JP6769607B2 - High temperature region extractor - Google Patents

Description

The present invention relates to a high temperature region extraction device.

Conventionally, a technique for detecting a failure of a solar panel is known. For example, in Patent Document 1, the temperature of the solar panel is acquired by installing a temperature detecting means such as thermal paper on the solar panel, and abnormal heat is generated due to an opening failure of the bypass circuit (hereinafter, , Hotspot fever) is described as a method of inspecting whether or not it is generated.
Further, in Patent Document 2, an additional bypass circuit different from the bypass circuit provided in the solar panel is provided, and by adding a temperature sensor to the additional bypass circuit, the bypass circuit provided in the solar panel is opened and failed. A technique is known for detecting the presence or absence of an open failure of a bypass circuit based on a temperature rise of a temperature sensor added to the additional bypass circuit.
Further, in Patent Document 3, by connecting a charged capacitor to a solar panel and discharging it at night, the presence or absence of an open failure of a bypass circuit is detected from changes in voltage at the time of discharge and voltage-current characteristics of the current. The technology to be used is described.
Further, Patent Document 4 describes a technique for detecting the presence or absence of an open failure of a bypass circuit by passing a current through a current source circuit through a solar panel at night and measuring the potential difference between the positive electrode and the negative electrode of the solar panel. Is described.

Japanese Unexamined Patent Publication No. 2001-24204 Japanese Unexamined Patent Publication No. 2013-157456 Japanese Unexamined Patent Publication No. 2011-66320 Japanese Unexamined Patent Publication No. 2014-11427

However, the conventional techniques described in Patent Document 1 and Patent Document 2 detect the temperature of each solar panel when detecting an open failure of the bypass circuit for the already installed solar panel. There were times when means had to be installed. For example, in the conventional technology, when detecting an open failure of a bypass circuit in a mega solar or the like in which a large number of solar panels to be detected are installed, a temperature detecting means must be installed for each of the large number of solar panels. There was a case. In this case, it may be difficult to reduce the time and effort required to detect an open failure of the bypass circuit provided in the solar panel.
Further, in the conventional techniques described in Patent Document 3 and Patent Document 4, it may be required to perform an inspection at night when detecting the presence or absence of an open failure of the bypass circuit of the solar panel. In this case, since nighttime inspection is more difficult than daytime inspection, it may be difficult to reduce the time and effort required to detect an open failure of the bypass circuit of the solar panel with these conventional techniques. It was.
Further, in the conventional techniques described in Patent Documents 3 and 4, even if it is possible to detect the presence or absence of a failure of the solar panel, the failure of the solar panel in which the failure is detected is detected. In some cases, it was difficult to detect the position where the problem occurred.
An object of the present invention is to provide a high temperature region extraction device capable of reducing the trouble of detecting a failure of a bypass circuit included in a solar panel.

One aspect of the present invention is to image an array containing a plurality of strings in which a plurality of clusters in which a diode and one or more cells are connected in parallel are connected in series to show temperature distribution information on the surface of the array. an imaging unit for generating a temperature image of the inspection target region is a specific portion of the array, the power output end of the array, wherein the array voltage cause by the power generation to the power supply voltage in the reverse direction is applied A plurality of images showing a temperature change accompanying the temperature change, the first temperature image captured by the imaging unit at different times, the acquisition unit for acquiring the second temperature image, and the first acquisition unit acquired by the acquisition unit. It is a high temperature region extraction device including a high temperature region extraction unit that extracts a high temperature region from the inspection target region of the array based on the difference between the temperature image and the temperature distribution information shown in the second temperature image. ..

Further, in the high temperature region extraction device of the present invention, the first temperature image is an image before or immediately after the power supply voltage is applied to the power output end of the array , and the first temperature image is the first. The two-temperature image is an image during which the power supply voltage is applied to the power output end of the array or after the power supply voltage is applied for a predetermined time, and the acquisition unit is from the time when the second temperature image is captured. Previously, the first temperature image is acquired.

Further, in the high temperature region extraction device according to the present invention, the imaging unit images at least two clusters of the array and generates the temperature image.

According to the present invention, it is possible to reduce the time and effort required to detect a failure of the bypass circuit included in the solar panel.

It is a schematic diagram which shows an example of the photovoltaic power generation system which is the observation target of the high temperature region extraction apparatus of this embodiment. It is a block diagram which shows an example of the structure of the photovoltaic power generation system which is the observation target of the high temperature region extraction apparatus of this embodiment. It is a schematic diagram which shows an example of the structure of the string of the photovoltaic power generation system. It is a block diagram which shows a detailed example of the structure of the string of the photovoltaic power generation system. It is a schematic diagram which shows an example of the junction box of the photovoltaic power generation system. It is a block diagram which shows an example of the operation of a cluster in a sunny day of a photovoltaic power generation system. It is a block diagram which shows an example of the operation of a string in a sunny day of a photovoltaic power generation system. It is a block diagram which shows an example of the operation of a cluster when the shadow of a photovoltaic power generation system is generated. It is a block diagram which shows an example of the operation of a string when the shadow of a photovoltaic power generation system is generated. It is a block diagram which shows an example of the operation when the bypass diode of a photovoltaic power generation system is open failure, and the shadow of a cluster is generated. It is a schematic diagram which shows an example of the high temperature region extraction apparatus in this embodiment. It is a block diagram which shows an example of the structure of the DC power source and the junction box in this embodiment. It is a block diagram which shows a detailed example of the structure of a string when the DC power source of this embodiment applies a voltage to an array. It is a block diagram which shows a detailed example of the structure of a string when the DC power source in this Embodiment applies a voltage to an array through a junction box. It is a block diagram which shows an example of the structure of the high temperature region extraction apparatus in this embodiment. It is a schematic diagram which shows an example of the 1st temperature image in this embodiment. It is a schematic diagram which shows an example of the difference area in this embodiment. It is a schematic diagram which shows an example of the high temperature region in this embodiment. It is a flow chart which shows an example of the operation of the high temperature region extraction apparatus in this embodiment. It is a block diagram which shows a detailed example of the structure of the string when the shadow is generated when the DC power supply applies a voltage to the array in this embodiment. It is a 1st image which shows an example of the difference area of a modification. It is a second image which shows an example of the difference area of a modification. It is a 3rd image which shows an example of the difference area of a modification.

[Embodiment]
Hereinafter, the configuration of the high temperature region extraction device 1 of the present embodiment will be described with reference to the drawings.
The high temperature region extraction device 1 of the present embodiment includes an imaging unit 110. The image pickup unit 110 takes an image of the temperature distribution on the surface of the array AR and generates an image. Array AR is the name of a configuration in which a plurality of strings ST are connected. The string ST is the name of a configuration in which a plurality of solar cell panels are connected. A solar cell panel is a device that generates electricity when irradiated with light such as solar radiation. The high temperature region extraction device 1 detects a failure of the array AR based on the image generated by the imaging unit 110.
First, the array AR, which is the observation target of the high temperature region extraction device 1, will be described with reference to the drawings.

[Configuration of photovoltaic power generation system SPS]
First, the configuration of the photovoltaic power generation system SPS will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an example of a photovoltaic power generation system SPS which is an observation target of the high temperature region extraction device 1 of the present embodiment.
As shown in FIG. 1, the photovoltaic power generation system SPS includes an array AR, a junction box JB, and a power conditioner PC. The array AR includes a plurality of strings ST. In this example, a case where three string STs are installed on the gantry M will be described. Specifically, a case where the strings ST1, the strings ST2 and the strings ST3 are installed on the gantry M will be described.

As shown in FIG. 1, the array AR and the junction box JB are connected by the wiring WR1. Further, the junction box JB and the power conditioner PC are connected by the wiring WR2. The junction box JB is a device that aggregates the wiring that connects the string ST and the power conditioner PC. As a result, the string ST is supplied to the power conditioner PC via the junction box JB generated by the string ST. In the following description, when wiring WR1 and wiring WR2 are not particularly distinguished, they are collectively referred to as wiring WR.
The power conditioner PC is a device that converts the DC power generated by the array AR into AC power. For example, the power conditioner PC converts the electric power generated by the array AR into commercial 100V used at home or the like. That is, the electric power generated by the array AR is adjusted via the power conditioner PC and converted into electric power used at home or the like.

Next, a detailed configuration of the photovoltaic power generation system SPS will be described with reference to FIG. FIG. 2 is a configuration diagram showing an example of the configuration of the photovoltaic power generation system SPS, which is the observation target of the high temperature region extraction device 1 of the present embodiment. In this example, a case where the photovoltaic power generation system SPS includes a power conditioner PC, a junction box JB, and an array AR will be described.
As shown in FIG. 2, the power conditioner PC, the junction box JB, and the array AR are connected via the wiring WR. Specifically, the terminal TPCP, which is the terminal of the positive electrode of the power conditioner PC, and the terminal TJBP, which is the terminal of the positive electrode of the junction box JB, are connected via the wiring WRP. Further, the terminal TPCN, which is the terminal of the negative electrode of the power conditioner PC, and the terminal TJBN, which is the terminal of the negative electrode of the junction box JB, are connected via the wiring WRN. As a result, the integrated power in the junction box JB is supplied to the power conditioner PC.
In the following description, when the wiring WRP and the wiring WRN are not particularly distinguished, they are described as wiring WR2. Further, in the following description, the terminal TJBP, which is the terminal of the positive electrode of the junction box JB, and the terminal TJBN, which is the terminal of the negative electrode, are collectively referred to as a power output terminal TSP.

