27,280 research outputs found
Data Acquisition and Control System of Hydroelectric Power Plant Using Internet Techniques
VodnĂ energie se nynĂ stala nejlepĆĄĂm zdrojem elektrickĂ© energie na zemi. VyrĂĄbĂ se pomocĂ energie poskytovanĂ© pohybem nebo pĂĄdem vody. Historie dokazuje, ĆŸe nĂĄklady na tuto elektrickou energii zĆŻstĂĄvajĂ konstantnĂ v prĆŻbÄhu celĂ©ho roku. Vzhledem k mnoha vĂœhodĂĄm, vÄtĆĄina zemĂ nynĂ vyuĆŸĂvĂĄ vodnĂ energie jako hlavnĂ zdroj pro vĂœrobu elektrickĂ© energie.NejdĆŻleĆŸitÄjĆĄĂ vĂœhodou je, ĆŸe vodnĂ energie je zelenĂĄ energie, coĆŸ znamenĂĄ, ĆŸe ĆŸĂĄdnĂ© vzduĆĄnĂ© nebo vodnĂ zneÄiĆĄĆ„ujĂcĂ lĂĄtky nejsou vyrĂĄbÄny, takĂ© ĆŸĂĄdnĂ© sklenĂkovĂ© plyny jako oxid uhliÄitĂœ nejsou vyrĂĄbÄny, coĆŸ ÄinĂ tento zdroj energie ĆĄetrnĂœ k ĆŸivotnĂmu prostĆedĂ. A tak brĂĄnĂ nebezpeÄĂ globĂĄlnĂho oteplovĂĄnĂ. PouĆŸitĂ internetovĂ© techniky k ovladĂĄnĂ nÄkolika vodnĂch elektrĂĄren mĂĄ velmi vĂœznamnĂ© vĂœhody, jako snĂĆŸenĂ provoznĂch nĂĄkladĆŻ a flexibilitu uspokojenĂ zmÄny poptĂĄvky po energii na stranÄ spotĆeby. TakĂ© velmi efektivnÄ ÄelĂ velkĂœm naruĆĄenĂm elektrickĂ© sĂtÄ, jako je napĆĂklad pĆidĂĄnĂ nebo odebrĂĄnĂ velkĂ© zĂĄtÄĆŸe, a poruch. Na druhou stranu, systĂ©m zĂskĂĄvĂĄnĂ dat poskytuje velmi uĆŸiteÄnĂ© informace pro typickĂ© i vÄdeckĂ© analĂœzy, jako jsou ekonomickĂ© nĂĄklady, predikce poruchy systĂ©mĆŻ, predikce poptĂĄvky, plĂĄny ĂșdrĆŸby, systĂ©mĆŻ pro podporu rozhodovĂĄnĂ a mnoho dalĆĄĂch vĂœhod. Tato prĂĄce popisuje vĆĄeobecnĂœ model, kterĂœ mĆŻĆŸe bĂœt pouĆŸit k simulaci pro sbÄr dat a kontrolnĂ systĂ©my pro vodnĂ elektrĂĄrny v prostĆedĂ Matlab / Simulink a TrueTime Simulink knihovnu. UvaĆŸovanĂĄ elektrĂĄrna sestĂĄvĂĄ z vodnĂ turbĂny pĆipojenĂ© k synchronnĂmu generĂĄtoru s budicĂ soustavou, generĂĄtor je pĆipojen k veĆejnĂ© elektrickĂ© sĂti. SimulacĂ vodnĂ turbĂny a synchronnĂho generĂĄtoru lze provĂ©st pomocĂ rĆŻznĂœch simulaÄnĂch nĂĄstrojĆŻ. V tĂ©to prĂĄci je upĆednostĆovĂĄn SIMULINK / MATLAB pĆed jinĂœmi nĂĄstroji k modelovĂĄnĂ dynamik vodnĂ turbĂny a synchronnĂho stroje. Program s prostĆedĂm MATLAB SIMULINK vyuĆŸĂvĂĄ k ĆeĆĄenĂ schematickĂœ model vodnĂ elektrĂĄrny sestavenĂœ ze zĂĄkladnĂch funkÄnĂch blokĆŻ. Tento pĆĂstup je pedagogicky lepĆĄĂ neĆŸ komplikovanĂ© kĂłdy jinĂœch softwarovĂœch programĆŻ. Knihovna programu Simulink obsahuje funkÄnĂ bloky, kterĂ© mohou bĂœt spojovĂĄny, upravovĂĄny a modelovĂĄny. K vytvoĆenĂ a simulovĂĄnĂ internetovĂœch a Real Time systĂ©mĆŻ je moĆŸnĂ© pouĆŸĂt budâ knihovnu simulinku Real-Time nebo TRUETIME, v prĂĄci byla pouĆŸita knihovna TRUETIME.Hydropower has now become the best source of electricity on earth. It is produced due to the energy provided by moving or falling water. History proves that the cost of this electricity remains constant over the year. Because of the many advantages, most of the countries now have hydropower as the source of major electricity producer. The most important advantage of hydropower is that it is green energy, which mean that no air or water pollutants are produced, also no greenhouse gases like carbon dioxide are produced which makes this source of energy environment-friendly. It prevents us from the danger of global warming. Using internet techniques to control several hydroelectric plants has very important advantages, as reducing operating costs and the flexibility of meeting changes of energy demand occurred in consumption side. Also it is very effective to confront large disturbances of electrical grid, such as adding or removing large loads, and faults. In the other hand, data acquisition systems provides very useful information for both typical and scientific analysis, such as economical costs reducing, fault prediction systems, demand prediction, maintenance schedules, decision support systems and many other benefits. This thesis describes a generalized model which can be used to simulate a data acquisition and control system of hydroelectric power plant using MATLAB/SIMULINK and TrueTime simulink library. The plant considered consists of hydro turbine connected to synchronous generator with excitation system, and the generator is connected to public grid. Simulation of hydro turbine and synchronous generator can be done using various simulation tools, In this work, SIMULINK/MATLAB is favored over other tools in modeling the dynamics of a hydro turbine and synchronous machine. The SIMULINK program in MATLAB is used to obtain a schematic model of the hydro plant by means of basic function blocks. This approach is pedagogically better than using a compilation of program code as in other software programs .The library of SIMULINK software programs includes function blocks which can be linked and edited to model. Either Simulink Real-Time library or TrueTime library can be used to build and simulate internet and real time systems, in this thesis the TrueTime library was used.
