JP6208843B1 - Solar cell panel inspection apparatus and solar cell panel inspection method - Google Patents

Abstract

To provide an EL inspection apparatus for a solar cell panel that can be used quickly and easily outdoors. An inspection apparatus 100 for a solar cell panel M using electroluminescence (EL), an AC power source 10 for generating AC power for applying an AC current to the solar cell panel M, and a solar cell panel M The AC power is set so that the AC impedance for inducing EL light emission in the solar cell panel is 1 kΩ or more. [Selection] Figure 1

Description

  The present invention relates to a solar cell panel inspection apparatus and a solar cell panel inspection method using electroluminescence (EL).

  In recent years, solar power generation using sunlight, which has an inexhaustible energy source, has attracted attention due to the growing interest in clean energy that is environmentally friendly. In order to supply long-term stable energy by solar power generation, it is necessary to periodically inspect the solar cell panel used for power generation for defects.

  In the inspection of the solar cell panel, the presence or absence of defects such as “cracks (including microcracks)” and “disconnection” is usually confirmed. An EL inspection method using electroluminescence (EL) is known as one of methods for inspecting the presence or absence of defects in a solar cell panel. In general, when predetermined energy is given to a semiconductor, light is generated when excited electrons in the semiconductor transition to a ground state. Here, the method of applying the predetermined energy by electric energy is referred to as electroluminescence (EL). In an EL inspection of a solar battery panel, when a current having energy larger than the forbidden band width is applied to a solar battery cell that is a semiconductor, electrons and holes are generated in the semiconductor, and light is emitted when they are recombined. At this time, if there are defects or impurities in the semiconductor crystal, these defects affect the recombination process of electrons and holes formed when electric energy is applied, and the semiconductor crystal is more than a normal crystal. Also emits light (EL light) with low intensity energy. Using this phenomenon, it is possible to detect defects in the solar cell panel from information obtained by EL emission.

  Usually, a solar cell panel is installed in a place with little influence of shade in order to use sunlight efficiently. For example, when installing a solar cell panel in a building, it is installed at a high place such as a rooftop. Moreover, when installing a solar cell panel in vehicles, such as a motor vehicle, it installs on a roof or a bonnet. Since the solar cell panel is not supposed to be removed once installed, it is desired that the solar cell panel can be inspected quickly and easily on site.

  So far, the present applicant has developed an EL inspection device having a function of correcting a photographed image as a solar cell panel inspection device (see, for example, Patent Document 1). The solar cell panel inspection apparatus of Patent Document 1 was developed mainly for inspecting recent large-sized solar cell panels, and as a configuration therefor, a DC power source that induces EL emission in the solar cell panel and And a camera having a short-focus wide-angle lens capable of collectively photographing the entire inspection surface of the solar battery panel.

International Publication No. 2011/152445

  The EL inspection apparatus for solar cell panels of Patent Document 1 assumes that solar cell panels are continuously inspected by an in-line method. That is, this inspection apparatus continuously inspects the solar cell panel before shipment in the dark room by the EL method. Therefore, when performing EL inspection, inspection conditions under which strong EL emission is induced are desirable so that defects of the solar cell panel can be found with high accuracy. Further, as in Patent Document 1, when a solar cell panel is inspected in an inspection room, an inspection environment can be prepared in advance, so that there are few restrictions on equipment when performing the inspection. Incidentally, in Patent Document 1, a DC power source is used as a power source for inducing EL emission in a solar cell panel to be inspected, and this is provided as a dedicated facility for an EL inspection apparatus.

  On the other hand, in the inspection of solar cell panels that are already installed outdoors, high-accuracy inspection as inspecting products before shipment may not be necessary, but rather, it is required that inspection can be performed quickly and easily. ing. However, inspection of outdoor solar cell panels cannot always be performed under the same conditions and environment, and may be forced to be performed in environments where infrastructure is not established or in harsh conditions. In particular, in the inspection by the EL method, it is important to secure facilities necessary for the inspection of the power source and the like at the site, and an EL inspection apparatus that can be used quickly and easily in any situation is desired.

  The present invention has been made in view of the above problems, and an object thereof is to provide a solar cell panel EL inspection apparatus and a solar cell panel EL inspection method that can be used quickly and easily outdoors.

