JP5013891B2 - Grid interconnection device and grid interconnection system - Google Patents

Description

  The present invention relates to a grid interconnection apparatus and a grid interconnection system that convert electric power from a power supply apparatus into predetermined AC power, link the power supply apparatus to a distribution system, and supply power to a load.

  Conventionally, in ordinary households, a power generation device such as a solar power generation device, a wind power generation device, or an engine power generation device is used as a power supply device, and the power supply device is connected to a commercial distribution system to supply power to a load. A system has been proposed.

  Here, in the above-described grid interconnection system, when a power failure occurs on the distribution system side, the system may be in an independent operation state, and power may flow backward from the power supply device to the distribution system. Therefore, in order to ensure safety during maintenance work of the power distribution system, the grid interconnection system detects a single operation state by detecting a change in phase or frequency that occurs when the power supply device shifts to a single operation state. It is configured as follows. And when the said grid connection system detects the said independent operation state, it stops a distributed power supply, or has disconnected from the power distribution system, and has prevented the isolated operation.

  However, when a plurality of power supply devices are linked to a certain range of distribution system, for example, when the power supplied from the power supply device and the power consumption of the load in the distribution system are balanced, the power distribution system In some cases, the isolated operation state cannot be detected despite the occurrence of.

In recent years, a “transfer blocking method” has been proposed as a countermeasure (for example, see Patent Document 1). In the grid connection system to which the “transfer interruption method” is applied, when a power failure occurs in the distribution system, the power interruption information for notifying the occurrence of the power failure is received from the transfer interruption device provided in the distribution system. By stopping the operation of the power supply device, it is configured to prevent an isolated operation.
JP 2005-198446 A

  However, in the grid interconnection system to which the above-described “transfer interruption method” is applied, the power supply device is in accordance with the power failure information from the transfer interruption device on the distribution system side, even though the power supply device is operable. Since the operation must be completely stopped, there is a problem that the utilization efficiency of the power supply device is reduced.

  In particular, when the power supply is a fuel cell that takes time to restart, operation is completely stopped even if a power failure occurs for a short time (for example, about 5 minutes), and a long time is required for restart after power recovery ( For example, it takes about 30 minutes), and the utilization efficiency of the power supply apparatus has been greatly reduced.

  Some power supply devices are adversely affected by a sudden stop. For example, if the fuel cell is suddenly stopped, the deterioration of the power generation module is promoted. In addition, engine generators having large rotational inertia are adversely affected by an increase in fuel consumption due to engine brakes and wear of mechanical brakes due to sudden stops. Therefore, it is desirable to protect the power supply device by avoiding a sudden stop as much as possible.

  Therefore, the present invention has been made in view of the above points, while preventing isolated operation according to the state of the power failure that occurred in the power distribution system and other power distribution systems connected to the grid interconnection device, An object of the present invention is to provide a grid interconnection device and a grid interconnection system capable of improving the utilization efficiency of a power supply device.

  The first feature of the present invention is that the power from the power supply device (power supply device 110) is converted into predetermined AC power, and the power supply device is connected to the distribution system (distribution system X) to supply power to the load. A system unit (system interconnection device 102) that receives power outage information including power outage state information indicating a state of power outage, and that is resolved from the power distribution system based on the power outage state information. And an operation control unit (operation control unit 144) that performs an independent operation of supplying power to the load from the power supply device.

  According to this feature, when a power failure occurs in the distribution system or other distribution system to which the grid interconnection device is connected, the power supply device is disconnected from the distribution system according to the power failure state information indicating the state of the power failure. The self-supporting operation is performed in which power is supplied from the power supply device to the load. Therefore, according to such a feature, the power supply device is connected to the power distribution device while preventing isolated operation by disconnecting according to the state of the power failure occurring in the predetermined distribution system and other distribution systems to which the grid interconnection device is connected. While improving utilization efficiency, the bad influence by a stop can be avoided and a power supply device can be protected.

  The second feature of the present invention relates to the first feature, wherein the power failure state information is factor information indicating a factor that caused the power failure, and the factor information included in the power failure information as the power failure state information is a predetermined factor. In the case of information, the gist is to perform the autonomous operation.

  According to such a feature, the grid interconnection system performs autonomous operation when the factor information included in the power failure information is predetermined factor information. Therefore, it is possible to appropriately perform the independent operation according to various power failure factors.

  A third feature of the present invention relates to the first or second feature, wherein the power failure state information is power failure time information indicating a power failure time and identification information of a distribution system in which the power failure has occurred, and the operation control unit The identification information of the distribution system included in the power outage information as power outage state information is the identification information of the distribution system connected to the grid interconnection device, and the power outage time information is less than a predetermined threshold value. In some cases, the gist is to perform the autonomous operation.

  According to this feature, when a power failure occurs in the distribution system to which the grid interconnection device is linked, if it is less than a predetermined time, the power is disconnected and the operation is continued without stopping. Therefore, according to the state of the power failure that occurred in the predetermined distribution system and other distribution systems to which the grid interconnection device is connected, while improving the efficiency of use of the power supply device while preventing isolated operation by disconnecting It is possible to avoid the adverse effects due to the stop and protect the power supply device.

