Method for diagnosing solar cell modules, method for providing data services for diagnostic results, and diagnostic device.

Abstract

This invention provides a solar cell module diagnostic method and diagnostic apparatus that enables the estimation of the IV characteristics of numerous other solar cell modules at a site using a reference module whose IV characteristics according to specifications were obtained at a location that satisfies STC (Standard Measurement Conditions). [Solution] When the reference module is returned to its original location at the solar power plant, the field IV characteristics of the reference module returned to its original location are measured, and conversion coefficients M and N, which are the difference between the field IV characteristics and the reference IV characteristics, are determined. Using the conversion coefficients, the estimated reference IV characteristics of the other solar cell modules are determined from the field IV characteristics of the other solar cell modules.

Description

Technical Field

[0001] Embodiments of the present invention relate to a method for diagnosing a solar cell module, a data service method for diagnosis results, and a diagnostic apparatus.

Background Art

[0002] In a solar power plant, a solar cell array facing a certain obliquely upward direction is installed on a pedestal. In the solar cell array, a plurality of solar cell modules are arranged in a plane and connected in series. Further, one solar cell module is configured in a state where a plurality of cells are arranged in a plane and connected in series.

[0003] Generally, the most widely used solar cell modules have an output of 250 W to 450 W and a size of about 1600 mm × 1000 mm.

[0004] Before being shipped from the factory of the manufacturer, the solar cell module is subjected to quality evaluation. The quality evaluation includes five items: evaluation of power generation characteristics (hereinafter referred to as IV characteristics), evaluation of EL performance, visual inspection, withstand voltage performance evaluation, and insulation performance evaluation, and these are carried out by precise measurement.

[0005] Among these items, in particular, the IV characteristic evaluation is used to calculate the output power (W) of a solar power plant (a group of solar cell modules). This evaluation is an important factor for determining whether a solar cell module is handled as a product, for example, or as a reused product, for example.

[0006] By the way, the above-mentioned solar power plant is installed outdoors. The output power of a solar cell module used outdoors changes due to deterioration of components, scratches, etc. Therefore, when an abnormality occurs in the output power of the power plant, or when considering an appropriate method for reusing resources (reuse and recycling) due to the decommissioning of the power plant, diagnosis in units of solar cell modules is desired.

[0007] This diagnosis is generally carried out by the power generation company operating the solar power plant or the O&M (operation and maintenance) company, which conducts periodic inspections to check for damage or malfunctions visually and using simple inspection equipment. However, it is difficult to confirm the current specifications (actual values) of solar modules outdoors because the amount of power generated changes depending on the external temperature and amount of sunlight. In order to understand the current specifications (actual values) of solar modules, it is necessary to take measurements under STC (Standard Test Condition) set up indoors. STC is a standard measurement condition that sets a unified measurement environment for solar modules, and the specifications (actual values) obtained under this measurement environment are indicated on the solar modules. Solar power generation equipment refers to these specifications to calculate the output power of the entire solar power plant and to adjust the output power.

[0008] The STC (Surface Test Course) has three standard measurement conditions (environments) A to C, and the IV characteristics are measured using a device called a solar simulator that can reproduce these conditions. This solar simulator is usually located indoors in a test facility set up on a large site, like a factory. Standard measurement conditions: A) Temperature of the solar cell module being measured: within 25℃ ± 1℃ B) Irradiance of the light source used to generate power for the solar cell module during measurement: 1000 W / m 2 C) Light source wavelength for generating power in the solar cell module during measurement: AM1.5 Solar cell modules are placed indoors and their IV characteristics are measured in a temperature environment that satisfies the three conditions mentioned above, an environment with reference light (equivalent to solar radiation), and an environment with a predetermined spectral pattern of light. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2007-311487 [Patent Document 2] International Publication No. 2015 / 118608 [Overview of the project] [Problems that the invention aims to solve]

[0010] As described above, the current specifications (actual performance) of the solar modules installed in solar power plants are not known, and the degree of degradation of the solar array is estimated based on simple inspections conducted periodically and the monthly and yearly power generation (electricity sold) of the solar power plants.

[0011] Solar cell modules are used in large numbers at solar power plants. For example, a single solar power plant uses tens of thousands to tens of thousands of solar cell modules. Transporting all of these solar cell modules to a designated indoor location away from the solar power plant, measuring their IV characteristics under an STC environment, and then transporting the measured modules back to the solar power plant for reinstallation is difficult due to the enormous amount of effort and time required.

[0012] To reduce this effort and time, there is an outdoor IV characteristic measuring device that can be used at the site where the solar power plant is installed. This outdoor IV characteristic measuring device is connected to a thermometer and a pyranometer. The outdoor IV characteristic measuring device can correct the on-site IV characteristic measurement results taken outdoors based on temperature and solar radiation, and this correction aims to obtain IV characteristic data similar to that measured under an STC environment.

