Abnormality determination system and power generation system

Abstract

The present invention provides an abnormality determination system and a power generation system capable of quickly, compared to the prior art, determining an abnormality of solar power generation equipment.　The present invention comprises: a power generation amount measurement unit that measures the amount of power generated by solar power generation equipment; a data acquisition unit that acquires solar radiation amount data; a calculation unit that calculates a division value by dividing the integrated value of the daily power generation amount by the integrated value of the daily solar radiation amount; and a data accumulation unit that accumulates combinations of the power generation amount and the solar radiation amount, or the division values. The invention is configured to determine an abnormality in any case among (1)-(3) described below. (1) A case in which an average value of the division values for a reference period is calculated in advance from division values calculated in the past, and the gradient of the division values with respect to the average value of the division values for the reference period falls below a threshold value. (2) A case in which an average value of the division values for the reference period is calculated by the calculation unit, and the gradient of the division values with respect to the average value of the division values for the reference period falls below the threshold value. (3) A case in which the gradient of the regression line of the division values for a determination period falls below a threshold value.

Description

[Technical field]

[0001] The present invention relates to an abnormality determination system for determining an abnormality in a photovoltaic power generation facility and a power generation system including the abnormality determination system. [Background technology]

[0002] With the recent spread of solar power generation equipment, there have been rare cases of fires caused by malfunctions of solar power generation equipment. Solar power generation facilities for home use are often installed on the roofs of houses, and houses usually have fire alarms installed inside the houses. Conventional fire alarms have the problem of not being able to quickly detect fires in solar power generation facilities installed on the roofs of houses. Therefore, Patent Document 1 proposes a solar power generation system in which a fire alarm wire is provided on the solar panel, and when the temperature of the solar panel reaches a certain temperature or higher, a signal is sent from the fire alarm wire to a fire alarm device. In this way, the system detects abnormal heat generation and fires in the solar panel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-184355 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the photovoltaic power generation system of Patent Document 1, an abnormality cannot be detected until the solar cell panel generates abnormal heat or a fire occurs. Therefore, there is a problem that it takes at least one month from the occurrence of an abnormality in the solar cell panel to discovery, and usually takes several months.

[0005] Therefore, an object of the present invention is to provide an abnormality determination system and a power generation system that can determine an abnormality in a photovoltaic power generation facility earlier than conventional systems. [Means for solving the problem]

[0006] In view of the above problems, the inventors have closely examined past fire cases involving modules, connectors, etc., and have found a certain law between the amount of power generated per kW of system capacity per day and the amount of inclined surface solar radiation at that location. That is, when the changes in the amount of power generated per kW of system capacity per day (hereinafter also referred to as the division value) against the amount of inclined surface solar radiation per day were plotted, it was found that, as shown in the graph of Figure 8(a), although there were singular points and variations, the overall value gradually decreased from the point two months before the fire occurred, and a significant drop in the division value occurred as a precursor to the occurrence of a fire.

[0007] As a result of thorough research based on the above findings, one aspect of the present invention that was arrived at is an abnormality determination system that is connected to a solar power generation facility and determines an abnormality in the solar power generation facility, the abnormality determination system having a power generation amount measurement unit that measures the amount of power generated by the solar power generation facility, a data acquisition unit that acquires data on solar radiation, a calculation unit that calculates a divided value by dividing the integrated value of power generation per day measured by the power generation amount measurement unit by the integrated value of solar radiation per day acquired by the data acquisition unit, and a data storage unit that stores a combination of the measured data on power generation amount and solar radiation, or the divided value, and that determines an abnormality in any of the following cases (1) to (3). (1) The average of the division values ​​for a reference period is calculated in advance from the division values ​​calculated in the past, and the slope of the division value relative to the average of the division values ​​for the reference period falls below a threshold value. (2) The calculation unit calculates an average value of the division values ​​for a reference period, and the slope of the division value relative to the average value of the division values ​​for the reference period falls below a threshold value. (3) If the slope of the regression line of the divided values ​​of the judgment period falls below the threshold value.

[0008] The term "regression line" used here refers to a line that represents the central distribution tendency of a set of data, and is calculated using the least squares method.

[0009] According to this aspect, signs of abnormality can be detected by changes in the slope of the division value and abnormalities can be identified before abnormal heat generation or fire occurs, making it possible to identify abnormalities in photovoltaic power generation equipment earlier than in the past.

[0010] In a preferred aspect, when the slope of the divided value with respect to the average value of the divided values ​​for the reference period falls below the threshold value continuously or intermittently a number of times, it is determined that an abnormality has occurred.

[0011] According to this aspect, since the condition for determining an abnormality is that the slope falls below the threshold value multiple times, erroneous determination of an abnormality can be suppressed even if a singular point is present.

[0012] Here, the inventor further examined the graph in Figure 8(a) and concluded that by taking a one-week moving average for each division value and detecting changes in the slope of the division value, as in the graph in Figure 8(b), the variation in the division values ​​can be further alleviated and abnormalities can be detected more accurately.

[0013] A preferred aspect derived from this consideration is that the calculation unit calculates the average value of the divided values ​​for a judgment period, and judges that an abnormality has occurred if the slope of the average value of the divided values ​​for the judgment period relative to the average value of the divided values ​​for the reference period falls below a threshold value.

[0014] According to this aspect, since the moving average of the divided value during the determination period including the present is calculated, even if there is a singular point in the divided value during the determination period, it is smoothed out, and an abnormality can be determined more accurately.

