limited to such a DAB. That is, an appropriate main circuit may be selected by appropriately combining unidirectional / bidirectional types and isolation / non-isolation types according to the system configuration and application.

[0063] Also, in this example, a method is shown in which a capacitor group composed of a plurality of DC capacitors 114 and 115 connected in series is connected between the secondary side terminals PNp2 and PNn2 of the DC / DC converter 11, and the neutral point of the capacitor group is grounded. By using such a method, the voltage difference between the ground voltage GND and the secondary side voltage can be reduced, so the selection of voltage withstand components and the difficulty of testing can be lowered, and the cost of the system can be reduced.

[0064] The DC / DC converter controller 110 inputs detection information such as the primary-side voltage V1, primary-side current I1, secondary-side voltages V2H, V2L, and secondary-side currents I2H, I2L detected using sensors. Then, based on the operation command value obtained from the external communication terminal Com_M, the internal information of the DC power storage device 4 collected from the power storage controller communication terminal Com_B, and the input detection information, the DC / DC converter controller 110 controls the conversion operation of the main circuit. In this example, the DC / DC converter controller 110 controls the switching operation of the semiconductor switch group 111 using the control signals SW11 - SW14, and controls the switching operation of the semiconductor switch group 113 using the control signals SW21 - SW24.

[0065] Note that the external communication terminal Com_M is connected to the switchboard controller 14 in FIGS. 1 and 2. The power storage controller communication terminal Com_B is connected to the power storage controller 4C in FIG. 3. Also, the DC / DC converter controller 110 can be realized, for example, by program processing using a processor in a microcontroller or by an FPGA or the like.

[0066] More specifically, the DC / DC converter controller 110 includes, for example, as shown in FIG. 5B, a charge / discharge power control unit 116, a voltage adjustment control unit 117, a power storage side charge / discharge control unit 118, and a maximum power point tracking control unit 119. The charge / discharge power control unit 116 generates a first command value based on, for example, the charge / discharge power command value P * input from the energy management device 7 or the like to the switchboard controller 14 and the external communication terminal Com_M, and the detection information (V2H, V2L, I2H, I2L) by the sensors. The charge / discharge power command value P * can be appropriately changed, taking into account, for example, reducing the energy cost.

[0067] The voltage adjustment control unit 117 receives the voltage adjustment command value ΔV *Based on the detection information (V2H, V2L) from the sensor, a second command value is generated. The power storage side charge / discharge control unit 118 controls the voltage or current of the DC power storage device 4 based on the first command value from the charge / discharge power control unit 116 and the second command value from the voltage adjustment control unit 117.

[0068] A storage battery, which is a representative example of the DC power storage device 4, charges and discharges electric power through a chemical action according to the charge amount. Therefore, it is desirable to apply control based on the current integration value of the storage battery. Thus, in the example shown in FIG. 5B, the power storage side charge / discharge control unit 118, which is the final control stage, is composed of a primary side current control system, and is the current command value I1 on the DC power storage device 4 side, that is, the primary side, generated based on the first command value and the second command value. * is input. The power storage side charge / discharge control unit 118 generates control signals SW11 - SW14, SW21 - SW24 so that the error between the value of the primary side current I1 and the primary side current command value I1 * approaches zero.

[0069] Note that FIG. 5B also shows a configuration example when a solar power generation panel is connected instead of the DC power storage device 4. When a solar power generation panel is connected, the DC / DC converter controller 110 may include a maximum power point tracking control unit 119 that executes maximum power point tracking control as described in FIG. 1. The maximum power point tracking control unit 119 is composed of, for example, a primary side voltage control system, inputs the primary side voltage V1 and the primary side current I1, and generates a primary side voltage command value V1 * . The power storage side charge / discharge control unit 118 controls so that the error between the value of the primary side voltage V1 and the primary side voltage command value V1 * approaches zero.

[0070] <Operation details of the power flow simulation unit> FIG. 6 is a schematic diagram showing an example of an electric circuit model constructed by the power flow simulation unit 66 in FIG. 4. In FIG. 6, a circuit model is shown in the mesh-shaped power distribution path shown in FIG. 2 when all the DC switches 5 are in the closed state. The power flow simulation unit 66 uses such a circuit model to predict and calculate, for example, the influence of the voltage of the DC distribution board 1 on the power flow of the DC wiring LNd.

