JP2016019390A - Photovoltaic power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photovoltaic power generation system capable of suppressing both series arc and parallel arc.SOLUTION: A photovoltaic power generation system 1 comprises: a solar cell string 2 including a plurality of solar cell modules 11, and inner-string connection parts 12 for making the solar cell modules 11 connect in series with each other; a load 3 to which power generated by the solar cell string 2 is supplied; a first connection part 4 for making one terminal of the load 3 and one terminal of the solar cell string 2 connect with each other; a second connection part 5 for making the other terminal of the load 3 and the other terminal of the solar cell string 2 connect with each other; an arc detection part 14 for detecting generation of an arc in the photovoltaic power generation system 1; and a disconnection part 15 for electrically disconnecting an inner-string connection part 12 in the solar cell string 2 when the arc detection part 14 has detected generation of an arc.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a photovoltaic power generation system.

  In solar power generation systems, arcs (arc faults) may occur due to damage to connections such as wiring and terminals. Such arcs may be caused by poor conduction or poor contact in the solar power generation system. There are a series arc generated and a parallel arc generated due to an insulation failure in the system. For example, in the series arc detection control device described in Patent Document 1, it is determined whether or not a series arc is generated by analyzing the measured current and voltage. The input terminal is open.

Special table 2013-5004766 gazette

  Here, in the prior art, as described above, since the input terminal of the power converter circuit is opened, the series arc can be suppressed when a series arc occurs, but when the parallel arc occurs. Is not preferable because the parallel arc may be strengthened. Moreover, it is conceivable to suppress a parallel arc by short-circuiting a part of the photovoltaic power generation system. In this case, however, the series arc may be strengthened when the series arc is generated.

  Then, an object of this invention is to provide the solar power generation system which can suppress both a serial arc and a parallel arc.

  A photovoltaic power generation system according to one aspect of the present invention includes a plurality of solar cell modules, an in-string connection unit that connects the solar cell modules in series, a load to which power generated by the solar cell string is supplied, and a load A first connection portion that connects one terminal of the solar cell and one terminal of the solar cell string to each other, a second connection portion that connects the other terminal of the load and the other terminal of the solar cell string, and a solar power generation system And an arc detector that detects the occurrence of arc in the solar cell, and a cutting portion that electrically disconnects the connection portion in the string in the solar cell string when the arc detector detects the occurrence of the arc.

  In this solar power generation system, when the generation of an arc is detected by the arc detection unit, the connection unit in the string in the solar cell string is electrically disconnected by the cutting unit. Thereby, when a series arc occurs, the series arc can be suppressed. In addition, the current in the circuit where the parallel arc is generated is cut off by electrically disconnecting the connection part in the string. Thereby, when a parallel arc occurs, the parallel arc can be suppressed. That is, both the series arc and the parallel arc in the photovoltaic power generation system can be suppressed by electrically disconnecting the in-string connecting portion when the occurrence of the arc is detected.

  In the photovoltaic power generation system according to one aspect of the present invention, the length of the in-string connection portion may be shorter than the lengths of the first connection portion and the second connection portion. In this case, in the photovoltaic power generation system, an arc is more likely to occur in the first and second connection portions than in the connection portion in the string, and the first and second connections are made by electrically disconnecting the connection portion in the string. It is possible to suitably suppress the arc generated in the part.

  In the solar power generation system according to one aspect of the present invention, the cutting unit may at least electrically disconnect the in-string connection unit corresponding to the midpoint of the solar cell string or the vicinity of the midpoint. In this case, not only can the parallel arc generated between the first connection portion and the second connection portion be reliably extinguished, but also the residual voltage in each of the electrically disconnected solar cell strings can be effectively reduced (at least the solar cell). The residual voltage of each battery string is almost halved). Therefore, for example, even when an insulation failure occurs at an unexpected location, parallel arcs can be hardly generated.

  In the photovoltaic power generation system according to one aspect of the present invention, the arc detection unit and the cutting unit may be arranged in the same in-string connection unit. In this case, compared with the case where an arc detection part and a cutting | disconnection part are provided in the separate place in a solar power generation system, a solar power generation system becomes a simple structure.

  In the photovoltaic power generation system according to one aspect of the present invention, the solar cell string includes a plurality of substrings and an intersubstring connecting portion that connects the substrings in series, and each of the plurality of substrings includes a plurality of substrings. The solar cell module and the solar cell modules are connected in series and include a connection part in the substring shorter than the connection part between the substrings, and the cutting part detects the occurrence of an arc in the photovoltaic power generation system. At this time, the in-substring connecting portion in any of the plurality of substrings may be electrically disconnected. In this case, in the solar cell string, an arc is more likely to occur in the connection part between substrings than in the connection part in substring. However, it is generated in the connection part between substrings by electrically disconnecting the connection part in substring. It is possible to suitably suppress the arc to be performed.

  The photovoltaic power generation system according to one aspect of the present invention may include a solar cell array in which a plurality of solar cell strings are connected in parallel to each other.

  In the photovoltaic power generation system according to another aspect of the present invention, a first solar cell array in which a plurality of first solar cell strings are connected in parallel to each other and a second solar cell string in which a plurality of second solar cell strings are connected in parallel to each other. A solar cell array, an inter-array connection that connects the first solar cell array and the second solar cell array in series with each other, a load to which power generated by the first solar cell array and the second solar cell array is supplied, A first connection part for connecting one terminal of the load and the first solar cell array to each other, and a second connection part for connecting the other terminal of the load and the second solar cell array to each other, and a plurality of first solar cells Each of the battery string and the plurality of second solar cell strings has a plurality of solar cell modules and an in-string connecting portion that connects the solar cell modules in series, and An arc detector that detects the occurrence of an arc in the system, and a cutting portion that electrically disconnects at least one of the connection portion in the string and the connection portion between the arrays when the arc detection portion detects the occurrence of the arc. Prepare.

  In this solar power generation system, when the generation of an arc is detected by the arc detection unit, at least one of the in-string connection unit and the inter-array connection unit is electrically disconnected by the cutting unit. Thereby, when a series arc occurs, the series arc can be suppressed. In addition, by electrically disconnecting the connection part in the string or the connection part between the arrays, it is possible to reduce the residual voltage that contributes to the generation of the parallel arc in the solar cell array, and to make it difficult to generate the parallel arc. Therefore, when a parallel arc occurs, the parallel arc can be suppressed. That is, it is possible to suppress both the series arc and the parallel arc in the photovoltaic power generation system by electrically disconnecting at least one of the in-string connection portion and the inter-array connection portion when the occurrence of the arc is detected. .

