JP2015099858A - Abnormality detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an abnormality determination device for determining the abnormality of a solar panel, the cost increase of which is suppressed.SOLUTION: An abnormality determination device for determining the abnormality of a solar panel 100 including a plurality of strings 90 each consisting of a series connection of a plurality of solar cell modules 80 includes a current detector 11 for detecting the string current, i.e., the output current of the string 90, of each string 90, a deviation arithmetic unit 13 for calculating the average value of the string current detected from the plurality of strings 90, and calculating the deviation from the average value of each string current, and a determination unit 14 for determining an abnormal string 90 out of the plurality of strings 90, based on the deviation of respective string currents calculated by the deviation arithmetic unit 13.

Description

  The present invention relates to an abnormality determination device that determines abnormality of a solar panel including a plurality of strings in which a plurality of solar cell modules are connected in series.

  In recent years, construction of photovoltaic power plants has been promoted against the background of energy problems. At a solar power plant, power is generated using solar panels. The solar panel is configured by connecting solar cells in series and parallel to form a solar cell module, and further connecting in parallel a string in which the solar cell modules are connected in series. For example, in a large-scale solar power plant called mega solar, hundreds of thousands of solar cell modules are installed on a vast land. Since the power generation amount of such a solar panel depends on the solar radiation amount and the environmental temperature, it is difficult to say that the power generation amount is always constant. For this reason, when the power generation amount decreases, it is not easy to specify whether the power generation amount has decreased due to the effects of solar radiation and environmental temperature, or whether the power generation amount has decreased due to a failure of the solar cell module.

  Therefore, it is conceivable to measure the solar radiation amount and the environmental temperature in all the solar cell modules and strings, and determine whether or not the solar cell module has failed using the measurement results. However, when such a method is adopted, the number of solar radiation meters and thermometers becomes enormous, which increases the cost of the solar panel. In view of such a problem, a technique for identifying an abnormality of a solar panel has been studied (for example, Patent Document 1).

  The abnormality detection system in the solar power generation device described in Patent Document 1 includes the first power generation amount of the solar power generation system when each of the plurality of solar power generation devices constituting the solar power generation system is sequentially stopped. The second power generation amount of the solar power generation system when all of the plurality of solar power generation devices are operating is measured, and the difference between the second power generation amount and the first power generation amount is obtained. This difference is used to detect which of the plurality of solar power generation devices is abnormal.

JP 2012-190947 A

  In the technique described in Patent Document 1, it is necessary to sequentially stop each photovoltaic power generation device in order to measure the first power generation amount, and it is necessary to provide a switch for each photovoltaic power generation device. For this reason, it becomes a factor of the cost increase of a photovoltaic power generation system.

  In view of the above problems, an object of the present invention is to provide an abnormality determination device that determines an abnormality of a solar panel while suppressing an increase in cost.

  In order to achieve the above object, the characteristic configuration of the abnormality determination device according to the present invention is characterized in that an output current of the string is determined in order to determine abnormality of a solar panel provided with a plurality of strings in which a plurality of solar cell modules are connected in series. A current detection unit that detects the string current for each string, and a deviation calculation unit that calculates an average value of the string currents detected from the plurality of strings and calculates a deviation from the average value for each string current And a determination unit that determines an abnormal string among a plurality of strings based on the deviation of each string current calculated by the deviation calculation unit.

  In general, the output of the solar panel changes according to the amount of sunlight irradiated to the solar panel and the temperature of the solar panel even when all the strings constituting the solar cell module are not abnormal. For this reason, with the above-described characteristic configuration, an average value of string currents of a plurality of strings constituting the solar panel is obtained, and each string is abnormal based on a deviation of each string current based on the average value. Since it can be determined whether or not there is a string, it is possible to appropriately determine whether or not the string is abnormal depending on the driving situation. As described above, according to the present configuration, the reference for determining whether or not the string is abnormal is determined according to the driving situation without being set in advance as a constant value. It is possible to accurately determine whether or not the changing solar panel string is abnormal. Therefore, erroneous determination can be prevented, and an abnormality determination device that determines abnormality of the solar panel can be realized.

It is the figure which showed typically the structure of the abnormality determination apparatus.

  The abnormality determination device according to the present invention is configured to have a function of determining abnormality of a solar panel without significant cost increase. Hereinafter, the abnormality determination device 1 of the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of the abnormality determination device 1 according to this embodiment.

  The abnormality determination device 1 determines an abnormality of the solar panel 100 including a plurality of strings 90 in which a plurality of solar cell modules 80 are connected in series. As shown in FIG. 1, the solar panel 100 includes a plurality of strings 90 configured by connecting solar cells 70 in series and parallel to form a solar cell module 80 and connecting the solar cell modules 80 in series. Configured. Each output of the string 90 is input to the connection box 200, and the output of the connection box 200 is input to the current collection box 300.