The characteristic configuration of the inspection apparatus for solar cell panel according to the present invention for solving the above problems is as follows.
An inspection device for a solar cell panel using electroluminescence (EL),
An AC power source for generating AC power for applying AC to the solar cell panel;
A camera for photographing the surface of the solar cell panel;
With
The AC power is set such that an AC impedance for inducing EL emission in the solar cell panel is 1 kΩ or more.

The solar cell panel itself is a semiconductor product, and is configured to allow only a current in a specific direction to pass therethrough. In addition, a bypass diode is connected to the solar cell panel in order to prevent heat generation or the like that may occur at the time of abnormality. Normally, no current flows through the bypass diode, but when the resistance of the solar panel bus bar is removed, for example, by increasing the resistance, the current is diverted from the interconnector to the bypass diode circuit, and the solar panel's Wiring is prevented from overheating.
According to the solar cell panel inspection apparatus of this configuration, since an inspection is performed by applying an alternating current to the solar cell panel, a commercial power source can be used as an AC power source. In this case, the AC power generated by the AC power source is set so that the AC impedance for inducing EL light emission in the solar cell panel is 1 kΩ or more. Therefore, the current flowing in a specific direction is used to inspect the solar cell panel. Necessary degree of EL emission can be induced. Since the solar cell panel inspection apparatus of the present configuration that can use such a commercial power supply is excellent in convenience, it can quickly and easily inspect solar cell panels that are already installed outdoors.

In the solar cell panel inspection apparatus according to the present invention,
It is preferable that the AC impedance is set to be 3 kΩ or more.

  According to the solar cell panel inspection apparatus of this configuration, since the impedance of alternating current that induces EL emission in the solar cell panel is set to be 3 kΩ or more, a reverse half wave may flow in the power generation circuit. While preventing reliably, EL light emission sufficient for the inspection of a solar cell panel can be induced by a current flowing in a specific direction.

In the solar cell panel inspection apparatus according to the present invention,
The AC power supply is preferably an AC generator that generates AC power with an output of 100V or 200V.

  According to the solar cell panel inspection apparatus of this configuration, the same power as a general household power supply (commercial power supply) can be supplied by using an AC generator that generates 100V or 200V AC power as the AC power supply. It becomes. Therefore, if there is a normal outlet, the inspection can be performed quickly and easily at any place.

In the solar cell panel inspection apparatus according to the present invention,
The circuit further comprises a circuit inspection unit in which a first LED that passes a forward current and a second LED that passes a reverse current are connected in parallel.
It is preferable that the solar cell panel to be inspected is arranged between the AC power supply and the circuit inspection unit during the inspection of the solar cell panel.

  According to the inspection device of the solar cell panel of this configuration, a circuit inspection unit is used in which a first LED that passes a forward current and a second LED that passes a reverse current are connected in parallel. By placing the solar cell panel to be inspected between the AC power supply and the circuit inspection unit, the state (normal / failure) of the solar cell panel is reflected in the lighting state of the first LED and the second LED. The occurrence location can be specified, and as a result, in addition to being able to inspect quickly and easily, a more accurate inspection result can be obtained.

In the solar cell panel inspection apparatus according to the present invention,
The solar cell panel is preferably a solar cell module in which a plurality of solar cells are connected.

  According to the solar cell panel inspection apparatus of this configuration, since the solar cell panel is usually commercialized as a solar cell module to which a plurality of cells are connected, it is possible to inspect most types of solar cell panels that are sold. It can be performed.

In the solar cell panel inspection apparatus according to the present invention,
The solar cell panel is a single crystal silicon solar cell, a polycrystalline silicon solar cell, or a CIGS {copper-indium-gallium-selenium} -based compound solar cell. Is preferred.

  According to the solar cell panel inspection apparatus of this configuration, it is possible to cope with the inspection of the various types of solar cell panels described above.

The characteristic configuration of the method for inspecting a solar cell panel according to the present invention for solving the above problems is as follows.
A method for inspecting a solar cell panel using electroluminescence (EL),
A current application step of applying alternating current to the solar cell panel;
A photographing step of photographing the surface of the solar cell panel;
With
In the current application step, an AC impedance for inducing EL emission in the solar cell panel is set to 1 kΩ or more.

