JP2016082732A - Sequence re-interconnection device and sequence re-interconnection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To implement sequence re-interconnection under remote control on the condition that an inverse load flow problem does not occur, after a power failure of a sequence.SOLUTION: A sequence re-interconnection device comprises: power failure detection means 120 which detects the power failure of the sequence; control means 140 which short-circuits a pair of external abnormal stop terminals provided in a power conditioner connected to a solar panel when the power failure is detected by the power failure detection means 120; communication means 130 which receives a re-interconnection instruction transmitted after recovery of the sequence; and control means 140 which releases the external abnormal stop terminals in accordance with the re-interconnection instruction received by the communication means 130.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a system reconnection apparatus and a system reconnection system, and in particular, reconnects a target such as a power conditioner that is electrically disconnected from the system due to a power failure to the system by remote operation after power recovery of the system. The present invention relates to a system reconnection apparatus and a system reconnection system.

  In the conventional solar power generation system, when a reverse power flow from the solar power generation system is generated at the time of a power failure of the system, power flows to the system that should have been out of power, which may cause an accident. In order to prevent this, normally, at the time of a power failure of the system, the power conditioner is electrically disconnected from the system, and when the power recovery of the system can be confirmed, the power conditioner is reconnected to the system.

  Patent Document 1 discloses a solar power generation system capable of easily returning the solar power generation system when a system power failure occurs. In this solar power generation system, the control device has a display screen, and the display screen displays information on the operation method such as "Please touch the" Return button "below" when power is restored. And a return button that the user touches when returning the solar power generation system.

JP 2014-143890 A

  However, in the photovoltaic power generation system disclosed in Patent Document 1, since the user has to touch the return button, the control device is installed in a remote place, particularly like a so-called distributed power source. In some cases, it is difficult to realize system reconnection early after the system recovers.

  On the other hand, if the user tries to automatically reconnect the grid without touching the return button, a reverse power flow problem may occur in the distribution bank. However, there is a problem that it may violate the grid interconnection technical requirement guidelines established by the Agency for Natural Resources and Energy.

  Specifically, a photovoltaic power generation facility linked to a high-voltage interconnection or a high-voltage power-receiving private electric facility is operated when a power failure of the system causes an undervoltage relay, which is a system protection element, to operate. Even if the relay is restored, automatic reconnection is not possible, and the work of reconnecting the power conditioner etc. to the system is purposely done by the chief electric engineer, electric management engineer, etc. I had to go to the installation position.

  Therefore, an object of the present invention is to realize system reconnection after power recovery by remote control under the condition that the reverse power flow problem does not occur.

In order to solve the above problems, the system reconnection apparatus and the system reconnection system of the present invention are:
Means for detecting a power failure in the system (for example, power failure detection means 120 in FIG. 2);
When a power failure is detected by the means for detecting the power failure, a pair of external abnormal stop terminals (for example, the terminal 310a in FIG. 1) provided on a target (for example, the power conditioner 300 in FIG. 1) connected to the system. , 310b) (for example, the control unit 140 in FIG. 2),
Means for receiving a reconnection instruction transmitted after power recovery of the system (for example, the communication means 130 in FIGS. 2 and 3);
Means (for example, control means 140 in FIG. 2) for opening the external abnormal stop terminals in accordance with the reconnection instruction received by the receiving means.

  According to the present invention, the external abnormal stop terminal provided in the power conditioner or the like can be connected to the power conditioner or the like at a normal time even if the electric chief engineer, the electric management engineer or the like does not reconnect to the system manually. You can switch to the state.

  In particular, power conditioners and the like have different configurations depending on manufacturers, but since all power conditioners have an external abnormal stop terminal in common, the present invention is a type of power conditioner. Regardless of this, there is a remarkable effect that system reconnection can be performed.

In addition, this system reconnection apparatus is, for example,
A pair of output terminals (for example, the output terminals 110a and 110b in FIGS. 1 to 3 and 5) connected to the external abnormal stop terminal,
A terminal indirect point (for example, contact point 140b in FIGS. 3 and 5) connected between the output terminals and in a short circuit state from an open state at the time of a power failure of the system,
You may comprise by the means (for example, control means 140 of FIG. 2) which switches the said terminal indirect point from a short circuit state to an open state according to the said reconnection instruction | indication.

The means for switching to the open state is
A first contact (for example, a contact 140a in FIG. 3 and a contact 160b in FIG. 5) that becomes a short circuit state from an open state when a reconnection instruction is received by the receiving means;
A first coil (for example, the coil 120a in FIG. 3 and the coil 160a in FIG. 5) that switches the terminal indirect point from the short-circuit state to the open state when the first contact is changed from the open state to the short-circuit state. May be.