  In addition, a fourth feature of the present invention relates to any one of the first to third features, wherein the load is a plurality of loads having priorities, and the operation control unit performs the independent operation. In this case, the gist is to supply power to the high priority load. According to such a feature, the grid interconnection device controls only a high priority load as a power supply destination when performing independent operation, and therefore continuously operates without stopping the important load even in the event of a power failure. Can do.

  The fifth feature of the present invention is that the grid interconnection system includes a power supply device and the grid interconnection device according to any one of the first to fourth features.

  According to the features of the present invention, according to the state of the power failure that occurred in the power distribution system and other power distribution system connected to the grid interconnection device, while improving the use efficiency of the power supply device while preventing isolated operation, It is possible to provide a grid interconnection device and a grid interconnection system capable of avoiding adverse effects due to the stop and protecting the power supply apparatus.

  An embodiment of the present invention will be described. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic.

(Overall schematic configuration of power system according to an embodiment of the present invention)
FIG. 1 shows an overall schematic configuration of a power system according to the present embodiment. As shown in FIG. 1, the substation 1 has a plurality of distribution systems A to X under its control, and supplies power from the high-voltage transmission line to the distribution systems A to X. In addition, the substation 1 includes a power failure management device (transfer interruption device) 10.

  When a power failure occurs in any of the distribution systems A to X, the power failure management apparatus 10 notifies all of the distribution systems A to X as a transfer interruption method. Specifically, when a power failure occurs due to a lightning strike or the like in any of the distribution systems A to X under the substation 1, the power failure management apparatus 10 supplies power to all the power supply devices in each of the distribution systems A to X. Send outage information to notify that has occurred. Here, the power outage information according to the present embodiment includes at least one or more pieces of information illustrated in FIG. 2 as power outage state information indicating the state of the power outage. The “occurrence location” (identification information) indicates the identification information of the distribution system. “Factor” (factor information) indicates the cause of the power failure. “Power outage time” (power outage time information) indicates a time when power is restored from a time when the power outage starts, a time during which the power outage occurs, and the like.

  Further, as shown in FIG. 3, the power failure information may be transmitted by updating the power failure state information with the lapse of time ta to tb from the time t0 when the power failure occurs. In addition to the above, the power failure information includes the following information as power failure state information.

1. Operation information-“Without / without power failure”: Indicates whether or not a power failure has occurred (cut off).

2. District information • “Business operator information”: Indicates a business operator that supplies power (for example, Kansai Electric Power).

3. Specific information • “Area information”: Indicates the area where the power failure occurred (for example, Hirakata City, Osaka Prefecture).

・ "Target model": Model of the power supply device subject to power failure (for example, fuel cell, wind power generator)
In the example of FIG. 1, the power failure management device 10 transmits power failure information to the distribution system X via the signal line 16. In the example of FIG. 1, an image in which a power failure occurs due to a lightning strike in the distribution system A is shown.

  In the power distribution system X, power is supplied to the consumers 100a to 100c that are power consumers through the power transmission line 15 provided.

  The customers 100a to 100c are, for example, ordinary households provided with a power supply device, and the provided power supply device is connected to the power distribution system X. Further, the customers 100 a to 100 c receive the power outage information transmitted from the power outage management apparatus 10 through the signal line 16. The signal line 16 may be constituted by a power line communication using the power transmission line 15, a telephone line, a wired line such as an optical fiber, or may be constituted by a wireless line such as a mobile phone or a wireless LAN. In addition, distribution by radio waves such as BS, CS, TV, radio, radio clock, etc. is also included. In general, radio waves are distributed over a wide area. However, because the power outage information includes the above-mentioned “operator information” and “area information”, it is distributed only to power supply devices in a specific area. Has the same effect as

(Configuration of customer according to this embodiment)
Next, the configuration of the customers 100a to 100c including the power supply device will be described. In addition, since the power distribution configuration in the customers 100a to 100c is substantially the same configuration, the description will be given focusing on the customer 100a.

  FIG. 4 is a block diagram showing the configuration of the customer 100a. As shown in FIG. 4, a single-phase three-wire AC voltage is supplied from the distribution system X to the customer 100a. Further, the customer 100a includes a power supply device 110, a DC / DC converter 120, an inverter 130, a control unit 140, a system interconnection breaker CB1, general loads Wb0 to Wb3, and interconnection relays Ry1 to Ry3. And a relay Ry4. The DC / DC converter 120, the inverter 130, the control unit 140, and the interconnection relay Ry1 constitute the grid interconnection device 102. In addition, the grid interconnection system 101 is configured by the grid interconnection apparatus 102 and the power supply apparatus 110.

  In addition, the grid interconnection system 101 according to the present embodiment is provided in a customer 100a including the power supply device 110, and the power supply device 110 is connected to the distribution system in the plurality of distribution systems A to X that supply power from the substation 1. Linked to X (predetermined power distribution system). Further, the grid interconnection system 101 disconnects the power supply device from the distribution system X when a power failure occurs in the interconnection system X to be linked. Here, the grid connection state refers to a state in which the power supply device in the customer 100a is electrically connected to the power system under control of the substation 1, and the isolated operation state refers to power feeding from the substation 1. Indicates that the grid interconnection system 101 in the customer 100a is supplying power to the load.

  The power supply device 110 is assumed to be a direct current power generation device such as a solar power generation system or a fuel cell power generation system.