[0071] In FIG. 6, as in the case of FIG. 2, four DC distribution boards 1A, 1B, 1C, and 1D are provided, and by connecting them to each other by five DC wirings LNd, two DC loop wirings LP1 and LP2 having a triangular shape are formed on the mesh. The voltages of the DC branch parts 10 in the four DC distribution boards 1A, 1B, 1C, and 1D are given by Va, Vb, Vc, and Vd, respectively. The resistance values of the five DC wirings LNd are given by Ra, Rb, Rc, Rd, and Re, respectively.

[0072] Also, the power balances of the DC loop wirings in the four DC distribution boards 1A, 1B, 1C, and 1D are given by Pa, Pb, Pc, and Pd, respectively. The power balance is the power corresponding to the difference between the power inflow by the DC distributed power source 3 and the power consumption by the DC load 2, or the difference between the charge and discharge power of the DC energy storage device 4 and the power consumption by the DC load 2.

[0073] FIG. 7 is a schematic diagram showing an example of the power flow change when the parameter values are changed in the electric circuit model shown in FIG. 6. In FIG. 7, the powers Pa, Pb, Pc, and Pd in FIG. 6 are shown as bar graphs, and the voltages Va, Vb, Vc, and Vd are shown as line graphs. In case A in FIG. 7, under the condition that the impedances of the respective DC wirings LNd, here the resistance values, are the same, for example, the generated power of power Pa is generated in the DC distribution board 1A, and the consumed power of power Pd is generated in the DC distribution board 1D.

[0074] On the other hand, in Case B in Fig. 7, with Case A as the reference, in DC switchboard 1B, power Pb is discharged from DC energy storage device 4, and in DC switchboard 1C, power Pc is charged to DC energy storage device 4. As can be seen from the comparison between Case A and Case B, although powers Pa, Pd and voltages Va, Vd are common, by operating powers Pb and Pc, a situation can be created where voltage Va and voltage Vb are substantially the same, and voltage Vc and voltage Vd are substantially the same.

[0075] Thus, by operating the DC power in the DC switchboard 1 of the entire system, the voltage between two terminals in DC switch 5 inserted in any DC wiring LNd can be made closer, and the power flow of the DC wiring LNd can be restricted. Thereby, for example, when changing the DC switch 5 from the closed state to the open state, the energizing current of the DC switch 5 can be reduced and ideally made zero. For this reason, damage caused by the generation of an arc or the like accompanying the opening operation of the DC switch 5 can be reduced, and the life of the DC switch 5 can be extended.

[0076] As a specific example, in Case B, the DC switches 5 (not shown) respectively provided between DC switchboard 1A and DC switchboard 1B, and between DC switchboard 1C and DC switchboard 1D in Fig. 6 can be changed from the closed state to the open state. Even in this case, since the mesh-shaped power distribution path is used, the power distribution path to the DC load 2 (not shown) connected to each DC switchboard 1 is maintained.

[0077] Here, the change from the closed state to the open state is taken as an example, but the change from the open state to the closed state is the same. That is, by changing from the open state to the closed state with the voltage between two terminals in the DC switch 5 made closer, damage caused by the inrush current or the like accompanying the closing operation of the DC switch 5 can also be reduced. Also, the state where the energizing current of the DC switch 5 is zero is equivalent to the DC switch 5 being in the open state. Therefore, from another perspective, it is also possible to switch the power distribution path of the mesh-shaped power distribution path without the opening and closing operation of the DC switch 5. In this case, since the number of opening and closing operations of the DC switch 5 can be reduced, the life of the DC switch 5 can be extended.

[0078] As an example of the actual operation method, first, based on the prediction calculation result in the power flow simulation unit 66 in FIG. 4, it is determined that it is better to change the opening / closing state of the predetermined DC switch 5. In this case, before the opening / closing operation unit 67 outputs an opening / closing command to the predetermined DC switch 5, it outputs the information of the opening / closing command to the voltage adjustment unit 68. The voltage adjustment unit 68 uses the power flow simulation unit 66 to adjust the power flow so as to reduce the voltage difference between the two terminals of the predetermined DC switch 5 as a preliminary operation for the opening operation or closing operation of the predetermined DC switch 5.