  Further, when detecting the power failure or power recovery of the system or the execution of the process for opening the external abnormal stop terminals, a means for transmitting the detection result (for example, the communication means 130 in FIG. Communication means 160) may be provided.

The means for transmitting comprises:
A third contact (for example, contact 150b in FIG. 3) that becomes a short circuit state from an open state at the time of a power failure of the system;
A second coil (eg, coil 150a in FIG. 3) located downstream of the third contact;
A fourth contact (for example, a contact 150c in FIG. 3) that switches between an open state and a short-circuit state when the second coil is energized,
The detection result may be transmitted to a registered transmission destination when the fourth contact is changed from an open state to a short circuit state.

BEST MODE FOR CARRYING OUT THE INVENTION

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram showing a schematic configuration of a photovoltaic power generation system 1000 which is a system reconnection system according to an embodiment of the present invention. A photovoltaic power generation system 1000 illustrated in FIG. 1 includes a reconnection apparatus 100, a ground fault overvoltage relay 200, a power conditioner (hereinafter referred to as “power conditioner”) 300, and connection lines 400a and 400b, which will be described below. It is divided roughly into.

  In the present embodiment, an example of the photovoltaic power generation system 1000 will be described as an example of the grid reconnection system. However, the present invention is not limited to photovoltaic power generation but is electrically connected to the system during power outages such as wind power generation and hydroelectric power generation. As long as the system is equipped with a target such as a power conditioner that is shut down by the power supply and reconnected to the system after power recovery, it can be applied regardless of the type of power generation. Similarly, the present invention can be applied to a system including a cogeneration system, an inverter of a fuel cell system, and the like.

  The reconnection system 100 realizes the system reconnection of the power conditioner 300 by remote operation without directly operating the power conditioner 300 by the electrical chief engineer or the electric power management engineer when the system is restored. The reconnection system 100 includes a pair of output terminals 110a and 110b that are connected to a pair of external abnormal stop terminals 310a and 310b provided in the power conditioner 300, respectively. As will be described later, the output terminals 110a and 110b are configured to be electrically switched from an open state to a short circuit state when a system power failure occurs.

  As is known, the ground fault overvoltage relay 200 is a combination of a zero-phase transformer and the like, and disconnects the power conditioner 300 and the like from the system when a ground fault is detected, and is usually provided in a high-voltage power receiving facility such as a cubicle. ing. The ground fault overvoltage relay 200 is connected to a pair of external abnormal stop terminals 310a and 310b provided in the power conditioner 300 in order to electrically disconnect the power conditioner 300 from the system when a ground fault is detected. And a pair of output terminals 210a and 210b connected to each other.

  As is known, the power conditioner 300 includes an inverter that converts electricity generated by a solar panel (not shown) from direct current to alternating current. The power conditioner 300 includes external abnormal stop terminals 310a and 310b connected to the output terminals 110a and 110b of the reconnection apparatus 100 and the output terminals 210a and 210b of the ground fault overvoltage relay 200 via a pair of connection lines. .

  1 shows only one power conditioner 300, a plurality of power conditioners may be prepared. In this case, if the power conditioner 300 is set as a master, and the power conditioner 300 as a slave to the power conditioner 300 is connected in series in a multidrop manner and connected between the external abnormal stop terminals, the power conditioner 300 is reconnected to the system after the system power is restored. If connected, all the other power conditioners that become slaves will be reconnected to the system.

  The connection lines 400a and 400b connect the output terminals 110a and 110b of the reconnection apparatus 100 and the external abnormal stop terminals 310a and 310b of the power conditioner 300. Typically, reconnection device 100 and ground fault overvoltage relay 200 are physically located close to each other, and reconnection device 100 and power conditioner 300 are physically located far away. If there is, the output terminals 110a and 110b of the reconnection system 100 and the output terminals 210a and 210b of the ground fault overvoltage relay 200 may be connected by connection lines 400a and 400b, respectively.

  In other words, at the output terminals 210a and 210b of the ground fault overvoltage relay 200, a connection line connected to the output terminals 110a and 110b of the reconnection apparatus 100 and a connection line connected to the external abnormal stop terminals 310a and 310b of the power conditioner 300 You may connect in the aspect which pinches | interposes both. Thereby, the output terminals 110a and 110b and the external abnormality stop terminals 310a and 310b can be connected via the output terminals 210a and 210b.

