Analysis of structural deformation-induced sun tracking error in a 5-kW high concentrator photovoltaic system

The purpose of this study is using finite element analysis (FEA) to investigate the effects of gravity and wind loads on the structural deformation and concentrator misalignment in a 5-kW high concentrator photovoltaic (HCPV) system. Several operation conditions, including no wind and wind speeds of 7 and 12 m/s blowing to the front side and back side of concentrator arrays, were applied to simulate the stress distribution and structural deformation in the given solar tracker. The concentrator misalignment caused by the structural deformation was also 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 the components in the given solar tracker under the loading conditions of gravity alone and plus a wind speed of 7 or 12 m/s according to the von Mises failure criterion. An agreement in the trend of variation of misalignment and resultant displacement of Fresnel lens in each concentrator was found. Therefore, the concentrator with a greater misalignment could be readily identified from the corresponding displacement distribution. Given the conditions of no wind and wind speeds of 7 and 12 m/s, the maximum concentrator misalignment was of 0.3° for a wind speed of 12 m/s blowing to the front side of concentrator arrays and it was within the range of an acceptance angle of 0.4° for the given concentrator.