  The abnormality determination device 1 that detects an abnormality of the solar panel 100 includes each function unit of a current detection unit 11, a storage unit 12, a deviation calculation unit 13, a determination unit 14, and an explicit unit 15. In the present embodiment, the current detection unit 11, the storage unit 12, the deviation calculation unit 13, and the determination unit 14 are provided in the connection box 200 described above. Each functional unit described above has a CPU as a core member, and the above-described functional units for performing various processes for determining an abnormality of the solar panel 100 are constructed by hardware and / or software.

  The current detection unit 11 detects a string current that is an output current of the string 90 for each string 90. The string 90 is an aggregate of solar cells 70 as described above. From such a solar battery cell 70, a direct current voltage and a direct current corresponding to the irradiation amount of light applied to the solar battery cell 70 and the temperature of the place where the solar battery cell 70 is installed are output. The current detection unit 11 detects the direct current from the solar battery cell 70 for each string 90. For this reason, the current detection unit 11 is configured as a direct current ammeter and is arranged for each string 90 constituting the solar panel 100. The detection result by the current detection unit 11 is transmitted to the storage unit 12 described later. The detection result by the current detection unit 11 is “a current value of the string current”, which will be described as a “string current” below.

  The storage unit 12 sequentially stores the results detected by the current detection unit 11. The detected result is a direct current for each string 90. Sequential storage means storing every time a preset time elapses. The preset time may be 1 second, 1 hour, or 1 day. Of course, it may be one day or more and can be set as appropriate. When the storage unit 12 stores the result detected by the current detection unit 11, the storage unit 12 associates string information indicating the string 90 in which the result is detected and date / time information indicating the date and time when the result is detected with the result. And remember.

  The deviation calculation unit 13 calculates an average value of the string currents detected from the plurality of strings 90, and calculates a deviation with respect to the average value for each string current. The string current detected from the plurality of strings 90 corresponds to the string current stored in the storage unit 12 described above. The average value of the string current is a value obtained by adding the string current flowing in each string 90 constituting the solar panel 100 detected by the current detection unit 11 in the same time zone, and dividing it by the number of strings 90. . For this reason, the average value calculated by the deviation calculating unit 13 according to the present embodiment is not the average value of the string current flowing in one string 90.

  The deviation from the average value is the difference between the above average value and the string current used for calculating the average value. This deviation is calculated for each string current used in calculating the average value. Therefore, the deviation calculation unit 13 calculates an average value over a plurality of strings 90 using the string current of the string 90 detected in the same time zone stored in the storage unit 12, and calculates the average value and each of the average values. The deviation of the string 90 from the string current is calculated. The deviation obtained by the deviation calculation unit 13 is stored in the storage unit 12 together with time information indicating when the deviation is.

  The determination unit 14 determines an abnormal string 90 among the plurality of strings 90 based on the deviation of each string current calculated by the deviation calculation unit 13. The deviations of the respective string currents calculated by the deviation calculation unit 13 are stored in the storage unit 12. The determination unit 14 determines that the string 90 associated with a deviation larger than a preset ratio with respect to the average value of the string current among the deviations stored in the storage unit 12 is abnormal. Specifically, for example, when the deviation is less than 5% of the average value, the string 90 is not abnormal, and when the deviation is 5% or more of the average value of the string current, the string 90 is abnormal. Is preferable. Of course, the above “5%” is an example, and other values can be set. The determination result by the determination unit 14 is transmitted to the explicit unit 15.

  The specifying unit 15 specifies the string 90 that has been determined by the determining unit 14 that the string current is abnormal. Such clarification may be displayed on a monitor (not shown) provided in the abnormality determination apparatus 1 or, for example, a report is made to the contractor or management company that installed the solar panel 100 using an electric communication line. It may be explicit.

  In addition, the abnormality determination apparatus 1 mentioned above may be provided in the solar power plant provided with the solar panel 100, and may be provided in the management facility etc. in the place away from the solar power plant. In such a case, various detection results and determination results in the abnormality determination of the solar panel 100 can be transmitted and received via the electronic communication line.

  Conventionally, the solar cell module 80 generates heat due to, for example, a manufacturing defect such as a poor soldering of the solar cell module 80 or a hot spot phenomenon caused by the fallen leaves or bird excrement attached to the solar panel 100, and sunlight. Cases of fire from panel 100 have been reported. According to the abnormality determination device 1, since the abnormality of the string 90 can be appropriately determined as described above, such a fire based on the ignition from the solar panel 100 can be prevented in advance.

