JP2015080393A - Interconnection control device, and power generation/charging system including the control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interconnection control device capable of suppressing a large current from being flown when an operation of a power generation/charging system makes a transition to a system interconnection operation or an autonomous operation, and of shortening a time period in which no power is supplied to a self-sustaining load, and to provide a power generation/charging system including the control device.SOLUTION: An interconnection control device controls a power generation/charging system having: a plurality of distributed power supply devices each including a step-up circuit connected with a distributed power supply; and a system interconnection inverter converting a DC power outputted from the distributed power supply devices into an AC power, and outputting the AC power to at least one of a system load and a self-sustaining load. The interconnection control device, at a transition of the power generation/charging system to an autonomous operation or a system interconnection operation, restricts an output power of the system interconnection inverter to stop operations of the plurality of step-up circuits (a step S12). The interconnection control device, after a lapse of a restriction time period in which the output power of the inverter is restricted (a step S13), starts the operations of the plurality of step-up circuits (a step S14).

Description

  The present invention relates to an interconnection control device and a creation cooperation system including the control device.

  An example of a creation-saving cooperation system includes a distributed power source such as a solar cell, a storage battery, and a fuel cell, a power source switching unit, a grid interconnection inverter, and a grid control device. When the creation / storage cooperation system is in grid-connected operation, a distributed power source with a reverse power flow, such as a solar battery, is connected to the system power source via a grid-connected inverter. Is supplied to the system load and the independent load. On the other hand, when a voltage drop of the system power supply is detected, such as a power failure of the system power supply, the distributed power supply is disconnected from the system power supply, and the creation cooperation system starts independent operation. In this case, the power supplied from the distributed power supply is supplied to the self-supporting load.

JP 2000-92720 A

  According to the interconnection control device of Patent Document 1, when it is detected that the voltage of the system power supply has decreased, the system is switched from the grid interconnection operation to the independent operation in a short time. For this reason, the control for stopping the first inverter, the control for starting the second inverter, and the control for disconnecting the first inverter are executed at substantially the same timing. For this reason, an excessive transient current and an inrush current may flow through the second inverter due to the stop of the first inverter and the relationship between the disconnection timing of the first inverter and the start timing of the second inverter.

  On the other hand, as a configuration for reducing the transient current and the inrush current, for example, a configuration using a sequence type relay circuit as in the prior art in Patent Document 1 is conceivable. However, according to this configuration, as described in Patent Document 1, there is a possibility that the period during which power is not supplied to the self-supporting load becomes longer.

  An object of the present invention is to control interconnection that suppresses a large current from flowing when the operation of the creation cooperation system shifts to grid interconnection operation or autonomous operation, and shortens a period during which power is not supplied to the autonomous load. It is providing the creation-saving cooperation system containing an apparatus and this control apparatus.

  [1] An independent form of the interconnection control device includes the following matters. A distributed power supply, a plurality of distributed power supply devices including a booster circuit connected to the distributed power supply, DC power output from the distributed power supply device is converted into AC power, and the converted AC power is system load and independent load An inverter that outputs to at least one of the above, and an interconnection control device of a creation cooperation system that performs grid interconnection operation and autonomous operation with a grid power source, and when the transition to autonomous operation or grid interconnection operation, The output power of the inverter is limited, the operations of the plurality of booster circuits are stopped, and the operation of the plurality of booster circuits is started after a limit period, which is a time for stopping the operation of the booster circuit, has elapsed.

  [2] A form subordinate to the independent form of the interconnection control device includes the following matters. The interconnection control device maintains the boosted voltage in the power storage unit of the booster circuit when the operation of the booster circuit is stopped at the time of transition to the independent operation or the grid interconnection operation, and after the limit period has elapsed. Then, boosting is started including the charge stored in the power storage unit of the boosting circuit.

