Anomaly detection device and anomaly detection method for solar power generation systems

Abstract

To provide an abnormality detection device for a photovoltaic power generation system that omits a measuring instrument monitoring a current value of a solar cell string itself.SOLUTION: An abnormality detection device 1 for a photovoltaic power generation system comprises: a plurality of solar cell strings 2; a connection box 3 to which the plurality of solar cell strings 2 are connected; a current measurement part 4 which measures a current output from the connection box 3; and an arithmetic part 11 which detects that a solar cell string 2 having decreased in power generation amount is included in the connection box 3, based upon a measurement result of the current measurement part 4.SELECTED DRAWING: Figure 1

Description

Technical Field

[0006] , ,

[0005] , ,

[0001] The present invention relates to an abnormality detection device and an abnormality detection method for a photovoltaic power generation system including a plurality of solar cell strings.

Background Art

[0002] In recent years, photovoltaic power generation systems using natural energy have been widely spread. In a large-scale photovoltaic power generation system, a plurality of solar cell modules are connected in series to form a solar cell string, and further, a plurality of solar cell strings are connected in parallel. In a photovoltaic power generation plant using such a photovoltaic power generation system, when an abnormality that reduces the power generation amount occurs, it is required to quickly detect the problem and prompt a countermeasure. Therefore, an abnormality detection device that determines whether the power generation amount of the photovoltaic power generation system is appropriate has been proposed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The abnormality detection device for a photovoltaic power generation system described in Patent Document 1 includes a current measurement unit that measures output currents of a plurality of solar cell strings, respectively, and a control unit that sets a system initial value, which is a reference value of the output current, and detects an output abnormality of the solar cell string based on the current measurement value acquired from the current measurement unit and the system initial value.

[0005] In the above-described abnormality detection device for a photovoltaic power generation system, since the output currents of a plurality of solar cell strings are measured respectively, there is a problem that the installation cost of the corresponding equipment increases.

[0006] The present invention was made to solve the above problems and aims to provide an abnormality detection device and method for a photovoltaic power generation system that eliminates the need for a measuring instrument to monitor the current value of the solar cell string itself. [Means for solving the problem]

[0007] The abnormality detection device for a photovoltaic power generation system according to the present invention is an abnormality detection device for a photovoltaic power generation system comprising a junction box to which a plurality of solar cell strings are connected, and is characterized by comprising a current measuring unit that measures the current output from the junction box, and a calculation unit that detects, based on the measurement results of the current measuring unit, that the junction box contains a solar cell string whose power generation has decreased.

[0008] In the abnormality detection device for a photovoltaic power generation system according to the present invention, the calculation unit may be configured to calculate a value relating to the decrease in the amount of power output from the junction box based on the measurement results of the current measurement unit, and to detect whether the junction box contains the solar cell string with reduced power output based on the calculated value relating to the decrease in the amount of power output.

[0009] The abnormality detection device for a solar power generation system according to the present invention may be configured to calculate the number of solar cell strings whose power generation has decreased based on a value relating to the decrease in power generation.

[0010] The abnormality detection device for a photovoltaic power generation system according to the present invention is an abnormality detection device for a photovoltaic power generation system comprising a plurality of junction boxes to which a plurality of solar cell strings are connected, and is characterized by comprising a current measuring unit that measures the current output from each of the plurality of junction boxes, and a calculation unit that compares the amount of power generated in the plurality of junction boxes based on the measurement results of the current measuring unit and detects the junction box that contains the solar cell string whose power generation has decreased.

[0011] In the solar power generation system abnormality detection device according to the present invention, the calculation unit may be configured to set the largest of the multiple power generation amounts in the junction boxes as the maximum power generation amount based on the measurement results of the current measurement unit, compare the maximum power generation amount with the power generation amounts of the other junction boxes to calculate a value relating to the decrease in power generation amount of the other junction boxes, and detect that the other junction boxes contain the solar cell string with reduced power generation based on the calculated value relating to the decrease in power generation amount of the other junction boxes.