[0015] In a preferred aspect, the solar radiation data includes inclined solar radiation.

[0016] According to this aspect, a more accurate determination can be made.

[0017] In a preferred aspect, the measured daily power generation amount is the power generation amount per kW of system capacity, and the absolute value of the threshold value is greater than the absolute value of the slope due to deterioration of the solar power generation equipment over time calculated in accordance with IEC 60904-3.

[0018] In a more preferred aspect, the absolute value of the threshold is 0.005 m. 2 / kW·day or more.

[0019] According to these aspects, erroneous determination of a failure can be further suppressed.

[0020] A preferred aspect is to have a notification means for notifying the occurrence of an abnormality when it is determined that an abnormality has occurred.

[0021] According to this aspect, since the occurrence of an abnormality is notified, the user or the like can easily notice the abnormality.

[0022] In a preferred aspect, the solar power generation facility has a solar power generation device and a power conditioner that converts the power generated by the solar power generation device into AC power of a predetermined frequency, and has an error detection unit that detects error information of the power conditioner and uses the error information to determine an abnormality.

[0023] According to this aspect, since the error information of the power conditioner is used to determine the abnormality, the abnormality can be determined more accurately.

[0024] A more preferred aspect is to classify the error information into first error information related to the amount of power generation and second error information not related to the amount of power generation, and to increase the threshold value on the condition that the error information is the first error information.

[0025] According to this aspect, the threshold for determining an abnormality is lowered on the condition that the error information in the power conditioner is first error information related to the amount of power generation, so that an abnormality can be determined more quickly.

[0026] A more preferred aspect is to have an arc information acquisition unit that acquires arc information related to arc discharges in the photovoltaic power generation device or between the photovoltaic power generation device and the power conditioner, and to determine an abnormality using the arc information.

[0027] According to this aspect, since the abnormality is determined using the arc information, the abnormality can be determined more quickly.

[0028] However, the actual power generation amount of a photovoltaic power generation device is usually affected by external factors such as the shadow of a building, etc. In other words, there is a discrepancy between the accumulated theoretical power generation amount per week predicted from the actual measured value of the amount of solar radiation obtained from the Japan Meteorological Agency, etc., and the accumulated actual power generation amount per week by the actual measurement. Even if the actual power generation amount is monitored, the actual power generation amount fluctuates greatly, and it is difficult to determine whether the fluctuation of the actual power generation amount is due to the amount of solar radiation or an abnormality. In addition, data on the amount of solar radiation and actual power generation are measured multiple times in a day, and the values ​​for the time periods during which they are measured vary from day to day. Therefore, the inventor compared the actual power generation amount in the same time period on each day of the week, and focused on the maximum power generation amount in each time period on each day of the week. That is, the theoretical power generation amount is the power generation amount when all external factors are eliminated, and the maximum power generation amount is the maximum power generation amount with extremely small influence of external factors, so it was thought that the theoretical power generation amount and the maximum power generation amount in each time period would be close to each other. Based on this idea, the inventor compared the accumulated actual power generation per week (ratio A) against the accumulated theoretical power generation per week with the accumulated actual power generation per day (ratio B) obtained by extracting the maximum actual power generation per day for each time period on each day of the week against the accumulated theoretical power generation for one day, which was obtained by extracting the maximum theoretical power generation per day for each time period on each day of the week.The inventor then discovered that, as shown in Figure 9, ratio B was closer to 100% than ratio A, and the variation from the theoretical value was reduced. Based on this discovery, the inventor considered that since the daily integrated value of the maximum actual power generation for each time period on each day of the week is generally close to the daily integrated value of the maximum theoretical power generation for each time period on each day of the week, by monitoring the daily integrated value of the maximum actual power generation for each time period, it is possible to reduce the impact of external factors and extract fluctuations due to abnormalities.

[0029] One aspect of the present invention derived from the above considerations is an abnormality determination system that is connected to a solar power generation facility and determines an abnormality in the solar power generation facility, the abnormality determination system having a power generation measurement unit that measures the amount of power generated by the solar power generation facility, a calculation unit that creates accumulated power generation data for one day within a specified period of time, and a data storage unit that stores a combination of the amount of power generated and the time of measurement measured by the power generation measurement unit, or the accumulated power generation data for one day, the accumulated power generation data for one day being created by dividing a day into time slots at specified times, extracting the maximum power generation for each time slot within the specified period of time, and accumulating the extracted maximum power generation amounts, and determining that an abnormality has occurred if the slope of the accumulated power generation data for one day falls below a threshold value.

[0030] According to this aspect, the maximum power generation per kW for each time period within a specified period is extracted, and an abnormality is determined using the change in the slope of the integrated power generation data for one day of the maximum power generation for each time period, thereby making it possible to determine an abnormality more accurately. According to this aspect, since an abnormality is judged based on the slope of the unit power generation amount data in the judgment period, it is possible to judge an abnormality even if a singular point is present.