  [3] A form subordinate to the independent form of the interconnection control device includes the following matters. One of the plurality of distributed power supply devices is a power storage device, and the interconnection control device starts boosting the booster circuit including the charge stored in the power storage device after the limit period has elapsed. Let

  [4] A form subordinate to the independent form of the interconnection control device includes the following matters. The creation-saving cooperation system includes a power storage unit connected to a plurality of the booster circuits, and the inverter converts the DC power output from the power storage unit into AC power, and the converted AC power is always a self-supporting load. While outputting, the system power is also output to the system load at the time of system interconnection operation with the system power source, the connection form of the system power source and the inverter and the system load, and the system power source and the inverter and the independent load Based on a signal indicating a power failure or power recovery of the voltage of the system power supply, and a switching signal for switching between grid interconnection operation or independent operation is output to the power supply switching unit. After the voltage of the power storage unit reaches the reference voltage by the operation of the booster circuit, the restriction on the output power of the inverter is released.

  [5] A form subordinate to the independent form of the interconnection control device includes the following matters. The interconnection control device maintains the voltage of the power storage unit within a reference range, and releases the limit on the output power of the inverter after the limit period has elapsed.

  [6] A form subordinate to the independent form of the interconnection control device includes the following matters. One of the plurality of distributed power supply devices is the power storage device, and the interconnection control device supplies the output power of the power storage device to the independent load by outputting the switching signal to the power supply switching unit. .

  [7] A form subordinate to the independent form of the interconnection control device includes the following matters. Another one of the plurality of distributed power supply devices is a photovoltaic power generation device, and the interconnection control device outputs the switching signal to the power supply switching unit, thereby causing the photovoltaic power generation device to be connected to the system power supply. And the output power of the power storage device is supplied to the self-supporting load.

  [8] A form subordinate to the independent form of the interconnection control device includes the following matters. When the output power of the inverter is limited, the interconnection control device causes the solar power generation device to generate power and supplies the generated power to the power storage device.

  [9] An independent form of the present creation cooperation system includes the following matters. The interconnection control device described above is included.

  According to the interconnection control device and the creation cooperation system including the control device, it is suppressed that a large current flows when the operation of the creation cooperation system is shifted to the grid interconnection operation or the independent operation, and The period during which power is not supplied to the self-supporting load is shortened.

The block diagram of the creation cooperation system of 1st Embodiment. The interconnection independent automatic switching process flowchart of the creation cooperation system of 1st Embodiment. The time chart at the time of transfer to the self-sustained operation or grid connection operation of the creation cooperation system of 1st Embodiment. The time chart at the time of transfer to the self-sustained operation or grid connection operation of the creation cooperation system of 2nd Embodiment.

(First embodiment)
A first embodiment in which the above-described means are embodied will be described with reference to the block diagram of FIG. FIG. 2 is a configuration diagram of the creation cooperation system 10.

  The creation and cooperation system 10 includes a photovoltaic power generation device 20 as an energy creation system and a power storage device 30 as an energy storage system, and further includes a grid control device 60 and a system that is an inverter that converts DC power into AC power. The interconnection inverter 40 and the power supply switching unit 50 are provided. The solar power generation device 20 includes a solar battery 21 and a booster circuit 22 as a DC power source. The booster circuit 22 includes a first capacitor 23 as a power storage unit of the booster circuit. The power storage device 30 includes a storage battery 31 as an auxiliary power source and a bidirectional booster circuit 32. The bidirectional booster circuit 32 includes a second capacitor 33 as a power storage unit of the booster circuit.

  The output of the solar power generation device 20 and the output of the power storage device 30 are connected to the distributed power supply side common line 24 and supplied to the grid interconnection inverter 40. A large capacity third capacitor 12 as a power storage unit is connected to the distributed power supply side common line 24. As the storage battery 31, for example, a lead storage battery or a lithium ion battery is used. In the above example, the example using the distributed power source of the solar power generation device 20 and the power storage device 30 has been described. However, a three-cell cooperative system including a fuel cell device (not shown) may be used. .

