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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Diseño de un sistema de monitoreo y control de Ph de nutrientes para un prototipo de cultivo hidropónico usando PLC y software Scada

León Rojas, Billy Antonio 15 July 2017 (has links)
En la actualidad, el crecimiento poblacional y las consecuencias medioambientales generadas por diversas actividades realizadas por el hombre están reduciendo las áreas cultivables en el mundo y afectando la disponibilidad de los recursos naturales como el agua. Debido a ello, surge la importancia de la aplicación de novedosas técnicas agrícolas como la Hidroponía que al ser soportadas por la tecnología ofrecerían el sostenimiento alimentario mundial del futuro, el desarrollo socioeconómico y la conservación del ecosistema. En nuestro país, la agricultura tradicional es la técnica más realizada intensivamente la cual origina un elevado consumo de agua y la utilización de pesticidas que dañan en el tiempo las áreas cultivables. Además, los procesos de cultivo son realizados manualmente y muchas veces sin asesoría técnica. La existencia de técnicas como la Hidroponía trae muchas ventajas comparadas a la agricultura tradicional, y mejor aún, al ser soportada por la tecnología incrementaría la calidad y la productividad sin dañar el ecosistema. Con ello, nuestro país podría abrirse a mercados competitivos e impulsar su desarrollo tecnológico para la producción de plantas. El objetivo de esta tesis se centra en el diseño de un sistema de monitoreo y control del pH de nutrientes minerales para un prototipo de cultivo hidropónico recirculante usando PLC y software Scada. Con el control del pH se optimiza la calidad del producto pues se entrega a la planta los nutrientes minerales necesarios para su crecimiento eficientemente. No requiere de la tierra ni de pesticidas. Debido al sistema recirculante de los nutrientes se obtiene un menor consumo de agua y mayor oxigenación de las raíces de las plantas. Por otro lado, el monitoreo remoto permite obtener datos del procesos en tiempo real, un mejor análisis del comportamiento de la planta durante su crecimiento, información histórica del comportamiento del sistema, notificaciones instantáneas mediante alarmas, mejor toma de decisiones ante fallas, posibilidad de integración con las redes de telecomunicación, integración a diferentes aplicativos de oficina basados en Windows y completo control del proceso desde un centro de supervisión. / Tesis
92

Diseño del enlace de comunicaciones entre la central térmica de Chilca y la subestación eléctrica de San Juan

Horna von Ehren, Eduardo 23 November 2011 (has links)
El presente documento es el resultado de la investigación realizada en la Subestación Eléctrica de San Juan y la Central Térmica de Chilca para el diseño de un enlace de comunicaciones privado entre ellas, que permita transmitir la información del sistema de teleprotección, del sistema SCADA y del sistema de telefonía privada. Dada la necesidad de interconectar las instalaciones eléctricas en cuestión, para gestionar de manera óptima el servicio de energía, automatizando y controlando a distancia dichas instalaciones eléctricas, se requiere de un enlace de comunicaciones de alta confiabilidad y económicamente factible. El contenido de esta investigación abarca la problemática de las instalaciones eléctricas, los problemas en la red eléctrica, las tecnologías empleadas en enlaces de comunicaciones privados; así como la elección y el diseño del enlace por fibra óptica entre la S.E. San Juan y la C.T. Chilca como solución a la problemática existente. Se concluye que el diseño del enlace de comunicaciones por fibra óptica es altamente confiable, se proyecta a necesidades futuras que se presenten y tanto el costo de instalación, montaje e ingeniería, así como el costo de mantenimiento, son económicamente factibles. / Tesis
93

Interacção com uma arquitectura de componentes com independência de dispositivo e localização

Pereira, Carlos Ângelo de Paiva January 2002 (has links)
Dissertação apresentada para obtenção do grau de Mestre em Engenharia Electrotécnica e de Computadores, na Faculdade de Engenharia da Universidade do Porto, sob a orientação do professor Dpoutor João António Correia Lopes
94

Evaluation and Implementation of SCADA Systems / Utvärdering och implementering av processdatorsystem

Stolpe, Pär January 2001 (has links)
<p>In this bachelor thesis a comparison and evaluation of six different process visualization programs has been made. The purpose of the comparison is to find a suitable program for an experiment in control, held at Linköpings universitet, but also to get an overview of the market at the time this report was written. </p><p>After the evaluation an implementation is carried out with the programs that were bought. RSLogix, InTouch, InSQL and SuiteVoyager, one programming tool, one visualization tool, a database-manager and a web-portal for interaction over the Internet.</p>
95

Analyzing Non-Functional Capabilities of ICT Infrastructures Supporting Power System Wide Area Monitoring and Control