[0031] One aspect of the present invention is an anomaly determination system that is connected to a photovoltaic power generation facility and determines an anomaly in the photovoltaic power generation facility, the anomaly determination system including: a power generation amount measurement unit that measures the amount of power generated by the photovoltaic power generation facility; a data acquisition unit that acquires data on an amount of solar radiation; a calculation unit that creates one-day integrated power generation amount data and one-day integrated solar radiation amount data within a predetermined period of time; and a data storage unit that stores a combination of the amount of power generated by the power generation amount measurement unit, the measured time, and the solar radiation amount data, or the one-day integrated power generation amount data and the one-day integrated solar radiation amount data, the one-day integrated power generation amount data being stored for each predetermined time period in one day. the one-day solar radiation data is created by dividing a day into time slots at predetermined hours, extracting the maximum solar radiation for each time slot within the specified period, and integrating the extracted maximum solar radiation amounts; the one-day comparative integrated power generation data is calculated using the one-day solar radiation data; and if the slope of the division value obtained by dividing the one-day integrated power generation data by the one-day comparative integrated power generation data falls below a threshold value, an abnormality is determined to have occurred.

[0032] According to this aspect, since there is no need to use weather conditions such as cloudy or rainy days for the judgment, errors can be further suppressed even if the solar radiation measurement point and the installation location of the power generation equipment are far apart.

[0033] One aspect of the present invention is a power generation system including the abnormality determination system and the photovoltaic power generation facility.

[0034] According to this aspect, abnormalities in photovoltaic power generation equipment can be detected more accurately and earlier than in the past. Effect of the Invention

[0035] According to the abnormality determination system and power generation system of the present invention, an abnormality in a photovoltaic power generation facility can be determined earlier than in the past. [Brief description of the drawings]

[0036] [Figure 1]1 is a configuration diagram that illustrates a power generation system according to a first embodiment of the present invention. [Diagram 2] 4 is a flowchart for determining an abnormality in the power generation system of FIG. 1. [Diagram 3] 11 is an explanatory diagram for extracting the maximum power generation amount in the power generation system of the third embodiment of the present invention, where (a) to (g) are histograms of the power generation amount for each day of the week, and (h) is a histogram in which the maximum power generation amount for each hour of the week is extracted. Hatching indicates the maximum power generation amount when comparing each day of the week. [Figure 4] 13 is a flowchart for setting a base point in a power generation system according to a fourth embodiment of the present invention. [Diagram 5] 13 is an explanatory diagram for extracting the maximum amount of solar radiation in the power generation system according to the fifth embodiment of the present invention, where (a) to (g) are histograms of the amount of solar radiation for each day of the week, and (h) is a histogram in which the maximum amount of solar radiation is extracted for each hour of the week. Hatching indicates the maximum amount of solar radiation when comparing each day of the week. [Figure 6] FIG. 11 is a schematic diagram showing a power generation system according to another embodiment of the present invention. [Figure 7] 10 is a flowchart for determining an abnormality in a power generation system according to another embodiment of the present invention. [Figure 8] Graphs used by the inventor for his consideration: (a) is a graph of the division value against the date, and (b) is a graph of the one-week moving average of the division value against the date. [Figure 9] 1 is a graph used by the inventor for his consideration, showing the ratio of the actually measured power generation amount to the theoretical power generation amount for each date. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] Hereinafter, embodiments of the present invention will be described in detail. In the following, the term "average" refers to the arithmetic mean unless otherwise specified.

[0038] As shown in FIG. 1, the power generation system 1 of the first embodiment of the present invention is composed of a solar power generation equipment 2 and an abnormality judgment device 3 (abnormality judgment system), and is capable of one-way or mutual communication with external organizations 101, 102, a communication terminal 103, and a management company 104 via a network 100 such as an intranet or the Internet.

[0039] As shown in FIG. 1, the solar power generation facility 2 includes, as main components, a solar power generation device 10, a power conditioner 11 (hereinafter, also simply referred to as PWB 11), and connection wiring 12. The solar power generation device 10 is equipped with a photoelectric conversion device that converts light energy into electrical energy, and more specifically, it is equipped with a solar cell that extracts DC power from sunlight. The power conditioner 11 is a power conversion device that converts DC power or AC power into AC power of a predetermined frequency. The connection wiring 12 is a wiring that connects the photovoltaic power generation device 10 and the inverter 11, and is an output wiring that outputs DC power from the photovoltaic power generation device 10 side to the inverter 11 side.

[0040] The abnormality judgment device 3 comprises a central processing unit consisting of an arithmetic unit that performs calculations on data and a control unit that controls each device, a memory device that stores programs and data, an input device that inputs data from the outside, and an output device that outputs data to the outside. As shown in FIG. 1, the abnormality judgment device 3 has, as its main components, a calculation unit 20, a data accumulation unit 21, an abnormality judgment unit 22, a solar radiation data acquisition unit 23, an arc information acquisition unit 24, a power generation measurement unit 25, an error detection unit 26, an alarm means 27, and a communication unit 28.

[0041] The calculation unit 20 is a part that performs calculations such as the calculation of division values, which will be described later, in accordance with various programs. The data storage unit 21 is a part that stores data such as the amount of power generation, information related to the amount of power generation, time, etc. The data storage unit 21 of this embodiment can store a combination of the amount of power generation per 1 kW of system capacity measured by the power generation amount measurement unit 25 and the amount of solar radiation acquired by the solar radiation amount data acquisition unit 23, or data of the divided value. The abnormality determination unit 22 is a part that compares the divided value with a threshold value and determines whether an abnormality occurs. The solar radiation amount data acquisition unit 23 is a part that acquires solar radiation amount data from an external organization 101 via a communication unit 28 and a network 100 . The arc information acquisition unit 24 is connected to the connection wiring 12 that connects the photovoltaic power generation device 10 and the inverter 11, and is a component that constantly acquires information about arc discharge in the photovoltaic power generation device 10. The arc information acquisition unit 24 is capable of detecting DC arc discharge caused by a broken cable or poor contact in a connector, based on the waveform of the current passing through the connection wiring 12 that is connected to the DC power side of the inverter 11, etc.