  In a photovoltaic power generation system according to another aspect of the present invention, a solar cell string having a plurality of solar cell modules and an in-string connecting portion that connects the solar cell modules in series, and electric power generated by the solar cell string A load to be supplied, a first connection portion for connecting one terminal of the load and one terminal of the solar cell string to each other, and a second connection portion for connecting the other terminal of the load and the other terminal of the solar cell string to each other And an arc detector that detects the occurrence of an arc in the photovoltaic power generation system, and when the arc detector detects the occurrence of an arc, at least one of the first connection portion and the second connection portion is electrically connected from the solar cell string. And a cutting section for cutting.

  In this solar power generation system, when the generation of an arc is detected by the arc detection unit, at least one of the first connection unit and the second connection unit is electrically disconnected from the solar cell string by the cutting unit. Here, the first connection portion and the second connection portion are used to connect the load and the solar cell string to each other, and are highly likely to be directly affected by the external environment such as the weather, so that an arc is likely to occur. It is a connection part. For example, when an arc is generated in the first connection portion, the solar cell string that is the power generation unit can be electrically disconnected from the arc generation location by electrically disconnecting the first connection portion from the solar cell string. . Therefore, when it is detected that an arc has occurred in the solar power generation system, at least one of the first connection portion and the second connection portion is electrically disconnected from the solar cell string, thereby connecting the series in the solar power generation system. Both arcs and parallel arcs can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the solar power generation system which can suppress both a serial arc and a parallel arc can be provided.

It is a schematic block diagram which shows the solar energy power generation system which concerns on 1st Embodiment. It is the figure which expanded the broken-line part of FIG. It is a flowchart explaining the arc elimination method by the solar energy power generation system which concerns on 1st Embodiment. It is a figure for demonstrating an example of the arc elimination method by the solar energy power generation system which concerns on a comparative example. It is a figure for demonstrating another example of the arc elimination method by the solar energy power generation system which concerns on a comparative example. (A) is a schematic block diagram which shows the solar power generation system which concerns on the 1st modification of 1st Embodiment, (b) shows the solar power generation system which concerns on the 2nd modification of 1st Embodiment. It is a schematic block diagram, (c) is a schematic block diagram which shows the solar energy power generation system which concerns on the 3rd modification of 1st Embodiment. It is a schematic block diagram which shows the solar energy power generation system which concerns on the 4th modification of 1st Embodiment. It is a schematic block diagram which shows the solar energy power generation system which concerns on the 5th modification of 1st Embodiment. It is a schematic block diagram which shows the solar energy power generation system which concerns on the 6th modification of 1st Embodiment. It is a schematic block diagram which shows the solar energy power generation system which concerns on the 7th modification of 1st Embodiment. It is a schematic block diagram which shows the solar energy power generation system which concerns on the 8th modification of 1st Embodiment. It is a schematic block diagram which shows the solar energy power generation system which concerns on the 9th modification of 1st Embodiment. It is a schematic block diagram which shows the solar energy power generation system which concerns on the 10th modification of 1st Embodiment. It is a schematic block diagram which shows the solar energy power generation system which concerns on 2nd Embodiment. It is a schematic block diagram which shows the solar energy power generation system which concerns on the modification of 2nd Embodiment. It is a schematic block diagram which shows the solar energy power generation system which concerns on 3rd Embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same or equivalent elements will be denoted by the same reference numerals, and redundant description will be omitted.

(First embodiment)
FIG. 1 is a schematic configuration diagram illustrating a photovoltaic power generation system according to the first embodiment. As shown in FIG. 1, the solar power generation system 1 is a power generation system that generates power using solar energy. The photovoltaic power generation system 1 includes a solar cell string 2, a load 3, a first connection portion 4 that connects one terminal of the load 3 and one terminal of the solar cell string 2, the other terminal of the load 3, and And a second connection portion 5 that connects the other terminals of the solar cell string 2 to each other.

  The solar cell string 2 functions as a DC circuit that converts sunlight energy into electric energy and supplies the electric energy to the load 3 as a DC output. The solar cell string 2 includes a plurality of solar cell modules 11, a plurality of in-string connection portions 12 that connect the solar cell modules 11 in series, and an arc detection cutting portion 13. The in-string connection portion 12 is a wiring such as a cable, and may include a backflow prevention diode or a fuse element. The solar cell string 2 does not include the first connection part 4 and the second connection part 5. The solar cell module 11 is configured in a panel shape, for example, and includes a plurality of solar cells (not shown) connected in series with each other. The solar cell string 2 is installed, for example, on a gantry or a roof.

  The load 3 is a device to which power generated by the solar cell string 2 is supplied. The load 3 has, for example, a power conditioner, an inverter, a converter, or a storage battery. When the load 3 has a power conditioner, the load 3 converts the direct current output supplied from the solar cell string 2 into an alternating current output, and the alternating current output is an electronic device such as a storage battery system, home appliances, or an electric power system. (For example, commercial power system).

  The 1st connection part 4 and the 2nd connection part 5 are wirings, such as a cable used in order to connect the solar cell string 2 to the load 3, and may include a backflow prevention diode, a fuse element, an extension cable, or a disconnector etc. Good. In a general photovoltaic power generation system, a plurality of solar cell modules are installed adjacent to each other on an outdoor flat land or roof to which sunlight is irradiated, and the load is from the above solar cell modules such as indoors or under an eaves. Often installed in remote locations. Therefore, the 1st connection part 4 and the 2nd connection part 5 are longer than the connection part 12 in a string which connects the solar cell modules 11 mutually. That is, the length of the in-string connection portion 12 is shorter than the lengths of the first connection portion 4 and the second connection portion 5.

  The first connecting part 4 and the second connecting part 5 include, for example, a cable straddling a pedestal or a roof surface, or ground wiring, etc., such as the influence of weather such as sunlight, rain, or wind, contact of humans or animals, etc. Highly likely to be directly affected by the impact or other external environment. For this reason, the possibility that deterioration or peeling of the insulator covering the cables of the first connection part 4 and the second connection part 5 or disconnection or the like in a part of the cable is higher than that of the in-string connection part 12. Therefore, arcs (series arc and parallel arc) are more likely to occur in the first connection portion 4 and the second connection portion 5 than in the in-string connection portion 12. That is, in this embodiment, the 1st connection part 4 and the 2nd connection part 5 are arc generation object connection parts (henceforth only an arc generation object connection part) in which an arc is easy to generate | occur | produce in the solar power generation system 1. FIG. is there.