  FIG. 2 is a block diagram showing a conceptual internal configuration of reconnection apparatus 100 shown in FIG. In addition to the output terminals 110a and 110b described above, FIG. 2 shows a power failure detection means 120, a communication means 130, a control means 140, and a power recovery detection means 150, which will be described below.

  The power failure detection means 120 detects a power failure of the system. The detection of the power failure may be realized by, for example, a relay circuit, monitoring of the commercial AC power supply may be realized by an electronic circuit or the like, or may be realized by a method other than these.

  When the communication unit 130 detects the power recovery of the system, the communication unit 130 transmits information indicating that the power recovery has been detected to a transmission destination such as an e-mail address set in advance, or transmits it from the transmission destination. Or a reconnection instruction to be received. As this e-mail address, for example, an electric chief engineer or the like who will send a reconnection instruction may be mentioned.

  The control means 140 short-circuits between the external abnormal stop terminals 310a and 310b of the power conditioner 300 when the power failure is detected by the power failure detection means 120, the power recovery of the system is detected by the power recovery detection means 150, and When a reconnection instruction is received by the communication means 130, the external abnormal stop terminals 310a and 310b of the power conditioner 300 are opened according to the instruction.

  The power recovery detection means 150 detects power recovery of the system. The detection of power recovery may be realized by, for example, a relay circuit, or monitoring of commercial AC power may be realized by an electronic circuit or the like, or may be realized by a method other than these.

  FIG. 3 is a circuit diagram showing an example in which the power failure detection means 120, the control means 140, and the power recovery detection means 150 of the reconnection apparatus 100 shown in FIG. 2 are realized by a relay circuit. Each of these means can be realized by the configuration shown in FIG. 5, for example, and is not limited to the configuration shown in FIG.

  Further, in FIG. 3, the coils 120a and 150a and the contacts 120c and the like whose switching states are switched by these are indicated by broken lines. That is, for example, in the case of the coil 120a, the switching state of the contacts 120c, 140b, 150b is switched. Note that the open / closed state of each contact 120c and the like shown in FIG. 3 indicates that the system is in a power outage.

  FIG. 4 is a timing chart showing the open / closed state of each contact 120c shown in FIG. In the timing chart shown in FIG. 4, the closed state is shown when each contact 120c or the like is Hi, and the open state is shown when it is Low. Hereinafter, the configuration example and the operation of the reconnection apparatus 100 will be described with reference to FIGS. 3 and 4.

  First, the relationship between each part shown in FIG. 3 and each means shown in FIG. 2 will be described. The power failure detection means 120 is mainly realized by a relay circuit including a coil 120a and an a contact 120c.

  The control means 140 is mainly realized by a relay circuit constituted by the coil 120a, the b contact 140b, and the a contact 140a.

  The power recovery detection means 150 is mainly realized by a relay circuit including a coil 150a and an a contact 150c.

  The power source of the reconnection apparatus 100 can be secured from, for example, an outlet power source of a cubicle provided with the ground fault overvoltage relay 200, or can be secured from a so-called commercial power source. For this reason, for example, if power is supplied to the cubicle, power is also supplied to the reconnection apparatus 100.

  The coil 120a can switch the open / closed state of the a contact 120c. Until the “power failure” of the system shown in FIG. 4 occurs, the coil 120a is energized, and the a contact 120c is closed by the excitation of the coil 120a. Further, when the a contact 120c is in the closed state, the coil 120a is energized, so that the closed state of the a contact 120c is maintained by the excitation of the coil 120a.

  Furthermore, until the “power failure” of the system occurs, the b contact 140b is opened by the excitation of the coil 120a. Therefore, in this case, the output terminals 110a and 110b are in an open state. Furthermore, the b-contact 150b is also opened by the excitation of the coil 120a until the “power failure” of the system occurs. For this reason, the coil 150a located downstream is not energized. This state is maintained while the coil 120a is energized.

  The coil 150a switches the open / closed state of the a contact 150c. The coil 150a is not energized until the system “power failure” occurs, so the a contact 150c is opened by exciting the coil 120a. This state is maintained while the coil 120a is energized.

  In summary, until the “power failure” of the system occurs, the open / closed states of the a contacts and the b contacts described so far are maintained as they are.

  The a contact 140a is configured to be switched between open and closed states by a coil or the like (not shown) in the communication unit 130. Specifically, the a contact 140a is temporarily switched to the closed state when a reconnection instruction is transmitted from the electrical chief engineer or the like after the system power is restored and received by the communication means 130. It is.