  According to the method for inspecting a solar cell panel of this configuration, the same excellent operational effects as those of the above-described solar cell panel inspection device can be achieved. That is, when an alternating current is applied to the solar cell panel, the impedance is set to be 1 kΩ or more, so that the EL light emission necessary for the inspection of the solar cell panel is induced by the current flowing in a specific direction. Can do. And according to such a test | inspection method, since a commercial power source can be utilized, it is excellent in convenience and can test | inspect quickly and simply about the solar cell panel already installed outdoors.

FIG. 1 is an explanatory diagram of a solar cell panel inspection apparatus according to a first embodiment of the present invention. FIG. 2 is an explanatory diagram relating to the solar cell panel. FIG. 3 is an explanatory diagram regarding inspection of a solar cell panel. FIG. 4 is a graph showing the relationship between impedance and frequency measured when alternating current is applied to various types of solar cell panels. FIG. 5 is an explanatory diagram of a solar cell panel inspection apparatus according to the second embodiment of the present invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments relating to a solar cell panel inspection apparatus of the present invention will be described with reference to FIGS. The solar cell panel inspection method of the present invention will be described in the solar cell panel inspection apparatus. However, the present invention is not intended to be limited to the configurations described in the embodiments and drawings described below.

[First embodiment]
FIG. 1 is an explanatory view of a solar cell panel inspection apparatus (hereinafter simply referred to as “inspection apparatus”) 100 according to a first embodiment of the present invention. The inspection apparatus 100 inspects the solar cell panel M using electroluminescence (EL) generated when electric energy is applied to a semiconductor. The solar cell panel M is generally configured as a solar cell module in which a plurality of solar cells S are connected. The inspection apparatus 100 of the present invention can be used for, for example, inspection of a solar battery panel as a solar battery module in which 48 to 72 solar battery cells are connected in series. In particular, 60 or 72 solar batteries are used. It is suitable for inspection of a solar battery panel composed of battery cells. As the solar cell panel M to be inspected, for example, a single crystal silicon type solar cell, a polycrystalline silicon type solar cell, CIGS {copper (copper) -indium (indium) -gallium (gallium) -selenium (Selenium)} compound A solar cell etc. are mentioned.

  The inspection apparatus 100 of the present invention includes an AC power supply 10 that generates AC power for applying AC to the solar cell panel M, and a camera 20 that photographs the surface of the solar cell panel M. A current application step of applying alternating current to the solar cell panel is performed by the AC power source 10, and a photographing step of photographing the surface of the solar cell panel is performed by the camera 20.

  Unlike the conventional EL inspection apparatus exemplified in Patent Document 1 described above, the inspection apparatus 100 of the present invention is characterized by using an AC power supply 10 as a power source. As the AC power source 10, an AC generator can be used in addition to the commercial power source. The type, performance, and the like of the AC generator are not particularly limited, but an AC generator that generates AC power with an output of 100 V or 200 V is preferable in terms of versatility, cost, and availability. With such an AC generator, the same AC power (50 Hz or 60 Hz) as that of the commercial power source can be generated. That is, by using an alternator, the same power as a general household power supply (commercial power supply) can be supplied. Therefore, if there is a normal outlet, the solar power can be quickly and easily provided at any location. The battery panel M can be inspected.

  Here, in order to induce the EL light emission to the extent necessary for the inspection when the EL inspection of the solar cell panel M is performed, the AC power supply 10 depends on the solar cell panel M to be inspected. It is necessary to grasp the relationship between the frequency of alternating current applied to the solar cell panel M and the impedance. Therefore, the following consideration was made on the above relationship.

  FIG. 2 is an explanatory diagram relating to the solar cell panel M. FIG. FIG. 2A is a schematic configuration diagram of the solar cell panel M. FIG. As described above, the solar cell panel M is configured as a solar cell module in which a plurality of cells S are connected in series, and a desired number of solar cell panels M are connected in series. FIG. 2A illustrates four solar cell panels M. Each cell S constituting each solar cell panel M is formed by joining an n-type semiconductor containing many negatively charged electrons and a p-type semiconductor containing many positively charged holes. When holes enter the n-type semiconductor, they combine with electrons. Similarly, when electrons enter the p-type semiconductor, they combine with holes. Thus, when the n-type semiconductor and the p-type semiconductor are joined, a region called a depletion layer having no electrons or holes is formed on the joint surface. An electric field is generated in the depletion layer. When sunlight enters the depletion layer, the light is absorbed by the semiconductor to generate electrons and holes, which are pushed out by the electric field and flow as current to the external circuit. This series of mechanisms is power generation. The current generated by the solar cell panel M is a direct current, and it is necessary to convert it into an alternating current in order to use it as electricity. As shown in FIG. 2A, each wiring of the solar cell panel M is concentrated in the connection box 1, and the connection box 1 is further connected to the power conditioner 2. The direct current generated by the solar cell panel M is converted into alternating current by the power conditioner 2 and used as power in factories, offices, residences, and the like.

