Anchor Points Based Accurate Fault Locating in Large-Scale Photovoltaic Plants via Aerial Infrared Videos
Yuxiang Ying, Yuhua Qi, Liming Rong, Hong Men, Young Hoon Joo
Abstract
For large-scale photovoltaic plants, accurate fault locating provides strong support for efficient maintenance. Based on aerial infrared videos, a progressive locating method is proposed to locate faults in the photovoltaic plants. The photovoltaic string is first located, and the faults are located on the modules of the corresponding photovoltaic string. For the former, the image extracted from the infrared video is binarized in HSV color space, and then the target pixels are horizontally and vertically projected to realize photovoltaic string segmentation and locating. For the latter, the faults are first located in the local coordinate system of each frames and then located in the overall coordinate system of the video by conversion. The conversion is realized by the matching of the anchor points in adjacent frames. The anchor points are detected by AKAZE algorithm and the matching is achieved by Lucas–Kanade sparse optical flow algorithm. The overall coordinate expression of the fault is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$(R, C, (x, y))$</tex-math></inline-formula> that consists of the row index number <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</i> of the photovoltaic string in the photovoltaic plant, the column index number <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$C$</tex-math></inline-formula> of the photovoltaic string in the current row <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$R$</tex-math></inline-formula> , and the faulty module location <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$(x, y)$</tex-math></inline-formula> on the photovoltaic string. Infrared videos of a 30-MW photovoltaic plant are tested, and the average accuracy of locating was 97.5%. Compared with nonprogressive locating method, the average accuracy of locating is higher by 17.5%. It can be seen that the proposed progressive locating method can accurately locate faults in large-scale photovoltaic plants.