JP6273708B2 - Electric power network system, electric power router and its management device, operation method and operation program - Google Patents

Description

  The present invention relates to a power network system configured by asynchronously connecting a plurality of power cells to each other, a power router and its management device, an operation method, and an operation program, and more particularly to operate a device built in the power router. The present invention relates to a power network system, a power router, a management device thereof, an operation method, and an operation program.

  In constructing a power supply system, not only will the power transmission network be expanded more stably, but in the future it will become an important issue to make the system capable of introducing a large amount of natural energy. Therefore, a power network system called Digital Grid (registered trademark) has been proposed as a new power network (Patent Literature 1: Patent No. 4783453, Non-Patent Literature 1: Refer to the website of the Digital Grid Consortium, http: //www.digitalgrid). .Org / index.php / jp /). Digital Grid (registered trademark) is a power network system in which a power network is subdivided into small cells and these are interconnected asynchronously. Each power cell is a small house, a building, or a commercial facility, and a large one is a prefecture or a municipality. Each power cell may have a load therein, as well as a power generation facility and a power storage facility. Examples of power generation facilities include power generation facilities that use natural energy such as solar power generation, wind power generation, and geothermal power generation.

The power cells are connected asynchronously in order to freely generate power within each power cell and to allow the power cells to smoothly pass power. (That is, even if a plurality of power cells are connected to each other, the voltage, phase and frequency of power used in each power cell are asynchronous with the other power cells.)
FIG. 40 shows an example of the power network system 10. In FIG. 40, the backbone system 11 transmits the backbone power from the large-scale power plant 12. A plurality of power cells 21-24 are arranged. Each power cell 21-24 has loads such as a house 31 and a building 32, power generation facilities 33 and 34, and a power storage facility 35. Examples of power generation facilities include a solar power generation panel 33 and a wind power generator 34. The power storage facility is a storage battery 35 or the like. In this specification, the power generation facility and the power storage facility may be collectively referred to as a distributed power source.

Furthermore, each power cell 21-24 includes power routers 41-44 that serve as connection ports (connection ports) for connection to other power cells and the backbone system 11. The power routers 41-44 have a plurality of legs (LEGs). (For convenience of paper width, the reference numerals of the legs are omitted in FIG. 40. Interpret the white circles attached to the power routers 41-44 as the connection terminals of each leg.)
Here, a leg has a connection terminal and a power converter, and an address is given to each leg. In addition, the power conversion by a leg means changing from alternating current to direct current or from direct current to alternating current, and changing the voltage, frequency, and phase of electric power.

  All the power routers 41-44 are connected to the management server 50 by the communication network 51, and all the power routers 41-44 are integrated and controlled by the management server 50. For example, the management server 50 instructs each power router 41-44 to transmit or receive power for each leg by using the address assigned to each leg. Thereby, power interchange between power cells is performed via the power routers 41-44.

  By realizing power interchange between the power cells, for example, one power generation facility 33, 34 and one power storage facility 35 can be shared by a plurality of power cells. If surplus power can be interchanged between power cells, the power supply / demand balance can be stably maintained while greatly reducing the equipment cost.

Japanese Patent No. 4783453

Digital Grid Consortium, [November 28, 2012 search], Internet <URL: http: // www. digitalgrid. org / index. php / jp />

If a plurality of power cells can be connected asynchronously by the power router, the advantage is very great, and it is expected that the power router will be put into practical use at an early stage.
However, when power routers are actually put into practical use, unique problems that have not existed in conventional power transmission and distribution facilities become apparent. In order to continue maintaining the function of the power router, it is necessary to assign a specific role to a part of the legs included in the power router. However, the leg selection method for that specific role has not yet been established.

  The present invention has been made to solve such problems, and a power network system that defines a guideline for selecting a leg that plays a specific role from among a plurality of legs in a power router, and It is an object of the present invention to provide a power router, its management device, operation method, and operation program.

The power router according to the first aspect of the present invention includes:
A power router for asynchronously connecting power cells to an external power system,
A DC bus maintained at a predetermined rated voltage;
One connection end is connected to the DC bus, the other connection end is connected to an external connection partner as an external connection terminal, and a plurality of powers are converted between the one connection end and the other connection end. A power conversion leg,
A controller that controls the power conversion leg in a predetermined operation mode,
The operation mode includes a master mode that is an operation mode for operating the power conversion leg so that the voltage of the DC bus is maintained at the predetermined rated voltage,
The control unit controls operation of at least one of the plurality of power conversion legs in the master mode,
Each of the plurality of power conversion legs is associated with an index value indicating the possibility that the operation mode of the power conversion leg becomes the master mode.

A power network system according to a second aspect of the present invention includes:
A power network system comprising a plurality of power cells having a power router for asynchronously connecting to an external power system,
The power router
A DC bus maintained at a predetermined rated voltage;
One connection end is connected to the DC bus, the other connection end is connected to an external connection partner as an external connection terminal, and a plurality of powers are converted between the one connection end and the other connection end. A power conversion leg,
A controller that controls the power conversion leg in a predetermined operation mode,
The operation mode includes a master mode that is an operation mode for operating the power conversion leg so that the voltage of the DC bus is maintained at the predetermined rated voltage,
The control unit controls operation of at least one of the plurality of power conversion legs in the master mode,
Each of the plurality of power conversion legs is associated with a first index value indicating the possibility that the operation mode of the power conversion leg becomes the master mode.

The power router management apparatus according to the third aspect of the present invention includes:
A DC bus maintained at a predetermined rated voltage, one connection end is connected to the DC bus, the other connection end is connected to an external connection partner as an external connection terminal, the one connection end and the other connection end A management device that manages a power router comprising a plurality of power conversion legs that convert power to and from a connection end, and a control unit that controls operation of the power conversion legs in a predetermined operation mode,
Connected to a plurality of power cells having the power router via a network;
The operation mode includes a master mode that is an operation mode for operating the power conversion leg so that the voltage of the DC bus is maintained at the predetermined rated voltage,
Based on an index value indicating the possibility that the operation mode becomes the master mode and associated with each of the plurality of power conversion legs, the master mode is selected from the plurality of power conversion legs. Select at least one power conversion leg to control the operation with
The power router is instructed to control operation of the selected power conversion leg in the master mode.

The operation method of the power router according to the fourth aspect of the present invention is as follows:
A DC bus maintained at a predetermined rated voltage, one connection end is connected to the DC bus, the other connection end is connected to an external connection partner as an external connection terminal, the one connection end and the other connection end In a power router comprising a plurality of power conversion legs that convert power to and from a connection end, and a control unit, an operation method of a power router that controls operation of each power conversion leg in a predetermined operation mode,
The operation mode includes a master mode that is an operation mode for operating the power conversion leg so that the voltage of the DC bus is maintained at the predetermined rated voltage,
Based on an index value indicating the possibility that the operation mode becomes the master mode and associated with each of the plurality of power conversion legs, the master mode is selected from the plurality of power conversion legs. Select at least one power conversion leg to control the operation with
Operation of the selected power conversion leg is controlled in the master mode.

The operation program of the power router according to the fifth aspect of the present invention is:
A DC bus maintained at a predetermined rated voltage, one connection end is connected to the DC bus, the other connection end is connected to an external connection partner as an external connection terminal, the one connection end and the other connection end In a power router comprising a plurality of power conversion legs that convert power to and from a connection end, and a control unit, an operation program for a power router that controls operation of each power conversion leg in a predetermined operation mode,
The operation mode includes a master mode that is an operation mode for operating the power conversion leg so that the voltage of the DC bus is maintained at the predetermined rated voltage,
Based on an index value indicating the possibility that the operation mode becomes the master mode and associated with each of the plurality of power conversion legs, the master mode is selected from the plurality of power conversion legs. A process of selecting at least one power conversion leg to be operated and controlled by
Processing for controlling the selected power conversion leg in the master mode;
Is executed by the control unit.

  According to the present invention, in order to continue to maintain the function of the power router, the power network system, the power router, and the management of the power network system in which a guideline for selecting a leg having a specific role is selected from a plurality of legs in the power router. An apparatus, an operation method, and an operation program can be provided.

It is a block diagram which shows schematic structure of the power router concerning each embodiment of this invention. It is a block diagram which shows in detail the internal structure of the electric power router concerning each embodiment of this invention. It is a figure which shows an example which connected the power router to the trunk system, load, and various distributed power supplies. It is a figure which shows the example of a possible combination in the connection of electric power routers. It is a figure which shows the example of a possible combination in the connection of electric power routers. It is a figure which shows the example of the combination prohibited in the connection of electric power routers. It is a figure which shows the example of the combination prohibited in the connection of electric power routers. It is a figure which shows the example of the combination prohibited in the connection of electric power routers. It is a figure which shows the example of the combination prohibited in the connection of electric power routers. It is a figure which shows the example of the possible combination in the connection of power routers when AC through leg is taken into consideration. It is a figure which shows the example of the possible combination in the connection of power routers when AC through leg is taken into consideration. It is a figure which shows the example of the possible combination in the connection of power routers when AC through leg is taken into consideration. It is a figure which shows the example of the possible combination in the connection of power routers when AC through leg is taken into consideration. It is a figure which shows the example of a connection using AC through leg. It is the figure which put together the pattern of the combination in the connection between electric power routers. An example in which four power routers are connected to each other will be given. It is a figure which shows an example of a mode that several electric power routers were bus-connected. It is a figure which shows an example of the connection form which the backbone system intervened between the power routers. It is a block diagram which shows the structure of the electric power network system containing the electric power router and management server concerning Embodiment 1 of this invention. It is a block diagram which shows the structure of the management apparatus concerning Embodiment 1 of this invention. It is a flowchart which shows the flow of the driving | operation process of the electric power router concerning Embodiment 1 of this invention. It is a block diagram which shows the structure of the electric power network system containing the electric power router and management server concerning Embodiment 2 of this invention. It is a figure which shows the example of the priority table concerning Embodiment 2 of this invention. It is a figure which shows the example of the priority table containing the exclusion value concerning Embodiment 2 of this invention. It is a figure which shows the example of the initial value of the priority table concerning Embodiment 3 of this invention. It is a flowchart which shows the flow of the priority update process concerning Embodiment 3 of this invention. It is a flowchart which shows the flow of the master leg switching process concerning Embodiment 3 of this invention. It is a figure which shows the example of the assignment of the priority concerning Embodiment 4 of this invention. It is a figure which shows the example of the assignment of the priority concerning Embodiment 4 of this invention. It is a figure which shows the example of the priority table concerning Embodiment 4 of this invention. It is a block diagram which shows the structure of the electric power network system containing the electric power router and management server concerning Embodiment 5 of this invention. It is a figure which shows the example of the leg information table concerning Embodiment 5 of this invention. It is a flowchart which shows the flow of the driving | running | working process of the electric power router concerning Embodiment 5 of this invention. It is a figure which shows the concept of the determination of a leg candidate in the case of emphasizing the priority table concerning Embodiment 5 of this invention. It is a flowchart which shows the flow of the driving | operation process of the electric power router concerning Embodiment 6 of this invention. It is a figure which shows the concept of the determination of a leg candidate in the case of emphasizing the output possible power of the leg concerning Embodiment 6 of this invention. It is a figure which shows the concept of the determination of a leg candidate in the case of emphasizing the output possible power of the leg concerning Embodiment 6 of this invention. It is a figure which shows the concept of the determination of a leg candidate in the case of fixing the number of leg candidates concerning Embodiment 6 of this invention. It is a figure which shows the concept of the determination of a leg candidate in the case of emphasizing the number of leg candidates concerning Embodiment 7 of this invention. It is a figure for demonstrating the system outline | summary of an electric power network system.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. In the drawings, the same elements are denoted by the same reference numerals, and redundant description will be omitted as necessary for the sake of clarity. In the following, “connection partner” refers to a connection destination of a leg.

First, the configuration of the power router common to each embodiment of the present invention will be described.
FIG. 1 is a diagram showing a schematic configuration of the power router 100.
FIG. 2 is a diagram showing the internal configuration of the power router 100 in some detail.
The power router 100 generally includes a DC bus 101, a plurality of legs 110-160, and a control unit 190.

