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 the electroluminescence (EL) method, then processed by the proposed technique. The technique consists of three stages: the first stage combines two images, the first image is the crack-free (healthy) solar cell, whereas the second is the cracked solar-cell image. Both output images are 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 examined bit for both healthy and cracked solar cells. The final calibrated image presents a high-quality and low-noise structure, thus making it easier to identify the micro crack size, location, and its orientation. In order to examine the effectiveness of the proposed technique, three different cracked photovoltaic (PV) solar cells have been examined. The results show that the micro cracks’ size, orientation, and location are 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.