[0079] At this time, the voltage adjustment unit 68 outputs a voltage adjustment command value ΔV representing the amount of voltage adjustment to the bidirectional DC / DC converter via the distribution board controller 14 so as to change the voltage Vb in case A to the voltage Vb in case B, for example. * Similarly, the voltage adjustment unit 68 outputs the voltage adjustment command value ΔV to the bidirectional DC / DC converter via the distribution board controller 14 so as to change the voltage Vc in case A to the voltage Vc in case B. * is output.

[0080] In case C in FIG. 7, different from case A, the impedance of each DC wiring LNd, here the resistance value, is non-uniform. In case C, for example, in the DC distribution board 1A, the DC distributed power source 3 generates a generated power of Pa, and in the DC distribution board 1D, the DC load 2 consumes a power of Pd. Further, in the DC distribution board 1B, charging of the power Pb to the DC energy storage device 4 is performed, and in the DC distribution board 1C, discharging of the power Pc from the DC energy storage device 4 is performed. On the other hand, in case D, different from case C, discharging of the power Pb is performed in the DC distribution board 1B, and charging of the power Pc is performed in the DC distribution board 1C.

[0081] As can be seen from the comparison between Case C and Case D, while the powers Pa, Pd and voltages Va, Vd are substantially common, by changing the powers Pb and Pc, it is possible to mainly reduce the potential difference between the voltage Va and the voltage Vb, and the potential difference between the voltage Vb and the voltage Vc. As a result, the power loss in the entire system can be reduced. In this example, it is possible to reduce the wiring loss of the DC wiring LNd connecting the DC switchboard 1B and the DC switchboard 1C, and particularly, the DC wiring LNd having a high resistance value connecting the DC switchboard 1A and the DC switchboard 1B. In this way, the power flow control device 6 can adjust the power flow so as to reduce the power loss on the power distribution path from the DC distributed power source 3 to the DC load 2 via the DC wiring LNd.

[0082] <Details of the noise detection unit> FIGS. 8A, 8B, 8C, 8D and 8E are schematic diagrams for explaining an example of the detection algorithm of the noise detection unit 65 in FIG. 4. In the example shown in FIG. 8A, a DC loop wiring LP is formed by a pair of DC wirings LNd-PN connecting four DC switchboards 1. The pair of DC wirings LNd-PN is composed of a positive-polarity DC wiring LNd-P and a negative-polarity LNd-N.

[0083] When the magnetic field lines change in the direction penetrating such a DC loop wiring LP, for example, as shown in FIG. 8B, noise currents of the same phase are generated in both the positive-polarity DC wiring LNd-P and the negative-polarity DC wiring LNd-N. For example, a noise current IA1P on the positive-polarity side and a noise current IA1N on the negative-polarity side that is in the same phase as it are generated. Here, if the noise current on the positive-polarity side and the noise current on the negative-polarity side are added, as shown in FIG. 8C, a noise current of the same phase, for example, "1A1P + 1A1N" can be extracted.

[0084] Specifically, for example, the tidal current state acquisition unit 64 in FIG. 4 acquires the current on the positive electrode side and the current on the negative electrode side from a certain DC switchboard 1, and the noise detection unit 65 adds the current on the positive electrode side and the current on the negative electrode side. The alternating current obtained by such addition, for example, "1A1P + 1A1N", becomes the in-phase noise current. That is, in the case of normal current, unlike the in-phase noise current, the addition result of the current on the positive electrode side and the current on the negative electrode side is zero in terms of alternating current.

[0085] Furthermore, the noise detection unit 65 calculates the in-phase noise current for two or more DC wiring pairs LNd-PN forming the DC loop wiring LP, and correlates the two or more calculated in-phase noise currents. As a result, when there is a correlation, the noise detection unit 65 can determine that the in-phase noise current is a reflux current generated by electromagnetic induction. In the examples shown in FIGS. 8A and 8C, since there is a correlation between the in-phase noise current "1A1P + 1A1N" in a certain DC switchboard 1 and the in-phase noise current "1B1P + 1B1N" in another DC switchboard 1, the noise detection unit 65 determines that the in-phase noise current is a reflux current.

[0086] Also, when the frequencies that can be assumed as noise in advance can be specified, instead of performing the current addition as shown in FIG. 8C, the noise detection unit 65 may perform a filter process for extracting the frequency component on one of the positive electrode side or the negative electrode side, for example, "1A1P", as shown in FIG. 8D. Thereby, the noise detection unit 65 can extract a noise current "1A1P_fil" as shown in FIG. 8E. Then, the noise detection unit 65 extracts the noise current for two or more DC wirings LNd forming the DC loop wiring LP in the same manner as in the case of FIG. 8C, and may correlate the two or more noise currents, for example, "1A1P_fil" and "1B1P_fil".