[Array AR configuration]
Hereinafter, the configuration of the array AR will be described with reference to FIGS. 2, 3, and 4.
As shown in FIG. 2, in this example, the array AR includes a plurality of strings ST. Specifically, the array AR includes a string ST1, a string ST2, and a string ST3. In the following description, when the strings ST1, the string ST2, and the string ST3 are not particularly distinguished, they are collectively referred to as the string ST.
As shown in FIG. 2, the electric power generated by the string ST is supplied to the power conditioner PC via the junction box JB.
First, the string ST will be described with reference to FIG. 3, and the junction box JB will be described later.

FIG. 3 is a schematic view showing an example of the configuration of the string ST of the photovoltaic power generation system SPS. As shown in FIG. 3, in this example, the string ST includes three cluster CSs. Specifically, the string ST includes cluster CS1, cluster CS2, and cluster CS3. That is, the string ST is the name of a configuration in which a plurality of cluster CSs are connected in series.
Further, in this example, the strings ST1, the string ST2, and the string ST3 shown in FIG. 2 have the same configuration as the string ST shown in FIG.
Hereinafter, the details of the string ST will be described with reference to FIG.

FIG. 4 is a configuration diagram showing a detailed example of the configuration of the string ST of the photovoltaic power generation system SPS. As shown in FIG. 4, the cluster CS1 includes an aggregate cell CLS1 in which a plurality of cells CL are connected in series, and a bypass diode Dp1. Further, the cluster CS2 includes an aggregate cell CLS2 in which a plurality of cell CLs are connected in series, and a bypass diode Dp2. Further, the cluster CS3 includes an aggregate cell CLS3 in which a plurality of cell CLs are connected in series, and a bypass diode Dp3. In the following description, when cluster CS1, cluster CS2, and cluster CS3 are not particularly distinguished, they are collectively referred to as cluster CS. When the bypass diode Dp1, the bypass diode Dp2, and the bypass diode Dp3 are not particularly distinguished, they are collectively referred to as the bypass diode Dp. That is, the cluster CS is a name of a configuration including a plurality of cell CLs and a bypass diode Dp.

The cell CL is a solar cell element. The cell CL generates an amount of electric power corresponding to the amount of irradiation light such as solar radiation. Further, the resistance of the cell CL becomes high when the irradiation light such as solar radiation is small. The bypass diode Dp is a diode that bypasses the current in order to prevent a current from flowing from another cluster CS to the cell CL when the resistance of the cell CL is high due to a small amount of irradiation light such as solar radiation.

In the cluster CS1, the bypass diode Dp1 and the aggregate cell CLS1 in which a plurality of cell CLs are connected in series are connected in parallel. More specifically, the terminal TD1k, which is the cathode terminal of the bypass diode Dp1, and the terminal TCLS1P of the assembly cell CLS1 are connected. Further, the terminal TD1a, which is the anode terminal of the bypass diode Dp1, and the terminal TCLS1N of the assembly cell CLS1 are connected.

Further, in the cluster CS2, the bypass diode Dp2 and the aggregate cell CLS2 in which a plurality of cell CLs are connected in series are connected in parallel. More specifically, the terminal TD2k on the cathode side of the bypass diode Dp2 and the terminal TCLS2P of the assembly cell CLS2 are connected. Further, the terminal TD2a on the anode side of the bypass diode Dp2 and the terminal TCLS2N of the assembly cell CLS2 are connected.
Further, in the cluster CS3, the bypass diode Dp3 and the aggregate cell CLS3 in which a plurality of cell CLs are connected in series are connected in parallel. More specifically, the terminal TD3k on the cathode side of the bypass diode Dp3 and the terminal TCLS3P of the assembly cell CLS3 are connected. Further, the terminal TD3a on the anode side of the bypass diode Dp3 and the terminal TCLS3N of the assembly cell CLS3 are connected.

As shown in FIG. 4, the cluster CS1, the cluster CS2, and the cluster CS3 are connected in series. Specifically, the terminal TCS1N of the cluster CS1 shown in FIG. 4 and the terminal TCS2P of the cluster CS2 are connected. Further, the terminal TCS2N of the cluster CS2 and the terminal TCS3P of the cluster CS3 are connected.
That is, a plurality of cluster CSs in which the bypass diode Dp and one or more cells CL are connected in parallel are connected in series to the string ST.

Returning to FIG. 3, the terminal TCS1P of the cluster CS1 and the terminal TSTP of the string ST are connected. Further, the terminal TCS3N of the cluster CS3 and the terminal TSTN of the string ST are connected.
Returning to FIG. 2, the terminal TST1P of the string ST1 and the terminal TJB1 of the junction box JB are connected via the wiring WR11. Further, the terminal TST2P of the string ST2 and the terminal TJB2 of the junction box JB are connected via the wiring WR12. Further, the terminal TST3P of the string ST3 and the terminal TJB3 of the junction box JB are connected via the wiring WR13. Further, the terminal TST1N of the string ST1, the terminal TST2N of the string ST2, the terminal TST3N of the string ST3, and the terminal TJBCN of the junction box JB are connected via the wiring WR14. In the following description, when the wiring WR11, the wiring WR12, the wiring WR13, and the wiring WR14 are not particularly distinguished, the wiring WR2 is described.

Hereinafter, the junction box JB will be described with reference to FIG.
FIG. 5 is a schematic view showing an example of the junction box JB of the photovoltaic power generation system SPS. As shown in FIG. 5, in this example, the junction box JB includes an output switch OSW, a backflow prevention diode Db, and a string switch SSW according to the number of strings ST included in the array AR.
The output switch OSW is a switch that connects the electric power generated by the string ST to the power conditioner PC. By opening and closing the output switch OSW, the supply of the electric power generated by the string ST to the power conditioner PC is controlled. For example, the output switch OSW is a breaker that prevents the power conditioner PC from being damaged due to a lightning strike or damage to the array AR.

The string switch SSW is a switch that connects the string ST and the output switch OSW. By opening and closing the string switch SSW, the supply of the electric power generated by the string ST to the output switch OSW is controlled. For example, the string switch SSW is a breaker that prevents the power conditioner PC from being damaged due to the damage of the string ST. The junction box JB includes the same number of string switches SSW as the string ST included in the array AR. That is, in this example, the junction box JB includes three string switches SSW. Specifically, the junction box JB includes a string switch SSW1, a string switch SSW2, and a string switch SSW3. In the following description, when the string switch SSW1, the string switch SSW2, and the string switch SSW3 are not particularly distinguished, they are collectively referred to as the string switch SSW.

The string switch SSW and the string ST are connected via a backflow prevention diode Dbf. The backflow prevention diode Dbf is a diode that functions as overcurrent protection caused by a short circuit of the string ST connected to the backflow prevention diode Dbf.

As shown in FIG. 5, the terminal TOSW1 of the output switch OSW is connected to the terminal TJBP of the junction box JB. As a result, the terminal TOSW1 of the output switch OSW is connected to the terminal TPCP of the power conditioner PC via the wiring WRP. Further, the terminal TOSW2 of the output switch OSW is connected to the terminal TJBN. As a result, the terminal TOSW2 of the output switch OSW is connected to the terminal TPCN of the power conditioner PC via the wiring WRN.

Further, the terminal TOSW4 of the output switch OSW is connected to the terminal TJBCN of the junction box JB. As a result, the terminal TOSW4 of the output switch OSW is connected to the terminal TSTN of each string ST included in the array AR via the wiring W14. Specifically, as shown in FIG. 5, the terminal TOSW4, the terminal TST1N, the terminal TST2N, and the terminal TST3N are connected. As a result, the terminal TSTN of the string ST is connected to the terminal TPCN of the power conditioner PC via the junction box JB.

As shown in FIG. 5, the terminal TSSW11 of the string switch SSW1, the terminal TSSW21 of the string switch SSW2, and the terminal TSSW31 of the string switch SSW3 are connected to the terminal TOSW3 of the output switch OSW.
Further, the terminal TSSW12 of the string switch SSW1 and the string ST1 are connected via a backflow prevention diode Dbf1. Specifically, the terminal TSSW12 of the string switch SSW1 and the terminal TDbf1k, which is the cathode terminal of the backflow prevention diode Dbf1, are connected. Further, the terminal TDbf1a, which is the anode terminal of the backflow prevention diode Dbf1, and the terminal TJB1 of the junction box JB are connected.

Further, the terminal TSSW22 of the string switch SSW2 and the string ST2 are connected via a backflow prevention diode Dbf2. Specifically, the terminal TSSW22 of the string switch SSW2 and the terminal TDbf2k, which is the cathode terminal of the backflow prevention diode Dbf2, are connected. Further, the terminal TDbf2a, which is the anode terminal of the backflow prevention diode Dbf2, and the terminal TJB2 of the junction box JB are connected.

Further, the terminal TSSW32 of the string switch SSW3 and the string ST3 are connected via a backflow prevention diode Dbf3. Specifically, the terminal TSSW32 of the string switch SSW3 and the terminal TDbf3k, which is the cathode terminal of the backflow prevention diode Dbf3, are connected. Further, the terminal TDbf3a, which is the anode terminal of the backflow prevention diode Dbf3, and the terminal TJB3 of the junction box JB are connected.

