Structural analysis of a tracking photovoltaic system with a pedestal solar tracker

The structural integrity and deformation-induced misalignment of solar radiation for a tracking photovoltaic (PV) system under self-weight is investigated using a finite element analysis (FEA) approach. Gravity is applied to calculate the stress distribution and structural deformation. Misalignment of solar radiation induced by structural deformation is also calculated. Moreover, to avoid damages caused by resonance, natural frequencies of vibration for the given tracking PV system are also determined. Strain changes are measured experimentally at two selected locations in the given solar tracker during field operation for comparison with the simulation results. A reasonable agreement between the simulations and experimental measurements is found such that the constructed FEA model is validated to be effective in assessment of the structural integrity for PV systems under self-weight. No structural failure is predicted for all components in the given solar tracker under the given loading condition according to the von Mises failure criterion. An agreement in the trend of variation of misalignment and resultant displacement of PV modules is found. Considering the effect of self-weight only, the maximum misalignment of solar radiation is of 0.275° at elevation angle of 45° when rotating the solar tracker from 0° to 75°. It is expected that such a misalignment value will not cause a significant degradation of power generation for a PV system. The range of natural frequencies of the first six vibration modes for the given PV system is from 3.85 Hz to 11.4 Hz.