JP2001016782A - System interconnecting inverter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the power consumption of a system interconnection inverter device by suppressing consumption of system power in a standby state. SOLUTION: When a voltage Vp of a solar battery 1 exceeds a stop voltage Vc, a control power source section 4 is actuated to supply electric power to a control circuit 3 as a drive source. When the circuit 3 confirms that the voltage Vp of the solar battery 1 is sufficient or the other inverter actuating condition than the state of a power system 7 is satisfied, the circuit 3 closes a system voltage detecting relay 10 and connects the system 7 to the circuit 3 via an insulating transformer 5 for monitor. When the circuit 3 confirms that the state of the system 7 satisfies the inverter actuating conditions, the circuit 3 actuates an inverter main circuit 2. When the voltage Vp of the solar battery 1 becomes insufficient, the circuit 3 suppresses the consumption of system power by the transformer 5 and a load connected to the secondary side of the transformer 5, by disconnecting the commercial system 7 from the transformer 5 and load by opening the system voltage detecting relay 10, even when the circuit 2 is in operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grid-connected inverter device that obtains power from a power supply source such as a DC power supply or a generator, and more particularly to a technique for saving power in a standby state.

[0002]

2. Description of the Related Art In a photovoltaic power generation system, DC power generated from a solar cell is converted into AC power of a commercial frequency by a grid-connected inverter, and this AC power is supplied to a domestic load connected to the commercial grid. In this system, surplus power flows backward to the commercial power system.

FIG. 8 shows a prior art of Japanese Patent Laid-Open No. 6-1974.
It is a block diagram which shows the electrical structure of the grid connection inverter apparatus disclosed by the 55th publication. In this case, solar cell 1
Is converted into AC power by the interconnection inverter 2 ′, and the AC power is converted into the insulation transformer 12 and the switch 1.
The connection protection device 15 is connected to the load 17 via the connection protection device 3, and the connection protection device 15 is further connected to the commercial system 7.
Driving power is supplied from the commercial system 7 to the interconnection protection device 15 via the switch 14. Although not shown, the interconnection inverter 2 ′ is provided from the commercial system 7.
Is supplied with driving power. The switches 13 and 14 are controlled to open and close at a predetermined time set by the time setting means 16.
Power is also supplied from the commercial system 7 to the switches 13 and 14 and the time setting means 16. The setting of the opening / closing time in the time setting means 16 is adjusted to the sunrise time or the sunset time, and the switch 1
If opening / closing control is performed on the switches 3 and 14, during the time period from the sunset time to the sunrise time, the power supply to the interconnection inverter 2 ', the insulation transformer 12, and the interconnection protection device 15 is cut off, Power is saved.

[0004] In the case of the grid-connected inverter device having the configuration shown in Fig. 8, power consumption supplied from the commercial system 7 in the standby state is large as described above. In the operating state, the power loss in the insulating transformer 12 is large. For this reason, the system shown in FIG. 8 has hardly been adopted in recent system interconnection inverters, and instead, a transformerless system and a high-frequency insulation system have become mainstream.

[0005] The above is an introduction of the history of technology development, but not the prior art itself of the present invention. In the following, the description of the prior art for the present invention proceeds. The system interconnection inverter device shown in FIG. 7 is a prior art for the present invention. The DC power of the solar cell 1 is
The power is converted into AC power of a commercial frequency by a system interconnection inverter 8 and connected to the commercial system 7. Grid-connected inverter 8
Is an inverter main circuit 2 for converting the DC power of the solar cell 1 into AC power of a commercial frequency, and an interconnection relay 6 for opening and closing the connection between the AC output terminal of the inverter main circuit 2 and the commercial system 7.
A control circuit 3 for performing gate control of a switching element in the inverter main circuit 2 and a control power supply unit 4 for receiving DC power from the solar cell 1 and supplying a constant voltage power to the control circuit 3
And a monitor insulating transformer 5 provided between the commercial system 7 and the control circuit 3, and the control unit 9 is configured by the control circuit 3 and the monitor insulating transformer 5.

[0006] The control power supply section 4 is activated by receiving a supply of DC power from the solar cell 1 and supplies drive power to the control circuit 3. In the control unit 9, the control circuit 3 controls the solar cell 1
To confirm whether there is a necessary voltage, and also to confirm that there is no abnormality in the system voltage and the system frequency by inputting the system voltage from the commercial system 7 through the monitor insulating transformer 5. Later, the interconnection relay 6 is closed, and the inverter main circuit 2 is activated. The control circuit 3 controls the gate of the switching element of the inverter main circuit 2 to perform synchronous control of the output current from the inverter main circuit 2 and the system voltage. The control circuit 3 performs automatic start / stop of the system interconnection inverter 8 and various interconnection protection controls in addition to this control.

Since the system voltage needs to be detected before closing the interconnection relay 6 as described above, the primary side of the monitoring isolation transformer 5 is connected to the commercial system 7 on the system side relative to the interconnection relay 6. They are connected.

In the configuration shown in FIG. 7, the input power of the control power supply unit 4 is supplied from the solar cell 1, but the commercial power system
There is also a system supplied from.

In the case of the system interconnection inverter device having the configuration shown in FIG. 7, a control power supply unit 4 for supplying power to a control circuit 3 for controlling the drive of the inverter main circuit 2 is supplied from the solar cell 1 by a direct current. Since the power is received, the power from the commercial system 7 is not consumed in these portions regardless of day and night.

From the above situation, at present,
The system interconnection inverter device of the type shown in FIG. 7 in which the system interconnection inverter 8 has a built-in interconnection protection function is mainly used.

[0011]

In the prior art system interconnection inverter device shown in FIG. 7, the monitoring isolation transformer 5 is located on the system side of the commercial system 7 with respect to the system interconnection relay 6 for the reasons described above. Must be connected. For this reason, in a standby state in which power is not supplied from the solar cell 1 at night or on a cloudy day, for example, a load (not shown) connected to the secondary side of the insulating transformer 5 for monitoring or an iron loss of the insulating transformer 5 for commercial use causes 7 is consumed, which is the power consumed by the commercial grid 7 of the grid-connected inverter device in the standby state.

The present invention has been made to solve the above-mentioned problem, and has as its object to minimize power consumption from the system side in a standby state.