[0013] However, in the power generation environment of solar cell modules at solar power plants, there are changes in solar radiation (due to sunny, cloudy (changes in cloud conditions), rain, etc.) that cause power generation fluctuations of several hundred watts every few seconds. In addition, when looking at the entire solar cell module, there is a non-uniform temperature distribution (the outer edges are cooler, and the area around the junction box (J-BOX) tends to be hotter).

[0014] In other words, the amount of electricity generated by solar modules in operational (outdoor) environments is constantly fluctuating. Therefore, it is difficult to obtain stable (accurate) power generation conditions (power generation conditions close to those in an STC environment) to obtain the true IV characteristics outdoors. As a result, it is extremely difficult to estimate the IV characteristics under an STC environment (characteristics measured by STC) from outdoor IV characteristic measurements.

[0015] Therefore, the objective of this embodiment is to provide a method for diagnosing solar cells, a data service method for diagnostic results, and a diagnostic apparatus that enable the estimation of the IV characteristics of many other solar cells at a given site by removing one or more solar cell modules from a solar power plant, transporting them to a location that satisfies the STC (Standard Measurement Conditions), measuring the IV characteristics of the sample solar cell modules to obtain their specifications, bringing them back to the solar power plant, and using the sample solar cell modules as reference modules. [Means for solving the problem]

[0016] In one embodiment, one or more solar cell modules are transported from a solar power plant to a measurement location that satisfies the STC (Standard Measurement Conditions), and a reference IV characteristic is measured at the measurement location. The solar cell module from which this reference IV characteristic data is obtained is then used as the reference module. The reference module is returned to its original location at the solar power plant, and its field IV characteristics are measured. Then, coefficients M and N (hereinafter referred to as conversion coefficients), which are the difference between the field IV characteristics and the reference IV characteristics, are determined. Here, a method for diagnosing solar modules is provided, in which the reference IV characteristics of other solar modules are determined from the field IV characteristics of other solar modules at the original location, using the conversion coefficients. [Brief explanation of the drawing]

[0017] [Figure 1]FIG. 1 is an explanatory diagram showing a state in which a solar cell module is detached from an outdoor solar power plant and carried into an indoor measurement station in an indoor STC environment for characteristic measurement. [Figure 2] FIG. 2 is an explanatory diagram showing an example of the specifications of a solar cell module (reference module) measured at the measurement station of FIG. 1. [Figure 3] FIG. 3 is an explanatory diagram showing a state in which the reference module of FIG. 2 is returned to its original position in the original solar power plant. [Figure 4] FIG. 4 is a diagram showing an example of the temperature distribution when the solar cell module is operating in the power plant. [Figure 5] FIG. 12 is a diagram showing an example of a state where the characteristics of each of the reference module and other solar cell modules in the solar power plant are being measured. [Figure 6] FIG. 15 is a diagram showing an example of the specifications of a solar cell module obtained in an STC environment and an example of the IV characteristics of a solar cell module having this specification. [Figure 7] FIG. 18 is a diagram showing a comparison of the reference IV characteristics of the reference module in an STC environment and the measurement results of the on-site IV characteristics in a solar power plant, and a diagram explaining a processing method for obtaining information (conversion coefficient) on the difference between the reference IV characteristics and the on-site IV characteristics. [Figure 8] FIG. 21 is an explanatory diagram explaining a method of obtaining an estimated value of the reference IV characteristics of other solar cell modules in an STC environment by applying the conversion coefficient explained in FIG. 18 to the measured IV characteristics of other solar cell modules in a solar power plant. [Figure 9] FIG. 24 is a diagram showing a configuration example of a diagnostic device for diagnosing and adjusting a solar cell module. [Figure 10] FIG. 27 is a flowchart showing an operation example of a diagnostic device for diagnosing and adjusting a solar cell module. [Figure 11] FIG. 30 is a diagram showing a configuration example of an embodiment of a diagnostic device for a solar cell module. [Figure 12] FIG. 33 is a diagram showing an embodiment showing an example of utilization of various data acquired by the diagnostic device. [Modes for carrying out the invention]

[0018] The embodiments will be described below with reference to the drawings. The response of a solar cell module to changes in temperature and solar radiation depends on the components of the solar cell module (number of power generation cells, internal resistance, diodes, etc.) and the semiconductor characteristics of the power generation cells. In this embodiment, it is assumed that in a "single solar power plant" using solar cell modules from the same manufacturer and model, the output characteristics response to temperature and solar radiation is the same across tens to tens of thousands of solar cell modules.