  FIG. 2 is an enlarged view of the vicinity of the broken line in FIG. As shown in FIG. 2, the arc detection cutting unit 13 is installed in the in-string connection unit 12 in the solar cell string 2, and is in the solar power generation system 1 (that is, the direct current constituting the solar power generation system 1). When the occurrence of an arc is detected in the circuit), the in-string connecting portion 12 is electrically disconnected. For example, the in-string connecting portion 12 is electrically disconnected by controlling a switch in the arc detection cutting portion 13. As shown in FIG. 1, the arc detection cutting unit 13 electrically cuts the in-string connection unit 12 corresponding to the midpoint of the solar cell string 2. The arc detection cutting unit 13 is also referred to as an arc fault circuit interrupter (AFCI). Here, the midpoint of the solar cell string 2 is an intermediate potential portion between both ends of the solar cell string 2. For example, when an odd number of solar cell modules 10 are connected in series in the solar cell string 2 or when intermediate potential portions at both ends of the solar cell string 2 are in the solar cell module 10, The corresponding in-string connecting portion 12 may be electrically disconnected. The in-string connection portion 12 corresponding to the vicinity of the midpoint is the in-string connection portion 12 closest to the midpoint of the solar cell string 2.

  An example of a method in which the arc detection cutting unit 13 detects an arc will be described. For example, “Differentiating series and parallel photovoltaic arc-faults”, J. Johnson, M. Montoya, S. McCalmont, G., F. Fuks, J. Earle, A. Fresquez, S. Gonzalez, J This is described in Granata, Photovoltaic Specialists Conference (PVSC), 38th IEEE (2012). The arc detection cutting unit 13 detects an arc by measuring a direct current waveform flowing through the solar power generation system 1. For example, arc generation is detected by comparing a direct current waveform flowing through the photovoltaic power generation system 1 (especially the arc detection cutting unit 13) with a reference current waveform stored in the arc detection cutting unit 13 every predetermined time. Is called. Here, when the fluctuation component of the predetermined frequency in the direct current waveform after the lapse of a predetermined time is larger than a predetermined threshold, it is detected that an arc has occurred in the photovoltaic power generation system 1. The arc detection cutting unit 13 is, for example, a measuring device that measures a current waveform, a storage unit that stores a reference current waveform, and a comparison detection unit (arc detection) that compares the DC current waveform and the reference current waveform to detect arc generation. Part) and a cutting part for electrically cutting the in-string connecting part 12, which are integrally formed and arranged in the same in-string connecting part 12. As the cutting part, a semiconductor switch such as an FET (Field Effect Transistor) or a mechanical switch such as a relay switch can be used. A cutting part is connected in series in the middle of the connection part 12 in a string, and the electric circuit of the solar cell string 2 is interrupted | blocked by the said cutting part being open | released (or becoming OFF).

  FIG. 3 is a flowchart for explaining an arc elimination method by the photovoltaic power generation system according to the first embodiment. First, as shown in FIG. 3, the arc detection cutting unit 13 observes the current flowing through the photovoltaic power generation system 1 (S1). For example, the arc detection cutting unit 13 measures a transition (DC current waveform) of a direct current value flowing through the arc detection cutting unit 13 within a predetermined period. When the arc detection cutting unit 13 detects that an arc is generated in the photovoltaic power generation system 1 (S2: YES), the arc detection cutting unit 13 electrically cuts the in-string connection unit 12 of the solar cell string 2. (S3). When the arc detection / cutting unit 13 does not detect that an arc is generated in the solar power generation system 1 (S2: NO), the arc detection / cutting unit 13 continues to observe the current flowing through the solar power generation system 1.

  Next, the effect of the photovoltaic power generation system 1 according to the first embodiment will be described. First, a method for eliminating an arc generated in the photovoltaic power generation system 100 according to the comparative example will be described with reference to FIGS. 4 and 5. FIG.4 and FIG.5 is a figure for demonstrating an example of the arc elimination method by the solar power generation system 100 which concerns on a comparative example. As shown in FIGS. 4 and 5, the solar power generation system 100 has the same configuration as the solar power generation system 1 except that the solar cell string 102 does not have an arc detection cutting part. . As a general method for eliminating the arc of such a photovoltaic power generation system 100, for example, a method of opening the solar cell string 102 from the load 3 (specifically, the first connection unit 4 and / or the second connection unit 5). And the method of short-circuiting the solar cell string 102 (specifically, the end of the first connection 4 on the load 3 side and the load 3 side of the second connection 5) For example, a method of connecting the end of each of them. The arc elimination method described above is generally performed by switching the connection state of the switch in a load 3 such as a power conditioner or in a connection box in which the load 3 or the like can be accommodated. Therefore, when the arc elimination method described above is employed, the first connection portion 4 and the second connection portion 5 are connected to the solar cell string 102.

  FIG. 4A shows a diagram when a series arc is generated in the photovoltaic power generation system 100, and FIG. 4B shows a diagram in which a load is released from the solar cell string when the series arc is generated. FIG. 4C shows a diagram in which the solar cell string is electrically disconnected from the load and then short-circuited when a series arc is generated. As shown in FIG. 4A, for example, when a part of the first connection portion 4 of the photovoltaic power generation system 100 becomes defective in conduction or contact, a series arc is generated in the first connection portion 4. When a series arc is detected, in the comparative example, the load 3 is released from the solar cell string 102 as shown in FIG. 4 (b), or the load 3 is short-circuited as shown in FIG. 4 (c). Thus, the series arc can be suppressed or eliminated.

  As shown in FIG. 4B, when the load 3 is released from the solar cell string 102, the photovoltaic power generation system 100, which is a DC circuit, becomes an open circuit, and the series arc is eliminated. On the other hand, as shown in FIG. 4C, when the solar cell string 102 is short-circuited, a closed circuit including the solar cell string 102 that is the power generation unit and the series arc location is maintained, so that the series arc is eliminated or Not suppressed. Further, when the solar cell string 102 is short-circuited, the current flowing through the solar cell string 102 is increased by the absence of the resistance of the load 3 in the closed circuit, and the series arc may be strengthened (expanded).

  FIG. 5A shows a diagram when a parallel arc occurs in the photovoltaic power generation system, and FIG. 5B shows a state in which the solar cell string is electrically disconnected from the load when the parallel arc occurs. FIG. 5C shows a diagram in which the load is released from the solar cell string when a parallel arc occurs. As shown in FIG. 5A, for example, when a part of the first connection part 4 and the second connection part 5 of the photovoltaic power generation system 100 becomes poorly insulated, the first connection part 4 and the second connection part 5 A parallel arc occurs between the two. When a parallel arc is detected, in the comparative example, the load 3 is short-circuited as shown in FIG. 5 (b), or the load 3 is released from the solar cell string 102 as shown in FIG. 5 (c). Thus, the parallel arc can be suppressed or eliminated.

