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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
concentratormisalignment in a 5-kW high concentrated photovoltaic (HCPV)
system. Several operation conditions, including no wind and wind
speeds of 7, 12, and 37.5 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. An estimation of fatigue life was made for the given
solar tracker under cyclic operation. 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
theconstructed FEA model was validated to be effective in assessment
of the structuralintegrity 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. However, the von Mises equivalent stress in some
components of the given solar tracker was larger than the yield
stress at some zenith angles for a wind speed of 37.5 m/s such that
a structural failure (plastic deformation) was predicted. 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 0.3o 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 0.4o
for the given concentrator. An estimation of fatigue life for the
given solar tracker is 5.8 × 1010 days under a wind speed
of 12 m/s. In this regard, no fatigue failure was predicted for the
given solar tracker under a normally cyclic operation condition.
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