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Aplicações de controle e supervisão distribuídas em subestações de energia elétrica através do uso de relés digitais de proteção; Control and supervision application distributed in electrical energy substations with the use of digital protection relays

Chemin Netto, Ulisses
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 19/03/2008 PT
Relevância na Pesquisa
36.11%
Na primeira década deste século os equipamentos de proteção com tecnologia digital sinalizaram um novo paradigma para a composição dos sistemas de proteção. É fato também que essa tecnologia convive com suas antecessoras, que por força de sua longa predominância ainda exercem alguma influência sobre o pensamento, concepção e operação dos sistemas de proteção. Esses novos equipamentos multifunções, em geral, estão subutilizados, sendo o seu potencial ainda não empregado ou explorado em profundidade. Os relés digitais possuem grande capacidade para resolver alguns dos problemas intrínsecos aos sistemas elétricos de potência, seja do ponto de vista das funções de medição, supervisão, controle, análise de eventos (registros seqüenciais e oscilografias), proteção e comunicação. Como fato, tem-se que uma das vantagens associadas à utilização da capacidade de controle e automação dos relés digitais está em seu potencial de simplificar a concepção dos painéis que compõem as instalações de potência. Isso diminui os tempos de construção, comissionamento e manutenção, além de agregar maior confiabilidade e flexibilidade ao controle. Como proposta fundamental deste trabalho, pretende-se investigar como utilizar adequadamente as capacidades de programação de usuário dos relés digitais de proteção para compor soluções de controle...

Análise do comportamento sísmico das partes internas de um equipamento de proteção ambiental.; Analysis of seismic behavior of the internal parts of an environmental control equipment.

Orbolato, Leandro Marino Takazono
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 15/10/2012 PT
Relevância na Pesquisa
46.01%
Neste trabalho o comportamento sísmico das partes internas de um equipamento de proteção ambiental é estudado. O equipamento, um precipitador eletrostático, é composto basicamente de uma grande caixa de metal elevada, que contem eletrodos positivos e negativos responsáveis pela coleta de material particulado no fluxo de gases industriais. Esses componentes se comportam como pêndulos. No modelo foram considerados os deslocamentos sísmicos horizontais em duas direções ortogonais. De especial interesse está o fato de os eletrodos terem a liberdade de oscilar no plano de uma direção, mas não no seu plano perpendicular. Serão analisados quatro modelos com um, dois, três graus de liberdade, e um com três graus de liberdade linearizado. O modelo mais completo considera como graus de liberdade e coordenadas generalizadas os dois deslocamentos horizontais, e o deslocamento angular do pendulo. Foi adotada a formulação Lagrangeana para derivar as equações de movimento do modelo. As equações diferenciais do movimento de segunda ordem obtidas apresentam um comportamento não linear. Os movimentos sísmicos, que são estocásticos por natureza, serão simulados por meio de um registro sísmico existente, arbitrariamente escolhido. A obtenção dos parâmetros do modelo a ser estudado é de especial interesse para a melhor previsão do comportamento do equipamento quando solicitado a esforços sísmicos. A integração numérica do modelo matemático é efetuada...

Performance evaluation on electronic control systemsfor field sprayers using programmable logic controllers

Antuniassi, U. R.; Figueiredo, Z. N.; de Carvalho, WPA; Pinto, D. R.; Zazueta, F.; Xin, J.
Fonte: Amer Soc Agr Engineers Publicador: Amer Soc Agr Engineers
Tipo: Conferência ou Objeto de Conferência Formato: 272-278
ENG
Relevância na Pesquisa
46.04%
The aim of this study was to develop a laboratory method for time response evaluation on electronically controlled spray equipment using Programmable Logic Controllers (PLCs). For that purpose, a PLC controlled digital drive inverter was set up to drive an asynchronous electric motor linked to a centrifugal pump on a experimental sprayer equipped with electronic flow control. The PLC was operated via RS232 serial communication from a PC computer. A user program was written to control de motor by adjusting the following system variables, all related to the motor speed: time stopped; ramp up and ramp down times, time running at a given constant speed and ramp down time to stop the motor. This set up was used in conjunction with a data acquisition system to perform laboratory tests with an electronically controlled sprayer. Time response for pressure stabilization was measured while changing the pump speed by +/-20%. The results showed that for a 0.2 s ramp time increasing the motor speed, as an example, an AgLogix Flow Control system (Midwest Technologies Inc.) took 22 s in average to readjust the pressure. When decreasing the motor speed, this time response was down to 8 s. General results also showed that this kind of methodology could make easier the definition of standards for tests on electronically controlled application equipment.

