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Publications/Abstracts MFG

Abstracts of MFG Publications

Abstract: With today’s PV markets bogged down by the shortage of solar grade silicon a handful of start-ups but also well established manufacturers, try to take advantage of the situation and steadily stride towards the commercialisation of photovoltaic concentration technologies. To aid the completion of their ongoing development cycles, and implement production automation and quality control processes, specific instrumentation and machinery is to be developed. Assessment of sun tracking accuracy should not be overlooked, and even more by those players raising very high concentration concepts over the 100X frontier. Some analyses point out that the acceptance angle of present designs in concentration optics may be overestimated even from a theoretical point of view, which added to the still uncertain acceptance angle losses inflicted on the overall system by mass assembly processes, may finally shrink the allowable tolerance and divert the entire burden to the tracking accuracy. Instrumentation for the monitoring of sun tracking operative performance, providing enough sensitivity to gauge the sub-degree accuracy ranges required by high concentration systems is therefore needed, and technical feasibility of this proposal is proven here based in state-of-the-art solid state image sensors.

Abstract: With today’s PV markets bogged down by the shortage of solar grade silicon a handful of start-ups but also well established manufacturers, try to take advantage of the situation and steadily stride towards the commercialisation of photovoltaic concentration technologies. To aid the completion of their ongoing development cycles, and implement production automation and quality control processes, specific instrumentation and machinery is to be developed. Assessment of sun tracking accuracy should not be overlooked, and even more by those players raising very high concentration concepts over the 100X frontier. Some analyses point out that the acceptance angle of present designs in concentration optics may be overestimated even from a theoretical point of view, which added to the still uncertain acceptance angle losses inflicted on the overall system by mass assembly processes, may finally shrink the allowable tolerance and divert the entire burden to the tracking accuracy. Instrumentation for the monitoring of sun tracking operative performance, providing enough sensitivity to gauge the sub-degree accuracy ranges required by high concentration systems is therefore needed, and technical feasibility of this proposal is proven here based in state-of-the-art solid state image sensors.

Abstract: Nowadays CPV trends mostly based in lens parqueted flat modules, enable the separate design of the sun tracker. To enable this possibility a set of specifications is to be prescribed for the tracker design team, which take into account fundamental requisites such as the maximum service loads both permanent and variable, the sun tracking accuracy and the tracker structural stiffness required to maintain the CPV array acceptance angle loss below a certain threshold. In its first part this paper outlines the author’s approach to confront these issues. Next, a method is introduced to estimate the acceptance angle losses due to the tracker’s structural flexure, which in last instance relies in the computation of the minimum enclosing circle of a set of points in the plane. This method is also useful to simulate the drifts in the tracker’s pointing vector due to structural deformation as a function of the aperture orientation angle. Results of this method when applied to the design of a two axis CPV pedestal tracker are presented.

Abstract: A sun tracking error correcting routine, following the principles of classical controllers, is presented for integration in hybrid sun tracking strategies working on an open loop sun ephemeris basis, which is to be subsequently adjusted. Space scanning routines for feedback acquisition and tabulation of error estimates are introduced to complete the strategy. First analysis of the behavior of this strategy is obtained through customdeveloped simulation software. In this context EUCLIDES concentrator error correcting routine is reviewed, and its comparison with the PI strategy gives way for extrapolation to a more general framework for hybrid strategies, which opens a range of different possibilities.
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