  The DC / DC converter 120 converts the output voltage output from the power supply device 110 into a DC voltage having a desired voltage value and outputs the DC voltage to the inverter 130. Further, the DC / DC converter 120 outputs DC power to the general load Wb0 that is a DC load under the control of the control unit 140.

  The inverter 130 converts the DC voltage output from the DC / DC converter 120 into an AC voltage (for example, AC 200 V) and outputs the AC voltage. Further, the inverter 130 outputs the AC voltage to be converted substantially equal to the commercial AC voltage supplied from the distribution system X. In addition, when outputting an AC voltage, the inverter 130 switches between voltage type current control and voltage type voltage control according to an instruction from the control unit 140.

  The control unit 140 is connected to the DC / DC converter 120, the inverter 130, the interconnection relays Ry1 to Ry3, and the relay Ry4. Further, the control unit 140 receives the power outage information transmitted from the power outage management apparatus 10, and based on the received power outage information, switches the output destination of the DC / DC converter 120, outputs conversion control of the inverter 130, Open / close control of the system relays Ry1 to Ry3 and the relay Ry4 is performed. Further, the control unit 140 is connected to the general loads Wb0 to Wb3, and notifies the power consumption and the like from the general loads Wb0 to Wb3.

  The grid connection breaker CB1 detects and opens an overcurrent, and protects the power transmission line 15 and the like.

  The general loads Wb0 to Wb3 are home electric appliances that are loads. In the present embodiment, the general load Wb0 is a DC load, such as a power storage device or a snow melting heater. The general loads Wb1 to Wb3 are AC loads, such as a refrigerator, a PC server, an AC heater device, a lighting device, a TV, and an air conditioner. In general, the general loads Wb1 to Wb3 are driven by both the AC voltage output from the inverter 130 and the AC voltage supplied from the power distribution system X. In the present embodiment, priorities are provided in advance to the plurality of general loads Wb0 to Wb3.

  Specifically, the general load Wb1 has the highest priority, for example, a PC server or a refrigerator. Further, the general loads Wb1 to Wb3, which are AC loads, are arranged according to the priority order. Specifically, as shown in FIG. 4, they are arranged so as to be connected to the wiring from the power supply apparatus 110 side to the distribution system X side according to the priority order. Further, according to the priority order, for example, the interconnection relay Ry2 is interposed between the loads of the general load Wb1 and the general load Wb2, and the interconnection relay Ry2 is opened in the event of a power failure, and the power supply device 110 is connected to the uninterruptible power supply device. (UPS), it is possible to supply power continuously even during a power failure.

  The interconnection relays Ry1 to Ry3 are opened and closed under the control of the control unit 140. Further, the interconnection relay Ry1 is opened to disconnect the power supply device 110 side from the distribution system X side. In addition, when the interconnection relay Ry1 is opened, supply of power from the power supply device 110 to the general loads Wb2 to Wb3 that are AC loads is stopped.

  The relay Ry4 is connected when the interconnection relay Ry2 is opened. Specifically, when the interconnection relay Ry2 is opened and the electric power from the power supply device 110 is output from the inverter 130, the output from the inverter 130 is normally 200V at the U-V end. When the power is supplied to the general load Wb1, the inverter 130 switches the output voltage from 200V to 100V and supplies the relay Ry4 with connection.

(Configuration of control unit)
Next, the configuration of the control unit 140 will be specifically described with reference to FIG. Hereinafter, portions related to the present invention will be mainly described. Therefore, it should be noted that the control unit 140 may include a functional block (such as a power supply unit) that is essential for realizing the function as the control unit and that is not illustrated or omitted.

As shown in FIG. 5, the control unit 140 includes a communication unit 141, a storage unit 142, a selection unit 143, and an operation control unit 144.
The communication unit 141 receives the power failure information transmitted from the power failure management device 10. In this embodiment, the communication part 141 comprises the receiving part which receives the power failure information containing the power failure state information which shows the state of the power failure which generate | occur | produced in the some power distribution system A thru | or X.

  The storage unit 142 stores in advance “business operator information”, “area information”, and “system information (distribution system X)” to which the grid interconnection device 102 belongs. In addition, as shown in FIG. 6, “power failure time threshold” (predetermined threshold), “specific factor (DC power operation)” (predetermined factor information), and “specific factor (AC power operation)” (predetermined Factor information).

  The “power failure time threshold value” is a threshold value for determining whether the power failure time is long or short. The “specific factor (DC power operation)” and the “specific factor (AC power operation)” are used when determining whether or not to perform a self-contained DC power operation or an AC power operation described later.

  The “specific factor (DC power operation)” is information indicating the cause of the power failure, and for example, “snow damage” or the like is stored. The “specific factor (AC power operation)” is information indicating the cause of the power outage as well as the “specific factor (DC power operation)”, and stores, for example, “fire”. These pieces of information are the same as the information included in the power outage information as the power outage state information, and are stored in advance in the storage unit 142 by the user. The storage unit 142 may be an internal storage device such as a RAM or an external storage device such as an HD. In the present embodiment, the storage unit 142 constitutes a storage unit that stores predetermined factor information in advance.

  Based on the power outage state information included in the power outage information received by the communication unit 141, the selection unit 143 connects the power supply device 110 to the power distribution systems A to X and supplies power to the plurality of general loads Wb1 to Wb3. Operation, self-sustained operation in which power is disconnected from at least one general load (for example, general load Wb1) only from the power supply device 110, and power is supplied from the distribution system X and the power supply device 110 to all general loads. Select one of the stop and stop operations.