  As shown in FIG. 5B, when the solar cell string 102 is short-circuited, the position where the solar cell string 102 is short-circuited rather than the parallel arc generation position in the first connection unit 4 and the second connection unit 5 is used. As a result, a large amount of current flows, eliminating the parallel arc. On the other hand, as shown in FIG. 5C, when the load 3 is released from the solar cell string 102, the parallel arc in the photovoltaic power generation system 1 is not eliminated or suppressed. Further, when the load 3 is released from the solar cell string 102, the current due to the residual voltage of the solar cell string 102 flows in a concentrated manner at the location where the parallel arc is generated, and thus the parallel arc may be strengthened. is there.

  From the above, in the method for eliminating the arc generated in the photovoltaic power generation system 100 according to the comparative example, the arc may expand unless appropriate measures are taken according to the type of the generated arc. Here, it is difficult to accurately determine whether the arc generated in the photovoltaic power generation system 100 is a series arc or a parallel arc. For this reason, in the above-mentioned method, there is a possibility that the generation of the arc cannot be eliminated or suppressed and the arc may be enlarged. Further, for example, by providing a switch for each solar cell module and individually controlling the switch, it is possible to theoretically deal with either a series arc or a parallel arc. However, in this case, the configuration of a circuit for individually controlling the switches becomes complicated.

  In contrast, in the photovoltaic power generation system 1 according to the first embodiment, when the arc detection cutting unit 13 detects the occurrence of an arc in the photovoltaic power generation system 1, a plurality of strings in the solar cell string 2 are detected. At least one of the inner connection parts 12 is electrically disconnected by the arc detection cutting part 13. Thereby, when a series arc occurs, the series arc can be suppressed or eliminated.

  In addition, even when a parallel arc occurs, by electrically disconnecting the in-string connecting portion 12, the circuit including the parallel arc portion is electrically disconnected from the solar cell string 2 that is a power generation source, The current in the circuit causing the parallel arc can be interrupted. Thereby, since it becomes possible to extinguish a parallel arc, when a parallel arc generate | occur | produces, the said parallel arc can be suppressed or eliminated. Therefore, both the series arc and the parallel arc in the solar power generation system 1 can be suppressed or eliminated by a simple configuration in which the in-string connection portion 12 is electrically disconnected when the occurrence of the arc is detected.

  Moreover, in the solar power generation system 1 which concerns on 1st Embodiment, the length of the connection part 12 in a string is shorter than the length of the 1st and 2nd connection parts 4 and 5. FIG. In this case, the first and second connection portions 4 and 5 are connection portions that are more likely to generate an arc than the in-string connection portion 12. By electrically disconnecting the in-string connection portion 12, the first and second connection portions 4 and 5 It becomes possible to suppress suitably the arc which generate | occur | produces in 2 connection parts 4 and 5. FIG. That is, it can be said that this solar power generation system 1 has a configuration corresponding to the case where the first and second connection portions 4 and 5 are arc generation target connection portions.

  In the photovoltaic power generation system 1 according to the first embodiment, the arc detection cutting unit 13 electrically cuts the in-string connection unit 12 corresponding to the midpoint of the solar cell string 2. In this case, not only can the parallel arc generated between the first connection portion 4 and the second connection portion 5 be extinguished reliably, but the residual voltage in each of the electrically disconnected solar cell strings 2 is halved, The residual voltage in each of the solar cell strings 2 can be effectively reduced. For example, an arbitrary in-string connection portion 12 in the photovoltaic power generation system 1 has caused an unexpected parallel arc with the first connection portion 4, the second connection portion 5, or another in-string connection portion 12. Even in this case, it is possible to reduce the voltage supplied to the parallel arc location to half or less of the electromotive voltage of the solar cell string 2. Therefore, even when an insulation failure or the like occurs at an unexpected location in the solar power generation system 1, it is difficult to generate a parallel arc.

  Moreover, in the solar power generation system 1 which concerns on 1st Embodiment, the arc detection part which detects generation | occurrence | production of the arc in the said solar power generation system 1, and the connection in a string when the said arc detection part detects generation | occurrence | production of an arc An arc detection cutting part 13 integrated with a cutting part for electrically cutting the part 12 is installed in the same in-string connecting part 12. In this case, compared with the case where an arc detection part and a cutting | disconnection part are provided in the separate place in a solar power generation system, the solar power generation system 1 becomes a simple structure.

  Next, first to tenth modified examples of the first embodiment will be described. In the description of the first to tenth modified examples, differences from the first embodiment will be mainly described.

  Fig.6 (a) is a schematic block diagram which shows the solar energy power generation system which concerns on a 1st modification. As shown in FIG. 6A, the photovoltaic power generation system 1A has an arc detection unit 14 and a cutting unit 15 separately. The arc detector 14 detects the occurrence of an arc in the solar power generation system 1. Although the arc detection unit 14 is installed in the first connection unit 4, it may be installed in the solar cell string 2 </ b> A or may be installed in the second connection unit 5. The arc detector 14 detects an arc by observing the waveform of a direct current flowing through the photovoltaic power generation system 1A (particularly between the terminals of the load 3). The arc detection by the arc detection unit 14 is the same as the arc detection by the arc detection cutting unit 13. Therefore, the arc detection unit 14 includes, for example, a measuring device that measures a current waveform, a storage unit that stores a reference current waveform, and a comparison detection unit that compares the DC current waveform and the reference current waveform to detect arc occurrence. Contains. The terminal of the load 3 has a terminal to which the first connection part 4 is connected and a terminal to which the second connection part 5 is connected.

  The cutting part 15 is installed in the connection part 12 in a string, and when the generation | occurrence | production of an arc is detected by the arc detection part 14, the connection part 12 in a string of the solar cell string 2A is electrically cut | disconnected. The cutting part 15 is included in the solar cell string 2A. The cutting unit 15 is controlled by the arc detection unit 14. It is preferable that the cutting part 15 cut | disconnects the connection part 12 in a string corresponding to the midpoint of the solar cell string 2A. The cutting unit 15 is a switch that electrically disconnects the in-string connection unit 12, for example. The cutting unit 15 is connected to the arc detection unit 14 via a wiring (for example, a signal line).

  Also in the first modified example described above, both the series arc and the parallel arc in the photovoltaic power generation system 1A are suppressed or reduced by a simple configuration in which the connection part 12 in the string is electrically disconnected when the occurrence of arc is detected. There exists an effect that it can be eliminated.

  FIG.6 (b) is a schematic block diagram which shows the solar energy power generation system which concerns on a 2nd modification. As illustrated in FIG. 6B, the solar power generation system 1 </ b> B includes an arc detection unit 16 and a cutting unit 15. The arc detector 16 detects the occurrence of an arc in the solar power generation system 1B. The arc detector 16 detects an arc by observing a DC voltage waveform between the terminals of the load 3.