[0019] Figure 1 shows the process of removing a solar cell module 103 from an outdoor solar power plant 100, transporting it to an indoor measurement station 200 in an STC environment, and measuring its characteristics. In reality, tens to tens of thousands of solar cell modules are used at the solar power plant 100, but for the sake of clarity, only three solar cell modules 101, 102, and 103 are shown here.

[0020] In this example, one solar cell module 103 is shown being brought to the measurement station 200, but multiple solar cell modules may also be brought in (sampled) as reference modules for measurement. The reason for this is that if the reference module of the sample exhibits, for example, a unique degradation compared to other solar cell modules in the solar power plant 100, there is a concern that this may result in a large error in the specification estimation results, which will be explained later. For this reason, when selecting a reference module, it is desirable to extract multiple sample modules, perform measurements at the STC, and then select the solar cell module with the least degradation as the reference module. In other words, it is desirable to select a module that can obtain specifications equal to or very close to the specifications at the time of shipment as a product.

[0021] The reference module 103, brought to the measurement station 200 in the STC environment, is measured by the measuring instrument 210, for example, its IV characteristics.

[0022] Figure 2 shows the measurement items, their units, and an example of the results after the above-mentioned reference module 103 has been measured. It also shows a graph of the IV characteristics.

[0023] The IV characteristic graph shows that the short-circuit current is 9.0[A] and the open-circuit voltage is 38.0[V]. It also shows that the optimal voltage is 31.0[V].

[0024] Figure 3 shows the reference module 103 being brought back to the solar power plant 100 and installed in its original location and orientation (installed in its original position on the mounting frame). Because the solar power plant 100 is outdoors, it is affected by natural sunlight. As a result, the reference module 103 is installed under the same conditions (solar radiation, temperature (distribution), etc.) as the other solar cell modules.

[0025] Figure 4 shows the temperature distribution typically observed when the solar cell module 105 is operating normally. When viewed from above, the upper region 1051 where the current collector box (J-BOX) is installed is hotter than other regions. In addition, the outer regions 1052 and 1053 of the solar cell module 105 tend to be hotter than other regions.

[0026] Therefore, as shown in Figure 3, after the reference module 103 is installed in its original location, it is desirable to connect it to the other solar cell modules that were originally installed and allow it to generate power for several hours until the temperature conditions of the other solar cell modules and the reference module 103 are unified.

[0027] Figure 5 shows the measurement of the IV characteristics of a reference module 103 and other solar cell modules 101 and 102 (hereinafter, the other solar cell modules will be referred to as other measurement modules) installed at the solar power plant 100, under actual sunlight conditions.

[0028] The measurement procedure may involve continuously measuring the reference module 103 and the other measurement modules 101 and 102 outdoors using a single IV characteristic measuring instrument. Alternatively, as shown in the figure, the reference module 103 and the other measurement modules 101 and 102 may be measured continuously or simultaneously using multiple IV characteristic measuring instruments 213, 211, and 212 outdoors.

[0029] Figure 6 shows an example of specifications obtained based on STC and an example of the IV characteristics of a solar cell module having these specifications. The specifications include, as shown in the upper part of the figure, maximum output Pm, nominal short-circuit current: Isc, nominal open-circuit voltage: Voc, nominal maximum output voltage: Vpm, nominal maximum output current: Ipm, nominal short-circuit current temperature coefficient: αIsc, and nominal open-circuit voltage temperature coefficient: βVoc. Furthermore, as shown in the lower part of the figure, the solar radiation per square meter is 1000 W / m². 2 ,800W / m 2 ,600W / m 2 ,400W / m 2 ,200W / m 2 This shows the IV characteristics in the case of ,. These IV characteristics show the change in power generation capacity under STC conditions and when the amount of solar radiation changes, assuming a standard light of 1000W / m² under clear skies. 2 (Same as the STC environment), or 200 W / m² assuming a decrease in solar radiation due to cloudy skies or rain. 2 This shows the IV characteristics up to [a certain point].

[0030] Figure 7 shows graph 701, which compares the IV characteristics (which may be called the reference IV characteristics) St of the aforementioned reference module 103 when measured in an STC environment (measurement station 200 in Figure 1) with the IV characteristics (which may be called the field IV characteristics) Lo when measured in an outdoor field environment (solar power plant 100 in Figure 5).

[0031] In Graph 701, if the ratio of current to voltage between the reference IV characteristic St and the field IV characteristic Lo is known, the ratio of IV characteristics between the STC environment and the field environment (which may also be called the stretching ratio) can be determined. To determine this ratio, in this embodiment, the reference IV characteristic St of the reference module is measured in the STC environment, and then the reference module is taken back to the field, where the field IV characteristic Lo of this reference module is measured.