[0013]

Means for Solving the Problems An inverter main circuit for converting DC power from a power supply source into AC power and connecting the AC power to a system according to the first invention according to the present invention for solving the above-mentioned problems, A system interconnection inverter device including a control circuit that controls the inverter main circuit by inputting a state of the power supply source and a state of the system using the DC power as a driving source for monitoring, It has a configuration. That is, an opening / closing means is inserted in a monitor system path for inputting the state of the system to the control circuit, and the state of the power supply source has a voltage higher than a required level suitable for driving the inverter main circuit. When the required condition is satisfied, the opening / closing means is closed, and when the required condition is not satisfied, the opening / closing means is opened. According to this configuration, the following operation is provided. That is, due to circumstances such as nighttime or cloudy weather, required conditions are not satisfied such that the state of the power supply source does not reach a voltage higher than a required level suitable for driving the inverter main circuit. When the power is not supplied from the system to the control circuit, the monitor power such as a monitor isolation transformer and the load connected thereto consume system power more than necessary as standby power. Nothing.

A system interconnection inverter device according to a second aspect of the present invention has the following configuration in the first aspect of the present invention. In other words, when the voltage Vp of the power supply source is smaller than the closing reference value V1 of the switching unit, which is set higher than the stop reference voltage Vs of the inverter main circuit and equal to or lower than the startup reference voltage Vo, the switching unit is opened. When the voltage Vp of the power supply source is equal to or higher than the close reference value V1, the opening / closing means is closed. According to this configuration, the following operation is provided. That is, even when the control circuit is inputting the DC power of the power supply source as the drive source, if the voltage Vp of the power supply source is smaller than the closed reference value V1, the inverter main circuit cannot perform the interconnection operation. Although it is stopped, in such a situation, the open / close means is opened and the power for monitoring is not supplied from the system to the control circuit. Is not consumed as standby power, so that more energy can be saved. If the closing reference value V1 of the opening / closing means is set to be equal to the starting reference voltage Vo of the inverter main circuit, the rise of the system interconnection inverter device becomes quick.

The system interconnection inverter device according to a third aspect of the present invention has the following configuration in the first and second aspects of the present invention. That is, when the voltage Vp of the power supply source becomes equal to or less than the open reference value V2 of the opening / closing means set to be equal to or less than the stop reference voltage Vs of the inverter main circuit, or the inverter main circuit shifts from the operation state to the stop state. The opening / closing means is sometimes opened. According to this configuration, the following operation is provided. That is, even when the control circuit is inputting the DC power of the power supply source as the drive source, if the voltage Vp of the power supply source is equal to or lower than the open reference value V2, the inverter main circuit cannot perform the interconnection operation. Although it is stopped, the inverter main circuit may be stopped due to some factors, but in such a situation, open the opening and closing means,
Since the power for monitoring is not supplied from the system to the control circuit, the time during which the system power is not consumed as standby power in the monitoring system such as the insulating transformer for monitoring and the load connected thereto becomes longer, and further energy saving is achieved. . In addition,
If the opening reference value V2 of the opening / closing means is set equal to the stop reference voltage Vs of the inverter main circuit, the opening / closing means is opened simultaneously with the stop of the inverter main circuit, so that further energy saving is achieved.

Since a drop is provided between the closing reference value V1 and the opening reference value V2 of the opening / closing means, chattering does not occur in the opening / closing operation of the opening / closing means, and the life of the opening / closing means is improved.

A system interconnection inverter device according to a fourth aspect of the present invention has the following configuration in the first to third aspects of the present invention. That is, the control circuit is configured to close the opening / closing means when an inverter start condition other than a system state is satisfied, and to start the inverter main circuit when the system state satisfies the inverter start condition. . According to this configuration, the following operation is provided. In other words, when the inverter is not in the standby condition because the start condition is not satisfied,
Even when the switching means is open and the control circuit is inputting the DC power of the power supply source as a driving source, the monitoring power is not supplied from the system to the control circuit. In such a monitor system and a load connected to the monitor system, the time during which system power is not consumed as standby power is prolonged, thereby further saving energy.

A system interconnection inverter device according to a fifth aspect of the present invention has the following configuration in the first to third aspects of the present invention. That is, the control circuit closes the opening / closing means when confirming that an inverter start condition other than the system state is satisfied, and further starts the inverter main circuit when the system state satisfies the inverter start condition, When the state does not satisfy the inverter start condition, the opening / closing means is opened, and after a predetermined time interval, it is configured to confirm again whether the inverter start condition other than the system state is satisfied. According to this configuration, the following operation is provided. That is, even if the switching means is once closed, if the system state does not satisfy the inverter starting condition, the switching means is opened again, so that the system power is used as the standby power in the monitoring system such as the monitoring isolation transformer and the load connected thereto. The time that is not consumed is further lengthened, and further energy saving is achieved. Further, since an interval is provided before reconfirmation, chattering does not occur in the opening / closing operation of the opening / closing means, and the life of the opening / closing means is improved.

A system interconnection inverter device according to a sixth aspect of the present invention has the following configuration in the first to fifth aspects of the present invention. That is, the opening / closing means is configured as a transfer contact type, one contact is connected to the system, and the other contact is connected to a relay test terminal. According to this configuration, the following operation is provided. That is, the relay test terminal is a terminal for testing whether or not the interconnection protection function of the inverter is operating normally when the system interconnection inverter device is installed. In the operation state after the test is completed, the relay test terminals are not used. By configuring the opening / closing means in the transfer contact system, the contact of the monitor system and the contact of the relay test terminal are shared, and the cost and space can be reduced by reducing the number of parts.

A system interconnection inverter device according to a seventh aspect of the present invention has the following configuration in the first to sixth aspects of the present invention. That is, the power supply source requires fuel to generate electric power, and has means for detecting a remaining fuel amount Mf of the power supply source. The opening / closing means is opened when it is small, and the opening / closing means is closed when the remaining amount Mf is equal to or more than the remaining amount lower limit M1. According to this configuration, when the remaining amount of the power supply source becomes smaller than the lower limit value, the opening / closing means is opened to disconnect the commercial system from the control circuit, so that the control circuit does not consume standby power.

The system interconnection inverter device according to an eighth aspect of the present invention has the following configuration according to the first aspect of the present invention. In other words, the switching means includes means for detecting the power Pp of the power supply source, wherein the power Pp of the power supply source is set higher than the stop reference power Ps of the inverter main circuit and equal to or lower than the start reference power Po. The opening / closing means is opened when the value is smaller than the closed reference value P1, and the opening / closing means is closed when the power Pp of the power supply source is equal to or more than the closed reference value P1. According to this configuration, when the power supply source is a power detection type, by detecting the power Pp of the power supply source,
When the electric power Pp is smaller than the closed reference value P1, the opening / closing means is open and the control circuit is disconnected from the commercial system.
The control circuit does not consume standby power.