The power supply switching unit 50 includes a connection switch 51, a self-supporting switch 52, and a connection self-supporting switching unit 53.
The grid interconnection inverter 40 has a grid output terminal 41 and a self-supporting output terminal 42. A grid output terminal 41 of the grid grid inverter 40 is connected to a grid power supply side power line 54 via a grid switch 51. The independent output terminal 42 of the grid interconnection inverter 40 is supplied to the interconnection independent switching unit 53 via the independent switch 52. The interconnection switch 51 and the self-supporting switch 52 are configured using, for example, semiconductor switches.

  The system load 13 is connected to the system power supply power line 54 to which the system power supply 11 that is a commercial power supply is connected. The interconnection independent switching unit 53 is connected to the system power supply side power line 54 and the independent switch 52 and to the independent load 14.

  Note that the interconnection control device 60 is configured using, for example, a DSP (Digital Signal Processor) which is a general-purpose signal processing device. The interconnection control device 60 is connected to the photovoltaic power generation device 20 and the power storage device 30, the grid interconnection inverter 40, and the power supply switching unit 50, which are distributed power sources, via the signal line 15, and sends control signals to each unit. Supply.

Next, based on the above configuration, the grid interconnection operation and the independent operation of the creation / cooperation system 10 will be described.
The booster circuit 22 of the solar power generation device 20 boosts the power generation voltage generated by the solar battery 21 and outputs it to the distributed power supply side common line 24. Similarly, the bidirectional booster circuit 32 of the power storage device 30 boosts the voltage of the power stored in the storage battery 31 and outputs it to the distributed power supply side common line 24. The bidirectional booster circuit 32 is configured to be able to supply the power generated by the solar battery 21 to the storage battery 31.

  When the grid connection operation with the system power supply 11 is performed, the creation cooperation system 10 switches the interconnection switch 51 into a conducting state and the self-contained switch 52 into a shut-off state based on control from the interconnection control device 60. Moreover, the interconnection independent switching part 53 is set to the grid interconnection operation state in which the system power supply power line 54 and the autonomous load 14 are electrically connected. For this reason, at the time of grid connection operation, the system power supply 11 is set in a state where the photovoltaic power generation apparatus 20 and the power storage apparatus 30 that are distributed power supplies are electrically connected. At the time of grid connection operation, the grid connection inverter 40 takes out power from both or either one of the solar power generation device 20 and the power storage device 30 and converts it into AC power synchronized with the system power supply 11. The grid interconnection inverter 40 supplies this AC power from the grid output terminal 41 to the grid load 13 via the grid switch 51. Further, the grid interconnection inverter 40 supplies AC power from the grid output terminal 41 to the self-supporting load 14 via the grid switch 51, the grid power supply side power line 54, and the grid independent switching unit 53. When the power supplied by either or both of the solar power generation device 20 and the power storage device 30 is insufficient, the system load 13 and the independent load 14 are supplied from the system power supply 11 via the system power supply side power line 54. To supply.

The interconnection control device 60 performs control for causing the creation cooperation system 10 to shift from the grid interconnection operation to the independent operation based on a signal indicating that the system power supply 11 has failed.
When the interconnection control device 60 shifts from the grid interconnection operation to the independent operation, the interconnection switch 51 is disconnected from the grid power supply side power line 54 by switching the interconnection switch 51 from the conductive state to the cutoff state. To do. That is, the interconnection control device 60 cuts off the electric power supplied to the grid load 13 from the output of both or one of the photovoltaic power generation device 20 and the power storage device 30 via the grid interconnection inverter 40. In addition, the interconnection control device 60 switches the interconnection independent switching unit 53 to the autonomous operation state in which the autonomous switch 52 and the autonomous load 14 are electrically connected, and the autonomous switch 52 is switched from the disconnected state to the conductive state. Switch to.

  Thus, the interconnection control device 60 switches the settings of the interconnection switch 51, the independent switch 52, and the interconnection independent switching unit 53 from the grid interconnection operation state to the autonomous operation state, thereby enabling the grid interconnection. A state in which power can be supplied from the inverter 40 to the self-supporting load 14 is set.

  In the independent operation, the grid interconnection inverter 40 takes out electric power from the power storage device 30 and converts it into AC power, and this AC power is independent from the independent output terminal 42 via the independent switch 52 and the interconnection independent switching unit 53. Supply to load 14. For this reason, the creation cooperation system 10 can supply electric power to the self-supporting load 14 even when the system power supply 11 fails.