[0032] Then, the ratio between the reference IV characteristic St and the field IV characteristic Lo is determined.

[0033] In this embodiment, the ratio of the reference IV characteristic St obtained using the above-mentioned reference module to the field IV characteristic Lo is prepared as a conversion coefficient (coefficient M, coefficient N). Then, coefficient M is used as the coefficient for current value conversion, and coefficient N is used as the coefficient for voltage value conversion. The idea is that by converting the field IV characteristics of other measurement modules using coefficients M and N, the reference IV characteristics of those other measurement modules can be estimated.

[0034] Graphs 702 and 703 in Figure 7 show an example of the procedure for determining the conversion coefficients (coefficient M, coefficient N) for the above-mentioned reference module. In graphs 701, 702, and 703 in Figure 7, the direction of the voltage value is set as the X axis and the direction of the current value is set as the Y axis.

[0035] First, we will explain an example of a method for obtaining a coefficient M to approximate the current value of the field IV characteristic Lo to the current value of the reference IV characteristic St.

[0036] As shown in Graph 702, the open-circuit voltage of the field IV characteristic Lo is matched (or normalized) to the open-circuit voltage Vst of the reference IV characteristic St of the reference module. The short-circuit current of the field IV characteristic Lo remains unchanged. As a result, the field IV characteristic Lo changes as shown in IV characteristic Lo1 in Graph 702.

[0037] In other words, the voltage values ​​(field voltage values) at each plotted position of the field IV characteristic Lo (Graph 701) change overall in the X-axis direction toward an increasing direction (it could also be said that it is normalized with respect to voltage only). To put it another way, the voltage values ​​at each other plotted position of the field IV characteristic Lo change in a similar ratio to the ratio by which the open-circuit voltage value of the field IV characteristic Lo changes to the open-circuit voltage value of the reference IV characteristic St (they change to the right in the figure).

[0038] On the other hand, the current level does not change much at this time (it could be said that it is not normalized). Therefore, since the current is not normalized, the IV characteristic Lo1 is indicated as the IV characteristic Lo1 for current adjustment.

[0039] In this state, the current difference between the reference IV characteristic St and the current adjustment IV characteristic Lo1 is then determined as a coefficient M at each voltage plot position (each plot position in the X-axis direction) (Graph 702).

[0040] Next, by adding the coefficient M to the current value of the field IV characteristic Lo1 at each plotted voltage position (each plotted position in the X-axis direction), the current value of the reference IV characteristic (value in the Y-axis direction) at each plotted position in the X-axis direction can be obtained. This means that the coefficient M has been obtained to approximate the current value of the field IV characteristic Lo with respect to the reference IV characteristic St.

[0041] Next, we will explain the principle for obtaining the coefficient N used to approximate the voltage value of the field IV characteristic Lo to the voltage value of the reference IV characteristic St.

[0042] As shown in Graph 703, the short-circuit current value of the field IV characteristic Lo is matched (or normalized) to the short-circuit current Ist (value in the Y-axis direction) of the reference IV characteristic St of the reference module. The open-circuit voltage value of the field IV characteristic Lo (value in the X-axis direction) remains unchanged. As a result, the field IV characteristic Lo changes as shown in IV characteristic Lo2 in Graph 703.

[0043] In other words, the current values ​​(field current values) at each plotted position of the field IV characteristic Lo (Graph 701) change overall in the Y-axis direction toward an increasing direction (it could also be said that it is normalized with respect to current only). To put it another way, the current values ​​at each other plotted position of the field IV characteristic Lo change in a similar ratio to the ratio by which the short-circuit current value of the field IV characteristic Lo changes to the short-circuit current value of the reference IV characteristic St (these change in the upward direction in the figure).

[0044] On the other hand, the voltage level does not change much at this time (it could be said that it is not normalized). Therefore, since the voltage is not normalized, the IV characteristic Lo1 is shown as the voltage-regulating IV characteristic Lo2.

[0045] In this state, the voltage difference between the reference IV characteristic St and the voltage adjustment IV characteristic Lo2 is then determined as a coefficient N at each plot position of the current (each plot position in the Y-axis direction) (Graph 703).

[0046] Next, by adding the coefficient N to the voltage value of the field IV characteristic Lo1 at each plotted position of the current (each plotted position in the Y-axis direction), the voltage value of the reference IV characteristic (value in the X-axis direction) at each plotted position in the Y-direction can be obtained. This means that the coefficient N has been obtained to approximate the voltage value of the field IV characteristic Lo with respect to the reference IV characteristic St.

[0047] The acquisition of the coefficients M and N described above involves measuring the field IV characteristic Lo of the reference module against the reference IV characteristic St of the reference module under the STC environment, and then determining the coefficients (M, N) (hereinafter referred to as conversion coefficients) that convert this field IV characteristic Lo to the reference IV characteristic.