[0042] The power generation amount measuring unit 25 is a component that constantly monitors and measures the amount of power generated by the photovoltaic power generation device 10 via the power conditioner 11. The error detection unit 26 is a component that constantly monitors the inverter 11 for the presence or absence of error information. The notification means 27 is a notification device that notifies a user, the management company 104, or the like, when the abnormality determination unit 22 determines that an abnormality has occurred. The notification method of the notification means 27 is not particularly limited, and can be, for example, by sound, color, image, language, or the like. The notification means 27 of this embodiment is capable of sending a notification from the communication unit 28 via the network 100 to the user's communication terminal 103, the management company 104, etc. The communication unit 28 is capable of communicating with external organizations 101 and 102, a communication terminal 103, a management company 104, and the like via a network 100.

[0043] The external organizations 101 and 102 are organizations that publish information on the amount of solar radiation, such as the amount of global solar radiation, in each region. The communication terminal 103 is a terminal capable of one-way communication or mutual communication via the network 100. The communication terminal 103 may be, for example, a fixed terminal such as a computer, or a portable terminal such as a mobile phone, a smartphone, or a tablet.

[0044] Next, a recommended operation of the abnormality determination unit 22 for determining an abnormality (hereinafter, also referred to as an abnormality determination operation) in the power generation system 1 of this embodiment will be described with reference to the flowchart of FIG.

[0045] First, the counter i is set to 0 (step S1), and the timer is reset to the initial state (step S2).Then, the timer is turned on (step S3), and the power generation amount measurement unit 25 constantly measures the power generation amount, and calculates the power generation amount data per kW of system capacity per day from the integrated value of the power generation amount per day.The solar radiation amount data acquisition unit 23 also acquires data on the amount of solar radiation per day in the installation area from the external organization 101 on the same day. Then, at least a combination of the following data (1) and (2) or the following data (3) is stored in the data storage unit 21. (1) Daily power generation data (2) Power generation data per 1kW of system capacity per day (3) The value obtained by dividing the data on the amount of solar radiation per day and the data on the amount of power generation per 1 kW of system capacity per day by the amount of solar radiation (hereinafter, simply referred to as the divided value) Specifically, the divided value is calculated by the following formula (1).

[0046]

number

[0047] Here, the inclined surface solar radiation can be calculated by the following formula (2).

[0048]

number

[0049] The total solar radiation refers to the amount of solar radiation from the sun reaching a horizontal surface on the ground from all over the sky, and values ​​published by an external meteorological organization 101 such as the Japan Meteorological Agency can be used. The correction coefficient can be calculated by correcting the angle in the installation area based on the data published by external organizations such as the New Energy and Industrial Technology Development Organization (NEDO) on a daily basis (for example, NEDO's database of annual monthly solar radiation (MONSOLA-11) (URL: http: / / app0.infoc.nedo.go.jp / metpv / monsola.html)). Specifically, the correction coefficient can be calculated by dividing the amount of solar radiation taking into account the azimuth angle and tilt angle in the installation area by the amount of global solar radiation.

[0050] Moreover, while the error detection unit 26 determines whether or not error information is being output from the inverter 11 (step S4), the presence or absence of an arc discharge is detected based on the arc information acquired by the arc information acquisition unit 24 (step S5).

[0051] Here, the error information is information that an error has occurred in the inverter 11, and the error information in this embodiment includes first error information related to the amount of power generation, such as an abnormal current value, and second error information unrelated to the amount of power generation, such as an abnormal command. In other words, the first error information is information that is one-to-one related to a malfunction that may lead to a fire or the like, and the second error information is information that is not one-to-one related to a malfunction that may lead to a fire or the like. The arc information is information related to an arc discharge and has a one-to-one correspondence with the arc discharge.

[0052] When the determination period T1 has elapsed (Yes in step S6) with no error information or arc discharge occurring after the timer is turned on, the calculation unit 20 calculates a division value from the amount of power generation and the amount of solar radiation on that day. The calculation unit 20 also uses the average value of the division values ​​in the past reference period T2 to calculate the slope of the division value in the determination period T1 relative to the average value of the division values ​​in the past reference period T2.

[0053] Here, the judgment period T1 is preferably from one day to two weeks, and more preferably from one day to five days. The reference period T2 is preferably 20 days or more and 2 years or less, and more preferably 1 month or more and 1 year or less. In this embodiment, the judgment period T1 is one day, and the reference period T2 is the most recent month including the time when the judgment period T1 has elapsed. In other words, the reference period T2 in this embodiment is set to a period of at least twice the judgment period T1.

[0054] If the slope of the divided value at the end of the judgment period T1 relative to the average value of the divided value for the reference period T2 is less than the threshold value (Yes in step S7) and the counter i exceeds n (Yes in step S8), it is judged to be an abnormality (step S9), and the notification means 27 notifies the user's communication terminal 103, the management company 104, etc. (step S10).

[0055] In this case, the threshold value is preferably a negative value, and the absolute value of the threshold value is greater than the absolute value of the slope due to aging degradation of the photovoltaic power generation facility 2 calculated in accordance with IEC 60904-3. In other words, the absolute value of the threshold value is preferably greater than the nominal output degradation rate under standard international test conditions (STC). The absolute value of the threshold value is preferably at least twice the slope of the long-term reliability described in the specifications of the solar power generation device 10, and is preferably 0.005 m 2 A value of 0.1 kW·day or higher is preferable. Furthermore, n is a natural number of 2 or more, preferably 3 or more and 7 or less, and more preferably 4 or more and 6 or less.