  Here, “interconnection operation” refers to an operation method in the case where power from the power supply device 110 in the customer 100a and power from the distribution system X are used together and supplied to the general loads Wb1 to Wb3. .

  “Self-sustained operation” refers to an operation method in the case where power is supplied to at least one general load Wb0 to Wb3 using only the power supply device 110 in the customer 100a. Note that when the operation is performed in “self-sustaining operation”, the general loads Wb0 to Wb3 are supplied from either the power from the power supply device 110 or the power from the distribution system X.

  The “operation stop” indicates an operation method for stopping the operation of the power supply device 110 in the customer 100a.

  In addition, the selection unit 143 selects the general loads Wb0 to Wb3 having a high priority set in advance as the power supply destination in the self-sustained operation, and supplies power to the selected general load (for example, the general load Wb1). Power is supplied only from 110. Note that specific power supply control is executed by an operation control unit 144 described later.

  The selection unit 143 includes power outage state information such as “occurrence location”, “factor”, “power outage time” included in the power outage information received by the communication unit 141, and “power outage time threshold” stored in the storage unit 142, Based on the “specific factor (DC power operation)” and “specific factor (AC power operation)”, the power supply destination from the power supply device 110 in “self-sustaining operation” according to the priority order of the general loads Wb0 to Wb3 Select. Specifically, the selection unit 143 indicates that the “occurrence location” of the distribution system included in the power outage information as the power outage state information is identification information of the predetermined power distribution system X to which the system interconnection device 102 is connected, and “power outage” When “Time” is “Power failure time threshold” (less than a predetermined time), “Self-sustained operation” is selected.

  Further, when the factor information included in the power outage information as the power outage state information is the predetermined factor information stored in the storage unit 142, the selecting unit 143 selects “self-sustained operation”. Specifically, the selection unit 143 determines that the “specific factor (DC power operation)” stored in the storage unit 142 is the “factor” included in the power failure information received by the communication unit 141 in “self-sustaining operation”. If it is included, “independent DC power operation” is selected. If “specific factor (AC power operation)” is included, “independent AC power operation” is selected. Note that, in the present embodiment, the above-described “independent DC power operation” and “independent AC power operation” are both described as “independent operation”.

  Here, “independent DC power operation” indicates an operation method in which the power supply destination of the power supply device 110 is a general load Wb0 that is a DC load. In this case, the DC / DC converter 120 outputs DC power to the general load Wb0. Moreover, the inverter 130 does not output an alternating voltage.

  “Self-supporting AC power operation” refers to an operation method in which an AC load is selected as the power supply destination of the power supply device 110 and is supplied to the general load Wb1 and not supplied to the general loads Wb2 to Wb3, for example. In this case, power is not supplied to the general load Wb0 that is a DC load.

  Thus, the selection unit 143 selects “independent DC power operation” or “independent AC power operation” in “independent operation”, and selects a transmission destination of power from the power supply device 110. In addition, when the selection unit 143 selects “independent DC power operation” and “independent AC power operation” in the above-described “interconnection operation”, “operation stop”, and “independent operation”, the selection result is displayed as an operation control unit. 144 is notified.

Based on the power failure state information, the operation control unit 144 disconnects from the power distribution system X and performs a self-sustaining operation in which power is supplied from the power supply device 110 to the load. Specifically, the operation control unit 144 controls the power supply destinations of the power distribution system X and the power supply device 110 in accordance with “interconnection operation”, “self-sustaining operation”, or “operation stop” selected by the selection unit 143. In addition, the operation control unit 144 controls only a load having a high priority selected by the selection unit 143 as a power supply destination of the power supply apparatus 110 in “self-sustained operation”. Upon receiving a notification that the “interconnection operation” is to be executed, the connection relays Ry1 to Ry3 are connected and the relay Ry4 is opened. Further, the operation control unit 144 performs control so that the AC voltage output from the inverter 130 is output at 200V.

  Further, when the operation control unit 144 receives a notification from the selection unit 143 that the “independent DC power operation” of “independent operation” is to be performed, the operation control unit 144 opens the interconnection relay Ry1 and stops the output of the inverter 130. Further, the operation control unit 144 changes the output destination of the DC / DC converter 120 to a general load Wb0 that is a DC load. At this time, the operation control unit 144 performs control so that the DC voltage output from the DC / DC converter 120 is output at a desired voltage value.

  In addition, when the operation control unit 144 receives a notification from the selection unit 143 to execute “self-sustained AC power operation” of “self-sustained operation”, the connection relay Ry1 is connected, and the connection relays Ry2 to Ry3 are opened, Connect Ry4. Further, the operation control unit 144 performs control so that the AC voltage output from the inverter 130 is output at 100V. At this time, the inverter 130 switches the output control of the AC voltage from the voltage type current control to the voltage type voltage control. Further, when the operation control unit 144 receives a notification from the selection unit 143 that the “operation stop” is executed, the operation control unit 144 opens the interconnection relay Ry1 and operates the power supply device 110, the DC / DC converter 120, and the inverter 130. Stop.