A system interconnection inverter device according to a ninth aspect of the present invention has the following configuration in the eighth aspect of the present invention. That is, when the power (Pp) of the power supply source becomes equal to or less than the open reference value (P2) of the open / close means set to be equal to or less than the stop reference power (Ps) of the inverter main circuit, the open / close means is opened. It is configured. According to this configuration, when the power supply source is the power detection type, the power Pp is detected by detecting the power Pp of the power supply source, so that the power Pp is equal to the stop reference power P of the inverter main circuit.
When the opening / closing means is equal to or less than the open reference value P2 set to be equal to or less than s, the opening / closing means is open and the control circuit is disconnected from the commercial system, so that the control circuit does not consume standby power.

A system interconnection inverter device according to a tenth aspect of the present invention has the following configuration in the first to ninth aspects of the present invention. That is,
An opening / closing mode switching means for switching the opening / closing mode of the opening / closing means to manual opening / closing or automatic opening / closing. According to this configuration, the opening / closing mode switching unit can separate the opening / closing control of the opening / closing unit from the instruction of the control circuit, so that the opening / closing unit can be manually switched.

The above components of the present invention can be interpreted as follows. The term “system” generally refers to a commercial system, but is not limited to a commercial system, and is thus expressed as such. The “state of the power supply source” refers to power or voltage or current generated in the power supply source or other electric quantity or a general physical quantity related thereto. The same applies to “system status”. The "opening / closing means" may be any device such as a mechanical or electrical or electronic relay, switch, switch, or the like, as long as it switches between a state of transmitting an electric quantity and a state of shutting off. The symbols Vp, Vo,
Vs, V1, V2, Vc, Mf, M1, Pp, Po, P
For s, P1, and P2, the same as those in the embodiment described later are used, but it is not necessary to be restricted by the specific numerical values shown in the embodiment, and the interpretation can be made within a reasonable range. Shall be. Furthermore, the meaning of “characterized” in the claims is merely for the convenience of explanation, and the actual configuration of the grid-connected inverter device to which the present invention is applied has a special configuration. Should not be interpreted merely as meaning that it is prominently expressed. It should be noted that the wording is used for convenience of explanation in comparison with the related art.

[0025]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a system interconnection inverter device according to the present invention.

[First Embodiment] FIG. 1 is a block circuit diagram showing an electrical configuration of a system interconnection inverter device according to a first embodiment. As shown in FIG.
Is composed of an inverter main circuit 2, a control circuit 3, a control power supply unit 4, an interconnection relay 6, a monitoring insulating transformer 5, and a newly added system voltage detection relay 10. The control unit 9 is composed of the control circuit 3 and the insulating transformer 5 for monitoring. The output terminal of the solar cell 1 is connected to the inverter main circuit 2 and the control circuit 3 in the grid-connected inverter 8.
And each input terminal of the control power supply unit 4. The control power supply unit 4 receives the DC power from the solar cell 1 to generate a constant voltage, and supplies the constant voltage to the control circuit 3 as a drive source. A load (not shown) is connected to the secondary side of the insulating transformer 5 for monitoring.

The control circuit 3 includes a microcomputer and a D
It is configured to be controlled by an SP (Digital Signal Processor) or the like. Here, a microcomputer is used. When the control circuit 3 receives a supply of a constant voltage from the control power supply unit 4 as a drive source, the control circuit 3 starts the microcomputer. The control circuit 3 determines the voltage Vp of the solar cell 1. When the voltage Vp of the solar cell 1 is equal to or higher than the closed reference value V1 of the system voltage detection relay 10, the control circuit 3 closes the system voltage detection relay 10 and activates the inverter main circuit 2 in principle. ing. When the voltage Vp of the solar cell 1 is equal to or lower than the stop reference voltage Vs of the inverter main circuit 2, the control circuit 3
The inverter main circuit 2 is stopped and the system voltage detection relay 10 is opened. This will be described in detail later. The control circuit 3 also performs various interconnection protection controls of the system interconnection inverter 8. The control circuit 3 drives the inverter main circuit 2 by performing gate control of a switching element in the inverter main circuit 2.

The inverter main circuit 2 converts DC power from the solar cell 1 into AC power at a commercial frequency. The output terminal of the inverter main circuit 2 is connected to the commercial system 7 via the interconnection relay 6. A midway of the connection line between the commercial system 7 and the interconnection relay 6 and the primary side of the monitoring insulating transformer 5 in the control unit 9 are connected via a newly added system voltage detection relay 10. The secondary side of the monitor isolation transformer 5 is connected to the control circuit 3 as well as to a load (not shown).

The interconnection relay 6 is controlled to open and close based on a control signal from the control circuit 3.
The opening and closing of the system voltage detection relay 10 is controlled based on a control signal from the control circuit 3.

The system voltage of the commercial system 7 is input to the control circuit 3 via the system voltage detection relay 10 and the monitoring isolation transformer 5, and the control circuit 3 determines the output current of the inverter main circuit 2 and the system voltage based on the system voltage. It is configured to perform synchronous control with a voltage or to perform interconnection protection control.

Next, the operation of the system interconnection inverter of the first embodiment configured as described above will be described.

In the normal state, the inverter main circuit 2
Is in a stopped state, and the system voltage detection relay 10 is normally open. When the output voltage Vp of the solar cell 1 reaches a predetermined value (when the output voltage Vp exceeds the stop voltage Vc), the control power supply unit 4 starts up and starts supplying a constant voltage power to the control circuit 3. The microcomputer in the control circuit 3 starts operation by receiving a constant voltage power supply from the control power supply unit 4 and operates when the solar cell 1 has sufficient power and when the inverter main circuit 2 is started up in a system other than the system. By confirming that there is no abnormality, that is, that the inverter startup conditions other than the system state are satisfied, and that the relay coil of the system voltage detection relay 10 is energized,
Close 0. Then, by closing the system voltage detection relay 10, the system voltage is input from the commercial system 7 side, and it is confirmed that there is no abnormality in the system voltage and the system frequency, that is, that the system state satisfies the inverter starting condition. Then, the inverter main circuit 2 is started.