[0056] On the other hand, if the slope of the divided value after the judgment period T1 has elapsed relative to the average value of the divided values ​​for the reference period T2 is equal to or greater than the threshold value, i.e., if it is within the threshold range (No in step S7), the process returns to step S2, the timer is reset, and the same operation is performed. Furthermore, if the slope of the divided value at the end of the judgment period T1 relative to the average value of the divided value in the reference period T2 is less than the threshold value, i.e., exceeds the threshold range (Yes in step S7), and counter i is equal to or less than n (No in step S8), counter i is set to i+1 (step S11), the process returns to step S2, the timer is reset, and the same operation is performed.

[0057] If error information has been output to the inverter 11 in step S4 (No in step S4), the error information is classified into first error information, which is information that is one-to-one related to the amount of power generation, and second error information, which is information that is not one-to-one related to the amount of power generation, and it is determined whether the information is the first error information (step S12).

[0058] If the error information is the first error information (Yes in step S12), the on / off status of the flag is checked (step S13), and if the flag is off (Yes in step S13), the threshold is changed (step S14), the flag is turned on (step S15), and the process returns to step S5. When changing the threshold in step S14, it is preferable to change the threshold to ⅓ or more and ⅔ or less of the currently set threshold. In this range, it is possible to detect an abnormality early while suppressing erroneous determination of the abnormality. In this embodiment, when changing the threshold in step S14, the threshold is changed to ½ of the currently set threshold.

[0059] On the other hand, if the error information in step S12 is the second error information and not the first error information (No in step S12), or if the flag is on in step S13 (No in step S12), the threshold is not changed and the process returns to step S5.

[0060] Moreover, if an arc discharge is detected in step S5 (No in step S5), the process proceeds to step S9 without determining the inclination, and determines that an abnormality has occurred (step S9).

[0061] According to the power generation system 1 of this embodiment, signs of abnormality can be detected by changes in the slope of the division value, and the abnormality can be determined before abnormal heat generation or fire occurs, so that an abnormality in the solar power generation equipment 2 can be determined earlier than a fire or the like occurs in the solar power generation equipment 2.

[0062] According to the power generation system 1 of the present embodiment, when the abnormality determination unit 22 determines an abnormality, a notification is sent to the management company 104, so that a facility manager at the management company 104 can promptly head to the site to investigate. That is, according to the power generation system 1 of the present embodiment, an on-site investigation is prompted, and workers can check for any damage or the like, thereby preventing a major disaster such as a fire from occurring.

[0063] According to the power generation system 1 of the present embodiment, an abnormality is determined to occur when the divided value falls below the threshold value continuously or intermittently multiple times. This makes it possible to prevent erroneous determinations and more accurately determine an abnormality.

[0064] Next, a power generation system according to a second embodiment of the present invention will be described. Note that the same components as those in the power generation system 1 according to the first embodiment will be denoted by the same reference numerals and will not be described below.

[0065] The power generation system of the second embodiment differs from the power generation system 1 of the first embodiment in the determination of an abnormality by the abnormality determination unit 22. Specifically, in the first embodiment, in step S7 of Fig. 2, the slope of the divided value at the end of the judgment period T1 relative to the average value of the divided values ​​in the reference period T2 is compared with a threshold value. On the other hand, in the power generation system of the second embodiment, in step S7, the slope of the average value of the divided values ​​in the judgment period T1 relative to the average value of the divided values ​​in the reference period T2 is compared with a threshold value. That is, in the power generation system of the second embodiment, the slope of the moving average of the divided values ​​at the end of the judgment period T1 is compared with a threshold value. That is, the p-term moving average is calculated, and the slope of the p-term moving average including the divided value when the determination period T1 has elapsed is compared with the threshold value. The type of moving average is not particularly limited, but a simple moving average is preferable. It is preferable that the period of the partition is shorter than the judgment period T1, and the number of partitions p is 3 or more and 10 or less.

[0066] According to the power generation system of the second embodiment, even if there is a singular point in the divided value within the determination period T1, the singular point is smoothed out, so that an abnormality can be determined more accurately.

[0067] Next, a power generation system according to a third embodiment of the present invention will be described.

[0068] The power generation system of the third embodiment differs from the power generation system 1 of the first embodiment in the determination of an abnormality by the abnormality determination unit 22. In the power generation system of the third embodiment, the power generation amount measuring unit 25 constantly monitors the amount of power generation, and the calculation unit 20 creates one-day integrated power generation amount data for each predetermined period T4. Specifically, the power generation system of the third embodiment divides a day into time slots every predetermined time T3, compares the amount of power generation per kW in each time slot during the predetermined period T4 using the calculation unit 20, and extracts the maximum amount of power generation per kW in each time slot. The extracted maximum amounts of power generation are then integrated to calculate the integrated amount of power generation for one day, and this is accumulated in the data accumulation unit 21 as data on the integrated amount of power generation for one day per the predetermined period T4.

[0069] In this case, it is preferable that the predetermined time T3 is a time that can be equally divided into 24 hours. The predetermined time T3 is preferably more than 0 hours and less than 24 hours, and more preferably 0.5 hours or more and 3 hours or less. In this embodiment, the predetermined time T3 is two hours, as shown in Fig. 3. Note that the measurement of the amount of power generated by the power generation amount measuring unit 25 may exclude the time of sunset. The predetermined period T4 is a period of 2 days or more, preferably 3 days or more and 2 weeks or less, and more preferably 4 days or more and 10 days or less. The predetermined period T4 in this embodiment is 1 week.