[0087] In this way, by detecting noise currents from two or more DC wirings LNd or DC wiring pairs LNd-PN and taking the correlation of the two or more detected noise currents, it is possible to more reliably determine whether the noise current is a reflux current. And when it is a reflux current, measures such as changing a part of the DC switch 5 of the DC loop wiring LP to an open state, or correcting the acquired data for the data acquired from the DC switchboard 1 on the DC loop wiring LP can be taken.

[0088] Note that when extracting the noise current, in order to exclude noise whose influence can be ignored, an amplitude threshold may be set in advance, and the noise detection unit 65 may be configured to ignore a current having an amplitude smaller than the threshold. Or, a threshold may be set for the amount of change in current over time, and the noise detection unit 65 may be configured to ignore a current having an amount of change over time smaller than the threshold.

[0089] <Main effects of the first embodiment> As described above, in the method of the first embodiment, a DC loop wiring that circulates through two or more DC switchboards is formed. Desirably, a mesh-shaped power distribution path is constructed by arranging a plurality of DC loop wirings in a lattice shape or a mesh shape. By using such a configuration, a power distribution path can be flexibly constructed according to the configuration or situation of the facility. Also, with two or more DC switchboards, the power flow on the DC wiring connecting between the DC switchboards can be adjusted. Thereby, for example, damage associated with the opening and closing operation of the DC switch inserted into the DC wiring can be reduced.

[0090] (Second embodiment) <Application example of DC power distribution system> FIG. 9 is a perspective view showing an example of an arrangement configuration when applied to a facility in the DC power distribution system according to the second embodiment. In FIG. 9, for example, an example of the arrangement configuration of each part when the DC power distribution system described in the first embodiment is laid on the floor of a facility such as a production factory is shown. In FIG. 9, four DC switchboards 1E, 1F, 1G, and 1H are arranged at the four corners of a lattice, for example, a rectangle. In the entire facility, such lattices are arranged in sequence in the X-axis direction and the Y-axis direction.

[0091] The four DC distribution boards 1E, 1F, 1G, and 1H are connected via four DC wiring lines LNd corresponding to the four sides of the grid. The DC wiring lines LNd are laid, for example, as ceiling-suspended wiring racks. Note that the DC wiring lines LNd may have a structure such as a bus duct in addition to cables. On the other hand, for example, DC loads 2E, 2F, 2G, and 2H such as manufacturing devices are each connected to the DC distribution boards 1E, 1F, 1G, and 1H via load power lines LNl laid in pits on the floor surface or the like. By using such an arrangement configuration example, for example, a DC power distribution system suitable for the vertical arrangement inside the DC distribution board 1 shown in FIG. 3 can be constructed.

[0092] Also, four DC switches 5EF, 5FH, 5GH, and 5EG are inserted into the four DC wiring lines LNd, respectively. At this time, each DC switch 5 is preferably arranged near the DC distribution board 1 so that the operation by the DC distribution board 1 becomes easy. Further, each DC distribution board 1, specifically, the distribution board controller 14, is preferably configured so that the number of the above-described DC switch operation circuits, for example, driver circuits, can be increased. Furthermore, each DC distribution board 1 is preferably configured so that the number of the first current sensors 12G shown in FIG. 3 for measuring the current of the DC wiring line LNd can be increased.

[0093] Generally, in a production factory or the like, since straight lines are frequently used as the flow lines of transport machinery, it is desirable that the DC distribution boards 1 be arranged in a grid pattern with a square as the standard as shown in FIG. 9. Therefore, in the DC distribution board 1 at the intersection of the grid, the maximum number of DC switch operation circuits that can be mounted can be four. Similarly, in the DC distribution board 1, the maximum number of current sensors 12G that can be mounted can also be four.