Next, the above operation will be described in detail with reference to the flowchart of FIG. Before the description, the starting reference voltage Vo and the stopping reference voltage Vs of the inverter main circuit 2 are described.
The magnitude relationship between the closed reference value V1 and the open reference value V2 of the system voltage detection relay 10 and the stop voltage Vc of the control power supply unit 4 will be described. The start reference voltage Vo is higher than the stop reference voltage Vs. Although the closed reference value V1 of the system voltage detection relay 10 is equal to or lower than the startup reference voltage Vo of the inverter main circuit 2, it is assumed here that V1 = Vo. The open reference value V2 of the system voltage detection relay 10 is equal to or lower than the stop reference voltage Vs of the inverter main circuit 2 and higher than the stop voltage Vc of the control power supply unit 4. Here, it is assumed that V2 = Vs. As an example of numerical values, V1 = Vo = 160V, V2 = Vs = 130
V and Vc = 80V. However, it is needless to say that such numerical values are merely examples and may be appropriately changed according to the specifications.

The CPU (Central Processing Unit) of the microcomputer determines whether or not the voltage Vp of the solar cell 1 read in step S101 is equal to or higher than the detection relay closing reference value V1. When Vp <V1, the process proceeds to step S201. When Vp ≧ V1, the process proceeds to step S102 to determine whether there is any abnormality in the inverter startup conditions other than the system state. For example, in the system interconnection inverter 8, whether there is any abnormality in the internal temperature,
Judge whether there is a failure such as a blown fuse. If an abnormality is found in the determination, the process proceeds to step S201. If there is no abnormality, the process proceeds to step S103, in which the control circuit 3 supplies a close control signal to the system voltage detection relay 10 to thereby provide the system voltage detection relay. Close 10. As a result, the system voltage of the commercial system 7 is taken into the control circuit 3 via the system voltage detection relay 10 and the monitoring insulating transformer 5.

Next, the process proceeds to step S104, in which the waveform of the taken system voltage is read, and it is determined whether there is any abnormality in the effective voltage and the frequency, that is, whether the system state satisfies the inverter starting condition. If there is an abnormality, the process proceeds to step S201.
Proceeding to 05, the control circuit 3 gives a close control signal to the interconnection relay 6, thereby closing the interconnection relay 6.
Next, the process proceeds to step S106, where the inverter
Start

The judgment in step S102 and the step S10
When the determination of No. 4 is negative, the process proceeds to step S201. This step S201 is a step to be processed immediately after the inverter main circuit 2 is stopped. That is, when the voltage Vp of the solar cell 1 becomes equal to or lower than the stop reference voltage Vs of the inverter main circuit 2, the inverter main circuit 2 is stopped and the interconnection relay 6 is opened, but immediately thereafter, the process proceeds to step S201. ing.

In step S201, it is determined whether or not the read voltage Vp of the solar cell 1 is equal to or lower than the detection relay open reference value V2. When Vp> V2, the process proceeds to step S101. However, when Vp ≦ V2, the process proceeds to step S202, in which the control circuit 3 provides an open control signal to the system voltage detection relay 10 to open the system voltage detection relay 10. . When V2 is set to Vs and the voltage Vp of the solar cell 1 is equal to or lower than the stop reference voltage Vs, the voltage Vp is equal to or lower than the detection relay open reference value V2, and the control circuit 3 stops the inverter main circuit 2. At the same time, the system voltage detection relay 10 is also opened, thereby minimizing the consumption of system power by the monitor isolation transformer 5 and the load connected to the secondary side thereof.

When the inverter main circuit 2 is stopped and the interconnection relay 6 is opened, it is also possible to immediately proceed to step S202 and open the system voltage detection relay 10 without going through the judgment in step S201. Is the way.

According to the above configuration, even when the control circuit 3 is inputting the DC power of the solar cell 1 as the drive source via the control power supply section 4, the voltage Vp of the solar cell 1 is maintained at the detection relay closing reference value. Unless V1 is reached, the inverter main circuit 2 is stopped without being able to perform the interconnection operation. However, in such a situation, the system voltage detection relay 10 is opened to monitor from the commercial system 7 to the control circuit 3. Is not supplied, the time during which the system power is not consumed as standby power in the monitoring insulating transformer 5 and the load connected to the secondary side of the transformer 5 becomes longer, thereby saving energy.

As described above, even when the control circuit 3 is inputting the DC power of the solar cell 1 as a drive source via the control power supply unit 4, the voltage Vp of the solar cell 1 is maintained at the detection relay open reference. If the value is equal to or less than the value V2, the inverter main circuit 2 is stopped without being able to perform the interconnection operation, and the inverter main circuit 2 may be stopped due to some factors. Voltage detection relay 1
When 0 is opened, the time during which the system power is not consumed as the standby power in the monitoring insulating transformer 5 and the load connected to the secondary side thereof is extended, thereby saving energy.

If V1 = Vo is set, if the voltage Vp of the solar cell 1 reaches the detection relay closing reference value V1 or more as long as there is no abnormality, the system voltage detection relay 1
The closing operation of 0 and the activation of the inverter main circuit 2 can be performed at the same time, and the inverter main circuit 2 quickly rises to a stable state. If V2 = Vs is set, the inverter main circuit 2 can be stopped and the system voltage detection relay 10 can be opened at the same time, and the monitoring isolation transformer 5 and the load connected to the secondary side thereof can be connected. Power consumption in the system can be minimized.

However, the present invention is not limited to this, and may be set so that Vo> V1 or Vs.
> V2.

Further, since a drop is provided between the detection relay closing reference value V1 and the detection relay opening reference value V2, chattering does not occur in the opening / closing operation of the system voltage detection relay 10, and the system voltage detection relay 10 The life is improved.

Further, a configuration as shown in FIG. 13 can be employed so that the system voltage detection relay 10 can be manually opened and closed. This is different from the inverter device shown in FIG. 1 in that an open / close mode switching means 21 for switching the open / close mode of the system voltage detection relay 10 to automatic open / close or manual open / close is newly provided. Normally, the open / close mode switching means 21 sets the open / close mode of the system voltage detection relay 10 to the automatic open / close mode, and the open / close control of the system voltage detection relay 10 is performed according to a command from the control circuit. For example, when it is necessary to forcibly disconnect the system voltage detection relay 10 from the commercial power system for maintenance and inspection of the inverter device, the switching mode of the system voltage detection relay 10 is switched to the manual switching mode by the switching mode switching means 21 so that the system voltage is detected manually. The relay 10 can be opened and closed.

[Second Embodiment] The configuration of a system interconnection inverter device according to a second embodiment is the same as that of the first embodiment shown in FIG. 1 except that the sequence of the microcomputer in the control circuit 3 is changed.