The power router 100 has a DC bus 101, and a plurality of legs 110-160 are connected to the DC bus 101 in parallel. The DC bus 101 is for flowing DC power, and is controlled so that the voltage of the DC bus 101 is kept at a predetermined level.
(How the voltage of the DC bus 101 is kept constant will be described later.)
Although the power router 100 is connected to the outside via each leg 110-160, all the power exchanged with the outside is once converted into direct current and placed on the direct current bus 101. Thus, once through the direct current, the difference in frequency, voltage, and phase becomes irrelevant, and the power cells can be connected asynchronously. Here, it is assumed that the DC bus 101 is a parallel type having a smoothing capacitor 102 as shown in FIG. A voltage sensor 103 is connected to the DC bus 101, and the voltage value of the DC bus 101 detected by the voltage sensor 103 is sent to the control unit 190. In addition, the control unit 190 controls the operation state of the legs 110-160 (external power transmission operation, external power reception operation, etc.) via the communication bus 104, thereby setting the voltage of the DC bus 101 to a predetermined constant value. To maintain.

  Next, the legs 110-160 will be described. A plurality of legs 110-160 are provided in parallel to the DC bus. In FIG. 1, six legs 110-160 are shown. As shown in FIG. 1, the six legs 110-160 are defined as a first leg 110, a second leg 120, and a sixth leg 160. In FIG. 1, the first leg 110 is shown as leg 1 and the second leg 120 is shown as leg 2 for the sake of paper width. Further, in FIG. 2, the third leg 130, the fourth leg 140, and the sixth leg 160 are omitted.

  While the first leg 110 to the fifth leg 150 have the same configuration, the sixth leg 160 is different from the first to fifth legs 110-150 in that it does not have a power converter. First, the configuration of the first leg 110 to the fifth leg 150 will be described. Since the first leg 110 to the fifth leg 150 have the same configuration, the configuration of the first leg 110 will be described as a representative. The first leg 110 includes a power conversion unit 111, a current sensor 112, a switch 113, a voltage sensor 114, and a connection terminal 115. The power conversion unit 111 converts AC power into DC power, or converts DC power into AC power. Since DC power is flowing through the DC bus 101, the power converter 111 converts the DC power of the DC bus 101 into AC power having a predetermined frequency and voltage, and flows the AC power from the connection terminal 115 to the outside. Alternatively, the power conversion unit 111 converts AC power flowing from the connection terminal 115 into DC power and flows the DC power to the DC bus 101.

The power conversion unit 111 has a configuration of an inverter circuit, that is, an antiparallel circuit 111P composed of a thyristor 111T and a feedback diode 111D is connected in a three-phase bridge. (That is, six antiparallel circuits 111P are provided for one inverter circuit.)
Here, since a three-phase alternating current is used, a three-phase inverter circuit is used, but a single-phase inverter circuit may be used in some cases. A wire drawn from a node between the two antiparallel circuits 111P and connecting the node and the connection terminal will be referred to as a branch line BL. (Because it is a three-phase AC, one leg has three branch lines BL.)

  The direction of power, the frequency of AC power, and the like are controlled by the control unit 190. That is, the switching of the thyristor 111T is controlled by the control unit 190. Operation control by the control unit 190 will be described later.

  A switch 113 is disposed between the power conversion unit 111 and the connection terminal 115. By opening / closing the switch 113, the branch line BL is opened / closed, that is, the outside and the DC bus line 101 are cut off or connected. The voltage of the branch line BL is detected by the voltage sensor 114, and the current value of the current flowing through the branch line BL is detected by the current sensor 112. The opening / closing operation of the switch 113 is controlled by the control unit 190, and the detection values by the voltage sensor 114 and the current sensor 112 are output to the control unit 190.

In the above description, the power conversion unit is an inverter circuit, and the connection partner of the leg uses alternating current. However, the connection partner of the leg may use direct current such as the storage battery 35 in some cases. (For example, the third leg 130 in FIG. 1 is connected to the storage battery 35.)
The power conversion in this case is DC-DC conversion. Therefore, an inverter circuit and a converter circuit may be provided in parallel in the power conversion unit, and the inverter circuit and the converter circuit may be selectively used depending on whether the connection partner is AC or DC. Or you may make it provide a leg only for DC-DC conversion whose power conversion part is a DC-DC conversion part. Rather than providing an inverter circuit and a converter circuit in parallel in all the legs, it is more advantageous in terms of size and cost to use a power router that has both a leg dedicated to AC-DC conversion and a leg dedicated to DC-DC conversion. There are many points.

  The configuration of the first leg 110 to the fifth leg 150 is as described above.

  Next, the sixth leg 160 will be described. The sixth leg 160 does not have a power conversion unit, that is, the connection terminal 165 of the sixth leg 160 is not connected to the DC bus 101. The sixth leg 160 is connected to the branch line BL of the fifth leg 150. The internal wiring of the sixth leg 160 is also referred to as a branch line BL. The branch line BL of the sixth leg 160 is connected between the connection terminal 155 of the fifth leg 150 and the switch 153 with respect to the fifth leg 150.

  The sixth leg 160 includes a switch 163, a voltage sensor 164, a current sensor 162, and a connection terminal 165. The branch line BL of the sixth leg 160 is connected to the branch line BL of the fifth leg 150 via the switch 163. That is, the connection terminal 165 of the sixth leg 160 is connected to the connection terminal 155 of the fifth leg 150. There is only a switch 163 between the connection terminal 165 of the sixth leg 160 and the connection terminal 155 of the fifth leg 150, and the sixth leg 160 does not have a power converter, so the connection terminal of the sixth leg 160 Between 165 and the connection terminal 155 of the fifth leg 150, power is conducted without undergoing any conversion. Therefore, a leg having no power converter like the sixth leg 160 may be referred to as an AC through leg.

  Current sensor 162 and voltage sensor 164 detect the current value and voltage value of branch line BL and output them to control unit 190. The opening / closing operation of the switch 163 is controlled by the control unit 190.

(Regal operation mode)
As described above, the first leg 110 to the fifth leg 150 have power converters 111-151, and the switching operation of the thyristor in the power converter is controlled by the control unit 190.
Here, the power router 100 is in a node of the power network 10 and has an important role of connecting the backbone system 11, the load 30, the distributed power source, the power cell, and the like. At this time, the connection terminals 115-165 of the legs 110-160 are respectively connected to the backbone system 11, the load 30, the distributed power source, and the power routers of other power cells. The present inventors have realized that the role of each leg 110-160 differs depending on the connection partner, and that the power router cannot be established unless each leg 110-160 performs an appropriate operation according to the role. The inventors of the present invention have the same leg structure, but change the operation of the leg depending on the connection partner.
The manner of driving the leg is referred to as an operation mode.
The present inventors prepared three types of leg operation modes, and switched the mode depending on the connection partner.
Leg operating modes include
Master mode,
Independent mode,
There are designated power transmission / reception modes.
Hereinafter, it demonstrates in order.

(Master mode)
The master mode is an operation mode when connected to a stable power supply source such as a system, and is an operation mode for maintaining the voltage of the DC bus 101. FIG. 1 shows an example in which the connection terminal 115 of the first leg 110 is connected to the backbone system 11. In the case of FIG. 1, the first leg 110 is operated and controlled as a master mode, and plays a role of maintaining the voltage of the DC bus 101. When many other legs 120-150 are connected to the DC bus 101, power may flow from the legs 120-150 to the DC bus 101, or power may flow from the legs 120-150. . When the power flows out from the DC bus 101 and the voltage of the DC bus 101 drops from the rating, the leg 110 that is in the master mode compensates for the power shortage due to the outflow from the connection partner (here, the main system 11). Alternatively, when power flows into the DC bus 101 and the voltage of the DC bus 101 rises from the rating, the excess power due to the inflow is released to the connection partner (here, the backbone system 11). In this way, the leg 110 in the master mode maintains the voltage of the DC bus 101.
Thus, in one power router, at least one leg must be operated in master mode. Otherwise, the voltage of the DC bus 101 will not be maintained constant. Conversely, two or more legs may be operated in the master mode in one power router, but it is better to have one master mode leg in one power router.
Moreover, you may connect the leg used as master mode to the distributed power supply (a storage battery is also included) which mounts a self-excited inverter other than a basic system, for example. However, a distributed power source equipped with a separately excited inverter cannot be connected to a leg that becomes a master mode.

  In the following description, a leg operated in the master mode may be referred to as a master leg.

The operation control of the master leg will be described.
When activating the master leg:
First, the switch 113 is opened (cut off). In this state, the connection terminal 115 is connected to the connection partner. Here, the connection partner is the backbone system 11.
The voltage of the connection destination system is measured by the voltage sensor 114, and the amplitude, frequency, and phase of the system voltage are obtained using a PLL (Phase-Locked-Loop) or the like. Thereafter, the output of the power conversion unit 111 is adjusted so that the voltage of the obtained amplitude, frequency, and phase is output from the power conversion unit 111. That is, the on / off pattern of the thyristor 111T is determined. When this output becomes stable, the switch 113 is turned on to connect the power conversion unit 111 and the backbone system 11. At this time, since the output of the power converter 111 and the voltage of the backbone system 11 are synchronized, no current flows.

The operation control when operating the master leg will be described.
The voltage of the DC bus 101 is measured by the voltage sensor 103. If the voltage of the DC bus 101 exceeds the predetermined rated bus voltage, the power converter 111 is controlled so that power is transmitted from the master leg 110 toward the grid. (At least one of the amplitude and phase of the voltage output from the power converter 111 is adjusted so that power is transmitted from the DC bus 101 to the backbone system 11 via the master leg 110.) The rated voltage of the bus line 101 is determined in advance by setting.

  On the other hand, if the voltage of the DC bus 101 is lower than the predetermined rated bus voltage, the power converter 111 is controlled so that the master leg 110 can receive power from the backbone system 11. (At least one of the amplitude and phase of the voltage output from the power conversion unit 111 is adjusted so that power is transmitted from the backbone system 11 to the DC bus 101 via the master leg 110.) It will be understood that the voltage of the DC bus 101 can be maintained at a predetermined rating by performing the above operation.

(Independent mode)
The self-supporting mode is an operation mode in which a voltage having an amplitude and frequency designated by the management server 50 is generated by itself and power is transmitted to and received from a connection partner.
For example, the operation mode is for supplying power toward a power consuming device such as the load 30. Or it becomes an operation mode for receiving the electric power transmitted from the connection partner as it is.
FIG. 1 shows an example in which the connection terminal 125 of the second leg 120 is connected to the load 30. The second leg 120 is controlled to operate in the self-supporting mode, and power is supplied to the load 30.
In addition, when connected to another power router, such as the fourth leg 140 or the fifth leg 150, the fourth leg 140 or the fifth leg is used as a mode for transmitting the power required by the other power router. In some cases, 150 is operated in a self-supporting mode.
Alternatively, when connected to another power router like the fourth leg 140 or the fifth leg 150, the fourth leg 140 or the fifth leg is set as a mode for receiving the power transmitted from the other power router. In some cases, 150 is operated in a self-supporting mode.
Although not shown in the figure, the second leg can be operated in the self-supporting mode even when the second leg is connected to the power generation facility instead of the load 30. However, in this case, a separately-excited inverter is mounted on the power generation facility.
The operation mode when connecting power routers will be described later.

  A leg operated in the self-supporting mode is referred to as a self-supporting leg. There may be a plurality of independent legs in one power router.

The operation control of the independent leg will be described.
First, the switch 123 is opened (shut off). The connection terminal 125 is connected to the load 30. The management server 50 instructs the power router 100 on the amplitude and frequency of power (voltage) to be supplied to the load 30. Therefore, the control unit 190 causes the power (voltage) having the instructed amplitude and frequency to be output from the power conversion unit 121 toward the load 30. (That is, the on / off pattern of the thyristor 121T is determined.) When this output becomes stable, the switch 123 is turned on and the power converter 121 and the load 30 are connected. After that, if power is consumed by the load 30, the corresponding power flows from the self-supporting leg 120 to the load 30.

