Novel Photovoltaic Micro Crack Detection Technique

Abstract

This paper presents a novel detection technique for inspecting solar cells micro cracks. Initially, the solar cell is captured using Electroluminescence (EL) method, then processed by the proposed technique. The technique consist of three stages, the first stage combines two images, the first image is the crackfree (healthy) solar cell, whereas the second is the cracked solar cell image. Both output images processed into a bit-by-bit gridding technique, which enables the detection of all bits in the considered area of the cracked solar cell. The second stage uses an OR gate between each of the examined bits for both healthy and cracked solar cells. The final calibrated image presents a high quality, and low noise structure, thus easier to identify the micro crack size, location and its orientation. In order to examine the effectiveness of the proposed technique, three different cracked PV solar cells have been examined. The results show that the micro cracks size, orientation, and location is more visible using the proposed technique. In addition, the developed technique has been validated using a full scale PV module, and compared with up to date available PV micro crack detection methods.

A Comprehensive Evaluation on Types of Microcracks and Possible Effects on Power Degradation in Photovoltaic Solar Panels

“…Mahmoud Dhimish et al [31] presented a new technique for µcracks inspection in solar cells, by capturing the image of solar cells using the EL method, and then, use the proposed technique that consists of three stages to identify the µcracks size, location and its orientation. The developed technique has been validated using a full-scale PV module, and compared with up to date available PV µcrack detection methods.…”

“…The international standard IEC60904-09 is enforced concerning light spectrum, irradiance, non-uniformity, and short-term instability (STI), as shown in Table 2 [33]. The Xenon technology spectrum is continuous, from 300 nm up to 1200 nm, and the total cycle time used for testing in this study was 30 s. The measurements followed the IEC 61215-2 norms [31], where the panel is loaded into class AAA flasher and a reference PV device is used as a reference panel of the same size with the same cell technology, to match spectral responsivity as per the IEC60904-2 norms. Then, the current-voltage characteristics of the panel are measured in accordance with the IEC60904-1 standard, at a specific set of irradiance and temperature conditions [34].…”

Ultrafast High-Resolution Solar Cell Cracks Detection Process

“…The inspected solar cell samples, after passing though the calibration mode discussed earlier in section III, the yielded image of the solar cell will be passed into a plot profile mapping. The plot profile measures the distance in pixels vs. the gray level of the image [19]; gray level corresponds to the dark areas/zones of the perceived solar cell image [20].…”

Development of Novel Solar Cell Micro Crack Detection Technique

“…After examining the solar cell using the proposed inspection method discussed earlier in section III, the final calibrated image of the solar cell will be processed using the plot profile method which is well known as the distance in pixels vs. the gray level (the level of the dark spots at specific x-axis distance) [26].…”