1,221 research outputs found
The ERDA/LeRC photovoltaic systems test facility
A test facility was designed, and built to provide a place where photovoltaic systems may be assembled and electrically configured, to evaluate system performance and characteristics. The facility consists of a solar cell array of an initial 10-kW peak power rating, test hardware for several alternate methods of power conditioning, a variety of loads, an electrical energy storage system, and an instrumentation and data acquisition system
Method of making encapsulated solar cell modules
Electrical connections to solar cells in a module are made at the same time the cells are encapsulated for protection. The encapsulating material is embossed to facilitate the positioning of the cells during assembly
Decision-Feedback Detection Strategy for Nonlinear Frequency-Division Multiplexing
By exploiting a causality property of the nonlinear Fourier transform, a
novel decision-feedback detection strategy for nonlinear frequency-division
multiplexing (NFDM) systems is introduced. The performance of the proposed
strategy is investigated both by simulations and by theoretical bounds and
approximations, showing that it achieves a considerable performance improvement
compared to previously adopted techniques in terms of Q-factor. The obtained
improvement demonstrates that, by tailoring the detection strategy to the
peculiar properties of the nonlinear Fourier transform, it is possible to boost
the performance of NFDM systems and overcome current limitations imposed by the
use of more conventional detection techniques suitable for the linear regime
Why Noise and Dispersion may Seriously Hamper Nonlinear Frequency-Division Multiplexing
The performance of optical fiber systems based on nonlinear
frequency-division multiplexing (NFDM) or on more conventional transmission
techniques is compared through numerical simulations. Some critical issues
affecting NFDM systems-namely, the strict requirements needed to avoid burst
interaction due to signal dispersion and the unfavorable dependence of
performance on burst length-are investigated, highlighting their potentially
disruptive effect in terms of spectral efficiency. Two digital processing
techniques are finally proposed to halve the guard time between NFDM symbol
bursts and reduce the size of the processing window at the receiver, increasing
spectral efficiency and reducing computational complexity.Comment: The manuscript has been submitted to Photonics Technology Letters for
publicatio
Preliminary results of accelerated exposure testing of solar cell system components
Plastic samples and solar cell sub modules were exposed to an accelerated outdoor environment in Arizona and an accelerated simulated environment in a cyclic ultraviolet exposure tester which included humidity exposure. These tests were for preliminary screening of materials suitable for use in the manufacture of solar cell modules which are to have a 20-year lifetime. The samples were exposed for various times up to six months, equivalent to a real time exposure of four years. Suitable materials were found to be FEP-A, FEP-C, PFA, acrylic, silicone compounds and adhesives and possibly parylene. The method of packaging the sub modules was also found to be important to their performance
A Novel Detection Strategy for Nonlinear Frequency-Division Multiplexing
A novel decision feedback detection strategy exploiting a causality property
of the nonlinear Fourier transform is introduced. The novel strategy achieves a
considerable performance improvement compared to previously adopted strategies
in terms of Q-factor.Comment: The work has been submitted to the Optical Fiber Communication (OFC)
Conference 201
DOE LeRC photovoltaic systems test facility
The facility was designed and built and is being operated as a national facility to serve the needs of the entire DOE National Photovoltaic Program. The object of the facility is to provide a place where photovoltaic systems may be assembled and electrically configured, without specific physical configuration, for operation and testing to evaluate their performance and characteristics. The facility as a breadboard system allows investigation of operational characteristics and checkout of components, subsystems and systems before they are mounted in field experiments or demonstrations. The facility as currently configured consist of 10 kW of solar arrays built from modules, two inverter test stations, a battery storage system, interface with local load and the utility grid, and instrumentation and control necessary to make a flexible operating facility. Expansion to 30 kW is planned for 1978. Test results and operating experience are summaried to show the variety of work that can be done with this facility
Real time outdoor exposure testing of solar cell modules and component materials
Plastic samples, solar cell modules, and sub-modules were exposed at test sites in Florida, Arizona, Puerto Rico, and Cleveland, Ohio, in order to determine materials suitable for use in solar cell modules with a proposed 20-year lifetime. Various environments were encountered including subtropical, subtropical with a sea air atmosphere, desert, rain forest, normal urban, and urban-polluted. The samples were exposed for periods up to six months. Materials found not suitable were polyurethane, polyester, Kapton, Mylar, and UV-stabilized Lexan. Suitable materials were acrylic, FEP-A, and glass. The results of exposure of polyvinylidene fluoride were dependent on the specific formulation, but several types appear suitable. RTV silicone rubber (clear) appears to pick up and hold dirt both as a free film and as a potting medium for modules. The results indicate that dirt accumulation and cleanability are important factors in the selection of solar cell module covers and encapsulants
Terrestrial applications of FEP-encapsulated solar cell modules
FEP-encapsulated solar cell modules and arrays have been designed and built expressly for terrestrial applications. System design including solar cell array mechanical design and the approach to system sizing is outlined. Such solar cell systems have been installed at six sites. Individual modules have undergone marine environment tests. Results from seven months of operation indicate that system is meeting its electrical design requirements. No mechanical degradation has been reported. The array on Mammoth Mountain, California has been damaged by rime ice but shows no loss in electrical output. Marine environment tests on single modules have shown that elements of the module must be completely sealed by the FEP. Based on the limited test data available, the FEP-encapsulated solar cell module appears well suited to terrestrial applications
Status of FEP encapsulated solar cell modules used in terrestrial applications
The Lewis Research Center has been engaged in transferring the FEP encapsulated solar cell technology developed for the space program to terrestrial applications. FEP encapsulated solar cell modules and arrays were designed and built expressly for terrestrial applications. Solar cell power systems were installed at three different land sites, while individual modules are undergoing marine environment tests. Four additional power systems are being completed for installation during the summer of 1974. These tests have revealed some minor problems which have been corrected. The results confirm the inherent utility of FEP encapsulated terrestrial solar cell systems
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