  In addition, in the “self-sustaining AC power operation” of “self-sustained operation”, the operation control unit 144 is not limited to controlling the interconnection relays Ry1 to Ry3 and the relay Ry4, and stops and stops the operation of the load with low priority. A load other than the load (general load Wb1) may be controlled as a power supply destination of the power supply device 110. Specifically, the operation control unit 144 opens the interconnection relay Ry3 when performing the “self-supporting AC power operation”, and when the load is overloaded according to the power from the power supply device 110, For example, the general loads Wb2 to Wb3 may be instructed to stop by communicating with the general loads Wb2 to Wb3.

(Operation of the grid interconnection system according to the first embodiment)
Next, the operation of the grid interconnection system 101 having the above-described configuration will be described with reference to FIG. Specifically, the control operation when the power failure information transmitted from the power failure management apparatus 10 is received in the grid interconnection system 101 will be described.

(Control action when power outage information is received)
In step S <b> 11, the communication unit 141 receives the power outage information transmitted from the power outage management device 10 and transmits the power outage information to the selection unit 143.

  In step S <b> 13, the selection unit 143 stores the “occurrence location” included in the power failure information in the other power distribution system and the “factor” included in the power failure information in the storage unit 142. It is determined whether or not “specific factor (DC power operation)” and “specific factor (AC power operation)”. By the operation of the selection unit 143, it is estimated whether there is a possibility that the power distribution system X may be interrupted.

  In step S <b> 15, the selection unit 143 determines whether or not the power distribution system X is the other power distribution system and is not the “specific factor”.

  If the selection unit 143 determines that the power distribution system X is in step S17, is the “power failure time” included in the power failure information less than the “power failure time threshold” stored in the storage unit 142? Determine whether or not.

  In step S19, the selection unit 143 selects “self-sustaining operation”. Further, the selection unit 143 selects “independent DC power operation” when “specific factor (DC power operation)” stored in the storage unit 142 is included as the “factor” included in the power failure information. If “specific factor (AC power operation)” is included, “independent AC power operation” is selected. The selection unit 143 notifies the operation control unit 144 of the selection result. In addition, the operation control unit 144 opens and closes the interconnection relays Ry1 to Ry3 and the relay Ry4 according to the “self-sustained DC power operation” or “self-supporting AC power operation” notified by the selection unit 143, and DC / DC The outputs of the converter 120 and the inverter 130 are controlled.

  In step S <b> 21, the selection unit 143 selects “operation stop” and notifies the operation control unit 144 of the selection result. In addition, the operation control unit 144 opens the interconnection relay Ry1 and stops the operation of the power supply device 110, the DC / DC converter 120, and the inverter 130.

  In step S23, the selection unit 143 selects “interconnection operation” and notifies the operation control unit 144 of the selection result. In addition, when the operation control unit 144 receives a notification from the selection unit 143 that the “interconnection operation” is performed, the operation control unit 144 connects the interconnection relays Ry1 to Ry3 and opens the relay Ry4. Further, the operation control unit 144 performs control so that the AC voltage output from the inverter 130 is output at approximately 200V.

  In this way, in the grid interconnection system 101, when the power failure information is received, the selection unit 143 selects any one of “self-sustaining operation”, “operation stop”, and “interconnection operation” and performs the selection. Depending on the result, the operation control unit 144 controls the power supply destination of the power from the power supply device 110. In addition, the operations in steps S11 to S23 are repeatedly executed every time power failure information is received.

(Selective operation of independent AC output operation and independent DC output operation for independent operation)
Next, the selection operation of “independent DC power operation” or “independent AC power operation” of “independent operation” performed by the selection unit 143 in step S19 described above will be specifically described with reference to FIG.

  First, in step S191, when the “specific factor (DC power operation)” stored in the storage unit 142 is included as the “factor” included in the power failure information, the selection unit 143 selects “independent DC power operation”. When “specific factor (AC power operation)” is included, “independent AC power operation” is selected. Note that the selection unit 143 selects “independent AC power operation” when neither factor is included. The selection unit 143 notifies the operation control unit 144 of the selection result.

  In step S193, when the operation control unit 144 receives a notification from the selection unit 143 that the “independent DC power operation” is to be executed, the operation control unit 144 opens the interconnection relay Ry1 and stops the output of the inverter 130. Further, the operation control unit 144 changes the output destination of the DC / DC converter 120 to a general load Wb0 that is a DC load. At this time, the operation control unit 144 performs control so that the DC voltage output from the DC / DC converter 120 is output at a desired voltage value in the general load Wb0.

  In step S195, when the operation control unit 144 receives a notification from the selection unit 143 that the “self-sustained AC power operation” of “self-sustained operation” is executed, the connection relay Ry1 is connected and the connection relays Ry2 to Ry3 are opened. , Relay Ry4 is connected. Further, the operation control unit 144 performs control so that the AC voltage output from the inverter 130 is output at 100V. Further, the inverter 130 switches the output control of the AC voltage from the voltage type current control to the voltage type voltage control.

  Here, FIG. 9 shows a timing chart when the grid interconnection system 101 executes the above-described “independent DC power operation”. FIG. 10 shows a timing chart when the above-described “independent AC power operation” is executed. 9 to 10, the “power failure state signal” in the self-distribution system X indicates a power failure state when “off” and a power recovery state (normal power supply state) when “on”. Further, “Ry1 state” to “Ry4 state” indicate an open state when “off” and a connected state when “on” in the interconnection relays Ry1 to Ry4. Further, “DC power output (Wb0)” indicates that the power from the DC / DC converter 120 to the general load Wb0 of the DC load is “off” and the output state is “off”. Further, “AC power output” in the inverter 130 indicates a stop state when “off” and an output state when “on”. In addition, “power generation device output” in the power supply device 110 indicates a stop state when “off” and an output state when “on”.