[Normal operation during power generation of array AR]
Hereinafter, the specific operation of the array AR will be described with reference to FIGS. 6 and 7. FIG. 6 is a configuration diagram showing an example of the operation of the cluster CS in fine weather of the photovoltaic power generation system SPS. As shown in FIG. 6, in this example, an example of operation in which the string ST is operating normally and each cell CL included in the string ST is generating electric power by irradiating light such as sunlight. It is a schematic diagram which shows.
The amount of power generated by the collective cell CLS included in the cluster CS is greatly affected by the intensity of solar radiation. In this example, the collective cell CLS is irradiated with sufficient solar light for the collective cell CLS to generate electricity.

As the collective cell CLS3 generates electricity, a current I32 flows through the collective cell CLS3. Specifically, a current I32 flows from the terminal TCLS3N of the collective cell CLS3 in the direction of the terminal TCLS3P via the plurality of cells CL. That is, as shown in FIG. 6, a voltage V13 is generated in the cluster CS3. Specifically, a voltage V13 is generated from the terminal TCS3N of the cluster CS3 in the direction of the terminal TCS3P. More specifically, in the terminal TCS3N of the cluster CS3 and the terminal TCS3P, the potential of the terminal TCS3P is higher.

In this case, a reverse power supply voltage is applied to the bypass diode Dp3. Therefore, the current I31 flowing from the terminal TCS3N of the cluster CS3 flows to the collective cell CLS3 except for a leakage current slightly flowing from the terminal TD3a of the bypass diode Dp3 to the terminal TD3k. However, the leakage current slightly flowing from the terminal TD3a of the bypass diode Dp3 to the terminal TD3k is sufficiently smaller than the current flowing to the assembly cell CLS3. Therefore, most of the current I31 flows to the assembly cell CLS3.

Further, as the collective cell CLS2 generates power, a current I22 flows through the collective cell CLS2. Specifically, a current I22 flows from the terminal TCLS2N of the collective cell CLS2 in the direction of the terminal TCLS2P via the plurality of cells CL. That is, as shown in FIG. 6, a voltage V12 is generated in the cluster CS2. Specifically, a voltage V12 is generated from the terminal TCS2N of the cluster CS2 in the direction of the terminal TCS2P. More specifically, in the terminal TCS2N of the cluster CS2 and the terminal TCS2P, the potential of the terminal TCS2P is higher.

In this case, a reverse power supply voltage is applied to the bypass diode Dp2. Therefore, the current I21 flowing from the terminal TCS2N of the cluster CS2 flows to the collective cell CLS2 except for the leakage current slightly flowing from the terminal TD2a of the bypass diode Dp2 to the terminal TD2k. However, the leakage current slightly flowing from the terminal TD2a of the bypass diode Dp2 to the terminal TD2k is sufficiently smaller than the current flowing to the assembly cell CLS2. Therefore, most of the current I21 flows to the assembly cell CLS2.

Further, as the collective cell CLS1 generates power, a current I12 flows through the collective cell CLS1. Specifically, a current I12 flows from the terminal TCLS1N of the collective cell CLS1 in the direction of the terminal TCLS1P via the plurality of cells CL. That is, as shown in FIG. 6, a voltage V11 is generated in the cluster CS1. Specifically, a voltage V11 is generated from the terminal TCS1N of the cluster CS1 in the direction of the terminal TCS1P. More specifically, in the terminal TCS1N and the terminal TCS1P of the cluster CS1, the potential of the terminal TCS1P is higher.

In this case, a reverse power supply voltage is applied to the bypass diode Dp1. Therefore, the current I11 flowing from the terminal TCS1N of the cluster CS1 flows to the collective cell CLS1 except for a leakage current slightly flowing from the terminal TD1a of the bypass diode Dp1 to the terminal TD1k. However, the leakage current slightly flowing from the terminal TD1a of the bypass diode Dp1 to the terminal TD1k is sufficiently smaller than the current flowing to the assembly cell CLS1. Therefore, most of the current I11 flows to the assembly cell CLS1.

Next, the operation of the entire string ST will be described with reference to FIG. 7. FIG. 7 is a configuration diagram showing an example of the operation of the string ST in fine weather of the photovoltaic power generation system SPS. As described above, in this example, the string ST includes a cluster CS1, a cluster CS2, and a cluster CS3 connected in series. That is, a voltage obtained by adding the voltages applied to the cluster CS1, the cluster CS2, and the cluster CS3 is generated from the terminals TSTN at both ends of the string ST to the terminal TSTP. Specifically, in the string ST, a voltage V1 is generated by adding the voltage V13 applied to the cluster CS3, the voltage V12 applied to the cluster CS2, and the voltage V11 applied to the cluster CS1.
That is, the voltage V1 is indicated by V1 = V11 + V12 + V13. Here, in this example, the cluster CS1, the cluster CS2, and the cluster CS3 have the same configuration, and the voltage V11, the voltage V12, and the voltage V13 have the same voltage. As a result, the voltage V1 is indicated by V1 = V11 × 3.

In the above description, the case where three cluster CSs are connected to the string ST has been described, but the present invention is not limited to this. The string ST may include one or more cluster CSs. That is, the voltage V1 generated by the string ST is indicated by V1 = the number of cluster CSs including the cell CL capable of generating power × the voltage generated by the cluster CS including the cell CL capable of generating power.

[Normal operation when shadows are cast on the array AR]
Hereinafter, the specific operation of the array AR will be described with reference to FIGS. 8 and 9. FIG. 8 is a configuration diagram showing an example of the operation of the cluster CS when the shadow of the photovoltaic power generation system SPS is generated. As shown in FIG. 8, in this example, the strings ST1, the string ST2, and the string ST3 are operating normally. Further, in this example, of each cell CL included in the string ST2, a part of the cell CL generates electricity by irradiating light such as solar radiation, and a part of the cell CL generates electricity due to a cloudy weather or a shadow caused by a shield or the like. It is a schematic diagram which shows an example of the operation when it is not done.

As shown in FIG. 8, in this example, the cluster CS1 and the cluster CS3 are sufficiently irradiated with the light required for power generation. Further, in this example, a part of the cell CL of the aggregate cell CLS2 is not sufficiently irradiated with the light required for power generation due to the influence of the shadow. As a result, some of the aggregate cells CLS2 do not generate electricity. In the following description, the cell CL that does not generate power due to the influence of the shadow will be referred to as a non-power generation cell SCL.

As shown in FIG. 8, the aggregate cell CLS2 includes a cell CL and a non-power generation cell SCL. As a result, the current I22 flowing through the collective cell CLS2 is limited. That is, the resistance of the aggregate cell CLS2 becomes large when the irradiation of light required for power generation is not sufficiently obtained. Therefore, the potential of the terminal TCS2P is lower than that of the terminal TCS2P and the terminal TCS2N of the cluster CS2. Specifically, as shown in FIG. 8, a voltage V12 is generated in the cluster CS2 from the terminal TCS2P in the terminal TCS2N direction.

In this case, a forward power supply voltage is applied to the bypass diode Dp2. Therefore, the bypass diode Dp2 is turned on, and the current I33 flowing from the cluster CS3 to the cluster CS2 passes through the bypass diode Dp2. That is, as shown in FIG. 8, the current indicated by the sum of the current IDp2 passing through the bypass diode Dp2 and the current I22 flowing in the assembly cell CLS2, the current I21, and the current I23 are currents of the same magnitude. ..
Further, the voltage V12 generated by the cluster CS2 when the bypass diode Dp2 is turned on is a voltage having substantially the same magnitude as the ON voltage of the bypass diode Dp. That is, the voltage V12 is V12≈1V.

Next, the operation of the entire string ST will be described with reference to FIG. FIG. 9 is a configuration diagram showing an example of the operation of the string ST when the shadow of the photovoltaic power generation system SPS is generated.
As mentioned above, when the shadow is formed, the voltage V1 generated by the string ST is indicated by V1 = V11 + V13-V12. Here, in this example, the cluster CS1, the cluster CS2, and the cluster CS3 have the same configuration, and the voltage V11 and the voltage V13 have the same voltage value. Here, when the magnitude of the voltage V1 is V1, the magnitude of the voltage V11 is V11, and the magnitude of the voltage V12 is V12, the relationship between V1, V11, and V12 is shown by the equation (1). ..

V1 = V11 × 2-V12 ... (1)

In the above description, the case where three cluster CSs are connected to the string ST has been described, but the present invention is not limited to this. The string ST may include one or more cluster CSs. That is, the voltage V1 applied to the string ST is V1 = the number of cluster CSs including the cell CL capable of generating power × the voltage generated by the cluster CS including the cell CL capable of generating power-the number of cluster CSs including the non-power generation cell SCL. × Indicated by the voltage generated in the cluster CS containing the non-power generation cell SCL. Specifically, the magnitude of the voltage V1 is V1 = the number of cluster CSs including the cell CL capable of generating electricity × the voltage value generated by the cluster CS including the cell CL capable of generating electricity-the cluster CS including the non-power generation cell SCL. It is indicated by the number × the ON voltage value of the bypass diode Dp.

Further, in the above description, the case where the non-power generation cell SCL does not generate power is due to the lack of irradiation light such as solar light has been described, but the present invention is not limited to this. The reason why the non-power generation cell SCL does not generate power may be a failure such as damage to the cell CL itself as well as a lack of irradiation light such as solar radiation.

