The Development of the I-V Measurement by Pulsed Multi-Flash, and the Effectiveness
In order for the device to measure the I-V characteristics of the photovoltaic (PV) module to be used in the PV module assembly line, easy handling of the module, improvement of measurement accuracy, and reduction of the measuring time are strongly requested. We developed the solar simulator with several milliseconds flat pulsed light of multi flashes and accomplished the improvement of measurement accuracy, and the reduction of the measuring time. Both I-V measuring device and measuring method we developed are also effective in estimating the characteristics of response, light induced change, and being newly developed PV modules
Discussion of a Failure Hot-Spot Endurance Testing Case for CIGS Thin-Film Photovoltaic Module
This paper describes the use of steady-state solar simulator for CIGS thin-film photovoltaic module hot-spot endurance test. In the study, not only are test procedures of hot-spot endurance test in IEC 61646 discussed, but also how to evaluate the performance of steady-state solar simulator by IEC 60904-9 is presented. Three CIGS thin-film PV modules with the same types are used for hot-spot endurance test in case study. It is found that some of the cell damages and visual defects on tested PV modules are clearly observed.
Effect of stress conditions on collapse deformation behavior of a rockfill material
A set of saturated and dry-saturated large-scale triaxial tests were conducted in order to explore the effects of stress conditions on the saturation-induced collapse deformation behavior of a rockfill material. Specimens were tested in different confining pressures and for dry-saturated tests the specimens were submerged in various shear stress levels. The results indicate that in all of the dry-saturated tests a sudden reduction in the volume of the specimens was observed during the submerging process. The ratio of the minimum axial strength of a submerged specimen (at the end of the saturation process) to the shear strength of the specimen before saturation is defined as the coefficient of stress recovery, Csr. Results of the dry-saturated tests showed that this ratio increases as the confining pressure increases and decreases by increasing the shear stress level. According to the results of dry-saturated tests the values of internal friction angle reduction caused by saturation (Δϕc), the ratio of the elasticity modulus of the material after saturation to its elasticity modulus in dry condition, i.e., Ewet/Edry, and also the saturation induced sudden volumetric strain (εvc) decrease as the confining pressure increases. However the shear stress level does not have any meaningful effect on the variation of Dfc, Ewet/Edry and (εvc).