[0070] That is, in this embodiment, as shown in Figures 3(a) to 3(g), a day is divided into two-hour time slots, the amount of power generation for each time slot on each day of the week is calculated, and the amount of power generation for each time slot on each day of the week is compared to extract the maximum amount of power generation for each time slot (see hatching in Figures 3(a) to 3(g)). Then, as shown in Figure 3(h), the maximum amount of power generation for each extracted time slot is added up to calculate the integrated amount of power generation for one day, and this is stored in the data storage unit 21 as integrated power generation data for one day per week.

[0071] Then, in step S7 of FIG. 2, if the slope of the current daily integrated power generation data relative to the average value of the daily integrated power generation data in the judgment period T1 including the present falls below a threshold value (Yes in step S7) and counter i exceeds n (Yes in step S8), it is determined that an abnormality has occurred (step S9).

[0072] At this time, the determination period T1 in this embodiment is a period longer than the predetermined period T4, and is preferably a period twice or more longer than the predetermined period T4. Moreover, it is preferable that the lapse of the determination period T1 coincides with the lapse of the predetermined period T4.

[0073] According to the power generation system of the third embodiment, the maximum power generation amount per 1 kW in each time period within a predetermined period T4 is extracted, the integrated value of the extracted maximum power generation amount in each time period is regarded as the integrated power generation amount data for one day, and an abnormality is judged based on the slope of the integrated power generation amount data for one day in the judgment period T1. Therefore, the abnormality judgment unit 22 can judge an abnormality without using the solar radiation amount data.

[0074] Next, a power generation system according to a fourth embodiment will be described.

[0075] In the power generation system of the fourth embodiment, the base point of the gradient of the divided value is set not to the average value of the divided values ​​in the past reference period T2 but to a divided value that satisfies a certain condition.

[0076] Specifically, the power generation amount data per day is calculated, and the base point is judged each time the divided value is calculated. As shown in the flowchart of Fig. 4, first, a counter j is set to 0 (step S31), and when the divided value is calculated (step S32), it is judged whether the divided value is less than the average value for the past reference period T2 (step S33).

[0077] If the divided value is less than the average value for the past reference period T2 (Yes in step S33), the process proceeds to step S34, where it is determined whether the counter j exceeds m. If the counter j exceeds m (Yes in step S34), the current division value is set as the base point (step S35). In this case, m is a natural number of 2 or more, preferably 3 or more and 7 or less, and more preferably 4 or more and 6 or less.

[0078] On the other hand, if the divided value is equal to or greater than the average value for the past reference period T2 (No in step S33), the counter j is reset (step S36) and the process proceeds to step S32. If the counter j is equal to or smaller than m in step S34 (No in step S34), the counter j is incremented by j+1 (step S37), and the process proceeds to step S32.

[0079] Then, when the base point is set, the power generation system of this embodiment proceeds to step S1 in FIG. 2, and in step S7, compares the gradient with respect to the base point with a threshold value.

[0080] According to the power generation system of the fourth embodiment, since the actual division value is used as the base point of the gradient, it is possible to detect an abnormality more accurately.

[0081] Next, a power generation system according to a fifth embodiment of the present invention will be described.

[0082] In the power generation system of the fifth embodiment, similarly to the power generation system of the third embodiment, the power generation amount is constantly measured by the power generation amount measuring unit 25, and the amount of solar radiation is constantly acquired at predetermined time intervals or at predetermined time intervals by the solar radiation amount data acquiring unit 23. In the power generation system of the fifth embodiment, the calculation unit 20 creates one-day integrated power generation amount data and one-day integrated solar radiation amount data within a predetermined period T4. Specifically, the power generation system of the fifth embodiment, like the power generation system of the third embodiment, divides a day into time periods every predetermined time T3, compares the amount of power generation per kW in each time period in the predetermined period T4 by the calculation unit 20, and extracts the maximum amount of power generation per kW in each time period.Then, the extracted maximum amounts of power generation are integrated to calculate the integrated amount of power generation for one day, and this is accumulated in the data accumulation unit 21 as data on the integrated amount of power generation for one day per the predetermined period T4. 5, the power generation system of the fifth embodiment divides one day into time slots at predetermined times T3, compares the amount of solar radiation in each time slot in a predetermined period T4 by the calculation unit 20, and extracts the maximum amount of solar radiation for each time slot.Then, the extracted maximum amounts of solar radiation are integrated to calculate the integrated amount of solar radiation for one day, and this is accumulated in the data accumulation unit 21 as data on the integrated amount of solar radiation for one day per predetermined period T4. Furthermore, the power generation system of the fifth embodiment calculates a comparative integrated power generation amount from the integrated solar radiation amount for one day, and accumulates this in the data accumulation unit 21 as comparative integrated power generation amount data. The comparative cumulative power generation amount is calculated using the following formula (3).

[0083]

number

[0084] The loss coefficient is the loss that occurs when the solar power generation device 10 generates power, and can be calculated by multiplying it by the temperature correction coefficient stipulated in the display guidelines established by the Japan Photovoltaic Energy Association (JPEA), the conversion efficiency of the power conditioner 11, and other loss coefficients (for convenience, the above method will be referred to as the JPEA method hereinafter).