On Nonlinear Dynamics and Control of A Particular Portal Frame Foundation Model, Excited by a Non-Ideal Motor

Balthazar, José Manoel; Felix, Jorge Luis Palacios; Brasil, Reyolando Manoel Lopes Rabelo da Fonseca
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Conferência ou Objeto de Conferência Formato: 371-378
ENG
Relevância na Pesquisa
45.8%
The nonlinear dynamic response and a nonlinear control method of a particular portal frame foundation for an unbalanced rotating machine with limited power (non-ideal motor) are examined. Numerical simulations are performed for a set of control parameters (depending on the voltage of the motor) related to the static and dynamic characteristics of the motor. The interaction of the structure with the excitation source may lead to the occurrence of interesting phenomena during the forward passage through the several resonance states of the systems. A mathematical model having two degrees of freedom simplifies the non-ideal system. The study of controlling steady-state vibrations of the non-ideal system is based on the saturation phenomenon due to internal resonance.

Estudo experimental de um controle adaptativo para um sistema de refrigeração; Experimental study of a refrigeration system using an adaptative control

Garcia, Francisco Ernesto Moreno
Fonte: Universidade Federal de Uberlândia Publicador: Universidade Federal de Uberlândia
Tipo: Dissertação
POR
Relevância na Pesquisa
36.11%
Este trabalho trata do uso do e um controle adaptativo num sistema de refrigeração por compressão de vapor visando economia de energia, utilizando R-22 como fluido de trabalho. O equipamento experimental é composto por um compressor semi-hermético alternativo, condensador e evaporador de tubos concêntricos resfriados a água e válvula de expansão termostática com equalização manual e variador de freqüência para controlar a velocidade de rotação do compressor. O sistema foi totalmente instrumentado, usando sensores de temperaturas tipo PT-100 na entrada e saída de cada componente, sensores de pressão piezo-resistivos, medidor de vazão de refrigerante tipo coriolis, placa condicionadora de sinais com saída analógica, uso de controlador lógico programável (CLP) para digitalizar os sinais analógicos, software de monitoração e operação do sistema, implementado em LABVIEW, uso de controle difuso – adaptativo para controle da velocidade de rotação do compressor, uso de PID para controle de temperatura de alimentação da água para o evaporador, torre de resfriamento para resfriar a água saindo do condensador. O estudo utilizou alem do controlador difuso, controle On-Off e controle PI, analisando os resultados obtidos...

INNOVATIVE TECHNOLOGIES FOR THE VIBRATION CONTROL OF EQUIPMENT IN CRITICAL FACILITIES

REGGIO, ANNA
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
EN
Relevância na Pesquisa
36.16%
The present thesis settles in the framework of the dynamic modelling, seismic mitigation and permanent health monitoring of equipment in critical facilities. The main objective is to assess the feasibility and the effectiveness of innovative mitigation Technologies including: the passive isolation of a single equipment (equipment isolation systems); the passive isolation of a raised floor, on which a group of several equipment is anchored (isolated raised-floor systems); a non-conventional Tuned Mass Damper (TMD), realized by converting a large mass already present on the structure, e.g. the mass of an equipment, into a tuned mass, in order to reduce the structural response. The area of research is believed to have the potential for a wide application, since a still limited number of authors has addressed the theoretical and technical issues associated with the seismic design and protection of equipment. As a result, international seismic codes and standards also appear to be inadequate in this regard. Furthermore, the proposed technologies give the opportunity of addressing topics of significant scientific interest: the analysis of the dynamic interaction between an equipment and its supporting structure, generally neglected in current Literature and seismic codes; the definition of reduced-order generalized models...

An evaluation and comparison of the Army's acquisition plans for two tactical command control and communications systems: mobile subscriber equipment and single channel ground and airborne radio system

Williams, Denise F.; Ebener, Ralph I., Jr.
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado Formato: viii, 58 p.
EN_US
Relevância na Pesquisa
46.05%
Approved for public release, distribution is unlimited; This thesis evaluates the Acquisition Plans of two US Army Command, Control and Communications (C3) systems: Mobile Subscriber Equipment (MSE) and the Single Channel Ground and Airborne Radio System (SINCGARS), both of which are components of the Army Tactical Command and Control System (ATCCS). The study examines the defense acquisition process through the comparison of the Acquisition Plans and lessons learned for these two programs, and determines if there is an optimal strategy for the Army to use when acquiring tactical C3 systems. An analysis of the strengths and weaknesses of the two Acquisition Plans, and an evaluation of the similarities and differences of two programs, concludes that the MSE Acquisition Plan proved more successful than its SINCGARS counterparts because of its Non-Developmental Item approach. This study recommends maximum use of the NDI strategy for acquiring C3 systems whenever possible.; Captain, United States Army; Captain, United States Army

China : Air Pollution and Acid Rain Control - The Case of Shijiazhuang and the Changsha Triangle Area