(Designated power transmission / reception mode)
The designated power transmission / reception mode is an operation mode for exchanging the power determined by the designation. That is, there are a case where the designated power is transmitted to the connection partner and a case where the designated power is received from the connection partner.
In FIG. 1, the fourth leg 140 and the fifth leg 150 are connected to other power routers.
In such a case, a predetermined amount of power is interchanged from one to the other.
Alternatively, the third leg 130 is connected to the storage battery 35.
In such a case, a predetermined amount of power is transmitted to the storage battery 35 and the storage battery 35 is charged.
Further, a distributed power source (including a storage battery) equipped with a self-excited inverter and a designated power transmission / reception leg may be connected. However, a distributed power source equipped with a separately-excited inverter cannot be connected to a designated power transmission / reception leg.

  A leg operated in the designated power transmission / reception mode is referred to as a designated power transmission / reception leg. In one power router, there may be a plurality of designated power transmission / reception legs.

  The operation control of the designated power transmission / reception leg will be described. Since the control at the time of starting is basically the same as that of the master leg, it is omitted.

The operation control when operating the designated power transmission / reception leg will be described.
(In the description, the reference numerals attached to the fifth leg 150 are used.)
The voltage of the connection partner system is measured by the voltage sensor 154, and the frequency and phase of the connection partner voltage are obtained using a PLL (Phase-Locked-Loop) or the like. Based on the active power value and reactive power value specified from the management server 50 and the frequency and phase of the voltage of the connection partner, the target value of the current input / output by the power converter 151 is obtained. The current value of the current is measured by the current sensor 152. The power converter 151 is adjusted so that a current corresponding to the difference between the target value and the current value is additionally output. (At least one of the amplitude and phase of the voltage output from the power converter 151 is adjusted so that desired power flows between the designated power transmission / reception leg and the connection partner.)

  From the above description, it will be understood that the first to fifth legs having the same configuration can play the role of three patterns depending on the manner of operation control.

(Connection restrictions)
Since the operation of the leg differs depending on the operation mode, a restriction naturally occurs between the selection of the connection partner and the selection of the operation mode. That is, the operation mode that can be selected is determined when the connection partner is determined, and conversely, the connection partner that can be selected is determined when the operation mode is determined. (If the connection partner changes, the leg operation mode must be changed accordingly.)
A possible connection combination pattern will be described.

In the following description, the notation in the figure is simplified as shown in FIG.
That is, the master leg is represented by M.
The self-supporting leg is represented by S.
The designated power transmission / reception leg is represented by D.
AC through leg is represented by AC.
Further, the legs may be distinguished by attaching a number such as “# 1” to the shoulders of the legs as necessary.
Further, in FIG. 3 and subsequent figures, systematic symbols are assigned for each drawing, but the same symbols are not necessarily assigned to the same elements across the drawings.
For example, the reference numeral 200 in FIG. 3 and the reference numeral 200 in FIG. 4 do not indicate exactly the same thing.

The connection combinations shown in FIG. 3 are all possible connections. The first leg 210 is connected to the backbone system 11 as a master leg. This is as already explained.
The second leg 220 is connected to the load 30 as a self-supporting leg. This is also as already explained.
The third leg 230 and the fourth leg 240 are connected to the storage battery 35 as designated power transmission / reception legs. This is also as already explained.

  The fifth leg 250 is an AC through leg. The AC through leg 250 is connected to the designated power transmission / reception leg of the other power router 300, and the AC through leg 250 is connected to the storage battery 35 via the connection terminal 245 of the fourth leg 240. Since the AC through leg 250 does not have a power conversion unit, this connection relationship is equivalent to that the designated power transmission / reception leg of the other power router 300 is directly connected to the storage battery 35. It will be appreciated that such a connection is allowed.

The sixth leg 260 is connected to the backbone system 11 as a designated power transmission / reception leg. It will be understood that such a connection is allowed if the predetermined power is received from the backbone system 11 via the sixth leg 260.
In addition, in relation to the fact that the first leg 210 is a master leg, the master leg 210 is necessary from the backbone system 11 if the power received by the sixth leg 260 is not sufficient to maintain the rating of the DC bus 201. Power will be received. On the contrary, when the power received by the sixth leg 260 exceeds the amount necessary for maintaining the rating of the DC bus 201, the master leg 210 releases excess power to the backbone system 11.

  Next, a case where power routers are connected will be described. Connecting power routers means connecting a leg of one power router and a leg of another power router. When the legs are connected, there are restrictions on the operation modes that can be combined.

  The combinations of connections shown in FIGS. 4 and 5 are examples of possible combinations. In FIG. 4, the master leg 110 of the first power router 100 and the self-supporting leg 210 of the second power router 200 are connected. Although not described in detail, it is assumed that the master leg 220 of the second power router 200 is connected to the backbone system 11 and thereby the voltage of the DC bus 201 of the second power router 200 is maintained at a rating.

  In FIG. 4, when power is supplied from the first power router 100 to the load 30, the voltage of the DC bus 101 decreases. The master leg 110 procures power from the connection partner so as to maintain the voltage of the DC bus 101. That is, the master leg 110 draws the insufficient power from the independent leg 210 of the second power router 200. The independent leg 210 of the second power router 200 sends out the power required by the connection partner (here, the master leg 110). In the DC bus 201 of the second power router 200, the voltage is reduced by the amount of power sent from the self-supporting leg 210, but this is compensated from the backbone system 11 by the master leg 220. In this manner, the first power router 100 allows the necessary power to be accommodated from the second power router 200.

  As described above, even if the master leg 110 of the first power router 100 and the self-supporting leg 210 of the second power router 200 are connected, the roles of the master leg 110 and the self-supporting leg 210 are matched. There is no inconvenience. Therefore, it can be seen that the master leg and the independent leg may be connected as shown in FIG.

  In FIG. 5, the designated power transmission / reception leg 310 of the third power router 300 and the self-supporting leg 410 of the fourth power router 400 are connected. Although not described in detail, the master leg 320 of the third power router 300 and the master leg 420 of the fourth power router 400 are each connected to the backbone system 11, and thus the third power router 300 and the fourth power router 400 are connected to each other. Each DC bus 301, 401 is assumed to maintain a rated voltage.

  Here, it is assumed that the designated power transmission / reception leg 310 of the third power router 300 is instructed to receive the designated power by an instruction from the management server 50. The designated power transmission / reception leg 310 draws the designated power from the self-supporting leg 410 of the fourth power router 400. The self-supporting leg 410 of the fourth power router 400 transmits the power required by the connection partner (here, the designated power transmission / reception leg 310). On the DC bus 401 of the fourth power router 400, the voltage drops by the amount of power sent from the self-supporting leg 410, but this is compensated from the backbone system 11 by the master leg 420.

  As described above, even if the designated power transmission / reception leg 310 of the third power router 300 and the independent leg 410 of the fourth power router 400 are connected, the roles of the designated power transmission / reception leg 310 and the independent leg 410 are matched. There is no inconvenience in either operation. Therefore, it is understood that the designated power transmission / reception leg and the independent leg may be connected as shown in FIG.

  The case where the third power router 300 has the power exchanged from the fourth power router 400 has been described as an example, but conversely, the case where the power is exchanged from the third power router 300 toward the fourth power router 400. But it will be understood that there are no inconveniences as well.

  In this way, the designated power can be interchanged between the third power router 300 and the fourth power router 400.

When the legs having the power conversion unit are directly connected, only the two patterns shown in FIGS. 4 and 5 are allowed.
That is, only the case where the master leg and the independent leg are connected and the case where the designated power transmission / reception leg and the independent leg are connected are allowed.

Next, combinations that cannot be connected to each other are listed.
6 to 9 are patterns that should not be connected to each other.
As can be seen from FIG. 6, FIG. 7, and FIG. 8, legs in the same operation mode must not be connected to each other.
For example, in the case of FIG. 6, the master legs 510 and 610 are connected to each other.
As described above in the description of the driving operation, the master leg first performs a process of generating power synchronized with the voltage, frequency, and phase of the connection partner.
Here, if the connection partner is also a master leg, they try to synchronize with each other's voltage and frequency, but since the master leg does not establish voltage and frequency autonomously, such synchronization processing cannot succeed. .
Therefore, the master legs cannot be connected to each other.
There are also the following reasons.
The master leg must draw power from the connection partner to maintain the voltage on the DC bus. (Alternatively, in order to maintain the voltage of the DC bus, excess power must be released to the connection partner.) If the master legs are connected to each other, they cannot meet the requirements of the connection partner. (If the master legs are connected to each other, both power routers will not be able to maintain the voltage of the DC bus. Then, problems such as power outages may occur in each power cell.) The master legs must collide with each other (because they do not match), so the master legs should not be connected.

In FIG. 7, the designated power transmission / reception legs are connected to each other, but it will be understood that this also does not hold.
Although it is the same as the master leg, as described above in the description of the driving operation, the designated power transmission / reception leg also first performs processing for generating power synchronized with the voltage, frequency, and phase of the connection partner.
Here, if the connection partner is also the designated power transmission / reception leg, they will try to synchronize with each other's voltage and frequency, but the specified power transmission / reception leg does not establish voltage and frequency autonomously. Processing cannot be successful.
Therefore, the designated power transmission / reception legs cannot be connected to each other.
There are also the following reasons.
Even if the designated transmission power to be transmitted by one designated power transmission / reception leg 510 and the designated reception power to be received by the other designated power transmission / reception leg 610 are matched, such designated power transmission / reception is performed. Do not connect the legs together. For example, it is assumed that one designated power transmission / reception leg 510 adjusts the power conversion unit so as to transmit the designated transmission power. (For example, the output voltage is set higher than the connection partner by a predetermined value.) On the other hand, the other designated power transmission / reception leg 610 adjusts the power conversion unit so as to receive the designated received power. (For example, the output voltage is set to be lower than the connection partner by a predetermined value.) At the same time, if such an adjustment operation is performed in both of the designated power transmission / reception legs 510 and 610, they will be out of control. It will be understood that

In FIG. 8, the independent legs are connected to each other, but such a connection should not be made.
A self-supporting leg creates its own voltage and frequency.
If any of the voltage, frequency, and phase generated by the two independent legs are slightly separated while the independent legs are connected to each other, unintended power flows between the two independent legs.
It is impossible to keep the voltage, frequency, and phase produced by the two free standing legs perfectly matched, so the free standing legs cannot be connected together.

In FIG. 9, the master leg and the designated power transmission / reception leg are connected.
It will be understood from the above explanation that this also does not hold. Even if the master leg 510 attempts to transmit / receive power to the connection partner so as to maintain the voltage of the DC bus 501, the designated power transmission / reception leg 610 does not transmit / receive power according to the request of the master leg 510. Therefore, the master leg 510 cannot maintain the voltage of the DC bus 501. Further, even if the designated power transmission / reception leg 610 attempts to send / receive the designated power to / from the connection partner (510), the master leg 510 does not transmit / receive power in response to a request from the designated power transmission / reception leg 610. Therefore, the designated power transmission / reception leg 610 cannot transmit / receive the designated power to / from the connection partner (here, the master leg 510).

  Up to this point, the case where the legs having the power conversion units are connected to each other has been considered. However, when the AC through leg is taken into consideration, the patterns of FIGS. 10 to 13 are also possible. The AC through leg is simply a bypass because it does not have a power converter. Therefore, as shown in FIGS. 10 and 13, the master leg 110 of the first power router 100 is connected to the backbone system 11 via the AC through leg 250 of the second power router 200. The master leg 110 is connected to the backbone system 11. It is essentially the same as being directly connected. Similarly, as shown in FIGS. 12 and 13, the designated power transmission / reception leg 110 of the first power router 100 is connected to the backbone system 11 via the AC through leg 250 of the second power router 200. This is essentially the same as that the power receiving leg 110 is directly connected to the backbone system 11.

Nevertheless, it is convenient to have AC through. For example, as shown in FIG. 14, the distance from the first power router 100 to the backbone system 11 is very long, and in order to connect the first power router 100 to the backbone system 11, it passes through several power routers 200 and 300. There are cases where it is necessary to do this.
If there is no AC through leg, as shown in FIG. 4, it is necessary to go through one or more independent legs. When going through a leg having a power conversion unit, it goes through conversion from AC power to DC power and from DC power to AC power. Although power loss still occurs in power conversion even if it is only a few percent, it is inefficient to require multiple times of power conversion just to connect to the backbone system.
Therefore, it is meaningful to provide an AC through leg without a power conversion unit in the power router.

  What has been described so far is summarized in FIG. FIG. 16 shows an example in which four power routers 100-400 are connected to each other. Since any connection relation has appeared in the above description, each connection destination will not be described in detail, but it will be understood that both are permissible connection relations.