  As shown in FIG. 9, in the grid interconnection system 101, after a power failure occurs in the self-distribution system X at time t0, the grid relay Ry1 is opened and the inverter 130 stops outputting at time t1. Further, the DC / DC converter 120 starts output. At this time, “independent DC power operation” is started. Further, at time t2, the self-distribution system X is restored, and at time t3, the interconnection relay Ry1 is connected and the inverter 130 starts outputting. Further, the DC / DC converter 120 stops the output, and the “independent DC power operation” is completed.

  As shown in FIG. 10, in the grid interconnection system 101, after a power failure occurs in the self-distribution system X at time t0, the grid relay Ry2 is opened and the grid relay Ry4 is connected at time t1. Further, the inverter 130 switches from voltage type current control to voltage type voltage control. At this time, “independent AC power operation” is started. In addition, at time t2, the self-distribution system X is restored, and at time t3, the interconnection relay Ry2 is connected and the interconnection relay Ry4 is opened. Further, the inverter 130 switches from the voltage type voltage control to the voltage type current control, and the “independent DC power operation” is completed.

  FIG. 11 shows a timing chart when a power failure occurs in another distribution system in the grid interconnection system 101 and “self-sustained AC power operation” is executed. In FIG. 11, the “power failure state signal of other distribution system” indicates a power failure state by “off” and a power recovery state (normal power supply state) by “on” in the own distribution system X. The “AC power output (Wb1)” indicates that the power from the inverter 130 to the general load Wb1 of the AC load is “off” and the output is stopped. As shown in FIG. 11, in the grid interconnection system 101, a power failure occurs in another distribution system at time t0, the grid relay Ry2 is opened, and the grid relay Ry4 is connected. Further, the inverter 130 switches from voltage type current control to voltage type voltage control. At this time, “independent AC power operation” is started. Further, at time t1, based on the information of “power outage time” included in the power outage information, it is estimated from the power recovery time that no power outage will occur in the own power distribution system X, and “interconnection operation” is executed. . Then, at time t2, the other distribution system is restored.

As shown in the timing charts of FIGS. 9 to 11, the grid interconnection system 101 can be continuously operated without stopping the operation of the power supply device 110 even if a power failure occurs in the self-distribution system X. become.
(Operations and effects of the grid interconnection system according to the first embodiment)
According to the grid interconnection system 101 according to the present embodiment, based on the received power outage information, “interconnection operation” in which the power supply apparatus 110 is linked to the distribution system, or the power supply apparatus 110 disconnected from the distribution system. “Self-sustained operation” in which power is supplied only from the power source and “Operation stop” in which power supply is stopped are selected, and the power supply destination of the power distribution system X and the power supply device 110 is controlled according to the selection result.

  In other words, in the grid interconnection system 101, when a power failure occurs in the distribution system X or other distribution systems A to B to which the grid interconnection device 102 is linked, a more appropriate power supply destination is selected according to the state of the power failure. For example, when “self-sustained operation” is selected, the power supply device 110 is disconnected from the power distribution system X, and the power supply device 110 is continuously operated to supply power to at least one load.

  Therefore, according to the grid interconnection system 101, it is possible to disconnect or link in accordance with the state of the power failure that occurs in the distribution system X and the other distribution systems A to B to which the grid interconnection device 102 is linked. In addition, the operation of the power supply device 110 can be continued and the use efficiency can be improved while appropriately switching the power supply destination while preventing the isolated operation, and the adverse effect due to the stop can be avoided and the power supply device can be protected.

  In addition, the grid interconnection system 101 is a highly reliable grid interconnection system in which sudden load fluctuations are reduced as much as possible with respect to the power generation amount to the grid by stopping and operating the power supply device 110 as in the prior art. .

  The grid interconnection system 101 according to the present embodiment selects “self-sustained operation” when the “factor” included in the power failure information is a “specific factor” stored in advance. Therefore, “self-sustained operation” can be appropriately selected in accordance with various power failure factors.

  In addition, according to the grid interconnection system 101 according to the present embodiment, when “self-sustained operation” is selected, a load with a high priority (for example, the general load Wb1) provided in advance, that is, only an important load is supplied to the power supply destination. Therefore, it is possible to supply power to an important load according to “factor” and priority.

  For example, the power line cut (snow damage) may occur due to snow on the Sea of Japan side where the amount of snow is large. In this case, it is conceivable that snow is also accumulated in the vicinity, so it is desirable to give priority to the power supply to the snow melting device by the heater installed in the attic.

  Further, the surplus power may be used for charging the storage battery or storing hot water. Also, if there is a fire in the vicinity, there is a high possibility that a power outage will eventually occur, so it is considered desirable to shift to “self-sustaining operation”. Also, in the case of landslides or lightning strikes, it may be difficult to tell if the area is far away, so it is important for users to switch to “self-sustaining operation” and continue to supply power to important loads autonomously. A better choice.

