Extreme Value Analysis of Wind Loads on an Adjustable-Tilt Solar Photovoltaic System: A Wind Tunnel Force Measurement Experiment

This study presents wind tunnel experiments on an adjustable-tilt solar photovoltaic (PV) system, covering wind directions from 0° to 180° and tilt angles from 5° to 60°, with time histories of column base shear force recorded under 65 working conditions. The Gaussianity of the shear force time histories is assessed using skewness (Csk) in the range of −0.15 to 0.15 and kurtosis (Cku) greater than 3.2, which explicitly indicates a non-Gaussian distribution. Results show that base shear forces tend to follow a Gaussian distribution at lower tilt angles, while higher angles lead to non-Gaussian behavior due to organized vortex shedding. Three extreme value analysis methods are compared, with the generalized Pareto distribution (GPD) method demonstrating the highest accuracy and the smallest estimation deviation. The GPD-based maximum shear forces not only align closely with observed values but also satisfy structural wind resistance requirements. Compared with average values, the extreme shear force generally shows higher magnitudes under the same conditions. These findings highlight the importance of accounting for extreme loading effects in structural design and offer practical guidance for the wind-resistant design of adjustable-tilt PV systems.