[0094] FIG. 10A is a plan view showing a schematic arrangement configuration example when the DC power distribution system shown in FIG. 9 is viewed from above. In FIG. 10A, the grid is composed of quadrilaterals in the XY plane as described above. In this case, it is not necessary for all the DC distribution boards 1 to drive the DC switch 5, and it is sufficient for the DC distribution boards 1 determined according to a certain criterion to drive the DC switch 5. Similarly, it is not necessary for all the DC distribution boards 1 to measure the current flowing through the DC wiring LNd, and it is sufficient for the DC distribution boards 1 determined according to a certain criterion to measure the current flowing through the DC wiring LNd.

[0095] Here, as a certain criterion, in at least a part of the region, the first group of DC distribution boards 1a shown in black and the second group of DC distribution boards 1b shown in white are alternately arranged on the XY plane. The first group of DC distribution boards 1a drive the DC switch 5 and measure the current flowing through the DC wiring LNd. On the other hand, the second group of DC distribution boards 1b do not drive the DC switch 5 and do not measure the current flowing through the DC wiring LNd.

[0096] By providing such a certain criterion, for example, the opening and closing management of the DC switch 5 can be facilitated, and the current flowing through the DC wiring LNd does not need to be measured repeatedly. Furthermore, the second group of DC distribution boards 1b do not particularly need to be equipped with a DC switch operation circuit, nor do they need to be equipped with the first current sensor 12G. Thereby, the component cost can be reduced. Regarding the DC wiring LNd between the DC distribution boards 1, as shown by the area 102, the power transmission capacity between the DC distribution boards 1 may be configured to be expanded by connecting two systems of DC wiring in parallel to the DC branch section 10.

[0097] FIG. 10B is a plan view showing an arrangement configuration example in which the arrangement shown in FIG. 10A is deformed. In FIG. 10B, the grid is composed of a hexagon including at least one pair of parallel sides. In this case, the DC distribution board 1 drives a maximum of three DC switches 5 and measures the current flowing through a maximum of three DC wirings LNd. Also in FIG. 10B, as in the case of FIG. 10A, in at least a part of the region, the first group of DC distribution boards 1a and the second group of DC distribution boards 1b are alternately arranged on the XY plane.

[0098] The invention made by the inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist thereof. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Also, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, for a part of the configuration of each embodiment, addition, deletion, or replacement with other configurations is possible.

Explanation of Reference Numerals

[0099] 1: DC distribution board, 2: DC load, 3: DC distributed power source, 4: DC energy storage device, 5: DC switch, 6: Distribution system control device, 10: DC branch section, 11: DC / DC converter, 12: Current sensor, 13: DC circuit breaker, 14: Distribution board controller, 17: Housing, 18: Wiring hole, 61: Wiring information storage section, 63: Opening / closing state acquisition section, 64: Power flow state acquisition section, 65: Noise detection section, 66: Power flow simulation section, 68: Voltage adjustment section, LNd: DC wiring, LNl: Load power line, LNp: Power source wiring, LP: DC loop wiring

Claims

1. A plurality of DC distribution boards for distributing the input DC power, A DC wiring for transmitting the DC power among the plurality of DC distribution boards, A power distribution system control device for overall controlling the plurality of DC distribution boards, A DC power distribution system comprising: The DC wiring forms a DC loop wiring by making a round through at least two or more of the plurality of DC distribution boards, A first DC distribution board which is one of the plurality of DC distribution boards has a bidirectional DC / DC converter, and a DC power storage device for storing the DC power is configured to be connectable via the bidirectional DC / DC converter, The power distribution system control device adjusts the power flow on the DC wiring by controlling the bidirectional DC / DC converter. DC power distribution system.

2. The DC power distribution system according to Claim 1, Further comprising a DC switch inserted into the DC wiring and configured to be openable and closable between two terminals, The power distribution system control device adjusts the power flow so as to reduce the voltage difference between the two terminals as a preliminary operation of the open operation or the close operation of the DC switch. DC power distribution system.

3. The DC power distribution system according to Claim 1, A second DC distribution board which is another one of the plurality of DC distribution boards has a DC / DC converter, and a DC distributed power source for generating power is configured to be connectable via the DC / DC converter, At least one of the plurality of DC distribution boards is configured to be connectable to a DC load via a DC circuit breaker that shuts off the path when an abnormal current is detected, The power distribution system control device adjusts the power flow so as to reduce the power loss on the power distribution path from the DC distributed power source to the DC load via the DC wiring. DC power distribution system.