[0048] Therefore, if the above coefficients (M, N), i.e., the conversion coefficients, are known, then conversely, if the field IV characteristic Lo is known, it is possible to estimate its reference IV characteristic St. However, this assumes that the product specifications of the reference module and the measurement module are the same or very similar at the time of shipment.

[0049] Taking advantage of this, the adjustment method for the solar cell module in this embodiment calculates (estimates) the reference IV characteristics of each of the other measurement modules 101 and 102 from the field IV characteristics of the other measurement modules 101 and 102 shown in Figure 5.

[0050] Figure 8 shows a method for estimating the reference IV characteristic Est (hereinafter referred to as the estimated reference IV characteristic Est) of the measurement module 101 shown in Figure 5. Graph 801 shows the field IV characteristic Lo11 of the measurement module 101, illustrating the stage before obtaining the estimated reference IV characteristic Est (shown by the dotted line) of the measurement module 101.

[0051] Earlier, we determined a conversion coefficient (M, N) that can convert the field IV characteristics of reference module 103 to the reference IV characteristics. This conversion coefficient (M, N) can be used as a coefficient to convert the field IV characteristics of measurement modules 101 and 102 to their respective reference IV characteristics.

[0052] Furthermore, various calculation methods are possible for obtaining estimated reference IV characteristics from on-site IV characteristics, such as linear approximation, polynomial approximation, and moving average approximation. In polynomial approximation using functions, the accuracy of the approximation improves as the degree increases.

[0053] Figure 9 shows the relationship between the solar power plant 100 and the diagnostic device (which may also be called a controller or electronic device) 900. The diagnostic device 900 has an interface 901, which can be connected to the interface 120 of the solar power plant 100. The connection method between the interfaces may be wired or wireless.

[0054] The diagnostic device 900 includes a system control unit 950. This system control unit 950 is connected via a bus line 930 to the interface 901, memory 902, operation unit 903, monitor control unit 904, conversion coefficient generator 921, IV characteristic estimator 922, etc. The monitor control unit 904 is connected to the monitor 905. The system control unit 950 controls each block within the diagnostic device 900.

[0055] The conversion coefficient generator 921 has a generation function for obtaining conversion coefficients (M,N), as explained in Figure 7. The IV characteristic estimator 922 has an estimation function for obtaining the estimated reference IV characteristics of other measurement modules, as explained in Figure 8.

[0056] The memory 902 described above includes a section for storing an identification ID set for the solar power plant, the number of solar modules in the power plant, an identification ID for the solar modules, specification data for the solar modules, and a RAM section that allows for temporary storage erasure.

[0057] After interface 901 is connected to interface 120, when the user turns on the power to the diagnostic device 900, the work menu is displayed on monitor 905.

[0058] In this embodiment, for example, "Unification (Standardization) of IV Characteristics" is selected. When this task menu is selected, the next menu displays instructions such as "Please specify a reference module." The user specifies any ID from the reference module IDs. Once this is specified, the instructions "Measure the reference module in the STC environment and obtain the STC results" are displayed.

[0059] The user removes a desired solar cell module from the power plant, using it as a reference module, and obtains IV characteristic data using STC. This IV characteristic data under the STC environment is stored, for example, in a specific memory of the reference module.

[0060] The above-mentioned reference module is installed in its original location at the power plant. In this case, the light-receiving surfaces of the reference module and other measurement modules are cleaned. Next, the diagnostic device 900 is connected to a designated terminal at the power plant 100, and when the diagnostic device 900 is turned on, a question such as "Has the cleaning been completed?" is displayed on the monitor 905, and a comment such as "Please wait a while until the field IV characteristics of the reference module are obtained" is also displayed on the monitor 905. The waiting time may also be displayed.

[0061] After a certain period of time has elapsed, for example, a message indicating "measurement in progress" is displayed on the monitor 905, and based on the control of the system control unit 950, the diagnostic device 900 controls the conversion coefficient generator 921 and the IV characteristic estimator 922. Through this control, the processing described in Figures 7 and 8 is executed to obtain estimated IV characteristic data for other measurement modules.

[0062] The diagnostic device 900 stores this data in the memory 902, as well as in the storage devices of the corresponding measurement modules.

[0063] Figure 10 is a flowchart illustrating an example of the operation of a diagnostic device for adjusting solar cell modules. First, the diagnostic device 900 is connected to a predetermined interface of the solar power plant 100 and the power is turned on. At this point, a certain waiting time is set for the diagnostic device 900. After a certain time has elapsed, the diagnostic device 900 identifies a reference module and acquires reference IV characteristic data for this reference module (step SA1). It also acquires field IV characteristic data for the reference module (step SA2). Next, the coefficient (M,N) is acquired using the reference IV characteristic data and the field IV characteristic data (explained in Figure 7) (step SA3).