  FIG. 2B is an equivalent circuit diagram of one cell S constituting the solar battery panel M. The configuration of the entire solar cell panel M is as described above. However, when considered in terms of an electric circuit diagram, one cell S constituting the solar cell panel M has a constant current source (as shown in FIG. 2B). I component), parallel diode (D component), series resistance (Rs component), and parallel resistance (Rsh component). Although the solar cell panel M has a module structure in which the cells S are connected in series, it can be considered that the equivalent circuit shown in FIG. Accordingly, the equivalent circuit diagram of the solar cell module can be expressed as the equivalent circuit diagram of FIG. 2B, as in the case of one cell S, although the values of the components such as the series resistance change.

  FIG. 3 is an explanatory diagram relating to the inspection of the solar cell panel M. FIG. FIG. 3A is a diagram showing the flow of alternating current waves when alternating current is applied to the solar cell panel M. FIG. FIG. 3B is a substantial equivalent circuit diagram derived from FIG. As described above, a depletion layer is formed in the cell S and an electric field is generated. When alternating current is applied here, the alternating current wave captures the depletion layer as a capacitor that can store electric charge, so that capacitive reactance (C component) can be expressed in the equivalent circuit diagram as shown in FIG. . And as shown by the arrow in Fig.3 (a), an alternating current wave does not pass parallel resistance (Rsh component), but passes a capacitor | condenser with a large electrical capacitance. That is, the power generation circuit of the solar cell panel M functions as a kind of diode, and in FIG. 3A, the inductive reactance (L component), series resistance (Rs component), and capacitive part shown by the solid line in FIG. It will pass through the reactance (C component). Therefore, as shown in FIG. 3B, the equivalent circuit diagram when an AC wave is input to the solar panel M is substantially a series resistance (Rs component), an inductive reactance (L component), and a capacitive property. This is an equivalent circuit diagram represented by reactance (C component).

  When expressed as an equivalent circuit diagram as shown in FIG. 3B, when Z is impedance (Ω), R is resistance (Ω), and ω is angular frequency (rad / s), the following equation (1) is obtained. It holds.

  In the formula (1), the angular frequency ω means the following formula (2).

  In equation (1), if the impedance Z is equal to or greater than a certain value, the bias current (reverse half wave) does not flow in the power generation circuit of the solar panel M, but the current flowing in a specific direction (forward half wave) EL light emission sufficient for the inspection of the solar cell panel M can be induced. For this purpose, the value of ω (that is, frequency f) needs to be appropriately selected according to the type of solar cell panel M. Therefore, the impedance Z of various solar cell panels M is measured by the equations (1) and (2) while changing the AC frequency f, and the relationship between the AC frequency f and the impedance Z applied to the solar cell panel M is determined. Revealed.

  FIG. 4 is a graph showing the relationship between impedance Z and frequency f measured when alternating current is applied to various solar cell panels. In FIG. 4, (a) a single crystal silicon solar cell (6 inches, 60 cells), (b) a polycrystalline silicon solar cell (6 inches, 60 cells), (c) a thin film CIGS compound solar cell (solar Frontier Corporation solar cell module Product name: SF145-K) shows the impedance Z measured when the frequency f of alternating current applied to each solar cell panel is changed from 42 Hz to 5 MHz. (A) In the single crystal silicon type solar cell, when the AC frequency was 1000 Hz or less, the AC impedance was 1 kΩ or more. In this case, EL light emission required for the inspection is induced in the solar cell panel M, and the EL inspection can be surely performed. Similarly, in (b) a polycrystalline silicon type solar cell, the AC frequency is desirably 1000 Hz or less, and (c) in a thin film type CIGS compound solar cell, the AC frequency may be 20000 Hz or less. It turns out to be desirable. Regardless of the type of solar cell panel M, in order to perform the EL inspection with certainty, the AC power generated from the AC power supply 10 is preferably set so that the AC impedance is 3 kΩ or more. . In this case, it is possible to reliably prevent a reverse half wave from flowing through the power generation circuit of the solar cell panel M, and it is possible to induce EL emission sufficient for the inspection of the solar cell panel M by a current flowing in a specific direction.