[0012] The abnormality detection device for a photovoltaic power generation system according to the present invention may be configured to calculate the number of solar cell strings whose power generation has decreased based on a value relating to the decrease in power generation of the other junction boxes.

[0013] In the anomaly detection device for a photovoltaic power generation system according to the present invention, the value relating to the decrease in the power generation amount of the other junction box may be configured to be the ratio of the decrease in the power generation amount of the other junction box to the maximum power generation amount.

[0014] In the anomaly detection device for a photovoltaic power generation system according to the present invention, the calculation unit may be configured to correct for individual differences in each of the multiple connection boxes when comparing the power generation amounts of the multiple connection boxes.

[0015] The abnormality detection device for a solar power generation system according to the present invention may be configured to include a notification unit that notifies the junction box to which the solar cell string with reduced power generation is connected.

[0016] In the abnormality detection device for a photovoltaic power generation system according to the present invention, the junction box may have a fuse corresponding to each of the plurality of solar cell strings, and may be configured to detect the presence of a solar cell string in which the fuse has blown and the amount of power generated has decreased.

[0017] The method for detecting an abnormality in a photovoltaic power generation system according to the present invention is a method for detecting an abnormality in a photovoltaic power generation system including a plurality of solar cell strings and a connection box to which the plurality of solar cell strings are connected, the method including: a current measurement step of causing a current measurement unit to measure a current output from the connection box; and an arithmetic step of causing an arithmetic unit to detect, based on the measurement result of the current measurement unit, that the connection box includes a solar cell string in which the power generation amount has decreased.

Effect of the Invention

[0018] According to the present invention, by measuring the current value of the connection box, an abnormality in the solar cell string can be detected, and a measuring device for monitoring the current value of the solar cell string itself can be omitted to reduce costs.

Brief Description of the Drawings

[0019] [Figure 1] FIG. 1 is a schematic configuration diagram showing an abnormality detection device for a photovoltaic power generation system according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a characteristic diagram showing an example of the power generation amount for each connection box. [Figure 3] FIG. 3 is a flowchart showing the processing flow of the abnormality detection method for a photovoltaic power generation system according to a first embodiment of the present invention. [Figure 4] FIG. 4 is a flowchart showing the processing flow of the abnormality detection method for a photovoltaic power generation system according to a second embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0020] (First Embodiment) Hereinafter, an abnormality detection device 1 for a photovoltaic power generation system according to a first embodiment of the present invention will be described with reference to the drawings.

[0021] FIG. 1 is a schematic configuration diagram showing an abnormality detection device for a photovoltaic power generation system according to a first embodiment of the present invention.

[0022] The abnormality detection device 1 of the photovoltaic power generation system according to the first embodiment of the present invention includes a plurality of solar cell strings 2, a connection box 3 to which the plurality of solar cell strings 2 are connected, a current measurement unit 4 that measures the current output from the connection box 3, and a calculation unit 11 that calculates the power generation amount of the plurality of solar cell strings 2 connected to the connection box 3. The photovoltaic power generation system includes a solar cell string 2, a connection box 3, a current measurement unit 4, a PCS 5 (power conditioner), a load device 6, and a commercial power system 7.

[0023] The solar cell string 2 is configured by connecting a plurality of solar cell modules that generate electricity using sunlight in series, and a plurality of solar cell strings 2 are connected to one connection box 3. In FIG. 1, a configuration in which three solar cell strings 2 are connected to one connection box 3 and three similar connection boxes 3 are provided is shown, but the present invention is not limited to this, and the number of solar cell strings 2 connected to one connection box 3 and the number of connection boxes 3 may be appropriately changed. The PCS 5 appropriately converts the power supplied through the connection box 3 and supplies it to the load device 6 and the commercial power system 7.

[0024] The connection box 3 is provided between the solar cell string 2 and the PCS 5 and serves to connect the two. The connection box 3 has fuses (not shown) corresponding to each of the plurality of solar cell strings 2.

[0025] In a large-scale photovoltaic power generation system, a plurality of solar cell strings 2 are arranged side by side in a vast site. If all of them are directly connected to the PCS 5, the wiring for connection will become long and the number will increase. Therefore, by providing the connection box 3 and aggregating the wiring, it is possible to avoid losses during power transmission.

