1,721,122 research outputs found
A hardware field simulator for photovoltaic materials applications.
No full textThis work is on a photovoltaic field simulator that is a power electronic device which produces direct voltages and currents. These simulate the behaviour of a photovoltaic field working in arbitrary conditions of solar irradiance and temperature. The most important application of the simulator is the testing of inverters. This work also introduces a new model describing the behaviour of photovoltaic modules of any generation. This is particularly useful to scientists and plant designers as it is based only on the electrical parameters that are always reported in a photovoltaic module’s datasheet
Non-destructive vibration-based monitoring analysis of PV modules with encapsulant degradation by frequency change
Full text linkIn engineering applications, the frequency analysis represents a first and practical step to collect relevant parameters for structural and mechanical diagnostics. Any possible material / component degradation and deterioration can be prematurely detected by frequency modifications that exceed a certain alert value. In this paper, the attention is given to the dynamic mechanical analysis of commercial photovoltaic (PV) modules, in which the solar cells are typically encapsulated in thin viscoelastic interlayers made of Ethylene-Vinyl Acetate (EVA), which are primarily responsible for the load-bearing capacity of the sandwich PV system. As a major effect of ageing, ambient conditions, non-uniform / cyclic thermal gradients, humidity and even extreme mechanical / thermal loads, the rigidity of these films can largely modify and decrease, thus possibly affecting the mechanical capacity of the PV module, and even exposing the solar cells to fault. Knowledge of the effective bonding level is an important step for diagnostic purposes. In this regard, the present study is based on a preliminary non-destructive experimental analysis, and on an extensive parametric Finite Element (FE) numerical investigation of full-scale commercial PV modules of typical use in buildings. The attention is given – for PV module arrangements of technical interest – to the effect of EVA stiffness in terms of vibration modes and frequency sensitivity. As shown, especially compared to newly installed PV modules, any kind of stiffness decrease is associated to major frequency modifications for the composite system, and in the worst configuration, such a frequency scatter can decrease down to −40% the original condition. Such a marked stiffness decrease would be implicitly associated to a weak mechanical performance of the sandwich section, with major stress peaks and deflections in the PV system, even under ordinary loads. The presented results, in this sense, suggest that major consequences can be prevented and minimized by monitoring the vibration frequency of PV modules
A 24-hours forecast of solar irradiance using artificial neuralnetwork: Application for performance prediction of a grid-connected PV plant at Trieste,Italy
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