  An example of a method in which the arc detection unit 16 detects an arc will be described. The arc detector 16 detects the occurrence of an arc by comparing the DC voltage waveform between the terminals of the load 3 with a reference value stored in the arc detector 16 every predetermined time. Here, when the component of the specific frequency in the DC voltage waveform after the lapse of a predetermined time exceeds the reference value, it is detected that an arc has occurred in the photovoltaic power generation system 1. Therefore, the arc detection unit 16 includes, for example, a measuring device that measures a voltage waveform, a storage unit that stores a reference value, and a comparison detection unit that detects the occurrence of an arc based on a specific frequency component in the DC voltage waveform. Yes.

  Also in the second modification described above, both the series arc and the parallel arc in the photovoltaic power generation system 1B are suppressed or reduced by a simple configuration in which the in-string connection portion 12 is electrically disconnected when the occurrence of the arc is detected. There exists an effect that it can be eliminated.

  FIG.6 (c) is a schematic block diagram which shows the solar energy power generation system which concerns on a 3rd modification. As illustrated in FIG. 6C, the solar power generation system 1 </ b> C includes an arc detection unit 17 and a cutting unit 15. The arc detection unit 17 includes an arc detection unit 14 and an arc detection unit 16. The cutting part 15 electrically cuts the in-string connection part 12 of the solar cell string 2A when any of the arc detection parts 14 and 16 detects the occurrence of an arc. Also in the third modified example described above, both the series arc and the parallel arc in the solar power generation system 1C are suppressed or reduced by a simple configuration in which the in-string connection portion 12 is electrically disconnected when the occurrence of arc is detected. There exists an effect that it can be eliminated. Further, when any one of the arc detectors 14 and 16 detects the occurrence of an arc, the cutting unit 15 electrically disconnects the in-string connecting portion 12 of the solar cell string 2A, so that effective solar power generation is achieved. It becomes possible to suppress the arc in the system 1C.

  FIG. 7 is a schematic configuration diagram illustrating a photovoltaic power generation system according to a fourth modification. As shown in FIG. 7, the solar cell string 2B in the photovoltaic power generation system 1D includes a plurality of substrings 21 and a plurality of substring connecting portions 22 that connect the substrings 21 in series. . Each of the plurality of substrings 21 includes a plurality of solar cell modules 11, a plurality of substring connecting portions 23 that connect the solar cell modules 11 in series, and an arc detection cutting unit 13. Each of the plurality of substrings 21 is a series module group partitioned by the first connection portion 4, the second connection portion 5, or the intersubstring connection portion 22. However, when one end of the substring 21 is connected to the first connection portion 4 and the other end is connected to the second connection portion 5, the substring 21 is not a substring but a solar cell string.

  The inter-substring connecting portion 22 is, for example, an extension cable, an embedded cable, a cable straddling a pedestal or a roof surface, a ground wiring, an overhead line, or the like, and may include a backflow prevention diode or a fuse element. When the solar cell strings 2B are arranged on the roof surface or the like, the solar cell modules 11 may be connected to each other across a ridge, a descending ridge, or the like depending on the shape, structure, or area of the roof. The inter-substring connecting portion 22 is a wiring used when the solar cell modules 11 are separated from each other as described above, and is highly likely to be directly affected by the external environment. For this reason, the possibility that deterioration or peeling of the insulator covering the cable of the inter-substring connecting portion 22 or disconnection or the like in a part of the cable is higher than that of the intra-substring connecting portion 23. Therefore, an arc is more likely to occur in the inter-substring connecting portion 22 than in the sub-string connecting portion 23. That is, the connection part 22 between substrings is an arc generation object connection part in the solar cell string 2B. Further, the length of the intra-substring connecting portion 23 is shorter than the length of the inter-substring connecting portion 22. The inter-substring connecting portion 22 and the intra-substring connecting portion 23 correspond to the intra-string connecting portion 12.

  When the arc detection cutting unit 13 detects that an arc has occurred in the photovoltaic power generation system 1D, the arc detection cutting unit 13 in the plurality of substrings 21 electrically disconnects the substring connection units 23. In the above fourth modified example, when the occurrence of an arc is detected, the in-substring connection portion 23 that is a connection portion in the solar cell string 2B is electrically disconnected. Thereby, also in a 4th modification, there exists an effect that it can suppress or eliminate both the serial arc and parallel arc in photovoltaic power generation system 1D by simple structure. Furthermore, in the solar cell string 2B in the fourth modification, an arc is more likely to occur in the inter-substring connection portion 22 than in the sub-string connection portion 23. By electrically disconnecting the sub-string connection portion 23, It is possible to suitably suppress an arc generated in the inter-substring connecting portion 22.

  Here, in the solar power generation system 1D, when one or a plurality of arc detection cutting units 13 detect the occurrence of an arc, all the arc detection cutting units 13 in the solar power generation system 1D connect the intra-substring connection units 23. Disconnect electrically. When all the arc detection cutting parts 13 electrically cut the connection part 23 in a substring when arc generation is detected, the series number of the solar cell modules 11 in each electrically cut substring 21 is This reduces the residual voltage that contributes to the generation of parallel arcs in the solar cell string 2C. Further, in the photovoltaic power generation system 1D, when one or a plurality of arc detection / cutting units 13 detect the occurrence of an arc, only the arc detection / cutting unit 13 that has detected the arc electrically cuts the connection part 23 in the substring. May be.

  FIG. 8 is a schematic configuration diagram illustrating a photovoltaic power generation system according to a fifth modification. As shown in FIG. 8, the photovoltaic power generation system 1E includes a solar cell array 31 in which a plurality of solar cell strings 2C are connected in parallel to each other, a load 3, one terminal of the load 3, and the solar cell array 31. A wiring 34A to be connected and a wiring 34B for connecting the other terminal of the load 3 and the solar cell array 31 to each other are provided. In the solar cell array 31, the plurality of solar cell strings 2C are connected in parallel to each other via wirings 32A and 32B. Each wiring 32A is connected to one terminal of the corresponding solar cell string 2C and to the wiring 34A. Each wiring 32B is connected to the other terminal of the corresponding solar cell string 2C and to the wiring 34B. In the present modification, each wiring 32A and wiring 34A constitute a first connection portion 4A, and each wiring 32B and wiring 34B constitute a second connection portion 5A. Therefore, one terminal of each solar cell string 2C and one terminal of the load 3 are connected via the first connection portion 4A, and the other terminal of each solar cell string 2C and the other terminal of the load 3 are connected. Are connected via the second connecting portion 5A. The first connection portion 4A and the second connection portion 5A may include a backflow prevention diode, a fuse element, or a disconnector. FIG. 8 shows an example in which a backflow prevention diode 33 is connected in series to each wiring 32A in the first connection portion 4A.