[Operation when bypass diode Dp open failure and shadow is generated]
Hereinafter, the specific operation of the array AR will be described with reference to FIG. FIG. 10 is a configuration diagram showing an example of operation when the bypass diode Dp of the photovoltaic power generation system SPS is open-failed and the shadow of the cluster CS is formed.
As shown in FIG. 10, in this example, a part of each cell included in the cluster CS2 generates electric power by irradiating light such as solar radiation, and a part generates electric power due to the influence of shadow. It is a schematic diagram which shows an example of the operation when there is not. Further, in this example, the bypass diode Dp2 included in the string ST2 has an open failure. That is, the terminal TD2k of the bypass diode Dp2 and the terminal TD2a are not connected and are in an open state.

As described above, the aggregate cell CLS2 includes a cell CL and a non-power generation cell SCL. As a result, the current I22 flowing through the collective cell CLS2 is limited. That is, the resistance of the aggregate cell CLS2 increases when the irradiation of light required for power generation cannot be obtained.
In the case of this example, as described above, since the terminal TD2k and the terminal TD2a are not connected and are in an open state, the current I33 flowing from the cluster CS3 to the cluster CS2 flows to the collective cell CLS2. That is, when the current I33 flows through the collective cell CLS2 which is a resistor, each cell CL included in the collective cell CLS2 becomes hot.

In the following description, the cell CL in the heat-generating state will be referred to as an abnormal cell ACL. When an abnormal cell ACL occurs in the aggregated cell CLS, the cell CL itself may be damaged. Specifically, if the cell CL is in the abnormal cell ACL state for a long time, the cell CL may be damaged or burned.
The present invention has been made in view of the above problems, and reduces the time and effort required to detect a cluster CS in which the bypass diode Dp is open-failed among the string STs included in the array AR.

[Configuration of high temperature region extraction device 1]
Hereinafter, the configuration of the high temperature region extraction device 1 will be described with reference to FIGS. 11 to 19. FIG. 11 is a schematic view showing an example of the high temperature region extraction device 1 in the present embodiment.
As shown in FIG. 11, the DC power supply PS and each junction box JB are connected by a wiring WR. Further, as shown in FIG. 11, the high temperature region extraction device 1 includes an imaging unit 110. The imaging unit 110 images the array AR and generates a first temperature image P1 and a second temperature image P2. The first temperature image P1 is an image obtained by capturing information showing the temperature distribution on the surface of the array AR before the power supply voltage ApV is applied to the array AR from the DC power supply PS via the junction box JB. The second temperature image P2 is an image obtained by capturing information showing the temperature distribution on the surface of the array AR after the power supply voltage ApV is applied to the array AR from the DC power supply PS via the junction box JB.
Hereinafter, the change in the surface temperature of the array AR due to the application of the DC power supply PS to the array AR via the junction box JB will be described with reference to the drawings.

Next, the connection between the DC power supply PS and the junction box JB will be described with reference to FIG. FIG. 12 is a configuration diagram showing an example of the configuration of the DC power supply PS and the junction box JB in the present embodiment.
As shown in FIG. 12, the junction box JB and the DC power supply PS are connected via the wiring WR2. Specifically, the terminal TPSN, which is the terminal of the negative electrode of the DC power supply PS, and the terminal TJBP, which is the terminal of the positive electrode of the junction box JB, are connected via the wiring WRP. Further, the terminal TPSP, which is the terminal of the positive electrode of the DC power supply PS, and the terminal TJBN, which is the terminal of the negative electrode of the array AR, are connected via the wiring WRN.

As a result, the DC power supply PS applies a voltage in the direction opposite to the voltage generated by the array AR described above. Specifically, a power supply voltage ApV is applied to the string ST1 from the terminal TST1P to the terminal TST1N. More specifically, in the terminal TST1P of the string ST1 and the terminal TST1N, the potential of the terminal TST1N is higher. Further, a power supply voltage ApV is applied to the string ST2 from the terminal TST2P to the terminal TST2N. More specifically, in the terminal TST2P of the string ST2 and the terminal TST2N, the potential of the terminal TST2N is higher. Further, a power supply voltage ApV is applied to the string ST3 from the terminal TST3P to the terminal TST3N. More specifically, in the terminal TST3P of the string ST3 and the terminal TST3N, the potential of the terminal TST3N is higher.

[Application of voltage from DC power supply PS: Operation when array AR is normal]
Next, with reference to FIG. 13, the operation of the string ST when the DC power supply PS applies a voltage to the array AR via the junction box JB will be described. FIG. 13 is a configuration diagram showing a detailed example of the configuration of the string ST when the DC power supply PS in the present embodiment applies a voltage to the array AR.
As shown in FIG. 13, in this example, each bypass diode Dp included in the cluster CS1, the cluster CS2, and the cluster CS3 is operating normally. Further, a power supply voltage ApV is applied from the DC power supply PS from the terminal TCS1P of the cluster CS1 connected to the terminal TSTP of the string ST to the terminal TCS3N of the cluster CS3 connected to the terminal TSTN of the string ST. Specifically, the potential of the terminal TCS3N is higher than that of the terminal TCS1P of the cluster CS1 and the terminal TCS3N of the cluster CS3.
Further, in this example, the collective cell CLS included in the cluster CS is irradiated with sufficient solar light for the collective cell CLS to generate power.

As shown in FIG. 13, the current I31 flows into the cluster CS3 as the power supply voltage ApV is applied from the DC power supply PS. As shown in FIG. 13, the potential of the terminal TCS3N is higher than that of the terminal TCS3N and the terminal TCS3P of the cluster CS3. As a result, a forward voltage is applied to the bypass diode Dp3. That is, the current I31 passes through the bypass diode Dp3 and the assembly cell CLS3. Further, as described above, as the collective cell CLS3 generates power, a current I32 flows through the collective cell CLS3. Specifically, a current I32 flows from the terminal TCLS3N of the collective cell CLS3 in the direction of the terminal TCLS3P via the plurality of cells CL. That is, as shown in FIG. 13, the magnitude of the current I33 flowing from the cluster CS3 to the cluster CS2 is I33, the magnitude of the current I31 is I31, the magnitude of the current I32 is I32, and the magnitude of the current IDp3 is IDp3. If so, the relationship between I31, I32, I33, and IDp3 is shown by the equation (2).

I31 = I33 = IDp3 + I32 ... (2)

As shown in FIG. 13, the current I31 flows into the cluster CS3 as the power supply voltage ApV is applied from the DC power supply PS. As shown in FIG. 13, the potential of the terminal TCS3N is higher than that of the terminal TCS3N and the terminal TCS3P of the cluster CS3. As a result, a forward voltage is applied to the bypass diode Dp3. That is, the current I31 passes through the bypass diode Dp3 and the assembly cell CLS3. That is, when the magnitude of the current I31 shown in FIG. 13 is I31 and the magnitude of the current IDp3 passing through the bypass diode Dp3 is IDp3, the relationship between IDp3 and I31 is shown by the equation (3).

I31 = IDp3 + I32 ... (3)

As shown in FIG. 13, as the power supply voltage ApV is applied from the DC power supply PS, the current I21 flows into the cluster CS2 from the cluster CS3. That is, as shown in FIG. 13, when the magnitude of the current I21 is I21, the relationship between I21 and I31 is shown by the equation (4).

I21 = I31 ... (4)

Further, as shown in FIG. 13, the potential of the terminal TCS2N is higher than that of the terminal TCS2N and the terminal TCS2P of the cluster CS2. As a result, a forward voltage is applied to the bypass diode Dp2. That is, the current I21 passes through the bypass diode Dp2 and the assembly cell CLS2. That is, when the magnitude of the current I21 shown in FIG. 13 is I21 and the magnitude of the current IDp2 passing through the bypass diode Dp2 is IDp2, the relationship between I21, IDp2, and I22 is shown by the equation (5). Is done.

I21 = IDp2 + I22 ... (5)

Further, as described above, as the collective cell CLS2 generates power, a current I22 flows through the collective cell CLS2. Specifically, a current I22 flows from the terminal TCLS2N of the collective cell CLS2 in the direction of the terminal TCLS2P via the plurality of cells CL. That is, as shown in FIG. 13, when the magnitude of the current I23 flowing from the cluster CS2 to the cluster CS1 is I23 and the magnitude of the current passing through the bypass diode Dp2 is IDp2, the relational expression between I23, IDp2, and I22. Is represented by equation (6).

I23 = IDp2 + I22 ... (6)

As shown in FIG. 13, as the power supply voltage ApV is applied from the DC power supply PS, the current I11 flows into the cluster CS1 from the cluster CS2. That is, as shown in FIG. 13, when the magnitude of the current I11 is I11, the relationship between I11 and I21 is shown by the equation (7).

I11 = I21 ... (7)

Further, as shown in FIG. 13, the potential of the terminal TCS1N is higher than that of the terminal TCS1N and the terminal TCS1P of the cluster CS1. As a result, a forward voltage is applied to the bypass diode Dp1. That is, the current I11 passes through the bypass diode Dp1. That is, when the magnitude of the current I11 shown in FIG. 13 is I11, the magnitude of the current I12 is I12, and the magnitude of the current IDp1 passing through the bypass diode Dp1 is IDp1, the relationship between IDp1 and I11 is It is represented by the formula (8).