  Based on a signal indicating that the grid power supply 11 has returned to power, the grid connection control device 60 performs control for causing the creation cooperation system 10 to shift from autonomous operation to grid interconnection operation. The interconnection control device 60 switches the interconnection switch 51, the autonomous switch 52, and the interconnection independent switching unit 53 of the power supply switching unit 50 that are in the independent operation setting state to the grid interconnection operation setting state. .

  The creation cooperation system 10 can shorten the period during which power is not supplied to the independent load 14 by switching the power supply switching unit 50 in a short period of time when shifting to the grid interconnection operation or the independent operation. For this reason, the interconnection control device 60 executes the switching of the interconnection switch 51, the self-standing switch 52, and the interconnection independent switching unit 53 at the same timing.

  When switching at the same timing is performed, the interconnection switch 51, the independent switch 52, and the interconnection independent switching unit 53 are set to the grid interconnection operation setting or the autonomous operation setting via the transient state. Switch. The transient state is a state that is different from both the grid connection operation setting and the independent operation setting, such as a state where the autonomous output terminal 42 of the grid interconnection inverter 40 is connected to the grid load 13 and the grid power supply 11. is there.

  Here, as a characteristic configuration of the first embodiment, the interconnection control device 60 stops the booster circuit 22, the bidirectional booster circuit 32, and the grid interconnection inverter 40, so that the grid interconnection inverter 40 The power switching unit 50 is switched while limiting the output power. Therefore, no matter what setting state the power supply switching unit 50 is in a transient state, the grid-connected inverter 40 is limited in current to be supplied. In the embodiment, since the grid interconnection inverter 40 is stopped, the supply of current is cut off.

  In addition, the interconnection control device 60 sets in advance the time for stopping the booster circuit 22 and the bidirectional booster circuit 32 as a limit period. The interconnection control device 60 starts the operations of the booster circuit 22 and the bidirectional booster circuit 32 after the limit period has elapsed. The interconnection control device 60 determines the voltage of the distributed power supply side common line 24 to which the outputs of the booster circuit 22 and the bidirectional booster circuit 32 are connected, and the voltage of the third capacitor connected to the distributed power supply side common line 24. Compare with reference voltage. After determining that the voltage of the third capacitor has reached the reference voltage, the interconnection control device 60 activates the grid interconnection inverter 40 to release the restriction on the output power. Therefore, in 1st Embodiment, it suppresses that a big electric current flows when the driving | operation of the creation-saving cooperation system 10 transfers to grid connection operation or independent operation, and electric power is not supplied to the independent load 14. FIG. The period can be shortened.

With reference to FIG. 2, each step is demonstrated in order about the interconnection independent operation automatic switching process.
The interconnection control device 60 executes this interconnection independent operation automatic switching process when the creation-saving cooperation system 10 is performing grid interconnection operation or autonomous operation.

  In step S11, the interconnection control device 60 determines whether a power failure or power recovery of the system power supply 11 has occurred. In step S11, the interconnection control device 60 repeats step S11 and continues the grid interconnection operation or the independent operation during a period in which it is determined that no power failure or power recovery of the grid power supply 11 has occurred.

  When the interconnection control device 60 determines in step S11 that a power failure or power recovery of the system power supply 11 has occurred, the interconnection controller 40, the booster circuit 22, and the bidirectional booster circuit 32 are stopped in step S12. Let For this reason, the grid interconnection inverter 40 is limited in output power. Moreover, the interconnection control device 60 switches the power supply switching unit 50 to the setting of the independent operation or the grid interconnection operation.

  In step S13, the interconnection control device 60 stands by until the time set as the limit period elapses. In step S <b> 14, the interconnection control device 60 activates the booster circuit 22 and the bidirectional booster circuit 32 to supply the boosted output to the third capacitor 12.

