Analysis of Structural Deformation and Concentrator Misalignment in a 1-kW Solar Tracker

• Main Authors: June-Yuan Fang, 方君元
• Other Authors: Chih-Kuang Lin
• Format: Others
• Language: en_US
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/53503053977120652288

碩士 === 國立中央大學 === 機械工程研究所 === 99 === The purpose of this study is to investigate the effects of gravity and wind loadings on structural deformation and concentrator misalignment in a 1-kW high concentrator photovoltaic (HCPV) system using finite element analysis (FEA) approach. A three-dimensional (3-D) FEA model was constructed for a roll-tilt form of solar tracker in an HCPV system developed at the National Central University. Several loading conditions, including gravity only and gravity plus wind speeds of 7 and 12 m/s blowing toward the front (wind direction of 0o), lateral (wind direction of 90o), and rear (wind direction of 180o) sides of the solar tracker, were applied to calculate the stress distribution and structural deformation. Three changeable tilt angles of 24.5o (the spring/autumn equinox), 1o (the summer solstice), and 48o (the winter solstice) for the concentrator modules were also taken into account. Meanwhile, the concentrator misalignment induced by the structural deformation was calculated. A comparison of the simulation and measurement results of strain change at two selected locations in the given solar tracker during field operation was made to validate the constructed FEA model. A reasonable agreement of the simulation and measurement results was found such that the constructed FEA model was validated to be effective in assessment of the structural integrity of an HCPV system. No structural failure was predicted for all components in the given solar tracker under all the given loading conditions according to von Mises failure criterion. An agreement in the trend of variation of concentrator misalignment and normal displacement of Fresnel lens in each concentrator module was found. Therefore, the concentrator with a greater misalignment could be readily identified from the corresponding normal displacement distribution. For all the cases investigated, the maximum concentrator misalignment was of 0.142o for a wind speed of 12 m/s with wind direction of 90o for the tilt angle of 1o (the summer solstice) and it was within the range of an acceptance angle of 0.5o for the given concentrator module. Consequently, the given HCPV system can operate safely under the effects of wind speeds of 7 and 12 m/s with a good efficiency in power generation.