  Each of the plurality of solar cell strings 2 </ b> C includes a plurality of solar cell modules 11, a plurality of in-string connection portions 12, and an arc detection cutting unit 13. When the arc detection cutting unit 13 detects that an arc has occurred in the solar power generation system 1E, at least one of the string connection portions 12 of the plurality of solar cell strings 2C is electrically disconnected by the arc detection cutting unit 13. The Also in the above fifth modified example, both the series arc and the parallel arc in the photovoltaic power generation system 1E are suppressed or reduced by a simple configuration in which the in-string connection portion 12 is electrically disconnected when the occurrence of an arc is detected. There exists an effect that it can be eliminated.

  The arc detection cutting unit 13 in the solar power generation system 1E may be the cutting unit 15. In this case, an arc detection unit that controls the cutting unit 15 may be installed independently of the solar cell array 31. For example, you may have the arc detection part 14A which observes the direct current which flows through the load 3, like the solar power generation system 1F in a 6th modification (refer FIG. 9). In this case, the arc detection unit 14A controls the cutting unit 15 installed in each solar cell string 2C. When the arc detection unit 14A detects the occurrence of an arc, it can control all the cutting units 15 at the same time. Further, when the arc detection unit 14A detects the occurrence of an arc, the arc detection unit 14A may control each cutting unit 15 individually without controlling all the cutting units 15 at the same time. When all of the cutting parts 15 electrically disconnect the in-string connecting parts 12 when the arc detecting part 14A detects the occurrence of an arc, a parallel arc between the first connecting part 4A and the second connecting part 5A, It is possible to effectively suppress both the series arc in the first connection portion 4A or the second connection portion 5A.

  You may have the arc detection part 16A which observes the direct-current voltage applied to the load 3, like the solar power generation system 1G (refer FIG. 10) in a 7th modification. In this case, the arc detection unit 16A controls the cutting unit 15 installed in each solar cell string 2C. The arc detection unit 16A controls the cutting units 15 at the same time, but may control them individually. Moreover, you may have 17 A of arc detection parts containing arc detection part 14A, 16A like the solar power generation system 1H (refer FIG. 11) in an 8th modification.

  FIG. 12 is a schematic configuration diagram illustrating a photovoltaic power generation system according to a ninth modification. As shown in FIG. 12, the photovoltaic power generation system 1I includes a solar cell array 31A in which solar cell strings 2D, 2E, and 2F are connected in parallel to each other. The solar cell string 2 </ b> D includes a plurality of solar cell modules 11, a plurality of in-string connection portions 12, and an arc detection cutting unit 13. The solar cell string 2 </ b> E has substrings 41 </ b> A and 41 </ b> B and an intersubstring connecting portion 22. The solar cell string 2F has a plurality of substrings 42 and a plurality of substring connecting portions 22.

  Each of the substrings 41 </ b> A, 41 </ b> B, 42 includes a plurality of solar cell modules 11, a plurality of substring connection portions 23, and an arc detection cutting portion 13. Further, the number of the plurality of solar cell modules 11 in the substring 41A is different from the number of the plurality of solar cell modules 11 in the substring 41B. Thus, even if the configurations of the solar cell strings 2D to 2F included in the solar cell array 31A are different from each other, the connection within the substring 23 is electrically disconnected when the generation of the arc is detected. With a simple configuration, there is an effect that both the series arc and the parallel arc in the photovoltaic power generation system 1E can be suppressed or eliminated. The solar cell strings 2D, 2E, and 2F may each include a backflow prevention diode or an overcurrent prevention DC fuse element.

  The arc detection cutting unit 13 in the solar power generation system 1I may be the cutting unit 15. In this case, the arc detection part which controls the cutting part 15 may be installed independently of the solar cell array 31A. For example, as in the photovoltaic power generation system 1J in the tenth modification (see FIG. 13), the arc detector 14B that observes the DC current waveform flowing through the load 3 and the DC voltage waveform applied to the load 3 are observed. You may have the arc detection part 17B containing the arc detection part 16B. In this case, the arc detection unit 17B controls the cutting unit 15 installed in the solar cell string 2D and the substrings 41A, 41B, and 42. When the arc detection unit 17B detects the occurrence of an arc, it can control all the cutting units 15 simultaneously. Moreover, the arc detection part 17B may control separately, without controlling all the cutting parts 15 simultaneously, when an arc generation | occurrence | production is detected. When all the cutting parts 15 electrically disconnect the connection part 12 in a string or the connection part 23 in a substring when the arc detection part 17B detects the occurrence of an arc, the first connection part 4A and the second connection part 5A. It is possible to effectively suppress both the parallel arc between and the series arc in the first connection portion 4A or the second connection portion 5A.

(Second Embodiment)
Next, a second embodiment will be described. In the description of the present embodiment, differences from the first embodiment will be mainly described.

  FIG. 14 is a schematic configuration diagram illustrating a photovoltaic power generation system according to the second embodiment. As shown in FIG. 14, in the solar power generation system 1K, a first solar cell array 51 in which a plurality of first solar cell strings 61 are connected in parallel to each other and a plurality of second solar cell strings 62 are connected in parallel to each other. The second solar cell array 52, the wiring 66 that connects the first solar cell array 51 and the second solar cell array 52 in series, the load 3, one terminal of the load 3, and the first solar cell array 51 are connected to each other. A wiring 65A to be connected and a wiring 65B to connect the other terminal of the load 3 and the second solar cell array 52 to each other are provided.

  The first solar cell array 51 has wirings 63A and 63B, and the plurality of first solar cell strings 61 are connected in parallel to each other through the wirings 63A and 63B. Each wiring 63A is connected to one terminal of the corresponding first solar cell string 61 and to the wiring 65A. Each wiring 63 </ b> B is connected to the other terminal of the corresponding first solar cell string 61 and to the wiring 66.

  The second solar cell array 52 has wirings 63C and 63D, and the plurality of second solar cell strings 62 are connected in parallel to each other via the wirings 63C and 63D. Each wiring 63 </ b> C is connected to one terminal of the corresponding second solar cell string 62 and to the wiring 66. Each wiring 63D is connected to the other terminal of the corresponding second solar cell string 62 and to the wiring 65B.

  Each of the first solar cell string 61 and the second solar cell string 62 includes a plurality of solar cell modules 11 and an in-string connection portion 12 that connects the solar cell modules 11 in series.