[0064] Next, data on the field IV characteristics of a measurement module different from the reference module is obtained (Step SA4). Then, the field IV characteristic data of the other measurement module is corrected using the coefficient (M,N) to obtain estimated reference IV characteristic data for the other measurement module (Step SA5).

[0065] Next, it is determined whether there are any other measurement modules that need to be corrected. If there are none (NO), the process of acquiring estimated criterion IV characteristic data is terminated. If there are others (YES), the process returns to step SA4.

[0066] The diagnostic device 900 may also include the following functions: that is, the process described in Figure 8 is performed according to the flowchart in Figure 10. In this case, depending on the measurement module, which may be severely degraded or malfunctioning, even if the field IV characteristic data is corrected, it may not be possible to obtain reference IV characteristic data measured under an ideal STC environment.

[0067] The diagnostic device 900 detects such measurement modules and displays a warning on the monitor 905 along with their identification data (ID). Administrators and users can see this warning and treat the measurement module as a replacement or reusable item.

[0068] The above warning display is used to show, either graphically or numerically, how much the estimated reference IV characteristics of the measurement module deviate from the actual reference IV characteristics.

[0069] Furthermore, this embodiment also incorporates the following improvements. In the explanations of Graph 701 in Figure 7 and Graph 801 in Figure 8, it was explained that field IV characteristics could be obtained immediately. However, due to changes in sunlight conditions, time of day, and environmental factors at the site (such as shadows and clouds), it is not always possible to obtain a smooth characteristic curve from short-circuit current to open-circuit voltage for all measurement modules. For this reason, in order to obtain field IV characteristics, the solar power plant may be operated in sections such as dawn, morning, afternoon, and evening, and the field IV characteristics may be acquired. Alternatively, the solar power plant may be operated at different times of the day. In such cases, the monitor control unit 904 shown in Figure 9 controls the monitor 905 so that the timing (date, time, etc.) at which sufficient field IV characteristics can be obtained is displayed on the monitor 905.

[0070] Figure 11 shows a further embodiment. In addition to the configuration of the judgment device 900 in Figure 9, it further includes a first detector 1011, a second detector 1012, and a third detector 1013. These first, second, and third detectors 1011, 1012, and 1013 are controlled by a system control unit 950.

[0071] The first detector 1011 calculates the maximum output power from the field IV characteristic data of each solar cell module and obtains determination data for solar cell modules that exhibit an output voltage below the first threshold. In other words, in this case, the solar cell module is, for example, a module that is significantly degraded and cannot obtain sufficient output power. The attribute information of this solar cell module (diagnosis result, identification number (ID, etc.)) is stored in the memory 902 as, for example, defective product data 9021.

[0072] The first threshold setting described above is configured to determine, for example, that solar modules with a service life of 10 years or less are defective if their output is below 80% of their rated output (e.g., 300W) (240W). However, the values ​​mentioned here are for reference only and may vary depending on the region and manufacturer.

[0073] The second detector 1012 calculates the maximum output power from the field IV characteristic data of each solar cell module, excluding defective products, and obtains determination data for solar cell modules whose maximum output power is greater than or equal to the first threshold and whose output power is below the second threshold. In this case, the attribute information (diagnosis result, identification number (ID), etc.) of the selected solar cell modules is stored in the memory 902 as, for example, reusable product data 9022.

[0074] The thresholds set above the first threshold and below the second threshold are such that, for example, for solar modules with a service life of 10 years or less, modules with a power output of 80% or more (240W or more) and around 90% (around 370W) of their rated output (e.g., 300W output) are judged as reusable. However, the values ​​mentioned here are for reference only and may vary depending on the region and manufacturer.

[0075] The third detector 1013 determines that the remaining items, after removing the previously identified defective and reusable items, are reusable good items, and the attribute information of those solar cell modules (diagnosis results, identification number (ID), etc.) is stored in memory 902 as reusable good item data 9023. However, for verification purposes, the output power of the solar cell module may be calculated and checked to see if it is above the second threshold. Reusable items and reusable good items may be grouped together and considered as good items.

[0076] The aforementioned defective product data 9021, reusable product data 9022, and reusable good product data 9023, that is, attribute information (which may also be called history information), include one or more so-called diagnostic information such as the identification number of the solar cell module, the identification name of the solar power plant in which it was used, the number of years of use, the number of diagnoses and the date of each diagnosis, the output watts (W) at the time of each diagnosis, and the location of the module at the power plant. Furthermore, if each solar cell module's junction box is provided with memory, attribute information about the solar cell module itself may be written to each memory from the diagnostic device 900.