  In step S15, the interconnection control device 60 determines whether the voltage of the third capacitor 12, which is the input voltage of the grid interconnection inverter 40, has reached the reference voltage. The interconnection control device 60 repeats step S15 until the voltage of the third capacitor 12 reaches the reference voltage. When the interconnection control device 60 determines in step S15 that the voltage of the third capacitor 12 has reached the reference voltage, the interconnection control device 60 activates the grid interconnection inverter 40 in step S16, thereby releasing the restriction on the output power. .

  With reference to the time chart of FIG. 3, the operation | movement at the time of transfer to grid connection operation | movement or a self-sustained operation is demonstrated. In the description of FIG. 3, the case of shifting from grid interconnection operation to independent operation is described.

  When the power failure of the system power supply 11 is detected at time t1, the interconnection control device 60 stops the operation of the grid interconnection inverter 40, the booster circuit 22, and the bidirectional booster circuit 32. For this reason, the charge accumulated in the third capacitor 12 to which the outputs of the booster circuit 22 and the bidirectional booster circuit 32 are connected is discharged, and the voltage drops.

  The interconnection control device 60 supplies a control signal for switching from the setting of the grid interconnection operation to the setting of the autonomous operation to the interconnection switch 51, the independent switch 52, and the interconnection independent switching unit 53 at time t1. To do.

  The interconnection control device 60 sets the period from time t1 to time t2 as the limit period tSW. The power source switching unit 50 switches from the grid-connected operation setting to the independent operation setting during the limit period tSW. The length of the limit period tSW is set in consideration of the magnitude of the change width of the switching characteristics of the interconnecting switch 51, the self-supporting switch 52, and the interconnecting self-supporting switching unit 53.

  The interconnection control device 60 starts the operation of the bidirectional booster circuit 32 at time t2 when the limit period tSW elapses. For this reason, the potential of the third capacitor 12 gradually increases after time t2.

  The interconnection control device 60 activates the grid interconnection inverter 40 when detecting that the potential of the third capacitor 12 has reached the reference voltage at time t3. For this reason, the grid interconnection inverter 40 outputs the AC power with the restriction on the output power released at time t3.

  The interconnection control device 60 causes the photovoltaic power generation device 20 to generate power and supply the generated power to the power storage device 30 during a period in which the output power of the grid interconnection inverter 40 from time t1 to time t3 is limited.

In addition, also in the case where it shifts from a self-sustained operation to a grid interconnection operation, the interconnection control device 60 executes the same control as described above.
The creation / cooperation system 10 has the following effects.

  (1) The interconnection control device 60 stops the operation of the grid interconnection inverter 40, the booster circuit 22, and the bidirectional booster circuit 32 during the transition to the independent operation or the grid interconnection operation, and the grid interconnection inverter 40. Limit the output power of The interconnection control device 60 starts the operation of the booster circuit 22 and the booster circuit of the bidirectional booster circuit 32 after a limited period, which is the time for stopping the booster circuit 22 and the bidirectional booster circuit 32, has elapsed.

  According to this configuration, when the grid interconnection inverter 40 shifts to the independent operation or the grid interconnection operation, the load state of the grid interconnection inverter 40 connected to the interconnection output terminal 41 and the independent output terminal 42 is determined. Regardless, the output current is limited. For this reason, at the time of transition to a self-sustained operation or a grid-connected operation, the grid-connected inverter 40, the booster circuit 22, and the bidirectional booster circuit 32 are prevented from flowing a large current.

  (2) The creation-saving cooperation system 10 always outputs to the independent load, and also outputs to the grid load at the time of the grid interconnection operation with the grid power supply. The grid interconnection inverter 40, the grid load 13 and the independent load 14 Power supply switching unit 50 for switching the connection state between The interconnection control device 60 outputs a switching signal to the power supply switching unit 50 when shifting to the independent operation or the grid interconnection operation, and the output voltages of the booster circuit 22 and the bidirectional booster circuit 32 have reached the reference voltage. The restriction on the output current of the grid interconnection inverter 40 is released later.

