| 1. |
- Fernandes, C. A. F., et al.
(författare)
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Stationary solar concentrating photovoltaic-thermal collector - Cell string layout
- 2016
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Ingår i: Proceedings - 2016 IEEE International Power Electronics and Motion Control Conference, PEMC 2016. - : IEEE. - 9781509017980 ; , s. 1275-1282
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Konferensbidrag (refereegranskat)abstract
- The aim of this work is to design the cell string layout in stationary concentrating photovoltaic (PV) or hybrid systems (PVT) in order to minimize the effects of both the longitudinal and transversal shading inherent to concentrating collectors. In this paper it is determined the best configuration of a PV string of cells, composed by several modules, by using a simple mathematical model based on the current vs. voltage of the PV cell. The model calculates the power vs. voltage curves of different possible configurations, in order to identify the optimal one according to efficiency and reliability. The company SOLARUS manufactures PVT collectors with cell strings of 38 solar cells connected in series. Solar cells in the concentrated side of the collector are shaded due to the presence of the aluminium frame of the PVT collector. The effects of shading and non-uniform illumination are minimized by including bypass diodes. Each string has 4 modules of bridged cells, each one associated to a bypass diode. In this work, different combinations of string cells in the collector receiver have been simulated using the free circuit simulation package from Linear Technology Corporation (LTSPICE). Test results are provided by SOLARUS to validate the proposed approach. A comparative analysis is presented at the end, showing that the simulation model is an important tool to define the module configurations that achieve the best energy efficiencies of the PVT panel.
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| 2. |
- Gomes, João, et al.
(författare)
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Analysis of different C-PVT reflector geometries
- 2016
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Ingår i: Proceedings - 2016 IEEE International Power Electronics and Motion Control Conference, PEMC 2016. - : IEEE. ; , s. 1248-1255
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Konferensbidrag (refereegranskat)abstract
- One of the main advantages of solar concentrating photovoltaic-thermal collectors (C-PVT) is that these systems are all-in-one module type. For this reason, they are associated to less area and material requirements. Nevertheless, these systems require a more complex analysis in order to improve their performances, since the two types of energy conversion are related to the different demands and their cross effects. In the overall analysis, the collector geometry and the used materials for all their components will be crucial to ensure the system reliability. This study presents preliminary work about re-designing the reflector of C-PVT collectors currently produced in the Swedish SME Solarus Sunpower AB with a comparative analysis on an annual basis of the solar radiation that reaches the collector. For the work accomplished, an open-source advanced object-oriented Monte Carlo ray tracing program (Tonatiuh) is used. For low latitudes, two reflector shapes have been selected since they ensure better performances than the current Solarus reflector. These two new designs achieve both the performance and cost-effectiveness objectives: for the same aperture area and for a thinner box, the collector is 7% to 10% more effective and 18% cheaper.
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| 3. |
- Torres, João Paulo N., et al.
(författare)
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The effect of shading on photovoltaic solar panels
- 2018
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Ingår i: Energy Systems, Springer Verlag. - : Springer Berlin/Heidelberg. - 1868-3967 .- 1868-3975. ; 9:1, s. 195-208
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Tidskriftsartikel (refereegranskat)abstract
- A modelling description of photovoltaic (PV) modules in a PSPICE environment is presented. To validate the simulation model, a lab prototype is used to create similar conditions as those existing in real photovoltaic systems. The effects of partial shading of solar cell strings and temperature on the performance of various PV modules are analyzed. The simulation results show a very good agreement with those obtained experimentally in similar conditions, either in lab, at Lisbon University, and under outdoor testing in Sweden, using PV solar collectors manufactured by Solarus Sunpower AB. The potential of the simulation analysis is highlighted as a flexible and powerful tool for the design of new and more competitive PV module configurations for the collectors in solar panels.
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