Wind Pressure Spectrum and Energy Distribution Characteristics of Long-Span PV Arrays Based on Wind Tunnel Tests

Long-span cable-supported photovoltaic (PV) arrays are prone to local damage or overall overturning under strong wind. Revealing the characteristics of wind pressure spectrum and energy distribution is a key challenge in their dynamic wind resistance research. Taking the 5 rows × 3 spans PV arrays of State Power Investment Group Cable-supported PV Demonstration Base in Yancheng, Jiangsu, China, as the research object, the spatial distribution and correlation of wind pressure on the top and lower surfaces of the PV arrays were analyzed based on wind tunnel tests of a rigid model. The energy distribution and coherence of wind pressure under the most unfavorable wind directions were revealed, and the spectrum models of wind pressure and resultant forces were established. Research has shown that under the most unfavorable wind directions of 0° and 180°, interference between rows enhances the fluctuating wind pressure at the middle of a span on the windward leading edge of the PV panel, transferring the energy of wind pressure from the low-frequency range to the high-frequency range. It also enhances the energy of lift/drag forces of the windward leading edge of the PV panel in the sensitive frequency range of structural dynamic effects, reduces the energy of torque of the PV panel, increases the bending deformation of the PV panel, and reduces its torsional deformation. The coherence of wind pressure between the upper and lower edges of the PV panels under wind direction of 0° is greater than that under wind direction of 180°. In the normalized frequency range [1, 5], interference between rows reduces the coherence of lift/drag forces between the upper and lower edges of the PV panels.