  Further, in the grid interconnection system 101 according to the present embodiment, the “occurrence location” included in the power failure information is a predetermined distribution system X linked to the grid interconnection device 102, and the “power failure time” is predetermined. If it is the threshold value, “independent operation” is selected. Therefore, when the power failure occurs in the distribution system X to which the grid interconnection device 102 is linked, the grid interconnection system 101 is disconnected if it is less than the power failure time threshold, and the power supply device 110 is operated without stopping. Therefore, it is possible to improve the utilization efficiency of the power supply device 110 while preventing the isolated operation and to avoid the adverse effects due to the stop and protect the power supply device.

[Second Embodiment]
Hereinafter, the configuration of the second embodiment of the present invention will be described by focusing on the differences from the first embodiment described above.

(System interconnection system according to the second embodiment)
In the grid interconnection system 101 according to the first embodiment, the power supply device 110 is configured to output DC power. However, in the present embodiment, a wind turbine generator, an engine generator, a gas turbine generator, or the like is used. Thus, it is comprised so that alternating current power may be output.

  In the grid interconnection system 101 according to the first embodiment, the DC / DC converter 120 and the inverter 130 are provided. However, in the grid interconnection system 101 according to the present embodiment, the DC / DC converter 120, Instead of the inverter 130, an AC / AC converter 120a is provided as shown in FIG.

  The AC / AC converter 120a converts the AC voltage output from the power supply device 110 into a desired AC voltage (for example, AC 200V) and outputs the AC voltage. The AC / AC converter 120a is assumed to be a power conversion device that directly converts AC power into predetermined AC power, such as a cycloconverter or a matrix converter.

  Moreover, although the memory | storage part 142 which concerns on 1st Embodiment was comprised so that the information corresponding to a specific factor (DC power operation) and the information corresponding to a specific factor (AC power operation) may be memorize | stored as a specific factor. In this embodiment, the information corresponding to the specific factor (AC power operation 1) and the information corresponding to the specific factor (AC power operation 2) are stored.

  Moreover, although the case where the general load Wb0 according to the first embodiment is a DC load has been described as an example, in the present embodiment, the general load Wb0 is an AC heater such as an AC 200V load as an AC load. .

(Selection operation of independent AC output operation 1 and independent AC output operation 2 of independent operation)
The operation of the grid interconnection system 101 according to the present embodiment will be described. Specifically, the selection operation of “independent AC output operation 1” and “independent AC output operation 2” during the independent operation will be described.

  The grid interconnection system 101 according to the present embodiment is the same as the grid interconnection system 101 according to the first embodiment except for the operations of steps S191 to S195 of the grid interconnection system 101 according to the first embodiment. Therefore, the operation of steps S191 to S195 will be described.

  In step S191, when the “specific factor (AC power operation 1)” stored in the storage unit 142 is included as the “factor” included in the power failure information, the selection unit 143 selects “independent AC power operation 1”. "Is selected, and when" specific factor (AC power operation 2) "is included," independent AC power operation 2 "is selected. Note that the selection unit 143 may select “independent AC power operation 2” when neither factor is included. The selection unit 143 notifies the operation control unit 144 of the selection result.

  In step S193, when the operation control unit 144 receives a notification from the selection unit 143 that the “independent AC power operation 1” is executed, the operation control unit 144 opens the interconnection relay Ry1 and sets the output destination of the AC / AC converter 120a to the AC load. To the general load Wb0. At this time, the operation control unit 144 controls the AC voltage output from the AC / AC converter 120a to be output at a desired voltage value (for example, AC 200V) at the general load Wb0.

  In step S 195, when the operation control unit 144 receives a notification from the selection unit 143 that the “independent AC power operation 2” is executed, the connection relay Ry 1 is connected, the connection relays Ry 2 to Ry 3 are opened, and the relay Ry 4 is opened. Connecting. Further, the operation control unit 144 performs control so that the AC voltage output from the AC / AC converter 120a is output at 100V.

(Operation and effect of the grid interconnection system according to the second embodiment)
In the grid interconnection system 101 according to the present embodiment, when the independent operation is performed by the two operation methods of “independent AC power operation 1” and “independent AC power operation 2”, the output voltage and the output destination of the AC power are output. To supply power to the load.

  Therefore, the grid interconnection system 101 disconnects from the distribution system X and stops the power supply apparatus 110 if a power failure occurs in the distribution system X to which the grid interconnection device 102 is linked, if the power failure time is less than the power failure time threshold. Without operation, the operation is continued in “AC power operation 1” or “AC power operation 2”. As described above, according to such a system system 101, it is possible to improve the utilization efficiency of the power supply device 110 while preventing an isolated operation, to avoid an adverse effect due to the stop, and to protect the power supply device.

(Other embodiments)
As described above, the content of the present invention has been disclosed through one embodiment of the present invention. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments will be apparent to those skilled in the art.

  In the grid interconnection system 101 according to the above-described embodiment, the operation at the time of power failure has been mainly described, but it is also useful at the time of power recovery. For example, when a power failure is systematically executed by maintenance work such as maintenance, it is estimated that power is restored at a more accurate time. Therefore, based on the “power failure time” included in the power failure information, the power supply device 110 can be activated in advance in accordance with the power recovery time. In particular, in the case where the power supply device 110 is a fuel cell, there is a problem that it takes a long time to reach the maximum generated power because the generated power is gradually increased by finely adjusting the gas supply amount and the temperature adjustment. In the case of the prior art, there is no choice but to wait for the power recovery time. However, in the grid interconnection system 101, starting the fuel cell in advance by starting in advance from the power recovery time included in the power failure information. Utilization rate and effective use can be performed.