[0077] The above attribute information (including defective product data 9021, reusable product data 9022, and reusable good product data 9023) can be sent to the desired recipient by the notification processor 1014 and can be used as a variety of service data.

[0078] The above-mentioned reusable item data 9022 and reusable good item data 9023 can be notified to businesses and others that have made offers to purchase the items. Furthermore, the reusable item data 9022 and reusable good item data 9023 can be sent to buyers (including intermediaries) and used as data for setting the purchase price of reusable items and reusable good items. In this case, the current output voltage value data may be sent as reference data along with the attribute information of the reusable item data 9022 and reusable good item data 9023.

[0079] Furthermore, defective product data 9021 can be used to notify repair companies and / or manufacturers, instructing them to investigate the cause of the defect. If the cause is identified, feedback information for the manufacture of the next product may be obtained. In this case, it is desirable that the above attribute information of the solar cell module (especially the manufacturer, years of use and usage history, and the diagnostic history mentioned above) is also notified to the repair company or manufacturer. Accordingly, there is a management data area for the solar cell modules used in the solar power plant within the memory, and the history data of each solar cell module is also managed there.

[0080] Furthermore, the defective product data 9021 described above is notified to the maintenance manager or contractor. This allows the manager or contractor to immediately replace the defective solar cell module with a new one. Thus, according to the above embodiment, it is possible to realize a data service that is extremely effective for the maintenance and management of solar power plants.

[0081] Although the output power compared to the threshold was described above assuming the use of field IV characteristics, either field IV characteristics or estimated reference IV characteristics may be used.

[0082] Furthermore, the manufacturer may be provided with all of the following: solar cell module history data, defective product data 9021, reusable product data 9022, reusable good product data 9023, and the reference IV characteristic data or field IV characteristic data and threshold data used for measurement.

[0083] In the above explanation, the device was described as one that categorizes the judgment data of other solar modules into judgment data for defective products 9021, reusable products 9022, and reusable good products 9023. However, it is not always necessary to make judgments on all three types of classification data. For example, judgment data could be divided into two categories: whether other solar modules belong to reusable good products or non-reusable products, or whether they belong to defective products or non-reusable products. Furthermore, judgment data with other classifications may be generated. For example, judgment data that determines whether other solar modules belong to reusable products or reusable good products could be created and used for service purposes.

[0084] The defective product data 9021, reusable product data 9022, and reusable good product data 9023 described above were explained as being stored in memory 902 during diagnosis. However, the operation to detect defective products may be performed automatically at a shorter interval than the diagnosis described above. The defective product data obtained at this time may be transmitted to a predetermined server, for example, using a wireless system (for example, transmitted to a relay agent and then via a network). In this case, the data manager on the server is configured to be accessible to the solar cell module manufacturer and / or maintenance company, and to monitor the defective product information described above. In this case as well, the manager or company can immediately replace the defective solar cell module with a new one.

[0085] Figure 12 shows that various data acquired by the diagnostic device 900 are transmitted from the wireless communication device of the notification processor 1014 of the diagnostic device 900, and then transmitted to the power plant management server 2500 via the repeater 2000 and the network NET for management.

[0086] Affiliated companies 2600 can view data in the power plant management server 2500 via the network NET. Affiliated companies 2600 include, in addition to the power company 2701, construction and cleaning companies 2702, defective product disposal companies 2703, reuse product handling companies 2704, solar power module manufacturers 2705, research and development departments 2706 for solar power modules and power generation systems, and weather information response departments 2707. This system allows the power plant management server 2500 to centrally hold data that many power plants need to manage. Many affiliated companies that need to refer to or use the data only need to access the power plant management server 2500, resulting in a streamlined overall system. Furthermore, the power plants themselves do not need to distribute and send data to their respective management companies.

[0087] Each affiliated company can check the data in the power plant management server 2500 (such as the attribute information described earlier) and perform maintenance on the power plant. For example, construction and cleaning company 2701 can detect solar modules with abnormally low power output, consult with the power plant manager, and propose cleaning or replacement work. Defective product disposal company 2703 and reuse product handling company 2704 can monitor the aforementioned defective product data and reusable product data, consult with the power plant manager, and take on the responsibility of collecting or purchasing defective or reusable solar power modules.

[0088] Furthermore, manufacturers 2705 and research and development departments 2706 can, for example, monitor diagnostic information of solar cell modules they have manufactured or researched and developed, and can also take back defective solar cell modules to investigate the cause of failures.

[0089] The weather information response unit 2707 can transmit weather information for the area of ​​the solar power plant to the power plant management server 2500 and add it to the management data (attribute information, etc.) of the corresponding solar power plant. This can sometimes help identify the cause of solar power module failures or factors contributing to reduced output.