Here, it supplements about the connection line which connects an electric power router and a connection other party.
If a connection line connecting the power routers is referred to as a power transmission line, the power transmission line may be a part of the backbone system or may be disconnected from the backbone system.
(In FIG. 16, a power transmission line 71A is attached to a power transmission line that is a part of the backbone system, and a power transmission line 71B is attached to a power transmission line that is cut off from the backbone system.)
That is, a plurality of power routers may be connected to the backbone system. By connecting two or more power routers via the backbone system in this way, it becomes possible to accommodate power between the plurality of power routers via the backbone system, and to compensate for excess or deficiency of the interchanged power in the backbone system. You can also. On the other hand, two or more power routers may be connected without going through the backbone system.
Further, if the connection line connecting the power router and the load (or distributed power source) is referred to as a distribution line 72, the distribution line 72 is disconnected from the backbone system 11. That is, the distribution line 72 that connects the power router and the load (or distributed power source) is not connected to the backbone system 11.

Further, as illustrated in FIG. 17, the power routers 100 to 400 may be connected in a bus connection.
The description of the operation mode of each leg is omitted, but it is a matter of course that the operation mode of each leg must be appropriately selected in consideration of the direction of power interchange and the connection constraints described so far.
In FIG. 17, it goes without saying that the backbone system 11 may be replaced with a distributed power source such as a storage battery or a power generation facility. That is, a plurality of power routers may be bus-connected to the distributed power source.

The example shown in FIG. 18 is an example of a connection form in which two power routers 100 and 200 are connected to the backbone system 11.
In FIG. 18, the backbone system 11 may be replaced with a distributed power source.

  As described so far, the power router connection partner includes a main system, a distributed power source including a storage battery and a power generation facility, and other power routers. It is called a power system.

  With the power router, a power network system in which power cells are asynchronously interconnected can be constructed. Then, by following the connection restrictions described in this embodiment, the legs can be connected so that their roles do not contradict each other. Thereby, the power network system can be expanded and the whole can be stably operated.

  As described above, the master leg plays a role of maintaining the DC bus voltage at a constant voltage. If the master leg breaks down or the connection destination of the master leg is hit by a failure such as a power failure, the DC bus voltage is not maintained. If all master legs in one power router stop functioning, the DC bus voltage rises or falls due to the power flowing into or out of the DC bus through the other legs, affecting the operation of the power router. Effect. Therefore, it is important to select one or more master legs with one power router, and when the master leg stops, it is important to switch the operation mode of other legs to the master mode. As described above, since the master leg plays an important role, the connection destination of the master leg is also required to have stability and reliability. Therefore, it is very important from the viewpoint of stability of the power router to determine a guideline for selecting a leg to be operated in the master mode from a plurality of legs in the power router.

  Therefore, the following embodiments of the present invention provide a guideline for selecting a leg to be operated in the master mode from a plurality of legs in the power router.

<Embodiment 1 of the Invention>
FIG. 19 is a block diagram showing a configuration of a power network system 10a including the power router 100a and the management server 52 according to the first embodiment of the present invention. The schematic configuration of the power network system 10a according to the first embodiment of the present invention is the same as that shown in FIG. Accordingly, FIG. 19 mainly illustrates the portion related to the first embodiment of the present invention.

  The power network system 10a includes at least a power router 100a, a management server 52, a backbone system 11, a power router 200a, a load 30, a storage battery 35a, and a storage battery 35b. The backbone system 11, the load 30, the storage battery 35a, and the storage battery 35b are the same as those described above. However, the storage battery 35a is managed by the management server 52, and the storage battery 35b is managed by the power router 100a. Moreover, the connection destination of the power router 100a in FIG. 19 is an example, and is not limited thereto.

  The power routers 100a and 200a belong to different power cells (not shown), and asynchronously connect the power cells to which they belong to an external power system. Hereinafter, the configuration and function of the power router 100a will be described. Since the power router 200a has the same configuration and function as the power router 100a, its illustration and description are omitted. The power router 100a includes at least a DC bus 101, legs A to E, and a control unit 190a. The other configuration of the power router 100a and the internal configuration of the legs A to E are the same as those in FIGS. 1 and 2 described above, and thus illustration and description thereof are omitted.

  In FIG. 19, the external connection terminal of Leg A is connected to the backbone system 11, the external connection terminal of Leg B is connected to the power router 200a, the external connection terminal of Leg C is connected to the load 30, and the external connection of Leg D The terminal is connected to the storage battery 35a, and the external connection terminal of the leg E is connected to the storage battery 35b.

  The controller 190a controls the legs A to E so that each of the legs A to E operates in a predetermined operation mode. The predetermined operation mode is preferably, for example, any one of the above-described master mode, independent mode, and designated power transmission / reception mode. The controller 190a sets at least one operation mode of the legs A to E to the master mode. The control unit 190a also has the function of the control unit 190 of FIG.

  The control unit 190a associates one index value with each of the legs A to E. The index value is a value indicating the possibility that the corresponding leg is selected as the master leg. For example, it is expressed numerically. It can be said that the index value indicates whether or not the corresponding leg is suitable as the master leg. However, the index value is not necessarily binary.

  The controller 190a may set a fixed index value for each leg. Further, the index value may be determined periodically or at an arbitrary timing. Furthermore, the index value may be determined when the master leg is selected. The control unit 190a may update the index value every time the state of the power router, the leg, or the connection destination of the leg changes. The control unit 190a desirably determines the index value based on at least one of the current state, the past state history, and the future state prediction at the power router, the leg, or the connection destination of the leg. For example, a leg connected to a system that has caused failures many times in the past is not suitable as a master leg because of poor reliability. The control unit 190a determines the index value of the leg so that the possibility that the leg is selected as the master leg is low. The control unit 190a determines the index value of each leg in consideration of the type of connection destination of each leg. For example, if a connection destination of a certain leg is a backbone system, a power generation device, or a power storage device, the leg can be a master leg. Furthermore, if the connection destination of a leg is a backbone system, it can be said that the leg is more suitable as a master leg than when the connection destination is a storage battery. In addition, if the connection destination of one leg is the other leg of another power router and the operation mode of the other leg is not a self-supporting mode, the one leg is connected to the master leg due to the connection restriction between the legs. Should not be. Further, the control unit 190a may set an index value based on the hardware specifications of each leg. For example, the control unit 190a may set the index value based on the rated output value that is the maximum output value of the voltage of each leg. In this case, the larger the rated output value, the better the master leg. Further, the control unit 190a may set an index value based on the current operation state of each leg, for example, depending on the operation mode, operation, or stop. For example, if the leg is stopped, the control unit 190a can be said to be the next master leg. Further, when switching the master leg, it can be said that the leg whose operation mode is already the master mode is not subject to switching.

  When the master leg fails or the connection destination of the master leg fails, the control unit 190a selects a new master leg from the legs A to E excluding the fault leg. At this time, the control unit 190a refers to the index value of the candidate leg, selects the most suitable leg as the master leg, and controls the operation with the leg as the master leg. By selecting a leg in the power router in this way, the master leg can be quickly switched when a failure occurs, and the operation of the power router can be continued.

  The management server 52 is connected to a power cell having the power router 100a and a power cell having the power router 200a via a network (not shown). The management server 52 is an information processing apparatus that manages the power routers 100a and 200a. Here, instead of the power router 100a, the management server 52 may select at least one leg to be operated and controlled as the master mode from the legs A to E based on the index value associated with each leg. . In this case, the management server 52 instructs the power router 100a to perform operation control using the selected leg as the master mode.

  The management server 52 replaces the control unit 190a with at least the type of connection destination of each leg, or at least the current state, the past state history, or the prediction of the future state at the power router, leg or leg connection destination. The index value may be determined based on either of them.

  FIG. 20 is a block diagram showing a configuration of the management server 52 according to the first embodiment of the present invention. The management server 52 includes a CPU (Central Processing Unit) 521, a memory 522, a communication unit 523, and a hard disk 524.

  The hard disk 524 is a non-volatile storage device. The hard disk 524 stores an OS (not shown) and an operation program 525. Here, the operation program 525 is a computer program in which an operation process (for example, the process of FIG. 21 described later) of the power router according to the first embodiment of the present invention is implemented.

  The CPU 521 controls various processes in the management server 52, access to the memory 522, the communication unit 523, the hard disk 524, and the like. The communication unit 523 performs communication with the outside including the power routers 100a and 200a.

  In the management server 52, the CPU 521 reads and executes the OS, the operation program 525, and the like stored in the memory 522 or the hard disk 524. Thereby, the management server 52 can implement | achieve the driving | operation process of an electric power router.

  Note that a configuration corresponding to FIG. 20 may be provided in a part of the power router 100a, and the control unit 190a may execute the operation program 525.

  FIG. 21 is a flowchart showing a flow of operation processing of the power router according to the first exemplary embodiment of the present invention. First, the control unit 190a determines an index value for each leg (S11). That is, the control unit 190a determines the index value based on at least one of the current state, the past state history, and the future state prediction at the power router, the leg, or the connection destination of the leg. The index value of each leg is held in a memory (not shown) built in the power router.

  Subsequently, the control unit 190a refers to the index value of each leg and selects at least one leg to be operated in the master mode from the legs A to E (S12). For example, when the index value is larger, the control unit 190a selects the leg having the largest index value when it is suitable as the master leg.

  Thereafter, the control unit 190a performs operation control using the selected leg as a master leg (S13). When the management server 52 executes step S13, the control unit 190a executes step S14 in response to an instruction from the management server 52.

<Embodiment 2 of the Invention>
The second embodiment of the present invention is a modification of the first embodiment described above. Hereinafter, the index value of the first embodiment is referred to as priority. FIG. 22 is a block diagram showing a configuration of a power network system 10b including the power router 100b and the management server 52a according to the second embodiment of the present invention. The difference between the power router 100b and the power router 100a is that the power router 100b includes a control unit 190b instead of the control unit 190a, and further includes a storage unit 180.

  The storage unit 180 is a storage device that stores the priority table 181. The priority table 181 is a table in which the identifier of each leg in the power router 100b is associated with the priority of the leg. There are two priorities for each leg, the first priority is the priority p1 determined by the control unit 190b, and the second priority is the priority p2 determined by the management server 52a. . The management server 52a notifies the power router 100b of the priority determined for each leg, and stores it in the area for the management server 52a in the priority table 181 as the priority p2. When priority p1 and priority p2 are not particularly distinguished, they are described as priority.

  The reason why two priorities are provided for each leg is because the types of information that can be directly grasped by the power router 100b and the management server 52a are different. For example, the power router 100b can directly detect the failure of the power router itself, the legs included in the power router, and the connection destination of these legs. However, the management server 52a cannot directly detect these failures. On the other hand, the management server 52a can detect the wide area information such as the failure occurring ahead of the connection destination of the leg of the power router 100b and the presence or absence of the planned power outage more quickly than the power router 100b.

  Basically, the higher the priority value of a leg, the higher the possibility that the leg will be selected as the master leg. However, when a specific priority value is set to a leg, the control unit 190b does not select the leg as a master leg. A priority value for excluding a leg from a master leg candidate is called an exclusion value. Note that the number of excluded values is not necessarily one.

  In addition to the function of the control unit 190a, the control unit 190b has a function of assigning a priority p1 equal to the exclusion value to a leg that is determined not to be selected as a master leg. A leg that should not be selected as a master leg is a leg that cannot maintain the DC bus voltage at a constant voltage, or a leg that is expected to be unable to be maintained in the future. For example, since the failed leg cannot maintain the DC bus voltage, the control unit 190b assigns the priority p1 of the exclusion value to the leg, and prevents the leg that cannot serve as the master leg from becoming the master leg.

  In addition to the function of the management server 52, the management server 52a has a function of assigning a priority p2 equal to the exclusion value to a leg that is determined not to be selected as a master leg.

  The storage unit 180 may be arranged in the management server 52a. In this case, the control unit 190b notifies the priority determined for each leg to the management server 52a, and stores it in the area for the control unit 190b (power router 100b) in the priority table 181 as the priority p2. However, since the physical distance between the control unit 190b and the priority table 181 is shorter when the storage unit 180 is arranged in the power router 100b than in the management server 52a, the master leg is switched. Becomes faster.