The sequence is shown in the flowchart of FIG. The sequence shown in FIG. 3 differs from the sequence shown in FIG. 2 in the following points. In other words, the process proceeds to step S104 to read the captured system voltage waveform and determine whether there is any abnormality in the effective voltage or frequency. That is, it is confirmed that the system state satisfies the inverter start-up condition. If there is, the process proceeds to step S107, and the system voltage detection relay 10 closed in step S103 is opened again. Then, the process proceeds to step S108, and after waiting (idling) for a predetermined time, the process returns to step S101.

The significance of the sequence shown in FIG. 3 will be described. FIG.
If the voltage Vp of the solar cell 1 does not fall below the detection relay opening reference value V2 even if there is an abnormality in the system voltage or the system frequency in step S104, the system voltage detection relay 10 is opened. Don't do that. Therefore, even when there is an abnormality, the system voltage is supplied to the monitor isolation transformer 5 via the system voltage detection relay 10, and the system power is consumed by the monitor insulation transformer 5 and the load connected to the secondary side thereof. Will continue.

On the other hand, according to the sequence of FIG. 3, when the inverter starting condition other than the system state is satisfied, the system voltage detection relay 10 is closed once, and the commercial power system 7 supplies the control circuit 3 with the monitoring power. When the system voltage and the system frequency are abnormal and the system state does not satisfy the inverter start-up condition, the system voltage detection relay 10 that has been closed is turned off. Since the monitor is immediately opened again, the time during which the system power is not consumed as the standby power in the monitor insulating transformer 5 and the load connected to the secondary side of the transformer 5 becomes longer, and further energy saving is achieved.

Since a predetermined time interval is provided by the idling in step S108 until reconfirmation in step S101, chattering does not occur in the opening / closing operation of the system voltage detection relay 10, and the life of the system voltage detection relay 10 is improved. .

[Third Embodiment] In a third embodiment, the position of the system voltage detection relay 10 is changed. FIG. 4 is a block circuit diagram showing an electrical configuration of the system interconnection inverter device according to the third embodiment. The same reference numerals as those in FIG. 1 for the first embodiment indicate the same components in FIG. 4 for the third embodiment. Briefly, 1 is a solar cell, 2 is an inverter main circuit, 3 is a control circuit, 4 is a control power supply unit, 5 is an insulation transformer for monitoring, 6 is an interconnection relay, 7 is a commercial system, 8 is a system interconnection inverter,
Reference numeral 9 denotes a control unit, which is the same as described above unless otherwise specified, so that detailed description is omitted here. In addition, matters that have been described in the first embodiment and that are not described again in the present embodiment also apply to the present embodiment as they are, and detailed descriptions thereof will be omitted. The difference between the third embodiment and the first embodiment is as follows.

That is, the system voltage detection relay 10 is inserted into a common line portion between the connection line between the commercial system 7 and the interconnection relay 6 and the connection line between the commercial system 7 and the primary side of the monitor insulating transformer 5. It is.

In the third embodiment, the sequence of the microcomputer in the control circuit 3 is shown in FIG.
Can be used as is. Further, the sequence of FIG. 3 may be used as it is.

The operation of the system interconnection inverter device of the third embodiment is the same as that of the first embodiment when using the sequence shown in FIG. 2, and is executed when the sequence shown in FIG. 3 is used. Since it is the same as the case of the second embodiment, the description is omitted. The same effects and effects can be obtained.

[Fourth Embodiment] FIG. 5 is a block circuit diagram showing an electrical configuration of a system interconnection inverter device according to a fourth embodiment. The fourth embodiment differs from the first embodiment in FIG. 1 in that the system voltage detection relay 10 is controlled by:
A control power supply unit 4 is used instead of the control circuit 3.
The same reference numerals as those in FIG. 1 of the first embodiment indicate the same components in FIG. 5 of the fourth embodiment, and as described above, unless the coupling relationship between them is particularly specified. Therefore, detailed description is omitted here. In addition, matters that have been described in the first embodiment and that are not described again in the present embodiment also apply to the present embodiment as they are, and detailed descriptions thereof will be omitted. The configuration of the fourth embodiment is different from that of the first embodiment as follows.

That is, a control signal for opening and closing the relay is transmitted from the control power supply unit 4 to the system voltage detection relay 10. The system voltage detection relay 10 is interposed between the commercial system 7 and the primary side of the insulating transformer 5 for monitoring. When the voltage of the solar cell 1 becomes equal to or higher than a predetermined voltage, the control power supply unit 4 supplies a constant-voltage DC power to the control circuit 3 as a drive source. A signal is given, and the system voltage detection relay 10 is closed. Also,
When the voltage of the solar cell 1 becomes lower than the predetermined voltage, the supply of the DC power to the control circuit 3 is stopped.
At this time, the system voltage detection relay 10 is opened at the same time.

According to the fourth embodiment, the first to the first embodiments
It is not necessary to control the opening and closing of the system voltage detection relay 10 under various conditions by the sequence processing by the microcomputer as in the case of 3, and the operation is extremely simple. Can be.

Other operations are the same as those in the first embodiment, and a description thereof will not be repeated. The same effects and effects can be obtained.

[Fifth Embodiment] FIG. 6 is a block circuit diagram showing an electrical configuration of a system interconnection inverter device according to a fifth embodiment. The fifth embodiment is different from the first embodiment in FIG. 1 in that the system voltage detection relay 10 is changed to a transfer contact type (two-contact type). The same reference numerals as in FIG. 1 of the first embodiment denote the same components in FIG. 6 of the fifth embodiment, and the connection relationship between them is as described above unless otherwise specified. Therefore, detailed description is omitted here. In addition, matters that have been described in the first embodiment and that are not described again in the present embodiment also apply to the present embodiment as they are, and detailed descriptions thereof will be omitted. The configuration of the fifth embodiment is different from that of the first embodiment as follows.

That is, a transfer contact type (two contact type) is used as the system voltage detection relay 10 inserted between the commercial system 7 and the primary side of the insulating transformer 5 for monitoring. The c contact (common terminal) is connected to the primary side of the insulating transformer 5 for monitoring, the a contact is connected to the commercial system 7 side, and the b contact is connected to the relay test terminal 11 side.

The relay test terminal 11 is a terminal for testing whether or not the interconnection protection function of the inverter is working normally when the system interconnection inverter device is installed. The interconnection protection functions include, for example, system overvoltage,
There is a function to open the interconnection relay 6 when a system voltage shortage, a system frequency rise or fall, or the like occurs. At the time of the test, a simulated voltage is applied to the relay test terminal 11 from the control circuit 3 via the monitoring insulation transformer 5 and the contact b of the transfer contact type system voltage detection relay 10.