I11 = IDp1 + I12 ... (8)

Further, as described above, as the collective cell CLS1 generates power, a current I12 flows through the collective cell CLS1. Specifically, a current I11 flows from the terminal TCLS1N of the collective cell CLS1 in the direction of the terminal TCLS1P via the plurality of cells CL. That is, as shown in FIG. 13, when the magnitude of the current I13 flowing out of the cluster CS1 is I13 and the magnitude of the current I11 flowing into the cluster CS1 is I11, the relational expression between I13, I11, and I12 is , Expressed by equation (9).

I13 = I11 = IDp1 + I12 ... (9)

That is, the relationship of each current flowing through the string ST is expressed by the equation (10).

I31 = I33 = I21 = I23 = I11 = I13 ... (10)

As a result, as described above, the operation when the string ST is operating normally and each cell CL included in the string ST is generating electric current due to the irradiation of light such as solar light, and each cluster CS. When each bypass diode Dp provided in the above is operating normally and the power supply voltage ApV is applied to the string ST from the DC power supply PS, the currents I11, current I12, current I13, and current I21 flowing through each cluster CS The directions of the current I22, the current I23, the current I31, the current I32, and the current I33 are the same. On the other hand, the operation when the string ST is operating normally and each cell CL of the string ST is generating electric power by irradiating light such as solar radiation, and each of the cluster CSs. When the bypass diode Dp is operating normally and the power supply voltage ApV is applied to the string ST from the DC power supply PS, the polarities of the applied voltages V11, voltage V12, and voltage V13 are reversed.

That is, in the operation when the string ST is operating normally and each cell CL included in the string ST is generating electric power by irradiating light such as solar radiation, the string ST is a power generation element. On the other hand, in the operation when each bypass diode Dp included in each cluster CS is operating normally and the power supply voltage ApV is applied to the string ST from the DC power supply PS, the string ST is a load.

[Application of voltage from DC power supply PS: Operation when bypass diode Dp fails]
Hereinafter, the operation of the string ST when the DC power supply PS applies a voltage to the array AR via the junction box JB will be described with reference to FIG. FIG. 14 is a configuration diagram showing a detailed example of the configuration of the string ST when the DC power supply PS in the present embodiment applies a voltage to the array AR via the junction box JB.
As shown in FIG. 14, in this example, the bypass diode Dp2 included in the cluster CS2 has an open failure. That is, the terminal TD2k of the bypass diode Dp2 and the terminal TD2a are not connected and are in an open state.
Further, in this example, the collective cell CLS included in the cluster CS is irradiated with sufficient solar light for the collective cell CLS to generate power.

Here, since only the configuration of the cluster CS2 is different between the example of the configuration of the string ST shown in FIG. 13 and the example of the configuration of the string ST shown in FIG. 14, the description of the cluster CS1 and the cluster CS3 will be omitted. Hereinafter, the operation of the cluster CS2 will be described in detail with reference to FIG.

As shown in FIG. 14, as the power supply voltage ApV is applied from the DC power supply PS, the current I21 flows into the cluster CS2 from the cluster CS3. As described above, in this example, the terminal TD2k and the terminal TD2a are in the open state. That is, the current I21 flowing from the cluster CS3 flows into the collective cell CLS2. Here, when the magnitude of the current I21 is I21 and the magnitude of the current I22 is I22, the relationship between I21 and I22 is expressed by the equation (11).

I22 = I21 ... (11)

As shown in FIG. 14, as the power supply voltage ApV is applied from the DC power supply PS, the potential of the terminal TCS2N becomes higher than that of the terminal TCS2N and the terminal TCS2P of the cluster CS2. As a result, the voltage V12 is applied from the terminal TCLS2P of the collecting cell CLS2 in the terminal TCLS2N direction.
Here, in the following description, the power consumed by the collective cell CLS2 will be referred to as the power PW2. In this case, since the voltage V12 is applied to each cell CL included in the aggregate cell CLS2, when the magnitude of the power PW2 is PW2 and the magnitude of the voltage V12 applied to the aggregate cell CLS2 is V12, it is PW2. , The relationship between V12 and I22 is expressed by equation (12).

PW2 = V12 × I22 ... (12)

As shown in the formula (12), the power PW2 changes according to the magnitude of the voltage V12 and the current I22. The larger the value of the power PW2, the larger the power consumed by the cluster CS2. That is, the larger the value of the power PW2, the higher the temperature of the cluster CS2.

Here, when the bypass diode Dp2 is connected, a voltage V12, which is a forward voltage, is applied to the bypass diode Dp2. As a result, the bypass diode Dp2 is turned on. That is, the voltage V12 is suppressed by the ON voltage of the bypass diode Dp2. In this example, the ON voltage of the bypass diode Dp2 is less than 1V. That is, as the voltage V12 is suppressed to less than 1V, the power PW2 shows a small value as compared with the case where the bypass diode Dp2 is not connected. That is, when the bypass diode Dp2 is connected, the cluster CS2 does not become hot.

On the other hand, when the bypass diode Dp2 is not connected, the voltage V12 is applied to the collective cell CLS2. As a result, unlike the case where the bypass diode Dp2 is applied, the voltage V12 is not suppressed by the ON voltage of the bypass diode Dp2. That is, the power PW2 shows a large value as compared with the case where the bypass diode Dp2 is connected. That is, when the bypass diode Dp2 is not connected, the cluster CS2 becomes hot.

That is, by applying the power supply voltage ApV from the DC power supply PS to the array AR via the junction box JB, the surface of the array AR caused by the bypass diode Dp failure rises in temperature regardless of the presence or absence of light emitted to the array AR. It is possible to detect the area where the light is flowing.

The power supply voltage ApV applied from the DC power supply PS described above to the array AR via the junction box JB is ApV = the number of cluster CSs including the cell CL capable of generating power × the voltage generated in the cluster CS including the cell CL capable of generating power. + Any voltage value may be used as long as it satisfies the condition of the number of cluster CSs including the non-power generation cell SCL × the voltage generated in the cluster CS including the non-power generation cell SCL.

Hereinafter, the configuration of the high temperature region extraction device 1 will be described with reference to FIG. FIG. 15 is a configuration diagram showing an example of the configuration of the high temperature region extraction device 1 in the present embodiment.
As shown in FIG. 15, the high temperature region extraction device 1 includes a control unit 100, an imaging unit 110, and a storage unit 120.
The imaging unit 110 images the array AR before the DC power supply PS applies the power supply voltage ApV to the string ST, and generates a first temperature image P1 showing the temperature distribution information on the surface of the imaged array AR. Further, the imaging unit 110 images the array AR after the DC power supply PS applies the power supply voltage ApV to the string ST, and generates a second temperature image P2 showing the temperature distribution information on the surface of the imaged array AR. The image pickup unit 110 is, for example, an infrared camera. The imaging unit 110 supplies the generated first temperature image P1 and the second temperature image P2 to the control unit 100. In the following description, when the first temperature image P1 and the second temperature image P2 are not particularly distinguished, they are collectively referred to as the temperature image P.

Hereinafter, an example of the array AR imaged in the temperature image P will be described with reference to FIG. FIG. 16 is a schematic view showing an example of the first temperature image P1 in the present embodiment. As shown in FIG. 16, the temperature image P captures the entire array AR. Specifically, the imaging unit 110 images the entire string ST including the cluster CS1, the cluster CS2, and the cluster CS3. That is, in this example, the array AR includes the string ST, and the string ST includes the cluster CS1, the cluster CS2, and the string ST3.
In this example, the inspection target region CAR, which is the detection target region in which the high temperature region extraction device 1 extracts whether or not the temperature has risen, is the entire array AR imaged on the temperature image P.

In this example, after the imaging unit 110 images the array AR and images the first temperature image P1, the power supply voltage ApV is applied to the array AR from the DC power supply PS. That is, in this example, the second temperature image P2 is generated after the imaging unit 110 generates the first temperature image P1. That is, the imaging unit 110 generates the first temperature image P1 and the second temperature image P2 at different times.

In the above description, the case where the inspection target region CAR is the entire array AR imaged on the temperature image P has been described, but the present invention is not limited to this. A plurality of array ARs may be imaged in the temperature image P. In this case, the high temperature region extraction device 1 may detect the position of the imaged array AR, the position of the inspection target region CAR, and the like based on the array AR imaged on the temperature image P by a known method. ..

Returning to FIG. 15, the threshold information TH is stored in the storage unit 120. The threshold information TH is information indicating the value of the temperature at which it is determined that the bypass diode Dp has failed when the surface temperature of the array AR rises due to the open failure of the bypass diode Dp.

The control unit 100 includes a CPU (Central Processing Unit), and includes an acquisition unit 101, a difference region extraction unit 102, and a high temperature region extraction unit 103.
The acquisition unit 101 acquires the first temperature image P1 and the second temperature image P2 from the image pickup unit 110. The acquisition unit 101 supplies the acquired first temperature image P1 and the second temperature image P2 to the difference region extraction unit 102.

The difference region extraction unit 102 is the temperature distribution of the surface temperature of the array AR shown in the first temperature image P1 and the second temperature image P2 based on the acquired first temperature image P1 and the second temperature image P2. The difference region DAR, which is the region where the difference occurs, is extracted.