World Bank
Fonte: Washington, DC Publicador: Washington, DC
Tipo: Publications & Research :: ESMAP Paper; Publications & Research
ENGLISH; EN_US
Relevância na Pesquisa
46.01%
This study, and the associated technical assistance project, has three main objectives. The first is to help localities in China address several questions related to the planning, and implementation of SO2 emissions, and acid rain control: What are the environmental consequences, specifically for localities of different pollution control strategies, in terms of the impacts on human health, agricultural productivity, and other sectors and activities? What are the relative costs of different sulfur emission reduction plans? Will the proposed strategies enable localities to meet the environmental targets set by the central government? The second objective is to assist with capacity building, and training in China. to enable cities and regions to carry out environmental, and economic analyses of sulfur emission impacts, and control programs. The third objective is to provide a forum for discussion with the central government, primarily the State Environmental Protection Administration (SEPA), on the results of the case studies...

Fractional control with a smith predictor

Jesus, Isabel S.; Machado, J. A. Tenreiro
Fonte: ASME - American Society of Mechanical Engineers Publicador: ASME - American Society of Mechanical Engineers
Tipo: Artigo de Revista Científica
Publicado em //2011 ENG
Relevância na Pesquisa
45.8%
The advantageous use of fractional calculus (FC) in the modeling and control of many dynamical systems has been recognized. In this paper, we study the control of a heat diffusion system based on the application of the FC concepts. Several algorithms are investigated and compared, when integrated within a Smith predictor control structure. Simulations are presented assessing the performance of the proposed fractional algorithms.

Dynamic Image Based Visual Servo Control For An Aerial Robot: Theory and Experiments

Mahony, Robert; Le Bras, Florent; Hamel, Tarek; Binetti, Paolo
Fonte: Taylor & Francis Group Publicador: Taylor & Francis Group
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.78%
This article considers the question of dynamic image-based visual servo control for a vertical take-off and landing unmanned aerial vehicle. The visual targets considered are colored blobs on a flat surface to which the normal direction is known. A fully

Multiple model adaptive control with safe switching

Anderson, Brian; Brinsmead, Thomas; Liberzon, Daniel; Morse, A
Fonte: John Wiley & Sons Inc Publicador: John Wiley & Sons Inc
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.82%
The purpose of this paper is to marry the two concepts of multiple model adaptive control and safe adaptive control. In its simplest form, multiple model adaptive control involves a supervisor switching among one of a finite number of controllers as more

A practical Visual Servo Control for a Unmanned Aerial Vehicle

Guenard, Nicolas; Hamel, Tarek; Mahony, Robert
Fonte: OmniPress Publicador: OmniPress
Tipo: Conference paper
Relevância na Pesquisa
45.81%
An image-based visual servo control is presented for an Unmanned aerial vehicle (UAV) capable of stationary or quasi-stationary flight. The proposed control design addresses visual servo of 'eye-in-hand' type systems. The control of the position and orien

Modeling and Control of an Equipment Isolation System for Critical Facilities

Harvey, Jr., Philip Scott
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Tese de Doutorado
Publicado em //2012
Relevância na Pesquisa
46.17%

The primary focus of this thesis is on the modeling and control of a high performance vibration isolation platform used in the protection of mission-critical equipment. The equipment isolation system (EIS) consists of a pair of frames—the bottom-frame contains four concave-up bowls, the top-frame contains four concave-down bowls—between which four rigid steel balls can roll, effectively decoupling the top-frame (and equipment) from the base excitation. In order for the four balls to remain in contact with the dishes during times of large angular rotation, the platform is assumed to conform to a saddle shape. Developing a high-fidelity analytical model to capture the nonlinear nature of the EIS requires (i) enforcement of kinematic rolling constraints to the translational and rotational dynamics of the platform center, (ii) precise measurements of the bowl profiles and an accompanying parameterized model, and (iii) calibrating a linear-viscous damping model to experimental free-responses. To this end, nonholonomic equations of state are found from the d'Alembert-Lagrange principle which incorporates velocity constraints via Lagrange multipliers. The bowl profiles are measured using high-resolution photogrammetry and establish the system's potential energy function. Bowl shape parameters and damping parameters are optimized using a Levenberg-Marquardt least squares algorithm; the damping rate is shown to depend upon the mass of the isolated object.

To demonstrate the capabilities of the proposed model...