  In addition, in order to acquire more accurate power recovery time, a voltage sensor is provided on the distribution system X side of the grid connection breaker CB1 as the acquisition means, and the voltage at the time of power recovery is measured and monitored. Also good.

  Further, in the grid interconnection system 101 according to the first embodiment described above, the grid interconnection apparatus 102 separately performs “independent DC power operation” and “independent AC power operation” as a mode during “independent operation”. Although it is configured to operate, it may be operated in combination with “DC power operation” and “AC power operation”. For example, when the power supply device is a fuel cell, an engine generator, or the like, the output power cannot follow a sudden change in the load. Therefore, when the load is suddenly reduced, surplus power is generated. Since these power supply devices are not allowed to reversely flow into the system, this surplus power may be configured to be supplied to a DC heater, an AC heater, a battery, or the like.

  Further, in the grid interconnection system 101 according to the first embodiment described above, the grid interconnection device 102 has described the “occurrence location” (identification information) as the identification information of the distribution system. “Information”, “area information” of the specific information, and the like may be used together as identification information for identifying the distribution system.

  For example, in the grid interconnection system 101 according to the first embodiment described above, in the grid interconnection apparatus 102, when the power supply device 110 is configured to output AC power, as in the second embodiment, DC / By providing an AC / DC converter (not shown) instead of the DC converter 120, the same effects as those of the grid interconnection system 101 according to the first embodiment can be obtained. In the grid interconnection system 101 having such a configuration, the AC / DC converter converts the output voltage output from the power supply device 110 into a DC voltage having a desired voltage value and outputs the DC voltage to the inverter 130. Further, the AC / DC converter outputs DC power to the general load Wb0 that is a DC load under the control of the control unit 140.

  As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

The whole schematic structure of the electric power system which concerns on this embodiment which concerns on 1st Embodiment of this invention is shown. It is a figure which shows the content of the power failure information which concerns on 1st Embodiment of this invention. It is a figure which shows the content of the power failure information which concerns on 1st Embodiment of this invention. It is a block diagram which shows the structure in the consumer which concerns on 1st Embodiment of this invention. It is a block block diagram of the control part which concerns on 1st Embodiment of this invention. It is a figure which shows the information memorize | stored in the memory | storage part which concerns on 1st Embodiment of this invention. It is a flowchart figure which shows operation | movement of the grid connection system which concerns on 1st Embodiment of this invention. It is a flowchart figure which shows operation | movement of the grid connection system which concerns on 1st Embodiment of this invention. In the grid connection system which concerns on 1st Embodiment, it is a timing chart at the time of a power failure generate | occur | producing in a self-distribution system and performing an "independent DC electric power driving | operation." In the grid connection system which concerns on 1st Embodiment, it is a timing chart at the time of a power failure generate | occur | producing in a self-distribution system and performing "self-supporting alternating current power operation". In the grid connection system which concerns on 1st Embodiment, it is a timing chart at the time of a power failure generate | occur | producing in another power distribution system, and performing "self-supporting alternating current power operation". It is a block diagram which shows the structure in the consumer which concerns on 2nd Embodiment of this invention.

Explanation of symbols

General loads Wb0 to Wb3, A to X ... distribution system, S11 to S23 ... step, S191 to S195 ... step, t0 to t3 ... time, ta to tb ... time, 1 ... substation, grid interconnection breaker CB, interconnection Relays Ry1 to Ry3, Relays Ry4, 10 ... Power failure management device, 15 ... Power transmission line, 16 ... Signal line, 100a to c ... Customer, 101 ... System interconnection system, 102 ... System interconnection device, 110 ... Power supply device 120 ... DC / DC converter, 120a ... AC / AC converter, 130 ... inverter, 140 ... control unit, 141 ... communication unit, 142 ... storage unit, 143 ... selection unit, 144 ... operation control unit

Claims (5)

A system interconnection device that converts electric power from a power supply device into predetermined AC power, and connects the power supply device to a distribution system to supply power to a load,
A receiving unit for receiving power outage information including power outage state information indicating a power outage state;
Based on the power outage state information, comprising an operation control unit that performs a self-sustaining operation that is disconnected from the power distribution system and supplies power to the load from the power supply device ,
The power outage state information is factor information indicating a cause of the power outage,
When the factor information included in the power outage information as the power outage state information is predetermined factor information, the operation control unit selects either the independent DC operation or the independent AC operation as the independent operation. apparatus. The power outage state information is power outage time information indicating a power outage time, and identification information of a distribution system in which the power outage has occurred,
The said operation control part performs the said independent operation, when the identification information of the said distribution system is the identification information of the said distribution system which is connected, and the said power failure time information is less than a predetermined threshold value. The grid interconnection device described in 1. The load is a plurality of loads with priorities,
3. The grid interconnection device according to claim 1 , wherein the operation control unit supplies power to a load having a high priority when performing the independent operation. The grid interconnection device according to claim 1, wherein the operation control unit supplies power to a specific load based on the identification information of the distribution system and the factor information. The grid connection system provided with the power supply device and the grid connection apparatus of any one of Claims 1 thru | or 4 .

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