In the actual operation state after the system interconnection inverter device is installed and the test is completed, the relay test terminals 11
Simulated voltage is not applied to the control circuit 3 from the control circuit 3. Regarding the operation of the grid-connected inverter device in the actual operation state, when the control circuit 3 gives a closed control signal to the grid voltage detection relay 10, the grid voltage detection relay 10 is connected to the contact a, The commercial system 7 is connected to the primary side of the monitoring insulation transformer 5 via the system voltage detection relay 10. When the control circuit 3 gives an open control signal to the system voltage detection relay 10,
Although the system voltage detection relay 10 is connected to the contact b side, no special operation occurs.

In the fifth embodiment, the sequence of the microcomputer in the control circuit 3 is shown in FIG.
Can be used as is. Further, the sequence of FIG. 3 may be used as it is. Embodiment 5
The operation of the system interconnection inverter device is the same as that of the first embodiment when the sequence of FIG. 2 is used, and the same as that of the second embodiment when the sequence of FIG. 3 is used. Since there is, description is omitted. The same effects and effects can be obtained.

Further, in the fifth embodiment, the system voltage detection relay 10 is configured as a transfer contact type, so that a switch means for switching connection between the commercial system 7 and the monitor isolation transformer 5 and a relay Since the switch is also used as a switch for operating the test terminal 11, cost reduction and space saving can be achieved by reducing the number of components.

[Sixth Embodiment] FIG. 9 is a block circuit diagram showing an electrical configuration of a system interconnection inverter device according to a sixth embodiment. Embodiment 6 is different from Embodiment 1 in FIG. 1 in that the solar cell 1 is replaced with a fuel cell 18,
A fuel remaining amount detecting means 19 is newly provided. The same reference numerals as those in FIG. 1 of the first embodiment indicate the same components in FIG. 9 of the sixth embodiment, and as described above, unless otherwise specified. Therefore, detailed description is omitted here. In addition, matters that have been described in the first embodiment and that are not described again in the present embodiment also apply to the present embodiment as they are, and detailed descriptions thereof will be omitted. The configuration of the sixth embodiment differs from that of the first embodiment in the following points.

That is, the DC power of the fuel cell 18 is converted into AC power of a commercial frequency by the system interconnection inverter 8 and connected to the commercial system 7. Fuel remaining amount detecting means 19
Detects the remaining amount of fuel in the fuel cell 18 and sends the detected value to the control circuit 3. The control circuit 3 determines that the fuel cell 18 has sufficient power when the inverter performs the system interconnection operation by inputting the voltage of the fuel cell 18, that the detected fuel remaining amount is equal to or greater than a predetermined value, After confirming that there is no abnormality in starting the inverter, the system voltage detection relay 10 is closed.

For example, the control circuit 3 controls opening and closing of the system voltage detection relay 10 according to the sequence shown in the flowchart of FIG. The control circuit receives power supply from the control power supply 4 and the microcomputer starts to start. At this time, in the initial state, the system voltage detection relay 10 is in an open state, and the inverter is in a stopped state. When the microcomputer is started, first, the microcomputer executes step S301, reads the remaining fuel value Mf of the fuel cell, and compares it with the lower fuel limit M1. If Mf <M1, step S
Proceed to 402. If Mf ≧ M1, the process proceeds to step S302, where the fuel cell voltage Vp is read and compared with the system voltage detection relay closing reference value V1. Here, this closed reference value V1
Are the same as in the first embodiment. If Vp <V1, the process proceeds to step S401. Vp ≧
If it is V1, the process proceeds to step S303, and the inverter starting conditions other than the system conditions are confirmed. If there is an abnormality, the process proceeds to step S401. If there is no abnormality, step S304.
In, the system voltage detection relay 10 is closed, and the process proceeds to step S305. In step S305, the system voltage waveform is read via the system voltage detection relay 10, and it is confirmed whether the effective voltage and the frequency are within normal ranges. Then, the interconnection relay 6 is closed, and the inverter is started in step S307.

Next, when the inverter is stopped, step S401 is executed. In step S401, the fuel cell voltage Vp is read and compared with the system voltage detection relay opening reference value V2. Here, the setting of the open reference value V2 is the same as in the first embodiment. If Vp ≦ V2, the process proceeds to step S402 and the system voltage detection relay 10
Is output, and the process returns to step S401. On the other hand, if Vp> V2, the process proceeds to step S301. Also, as in the first embodiment, it is a good method to open the system voltage detection relay 10 whenever the inverter shifts from the operation state to the stop state.

As in the sequence of FIG. 3 of the first embodiment, if an abnormality is detected in the system state in step S305 of the flowchart of FIG. By providing a step of returning to S301, power consumption from the grid can be further reduced.

Further, similarly to FIG. 4 of the third embodiment, the following changes can be made to the configuration of FIG. 9 of the sixth embodiment. That is, the system voltage detection relay 10
May be installed between the interconnection relay 6 and the commercial system 7, and the system line between the interconnection relay 6 and the system voltage detection relay 10 may be connected to the transformer 5 in the control unit 9. .

Further, similarly to FIG. 5 of the fourth embodiment, the following changes can be made to the configuration of FIG. 9 of the sixth embodiment. That is, the control power supply 4 is configured to open and close the system voltage detection relay 10. The control power supply 4 starts supplying power to the control circuit 3 when the fuel cell 18 has a voltage equal to or higher than a predetermined voltage.
A voltage is also applied to the relay coil of 0, and the system voltage detection relay 10 is closed. When the voltage of the fuel cell 18 falls below a predetermined voltage, the control circuit 3 and the system voltage detection relay 10
Power supply to the power supply is stopped.

As in FIG. 6 of the fifth embodiment, the following changes can be made to the configuration of FIG. 9 of the sixth embodiment. That is, the system voltage detection relay 10 is a two-contact (a, b) changeover switch, and the contact a is connected to the commercial system 7 and the contact b is connected to the relay test terminal 11. In the description of the sixth embodiment, when the system voltage detection relay 10 is closed, it is connected to the contact a, and when the system voltage detection relay 10 is opened, it is connected to the contact b.