  As shown in FIG. 1, the solar cell panel M to which alternating current is applied by the alternating current power supply 10 is photographed for the EL emission state of the inspection surface using the camera 20. In FIG. 1, the camera 20 is depicted as being disposed on the side of the solar cell panel M due to the space on the paper, but in reality, the camera 20 is disposed on the front surface of the solar cell panel M. The whole surface of the solar cell panel M can be photographed. By comparing the EL emission image of the solar panel M taken with the camera 20 with the EL emission image of the normal solar panel M taken in advance, defects such as cracks and disconnections can be recognized. .

  The camera 20 is not particularly limited as long as it has sensitivity to the EL emission wavelength, but a digital camera equipped with a light receiving element such as a CCD sensor or a CMOS sensor can be preferably used. The photographing of the solar battery panel M by the camera 20 is usually performed by an inspector directly operating the shutter of the camera 20, but the camera 20 is connected to a wireless LAN or IEEE 802.15.1 (so-called Bluetooth (registered trademark)). ) Through a portable information communication device (smart phone, tablet terminal, etc.), and the shutter operation can be performed by the portable information communication device. In addition, when the shooting environment is severe, such as when the solar cell panel 20 to be inspected is at a high place, the camera 20 is mounted on a small unmanned aircraft (such as a drone), and the shutter operation is performed remotely together with a portable information communication device. It is also possible to do this.

  The camera 20 may have an image processing function. For example, by subtracting a background image including noise from an image captured by the camera 20, it can be processed into an EL emission image with reduced noise. In this way, by performing an appropriate process on the photographed image, a clear processed image that can be used for determining a defect on the inspection surface of the solar cell panel M can be obtained. Note that when the image captured by the camera 20 is clear, it is not necessary to perform image processing of the captured image. Therefore, the image processing function of the camera 20 is an arbitrary configuration that may be provided as necessary.

  As described above, according to the inspection apparatus 100 of the first embodiment, the solar battery panel M can be inspected quickly and easily by including the AC power supply 10 and the camera 20.

[Second Embodiment]
FIG. 5 is an explanatory view of a solar cell panel inspection apparatus (hereinafter simply referred to as “inspection apparatus”) 200 according to the second embodiment of the present invention. The inspection device 200 is obtained by adding a circuit inspection unit 30 for inspecting a power generation circuit or a bypass diode circuit to the inspection device 100 of the first embodiment. Therefore, since the AC power supply 10 and the camera 20 are the same as those of the inspection apparatus 100 of the first embodiment, description thereof will be omitted.

  The circuit test | inspection part 30 connects the 1st LED31 and the 2nd LED32 in parallel via the transformer. Here, the first LED 31 and the second LED 32 are arranged so that their current passing directions are opposite to each other. By arranging in this way, only the AC wave (a positive voltage half-wave) that returns from the AC power supply 10 to the AC power supply 10 through the power generation circuit of the solar cell panel M can pass through the first LED 31. it can. On the other hand, only the AC wave (a negative voltage half-wave) that returns from the AC power supply 10 to the AC power supply 10 through the bypass diode circuit of the solar cell panel M can pass through the second LED 32.

  When the solar cell panel M is inspected, as shown in FIG. 5, the solar cell panel M to be inspected is disposed between the AC power supply 10 and the circuit inspection unit 30. By setting it as such arrangement | positioning, since the state (normal / failure) of the solar cell panel M is reflected in the lighting state of the 1st LED31 of the circuit test | inspection part 30, and the 2nd LED32, it is possible to specify an abnormality occurrence location. It becomes possible. Specifically, the states of the power generation circuit and the bypass diode circuit of the solar cell panel M can be determined from the following four lighting patterns.

(1) First LED: lighting / second LED: lighting In this case, the first LED 31 has an AC wave (plus voltage) that returns from the AC power supply 10 through the power generation circuit of the solar panel M to the AC power supply 10 again. Half-wave). In addition, an AC wave (a half wave of a negative voltage) returning from the AC power supply 10 to the AC power supply 10 through the bypass diode circuit of the solar battery panel M passes through the second LED 32. Therefore, when both the first LED 31 and the second LED 32 are lit, it can be determined that both the power generation circuit and the bypass diode circuit of the solar cell panel M are normal.