  When the priority of the leg cannot be determined by its own judgment, the power router 100b assigns the priority p1 equal to the minimum value to the leg. Similarly, when the priority of a leg cannot be determined by its own judgment, the management server 52a assigns a priority p2 equal to the minimum value to that leg. Here, the minimum value is a lower limit of a range of values that can be used as priority values. If either leg priority p1 or priority p2 is equal to the minimum value, the other priority is the final priority of the leg. If both leg priority p1 and priority p2 are equal to the minimum, the leg is excluded from the master leg candidates. That is, the minimum value is also one of exclusion values.

  Take the example of assigning a minimum priority to a leg. The storage battery 35a connected to the leg D in FIG. 22 is under the jurisdiction of the management server 52a. Therefore, the power router 100b cannot directly acquire information (remaining capacity, etc.) regarding the storage battery 35a, and cannot determine whether the leg D can be selected as a master leg. In this case, the control unit 190b of the power router 100b sets the priority p1 of the leg D to the minimum value. On the other hand, the storage battery 35b connected to the leg E is under the jurisdiction of the power router 100b. In this case, conversely, the management server 52a sets the priority p2 of the leg E to the minimum value.

  Hereinafter, a method in which the control unit 190b or the management server 52a determines the priority will be described.

  The control unit 190b or the management server 52a determines the priority based on the type of the connection destination of the leg. If the connection destination of a leg is a load, a master leg, or a designated power transmission / reception leg, that leg cannot be a master leg, and the priority of that leg is set as an exclusion value. If the connection destination of the leg is a backbone system, a power generation device, a power storage device, or a self-supporting leg, the leg can be a master leg, and priority other than the exclusion value is set for the leg.

  The control unit 190b or the management server 52a determines the priority based on the presence or absence of a failure in the leg or its connection destination. If there is a fault, the leg should not be driven, so the priority of the leg is set to the exclusion value.

  The control unit 190b or the management server 52a determines the priority based on the probability that the leg or its connection destination will stop in the future. The higher the probability, the lower priority may be assigned to the leg. In particular, when it is clear that a leg or its connection destination will stop in the near future, the priority of the leg is set as an exclusion value. Such cases include power shortages or planned power outages due to maintenance.

  The control unit 190b or the management server 52a determines the priority based on the power transmission / reception capability and stability of the leg and its connection destination, and the power transmission line connecting the leg and the connection destination. This power transmission / reception capability includes the transmission capacity of the transmission line. If their power transmission / reception capability and stability are sufficiently high, the voltage of the DC bus 101 of the power router 100b is kept stable. Therefore, a higher priority may be assigned to the leg as the power transmission / reception capability and stability are higher.

  When the type of the connection destination of the leg is the power storage device, the control unit 190b or the management server 52a determines the priority based on the remaining capacity. If the amount of power that can be discharged from the power storage device is small, the voltage of the DC bus 101 of the power router 100b cannot be sufficiently increased using the discharged power. If the amount of power that can be charged is small, the voltage of the DC bus 101 cannot be lowered sufficiently by transferring power from the DC bus 101 to the power storage device. In other words, in order for the leg to operate in the master mode, the remaining capacity of the power storage device must not be too much or too little. Therefore, when the remaining capacity of the power storage device exceeds a predetermined upper limit value or falls below a predetermined lower limit value, the control unit 190b or the management server 52a sets the priority of the leg as an excluded value. Moreover, you may assign a low priority to the leg, so that the absolute value of the difference of the remaining capacity of an electric power storage apparatus and an ideal amount is large. Here, the ideal amount is desirably half of the full charge capacity of the power storage device.

  When the connection destination of the leg is the power generation device or the power storage device, the control unit 190b or the management server 52a determines the priority based on the management entity of the power generation device or the power storage device. In particular, when the connection destination of a leg is a power generation device or a power storage device managed by the management server 52a, the control unit 190b sets the priority of the leg to the minimum value. In addition, when the connection destination of the leg is a power generation device or a power storage device managed by the power router 100b, the management server 52a sets the priority of the leg to the minimum value.

  When the connection destination of the leg is a power generation device or a power storage device, the control unit 190b or the management server 52a determines the priority based on the power that can be input / output (charge / discharge) by the power generation device or the power storage device. If the input / output (charge / discharge) power is sufficiently high, the voltage of the DC bus 101 of the power router 100b is kept stable. Therefore, a higher priority may be assigned to the leg as the input / output (charge / discharge) power is higher.

  The control unit 190b or the management server 52a determines the priority based on the history of the magnitude of power transmitted and received in the past at the leg or its connection destination. For example, even if the power transmission / reception capability according to the specifications of the leg or its connection destination is high, the leg may not be suitable as a master leg if the performance of power transmitted / received in the past is low. .

  The control unit 190b or the management server 52a determines the priority based on the history of failures that occurred in the past in the leg and its connection destination, and the power transmission line connecting the leg and the connection destination. For example, when a leg is connected to a system that is prone to power failure, it is desirable to lower the priority of the leg. The control unit 190b or the management server 52a can also calculate the frequency of failure of the connection destination by acquiring the history from the connection destination of the leg, and analyzing and processing the history. The higher the frequency, the lower priority may be assigned to the leg.

  The control unit 190b or the management server 52a determines the priority based on the charge of power transmitted and received between the leg and the connection destination. This fee includes the consignment fee for the transmission line connecting the leg and the connection destination. Charges may vary from supply to supply due to liberalization of electricity. Also, the charge may vary depending on the time of day. Thus, the lower the fee, the higher priority may be assigned to that leg.

  Although the priority determination method has been described above, the method is not limited to the above.

  Hereinafter, a method in which the control unit 190b selects the most suitable leg as the master leg with reference to the priority table 181 will be described.

  As described above, the priority table 181 has the priority p1 and the priority p2 for each leg of the power router 100b. The control unit 190b obtains the final priority p3 for each leg. The final priority p3 of a leg is the larger of the priority p1 and the priority p2 of the leg. At this time, the exclusion value and the minimum value are not treated specially, and the comparison is made purely numerically.

  Note that the method of determining the final priority p3 is not limited to this. The final priority p3 is an output of some function that receives the priority p1 and the priority p2. For example, the control unit 190b may set the sum of the priority p1 and the priority p2 as the final priority p3. Further, when either the priority p1 or the priority p2 is equal to the exclusion value, the final priority p3 may be forcibly set as the exclusion value.

  Thereafter, the control unit 190b selects a leg having the highest final priority p3 among the final priorities p3 of all the legs of the power router 100b as the master leg. At this time, the leg having the final priority p3 equal to the exclusion value is excluded from the selection candidates. In other words, the control unit 190b selects, as the master leg, the leg having the maximum final priority p3 among all the legs having the final priority p3 not equal to the excluded value.

The method for selecting the master leg by the control unit 190b has been described above, but the management server 52a can also select the master leg by the same method.

  FIG. 23 is a diagram showing an example of the priority table 181 according to the second embodiment of the present invention. The priority table 181 has areas for storing the leg identifiers (A to E), the priority p1 determined by the power router 100b, and the priority p2 determined by the management server 52a for each leg. For leg A, the control unit 190b of the power router 100b assigns priority p1 "60", and the management server 52a assigns priority p2 "90".

  The control unit 190b compares the priority p1 "60" of the leg A with the priority p2 "90", and sets the priority p2 "90", which is a larger value, as the final priority p3 of the leg A. Similarly, the control unit 190b obtains the final priority p3 for the legs B to E. Thereafter, the control unit 190b selects the leg A having the maximum final priority p3 “90” among the final priorities p3 of the legs A to E as the master leg.

  The final priority p3 only needs to be obtained by the time when the master leg should be selected. The control unit 190b may obtain all the final priorities p3 when selecting the master leg. The control unit 190b may recalculate the corresponding final priority p3 each time the priority p1 or the priority p2 in the priority table 181 is updated. In this case, the control unit 190b may add an area for storing the final priority p3 to the priority table 181 and store the recalculated final priority p3 in the area.

  FIG. 24 is a diagram illustrating an example of the priority table 181 including an exclusion value according to the second embodiment of the present invention. Here, the priority range is from 0 to 100, the exclusion values are 0 and 100, and the minimum value is 0. As described above, the minimum value is also an exclusion value. In this example, the maximum priority value is equal to the exclusion value, but the present invention is not limited to this.

  The control unit 190b compares the priority p1 "90" of the leg A with the priority p2 "100", and sets the priority p2 "100", which is a larger value, as the final priority p3 of the leg A. Also, the priority p1 "0" of the leg D is compared with the priority p2 "10", and the higher priority p2 "10" is set as the final priority p3 of the leg D. Here, the priority p2 “100” of the leg A and the priority p1 “0” of the leg D are both excluded values, but these comparisons do not consider whether the priority p1 or the priority p2 is an excluded value. . Similarly, the control unit 190b obtains the final priority p3 for the legs B, C, and E.

  The final priority p3 of leg A and the final priority p3 of leg C are both 100, that is, equal to the exclusion value. The final priority p3 of the other legs is not equal to the excluded value. Therefore, the control unit 190b excludes the leg A and the leg C from the selection candidates, and selects the leg B having the largest final priority p3 “70” among the final priorities p3 of the legs B, D, and E as the master. Select as a leg.

  The priority relationship may be reversed. Further, the priority range and the exclusion value are not limited to the above example. Furthermore, the priority may be other than a numerical value as long as the order relation of values is determined. For example, the priority may be a symbol such as A, B, or C.

<Third Embodiment of the Invention>
The third embodiment of the present invention relates to an update opportunity of the priority table 181 and a master leg switching opportunity in the above-described second embodiment.

The control unit 190b must start maintaining the voltage of the DC bus 101 when the power router 100b is activated. Therefore, the control unit 190b selects at least one leg that is most suitable as a master leg with reference to the priority table 181 and controls the operation of the selected leg in the master mode. Therefore, when the power router 100b is activated, the contents of the priority table 181 must be initialized by some method.
Hereinafter, three methods (A), (B), and (C) will be exemplified as methods for initializing the contents of the priority table 181 when the power router 100b is activated. A plurality of (A) to (C) may be combined.

(A) Method by which the operator or installer of the power router determines the contents of the priority table 181 The operator or installer of the power router 100b determines the initial value of the priority for each leg included in the power router 100b in advance. The initial value is recorded in the corresponding priority p1 in the priority table 181. Also, all priorities p2 in the priority table 181 are set to 0. For example, referring to FIG. 22, since the connection destination of leg A is the backbone system 11, leg A is suitable as a master leg. Therefore, the operator or installer of the power router 100b sets a value other than the excluded value for the priority p1 of the leg A in the priority table 181. FIG. 25 is a diagram illustrating an example of initial values of the priority table according to the third embodiment of the present invention.

(B) Method by which the control unit 190b determines the contents of the priority table 181 based on the remaining capacity of the power storage device managed by the power router 100b The control unit 190b is managed by the power router 100b when the power router 100b is activated. Obtain the remaining capacity of the power storage device. When the remaining capacity exceeds a predetermined upper limit value or falls below a predetermined lower limit value, the control unit 190b sets the leg priority p1 in the priority table 181 as an exclusion value. This leg is a leg connected to the power storage device. In addition, the control unit 190b may set the priority p1 to a value that decreases as the absolute value of the difference between the remaining capacity and the ideal amount increases. Here, the ideal amount is desirably half of the full charge capacity of the power storage device.

(C) Method by which the management server 52a determines the contents of the priority table 181 The management server 52a obtains an initial value of priority in advance for each leg included in the power router 100b. For example, referring to FIG. 22, the power storage device 35a connected to the leg D is under the jurisdiction of the management server 52a. Therefore, the management server 52a determines the initial value of the priority of the leg D based on the remaining capacity of the power storage device 35a (this determination method is as described in (B) above). When the power router 100b is activated, the control unit 190b accesses the management server 52a, acquires initial values of priorities determined by the management server 52a, and uses those initial values as priority levels of corresponding legs in the priority table 181. Record at p2.