[Seventh Embodiment] FIG. 11 is a block circuit diagram showing an electrical configuration of a system interconnection inverter device according to a seventh embodiment. The seventh embodiment differs from the first embodiment in FIG. 1 in that a power detection unit 20 is provided between the solar cell 1 and the inverter circuit 2. The same reference numerals as those in FIG. 1 for Embodiment 1 indicate the same components in FIG. 11 for Embodiment 7;
Unless otherwise specified, the connection relationship between them is the same as described above, and the detailed description is omitted here. In addition, matters that have been described in the first embodiment and that are not described again in the present embodiment also apply to the present embodiment as they are, and detailed descriptions thereof will be omitted. The configuration of the seventh embodiment differs from that of the first embodiment in the following.

That is, the control circuit 3 detects the power generated by the solar cell 1 via the power detecting means 20 and determines whether there is sufficient power in the solar cell 1 when the inverter performs the system interconnection operation. After confirming that there is no abnormality in starting the inverter other than the above, the system voltage detection relay 10 is closed. For example, as a method of detecting power during a period when the inverter is not performing the system interconnection operation, a resistor is connected to the solar cell 1 only during the period, a current value flowing through the resistor is detected by a current sensor, and a solar cell output is detected. There is a method of calculating the product of the voltage and the solar cell power. During the period when the inverter performs the system interconnection operation, the power detection by the resistance leads to a decrease in the efficiency of the inverter.
And the power is calculated in the same manner.

For example, the control circuit 3 operates according to the sequence shown in the flowchart of FIG.
Control the opening and closing of zero. This corresponds to steps S101 and S2 in the flowchart of FIG.
Only the determination condition of 01 is changed. In the initial state, the system voltage detection relay 10 is open, and the inverter is in a stopped state. When the microcomputer is started by receiving power supply from the control power supply 4, the control circuit 3 first executes step S501, reads the power Pp of the solar cell, and compares it with the system voltage detection relay closing reference value P1. The closing reference value P1 is set to a value lower than the starting reference power Po of the inverter and larger than the stopping reference power Ps. Here, it is assumed that P1 = Po. Then, as a result of the comparison, if the solar cell power Pp is low, the process proceeds to step S502, and the subsequent processing is the same as in the first embodiment. If the inverter has been stopped, step S502 is executed. In step S502, the solar cell power Pp is compared with the system voltage detection relay opening reference value P2. The open reference value P2 is equal to or less than the inverter stop reference power Ps, and the stop power P
Although it is set to a value higher than c, in order to reduce power consumption from the grid as much as possible, P2 = Ps is set, and the grid voltage detection relay 10 is opened at the same time when the inverter is stopped. The processing after step S502 is the same as in the first embodiment.

While some embodiments have been described above, the present invention can include the following configurations. (1) As a modification of the third embodiment (FIG. 4), a system interconnection inverter device having a circuit configuration in which the interconnection relay 6 is omitted may be configured. (2) As a modification of the fourth embodiment (FIG. 5), the arrangement position of the system voltage detection relay 10 is changed to the third embodiment (FIG. 4).
May be the same as in the case of. (3) As a modification of the fifth embodiment (FIG. 6), the arrangement position of the system voltage detection relay 10 is changed to the third embodiment.
As in the case of FIG. 4, the connection line between the commercial system 7 and the interconnection relay 6, the commercial system 7 and the monitor isolation transformer 5 are connected.
May be configured such that a transfer contact type system voltage detection relay 10 is interposed in a common line portion with a connection line with the primary side. (4) In accordance with the method of the fourth embodiment (FIG. 5), the control power supply unit 4 supplies the system voltage detection relay 10 from the control power supply unit 4 regardless of the position of the transfer contact type system voltage detection relay 10 inserted above. 10 may be configured to control opening and closing. (5) For any other items that are not directly related to the gist of the present invention, any well-known ones can be applied. It goes without saying that it is applicable.

The above items (1) to (5) are independent from each other, and any number of these items may be appropriately combined.

In the specification (particularly, the detailed description of the invention and the claims) or the drawings relating to the present case, any matters described (including any elements or a connection relation / combination relation of any elements) are described. Reserves the possibility of omitting it. Furthermore, the possibility of adding any matter not described in the claims but described in the detailed description of the invention or in the drawings to the claims and the possibility of changing the description accompanying the additions is described. Reserve

[0078]

According to the first invention of the system interconnection inverter device, the opening / closing means is inserted in the path for monitoring and inputting the state of the system to the control circuit so that the state of the solar cell can satisfy the required condition. When not satisfied, the opening / closing means is configured to be opened, so the state of the solar cell is insufficient to drive the inverter main circuit due to circumstances such as nighttime or cloudy weather, and the standby state Is satisfied, the monitor system and the load connected thereto do not consume system power more than necessary, and energy can be saved.

According to the second aspect of the present invention, as long as the voltage Vp of the solar cell does not reach the closing reference value V1 of the opening / closing means, the opening / closing means is opened to supply power for monitoring from the system to the control circuit. Therefore, even when the control circuit is inputting the DC power of the solar cell as a drive source, the monitoring system such as the monitoring isolation transformer and the load connected to it do not consume the system power as standby power for a long time. Therefore, further energy saving can be achieved.

According to the third aspect of the present invention, when the voltage Vp of the solar cell is equal to or lower than the open reference value V2 and when the inverter main circuit is stopped for some reason, the opening / closing means is opened. Therefore, power for monitoring is not supplied from the system to the control circuit, so even when the control circuit is inputting the DC power of the solar cell as a drive source, the monitor system such as a monitor isolation transformer and the connection to it are not provided. With this load, the time during which system power is not consumed as standby power becomes longer, and further energy saving can be achieved.

According to the fourth aspect of the present invention, when the inverter is in a standby state because the inverter starting conditions are not satisfied, the opening / closing means is opened to supply the monitoring power from the system to the control circuit. Therefore, even when the control circuit is inputting the DC power of the solar cell as a driving source, the time during which the system power is not consumed as standby power by the monitor system and the load connected thereto becomes longer, and further energy saving is achieved. Can be planned.

According to the fifth aspect of the present invention, even if the opening / closing means is once closed, if the system state does not satisfy the inverter starting condition, the opening / closing means is opened again. The time during which system power is not consumed as standby power is further increased, and further energy savings can be achieved. Further, since an interval is provided before the reconfirmation, chattering does not occur in the opening / closing operation of the opening / closing means, and the life of the opening / closing means can be improved.

According to the sixth aspect of the present invention, since the opening / closing means is of a transfer contact type and serves as both a monitor system contact and a relay test terminal contact, cost reduction and cost saving can be achieved by reducing the number of parts. Space can be provided.

According to the seventh aspect of the present invention, when the remaining amount of the power supply source becomes smaller than the lower limit, the opening / closing means is opened and the commercial system is disconnected from the control circuit. I can't.