Configuration of Distributed Message Converter Systems using Performance Modeling
To find a configuration of a distributed system satisfying performance goals is a complex search problem that involves many design parameters, like hardware selection, job distribution and process configuration. Performance models are a powerful tools to analyse potential system configurations, however, their evaluation is expensive, such that only a limited number of possible configurations can be evaluated. In this paper we present a systematic method to find a satisfactory configuration with feasible effort, based on a two-step approach. First, using performance estimates a hardware configuration is determined and then the software configuration is incrementally optimized evaluating Layered Queueing Network models. We applied this method to the design of performant EDI converter systems in the financial domain, where increasing message volumes need to be handled due to the increasing importance of B2B interaction
Distributed photovoltaic systems: Utility interface issues and their present status
Major technical issues involving the integration of distributed photovoltaics (PV) into electric utility systems are defined and their impacts are described quantitatively. An extensive literature search, interviews, and analysis yielded information about the work in progress and highlighted problem areas in which additional work and research are needed. The findings from the literature search were used to determine whether satisfactory solutions to the problems exist or whether satisfactory approaches to a solution are underway. It was discovered that very few standards, specifications, or guidelines currently exist that will aid industry in integrating PV into the utility system. Specific areas of concern identified are: (1) protection, (2) stability, (3) system unbalance, (4) voltage regulation and reactive power requirements, (5) harmonics, (6) utility operations, (7) safety, (8) metering, and (9) distribution system planning and design
[Report of] Specialist Committee V.4: ocean, wind and wave energy utilization
The committee's mandate was :Concern for structural design of ocean energy utilization devices, such as offshore wind turbines, support structures and fixed or floating wave and tidal energy converters. Attention shall be given to the interaction between the load and the structural response and shall include due consideration of the stochastic nature of the waves, current and wind
Systems study for an Integrated Digital-Electric Aircraft (IDEA)
The results of the Integrated Digital/Electric Aircraft (IDEA) Study are presented. Airplanes with advanced systems were, defined and evaluated, as a means of identifying potential high payoff research tasks. A baseline airplane was defined for comparison, typical of a 1990's airplane with advanced active controls, propulsion, aerodynamics, and structures technology. Trade studies led to definition of an IDEA airplane, with extensive digital systems and electric secondary power distribution. This airplane showed an improvement of 3% in fuel use and 1.8% in DOC relative to the baseline configuration. An alternate configuration, an advanced technology turboprop, was also evaluated, with greater improvement supported by digital electric systems. Recommended research programs were defined for high risk, high payoff areas appropriate for implementation under NASA leadership
European White Book on Real-Time Power Hardware in the Loop Testing : DERlab Report No. R- 005.0
The European White Book on Real-Time-Powerhardware-in-the-Loop testing is intended to serve as a reference document on the future of testing of electrical power equipment, with speciïŹ c focus on the emerging hardware-in-the-loop activities and application thereof within testing facilities and procedures. It will provide an outlook of how this powerful tool can be utilised to support the development, testing and validation of speciïŹ cally DER equipment. It aims to report on international experience gained thus far and provides case studies on developments and speciïŹ c technical issues, such as the hardware/software interface. This white book compliments the already existing series of DERlab European white books, covering topics such as grid-inverters and grid-connected storag
Electrodynamic tether system study
The purpose of this program is to define an Electrodynamic Tether System (ETS) that could be erected from the space station and/or platforms to function as an energy storage device. A schematic representation of the ETS concept mounted on the space station is presented. In addition to the hardware design and configuration efforts, studies are also documented involving simulations of the Earth's magnetic fields and the effects this has on overall system efficiency calculations. Also discussed are some preliminary computer simulations of orbit perturbations caused by the cyclic/night operations of the ETS. System cost estimates, an outline for future development testing for the ETS system, and conclusions and recommendations are also provided
Advanced sensors technology survey
This project assesses the state-of-the-art in advanced or 'smart' sensors technology for NASA Life Sciences research applications with an emphasis on those sensors with potential applications on the space station freedom (SSF). The objectives are: (1) to conduct literature reviews on relevant advanced sensor technology; (2) to interview various scientists and engineers in industry, academia, and government who are knowledgeable on this topic; (3) to provide viewpoints and opinions regarding the potential applications of this technology on the SSF; and (4) to provide summary charts of relevant technologies and centers where these technologies are being developed
- âŠ