(2) First LED: On / Second LED: Off In this case, the first LED 31 has an AC wave (plus voltage) that returns from the AC power source 10 through the power generation circuit of the solar panel M to the AC power source 10 again. Half-wave). On the other hand, the second LED 32 does not pass an AC wave (a negative voltage half-wave) returning from the AC power supply 10 through the bypass diode circuit of the solar battery panel M to the AC power supply 10 again. Therefore, when the first LED 31 is turned on and the second LED 32 is turned off, it can be determined that the bypass diode circuit of the solar panel M is abnormal.

(3) First LED: Off / Second LED: On In this case, the first LED 31 has an AC wave (plus voltage) that returns from the AC power supply 10 through the power generation circuit of the solar panel M to the AC power supply 10 again. The half wave) is not passing. On the other hand, the second LED 32 passes an AC wave (a negative voltage half-wave) returning from the AC power supply 10 through the bypass diode circuit of the solar battery panel M to the AC power supply 10 again. Therefore, when the first LED 31 is turned off and the second LED 32 is turned on, it can be determined that the power generation circuit of the solar cell panel M is abnormal.

(4) First LED: Off / Second LED: Off In this case, neither the first LED 31 nor the second LED 32 passes an AC wave from the AC power supply 10. Therefore, when the first LED 31 is turned off and the second LED 32 is turned off, it can be determined that both the bypass diode circuit and the power generation circuit of the solar cell panel M are abnormal.

  As described above, according to the inspection apparatus 200 of the second embodiment, in addition to the AC power supply 10, the camera 20, and the inspection circuit unit 30, the solar cell panel M can be inspected quickly and easily. Thus, it is possible to accurately identify the abnormality occurrence location in the solar cell panel M.

  The solar cell panel inspection apparatus and solar cell panel inspection method of the present invention are used for solar cell inspection, but solar cells can be used as long as they can be inspected by electroluminescence (EL). It is also possible to use it for inspection of other devices.

10 AC power supply 20 Camera 30 Circuit inspection part 31 First LED
32 Second LED
100 Inspection Device 200 Inspection Device S Solar Cell M Solar Panel (Solar Cell Module)

Claims (7)

An inspection device for a solar cell panel using electroluminescence (EL),
An AC power source for generating AC power for applying AC to the solar cell panel;
A camera for photographing the surface of the solar cell panel;
With
The alternating current power is set so that an alternating current impedance for inducing EL emission in the solar cell panel is 1 kΩ or more, and by applying the alternating current, a forward current flows in the power generation circuit of the solar cell panel, A solar cell configured such that a forward current and a reverse current flow alternately in the solar cell panel when a reverse current flows through a bypass diode connected in parallel with the power generation circuit of the solar cell panel Panel inspection device.   The solar cell panel inspection apparatus according to claim 1, wherein the AC impedance is set to be 3 kΩ or more.   The solar cell panel inspection apparatus according to claim 1, wherein the AC power supply is an AC generator that generates AC power having an output of 100 V or 200 V. The circuit further comprises a circuit inspection unit in which a first LED that passes a forward current and a second LED that passes a reverse current are connected in parallel.
The solar according to any one of claims 1 to 3, wherein a solar cell panel to be inspected is arranged between the AC power source and the circuit inspection unit during the inspection of the solar cell panel. Battery panel inspection device.   The solar cell panel inspection apparatus according to any one of claims 1 to 4, wherein the solar cell panel is a solar cell module in which a plurality of solar cells are connected.   The solar cell panel may be a single crystal silicon solar cell, a polycrystalline silicon solar cell, or a CIGS {copper-indium-gallium-selenium} compound solar cell. Item 6. The solar cell panel inspection apparatus according to any one of Items 1 to 5. A method for inspecting a solar cell panel using electroluminescence (EL),
A current application step of applying alternating current to the solar cell panel;
A photographing step of photographing the surface of the solar cell panel;
With
In the current application step, an alternating current impedance for inducing EL emission in the solar cell panel is set to 1 kΩ or more, and by applying the alternating current, a forward current flows through the power generation circuit of the solar cell panel, and the solar cell A method for inspecting a solar cell panel , wherein a forward current and a reverse current flow alternately in the solar cell panel when a reverse current flows through a bypass diode connected in parallel with the power generation circuit of the panel .

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