According to the eighth aspect of the present invention, when the power supply source is of the power detection type, by detecting the power Pp of the power supply source, as long as the power Pp does not reach the closed reference value P1, it is opened and closed. Since the means is open and the control circuit is disconnected from the commercial system, the control circuit does not consume standby power.

According to the ninth aspect of the present invention, when the power supply is of the power detection type, the power Pp is set to be equal to or less than the stop reference power Ps of the inverter main circuit by detecting the power Pp of the power supply. Open reference value P of the opening / closing means
When the value is 2 or less, the opening / closing means is open and the commercial system is disconnected from the control circuit, so that the control circuit does not consume standby power.

According to the tenth aspect of the present invention, since the opening / closing means can be manually opened / closed, for example, when performing maintenance and inspection of the apparatus, the monitoring system such as a monitoring insulation transformer and the load connected thereto are connected to the commercial system. Can be safely inspected in a completely disconnected state.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram showing an electrical configuration of a system interconnection inverter device according to a first embodiment of the present invention;

FIG. 2 is a flowchart illustrating the operation of the system interconnection inverter device according to the first embodiment;

FIG. 3 is a flowchart for explaining the operation of the system interconnection inverter device according to the second embodiment;

FIG. 4 is a block circuit diagram illustrating an electrical configuration of a grid-connected inverter device according to a third embodiment;

FIG. 5 is a block circuit diagram showing an electrical configuration of a grid-connected inverter device according to a fourth embodiment;

FIG. 6 is a block circuit diagram illustrating an electrical configuration of a grid-connected inverter device according to a fifth embodiment;

FIG. 7 is a block circuit diagram showing an electrical configuration of a conventional system interconnection inverter device.

FIG. 8 is a block diagram showing an electrical configuration of a conventional type grid-connected inverter device.

FIG. 9 is a block circuit diagram showing an electrical configuration of a system interconnection inverter device according to a sixth embodiment;

FIG. 10 is a flowchart for explaining the operation of the system interconnection inverter device according to the sixth embodiment;

FIG. 11 is a block circuit diagram showing an electrical configuration of a system interconnection inverter device according to a seventh embodiment;

FIG. 12 is a flowchart illustrating the operation of the system interconnection inverter device according to the seventh embodiment;

FIG. 13 is a block circuit diagram showing an electrical configuration of another system interconnection inverter device according to the first embodiment of the present invention;

[Explanation of symbols]

1: solar cell, 2: inverter main circuit, 3: control circuit,
4 ... Control power supply unit, 5 ... Monitoring isolation transformer, 6 ... Connection relay, 7 ... Commercial system, 8 ... System connection inverter, 9 ...
Control unit, 10: system voltage detection relay, 11: relay test terminal, 18: fuel cell, 19: fuel remaining amount detection means, 2
0: power detection means, 21: open / close mode switching means

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5F051 BA11 KA03 KA07 5G066 HA04 HA06 HA30 HB06 5H007 AA05 BB07 CC09 DA04 DB01 DB12 DC03 DC05 FA19 GA01

Claims (10)

[Claims] 1. An inverter main circuit for converting DC power from a power supply source to AC power and connecting the AC power to a system, and inputting a state of the power supply source and a state of the system using the DC power as a drive source. A system interconnection inverter device including a control circuit for controlling the inverter main circuit, wherein an opening / closing unit is inserted in a path for inputting a state of the system to the control circuit, and a state of the power supply source is required. A system interconnection inverter device configured to close the opening / closing means when a condition is satisfied and open the opening / closing means when the condition is not satisfied. 2. A closing reference value (V1) of the switching means, wherein a voltage (Vp) of the power supply source is set higher than a stop reference voltage (Vs) of the inverter main circuit and equal to or lower than a start reference voltage (Vo). If the voltage is smaller than the reference voltage (Vp), the voltage (Vp) of the power supply source is closed.
1) The system interconnection inverter device according to claim 1, wherein the opening / closing means is closed in the above cases. 3. When the voltage (Vp) of the power supply source becomes equal to or less than an open reference value (V2) of the switching means which is set to be equal to or less than a stop reference voltage (Vs) of the inverter main circuit, or the inverter main circuit. 3. The system interconnection inverter device according to claim 1, wherein the switching device is configured to open the opening / closing means when the device shifts from an operation state to a stop state. 4. 4. The control circuit closes the opening / closing means when an inverter start condition other than a system state is satisfied,
The system interconnection inverter device according to any one of claims 1 to 3, wherein the inverter main circuit is configured to be activated when a system state satisfies an inverter activation condition. 5. The control circuit closes the opening / closing means when confirming that an inverter start condition other than a system state is satisfied, and starts the inverter main circuit when the system state satisfies the inverter start condition. When the system state does not satisfy the inverter start condition, the opening / closing means is opened, and after a predetermined time interval, it is configured to reconfirm whether the inverter start condition other than the system state is satisfied. The system interconnection inverter device according to any one of claims 1 to 3, wherein: 6. The switch according to claim 1, wherein said switching means is of a transfer contact type, one contact is connected to said system, and the other contact is connected to a relay test terminal. 5. The grid-connected inverter device according to any one of 5). 7. The power supply source requires fuel to generate electric power, and the remaining amount of fuel of the power supply source (M
f), and when the remaining amount (Mf) of the fuel is smaller than the lower limit (M1), the opening / closing means is opened, and the remaining amount (Mf) is lower than the lower limit (Mf). The system interconnection inverter device according to any one of claims 1 to 6, wherein the opening / closing means is configured to be closed in the case of M1) or more. 8. A power supply (Pp) for detecting the power (Pp) of the power supply source, wherein the power (Pp) of the power supply source is higher than a stop reference power (Ps) of the inverter main circuit and a start reference power (Ps). Po) If the opening / closing means is smaller than the closing reference value (P1) which is set to be equal to or less than the opening / closing means, the opening / closing means is opened, and the power (Pp) of the power supply source is reduced to the closing reference value (P1).
1) The system interconnection inverter device according to claim 1, wherein the opening / closing means is closed in the above cases. 9. When the power (Pp) of the power supply source becomes equal to or less than an open reference value (P2) of the open / close means set to be equal to or less than a stop reference power (Ps) of the inverter main circuit, The system interconnection inverter device according to claim 8, wherein the system interconnection device is configured to be opened. 10. The grid-connected inverter device according to claim 1, further comprising an open / close mode switching unit that switches an open / close mode of the open / close unit to manual open / close or automatic open / close.