  According to this configuration, the output current of the grid interconnection inverter 40 is limited regardless of the setting state of the power supply switching unit 50 during the transition to the independent operation or the grid interconnection operation. For this reason, the creation cooperation system 10 can switch the interconnection switch 51, the independent switch 52, and the interconnection independent switch unit 53 of the power supply switching unit 50 at the same timing. For this reason, the creation cooperation system 10 can shorten the period during which power is not supplied to the self-supporting load 14 at the time of transition to grid interconnection operation or self-sustained operation.

  (3) In the creation / cooperation system 10, one of the plurality of distributed power supply devices is the power storage device 30. The interconnection control device 60 supplies the output power of the power storage device 30 to the autonomous load by outputting a switching signal to the power supply switching unit 50 when the creation / cooperation system 10 is shifted from the grid interconnection operation to the autonomous operation. Let

  According to this structure, the electric power stored in the power storage device 30 can be supplied to the self-sustained load during the self-sustaining operation of the creation cooperation system 10. For this reason, the creation cooperation system 10 can supply stable electric power to the self-supporting load during the self-supporting operation.

  (4) In the creation cooperation system 10, another one of the plurality of distributed power supply devices is the solar power generation device 20. The interconnection control device 60 outputs the switching signal to the power supply switching unit 50, thereby disconnecting the photovoltaic power generation device 20 from the system power supply 11 and supplying the output power of the power storage device 30 to the self-supporting load 14.

  According to this configuration, the output power of the power storage device 30 is supplied to the self-supporting load 14 without using the power generated by the solar power generation device 20 during the self-sustained operation of the creation cooperation system 10. For this reason, the creation cooperation system 10 can supply more stable electric power to the self-supporting load during the self-supporting operation.

(5) When the output power of the grid interconnection inverter 40 is limited, the interconnection control device 60 causes the photovoltaic power generation device 20 to generate power and supplies the generated power to the power storage device 30.
According to this structure, the creation cooperation system 10 can efficiently use the electric power generated by the solar power generation device 20.

(6) The creation cooperation system 10 includes the interconnection control device 60 configured as described above.
According to this configuration, it is possible to obtain a creation-saving cooperation system that suppresses the flow of a large current when shifting to the grid interconnection operation or the self-sustained operation and shortens the period during which power is not supplied to the self-supporting load.

(Second Embodiment)
The creation cooperation system 10 of the second embodiment is different from the creation cooperation system 10 of the first embodiment in the following parts. The interconnection control device 60 in the creation cooperation system 10 of the first embodiment stops the operations of the booster circuit 22 and the bidirectional booster circuit 32 when the creation cooperation system 10 shifts to a self-sustained operation or a grid interconnection operation. As a result, the electric charge of the third capacitor is discharged and the voltage decreases. On the other hand, the interconnection control device 60 in the creation / cooperation system 10 of the second embodiment boosts the voltage when the booster circuit 22 and the bidirectional booster circuit 32 are stopped during the transition to the independent operation or the grid interconnection operation. Is maintained in the first capacitor 23 and the second capacitor 33.

With reference to FIG. 4, the operation | movement at the time of transfer to grid interconnection operation and self-sustained operation is demonstrated. In the description of FIG. 4, a case where a transition from grid interconnection operation to independent operation is described.
When the power failure of the system power supply 11 is detected at time t1, the interconnection control device 60 stops the operation of the grid interconnection inverter 40, the booster circuit 22, and the bidirectional booster circuit 32. For this reason, the grid interconnection inverter 40 stops the output. When the interconnection control device 60 stops the operations of the booster circuit 22 and the bidirectional booster circuit 32, the interconnection controller 60 holds the charges of the boosted voltage accumulated in the first capacitor 23 and the second capacitor 33. The interconnection control device 60 causes the first capacitor 23 and the second capacitor 33 to hold electric charges by interrupting the electric charge discharge path existing in the booster circuit 22 and the bidirectional booster circuit 32. The third capacitor 12 similarly holds the accumulated charge by interrupting the discharge path of the charges output from the booster circuit 22 and the bidirectional booster circuit 32.