  A method for updating the priority table 181 during operation of the power router 100b will be described. FIG. 26 is a flowchart showing the flow of priority update processing according to the third embodiment of the present invention. First, the control unit 190b monitors whether or not the state of each leg and its connection destination in the power router 100b to which the control unit 190b belongs has changed (S21). The change in state includes a decrease in output of the power generation device or power storage device to be connected, and a change in the remaining capacity of the power storage device. Further, the change in state includes that the control unit 190b detects a future stoppage or operation schedule of each leg or its connection destination. Furthermore, the state change includes that the control unit 190b acquires the past history regarding the operating state and power transmission / reception of each leg or its connection destination.

  Next, the control unit 190b determines whether or not a change in the state of the leg or the connection destination is detected (S22). If not detected, the process returns to step S21. If the state change is detected, the control unit 190b determines at least the priority of the leg in which the state change is detected (S23). Thereafter, the control unit 190b updates the priority p1 corresponding to the corresponding leg in the priority table 181 stored in the storage unit 180 to the priority determined in step S23 (S24).

  Note that the management server 52a may perform the update process of FIG. In this case, the management server 52a updates the priority p2 instead of the priority p1 in step S24. Further, both the control unit 190b and the management server 52a may perform the update process of FIG. 26 in parallel. Furthermore, the control unit 190b or the management server 52a may update the priority table 181 at predetermined intervals instead of FIG.

  FIG. 27 is a flowchart showing the flow of the master leg switching process according to the third embodiment of the present invention. First, the control unit 190b determines whether or not it is a switching opportunity (S31). Here, the trigger for switching is, for example, when the priority table 181 is updated, when a predetermined interval has arrived, or when the administrator of the management server 52a or the power router 100b instructs switching. It is. If it is not an opportunity for switching, step S31 is repeated. Based on the priority table 181 stored in the storage unit 180, the control unit 190b selects a leg whose operation is controlled in the master mode (S32). This selection is performed according to the method described in the second embodiment of the present invention.

  The control unit 190b determines whether or not the current master leg is different from the leg selected in step S32 (S33). If both are the same, it is not necessary to switch the master leg, and the switching process is terminated. On the other hand, if the two are different, the control unit 190b switches the master leg (S34). That is, the control unit 190b sets the operation mode of the leg selected in step S32 to the master mode, and sets the operation mode of the leg that has been the master leg so far to an operation mode other than the master mode.

  When the management server 52a performs the above switching process, the management server 52a sends an instruction to the power router 100b to set the operation mode of the leg selected in step S32 to the master mode instead of step S34. I do. Moreover, the process which sends the instruction | indication which sets the operation mode of the leg which was a master leg until now to operation modes other than master mode to the electric power router 100b is also performed.

<Embodiment 4 of the Invention>
The fourth embodiment of the present invention is an application of the above-described second embodiment. Here, the priority value range that can be specified by the power router and the priority value range that can be specified by the management server do not overlap. However, it is assumed that an exception value (including a minimum value) can be specified in common for both the power router and the management server. By doing so, it is possible to prevent the priority values from competing between the power router and the management server, and each can determine the priority without depending on the other.

  FIG. 28 is a diagram showing an example of priority assignment according to the fourth exemplary embodiment of the present invention. Here, the power router uses values belonging to the High area (200 to 299) and the Low area (1 to 99) as priorities, and the management server uses the intermediate area (100 to 199) as priorities. Further, both the power router and the management server use the exclusion values (0 and 300). In this case, for a certain leg, if the power router sets the value belonging to the High area as the priority, the management server will ignore the intention of the management server, regardless of the value set to the priority by the management server. Is reflected.

  The power router may set a value belonging to the High area as a priority for a leg whose connection destination is a power storage device under the power router. By doing so, the priority of the leg connected to the power storage device under the power router can be made higher than the priority of the leg connected to the power storage device under the management server. Note that the power router may select a value belonging to the High region based on the remaining capacity of the power storage device.

  The management server sets a value belonging to the intermediate area as a priority for a leg whose connection destination is a power storage device under the management server. At this time, the management server may select a value belonging to the intermediate area based on the remaining capacity of the power storage device. Further, the management server sets a value belonging to the intermediate area as a priority for a leg whose connection destination is a backbone system or another power router. At this time, the management server may select a value belonging to the intermediate area based on the power transmission / reception capability and stability of the connection destination of the leg.

  The power router may set a value belonging to the Low area as a priority for a leg whose connection destination is a power storage device under the power router. By doing so, the priority of the leg connected to the power storage device under the power router can be made lower than the priority of the leg connected to the power storage device under the management server. The power router may select a value belonging to the Low area based on the remaining capacity of the power storage device.

  When the power router or the management server detects a failure of the power router or the leg, the power router or the management server sets the exclusion value “300” as the priority of the leg. If the power router or the management server cannot determine whether or not a certain leg can be made a master leg, the priority of the leg is set to the minimum value “0” and the determination is delegated to the other.

  Note that the method of allocating the area is not limited to this. The size of each region may not be uniform. Further, it is not necessary to allocate the management server area between the power router value ranges. Two areas may be allocated to the management server, and an area of the power router may be allocated between them. Further, the number of regions is not limited to this. The value range need not be 0 to 300, and the step size of the priority may not be one unit.

  FIG. 29 is a diagram showing another example of priority assignment according to the fourth exemplary embodiment of the present invention. Here, the power router uses values belonging to the High region (400 to 499), the Middle region (200 to 299), and the Low region (1 to 99) as the priority, and the management server uses the High region (300 to 399). A value belonging to the Low region (100 to 199) is used as the priority. Further, both the power router and the management server use exclusion values (0 and 500). In FIG. 29, the area is divided more finely than in FIG.

  FIG. 30 is a diagram showing an example of a priority table according to the fourth embodiment of the present invention. This priority table is based on the priority assignment of FIG. The controller 190b selects a master leg with reference to this priority table according to the method described in the second embodiment of the present invention. The control unit 190b determines the final priority p3 from the priority p1 and the priority p2 for each of the legs A to E. Since the final priority p3 of the leg A and the leg C is equal to the exclusion value “500”, the control unit 190b excludes the leg A and the leg C from the master leg candidates. The control unit 190b selects the leg B having the highest final priority p3 "370" among the remaining legs as the master leg.

  The control unit or the like of the power router according to the first to fourth embodiments described above may select a plurality of legs for operation control in the master mode. For example, the control unit or the like selects N legs in descending order of priority in the priority table and controls the operation of these legs in the master mode.

<Embodiment 5 of the Invention>
The fifth embodiment of the present invention is a modification of the first embodiment described above. In particular, the case where the master leg cannot maintain the voltage of the DC bus at a predetermined rated voltage or the case where the maintenance is expected to be impossible in the future is targeted. Then, a method of selecting a new master leg candidate when these cases are detected as “abnormality related to the master leg” and controlling the operation of the selected leg in the master mode will be described.

  FIG. 31 is a block diagram showing a configuration of a power network system 10c including the power router 100c and the management server 52b according to the fifth embodiment of the present invention. The difference between the power router 100c and the power router 100a is that the power router 100c has a control unit 190c instead of the control unit 190a, and further includes a storage unit 180a.

  The storage unit 180a is a storage device that stores the priority table 181a and the leg information table 182. The priority table 181a is a table in which the identifier (leg ID) of each leg in the power router 100c is associated with the priority of the leg. However, the priority of the leg in the priority table 181a may be at least the index value in the first embodiment. Alternatively, the leg priority in the priority table 181a may be a value corresponding to the final priority p3 in the second embodiment. For example, the priority table 181a may be a table in which an area of the final priority p3 is added to the priority table 181.

  The leg information table 182 is a table in which the leg ID, rated output, current output, and current operation mode of each leg are associated with each other. However, the leg information table 182 may be a table in which at least the leg ID and the rated output are associated with each other.

  Here, the “rated output” of a leg is an example of a power transmission / reception possible power value that is a power value that can be transmitted and received, and is a power value at which the leg can be output (power transmission / reception is possible). The “rated output” of the leg is the hardware specification of the leg. The leg ID and the rated output are values set in advance in the leg information table 182, and are registered in the leg information table 182 at the time of activation of the power router 100c or timing added to the power router 100c, for example.

  The “current output” of a leg is a power value that the leg is currently outputting (transmitting or receiving power). The “current output” of the master leg can be said to be a current power value that is a currently available power value. A “current operation mode” of a leg is an operation mode in which the operation of the leg is currently controlled. The “current output” and “current operation mode” are values that can be dynamically updated during the operation of the power router 100c.

  FIG. 32 is a diagram showing an example of the leg information table 182 according to the fifth embodiment of the present invention. Here, the leg ID “1” operates in the master mode, and the current output is 300 W. In addition, the leg ID “2” operates in the Grid Connect (designated power transmission / reception mode) mode, and indicates that the current output is 200 W. Here, when an abnormality related to the leg ID “1” is detected, the switching candidate legs are the legs “2” to “4”.

  Returning to FIG. 31, the description will be continued. The control unit 190c monitors each leg and updates the “current output” and “current operation mode” in the leg information table 182 as appropriate. When the control unit 190c detects an abnormality related to the master leg, the control unit 190c refers to the priority table 181a and the leg information table 182, and newly controls the operation as the master mode from the legs other than the master leg. One or more legs are selected, and the selected candidate leg is controlled in master mode. At this time, the control unit 190c sets at least the priority of the priority table 181a, the rated output or current output of the leg information table 182 in the master leg, the rated output or current output of the leg information table 182 in a leg other than the master leg. Based on that, select a candidate leg. In other words, when detecting an abnormality related to the master leg, the control unit 190c selects the candidate leg so as to maintain the voltage of the DC bus at a predetermined rated voltage based on the priority.

  In addition, the control part 190c can detect the hardware failure of a leg and the change of transmission / reception electric power by monitoring each leg. In addition, the control unit 190c can detect that the voltage of the DC bus cannot be maintained at a rating using a voltage sensor (not shown).

  When the abnormality related to the master leg is a failure of the master leg, the control unit 190c controls the operation of the selected candidate leg in the master mode and stops the operation of the master leg. On the other hand, when the abnormality related to the master leg is not a failure of the master leg, the control unit 190c controls the operation of the selected candidate leg in the master mode and maintains the operation of the master leg or in another operation mode. Control the operation.

  Furthermore, the control unit 190c can select one or more candidate legs according to the priority from the legs other than the master leg, and the total power transmission / reception possible power value in the selected candidate leg can cover the current power value. In this case, all of the selected candidate legs are controlled in the master mode.

  FIG. 33 is a flowchart showing a flow of operation processing of the power router according to the fifth exemplary embodiment of the present invention. First, the control unit 190c detects an abnormality in the master leg (S101). Here, it is assumed that the abnormality of the master leg is a hardware failure and the master leg needs to be switched.

  Next, the control unit 190c sets the priority p to “1” (S102). Then, the control unit 190c determines whether there is a leg to be selected (S103). Specifically, the control unit 190c refers to the priority table 181a and determines whether there is an unselected leg other than the master leg for which the above-described exclusion value is not set.

If it is determined in step S103 that there is a leg to be selected, the control unit 190c selects a leg with priority p from the priority table 181a (S104). Then, the control unit 190c refers to the leg information table 182, and uses the rated output associated with the selected leg (candidate leg) to calculate the planned output value (designated output) using the following equation (1). (S105). The initial value of the scheduled output value is 0.
Scheduled output value = Scheduled output value + Rated output of selected leg (1)

  Thereafter, the control unit 190c determines whether or not the calculated planned output value is equal to or greater than the current power value (current output) of the current master leg (S106). That is, the control unit 190c determines whether or not the current power value can be covered by the scheduled output value of the candidate leg.

  If it is determined in step S106 that the scheduled output value is less than the current power value, the control unit 190c adds 1 to the priority p (S107). Then, the determination in step S103 is performed again.

  If it is determined in step S106 that the planned output value is greater than or equal to the current power value, the control unit 190c switches the master leg (S108). That is, the control unit 190c controls the operation of the selected candidate leg in the master mode, and stops the operation of the master leg.

  If it is determined in step S103 that there is no leg to be selected, the control unit 190c stops all legs included in the power router 100c (S109). Then, the control unit 190c notifies the administrator or the like of the stop and abnormality (S110).