[0085] Then, in step S7 of FIG. 2, if the slope of the divided value obtained by dividing the integrated power generation data for one day in the judgment period T1 including the present by the comparative power generation data for one day in the judgment period T1 falls below the threshold value (Yes in step S7) and the counter i exceeds n (Yes in step S8), it is determined that an abnormality has occurred (step S9).

[0086] According to the power generation system of the fifth embodiment, the judgment can be made without using weather conditions such as cloudy days or rainy days, so that the error that occurs when the measurement point of the amount of solar radiation and the installation location of the solar power generation equipment 2 are separated can be further suppressed.

[0087] In the above-described embodiment, the calculation unit 20 and the like are provided in the abnormality determination device 3, but the present invention is not limited to this. The calculation unit 20 and the like may be provided in an external server 200 connected via a network 100 and used for calculations and the like. In this case, the power generation system according to the present invention also includes the network 100 and the external server 200. 6 includes an arc information acquisition unit 24, a power generation amount measurement unit 25, an error detection unit 26, a notification means 27, and a communication unit 28 in the abnormality determination device 3, and includes a calculation unit 20, a data storage unit 21, an abnormality determination unit 22, a solar radiation amount data acquisition unit 23, and a communication unit 201 in the external server 200. In this case, the communication unit 28 of the abnormality determination device 3 and the communication unit 201 of the external server 200 can communicate with each other via the network 100.

[0088] In the above embodiment, when an arc discharge is detected by the arc information acquisition unit 24 in step S5 of Fig. 2, the process proceeds to step S9, and the abnormality determination unit 22 determines that an abnormality has occurred, but the present invention is not limited to this. As shown in Fig. 7, an abnormality may be determined based on the degree of deviation from the average of the integrated value for each short period of time. Specifically, as shown in the flowchart of Fig. 7, when an arc discharge is detected in step S5 (No in step S5), the timer is reset to its initial state (step S40), and then the timer is turned on (step S41). When the judgment period T5 has elapsed since the timer was turned on (Yes in step S42) and the deviation of the divided value at the end of the judgment period T5 from the average divided value in the reference period T2 exceeds the second threshold value (Yes in step S43), the process proceeds to step S9 and an abnormality is determined to have occurred. Here, the judgment period T5 is a period shorter than the judgment period T1 and is a period equal to or longer than the interval between measurements of the amount of power generated by the power generation amount measuring unit 25. The judgment period T5 is preferably equal to or longer than 2 hours and equal to or shorter than 3 days. The second threshold value is preferably a value between −100% and −10%. Moreover, the deviation is expressed by the following formula (4).

[0089]

number

[0090] In the above embodiment, the slope is calculated based on the rate of change of the divided value at the end of the judgment period T1 relative to the average value of the divided values ​​in the past reference period T2, but the present invention is not limited to this. The slope may be calculated based on a regression line during the judgment period T1. That is, the slope may be calculated by calculating the divided value at every predetermined time during the judgment period T1 and calculating a regression line for the calculated divided value.

[0091] In the embodiment described above, the solar radiation amount data acquisition unit 23 acquires solar radiation amount data from the external organization 101 via the network 100, but the present invention is not limited to this. A solar radiation amount measuring means such as a solar radiation meter may be connected to directly measure the amount of solar radiation at the installation location and use the measured amount of solar radiation as data on the amount of solar radiation.

[0092] In the above embodiment, the amount of power generation per kW of system capacity per day, which is calculated by normalizing the integrated value of the amount of power generation per day by the system capacity, is used to calculate the slope, but the present invention is not limited to this. The integrated value of the amount of power generation per day may be used to calculate the slope without normalizing it.

[0093] In the above embodiment, after the judgment period T1 has elapsed, the calculation unit 20 calculates the average value of the division values ​​in the past reference period T2 and calculates the slope of the division value during the judgment period T1 relative to the average value of the division values ​​in the past reference period T2, but the present invention is not limited to this. The average value of the division values ​​in the reference period T2 may be calculated by the calculation unit 20 or another device before the judgment period T1 has elapsed. In other words, the average value of the division values ​​in the reference period T2 may be a value calculated in advance before the abnormality judgment unit 22 executes the abnormality judgment operation, independently of the abnormality judgment operation.

[0094] In the above embodiment, the power generation amount measuring unit 25 constantly measures the amount of power generation, but the present invention is not limited to this. The power generation amount measuring unit 25 may constantly measure the amount of power generation periodically.

[0095] In the above embodiment, the abnormality determination device 3 is directly connected to the network 100, but the present invention is not limited to this. The abnormality determination device 3 may be indirectly connected to the network 100 via a wireless base station that can be connected to the network 100.

[0096] In the fifth embodiment described above, the comparative integrated power generation amount for one day is calculated based on the JPEA method, but the present invention is not limited to this. The comparative integrated power generation amount for one day may be calculated by other methods. For example, the comparative integrated power generation amount for one day may be calculated according to JIS C 8907:2005.

