颗粒群冲击诱导光伏电池性能衰减的特性与机理OACSTPCD

Photovoltaic cells have been widely used in desert areas and other solar-rich environments due to the relatively high solar energy to electricity conversion efficiency.Under the long-term dust impact condition in the desert dust environment,the internal structures of photovoltaic cells are prone to damage,resulting in a significant deterioration of photoelectric conversion efficiency.Therefore,it is of great significance to understand the photoelectric response of photovoltaic cells subjected to massive particles impact.Firstly,a millimeter-scale high-speed particle impact experimental method was developed based on split Hopkinson pressure bar(SHPB)facility.The experimental results showed that the damage of the photovoltaic cell was mainly caused by the first impact,leading to the damage characteristics including shear microcracking,brittle fracture and delamination.Then,the critical stresses corresponding to the three failure modes were analyzed in terms of the initial impact kinetic energy.The first failure mode assumes that high-speed particles behave as fluids,so impulsive compressive stresses are used in the model.The damage in the second failure mode comes from high contact stresses on the impacted surface.The damage in the third mode of failure comes from bending stresses.The photovoltaic performance degradation of the photovoltaic cells after impact under different particle velocities,diameters,and number densities were investigated,showing that the photoelectric conversion efficiency of the photovoltaic cells decreased significantly with the increase of the particle size,the impact velocity,and the number density.Finally,a damage-induced photovoltaic performance degradation(DPPD)model under sand and gravel impact conditions is established to quantitatively describe the influence of impact parameters on the photovoltaic conversion efficiency,in which the two-dimensional damage factor D is proposed to represent the average damage level of the damaged area.The results of the DPPD model are in agreement with the experimental results,validating the applicability of the model for predicting accurately the photovoltaic cell photovoltaic performance under massive sand and gravel impact environment.