  In the power router operation process according to the fifth exemplary embodiment of the present invention, the master leg may be switched even if the abnormality of the master leg is not a hardware failure. Specifically, if the master leg can maintain the voltage of the DC bus at a predetermined rated voltage at the present time, but cannot be maintained in the future, a more stable master is preliminarily provided. It is desirable to switch to the leg. For example, there is a case where there is a planned power outage at the connection destination of the master leg.

  On the other hand, in the operation processing of the power router according to the fifth exemplary embodiment of the present invention, when the abnormality of the master leg is not a hardware failure, the master leg may be added. For example, if the master leg abnormality is caused by a change in the operating state of the connection destination of the master leg, a decrease in power transmission / reception capability, etc., the master leg that is newly operated while maintaining the current operation of the master leg Thus, the voltage of the DC bus can be maintained at a predetermined rated voltage.

  In these cases, in step S101 in FIG. 33, the control unit 190c may detect an abnormality related to the master leg. At this time, the power router 100c may receive a notification from the management server 52b or the like. Then, after step S101, the type of detected abnormality can be determined, and thereafter, processing according to the type of abnormality can be performed. For example, when adding instead of switching the master leg, the current output of the current master leg is set as the initial value of the planned output value in step S105. In step S106, the planned output value is the rated voltage of the DC bus. In step S108, the candidate leg may be newly controlled in the master mode without stopping the current master leg.

  FIG. 34 is a diagram showing a concept of leg candidate determination in the case where priority table emphasis is applied to the fifth embodiment of the present invention. Note that this is an example different from FIG. First, the output power of the master leg in which an abnormality is detected is 1 kW, and the leg priority is “2”, “1”, “3” for the leg IDs “1” to “3” to be switched, Assume that the rated output is 1 kW, 500 W, and 500 W. Here, the current output or the rated output of the leg information table 182 can be used as the output power of the master leg in which an abnormality is detected.

  At this time, the control unit 190c first selects the leg ID “2” having the priority p = 1. The rated output becomes the designated output value and the planned output value as they are. Here, since the planned output value 500W is less than the current master leg output value 1 kW, the control unit 190c selects the leg ID “1” with the priority p = 2. Since the rated output of the leg ID “1” is 1 kW, the total value of the scheduled output values exceeds the current master leg output value of 1 kW. Therefore, the control unit 190c uses the leg IDs “1” and “2” as candidate legs, and controls the operation in the master mode. At this time, the failed master leg is also stopped. Thereby, the master leg is switched. In addition, the designated output of the leg ID “1” selected later among the candidate legs is adjusted to 500 W so that the total value of the scheduled output values is matched with the output value 1 kW of the current master leg. Therefore, the total output can be stabilized without changing before and after switching of the master leg.

  Thus, according to the fifth embodiment of the present invention, even when an abnormality related to the master leg occurs, it is possible to appropriately control the operation of a new master leg. Therefore, the power network system can be stably operated.

<Sixth Embodiment of the Invention>
The sixth embodiment of the present invention is a modification of the fifth embodiment. The power router according to the sixth embodiment of the present invention is different from the fifth embodiment described above in that the value of the rated output is emphasized when selecting a candidate leg. Therefore, since the configuration of the power router is the same as that of the fifth embodiment, illustration and description thereof are omitted.

  The control unit 190c of the power router according to the sixth exemplary embodiment of the present invention selects candidate legs from the plurality of power conversion legs other than the master leg in descending order of the power transmission / reception possible power value. Then, the control unit 190c adjusts the power transmission / reception possible power value according to the index value associated with each of the selected candidate legs, and calculates the adjusted power value. Thereafter, the control unit 190c controls the operation of the selected candidate leg in the master mode when the total value of the adjusted power values can cover the current power value.

  FIG. 35 is a flowchart showing a flow of operation processing of the power router according to the sixth exemplary embodiment of the present invention. Below, it demonstrates centering on the difference with FIG. First, the control unit 190c detects an abnormality in the master leg (S201). Next, the control unit 190c determines whether there is a leg to be selected (S202).

  When it is determined in step S202 that there is a leg to be selected, the control unit 190c selects the leg with the maximum rated output among the unselected legs in the leg information table 182 (S203). Then, the control unit 190c refers to the leg information table 182, adjusts the rated output of the selected leg by a coefficient corresponding to the priority p of the selected leg, and calculates an adjusted power value (S204). For example, the coefficient of priority p = 1 is 80%, the coefficient of priority p = 2 is 60%, and the like. A value obtained by multiplying the rated output by a coefficient can be used as the adjusted power value.

Thereafter, the control unit 190c calculates a scheduled output value (designated output) using the adjusted power value for the selected leg (candidate leg) according to the following equation (2) (S205). The initial value of the scheduled output value is 0.
Scheduled output value = Scheduled output value + Selected leg adjustment power value (2)

  Thereafter, the control unit 190c determines whether or not the calculated planned output value is equal to or greater than the current power value (current output) of the current master leg (S206). If it is determined in step S206 that the scheduled output value is less than the current power value, the control unit 190c performs the determination in step S202 again. If it is determined in step S206 that the planned output value is greater than or equal to the current power value, the control unit 190c switches the master leg (S207). If it is determined in step S202 that there is no leg to be selected, the control unit 190c stops all legs included in the power router 100c (S208). Then, the control unit 190c notifies the administrator or the like of the stop and abnormality (S209).

  FIG. 36 is a diagram showing a concept of determining a leg candidate in the case where emphasis is placed on the output power of the leg according to the sixth embodiment of the present invention. Note that the upper part (precondition) in FIG. 36 is the same as FIG.

  At this time, the control unit 190c first selects the leg ID “1” having the maximum rated output of 1 kW. Since the priority p of the selected leg ID “1” is “2”, the control unit 190c calculates the designated output (adjusted power value) 600W by multiplying the rated output 1 kW by the coefficient 60%. (And it becomes the planned output value as it is.)

  Here, since the planned output value 600W is less than the current master leg output value 1 kW, the control unit 190c selects the leg ID “2” having the maximum rated output of 500 W among the unselected legs. Since the priority p of the selected leg ID “2” is “1”, the control unit 190c calculates the designated output (adjusted power value) 400W by multiplying the rated output 500W by 80%. Then, the control unit 190c calculates the scheduled output value as 1 kW. For this reason, the total value of the scheduled output values exceeds the current master leg output value of 1 kW. Therefore, the leg IDs “1” and “2” are candidate legs, and the operation is controlled in the master mode. At this time, the failed master leg is also stopped. Thereby, the master leg is switched.

  Subsequently, preconditions different from those in FIG. FIG. 37 is a diagram showing a concept of determining a leg candidate in the case where emphasis is placed on the output power of the leg according to the sixth embodiment of the present invention. First, the output power of the master leg in which an abnormality is detected is 1 kW, and for the leg IDs “1” to “3” to be switched, the leg priority is “3”, “2”, “1”, Assume that the rated output is 1 kW, 700 W, and 500 W. At this time, if the coefficient according to the priority described above is used, three candidate legs are selected as shown in the lower part of FIG.

  Here, in the method using the coefficient according to the priority, the number of candidate legs tends to increase. Therefore, as will be described below, a method for adjusting the number of candidate legs and subtracting the surplus output from the rated output of the lower priority leg of the candidate legs will be described. Thereby, the number of candidate legs can be stabilized, and the number of candidate legs can be reduced in some cases.

  FIG. 38 is a diagram showing a concept of determining leg candidates when the number of leg candidates is fixed according to the sixth embodiment of the present invention. In addition, the upper part (precondition) of FIG. 38 sets the number of selection leg candidates to “2” in addition to the upper part of FIG.

  At this time, the control unit 190c selects leg IDs “1” and “2” which are the top two rated outputs among the three legs. Here, the total value (scheduled output) of the rated output of the selected leg is 1700 W, and the current power value of 1 kW can be covered by the candidate leg. The leg having the lower priority among the selected legs is the leg ID “1” having the priority p = 3. Therefore, the rated output 1 kW of the leg ID “1” is adjusted with surplus power to be 300 W, and the total scheduled output is 1 kW. That is, the number of candidate legs can be suppressed to 2 compared to FIG. This reduces the synchronization load between the legs and increases the stability.

<Seventh Embodiment of the Invention>
The seventh embodiment of the present invention is a modification of the fifth embodiment. The power router according to the seventh embodiment of the present invention is different from the fifth embodiment described above in that the value of the rated output is emphasized when selecting a candidate leg. Therefore, since the configuration of the power router is the same as that of the fifth embodiment, illustration and description thereof are omitted.

  As the number of master legs increases, it becomes more difficult to synchronize between legs, and the stability decreases. It is most stable that the number of master legs is one. However, when the voltage of the DC bus cannot be maintained at the rated value with one master leg, it is operated with a plurality of master legs. Therefore, in Embodiment 7 of the present invention, candidate legs are selected so that the number of master legs is reduced.

  The control unit 190c of the power router according to the seventh exemplary embodiment of the present invention determines that the number of power conversion legs is the smallest among the combinations of power conversion legs in which the total value of the transmittable / receiveable power values can cover the current power value. A power conversion leg belonging to the combination is selected as a candidate leg from among a plurality of power conversion legs other than the master leg. Then, the control unit 190c controls the operation of the selected candidate leg in the master mode.

  FIG. 39 is a diagram showing a concept of determining leg candidates when the number of leg candidates is emphasized according to the seventh embodiment of the present invention. 39 is the same as FIG. 34 and FIG. 36. Here, the case where the rated output is designated output is shown. At this time, the combinations of the legs that can cover the output value 1 kW of the current master leg are only the leg ID “1”, “1” and “2”, “2” and “3”, “1” and “3”. A plurality of combinations such as “,” “1,” “2,” and “3” are possible. Among these, by selecting only the leg ID “1” having the smallest number of candidate legs, the stability after switching the master leg can be increased.

<Other embodiments of the invention>
Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention described above. For example, in the above-described embodiment, the present invention has been described as a hardware configuration, but the present invention is not limited to this. The present invention can also realize arbitrary processing by causing a CPU (Central Processing Unit) to execute a computer program.

  In the above example, the program can be stored and supplied to a computer using various types of non-transitory computer readable media. Non-transitory computer readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (for example, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (for example, magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R / W, DVD (Digital Versatile Disc), BD (Blu-ray (registered trademark) Disc), semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM ( Random Access Memory)). The program may also be supplied to the computer by various types of transitory computer readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

DESCRIPTION OF SYMBOLS 10 Electric power network system 10a Electric power network system 10b Electric power network system 10c Electric power network system 11 Core system 12 Large scale power plant 21 Electric power cell 22 Electric power cell 23 Electric power cell 24 Electric power cell 30 Load 31 House 32 Building 33 Solar power generation panel 34 Wind power generation 35 Power storage facility (storage battery)
35a storage battery 35b storage battery 41 power router 42 power router 43 power router 44 power router 50 management server 51 communication network 52 management server 52a management server 52b management server 521 CPU
522 Memory 523 Communication unit 524 Hard disk 525 Operation program 100 (First) Power router 100a Power router 100b Power router 100c Power router 101 DC bus 102 Smoothing capacitor 103 Voltage sensor 104 Communication bus 110 Leg 111 Power conversion unit 111D Feedback diode 111P Reverse parallel Circuit 111T Thyristor 112 Current sensor 113 Switch 114 Voltage sensor 115 Connection terminal 120 Leg 121 Power conversion unit 122 Current sensor 123 Switch 124 Voltage sensor 125 Connection terminal 130 Leg 135 Connection terminal 140 Leg 145 Connection terminal 150 Leg 151 Power conversion unit 152 Current sensor 153 Switch 154 Voltage sensor 155 Connection terminal 160 Leg 162 Current sensor 163 Switch 164 Electric Sensor 165 Connection terminal 180 Storage unit 180a Storage unit 181 Priority table 181a Priority table 182 Leg information table 190 Control unit 190a Control unit 190b Control unit 190c Control unit 200 Second power router 200a Power router 201 DC bus 210 First leg ( Independent leg)
220 2nd leg (master leg)
230 3rd leg 240 4th leg 245 Connection terminal 250 5th leg 260 6th leg 300 3rd power router 301 DC bus 310 Direct power transmission / reception leg 320 Master leg 350 AC thru leg 360 Master leg 400 4th power router 401 DC bus 410 self-supporting leg 420 master leg 500 fifth power router 501 DC bus 510 leg 600 sixth power router 601 DC bus 610 leg 71A transmission line 71B transmission line 72 distribution line BL branch A leg B leg C leg D leg E leg p1 priority p2 priority p3 final priority