[0097] In the above-described embodiments, each component may be freely substituted or added between the respective embodiments as long as it falls within the technical scope of the present invention. [Explanation of symbols]

[0098] 1. Power generation system 2. Solar power generation facilities 3. Anomaly Judgment Device (Anomalous Judgment System) 10. Solar power generation equipment 11 Power conditioner 12 Connection Wiring 20 Calculation section 21 Data Storage Section 22 Abnormality determination section 23 Solar radiation data acquisition section 24 Arc information acquisition unit 25 Power generation measurement section 26 Error detection section 27 Notification methods 101,102 External organizations

Claims

1. An abnormality determination system that is connected to a photovoltaic power generation facility and determines an abnormality in the photovoltaic power generation facility, A power generation amount measuring unit that measures the amount of power generated by the solar power generation facility; A data acquisition unit for acquiring data on the amount of solar radiation; a calculation unit that calculates a divided value by dividing an integrated value of the amount of power generation per day measured by the power generation amount measurement unit by an integrated value of the amount of solar radiation per day acquired by the data acquisition unit; a data storage unit that stores a combination of the measured power generation amount and the solar radiation amount or the divided value; An abnormality determination system that determines that an abnormality has occurred in any of the following cases (1) to (4). (1) The average value of the division values ​​for a reference period is calculated in advance from the division values ​​calculated before the judgment period has elapsed, and the ratio of the division value at the end of the judgment period to the average value of the division values ​​for the reference period or the ratio of the average value of the division values ​​for the judgment period falls below a threshold value. (2) The calculation unit calculates the average value of the divided values ​​for a reference period, and the ratio of the divided value at the end of a judgment period to the average value of the divided values ​​for the reference period or the ratio of the average value of the divided values ​​for the judgment period falls below a threshold value. (3) The slope of the regression line of the multiple divided values ​​during the judgment period falls below a threshold value. (4) Before the judgment period has elapsed, there is a division value that is less than the average value of the division values ​​in the reference period and the division value is set as a base point, and the ratio of the current division value to the division value set as the base point falls below a threshold value.

2. The anomaly determination system according to claim 1 , wherein an anomaly is determined to exist when a ratio of the divided value to an average value of the divided values ​​in the reference period falls below a threshold value continuously or intermittently a number of times.

3. The abnormality determination system according to claim 1 , wherein the data on the amount of solar radiation includes an amount of solar radiation on an inclined surface.

4. The measured amount of power generation per day is the amount of power generation per kW of system capacity, The abnormality determination system according to any one of claims 1 to 3, wherein the absolute value of the threshold value is greater than an absolute value of a slope due to aging of the photovoltaic power generation facility calculated in accordance with IEC 60904-3.

5. The absolute value of the threshold is 0.005 m ２ The anomaly determination system according to claim 4, wherein the value is equal to or greater than 1000 W / kW-day.

6. The abnormality determination system according to any one of claims 1 to 5, further comprising a notification means for notifying the occurrence of an abnormality when an abnormality is determined.

7. The solar power generation facility includes a solar power generation device and a power conditioner that converts the power generated by the solar power generation device into AC power of a predetermined frequency, An error detection unit that detects error information of the power conditioner, The abnormality determination system according to any one of claims 1 to 6, wherein the error information is used to determine an abnormality.

8. 8. The abnormality determination system according to claim 7, wherein the error information is classified into first error information related to the amount of power generation and second error information not related to the amount of power generation, and the threshold value is increased on the condition that the error information is the first error information.

9. An arc information acquisition unit that acquires arc information related to the arc discharge between the solar power generation device or the solar power generation device and the power conditioner, The abnormality determination system according to claim 7 or 8, wherein the arc information is used to determine an abnormality.

10. An abnormality determination system that is connected to a photovoltaic power generation facility and determines an abnormality in the photovoltaic power generation facility, A power generation amount measuring unit that measures the amount of power generated by the solar power generation facility; A calculation unit that creates integrated power generation data for one day within a predetermined period; a data storage unit that stores a combination of the amount of power generation measured by the power generation amount measurement unit and the measurement time, or the integrated power generation amount data for one day; The one-day integrated power generation data is created by dividing a day into time periods each having a predetermined time, extracting a maximum amount of power generation in each time period within the predetermined time period, and integrating the extracted maximum amounts of power generation, The abnormality determination system determines that an abnormality has occurred when a ratio of current integrated power generation amount data for one day to an average value of the integrated power generation amount data for one day during a determination period falls below a threshold value.

11. An abnormality determination system that is connected to a photovoltaic power generation facility and determines an abnormality in the photovoltaic power generation facility, A power generation amount measuring unit that measures the amount of power generated by the solar power generation facility; A data acquisition unit for acquiring data on the amount of solar radiation; A calculation unit that creates one-day integrated power generation data and one-day integrated solar radiation data within a predetermined period; a data storage unit that stores a combination of data on the amount of power generation measured by the power generation amount measurement unit, the measured time, and the amount of solar radiation, or the one-day integrated power generation amount data and the one-day integrated solar radiation amount data; The one-day integrated power generation data is created by dividing a day into time periods each having a predetermined time, extracting a maximum amount of power generation in each time period within the predetermined time period, and integrating the extracted maximum amounts of power generation, The solar radiation amount data for one day is created by dividing one day into time periods each having a predetermined time, extracting the maximum solar radiation amount for each time period within the predetermined time period, and integrating the extracted maximum solar radiation amounts, A one-day comparative integrated power generation amount data is calculated using the one-day solar radiation amount data, and when a slope of a divided value obtained by dividing the one-day integrated power generation amount data by the one-day comparative integrated power generation amount data falls below a threshold value, it is determined that an abnormality has occurred; An anomaly determination system, wherein the slope of the divided value is a ratio of change of the current divided value to an average value of the divided value over a determination period.

12. A power generation system comprising the abnormality determination system according to any one of claims 1 to 11 and the solar power generation facility.

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