Search results for "Volt"
showing 10 items of 2187 documents
The use of results of spectral analysis of synchronous generator output voltage for technical diagnostics.
2006
The method of technical diagnostics of ship diesel engine-generator installations is offered. Spectral-power diagnostic parameters of the synchronous generator voltage and currents are used. The electric machine in this case is the multipurpose sensor of diagnostic parameters. On these parameters it is possible to judge quality of course of working processes in diesel engine cylinder, its technical condition. This method is applicable to piston compressor installations with the electric drive.
A Contribution to Tests Standardization for Inverter-Fed Asynchronous Machines
1986
Losses of inverter-fed asynchronous motors and their experimental evaluation are considered. The formal expressions of iron and copper losses are first recalled, and it is shown as they are influenced by the harmonic content of inverter output voltages. Theoretical and experimental values of these losses are then given together with the presentation of the experimental tests used for their determination. A suitable set of tests is then suggested for the determination of the conventional efficiency of inverter-fed asynchronous motors. The content cannot be considered exhaustive on the matter. It represents only a first contributive approach to the standardization of inverter-fed asynchronous…
Econo- Environmental Dispatch Solutions for Power Systems Integrated with Renewable Energy Resources
2020
Due to the global initiatives for sustainable energy supply, the electric grids are increasingly integrated with environment-friendly and renewable energy resources. Hence, the power dispatch strategies are to be timely modified by incorporating the environmental aspects of generation along with the economic considerations. In this paper, we propose such an Econo- Environmental dispatch (EED) system for a power grids, which are integrated with renewable energy sources. The EED problem is formulated with two objective functions which aims at minimizing the unit cost of generation as well as minimizing the emissions caused during the power production. For attaining these objectives, cost and …
PV Reconfiguration Systems: a Technical and Economic Study
2017
Dynamical electrical array reconfiguration strategies for grid-connected PV systems have been proposed as solution to improve energy production due to the mismatch effect of PV plants during partial shading conditions. Strategies are based on the use of dynamic connections between PV panels given by the employment of switches that allow for each panel the series, parallel or exclusion connections, physically changing the electrical connections between the related PV modules, consequentially modifying the layout of the plant. Usually the cost of the dynamic matrix is not taken into account. This novel work evaluates the economic advantages obtained by the use of reconfiguration strategies in…
New European Wind Atlas: Mesoscale Atlas
2021
The mesoscale part of the New European Wind Atlas (NEWA) was created from WRF model simulations for all of Europe at a grid spacing of 3 km x 3 km, initially covering the 30 years from 1989 to 2018. The WRF model simulations (using WRF V3.8.1) were done in 10 partly overlapping domains using ERA5 reanalysis and OSTIA sea surface temperatures. We used many ensemble members to determine the most suitable configuration for the final production run. The model configuration, production and evaluation of the results against observations are described in Hahmann et al. (2020) and Dörenkämper et al. (2020).Data are accessible through doWIND, an instance of daTap (RESTfull API for data aggregation a…
Machine-learned models for the performance of six different solar PV technologies under the tropical environment
2020
Due to the recent environmental concerns and long-term challenges in energy security, the Global energy scenarios are shifting more towards sustainable and renewable energy resources. Brunei has planned to increase the use of cleaner energy technologies by contributing 10 percent or 954 GWh of renewable energy in its power generation mix by 2035. Out of the available renewable options, solar is the most promising one for Brunei, for example, the daily average solar installation is around 5kWh per day [1]. Though solar energy is an abundant resource, for optimally designing and successfully managing solar power projects, its availability in different time scales are to be analyzed and unders…
Impact of pulsed electric fields and high voltage electrical discharges on extraction of high-added value compounds from papaya peels
2014
Abstract Extraction of the nutritionally valuable and antioxidant compounds from papaya peels using conventional aqueous extraction (E) (at 20 °C, 50 °C, and 60 °C) and extraction assisted by pulsed electric field (PEF) or by high voltage electrical discharges (HVED) was studied. Increase of extraction temperature or extraction in basic media (pH = 11) not always resulted in an increase of the yields or TEAC values. E.g., the concentration of proteins and TEAC values at pH = 7 and pH = 11 were noticeably smaller at 60 °C as compared to those measured at 50 °C. HVED-assisted technique showed a higher extraction efficiency of high-added value compounds compared to PEF-assisted extraction. E.g…
A comparative evaluation of palladium and platinum nanoparticles as catalysts in proton exchange membrane electrochemical cells
2008
The goal of the present study is the development and comparative characterisation of carbon-supported and nanostructured Pd- and Pt-based electrocatalysts for hydrogen oxidation in Proton Exchange Membrane (PEM) H2/O2(air) fuel cells and proton reduction in PEM water electrolysers. Catalysts have been synthesised in a solution using a combined impregnation/reduction polyol method. They have been characterised using X-ray Diffraction (XRD) analysis, Transmission Electron Microscopy (TEM), Thermogravimetric Analysis (TGA) and cyclic voltammetry. NanoPt, nanoPd and nanoPt-Pd catalysts deposited onto a carbon carrier have been used to prepare Membrane-Electrode Assemblies (MEAs) which, in turn,…
Experimental analysis of materials in proton exchange membrane electrolysis cells
2019
Abstract An accelerated supply and demand of energy has resulted in an increased need for efficient energy storage options, where storing energy in hydrogen gas emerges as one of the most attractive. In this study, a singular proton exchange membrane (PEM) electrolysis cell was designed using adequately low-cost materials, and tested using polarisation curves, cyclic voltammetry and AC impedance. A comparative study of various micro porous layer (MPL) materials was performed in an effort to find suitable options which are able to steadily operate under anodic conditions. The best performance was achieved using carbon cloth, however this material was unstable. Untreated porous titanium and n…
Design of a LLC Resonant Converter for Powering a PEM Electrolyzer
2021
International audience; This paper proposes the design of a LLC resonant converter to supply a proton exchange membrane (PEM) electrolyzer. The PEM requires a low voltage with high current, a reduced output voltage ripple, and an overdamped dynamic behavior of the converter to avoid voltage overshoots. The designed converter allows satisfying the design constraints, minimizing switching and reverse recovery losses; the efficiency is influenced mainly by the output rectifier's conduction losses.