Wind-Induced Vibration Characteristics and Aerodynamic Coupling Mechanisms of Large-Span Flexible Photovoltaic Systems: Insights from Aeroelastic Wind Tunnel Tests

Flexible photovoltaic (PV) systems are highly sensitive to multi-directional wind disturbances, particularly in complex terrain environments, resulting in intricate and less predictable wind-induced vibration (WIV) behavior. This study experimentally investigates the vertical and torsional vibration characteristics of a single-row, large-span flexible PV system under 0°-180° wind direction angles using aeroelastic wind tunnel testing. Specifically, the experiments systematically explored the effects of installation inclination, wind direction, and incoming flow velocity on the system’s vibration response. The results indicate that the WIV response exhibits strong multi-parameter coupling, with abrupt amplitude jumps occurring at critical wind speeds of 6-8 m/s. Distinct differences exist between modules, i.e., central module experiences pronounced vibration, whereas edge module remains comparatively stable. Torsional vibration correlation consistently exceeds vertical correlation, and the system exhibits same-frequency resonance, with resonance frequencies strongly modulated by wind direction. These findings establish a quantitative framework for understanding the multi-parameter coupling dynamics of flexible PV systems and provide an experimental basis for improving their wind-resistant design and aeroelastic stability under complex environmental conditions.