  The interconnection control device 60 supplies a control signal for switching from the setting of the grid interconnection operation to the setting of the autonomous operation to the interconnection switch 51, the independent switch 52, and the interconnection independent switching unit 53 at time t1. To do.

  The interconnection control device 60 determines the voltage of the third capacitor 12 at time t2 when the limit period tSW has elapsed. The third capacitor 12 holds the voltage immediately before the operation of the booster circuit 22 and the bidirectional booster circuit 32 is stopped at time t1. For this reason, the interconnection control device 60 determines that the voltage of the third capacitor 12 has reached the reference voltage at time t2. For this reason, the interconnection control device 60 starts the operation of the grid interconnection inverter 40 and the bidirectional booster circuit 32 at time t2. The bidirectional booster circuit 32 starts the boosting operation including the charge accumulated in the second capacitor 33.

The grid interconnection inverter 40 starts operation at time t2, thereby releasing the restriction on the output power and outputting AC power.
In addition, also in the case where it shifts from a self-sustained operation to a grid interconnection operation, the interconnection control device 60 executes the same control as described above.

The creation cooperation system 10 has the same effects as (1) to (6) produced by the creation cooperation system 10 of the first embodiment. Moreover, the creation cooperation system 10 has the following effects.
(7) When the interconnection control device 60 stops the operation of the booster circuit 22 and the bidirectional booster circuit 32 during the transition to the independent operation or the grid interconnection operation, the booster circuit 22 accumulates the first capacitor 23. The step-up operation including the charged charge is started. Further, the bidirectional booster circuit 32 starts a boosting operation including the charge accumulated in the second capacitor 33.

  According to this configuration, the interconnection control device 60 can advance the timing at which the restriction on the output power of the grid interconnection inverter 40 is released at the time of shifting to the independent operation or the grid interconnection operation. For this reason, the creation cooperation system 10 can further shorten the period during which power is not supplied to the self-supporting load 14 when shifting to the self-sustained operation or the grid connection operation.

  (8) One of the plurality of distributed power supply devices is the power storage device 30, and the interconnection control device 60 includes the bidirectional booster circuit 32 including the charge stored in the power storage device 30 after the limit period has elapsed. Start boosting.

According to this configuration, the creation cooperation system 10 can perform voltage boosting using a stable voltage when shifting to a self-sustained operation or a grid interconnection operation.
(9) The interconnection control device 60 maintains the voltage of the third capacitor 12 in the reference range, and the grid interconnection inverter 40 has passed after a limit period, which is a period in which the booster circuit 22 and the bidirectional booster circuit 32 are stopped. Remove the output power limit for.

  According to this configuration, the creation cooperation system 10 has a large capacity to charge the output voltage when the operations of the booster circuit 22 and the bidirectional booster circuit 32 are stopped when shifting to the independent operation or the grid interconnection operation. The third capacitor 12 holds. For this reason, the voltage of the 3rd capacitor | condenser 12 when the operation | movement of the booster circuit 22 and the bidirectional | two-way booster circuit 32 is stopped at the time of transfer to a self-sustained operation or a grid connection operation is stabilized. For this reason, the creation cooperation system 10 can stabilize the operation | movement at the time of transfer to independent operation or grid connection operation.

(Other embodiments)
The present creation cooperation system includes other embodiments different from the first embodiment and the second embodiment. Other embodiment has the form as a modification of 1st Embodiment shown below and 2nd Embodiment as an example. Note that the following modifications can be combined with each other within a technically consistent range.

  The interconnection control device 60 of the first and second embodiments limits the output of the grid interconnection inverter 40 by stopping the grid interconnection inverter 40. However, the control of the interconnection control device 60 is not limited to the contents exemplified in the first and second embodiments. The interconnection control device 60 according to the modification limits the output by reducing the drive capability of the grid interconnection inverter 40.

  The interconnection control device 60 according to the first and second embodiments stops the grid interconnection inverter 40 during the limit period tSW, and the interconnection switch 51, the independent switch 52, and the interconnection independent switching unit 53. Is switched to the setting for independent operation. However, the control of the interconnection control device 60 is not limited to the contents exemplified in the first and second embodiments. The interconnection control device 60 of the modified example stops the grid interconnection inverter 40 and sets the interconnection switch 51, the independent switch 52, and the interconnection independent switching unit 53 for independent operation after a predetermined time has elapsed. Switch to.