  Thereafter, when a “power failure” of the system occurs for some reason, the current flowing in the coil 120a is stopped, that is, the coil 120a is not energized. For this reason, since the coil 120a is not excited, the a contact 120c is switched from the closed state to the open state.

  Further, when the coil 120a is not energized due to the “power failure” of the system, the b contact 150b is switched from the open state to the closed state because the coil 120a is not excited. However, the coil 150a located downstream of the b contact 150b is not energized because no current flows due to a power failure of the system. For this reason, the a contact 150c incidental to the coil 150a remains open.

  Further, when the coil 120a is not energized due to the “power failure” of the system, the b contact 140b is switched from the open state to the closed state. As a result, the output terminals 110a and 110b are short-circuited. Thereby, as outlined with reference to FIG. 1, the external abnormal stop terminals 310a and 310b of the power conditioner 300 are also short-circuited through the connection lines 400a and 400b connected to the output terminals 110a and 110b, respectively.

  Note that the communication unit 130 may monitor the presence / absence of power supply to the own unit, so that when the power supply is stopped, the communication unit 130 may transmit the fact to a preset e-mail address.

  After that, if there is a “recovery” of the system shown in FIG. 4, power is supplied to the cubicle. Therefore, when power is secured from the cubicle, power is also supplied to the reconnection apparatus 100. Will be. This energizes the communication means 130 that is directly connected to the power terminals P1, P2.

  In addition, the coil 120a is not energized only when the system is restored, so the b contact 150b remains closed. Therefore, the coil 150a located downstream of the b contact 150b is energized and excited. Thereby, a contact 150c switches to a closed state.

  On the other hand, the communication means 130 has means for monitoring the connection terminal of the a-contact 150c in its own means. When the a-contact 150c is switched to the closed state, the communication means 130 is sent to a destination such as a preset e-mail address. To the effect that power recovery has been detected is transmitted.

  In response to this, when a “remote reconnection” instruction shown in FIG. 4 is given by an electrical chief engineer or the like who has confirmed that the electric power company may reconnect, the communication means 130 , And the a contact 140a is temporarily switched from the open state to the closed state. As a result, the coil 120a located downstream of the a contact 140a is energized and excited.

  Thereby, the a contact 120c attached to the coil 120a is switched from the open state to the closed state, the b contact 140b is switched from the closed state to the open state, and the b contact 150b is also switched from the closed state to the open state. When the a-contact 120c is closed, the coil 120a is energized even if the a-contact 140a that has been temporarily switched to the closed state is subsequently switched to the open state, so that the excitation is maintained.

  Further, when the b contact 140b is switched from the closed state to the open state by the excitation of the coil 120a by "remote reconnection", the output terminals 110a and 110b are opened, and as a result, the external abnormal stop terminal 310a of the power conditioner 300 is opened. 310b is also opened. Therefore, the power conditioner 300 will be out of the external abnormal state and reconnected to the system.

  Further, when the b contact 150b is switched from the closed state to the open state due to the excitation of the coil 120a by "remote reconnection", the coil 150a located downstream thereof is not energized, so the a contact 150c attached to the coil 150a is From the closed state to the open state. For this reason, the communication unit 130 monitors the terminal to which the contact a 150c is connected, thereby completing the execution of the process for opening the external abnormal stop terminals, that is, typically the system reconnection process. Can be sent to a preset email address.

  In order to manufacture the system reconnection system at a low cost, the coil 150a and the b contact 150b may be eliminated, and the open state and the short circuit state of the a contact 150c may be switched by exciting the coil 120a. Furthermore, a contact b may be used instead of the contact a 150c. Even in such a configuration, the communication unit 130 can monitor the terminal to which the a-contact 150c or the alternative b-contact is connected, thereby transmitting the completion to the preset e-mail address. it can.

  In the present embodiment, the example in which the control unit 140 and the like are realized using the relay circuit shown in FIG. 3 has been described. However, for example, it can be realized using a photocoupler. Specifically, for example, when a photocoupler is connected to the output terminals 110a and 110b and a power failure of the system is detected by the power failure detection means 120, the photocoupler is turned on. Further, when power recovery of the system is detected by the power recovery detection means 150 and a reconnection instruction is received by the communication means 130 thereafter, the photocoupler is set in an insulated state.

  In this way, system reconnection of the power conditioner 300 can be realized as in the case described with reference to FIG. The control of the photocoupler may be realized by preparing a program for causing the CPU to execute the above operation, storing the program in a memory, and cooperating with the CPU and the memory.