  In this embodiment, each wiring 63A and wiring 65A constitute a first connection portion 4B, and each wiring 63D and wiring 65B constitute a second connection portion 5B. Each wiring 63B, each wiring 63C, and wiring 66 constitute an inter-array connection portion 53. The first connection portion 4B and the second connection portion 5B may include a backflow prevention diode, a fuse element, or a disconnector. FIG. 14 shows an example in which a fuse element 64 is connected to each wiring 63A in the first connection portion 4B. The fuse element 64 is an element that electrically disconnects itself when an excessive current flows through the corresponding first solar cell string 61 or second solar cell string 62, for example.

  The inter-array connection portion 53 may include a backflow prevention diode or a fuse element. FIG. 14 shows an example in which a fuse element 64 is connected to each wiring 63C. Further, the inter-array connection part 53 may be shorter than the first connection part 4B and the second connection part 5B. Further, the arc detection cutting unit 13 is provided in the wiring 66 of the inter-array connection unit 53. In the second embodiment as well, both the series arc and the parallel arc in the photovoltaic power generation system 1K are suppressed by a simple configuration in which the inter-array connection portion 53 is electrically disconnected when the occurrence of the arc is detected. Alternatively, the same effect as the first embodiment can be achieved. Further, in the photovoltaic power generation system 1K, parallel arcs are more likely to occur in the first and second connection parts 4B and 5B than in the inter-array connection part 53. By electrically disconnecting the inter-array connection part 53, the first It becomes possible to suppress the parallel arc generated in the first and second connection portions 4B and 5B.

  FIG. 15: is a schematic block diagram which shows the solar energy power generation system which concerns on the modification of 2nd Embodiment. As shown in FIG. 15, in the solar power generation system 1 </ b> L, the plurality of first solar cell strings 61 </ b> A and the plurality of second solar cell strings 62 </ b> A have the arc detection cutting unit 13. Further, the length of the in-string connecting portion 12 is shorter than the length of the inter-array connecting portion 53. In this case, in addition to the first connection portion 4B and the second connection portion 5B, the inter-array connection portion 53 is set as an arc generation target connection portion.

  In the photovoltaic power generation system 1L, a parallel arc is more likely to occur in the first and second connection parts 4B and 5B and the inter-array connection part 53 than in the in-string connection part 12, but the in-string connection part 12 is electrically disconnected. By doing so, it becomes possible to suppress the parallel arc generated in the first and second connection portions 4B and 5B and the inter-array connection portion 53. Therefore, also in the above modification, both the series arc and the parallel arc in the photovoltaic power generation system 1L are suppressed or eliminated by a simple configuration in which the connection part 12 in the string is electrically disconnected when the occurrence of the arc is detected. The same effect as the second embodiment can be achieved.

(Third embodiment)
Next, a third embodiment will be described. In the description of the present embodiment, differences from the first embodiment and the second embodiment will be mainly described.

  FIG. 16 is a schematic configuration diagram illustrating a photovoltaic power generation system according to the third embodiment. As illustrated in FIG. 16, the photovoltaic power generation system 1M includes a solar cell array 31B in which a plurality of solar cell strings 2G, 2H, and 2I are connected in parallel to each other, a load 3, one terminal of the load 3, and a solar cell. A wiring 34A for connecting the array 31B to each other and a wiring 34B for connecting the other terminal of the load 3 and the solar cell array 31 to each other are provided. In the solar cell array 31, the plurality of solar cell strings 2G, 2H, and 2I are connected in parallel to each other via wirings 32A and 32B, as in the fifth modification of the first embodiment. Similarly to the fifth modified example, each wiring 32A and wiring 34A constitute a first connection portion 4A, and each wiring 32B and wiring 34B constitute a second connection portion 5A. .

  Each of the plurality of solar cell strings 2G, 2H, and 2I includes a plurality of solar cell modules 11 and a plurality of in-string connection portions 12. In the solar cell array 31B, the arc detection cutting unit 13 is installed in the wiring 32A in the vicinity of the solar cell string 2G and the wiring 32B in the vicinity of the solar cell string 2H. That is, one arc detection cutting unit 13 is installed at the end of the wiring 32A on the solar cell string 2G side, and the other arc detection cutting unit 13 is installed at the end of the wiring 32B on the solar cell string 2H side. Yes. When one arc detection cutting part 13 detects that an arc has occurred in the photovoltaic power generation system 1M, the first connection part 4A excluding a small part of the wiring 32A from the solar cell string 2G is electrically disconnected. . Moreover, when the other arc detection cutting part 13 detects that the arc generate | occur | produced in the solar power generation system 1M, the 2nd connection part 5A except a very small part of the wiring 32B from the solar cell string 2H electrically cuts. Is done.

  In the solar cell array 31B, the cutting portion 15 is provided in the wiring 32A in the vicinity of the solar cell string 2I. That is, the cutting part 15 is installed at the end of the wiring 32A on the solar cell string 2I side. The cutting unit 15 is connected to an arc detection unit 14C installed on the wiring 34A. When the arc detection unit 14C detects that an arc has occurred in the photovoltaic power generation system 1M, the cutting unit 15 electrically disconnects the first connection unit 4A excluding a small part of the wiring 32A from the solar cell string 2I. The

  As a general arc elimination method when the photovoltaic power generation system 1M as described above does not have the arc detection cutting unit 13 and the cutting unit 15, for example, a method of opening the solar cell strings 2G to 2I from the load 3 (Specifically, the method of electrically disconnecting the first connecting portion 4A and / or the second connecting portion 5A from the load 3) and the method of short-circuiting the solar cell strings 2G to 2I (specifically, the first And a method of connecting the end of the connecting portion 4A on the load 3 side and the end of the second connecting portion 5A on the load 3 side). The arc elimination method described above is generally performed by switching the connection state of the switch in a load 3 such as a power conditioner or in a connection box in which the load 3 or the like can be accommodated. Therefore, when the arc elimination method described above is employed, the first connection portion 4A and the second connection portion 5A are connected to the solar cell strings 2G to 2I.

  Here, the first connection portion 4A and the second connection portion 5A are highly likely to be directly affected by the external environment such as weather, that is, the arc generation target connection portion in which an arc is likely to be generated in the solar power generation system 1M. It is. Therefore, after performing the arc elimination method described above, there is a high possibility that the connection between the solar cell strings 2G to 2I and the arc occurrence location is maintained. In this case, the arc may expand unless appropriate measures are taken according to the type of the generated arc, and there is a possibility that both the series arc and the parallel arc in the photovoltaic power generation system 1M cannot be suppressed or eliminated. is there.

