Three major types of problem detection methods for photovoltaic modules

 

The photovoltaic module is the core component of photovoltaic power generation. In order to operate the photovoltaic power station normally, it is necessary to inspect and maintain the components of the photovoltaic power plant. Common problems with photovoltaic modules are: hot spots, cracks, and power attenuation. Since these quality problems are hidden inside the panel, or after the PV power plant is operated for a period of time, it is difficult to identify when the panel is in the field of acceptance, and it is necessary to use professional equipment for PV module inspection.

 

Causes of hot spot formation and detection methods of photovoltaic modules

 

The hot spot of the photovoltaic module means that the component is not exposed to sunlight due to the sunlight, so that the covered part heats up much more than the uncovered part, causing the burnt dark spot to be overheated.

 

The formation of hot spots in photovoltaic modules is mainly composed of two intrinsic factors, namely internal resistance and dark current of the cell itself.

 

The hot spot endurance test is a test for a photovoltaic module to determine the ability of a solar cell module to withstand the hot spot heating effect. The photovoltaic cell module is tested by a reasonable time and process to indicate that the photovoltaic cell can be used for a long period of time under specified conditions.

 

Hot spot detection can be detected by an infrared camera. The infrared camera can use thermal imaging technology to display the measured target temperature and its distribution in a visible heat map.

 

Causes of crack formation and detection methods of photovoltaic modules

 

The crack is a small crack in the battery. The crack of the battery will accelerate the power attenuation of the battery and affect the normal service life of the component. At the same time, the crack of the battery will expand under the mechanical load, which may cause open circuit damage. Cracking can also cause hot spot effects. The occurrence of cracks is caused by a combination of various reasons. The uneven force of the components or the sharp shaking during transportation and reversal may cause cracks in the battery sheets.

 

The PV module is tested for EL imaging before leaving the factory, and the instrument used is an EL detector. The instrument utilizes the electroluminescence principle of crystalline silicon to capture the near-infrared image of the component using a high-resolution CCD camera to acquire and determine component defects. The EL detector is capable of detecting the presence or absence of cracks, debris, solder joints, broken gates, and abnormalities of single-cell batteries with different conversion efficiencies.

Three major types of problem detection methods for PV modules Quickly collect them Power attenuation classification and PV module detection methods Photovoltaic module power attenuation refers to the phenomenon that the output power of components decreases gradually with the increase of illumination time. The power attenuation of photovoltaic modules can be roughly divided into three categories: the first category, component power attenuation due to destructive factors; the second category, the initial photoinduced attenuation of components; the third category, the aging attenuation of components. Among them, the first type is the controllable attenuation during the installation of photovoltaic modules. For example, strengthening the unloading, reversing, and installation quality control of photovoltaic modules can reduce the probability of cracking and fragmentation of component cells. The second and third categories are the technical problems that need to be solved in the production process of photovoltaic modules. PV module power attenuation testing can be done with the PV module I-V characteristic curve tester.

Three major types of problem detection methods for photovoltaic modules

 

Power attenuation classification and photovoltaic module detection method

 

PV module power attenuation refers to the phenomenon that the output power of the component gradually decreases as the illumination time increases. The power attenuation of photovoltaic modules can be roughly divided into three categories:

 

In the first category, component power attenuation due to destructive factors;

 

The second category, the initial photoinduced attenuation of the component;

 

In the third category, the aging of components is attenuated.

 

Among them, the first type is the controllable attenuation during the installation of photovoltaic modules. For example, strengthening the unloading, reversing, and installation quality control of photovoltaic modules can reduce the probability of cracking and fragmentation of component cells.

 

The second and third categories are the technical problems that need to be solved in the production process of photovoltaic modules. PV module power attenuation testing can be done with the PV module I-V characteristic curve tester.