  In the first and second embodiments, the interconnecting switch 51 and the self-supporting switch 52 are constituted by semiconductor switches. However, the configurations of the interconnecting switch 51 and the self-supporting switch 52 are not limited to the contents exemplified in the first and second embodiments. The system switch and the self-supporting switch of the modification are configured by relays.

  The interconnection control device 60 of the first and second embodiments is configured using a DSP. However, the configuration of the interconnection control device 60 is not limited to the contents exemplified in the first and second embodiments. The interconnection control device according to the modification is configured using a CPU.

  DESCRIPTION OF SYMBOLS 10 ... Creation cooperation system, 12, 3rd capacitor, 13 ... System load, 14 ... Self-supporting load, 20 ... Solar power generation device, 22 ... Booster circuit, 23 ... First capacitor, 30 ... Power storage device, 32 ... Bidirectional Step-up circuit 33... Second capacitor 40... Grid connection inverter 50.

Claims (9)

A distributed power supply, a plurality of distributed power supply devices including a booster circuit connected to the distributed power supply, DC power output from the distributed power supply device is converted into AC power, and the converted AC power is system load and independent load An inverter that outputs to at least one of the system, a grid connection control device of a creation-saving cooperation system that performs grid connection operation and independent operation with a grid power source,
After transition to independent operation or grid interconnection operation, the output power of the inverter is limited, the operations of the plurality of booster circuits are stopped, and the time limit for stopping the operation of the booster circuits has elapsed An interconnection control device that starts operation of the plurality of booster circuits.   The interconnection control device maintains the boosted voltage in the power storage unit of the booster circuit when the operation of the booster circuit is stopped at the time of transition to the independent operation or the grid interconnection operation, and after the limit period has elapsed. 2. The interconnection control device according to claim 1, wherein boosting is started including the charge stored in the power storage unit of the booster circuit.   One of the plurality of distributed power supply devices is a power storage device, and the interconnection control device starts boosting the booster circuit including the charge stored in the power storage device after the limit period has elapsed. The interconnection control device according to claim 1, wherein: The creation-saving cooperation system includes a power storage unit connected to a plurality of the booster circuits, and the inverter converts the DC power output from the power storage unit into AC power, and the converted AC power is always a self-supporting load. While outputting, also output to the system load in conjunction with the grid power supply operation,
A connection mode between the system power source and the inverter and the system load, and a power source switching unit that switches a connection mode between the system power source and the inverter and the independent load;
Based on a signal indicating a power failure or power recovery of the voltage of the system power supply, a switching signal for switching between grid interconnection operation or independent operation is output to the power supply switching unit,
The interconnection control according to any one of claims 1 to 3, wherein the limitation on the output power of the inverter is released after the voltage of the power storage unit reaches a reference voltage by the operation of the booster circuit. apparatus.   5. The interconnection control device according to claim 4, wherein the interconnection control device maintains the voltage of the power storage unit within a reference range and releases the restriction on the output power of the inverter after the restriction period has elapsed.   One of the plurality of distributed power supply devices is a power storage device, and the interconnection control device supplies the output power of the power storage device to the independent load by outputting the switching signal to the power supply switching unit. The interconnection control device according to claim 5.   Another one of the plurality of distributed power supply devices is a photovoltaic power generation device, and the interconnection control device outputs the switching signal to the power supply switching unit, thereby causing the photovoltaic power generation device to be connected to the system power supply. The interconnection control device according to claim 6, wherein the interconnection control device is disconnected from the power storage device and the output power of the power storage device is supplied to the independent load.   8. The interconnection control device according to claim 7, wherein when the output power of the inverter is limited, the interconnection control device causes the solar power generation device to generate power and supplies the generated power to the power storage device. System controller.   A creation cooperation system including the interconnection control device according to any one of claims 1 to 8.