[0026] A current measurement unit 4 is provided between the junction box 3 and the PCS5, and the current value output from the junction box 3 is transmitted to the monitoring device 10 via the data conversion unit 8. The junction box 3 outputs the combined current of the multiple solar cell strings 2 connected to it. In addition, the voltage value input from the junction box 3 to the PCS5 is measured by the PCS5 and transmitted to the monitoring device 10.

[0027] The monitoring device 10 comprises a calculation unit 11, a notification unit 12, and a storage unit 13. The calculation unit 11 calculates the amount of power generated for each junction box 3 based on the current value transmitted from the data conversion unit 8 and the voltage value transmitted from the PCS 5. The notification unit 12 provides various notifications to the user based on the calculation results from the calculation unit 11. The storage unit 13 stores the current value transmitted from the data conversion unit 8, correction values ​​used in the calculations performed by the calculation unit 11, and the calculation results.

[0028] In Figure 1, the voltage value of the voltage input from the junction box 3 to the PCS 5 is measured by the PCS 5, and the power generation amount of the junction box 3 is calculated by the calculation unit 11 of the monitoring device 10. However, this is not limited to this method; the voltage value of the voltage input from the junction box 3 to the PCS 5 may be measured by the current measurement unit 4, and the power generation amount of the junction box 3 may be calculated by the current measurement unit 4, or the power generation amount may be measured by the current measurement unit 4. The power generation amount of the junction box 3 calculated or measured by the current measurement unit 4 is transmitted to the monitoring device 10.

[0029] Next, an example of the power generation amount for each junction box 3 used to detect abnormalities in the solar cell string 2 will be explained with reference to Figure 2.

[0030] Figure 2 is a characteristic diagram showing an example of the power generation amount for each junction box. The photovoltaic power generation system in Figure 2 is the same as the photovoltaic power generation system shown in Figure 1, but with eight solar cell strings 2 connected to one junction box 3, and three such junction boxes 3 are provided.

[0031] In Figure 2, the horizontal axis represents the passage of time, and the vertical axis represents the percentage of power generation. For the percentage of power generation, the maximum power generation from each junction box 3 is set to 100%, and the percentage represents the ratio of the power generation from the other junction boxes 3 to that maximum.

[0032] Figure 2 shows an example of the proportion of power generation in three junction boxes 3, which will be referred to as the first power generation P1, the second power generation P2, and the third power generation P3 below to distinguish them. In a photovoltaic power generation system, the amount of solar radiation fluctuates over time, and the current measurement unit 4 continuously measures the current output from the junction boxes 3. In Figure 2, the proportion of power generation is extracted and shown for the period from 13:00 to 15:00, which is a time of day when the amount of solar radiation is high and the fluctuations are small. Specifically, the first power generation P1 is 100%, the second power generation P2 is 88%, and the third power generation P3 is 64%. A threshold PS is set as a criterion for determining whether the amount of power generation has decreased, and in the example shown in Figure 2, it is set to 90%. In other words, if the proportion of power generation in the junction box 3 targeted for abnormality detection is below the threshold PS, it is determined that the amount of power generation has decreased. The threshold PS can be set based on the amount of power generated when one or more of the multiple solar cell strings 2 connected to the junction box 3 stop generating power. The threshold PS may be increased or decreased to provide a margin. In the example shown in Figure 2, eight solar cell strings 2 are connected to one junction box 3. When the maximum amount of power output from the junction box 3 is set to 100%, if the power generation of one of the solar cell strings 2 connected to the junction box 3 becomes 0, and the power generation of the other solar cell strings 2 is at its maximum, the percentage of power generation from the junction box 3 becomes 87.5%. Based on this percentage, and after taking a margin, the threshold PS is set to 90%. In this example, the threshold PS was calculated based on the case where the number of solar cell strings 2 with zero power generation is 1, but the number of solar cell strings 2 can also be set arbitrarily. By using the amount of power generated when one or more solar cell strings 2 stop generating power as a baseline, it is possible to detect an anomaly in which the junction box 3 contains solar cell strings 2 that are not generating power. When calculating the percentage of power generation, the average value may be calculated from the power generation amount at any given time period.