Utilization of statistical tools to identify assignable causes of variability and model performance of a wet electrostatic precipitator

Wuotinen, Jennifer
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
46.19%
The King's Landing Wastewater Treatment Plant treats industrial sewer wastewater from nearly 200 manufacturing buildings for Eastman Kodak Company located at Kodak Park in Rochester, NY. The average throughput for the facility is 28 million gallons of wastewater per day (MGD) and discharges the resulting effluent into the Genesee River. Through a series of physical, chemical, and biological treatment processes, materials are removed from the wastewater and sludge is produced. The sludge is conveyed through a belt press for dewatering prior to incineration. The dewatered sludge is sent to a multiple hearth incinerator with a secondary combustion chamber/afterburner for thermal treatment. From the combustion and incineration process, off-gases are produced. Therefore, air pollution control equipment is needed to treat the gas stream. At King's Landing, an induced draft fan creates negative pressure through the hearth along with a series of air pollution control equipment (APCE) consisting of a quench chamber, condenser/scrubber, venturi, entrainment separator, and a wet electrostatic precipitator (WESP). This equipment captures the components in the air stream through processes such as gas saturation, caustic neutralization, and electron particle collection. The WESP is a device that is used for fine particle collection in the range of 1 micron or less. Upon entereing the unit...

L ∞ -bounded robust control of nonlinear cascade systems

Huang, Shoudong; James, Matthew; Jiang, Zhong-Ping
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.82%
In this paper, we consider the L∞-bounded robust control problem for a class of nonlinear cascade systems with disturbances. Sufficient conditions are provided under which a hard bound is imposed on the system performance measure. The backstepping appro

A quantum Langevin formulation of risk-sensitive optimal control

James, Matthew
Fonte: Institute of Physics Publishing Publicador: Institute of Physics Publishing
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.83%
In this paper we formulate a risk-sensitive optimal control problem for continuously monitored open quantum systems modelled by quantum Langevin equations. The optimal controller is expressed in terms of a modified conditional state, which we call a risk-sensitive state, that represents measurement knowledge tempered by the control purpose. One of the two components of the optimal controller is dynamic, a filter that computes the risk-sensitive state. The second component is an optimal control feedback function that is found by solving the dynamic programming equation. The optimal controller can be implemented using classical electronics. The ideas are illustrated using an example of feedback control of a two-level atom.

Model Validation for Control and Controller Validation in a Prediction error Identification Framework - Part II: illustrations

Covers, Michel; Bombois, Xavier; Codrons, Bonoit; Scorletti, Gérard; Anderson, Brian
Fonte: Pergamon-Elsevier Ltd Publicador: Pergamon-Elsevier Ltd
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.83%
The results on model validation for control and controller validation in a prediction error identification framework are illustrated. The results are illustrated with two realistic identification and control design applications. The first is the control of a flexible mechanical system with a tracking objective and the second is the control of a ferrosilicon production process with a disturbance rejection objective.

Model Validation for Control and Controller Validation in a Prediction error Identification Framework - Part I

Gevers, Michel; Bombois, Xavier; Codrons, Bonoit; Scorletti, Gérard; Anderson, Brian
Fonte: Pergamon-Elsevier Ltd Publicador: Pergamon-Elsevier Ltd
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.84%
We propose a model validation procedure that consists of a prediction error identification experiment with a full order model. It delivers a parametric uncertainty ellipsoid and a corresponding set of parameterized transfer functions, which we call prediction error (PE) uncertainty set. Such uncertainty set differs from the classical uncertainty descriptions used in robust control analysis and design. We develop a robust control analysis theory for such uncertainty sets, which covers two distinct aspects: (1) Controller validation. We present necessary and sufficient conditions for a specific controller to stabilize - or to achieve a given level of performance with - all systems in such PE uncertainty set. (2) Model validation for robust control. We present a measure for the size of such PE uncertainty set that is directly connected to the size of a set controllers that stabilize all systems in the model uncertainty set. This allows us to establish that one uncertainty set is better tuned for robust control design than another, leading to control-oriented validation objectives.

Nonlinear H-∞ Control: Practicality of Implementing the Cheap Sensor Case

Helton, J W; James, Matthew; McEneaney, W M
Fonte: Institute of Electrical and Electronics Engineers (IEEE Inc) Publicador: Institute of Electrical and Electronics Engineers (IEEE Inc)
Tipo: Conference paper
Relevância na Pesquisa
45.81%
In [5] we introduced a recipe for nonlinear H∞ controllers which takes advantage of extra perfect measurements and stated a theorem to the effect that this controller yielded the best possible "H∞" performance. Pure state feedback is an extreme situat

Global power system control using generator excitation, PSS, FACTS devices and capacitor switching

Leung, Joseph S K; Hill, David; Ni, Yixin
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.82%
A novel power system control scheme is developed in this paper using a framework for coordinating dissimilar controllers at different locations. The control actions are formulated in the so-called global controller as a set of local controllers, namely the generator excitation controller, power system stabilizer (PSS), unified power flow controller (UPFC) and capacitor switching, which are coordinated to maintain transient angle stability, transient voltage stability and damping of long-term inter-area oscillations following a disturbance. The proposed coordinated control scheme is tested on a nine-bus example system.