4. In the DC power distribution system according to claim 2, the power distribution system control device includes a wiring information storage unit that holds information on the connection relationship via the DC wiring between the plurality of DC distribution boards; a power flow state acquisition unit that acquires power flow information of the DC wiring; an opening / closing state acquisition unit that acquires the opening / closing state of the DC switch; based on the information held in the wiring information storage unit and the information acquired by the power flow state acquisition unit and the opening / closing state acquisition unit, constructs an electrical circuit model and parameters representing voltage values, current values, or power values on the electrical circuit model, and a power flow simulation unit that predicts and calculates a power flow change when the values of the parameters are changed; a voltage adjustment unit that outputs a voltage adjustment command value representing an amount of voltage adjustment to any one of the plurality of DC distribution boards based on the prediction calculation result of the power flow simulation unit; and a DC power distribution system.

5. In the DC power distribution system according to claim 4, the power flow simulation unit predicts and calculates a power flow change when the DC voltage of any one of the plurality of DC distribution boards is changed; a DC power distribution system.

6. In the DC power distribution system according to claim 4, the power flow simulation unit predicts and calculates a power flow change and a terminal voltage change of the plurality of DC distribution boards when the DC power of the bidirectional DC / DC converter is changed; a DC power distribution system.

7. In the DC power distribution system according to claim 4, the power distribution system control device further includes a noise detection unit that detects that noise current is superimposed on the DC loop wiring based on the information acquired by the opening / closing state acquisition unit and the power flow state acquisition unit; DC power distribution system.

8. In the DC power distribution system according to claim 7, when the power distribution system control device detects noise by the noise detection unit, the DC switch in a part of the DC loop wiring is changed to an open state. DC power distribution system.

9. In the DC power distribution system according to claim 7, when the power distribution system control device detects noise by the noise detection unit, the acquired data of the power flow state acquisition unit is corrected so as to cancel the current change caused by the noise. DC power distribution system.

10. In the DC power distribution system according to claim 7, the noise detection unit detects the noise current from two or more DC wirings forming the DC loop wiring, and when there is a correlation between the detected two or more noise currents, the noise current is determined as a reflux current associated with electromagnetic induction. DC power distribution system.

11. In the DC power distribution system according to claim 1, a plurality of the DC loop wirings are formed, at least one of the plurality of DC distribution boards is commonly connected to the plurality of DC loop wirings. DC power distribution system.

12. In the DC power distribution system according to claim 11, further, a DC switch inserted into the DC wiring and configured to be able to open and close between two terminals is provided, the plurality of DC distribution boards, a first group of DC distribution boards that drive the DC switch to open and close and measure the current flowing through the DC wiring, and a second group of DC distribution boards that do not drive the DC switch to open and close and do not measure the current flowing through the DC wiring, are included, The DC switchboards of the first group and the DC switchboards of the second group are arranged alternately. DC power distribution system.

13. A DC switchboard composed of one housing that houses a plurality of components, The plurality of components include: A DC branch part connected to a plurality of DC wiring drawn out to the outside and composed of a conductive material, A bidirectional DC / DC converter connected to the DC branch part via a power supply wiring, A DC power storage device that stores DC power and is connected to the DC branch part via the bidirectional DC / DC converter, A DC circuit breaker inserted into a load power line that connects the DC branch part and a DC load provided outside, and cuts off the path of the load power line when an abnormal current is detected, A first current sensor that measures the current of each of the plurality of DC wiring, A second current sensor that measures the current of the load power line, A third current sensor that measures the current of the power supply wiring, A switchboard controller that controls the DC switchboard including the control of the bidirectional DC / DC converter, and include Any one of the plurality of DC wiring is connected to any other one of the plurality of DC wiring via an external wiring path. DC switchboard.

14. In the DC switchboard according to claim 13, On the premise that a DC switch that is configured to be able to open and close between two terminals is inserted into at least any one of the plurality of DC wiring, The switchboard controller includes a DC switch operation circuit that drives the DC switch to open and close. DC switchboard.

15. In the DC switchboard according to claim 13, When the relative positional relationship in the direction perpendicular to the ground is defined as upward and downward, the housing is provided with a first wiring hole for drawing out the plurality of DC wirings to the outside above, and a second wiring hole for drawing out the load power line to the outside below. DC distribution board. Claim 16 In the DC distribution board according to claim 15, the DC branch portion, the bidirectional DC / DC converter, and the DC power storage device are arranged in order from above to below. DC distribution board.

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