[0033] Next, the flow for detecting an anomaly in solar cell string 2 will be explained with reference to Figure 3.

[0034] Figure 3 is a flowchart showing the processing flow of an abnormality detection method for a photovoltaic power generation system according to the first embodiment of the present invention.

[0035] In step S01, the amount of power generated from the junction box 3 is calculated. The calculation unit 11 calculates the amount of power generated from the junction box 3 based on the current value measured by the current measurement unit 4 and the input voltage value measured by the PCS 5. In this embodiment, the calculation unit 11 calculates the amount of power generated from the junction box 3 from the current value based on the measurement results of the current measurement unit 4, but it is not limited to this, and the voltage value may be measured in the current measurement unit 4 and the amount of power generated calculated in the current measurement unit 4 may be transmitted to the monitoring device 10. Alternatively, in step S01, only the current value output from the junction box 3 may be measured, and in subsequent steps, the current value may be used instead of the amount of power generated for calculations.

[0036] In step S02, the calculation unit 11 extracts the maximum power generation amount. In other words, it identifies the maximum power generation amount (maximum power generation amount) from among the multiple power generation amounts calculated for each junction box 3 in step S01.

[0037] In step S03, the calculation unit 11 calculates the power generation reduction rate. That is, based on the difference between the maximum power generation amount extracted in step S02 and the power generation amount of the junction box 3 that is the target of abnormality detection, the calculation unit calculates the percentage of power generation reduction (power generation reduction rate).

[0038] In step S04, the calculation unit 11 calculates the number of abnormal strings and terminates the process. That is, the power generation reduction rate calculated in step S03 is compared with the power generation rate of one solar cell string 2 and converted into the number of abnormal strings. The process may also include multiplying the power generation reduction rate by the maximum power generation to calculate the total reduction in power generation. By recording the total reduction in power generation calculated here and accumulating it over the year, it is possible to estimate the expected increase in power generation if the factors causing the power generation reduction are improved.

[0039] The number of abnormal strings is calculated based on the number of solar cell strings 2 connected to one junction box 3 and the power generation reduction rate. The following explanation refers to an example shown in Figure 2. In the example shown in Figure 2, eight solar cell strings 2 are connected to one junction box 3, and the maximum power generation when all solar cell strings 2 are generating their maximum power is the first power generation P1. At the second power generation P2, the power generation reduction rate is 12%, and the number of abnormal strings is determined to be one. At the third power generation P3, the power generation reduction rate is 36%, and the number of abnormal strings is determined to be three.

[0040] In the example shown in Figure 3, the number of abnormal strings was calculated based on the power generation reduction rate, but it may also be calculated from the amount of power generation reduction. By comparing the magnitude of the reduced power generation with the power generation of one solar cell string 2, it is possible to convert it into the number of abnormal strings.

[0041] Furthermore, in the examples shown in Figures 2 and 3, the amount of power generated was calculated to detect abnormalities in the solar cell string 2. However, instead of calculating the amount of power generated, the current value measured at the junction box 3 may be used. In this case, the calculation unit 11 detects abnormalities in the solar cell string 2 by comparing the magnitude of the current at each junction box 3 based on the current value transmitted from the data conversion unit 8. By using the current value instead of the amount of power generated, abnormal strings can be detected and the number of abnormal strings can be calculated, similar to the examples shown in Figures 2 and 3.

[0042] The notification unit 12 notifies the user of the junction box 3 to which a solar cell string 2 with reduced power output is connected. By notifying the user of the junction box 3 to which a solar cell string 2 with reduced power output is connected in this way, the user can be made aware of the junction box 3 that requires maintenance. In addition, the notification to the user may also include the number of abnormal strings. This allows the user to be made aware of the number of abnormal strings that require maintenance. Furthermore, the notification to the user may be prioritized for the junction box 3 with the largest number of abnormal strings. This allows the user to be made aware of the junction box 3 that requires priority maintenance.