[0090] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. Furthermore, even if each component of a claim is expressed by dividing it, by combining multiple components, or by combining them, it remains within the scope of the present invention. Multiple embodiments may also be combined, and embodiments composed of such combinations also fall within the scope of the invention.

[0091] Furthermore, drawings may schematically represent the width, thickness, shape, etc., of each part compared to the actual embodiment in order to make the explanation clearer. Also, the apparatus of the present invention is applied even when the claims are expressed as control logic, as a program including instructions for a computer to execute, or as a computer-readable recording medium on which such instructions are written. Moreover, the names and terms used are not limited, and other expressions are included in the present invention if they are substantially the same in content and intent. [Explanation of symbols]

[0092] 100...Solar power plant, 101, 102...Solar cell module (measurement module), 103...Solar cell module (reference module), 200...Measurement station, 210...Measuring instrument, 105...Solar cell module, 211, 212, 213...IV characteristic measuring instrument, 701, 702, 703, 801, 802, 803...Graph, Lo...Field IV characteristics, Lo1...Current adjustment IV characteristics, Lo2...Voltage adjustment IV characteristics, St...Reference IV characteristics, Lo11...Field IV characteristics, Lo21...Current adjustment IV characteristics, Lo22...Voltage adjustment IV characteristics, 900...Diagnostic device, 901...Interface, 902...Memory, 903...Operation unit, 904...Monitor control unit, 905...Monitor, 921...Conversion coefficient generator, 922...IV characteristic estimator, 950...System control unit, 9021...Defective product data, 9022...Reusable product data, 9023...Reusable good product data, 1010...First detector, 1012...Second detector, 1013...Third detector.

Claims

1. A method for diagnosing other solar cell modules at a solar power plant, wherein one or more solar cell modules are transported from the solar power plant to a measurement location that satisfies STC (Standard Measurement Conditions), a reference reference IV characteristic is measured at the measurement location, and the data of that reference IV characteristic is obtained, and the solar cell module used as the reference module is used. With the reference module returned to its original location at the solar power plant, The field IV characteristics of the reference module returned to its original location are measured, and a conversion coefficient, which is the difference between the field IV characteristics and the reference IV characteristics, is determined. A method for diagnosing a solar cell module, comprising determining the reference IV characteristics of the other solar cell module from the field IV characteristics of the other solar cell module using the conversion coefficient.

2. The method for diagnosing a solar cell module according to claim 1, wherein the reference module returned to its original location is selected from among several solar cell modules, the one whose IV characteristics measured by the STC are closest to those of the specifications at the time of shipment.

3. The method for diagnosing solar cell modules according to claim 1, wherein the multiple solar cell modules are manufactured products with the same specifications.

4. Includes a monitor control device and a monitor controlled by this monitor control device, The method for diagnosing a solar cell module according to claim 1, further comprising displaying a comment on whether the light-receiving surface of the other solar cell module was cleaned before the field IV characteristics of the reference module were measured.

5. A data service method for diagnostic results, comprising: calculating the output power of the other solar cell module from the field IV characteristics or estimated reference IV characteristics of the other solar cell module diagnosed by the diagnostic method of claim 1; setting a threshold for the output power; and obtaining determination data that determines whether the other solar cell module belongs to a good product or an ineligible product.

6. The diagnostic result data service method according to claim 5, which obtains determination data that determines whether the good product belongs to a reusable product or a reusable good product.

7. The diagnostic result data service method according to claim 5, wherein when the judgment data is notified to an external party by a notification processor, the judgment data of good products is notified to the purchasing company.

8. The diagnostic result data service method according to claim 5, wherein when the aforementioned determination data is notified externally by a notification processor, the determination data of the items other than those specified is notified to one or more of the repair company, manufacturer, or maintenance personnel.

9. A diagnostic device for other solar cell modules at a solar power plant, in which one or more solar cell modules are transported from the solar power plant to a measurement location that satisfies STC (Standard Measurement Conditions), a reference reference IV characteristic is measured at the measurement location, and the data of the reference IV characteristic is obtained from the solar cell module used as the reference module, With the reference module returned to its original location at the solar power plant, The diagnostic device is A conversion coefficient generator that measures the field IV characteristics of the reference module returned to its original location and calculates the conversion coefficients M and N, which are the differences between the field IV characteristics and the reference IV characteristics. A diagnostic device for solar cell modules, comprising: an IV characteristic estimator that determines the reference IV characteristics of the other solar cell modules from the field IV characteristics of the other solar cell modules using the conversion coefficient; and

10. The solar cell module diagnostic device according to claim 9, wherein the light-receiving surfaces of the solar cell module and the other solar cell module are cleaned before the field IV characteristics are measured.

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