Next, an example of the difference region DR extracted by the difference region extraction unit 102 will be described with reference to FIG. FIG. 17 is a schematic diagram showing an example of the difference region DA in this embodiment.
In this example, of the strings ST included in the array AR, the bypass diode Dp2 of the cluster CS2 has an open failure. That is, the temperature distribution information on the surface of the array AR shown in the second temperature image P2 is higher in the first temperature image P1 and the second temperature image P2 due to the open failure of the bypass diode Dp2. .. That is, as shown in FIG. 16, the difference region extraction unit 102 extracts the entire array AR imaged in the first temperature image P1 and the second temperature image P2 as the difference region DAT.
Returning to FIG. 15, the difference region extraction unit 102 supplies the information indicating the extracted difference region DAR to the high temperature region extraction unit 103.

The high temperature region extraction unit 103 acquires information indicating the difference region DAR from the difference region extraction unit 102. The high temperature region extraction unit 103 extracts the high temperature region HAR based on the difference region DA R and the threshold information TH. The high temperature region HAR is a region of the inspection target region CAR in which the temperature of the surface of the array AR is higher than the temperature indicated by the threshold information TH due to the opening failure of the bypass diode Dp. For example, in the high temperature region extraction unit 103, among the temperature distributions shown in the second temperature image P2, the temperature distribution in the region of the array AR indicated by the difference region HAR is higher than the threshold information TH stored in the storage unit 120. Is extracted as a high temperature region HAR.

In this example, the case where the high temperature region extraction unit 103 extracts the high temperature region HAR by comparing the temperature distribution information shown in the second temperature image P2 with the threshold information TH has been described, but the present invention is limited to this. I can't. The high temperature region extraction unit 103 may extract the high temperature region HAR based on the difference image showing the difference between the temperature distribution information shown in the first temperature image P1 and the second temperature image P2.

Hereinafter, an example of the high temperature region HAR will be described with reference to FIG. FIG. 18 is a schematic diagram showing an example of a high temperature region HAR in this embodiment.
As described above, in this example, the bypass diode Dp2 of the cluster CS2 included in the string ST has an open failure. As a result, the temperature of the cluster CS2 becomes higher than that of the cluster CS1 and the cluster CS3. The high temperature region extraction unit 103 extracts a region showing a temperature higher than the threshold information TH from the region of the array AR indicated by the difference region DA as the high temperature region HAR. That is, in this example, the high temperature region extraction unit 103 extracts the region of the cluster CS2 shown in FIG. 18 as the high temperature region HAR.

Hereinafter, the operation of the high temperature region extraction device 1 will be described with reference to FIG. FIG. 19 is a flow chart showing an example of the operation of the high temperature region extraction device 1 in the present embodiment.
The imaging unit 110 images the array AR before the DC power supply PS applies the power supply voltage ApV to the array AR, and generates the first temperature image P1 (step S100). The imaging unit 110 supplies the first temperature image P1 to the acquisition unit 101 (step S110). Further, the imaging unit 110 images the array AR after the DC power supply PS applies the power supply voltage ApV to the array AR, and generates a second temperature image P2 (step S120). The imaging unit 110 supplies the generated second temperature image P2 to the acquisition unit 101 (step S130).

The acquisition unit 101 acquires the first temperature image P1 from the imaging unit 110 (step S140). Further, the acquisition unit 101 acquires the second temperature image P2 from the image pickup unit 110 (step S150). The acquisition unit 101 supplies the acquired first temperature image P1 and the second temperature image P2 to the difference region extraction unit 102 (step S160).

The difference region extraction unit 102 acquires the first temperature image P1 and the second temperature image P2 from the acquisition unit 101 (step S170). The difference region extraction unit 102 extracts the difference region DAT from the inspection target region CAR in which the temperature image P is captured (step S180). The difference region extraction unit 102 supplies the extracted difference region DAR to the high temperature region extraction unit 103 (step S190).

The high temperature region extraction unit 103 acquires information indicating the difference region DA among the inspection target region CARs from the difference region extraction unit 102 (step S200). The high temperature region extraction unit 103 reads the threshold information TH from the storage unit 120 (step S210). The high temperature region extraction unit 103 extracts the high temperature region HAR based on the difference region HAR and the threshold information TH (step S220).

As described above, the high temperature region extraction device 1 of the present embodiment includes a control unit 100, an imaging unit 110, and a storage unit 120.
The imaging unit 110 images an array AR in which a plurality of cluster CSs in which a bypass diode Dp and one or more cells CL are connected in parallel are connected in series, and shows a temperature distribution information on the surface of the array AR. Generate image P. The imaging unit 110 supplies the generated temperature image P to the control unit 100.
The control unit 100 includes an acquisition unit 101, a difference region extraction unit 102, and a high temperature region extraction unit 103 as its functional units. The acquisition unit 101 is a plurality of images showing a temperature change accompanying the application of the power supply voltage ApV to the power output terminal TSP of the junction box JB in the inspection target area CAR which is a specific location of the array AR, and is a plurality of images showing each other. The first temperature image P1 and the second temperature image P2 imaged by the imaging unit 110 at different times are acquired. The acquisition unit 101 supplies the acquired first temperature image P1 and the second temperature image P2 to the difference region extraction unit 102.

The difference region extraction unit 102 extracts the difference region DAR based on the difference in the temperature distribution information shown in the first temperature image P1 and the second temperature image P2 acquired by the acquisition unit 101. The difference region extraction unit 102 supplies the extracted difference region DAR to the high temperature region extraction unit 103.
The high temperature region extraction unit 103 extracts the high temperature region HAR based on the threshold information TH from the difference region DR included in the inspection target region CAR of the array AR.

As a result, the high temperature region extraction device 1 of the present embodiment can extract the region where the surface temperature of the array AR is rising due to the failure of the bypass diode Dp, based on the temperature image P captured by the array AR. it can.
In the conventional technique, an increase in the current value of the backflow prevention diode Dbf provided in the junction box JB or an increase in the temperature of the backflow prevention diode Dbf itself is detected as the bypass diode Dp provided in the cluster CS fails to open. As a result, the failure of the array AR was detected for each string ST.

However, in the conventional technique, even if it is possible to detect which string ST has failed among the plurality of string STs included in the array AR, which cluster CS among the string STs has failed. In some cases, it was not possible to reduce the time and effort required to detect the presence. In particular, when a large number of array ARs in which a large number of cluster CSs are included in one string ST are installed as in mega solar or the like, it is not possible to reduce the trouble of detecting the failure of the bypass diode Dp. There was a case.

Further, in the conventional technique, since the failure of the bypass diode Dp is detected by the state of the backflow prevention diode Dbf, information indicating the correspondence between the circuit of the junction box JB connected to the array AR and the position of the array AR is required. There was a case.

According to the high temperature region extraction device 1 of the present embodiment, the first temperature image P1 and the second temperature image P2 before the DC power supply PS applies the power supply voltage ApV to the array AR via the junction box JB by the imaging unit 110. To image. As a result, the high temperature region extraction device 1 can detect the inspection target region CAR in a plane.
By detecting the inspection target area CAR in an area, the failure area of the array AR can be extracted in an area as a high temperature area HAR included in the inspection target area CAR, not for each circuit such as the string ST.
That is, according to the high temperature region extraction device 1 of the present embodiment, it is necessary in the conventional technique to detect the open failure of the bypass diode Dp by planarly extracting the high temperature region HAR based on the temperature image P. It is possible to reduce the time and effort required to install a sensor for detecting the current value or temperature of the backflow prevention diode Dbf.

Further, according to the high temperature region extraction device 1 of the present embodiment, any cluster among the regions of the array AR from which the high temperature region HAR is extracted by surface-extracting the high temperature region HAR based on the temperature image P. It is possible to extract whether the bypass diode Dp has an open failure in the CS.
That is, the high temperature region extraction device 1 of the present embodiment extracts the high temperature region HAR based on the temperature image P, and when detecting an open failure of the bypass diode Dp, the circuit of the junction box JB and the position of the array AR. It is possible to reduce the trouble of using the information indicating the correspondence of.
That is, according to the high temperature region extraction device 1 of the present embodiment, it is possible to reduce the time and effort for detecting the open failure of the bypass diode Dp.

In the above description, the case where the first temperature image P1 is the temperature image P imaged by the imaging unit 110 before the power supply voltage ApV is applied to the power output terminal TSP of the array AR has been described, but the present invention is not limited to this. .. The first temperature image P1 may be the temperature image P immediately after the power supply voltage ApV is applied to the power output terminal TSP of the array AR. Specifically, the first temperature image P1 is captured at any time as long as the temperature image P is captured by the array AR in which the temperature rise of the array AR is small as the power supply voltage ApV is applied. It may be the temperature image P.
That is, if the first temperature image P1 is the temperature image P in which the array AR in which the temperature rise of the array AR is small due to the application of the power supply voltage ApV is imaged, the power is supplied to the power output terminal TSP of the array AR. The number of times the voltage ApV is applied may be a plurality of times.

Further, in the above description, the aggregate cell CLS included in the cluster CS is irradiated with sufficient solar light for the aggregate cell CLS to generate power, and the bypass diode Dp2 included in the cluster CS2 is open-failed. I explained the case, but it is not limited to this.
In the high temperature region extraction device 1 of the present embodiment, the surface of the array AR is affected by the failure of the bypass diode Dp regardless of whether or not each cell included in the cluster CS is irradiated with light such as solar radiation. The region where the temperature is rising can be detected. That is, in the high temperature region extraction device 1, even when a part of the cluster CS included in the high temperature region extraction device 1 is not generating electric power due to the influence of shadow, the bypass diode Dp is open-failed and the array AR It is possible to detect the region where the surface temperature is rising.