[0043] In the processing flow shown in Figure 3, steps S02 and S03 calculate the power generation reduction rate from the identified maximum power generation amount and use this to determine whether there is a solar cell string 2 with reduced power generation. However, the process is not limited to this, and as shown in the example in Figure 2, a threshold PS may be used to determine whether there is a solar cell string 2 with reduced power generation. In this case, instead of steps S02 and S03, a step of comparing a pre-set threshold PS with the power generation rate of the junction box 3 to be detected for abnormality may be performed. Alternatively, even in this case, a step (corresponding to step S04) may be performed to calculate the number of abnormal strings using the maximum power generation amount output from the junction box 3 as the maximum power generation amount.

[0044] In this way, by measuring the current value of the junction box 3, abnormalities in the solar cell string 2 can be detected, and costs can be reduced by eliminating the need for a measuring instrument to monitor the current value of the solar cell string 2 itself. Furthermore, by converting the power generation reduction rate, power generation amount, or current reduction amount into the number of abnormal strings, it is possible to detect if an abnormal string is included in the junction box. In addition, based on the values ​​related to the power generation reduction rate, power generation amount, and current reduction amount in the junction box 3, it is possible to detect whether there is a solar cell string 2 that is not generating power, and the number of solar cell strings that are not generating power. Therefore, it is possible to detect whether there is an abnormal string due to a blown fuse in the junction box 3, and the number of abnormal strings due to a blown fuse.

[0045] As described above, the calculation unit 11 sets the largest power generation amount among the multiple junction boxes 3 as the maximum power generation amount, compares the maximum power generation amount with the power generation amount of the target junction box 3, and calculates the percentage decrease in power generation. In this way, by calculating the percentage decrease in power generation based on the maximum power generation amount, the number of solar cell strings 2 whose power generation has decreased can be calculated with high accuracy.

[0046] In the configuration described above, a fuse corresponding to the solar cell string 2 is provided in the junction box 3. Therefore, by checking the junction box 3 during maintenance, it is possible to address any abnormalities in the solar cell string 2 caused by a blown fuse. In addition, the number of abnormal strings may be notified to the user. This allows the user to understand the amount of maintenance required.

[0047] (Second Embodiment) Next, an abnormality detection device 1 for a photovoltaic power generation system according to the second embodiment of the present invention will be described with reference to the drawings. Note that the abnormality detection device 1 for a photovoltaic power generation system according to the second embodiment is substantially the same as that of the first embodiment, so the description and drawings will be omitted.

[0048] Figure 4 is a flowchart showing the processing flow of an abnormality detection method for a photovoltaic power generation system according to the second embodiment of the present invention.

[0049] In step S11, the amount of power output from the junction box 3 is calculated, similar to step S01 in Figure 3.

[0050] In step S12, the calculation unit 11 corrects for individual differences. Individual differences can occur in the solar cell strings 2 and junction boxes 3 due to various factors. Factors that cause individual differences include, for example, the amount of sunlight in the environment in which they are installed and differences depending on the type of solar cell string 2. In this embodiment, such individual differences are eliminated by correction. To correct for individual differences, a coefficient corresponding to each junction box 3 can be set, taking into account the current value measured in advance. Alternatively, multiple coefficients may be set for each factor that causes individual differences in a single junction box 3. As described above, by correcting for individual differences, the amount of power generated for comparison can be calculated with greater accuracy.

[0051] In step S13, similar to step S02 in Figure 3, the calculation unit 11 extracts the maximum amount of power generated.

[0052] In step S14, the calculation unit 11 calculates the power generation reduction rate, similar to step S03 in Figure 3.

[0053] In step S15, the calculation unit 11 corrects the rate of decrease in power generation. That is, the calculation unit 11 corrects the rate of decrease in power generation based on fluctuations in power generation. By correcting the rate of decrease in power generation by considering fluctuations in power generation caused by various factors, the rate of decrease in power generation can be calculated with greater accuracy. The correction of the rate of decrease in power generation is not limited to just one item, but may also be based on correcting multiple items.