Chenine, Moustafa January 2013 (has links)
The strain on modern electrical power systems has led to an ever-increasing utilization of new information and communication technologies (ICT) to improve their efficiency and reliability. Wide area monitoring and control (WAMC) systems offer many opportunities to improve the real-time situational awareness in the power system. These systems are essen-tially SCADA systems but with continuous streaming of measurement data from the power system. The quality of WAMC systems and the applications running on top of them are heavily, but not exclusively, dependent on the underlying non-functional quality of the ICT systems. From an ICT perspective, the real-time nature of WAMC systems makes them susceptible to variations in the quality of the supporting ICT systems. The non-functional qualities studied as part of this research are performance, interoperability and cyber security. To analyze the performance of WAMC ICT systems, WAMC applications were identified, and their requirements were elicited. Furthermore, simulation models capturing typical utility communication infrastructure architectures were implemented. The simulation studies were carried out to identify and characterize the latency in these systems and its impact on data quality in terms of the data loss. While performance is a major and desirable quality, other non-functional qualities such as interoperability and cyber security have a significant impact on the usefulness of the sys-tem. To analyze these non-functional qualities, an enterprise architecture (EA) based framework for the modeling and analysis of interoperability and cyber security, specialized for WAMC systems, is proposed. The framework also captures the impact of cyber security on the interoperability of WAMC systems. Finally, a prototype WAMC system was imple-mented to allow the validation of the proposed EA based framework. The prototype is based on existing and adopted open-source frameworks and libraries. The research described in this thesis makes several contributions. The work is a systematic approach for the analysis of the non-functional quality of WAMC ICT systems as a basis for establishing the suitability of ICT system architectures to support WAMC applications. This analysis is accomplished by first analyzing the impact of communication architectures for WAMC systems on the latency. Second, the impact of these latencies on the data quali-ty, specifically data currency (end to end delay of the phasor measurements) and data in-completeness (i.e., the percentage of phasor measurements lost in the communication), is analyzed. The research also provides a framework for interoperability and cyber security analysis based on a probabilistic Monte Carlo enterprise architecture method. Additionally, the framework captures the possible impact of cyber security on the interoperability of WAMC data flows. A final result of the research is a test bed where WAMC applications can be deployed and ICT architectures tested in a controlled but realistic environment. / <p>QC 20130218</p>
96

Evaluation and Implementation of SCADA Systems / Utvärdering och implementering av processdatorsystem

Stolpe, Pär January 2001 (has links)
In this bachelor thesis a comparison and evaluation of six different process visualization programs has been made. The purpose of the comparison is to find a suitable program for an experiment in control, held at Linköpings universitet, but also to get an overview of the market at the time this report was written. After the evaluation an implementation is carried out with the programs that were bought. RSLogix, InTouch, InSQL and SuiteVoyager, one programming tool, one visualization tool, a database-manager and a web-portal for interaction over the Internet.
97

Cyber security in power systems

Sridharan, Venkatraman 06 April 2012 (has links)
Many automation and power control systems are integrated into the 'Smart Grid' concept for efficiently managing and delivering electric power. This integrated approach created several challenges that need to be taken into consideration such as cyber security issues, information sharing, and regulatory compliance. There are several issues that need to be addressed in the area of cyber security. Currently, there are no metrics for evaluating cyber security and methodologies to detect cyber attacks are in their infancy. There is a perceived lack of security built into the smart grid systems, but there is no mechanism for information sharing on cyber security incidents. In this thesis, we discuss the vulnerabilities in power system devices, and present ideas and a proposal towards multiple-threat system intrusion detection. We propose to test the multiple-threat methods for cyber security monitoring on a multi-laboratory test bed, and aid the development of a SCADA test bed, to be constructed on the Georgia Tech Campus.
98

Control of Smart Building Using Advanced SCADA

Samuel, Vivin Thomas 01 January 2013 (has links)
ABSTRACT For complete control of the building, a proper SCADA implementation and the optimization strategy has to be build. For better communication and efficiency a proper channel between the Communication protocol and SCADA has to be designed. This paper concentrate mainly between the communication protocol, and the SCADA implementation, for a better optimization and energy savings is derived to large scale industrial buildings. The communication channel used in order to completely control the building remotely from a distant place. For an efficient result we consider the temperature values and the power ratings of the equipment so that while controlling the equipment, we are setting a threshold values for FDD technique implementation. Building management system became a vital source for any building to maintain it and for safety purpose. Smart buildings, refers to various distinct features, where the complete automation system, office building controls, data center controls. ELC's are used to communicate the load values of the building to the remote server from a far location with the help of an Ethernet communication channel. Based on the demand fluctuation and the peak voltage, the loads operate differently increasing the consumption rate thus results in the increase in the annual consumption bill. In modern days, saving energy and reducing the consumption bill is most essential for any building for a better and long operation. The equipment - monitored regularly and optimization strategy is implemented for cost reduction automation system. Thus results in the reduction of annual cost reduction and load lifetime increase.
99

