METHODS OF MEASURING AND EVALUATING POWER LOSSES IN SOLAR CELL, SOLAR MODULE, AND SOLAR FACILITIES BY MEANS OF PHOTOGRAPHIC LUMINESCENCE AND THERMOGRAPHY MEASUREMENTS

摘要

The invention relates to a method for controlling the quality of a solar cell with the following steps:a first voltage (V 1) less than or equal to zero is applied to a solar cell and the emitted light of the solar cell is photographed so as to obtain a first image;a second voltage (V 2,) greater than zero is applied to the solar cell and the emitted light of the solar cell is photographed in order to obtain a second image;a third voltage (V 3) greater than zero and less than the second voltage is applied to the solar cell and the emitted light of the solar cell is photographed to obtain a third image;a fourth voltage (V 4) greater than the second and / or third voltage is applied to the solar cell and the emitted light of the solar cell is photographed so as to obtain a fourth image;either a first difference (D1) is formed between the pixel values of the photographs at the first and second voltages;a second difference (D2) is formed between the images for the third and fourth voltage;- The quotient between the first and the second difference is formed.- or the voltage V2 corresponds to the point of maximum power draw,and the image belonging to the first voltage (V 1) is subtracted pixel by pixel from the image to the second voltage (V 2) to obtain a first difference image (D1);the mean value M of all pixels of this difference image is formed;the image is subtracted pixel by pixel to the third voltage (V 3) from the image to the fourth voltage (V 4) to obtain a second differential image (D2);the values of the second difference image are divided by the determined mean value so as to obtain an image which quantitatively represents the inhomogeneity of the power dissipation.Instead of the luminescence images, thermographic images are taken at voltages V 3 and V 4 and a differential image is formed.