Experimental investigation on wind-induced vibration of photovoltaic modules supported by suspension cables

Abstract

Under the background of the global energy crisis and excessive carbon emissions, solar power stations have increased rapidly in number and size in recent years. To satisfy the construction needs on complex or special sites (e.g. intertidal zone, mountainous area, fishponds, etc.), a suspension cable supported photovoltaic (PV) module was developed recently and quickly aroused market interest; however, such cable-supported flexible PV systems are susceptible to wind loading and associated aerodynamic effects thereon remain unclear. Therefore, both aeroelastic and rigid model wind tunnel tests were conducted to investigate the wind-induced vibration (WIV) characteristics of a typical cable-supported PV module. The effects of module tilt angle, cable pre-tension, and wind speed on the vertical displacement response and the aerodynamic damping were evaluated. Based on wind pressure tests and finite element simulation, the three-dimensional WIV behavior of PV modules could be investigated. The non-dimensional gust loading factor representing the load dynamic amplification was presented based on multi-target equivalent static wind loads. Results show that wind-induced vertical vibration of the PV modules increased with tilt angle but reduced with increasing cable pretension. The fluctuating displacement shows a quasi-linear increase with the square of the wind speed. Negative aerodynamic damping was found for a tilt angle of 10° under high wind speeds. Compared to vertical vibration, horizontal and torsional responses were insignificant for the tested PV modules. The estimated gust loading factor for the PV module with tilt angle of 10° was between 1.1 and 2.5.