  FIG. 5 is a diagram showing a modification of the circuit diagram shown in FIG. 5 includes a detection / communication unit 160 in which the power failure detection unit 120, the power recovery detection unit 150, and the communication unit 130 illustrated in FIG. 2 are integrated, and an a contact 160b in which the a contacts 120c and 140a illustrated in FIG. 4 shows a coil 160a that performs a part of the operation of the coil 120a shown in FIG. Note that the a contact 160b and the b contact 140b shown in FIG.

  First, the a-contact 160b is in a closed state until a power failure occurs in the system, and thus the coil 160a is energized, so that the a-contact 160b is maintained closed by excitation of the coil 160a. Further, the b contact 140b is kept open by the excitation of the coil 160a.

  After that, it is assumed that a power outage occurs for some reason. For example, if the commercial AC power supply is monitored, the detection / communication unit 160 can detect a power failure in the system. Therefore, when the power failure is actually detected, the a contact 160b is switched from the closed state to the open state. As a result, the coil 160a is not energized, and the b contact 140b is switched from the open state to the closed state by the excitation of the coil 160a.

  After that, when the system recovers and the detection / communication means 160 detects the power recovery by, for example, monitoring the commercial AC power supply, the fact that the power recovery has been detected is detected in a preset e-mail address or the like. Send.

  In response to this, an electrical chief engineer who has confirmed that the power company can re-connect is instructed to perform remote re-connection, and when this instruction is received by the detection / communication means 160, the a contact 160b Is switched from the open state to the closed state. As a result, the coil 160a located downstream of the a contact 160a is energized and excited.

  Thereby, b contact 150b incidental to coil 160a switches from a closed state to an open state. For this reason, the output terminals 110a and 110b are opened, and the external abnormal stop terminals 310a and 310b of the power conditioner 300 are also opened. Therefore, the power conditioner 300 will be out of the external abnormal state and reconnected to the system.

It is a block diagram which shows the typical structure of the solar power generation system 1000 which is the system | strain reconnection system of embodiment of this invention. It is a block diagram which shows the notional internal structure of the reconnection apparatus 100 shown in FIG. It is a circuit diagram which shows the example which implement | achieved the power failure detection means 120, the control means 140, and the power recovery detection means 150 of the reconnection apparatus 100 shown in FIG. 2 by the relay circuit. FIG. 4 is a timing chart showing an open / close state of each contact 120c and the like shown in FIG. It is a figure which shows the modification of the circuit diagram shown in FIG.

100 reconnection device 200 ground fault overvoltage relay 110a, 110b, 210a, 210b output terminal 120 power failure detection means 120a coil 120ca contact a 130 communication means 140 control means 140a contact a 140b contact b power recovery detection means 150a coil 150b contact b 150c a contact point 160 detection / communication means 160a coil 160b a contact point 300 power conditioner 310a, 310b external abnormal stop terminal 400a, 400b connection line 1000 photovoltaic power generation system P1, P2 power supply terminal

Claims (6)

A means of detecting power outages in the system;
Means for short-circuiting between a pair of external abnormal stop terminals provided in a power source connected to the system when a power failure is detected by the means for detecting the power failure;
Means for receiving a reconnection instruction transmitted after power recovery of the system;
Means for opening between the external abnormal stop terminals according to a reconnection instruction received by the means for receiving;
System reconnection device comprising: A pair of output terminals each connected to the external abnormal stop terminal;
A terminal indirect point that is connected between the output terminals and is short-circuited from an open state during a power failure of the system,
Means for switching the terminal indirect point from a short-circuited state to an open state in accordance with the reconnection instruction;
The system reconnection apparatus according to claim 1, comprising: The means for switching to the open state is
A first contact that goes from an open state to a short circuit state when a reconnection instruction is received by the means for receiving;
A first coil that switches the terminal indirect point from the short-circuited state to the open-state when the first contact is switched from the open state to the short-circuited state;
The system reconnection apparatus of Claim 2 provided with these.   The system reconnection apparatus according to claim 1, further comprising means for transmitting the detection result when detecting a power failure or power recovery of the system, or execution of a process of opening between the external abnormal stop terminals. The means for transmitting comprises:
A third contact that goes from an open state to a short-circuit state during a power failure in the system;
A second coil located downstream of the third contact;
A fourth contact that switches from an open state to a short circuit state when the second coil is energized,
The system reconnection apparatus according to claim 4, wherein the detection result is transmitted to a registered transmission destination when the fourth contact is changed from an open state to a short circuit state. The system reconnection apparatus according to any one of claims 1 to 5,
A target to be reconnected to the system by the system reconnection device;
A grid reconnection system.

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