[0054] Specific adjustments include, for example, a lower limit for solar radiation and specific increases or decreases. In weather conditions where sufficient solar radiation is not obtained, such as rainy or cloudy days, power generation decreases, making it unsuitable for determining whether there is a problem with solar cell string 2. Therefore, a lower limit for solar radiation can be set, and when the amount falls below this predetermined limit, it can be determined that it is not a day to determine whether there is a problem with solar cell string 2, as the amount of solar radiation has not exceeded the lower limit. Furthermore, even if the amount of solar radiation exceeds the lower limit over the entire day, there are times of day, such as morning and evening or rainy days, that are not suitable for determining whether there is a problem with solar cell string 2. Therefore, in addition to the daily lower limit for solar radiation, a lower limit for solar radiation can be set for a predetermined period, such as an hourly, minutely, or secondly unit, and power generation during times when the amount of solar radiation falls below the set lower limit can be excluded from the calculation of the power generation reduction rate. In addition, power generation that has increased or decreased drastically compared to the amount of power generation in the preceding and succeeding times can be excluded from the calculation of the power generation reduction rate as a specific increase or decrease.

[0055] In step S16, the calculation unit 11 calculates the number of abnormal strings, similar to step S04 in Figure 3. The process may also include multiplying the power generation reduction rate by the maximum power generation to calculate the total power generation reduction.

[0056] In step S17, the calculation unit 11 analyzes the number of abnormal strings or the total decrease in power generation over time to calculate the decrease in power generation for each factor, and then terminates the process.

[0057] Specific factors contributing to a decrease in power generation include blown fuses, shading, and aging. Alternatively, decreases in power generation not related to these factors may be grouped together and classified as decreases due to other factors. When there is a sharp increase in the daily number of abnormal strings or decrease in power generation, the increase should be determined to be due to a blown fuse. Furthermore, decreases in the number of abnormal strings or power generation that change with the passage of time or season should be determined to be due to shading. Finally, decreases in the number of abnormal strings or power generation that fluctuate slightly from day to day should be determined to be due to aging.

[0058] Furthermore, the system may include a process for storing the calculated decrease in power generation for each factor in units of string count or units of electrical energy. If the decrease in power generation for each factor is stored in units of string count, it can be used to determine whether or not daily maintenance activities are necessary and to propose maintenance content. If the decrease in power generation for each factor is stored in units of electrical energy, the amount of increase in power generation after improving the factors causing the decrease can be estimated by accumulating these amounts over the year.

[0059] Furthermore, the embodiments disclosed herein are illustrative in all respects and do not constitute a basis for restrictive interpretation. Accordingly, the technical scope of the present invention is not to be interpreted solely by the embodiments described above, but is defined based on the claims. This also includes all modifications within the meaning and scope of equivalents to the claims. [Explanation of Symbols]

[0060] 1. Anomaly detection device 2 Solar cell strings 3. Connection Box 4 Current measurement section 5 PCS 6 Load equipment 7 Commercial power system 8. Data Conversion Unit 10 Monitoring equipment 11 Arithmetic section 12 Notification Department 13 Storage section

Claims

1. An anomaly detection device for a photovoltaic power generation system, which includes a junction box to which multiple solar cell strings are connected, A current measuring unit for measuring the current output from the aforementioned junction box, The system includes a calculation unit that, based on the measurement results of the current measuring unit, calculates a value relating to the decrease in power generation from the maximum power generation when the power generation of all the solar cell strings is at its maximum, and calculates the number of solar cell strings that are not generating power included in the junction box based on the calculated value relating to the decrease in power generation and the magnitude of the power generation of one of the solar cell strings. An anomaly detection device for solar power generation systems, characterized by the following features.