Claims (34)

A power router for asynchronously connecting power cells to an external power system,
A DC bus maintained at a predetermined rated voltage;
One connection end is connected to the DC bus, the other connection end is connected to an external connection partner as an external connection terminal, and a plurality of powers are converted between the one connection end and the other connection end. A power conversion leg,
A controller that controls the power conversion leg in a predetermined operation mode,
The operation mode includes a master mode that is an operation mode for operating the power conversion leg so that the voltage of the DC bus is maintained at the predetermined rated voltage,
The control unit controls operation of at least one of the plurality of power conversion legs in the master mode,
Each of the plurality of power conversion legs is associated with an index value indicating the possibility that the operation mode of the power conversion leg becomes the master mode,
The controller is
The type of connection destination of each power conversion leg or the current operation mode, or at least one of the current state, the past state history, or the future state prediction of the power router, the power conversion leg or its connection partner The index value is determined based on, and the index value is associated with each power conversion leg ,
The predetermined interval, power router, characterized in that to update the index value associated with each of the plurality of power conversion leg. The controller is
The power conversion leg to be operated and controlled in the master mode is selected from the plurality of power conversion legs based on the index value, and the selected power conversion leg is operated and controlled in the master mode. Item 4. The power router according to Item 1. The controller is
The power conversion leg that cannot maintain the voltage of the DC bus at the predetermined rated voltage or the power conversion leg that is expected to be unable to be maintained in the future is selected for operation control in the master mode. The power router according to claim 1, wherein an excluded value to be excluded is assigned to the index value. The controller is
The power conversion leg that cannot maintain the voltage of the DC bus at the predetermined rated voltage or the power conversion leg that is expected to be unable to be maintained in the future is selected for operation control in the master mode. The power router according to claim 1, wherein the power router is excluded from a target. The power router according to any one of claims 1 to 4, further comprising a storage device that stores the identifier of the power conversion leg and the index value in association with each other as a table. The controller is
When the table is updated, referring to the table stored in the storage device, the power conversion leg to be controlled in the master mode is selected from the plurality of power conversion legs, and the selected power The power router according to claim 5, wherein the operation of the conversion leg is controlled in the master mode. The controller is
Based on the index value, selecting a plurality of power conversion legs to be controlled in the master mode from the plurality of power conversion legs, and controlling the selected power conversion legs in the master mode. power router according to any one of claims 1 to 6, wherein. The controller is
The index value is determined based on a power transmission / reception capability or stability of the power conversion leg, a connection destination thereof, or a transmission line connecting the power conversion leg and the connection destination. Power router. The controller is
The power router according to claim 3, wherein the index value is determined based on whether there is a failure in the power conversion leg or a connection destination thereof. The controller is
The power router according to claim 3, wherein the index value is determined based on a probability that the power conversion leg or a connection destination thereof will stop in the future. The controller is
2. The power router according to claim 1, wherein when the type of connection partner of the power conversion leg is a power storage device, the index value is determined based on a remaining capacity of the power storage device. The controller is
The index value is determined based on a management entity of the power generation device or the power storage device when the type of connection destination of the power conversion leg is a power generation device or a power storage device. Power router. The controller is
The index value is determined based on power that can be input and output by the power generation device or the power storage device when the type of connection destination of the power conversion leg is a power generation device or a power storage device. The listed power router. The controller is
The power router according to claim 1, wherein the index value is determined based on a history of magnitude of power transmitted and received in the past at the power conversion leg or a connection destination thereof. The controller is
The index value is determined based on a history of failures that have occurred in the past in either the power conversion leg, its connection destination, or a transmission line connecting the power conversion leg and the connection destination. The listed power router. The controller is
The power router according to claim 1, wherein the index value is determined based on a charge of power transmitted / received between the power conversion leg and a connection destination thereof. A power network system comprising a plurality of power cells having a power router for asynchronously connecting to an external power system,
The power router
A DC bus maintained at a predetermined rated voltage;
One connection end is connected to the DC bus, the other connection end is connected to an external connection partner as an external connection terminal, and a plurality of powers are converted between the one connection end and the other connection end. A power conversion leg,
A controller that controls the power conversion leg in a predetermined operation mode,
The operation mode includes a master mode that is an operation mode for operating the power conversion leg so that the voltage of the DC bus is maintained at the predetermined rated voltage,
The control unit controls operation of at least one of the plurality of power conversion legs in the master mode,
Each of the plurality of power conversion legs is associated with a first index value indicating the possibility that the operation mode of the power conversion leg becomes the master mode,
The first index value is
It is determined based on the type of connection destination of each power conversion leg, or at least one of the current state of the power router, the power conversion leg or its connection partner, the history of the past state, or the prediction of the future state, Is associated with each power conversion leg ,
The predetermined interval, the power network system, characterized in that to update the first index value associated with each of the plurality of power conversion leg. The controller is
Based on the first index value, a power conversion leg to be controlled in the master mode is selected from the plurality of power conversion legs, and the selected power conversion leg is controlled in the master mode. The power network system according to claim 17 . Of the plurality of power conversion legs, the power conversion leg that is no longer able to maintain the voltage of the DC bus at the predetermined rated voltage, or the power conversion leg that is expected to be unable to be maintained in the future, The power network system according to claim 17 or 18 , wherein an exclusion value that is excluded from selection for operation control in the master mode is assigned to the first index value. The power network system includes:
The power network system according to any one of claims 17 to 19 , further comprising: a storage device that stores the power conversion leg and the first index value in association with each other as a table. The power network system includes:
A management device connected to the power router via a network;
The power router
Determining a second index value for each of the plurality of power conversion legs in the power router;
The management device
Determining a third index value for each of the plurality of power conversion legs in the power router;
Either the power router or the management device
The power according to any one of claims 17 to 20 , wherein the first index value is determined for each power conversion leg based on the second index value and the third index value. Network system. The power router
Of the plurality of power conversion legs, for the power conversion leg that is no longer able to determine the second index value, the second priority is lower than the third index value determined by the management device. Assign a metric value,
The management device
Of the plurality of power conversion legs, the power conversion leg that is no longer able to determine the third index value is lower than the second index value determined by the power router. The power network system according to claim 21 , wherein an index value is assigned. The table is
The power network system according to claim 21 or 22 dependent on claim 20 , further comprising an area for managing the second index value and the third index value for each power conversion leg. Wherein the second range of values the index value can be taken, the third power network system according to any one of claims 21 to 23 range of index values possible values are different from each other in. A DC bus maintained at a predetermined rated voltage, one connection end is connected to the DC bus, the other connection end is connected to an external connection partner as an external connection terminal, the one connection end and the other connection end A management device that manages a power router comprising a plurality of power conversion legs that convert power to and from a connection end, and a control unit that controls operation of the power conversion legs in a predetermined operation mode,
Connected to a plurality of power cells having the power router via a network;
The operation mode includes a master mode that is an operation mode for operating the power conversion leg so that the voltage of the DC bus is maintained at the predetermined rated voltage,
Based on an index value indicating the possibility that the operation mode becomes the master mode and associated with each of the plurality of power conversion legs, the master mode is selected from the plurality of power conversion legs. Select at least one power conversion leg to control the operation with
Instructing the power router to control the selected power conversion leg in the master mode,
The index value based on the type of connection destination of each power conversion leg, or at least one of the current state, the history of the past state, or the prediction of the future state in the power router, the power conversion leg or its connection partner And associating the index value with each power conversion leg ,
The predetermined interval, the management apparatus characterized by to update the index value associated with each of the plurality of power conversion leg. A DC bus maintained at a predetermined rated voltage, one connection end is connected to the DC bus, the other connection end is connected to an external connection partner as an external connection terminal, the one connection end and the other connection end In a power router comprising a plurality of power conversion legs that convert power to and from a connection end, and a control unit, an operation method of a power router that controls operation of each power conversion leg in a predetermined operation mode,
The operation mode includes a master mode that is an operation mode for operating the power conversion leg so that the voltage of the DC bus is maintained at the predetermined rated voltage,
Based on an index value indicating the possibility that the operation mode becomes the master mode and associated with each of the plurality of power conversion legs, the master mode is selected from the plurality of power conversion legs. Select at least one power conversion leg to control the operation with
Control the operation of the selected power conversion leg in the master mode,
The type of connection destination of each power conversion leg or the current operation mode, or at least one of the current state, the past state history, or the future state prediction of the power router, the power conversion leg or its connection partner The index value is determined based on, and the index value is associated with each power conversion leg ,
The predetermined intervals, the plurality of methods of operating power router to update the index value associated with each of the power conversion leg. A DC bus maintained at a predetermined rated voltage, one connection end is connected to the DC bus, the other connection end is connected to an external connection partner as an external connection terminal, the one connection end and the other connection end In a power router comprising a plurality of power conversion legs that convert power to and from a connection end, and a control unit, an operation program for a power router that controls operation of each power conversion leg in a predetermined operation mode,
The operation mode includes a master mode that is an operation mode for operating the power conversion leg so that the voltage of the DC bus is maintained at the predetermined rated voltage,
Based on an index value indicating the possibility that the operation mode becomes the master mode and associated with each of the plurality of power conversion legs, the master mode is selected from the plurality of power conversion legs. A process of selecting at least one power conversion leg to be operated and controlled by
Processing for controlling the selected power conversion leg in the master mode;
The type of connection destination of each power conversion leg or the current operation mode, or at least one of the current state, the past state history, or the future state prediction of the power router, the power conversion leg or its connection partner The index value is determined based on the process, and the index value is associated with each power conversion leg,
A process of updating the index value associated with each of the plurality of power conversion legs at a predetermined interval;
An operation program for the power router that causes the control unit to execute. The controller is
When an abnormality related to a master leg that is a power conversion leg that is controlled in the master mode is detected, a current power value that is a current power value of the master leg and a power conversion leg other than the master leg. Is a power conversion leg that is newly controlled to operate in the master mode from among the plurality of power conversion legs other than the master leg based on the transmittable / receivable power value that is a power value that can be transmitted / received and the index value select candidate leg 1 or more and, power router according to any one of claims 1 to 5 or 7 to 16 the selected candidate leg, characterized in that the operation control in the master mode. The controller is
Selecting one or more candidate legs according to the index value from the plurality of power conversion legs other than the master leg;
If the total value of the power transmitting and receiving electric power value in the selected candidate leg the can cover the current power value, the selected candidate leg to claim 28, characterized in that the operation control in the master mode The listed power router. The controller is
From the plurality of power conversion legs other than the master leg, select the candidate legs in descending order of the power transmission / reception possible power value,
An adjusted power value is calculated by adjusting the power transmission / reception possible power value according to the index value associated with each of the selected candidate legs,
The power router according to claim 28 , wherein when the total value of the adjusted power values can cover the current power value, the selected candidate leg is controlled to operate in the master mode. The controller is
The power conversion legs belonging to the combination with the smallest number of power conversion legs among the combinations of the power conversion legs in which the total value of the transmittable / receiveable power values can cover the current power value, other than the master leg Selecting as the candidate leg from among the plurality of power conversion legs of
The power router according to claim 28 , wherein operation control of the selected candidate leg is performed in the master mode. The controller is
When detecting an abnormality related to a master leg that is a power conversion leg that is operation-controlled in the master mode, the master bus voltage is maintained at the predetermined rated voltage based on the index value. One or more candidate legs that are power conversion legs that are newly controlled to operate in the master mode are selected from the plurality of power conversion legs other than the legs, and the selected candidate legs are controlled to operate in the master mode. The power router according to any one of claims 1 to 5 or 7 to 16 . The controller is
When the abnormality related to the master leg is a failure of the master leg, the selected candidate leg is controlled to operate in the master mode, and the operation of the master leg is stopped.
When the abnormality related to the master leg is not a failure of the master leg, the selected candidate leg is operated and controlled in the master mode, and the operation of the master leg is maintained or controlled in another operation mode. The power router according to any one of claims 28 to 32 . The controller is
When the master leg cannot maintain the voltage of the DC bus at the predetermined rated voltage, or when it is expected that it will not be maintained in the future, an abnormality related to the master leg power router according to any one of claims 28 to 33, characterized in that the detection.

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