[Other Embodiments]
In the above embodiment, the determination unit 14 has been described as determining that the string 90 having a deviation larger than a preset ratio with respect to the average value of the string current is abnormal. However, the determination unit 14 may be configured to make a determination according to the amount of change in deviation over a predetermined period. That is, the determination unit 14 obtains a deviation for each preset time and stores the deviation in the storage unit 12 in time series, and the negative gradient of the deviation time series change stored in the storage unit 12 increases. It is also possible to determine that the string 90 is abnormal. In such a configuration, since the string current of the abnormal string 90 gradually decreases, it is easy to find such a change, and it is easy to determine whether or not the string current is abnormal.

In the said embodiment, the deviation calculating part 13 demonstrated calculating an average value using the string current detected in the same time slot | zone, and calculating a deviation based on this average value. However,
The deviation calculation unit can be configured to calculate the deviation except for a string current detected by the current detection unit 11 that is 20% or less of the rated output of the solar cell module 80 defined in advance. It is. The rated output of the solar cell module 80 is the output of the solar cell module 80 under a predetermined condition, and is described in, for example, the specifications of the solar cell module 80. The deviation calculation unit 13 calculates an average value using a string current obtained by excluding a value less than 20% of the rated output of the solar cell module 80 from the string current stored in the storage unit 12, so that the string 90 is abnormal. Even if there is, the average value of the string current can be obtained using the output from the normal string 90. Therefore, it is possible to improve the accuracy of determination as to whether or not the string 90 is abnormal.

  The abnormality determination device 1 according to the above embodiment can be configured without the solar radiation meter and the thermometer. For example, when the solar radiation meter and the thermometer are provided, the solar radiation amount and the solar panel 100 By estimating the power generation amount of the solar cell module 80 from the temperature and causing the deviation calculation unit 13 to calculate a deviation as an estimated average, for example, a lot defect over the entire solar cell module 80, dirt attached to the solar cell module 80, etc. It is possible to cope with the case where the output of the entire solar cell module 80 is reduced due to the above. In addition, since such solar radiation amount and environmental temperature are used only for estimating the electric power generation amount of the solar cell module 80, the solar radiation meter and the thermometer do not need to be provided in all the solar cell modules 80, and a plurality of solar cells Since it is only necessary to provide the battery module 80 in any one of the solar cell modules 80 serving as a reference, a significant cost increase can be suppressed. Further, even when a plurality of solar panels 100 are provided, the solar radiation meter and the thermometer do not have to be provided in all the solar panels 100, and any one solar panel 100 serving as a reference or any one serving as a reference. It is only necessary to provide one solar cell module 80.

  In the above embodiment, the abnormality determination device 1 has been described as detecting whether or not the string 90 is abnormal by detecting the string current of the string 90 constituting the solar panel 100. For example, when a very large number of solar panels 100 are used, such as a high-voltage interconnection with an installation capacity of 50 kW or more and less than 2 MW, or a solar power plant of a special high-voltage interconnection section with an installation capacity of 2 MW or more, 1, the output of each solar panel 100 is once collected in one of the plurality of connection boxes 200, and the output of the plurality of connection boxes 200 is further collected in one current collection box 300. . In this case, a deviation between the average value of the outputs of the plurality of connection boxes 200 and the output of the connection box 200 may be calculated, and it may be configured to determine whether or not the connection box 200 is abnormal based on this deviation. Is possible. Then, it is preferable to determine whether only the string 90 of the solar panel 100 connected to the connection box 200 determined to be abnormal is abnormal as described above. Thereby, even when the number of the solar panels 100 is very large, the number of processes related to determination can be reduced, so that the calculation load can be reduced.

  INDUSTRIAL APPLICABILITY The present invention can be used for an abnormality determination device that determines abnormality of a solar panel provided with a plurality of strings in which a plurality of solar cell modules are connected in series.

1: Abnormality determination device 11: Current detection unit 12: Storage unit 13: Deviation calculation unit 14: Determination unit 15: Clarification unit 80: Solar cell module 90: String 100: Solar panel

Claims (1)

An abnormality determination device for determining abnormality of a solar panel provided with a plurality of strings in which a plurality of solar cell modules are connected in series,
A current detection unit that detects a string current that is an output current of the string for each of the strings;
A deviation calculator that calculates an average value of the string currents detected from the plurality of strings and calculates a deviation from the average value for each string current;
A determination unit that determines an abnormal string among a plurality of strings based on a deviation of each string current calculated by the deviation calculation unit;
An abnormality determination device comprising:

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