[Application of voltage from DC power supply PS: Operation when bypass diode Dp fails and shadows occur]
Hereinafter, the operation of the string ST when the DC power supply PS applies a voltage to the array AR via the junction box JB will be described with reference to FIG. FIG. 20 is a configuration diagram showing a detailed example of the configuration of the string ST when a shadow is generated when the DC power supply PS applies a voltage to the array AR in the present embodiment.
As shown in FIG. 20, in this example, a part of the cells included in the cluster CS2 generates electric power due to the irradiation of light such as solar radiation, and a part of the cells generate electric power due to the influence of shadows. It is a schematic diagram which shows an example of the operation when it is not done. Further, in this example, the bypass diode Dp2 included in the cluster CS2 has an open failure. That is, the terminal TD2k of the bypass diode Dp2 and the terminal TD2a are not connected and are in an open state.

As described above, the aggregate cell CLS2 includes a cell CL and a non-power generation cell SCL. As a result, the current I22 flowing through the collective cell CLS2 is limited. That is, the resistance of the aggregate cell CLS2 increases when the irradiation of light required for power generation cannot be obtained.
In the case of this example, as described above, since the terminal TD2k and the terminal TD2a are not connected and are in an open state, the current I33 flowing from the cluster CS3 to the cluster CS2 flows to the collective cell CLS2. That is, when the current I33 flows through the collective cell CLS2 which is a resistor, each cell CL included in the collective cell CLS2 becomes hot.

That is, by applying the power supply voltage ApV from the DC power supply PS to the array AR via the junction box JB, the surface of the array AR caused by the bypass diode Dp failure rises in temperature regardless of the presence or absence of light emitted to the array AR. It is possible to detect the area where the light is flowing.

The power supply voltage ApV applied from the DC power supply PS described above to the array AR via the junction box JB is ApV = the number of cluster CSs including the cell CL capable of generating power × the voltage generated in the cluster CS including the cell CL capable of generating power. + Any voltage value may be used as long as it satisfies the condition of the number of cluster CSs including the non-power generation cell SCL × the voltage generated in the cluster CS including the non-power generation cell SCL.

As described above, the aggregate cell CLS2 includes a cell CL and a non-power generation cell SCL. As a result, the current I22 flowing through the collective cell CLS2 is limited. That is, the resistance of the aggregate cell CLS2 increases when the irradiation of light required for power generation cannot be obtained.
In the case of this example, as described above, since the terminal TD2k and the terminal TD2a are not connected and are in an open state, the current I33 flowing from the cluster CS3 to the cluster CS2 flows to the collective cell CLS2. That is, when the current I33 flows through the collective cell CLS2 which is a resistor, each cell CL included in the collective cell CLS2 becomes hot.

Further, in the above description, the case where the second temperature image P2 is the temperature image P imaged by the imaging unit 110 after the power supply voltage ApV is applied to the power output terminal TSP of the junction box JB has been described, but the present invention is not limited to this. .. The second temperature image P2 may be the temperature image P in which the power supply voltage ApV is applied to the power output terminal TSP of the junction box JB. Further, the second temperature image P2 may be the temperature image P after the power supply voltage ApV is applied to the power output terminal TSP of the junction box JB for a predetermined time. Specifically, the second temperature image P2 is captured at any time as long as it is the temperature image P in which the array AR has a progress of temperature rise due to the application of the power supply voltage ApV. The temperature image P may be obtained.
That is, if the second temperature image P2 is a temperature image P in which the temperature of the array AR has risen due to the application of the power supply voltage ApV, the second temperature image P2 is on the power output terminal TSP of the array AR. The power supply voltage ApV may be applied a plurality of times.

Further, in the above description, the case where the imaging unit 110 captures the second temperature image P2 after capturing the first temperature image P1 has been described, but the present invention is not limited to this. The first temperature image P1 is a temperature image P in which the array AR in which the temperature rise of the array AR is small due to the application of the power supply voltage ApV is imaged, and the second temperature image P2 is the power supply voltage ApV. If the temperature image P is an image of the array AR in which the temperature of the array AR has been increased due to the application of, the second temperature image P2 may be imaged before the first temperature image P1. ..

As described above, the first temperature image P1 is a temperature image P before or immediately after the power supply voltage ApV is applied to the power output terminal TSP of the junction box JB. Further, the second temperature image P2 is a temperature image P during or after the power supply voltage ApV is applied to the power output terminal TSP of the junction box JB for a predetermined time. The acquisition unit 101 acquires the first temperature image P1 before the time when the second temperature image P2 is captured.

As a result, the high temperature region extraction device 1 of the present embodiment captures the first temperature image P1 in which the temperature rise is small due to the application of the power supply voltage ApV to the power output terminal TSP of the junction box JB. Further, in the high temperature region extraction device 1 of the present embodiment, after the first temperature image P1 is imaged, the temperature of the array AR rises as the power supply voltage ApV is applied to the power output terminal TSP of the junction box JB. A second temperature image P2 is imaged.

Here, a case where the second temperature image P2 is first captured when the first temperature image P1 and the second temperature image P2 are captured will be described as an example. In this case, immediately after the second temperature image P2 is imaged, the temperature of the array AR rises as the power supply voltage ApV is applied to the power output terminal TSP of the array AR. That is, when the first temperature image P1 is imaged, it may take some time until the temperature rise of the array AR becomes small.

That is, according to the high temperature region extraction device 1 of the present embodiment, the temperature rise of the array AR is small by capturing the first temperature image P1 of the first temperature image P1 and the second temperature image P2. The time required to reach the state can be reduced. That is, according to the high temperature region extraction device 1 of the present embodiment, the opening failure of the bypass diode Dp is detected by capturing the first temperature image P1 of the first temperature image P1 and the second temperature image P2. The time to do this can be reduced.

Further, in the above description, the case where the imaging unit 110 images the entire array AR which is the inspection target region CAR has been described, but the present invention is not limited to this. It is sufficient that at least two cluster CSs are imaged in the temperature image P generated by the image capturing unit 110 imaging the array AR.

As described above, the imaging unit 110 images at least two cluster CSs in the array AR and generates a temperature image P.
As a result, the high temperature region extraction device 1 of the present embodiment captures the temperature images P of the two cluster CSs. Therefore, the high temperature region extraction device 1 of the present embodiment can compare the temperature changes of the two cluster CSs due to the application of the power supply voltage ApV to the power output terminal TSP of the array AR. That is, the high temperature region extraction device 1 of the present embodiment can detect the presence or absence of an open failure of the bypass diode Dp by comparing the temperature changes if at least two cluster CSs are imaged. That is, in the high temperature region extraction device 1 of the present embodiment, even if a large number of array ARs are captured, if the temperature image P is such that at least two cluster CSs can be detected, there is an open failure of the bypass diode Dp. Can be detected.
That is, according to the high temperature region extraction device 1 of the present embodiment, it is possible to reduce the time and effort for detecting the open failure of the bypass diode Dp.

<Modification example>
Hereinafter, a modified example according to the embodiment will be described.
In the above-described embodiment, the case where the difference region extraction unit 102 extracts the difference region DAR based on the temperature image P imaged and generated by the imaging unit 110 has been described. In the modified example, the case where the difference region extraction unit 102 extracts the difference region DAR based on the binarized image of the temperature image P will be described.
The same components as those in the above-described embodiment are designated by the same reference numerals and the description thereof will be omitted.

The difference region extraction unit 102 acquires the first temperature image P1 and the second temperature image P2 generated by the imaging unit 110 from the acquisition unit 101. The difference region extraction unit 102 generates a binarized image PB based on the difference between the acquired first temperature image P1 and the second temperature image P2. Specifically, the difference region extraction unit 102 calculates the temperature difference between the pixels of the second temperature image P2 and the pixels of the first temperature image P1 corresponding to the pixels. The pixel of the second temperature image P2 and the pixel of the first temperature image P1 corresponding to the pixel are the pixels of the first temperature image P1 indicating the same position as the position of the array AR imaged in the second temperature image P2. Is. When the calculated temperature difference is equal to or greater than a predetermined threshold value, the difference region extraction unit 102 sets the pixel to "255", and when it is smaller than the predetermined threshold value, sets the pixel to "1" to obtain a binarized image PB. Generate. The predetermined threshold value is a temperature change that occurs in the time from when the imaging unit 110 images the array AR and generates the first temperature image P1 until the next time the array AR is imaged and the second temperature image P2 is generated. It is a value shown, and is a value of a temperature change indicating that the array AR has changed to a high temperature. The difference area extraction unit 102 extracts a region of the binarized image PB in which a plurality of pixels having a value of "255" are adjacent to each other as a difference area DAT. The difference region extraction unit 102 supplies the extracted difference region DAR to the high temperature region extraction unit 103.