Real-Time Demand Estimation for Water Distribution Systems

Kang, Doo Sun January 2008 (has links)
The goal of a water distribution system (WDS) is to supply the desired quantity of fresh water to consumers at the appropriate time. In order to properly operate a WDS, system operators need information about the system states, such as tank water level, nodal pressure, and water quality for the system wide locations. Most water utilities now have some level of SCADA (Supervisory Control and Data Acquisition) systems providing nearly real-time monitoring data. However, due to the prohibitive metering costs and lack of applications for the data, only portions of systems are monitored and the use of the SCADA data is limited. This dissertation takes a comprehensive view of real-time demand estimation in water distribution systems. The goal is to develop an optimal monitoring system plan that will collect appropriate field data to determine accurate, precise demand estimates and to understand their impact on model predictions. To achieve that goal, a methodology for real-time demand estimates and associated uncertainties using limited number of field measurements is developed. Further, system wide nodal pressure and chlorine concentration and their uncertainties are predicted using the estimated nodal demands. This dissertation is composed of three journal manuscripts that address these three key steps beginning with uncertainty evaluation, followed by demand estimation and finally optimal metering layout.The uncertainties associated with the state estimates are quantified in terms of confidence limits. To compute the uncertainties in real-time alternative schemes that reduce computational efforts while providing good statistical approximations are evaluated and verified by Monte Carlo simulation (MCS). The first order second moment(FOSM) method provides accurate variance estimates for pressure; however, because of its linearity assumption it has limited predictive ability for chlorine under unsteady conditions. Latin Hypercube sampling (LHS) provides good estimates of prediction uncertainty for chlorine and pressure in steady and unsteady conditions with significantly less effort.For real-time demand estimation, two recursive state estimators; tracking state estimator (TSE) based on weighted least squares (WLS) scheme and Kalman filter (KF), are applied. In addition, in order to find available field data types for demand estimation, comparative studies are performed using pipe flow rate and nodal pressure head as measurements. To reduce the number of unknowns and make the system solvable, nodes with similar user characteristics are grouped and assumed to have same demand pattern. The uncertainties in state variables are quantified in terms of confidence limits using the approximate methods (i.e., FOSM and LHS). Results show that TSE with pipe flow rates as measurements provide reliable demand estimations. Also, the model predictions computed using the estimated demands match well with the synthetically generated true values.Field measurements are critical elements to obtaining quality real-time state estimates. However, the limited number of metering locations has been a significant obstacle for the real-time studies and identifying locations to best gain information is critical. Here, an optimal meter placement (OMP) is formulated as a multi-objective optimization problem and solved using a multi-objective genetic algorithm (MOGA) based on Pareto-optimal solutions. Results show that model accuracy and precision should be pursued at the same time as objectives since both measures have trade-off relationship. GA solutions were improvements over the less robust methods or designers' experienced judgment.
100

A Methodology For Calculating Hydraulic System Reliability Of Water Distribution Networks

Misirdali, Metin 01 January 2003 (has links) (PDF)
A completely satisfactory water distribution network should fulfill its basic requirements such as providing the expected quality and quantity of water with the desired residual pressures during its lifetime. A water distribution network should accommodate the abnormal conditions caused by failures. These types of failures can be classified into two groups / mechanical failures and hydraulic failures. Mechanical failure is caused due to malfunctioning of the network elements such as pipe breakage, power outage and pump failure. On the other hand, hydraulic failure, considers system failure due to distributed flow and pressure head which are inadequate at one or more demand points.This study deals with the calculation of the hydraulic system reliability of an existing water distribution network regarding the Modified Chandapillai model while calculating the partially satisfied nodes. A case study was carried out on a part of Ankara Water Distribution Network, N8-1. After the modeling of the network, skeletonization and determination of nodal service areas were carried out. The daily demand curves for the area were drawn using the data that were taken from SCADA of the water utility. The daily demand curves of different days were joined and one representative mean daily demand curve together with the standard deviation values was obtained. The friction coefficient values of the pipes and storage tank water elevation were taken as other uncertainty parameters for the model. Bao and Mays (1990) approach were carried together with the hydraulic network solver program prepared by Nohutcu (2002) based on Modified Chandapillai model. The sensitivity analysis for the effects of system characteristics and model assumptions were carried out to see the effects of the parameters on the calculations and to investigate the way of improving the hydraulic reliability of the network. The storage tank should be located at a higher level for improving the reliability of the network. Also having the storage tank water level nearly full level helps in improving the reliability in daily management. Moreover, the hydraulic system reliability is highly dependent on the pumps as the lowest reliability factors were the ones with the no pump scenarios. Determining the required pressures for nodes are very important since they are the dominant factors that effects the reliability calculations. On the other hand, friction coefficient parameters and type of probability distribution function do not have dominant effect on the results. Results of this study were helpful to see the effects of different parameters on the hydraulic reliability calculations and for assessment of the methods for improving the reliability for the network.

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