  In contrast, in the photovoltaic power generation system 1M according to the third embodiment, after it is detected that an arc has occurred, the first connection portion 4A and the second connection portion 5A are solar cell strings in the solar cell array 31B. No longer connected to 2G-2I. For this reason, the solar cell strings 2G to 2I as the power generation units can be electrically disconnected from the first connection part 4A or the second connection part 5A having the arc generation point. Therefore, when it is detected that an arc has occurred in the solar power generation system 1M, the first connection portion 4A and the second connection portion 5B are electrically disconnected from the solar cell array 31B, thereby allowing the solar power generation system 1M to Both series arcs and parallel arcs can be suppressed or eliminated. That is, also in this embodiment, there exists an effect equivalent to 1st and 2nd embodiment.

  In the present embodiment, the solar cell string 2 (see FIG. 1) of the first embodiment may be applied instead of the solar cell array 31B. In this case, it is preferable that the arc detection cutting part 13 or the cutting part 15 is installed in the first connection part 4 and the second connection part 5 in the vicinity of the solar cell string 2.

  As mentioned above, although embodiment of this invention was described, this invention is not restricted to the said embodiment and modification, It deform | transformed in the range which does not change the summary described in each claim, or applied to others It may be a thing. For example, the arc detection unit 14 and the cutting unit 15 of the solar power generation system 1A (see FIG. 6A) may be applied instead of the arc detection cutting unit 13 of the solar power generation system 1D (see FIG. 7). Good. For example, instead of the arc detection cutting unit 13 of the solar power generation system 1L (see FIG. 15), the arc detection unit 14B and the cutting unit 15 of the solar power generation system 1J (see FIG. 13) may be applied. . Moreover, you may use together the arc detection cutting part 13, the arc detection part 14, and the cutting part 15 in the solar power generation system 1. FIG.

  In the said embodiment and modification, about the number of the solar cell strings with which a solar power generation system is equipped, the number of the solar cell modules which a solar cell string has, the number of the photovoltaic cells which a solar cell module contains, and the number of solar cell arrays It is not limited and may be one or more. For example, in the solar power generation system 1K (see FIG. 14), in addition to the first solar cell array 51 and the second solar cell array 52, a plurality of other solar cell arrays may be connected in series.

  In the said embodiment and modification, a some arc detection cutting part or a some cutting part may be contained in the solar cell string and the substring. Moreover, the comparison detection part (arc detection part) and the cutting part of the arc detection cutting part 13 in the above embodiment and the modification may not necessarily be configured integrally.

  In addition, since the said arc elimination method disconnects the connection part in a string when an arc generation | occurrence | production is detected, it is regarded as the disconnection method of the photovoltaic power generation system which disconnects a solar cell string in order to suppress arc generation. You can also. Moreover, since the detection of an arc and the disconnection of the connection part in a string can be implemented during a driving | operation of a solar power generation system, it can also be understood that the operating method of a solar power generation system includes the said arc elimination method.

  DESCRIPTION OF SYMBOLS 1,1A-1M ... Solar power generation system, 2, 2A-2I ... Solar cell string, 3 ... Load, 4, 4A, 4B ... 1st connection part, 5, 5A, 5B ... 2nd connection part, 11 ... Sun Battery module, 12 ... connection part in string, 13 ... arc detection cutting part, 14, 14A, 14B, 14C, 16, 16A, 16B, 17, 17A, 17B ... arc detection part, 15 ... cutting part, 21, 41A, 41B, 42... Substring, 22... Substring connection portion, 23... Substring internal connection portion, 31, 31 A, 31 B ... Solar cell array, 51 ... First solar cell array, 52.

Claims (8)

A solar cell string having a plurality of solar cell modules, and an in-string connection portion for connecting the solar cell modules in series;
A load to which power generated by the solar cell string is supplied;
A first connecting portion that connects one terminal of the load and one terminal of the solar cell string;
A second connection portion for connecting the other terminal of the load and the other terminal of the solar cell string to each other;
A solar power generation system comprising:
An arc detector for detecting the occurrence of an arc in the solar power generation system;
When the arc detection unit detects the occurrence of the arc, a cutting unit for electrically cutting the connection part in the string in the solar cell string;
A solar power generation system comprising:   2. The photovoltaic power generation system according to claim 1, wherein a length of the in-string connection portion is shorter than a length of the first connection portion and the second connection portion.   The photovoltaic power generation system according to claim 1 or 2, wherein the cutting unit at least electrically cuts the in-string connection unit corresponding to a midpoint of the solar cell string or the vicinity of the midpoint.   The solar power generation system according to any one of claims 1 to 3, wherein the arc detection unit and the cutting unit are arranged in the same in-string connection unit. The solar cell string has a plurality of substrings, and an intersubstring connection part that connects the substrings in series,
Each of the substrings includes a plurality of the solar cell modules, and a connection part in the substring that connects the solar cell modules in series and is shorter than the connection part between the substrings,
The cutting unit, when the arc detection unit detects the occurrence of an arc in the photovoltaic power generation system, at least electrically cuts the connection part in the substring in any of the plurality of substrings. The solar power generation system as described in any one of 1-4.   The solar power generation system as described in any one of Claims 1-5 provided with the solar cell array by which the said some solar cell string was mutually connected in parallel. A first solar cell array in which a plurality of first solar cell strings are connected in parallel to each other;
A second solar cell array in which a plurality of second solar cell strings are connected in parallel to each other;
An inter-array connection for connecting the first solar cell array and the second solar cell array in series with each other;
A load to which power generated by the first solar cell array and the second solar cell array is supplied;
A first connection part for connecting one terminal of the load and the first solar cell array to each other;
A second connection portion for connecting the other terminal of the load and the second solar cell array to each other;
A solar power generation system comprising:
Each of the plurality of first solar cell strings and the plurality of second solar cell strings has a plurality of solar cell modules, and an in-string connection portion that connects the solar cell modules in series,
An arc detector for detecting the occurrence of an arc in the solar power generation system;
When the arc detection unit detects the occurrence of the arc, a cutting unit that electrically disconnects at least one of the connection part in the string and the connection part between the arrays,
A solar power generation system comprising: A solar cell string having a plurality of solar cell modules, and an in-string connection portion for connecting the solar cell modules in series;
A load to which power generated by the solar cell string is supplied;
A first connecting portion that connects one terminal of the load and one terminal of the solar cell string;
A second connection portion for connecting the other terminal of the load and the other terminal of the solar cell string to each other;
A solar power generation system comprising:
An arc detector for detecting the occurrence of an arc in the solar power generation system;
When the arc detection unit detects the occurrence of the arc, a cutting unit that electrically disconnects at least one of the first connection unit and the second connection unit from the solar cell string;
A solar power generation system comprising:

Images