Informatics Publishing Limited

S. Vijayalekshmy ¹, G. R. Bindu ¹, S. Rama Iyer ²

Affiliations
1 Department of Electrical and Electronics, College of Engineering, Trivandrum, Thiruvananthapuram - 695016, Kerala, IN
2 Department of Electrical and Electronics, College of Engineering, Trivandrum, Thiruvananthapuram - 695016, Ker, IN

Abstract

Background/Objectives: Clouds cause spatial and unevenness of solar radiation falling on Photovoltaic (PV) array which leads to unpredictable PV power fed into the grid. Power loss depends on the shading pattern. Methods/ Statistical Analysis: This paper reveals comparative analyses on the improvement in power of various photovoltaic array configurations by shifting the placement of various panels in the array, under passing cloud conditions. The location of the modules is altered on account of the “Su Do Ku” pattern so that there is scattering of shading throughout the array. This reduces the multiple local maxima in Power-Voltage (P-V) array characteristics of PV array. Findings: The reallocation of the Photovoltaic modules within the array according to the mentioned puzzle pattern is found to decrease the power losses due to partial shading and also improves the nominal voltage of the array. This reduces the multiple local maxima in Power-Voltage (P-V) array characteristics and improves the nominal voltage of PV array. Hence, the tracing of Global Maximum Power Point (GMPP) in the present method is simpler. The mentioned method of rearrangement has been found to increase the power output for total cross tied configuration under static illumination conditions. The improvement in power output of the array is examined for five different configurations here under changing illumination conditions and the consequences show there is increase of power output for considered four configurations under this scheme of arrangement. Conclusion/Improvements: The present work can be extended for determining an optimal reallocation scheme for maximising the power output under partial shading conditions.

Keywords

Array Configuration, Bypass Diode, Changing Illumination, Fill Factor, Shade Dispersion, Shading Loss

Full Text

   

K. Sabeena Beevi ¹, G. R. Bindu ¹

Affiliations
1 Department of Electrical Engineering, College of Engineering Trivandrum, Thiruvananthapuram - 695016,Kerala, IN

Abstract

This paper proposes a unique detection technique to identify nuclei from microscopy images of breast histopathology slides. The method involves stain normalization, color decomposition and hysteresis thresholding. A comparative analysis of different pre-processed images on nuclei detection reveals an accuracy of 97% for Blue Ratio (BR) images. The technique uses three color channels for accurate detection of nuclei. An analysis of two stain normalization procedure is also presented.

Keywords

Blue Ratio Image, Histopathology, Stain Normalization

Full Text