2. An anomaly detection device for a photovoltaic power generation system comprising multiple junction boxes to which multiple solar cell strings are connected, A current measuring unit that measures the current output from each of the multiple connection boxes, The system includes a calculation unit that, based on the measurement results of the current measuring unit, sets the largest of the multiple junction boxes as the maximum power generation amount, compares the maximum power generation amount with the power generation amounts of the other junction boxes to calculate a value relating to the decrease in power generation amount of the other junction boxes, and calculates the number of solar cell strings that are not generating power based on the calculated value relating to the decrease in power generation amount of the other junction boxes and the power generation amount of one solar cell string. An anomaly detection device for solar power generation systems, characterized by the following features.

3. An anomaly detection device for a photovoltaic power generation system comprising multiple junction boxes to which multiple solar cell strings are connected, A current measuring unit that measures the current output from each of the multiple connection boxes, The system includes a calculation unit that, based on the measurement results of the current measuring unit, sets the largest of the multiple junction boxes as the maximum power generation amount, compares the maximum power generation amount with the power generation amounts of the other junction boxes to calculate the percentage decrease in the power generation amount of the other junction boxes relative to the maximum power generation amount, and calculates the number of solar cell strings that are not generating power based on the calculated percentage decrease in the power generation amount of the other junction boxes and the power generation rate of one solar cell string. An anomaly detection device for solar power generation systems, characterized by the following features.

4. An abnormality detection device for a solar power generation system according to claim 2 or claim 3, The calculation unit, when comparing the power generation amounts of the multiple connection boxes, corrects for individual differences in each of the multiple connection boxes. An anomaly detection device for solar power generation systems, characterized by the following features.

5. An abnormality detection device for a solar power generation system according to any one of claims 1 to 4, The system includes a notification unit that notifies the junction box to which the solar cell string that is not generating power is connected. An anomaly detection device for solar power generation systems, characterized by the following features.

6. An abnormality detection device for a solar power generation system according to any one of claims 1 to 5, The junction box has a fuse corresponding to each of the multiple solar cell strings, The calculation unit detects that a string of solar cells that is not generating power is included, thereby detecting that a string of abnormal cells due to a blown fuse is included. An anomaly detection device for solar power generation systems, characterized by the following features.

7. A method for detecting anomalies in a photovoltaic power generation system comprising multiple solar cell strings and a junction box to which the multiple solar cell strings are connected, A current measurement step involves having the current measuring unit measure the current output from the junction box, The calculation unit includes a calculation step of calculating a value relating to the decrease in power generation from the maximum power generation when the power generation of all the multiple solar cell strings is at its maximum, based on the measurement results of the current measurement unit, and calculating the number of solar cell strings that are not generating power included in the junction box based on the calculated value relating to the decrease in power generation and the magnitude of the power generation of one of the solar cell strings. A method for detecting abnormalities in a solar power generation system, characterized by the following features.

8. A method for detecting anomalies in a photovoltaic power generation system comprising multiple solar cell strings and a junction box to which the multiple solar cell strings are connected, A current measurement step involves having the current measuring unit measure the current output from the junction box, The calculation unit includes a calculation step of setting the largest of the multiple junction boxes to the maximum power generation amount based on the measurement results of the current measurement unit, comparing the maximum power generation amount with the power generation amounts of the other junction boxes to calculate a value relating to the decrease in power generation amount of the other junction boxes, and calculating the number of solar cell strings that are not generating power based on the calculated value relating to the decrease in power generation amount of the other junction boxes and the power generation amount of one solar cell string. A method for detecting abnormalities in a solar power generation system, characterized by the following features.

9. A method for detecting anomalies in a photovoltaic power generation system comprising multiple solar cell strings and a junction box to which the multiple solar cell strings are connected, A current measurement step involves having the current measuring unit measure the current output from the junction box, The calculation unit includes a calculation step of setting the largest power generation amount among the multiple junction boxes as the maximum power generation amount based on the measurement results of the current measurement unit, comparing the maximum power generation amount with the power generation amounts of the other junction boxes to calculate the percentage decrease in the power generation amount of the other junction boxes relative to the maximum power generation amount, and calculating the number of solar cell strings that are not generating power based on the calculated percentage decrease in the power generation amount of the other junction boxes and the power generation rate of one solar cell string. A method for detecting abnormalities in a solar power generation system, characterized by the following features.

Images