[About the difference area of the binarized image (when 30 seconds have passed since the DC power was applied)]
Hereinafter, with reference to FIGS. 21 to 23, details of the difference region extraction unit 102 extracting the difference region DAR based on the binarized image will be described.
FIG. 21 is a first image showing an example of the difference region DA of the modified example.
FIG. 21A shows a first temperature image P1 captured before the DC power supply PS is applied to the array AR, and a second temperature image 30 seconds after the DC power supply PS is applied to the array AR. It is an image G1 which shows an example of the binarized image PB1 generated based on P2. FIG. 21B is an image G2 showing an example of the second temperature image P2 after 30 seconds have passed since the DC power supply PS was applied to the array AR.
In this example, a case where the region FD99 shown in FIGS. 21 (b), 22 (b) and 23 (b) indicates a failed region of the array AR will be described.
As shown in FIG. 21A, the difference region extraction unit 102 generates a binarized image PB1 based on the first temperature image P1 and the second temperature image P2, and the region FD1 which is a region corresponding to the region FD99. Is extracted as the difference region LAR.
When the high temperature region extraction device 1 extracts the difference region DAR based on the binarized image PB, the array is even for a short time (30 seconds in this example) after the DC power supply PS is applied to the array AR. The area corresponding to the failure of AR can be extracted as the difference area DA.

[About the difference area of the binarized image (when 60 seconds have passed since the DC power was applied)]
FIG. 22 is a second image showing an example of the difference region DA of the modified example.
FIG. 22A shows a first temperature image P1 captured before the DC power supply PS is applied to the array AR, and a second temperature image 60 seconds after the DC power supply PS is applied to the array AR. It is an image G3 which shows an example of the binarized image PB2 generated based on P2. FIG. 22B is an image G4 showing an example of the second temperature image P2 after 60 seconds have passed since the DC power supply PS was applied to the array AR.
As shown in FIG. 22A, the difference region extraction unit 102 generates a binarized image PB2 based on the first temperature image P1 and the second temperature image P2, and the region FD2 is a region corresponding to the region FD99. Is extracted as the difference region LAR.

[About the difference area of the binarized image (120 seconds after the DC power supply is applied)]
FIG. 23 is a third image showing an example of the difference region DA of the modified example.
FIG. 23A shows a first temperature image P1 captured before the DC power supply PS is applied to the array AR, and a second temperature image 120 seconds after the DC power supply PS is applied to the array AR. FIG. 5 is an image G5 showing an example of a binarized image PB3 generated based on P2. FIG. 23B is an image G6 showing an example of the second temperature image P2 120 seconds after the DC power supply PS is applied to the array AR.
As shown in FIG. 23A, the difference region extraction unit 102 generates a binarized image PB2 based on the first temperature image P1 and the second temperature image P2, and the region FD3 is a region corresponding to the region FD99. Is extracted as the difference region LAR.

The difference region extraction unit 102 supplies the extracted difference region DAR to the high temperature region extraction unit 103.
In the modified example, the high temperature region extraction unit 103 extracts the difference region DA acquired from the difference region extraction unit 102 as the high temperature region HAR.

As described above, the high temperature region extraction device 1 of the modified example generates a binarized image PB based on the temperature image P imaged by the imaging unit 110 and extracts the difference region DAR.
Here, in the binarized image PB of the high temperature region extraction device 1 of the modified example, the pixels having a temperature higher than the predetermined threshold value are indicated by "255", and the pixels having a temperature lower than the predetermined threshold value are indicated by "1". Shown. As a result, in the temperature image P in the same imaging range and the binarized image PB, the binarized image PB has a smaller amount of image information. When the high temperature region extraction device 1 extracts the difference region DAR based on the binarized image PB having a small amount of image information, the processing is performed as compared with the case where the difference region DA R is extracted based on the temperature image P. Such a load can be reduced.

Further, when the high temperature region extraction device 1 of the modified example extracts the difference region DAR based on the binarized image PB, it takes less time than the case where the difference region DA R is extracted based on the temperature image P. The area corresponding to the failure of the array AR can be extracted as the difference area DA. Therefore, according to the high temperature region extraction device 1 of the modified example, the time required to extract the high temperature region HAR can be shortened.

Further, as described above, in the temperature image P and the binarized image PB, the binarized image PB may have a smaller amount of image information. Further, in the difference region extraction unit 102, among the binarized image PBs in which a plurality of pixels having matching values are adjacent to each other, the pixels showing a temperature higher than the threshold value (in this example, the pixels of “255”) are A plurality of adjacent areas are extracted as a difference area DA. The high temperature region extraction device 1 of the modified example extracts the difference region DAT based on the binarized image PB, as compared with the case where the difference region DA R is extracted based on the temperature image P. It is easy to process.
As a result, the high temperature region extraction device 1 of the modified example can reduce the time required to extract the high temperature region HAR.

Further, as described above, in the temperature image P and the binarized image PB, the binarized image PB may have a smaller amount of image information. Further, as a storage medium for storing an image or the like, the volume of the storage medium may be reduced when the amount of stored information is small. Therefore, the high temperature region extraction device 1 of the modified example can miniaturize the high temperature region extraction device 1 when extracting the difference region DAR based on the binarized image PB.

Further, as described above, in the temperature image P and the binarized image PB, the binarized image PB is a region corresponding to the failure of the array AR in a short time after the DC power supply PS is applied to the array AR. Can be extracted as the difference region LAR. That is, in the case of extracting the difference region DAR based on the temperature image P and the case of extracting the difference region DAR based on the binarized image PB, the latter is the time for applying the DC power supply PS to the array AR. Can be shortened. Here, if the time for applying the DC power supply PS to the array AR can be shortened, the power output by the DC power supply PS may be reduced. In this case, the volume of the DC power supply PS may be reduced.
As a result, when the high temperature region extraction device 1 of the modified example extracts the high temperature region HAR based on the binarized image PB, the high temperature region extraction device 1 is compared with the case where the high temperature region HAR is extracted based on the temperature image P. The extraction device 1 can be miniaturized.

Each part included in the high temperature region extraction device 1 in each of the above embodiments may be realized by dedicated hardware, or may be realized by a memory and a microprocessor.

Each part of the high temperature area extraction device 1 is composed of a memory and a CPU (central processing unit), and a program for realizing the functions of each part of the high temperature area extraction device 1 is loaded into the memory and executed. It may be the one that realizes the function.

Further, a program for realizing the functions of each part included in the high temperature region extraction device 1 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed for processing. May be done. The term "computer system" as used herein includes hardware such as an OS and peripheral devices.

In addition, the "computer system" includes a homepage providing environment (or display environment) if a WWW system is used.
Further, the "computer-readable recording medium" refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, or a CD-ROM, or a storage device such as a hard disk built in a computer system. Further, a "computer-readable recording medium" is a communication line for transmitting a program via a network such as the Internet or a communication line such as a telephone line, and dynamically holds the program for a short period of time. In that case, it also includes the one that holds the program for a certain period of time, such as the volatile memory inside the computer system that becomes the server or client. Further, the above-mentioned program may be a program for realizing a part of the above-mentioned functions, and may be a program for realizing the above-mentioned functions in combination with a program already recorded in the computer system.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment and may be appropriately modified without departing from the spirit of the present invention. it can. The configurations described in each of the above-described embodiments may be combined.

1 ... High temperature region extraction device, 100 ... Control unit, 101 ... Acquisition unit, 102 ... Difference region extraction unit, 103 ... High temperature region extraction unit, 110 ... Imaging unit, 120 ... Storage unit, ACL ... Abnormal cell, ApV ... Power supply voltage , AR ... Array, CAR ... Inspection target area, CL ... Cell, CLS, CLS1, CLS2, CLS3 ... Aggregate cell, CS, CS1, CS2, CS3 ... Cluster, DA ... Difference area, Db, Dbf, Dbf1, Dbf2, Dbf3 ... Backflow prevention diode, Dp, Dp1, Dp2, Dp3 ... Bypass diode, HAR ... High temperature region, JB ... Junction box, M ... Stand, OSW ... Output switch, P, P1, P2 ... Second temperature image, PC ... Power conditioner, PS ... DC power supply, SPS ... Solar power generation system, SSW, SSW1, SSW2, SSW3 ... String switch, ST, ST1, ST2, ST3 ... String, TSP ... Power output terminal, WR, WR1, WR11, WR12, WR13, WR14, WR2, WRN, WRP ... Wiring

Claims (3)

An imaging unit that images an array containing a plurality of strings in which a diode and a cluster in which one or more cells are connected in parallel are connected in series, and generates a temperature image showing temperature distribution information on the surface of the array. When,
The inspection target region is a specific portion of the array, the power output of said array, said array a plurality of images from the voltage generating showing the temperature changes associated with the power supply voltage in the reverse direction is applied by the generator The acquisition unit that acquires the first temperature image and the second temperature image captured by the imaging unit at different times from each other.
A high temperature region extraction unit that extracts a high temperature region from the inspection target region of the array based on the difference between the temperature distribution information shown in the first temperature image and the second temperature image acquired by the acquisition unit. A high temperature region extraction device characterized by being provided with. The first temperature image is
It is an image before or immediately after the power supply voltage is applied to the power output end of the array .
The second temperature image is
An image of the power supply voltage being applied to the power output end of the array or after being applied for a predetermined time.
The acquisition unit
The high temperature region extraction device according to claim 1, wherein the first temperature image is acquired before the time when the second temperature image is captured. The imaging unit
The high temperature region extraction device according to claim 1 or 2, wherein at least two clusters of the array are imaged and the temperature image is generated.