Comparação do controle do inversor trifásico conectado à rede com filtro LCL considerando o amortecimento passivo e ativo

Distributed generation systems must fulfill standards specifications of current harmonics injected to the grid. In order to satisfy these grid requirements, passive filters are connected between inverter and grid. This work compares the characteristic response of the traditional inductive (L) filter with the inductive-capacitive-inductive (LCL) filter. It is shown that increasing the inductance L leads to a good ripple current suppression around the inverter switching frequency. The LCL filter provides better harmonic attenuation and reduces the filter size. The main drawback is the LCL filter impedance, which is characterized by a typical resonance peak, which must be damped to avoid instability. Passive or active techniques can be used to damp the LCL resonance. To address this issue, this dissertation presents a comparison of current control for PV grid-tied inverters with L filter and LCL filter and also discuss the use of active and passive damping for different regions of resonance frequency. From the mathematical models, a design methodology of the controllers was developed and the dynamic behavior of the system operating in closed loop was investigated. To validate the studies developed during this work, experimental results are presented using a three-phase 5kW experimental platform. The main components and their functions are discussed in this work. Experimental results are given to support the theoretical analysis and to illustrate the performance of grid-connected PV inverter system. It is shown that the resonant frequency of the system, and sampling frequency can be associated in order to calculate a critical frequency, below which is essential to perform the damping of the LCL filter. Also, the experimental results show that the active buffer per virtual resistor, although with a simple development, is effective to damp the resonance of the LCL filter and allow the system to operate stable within predetermined parameters.

Análise e proposição de estratégias de estimação e controle de velocidade para motores de indução trifásicos

This study presents a proposal of speed servomechanisms without the use of mechanical sensors (sensorless) using induction motors. A comparison is performed and propose techniques for pet rotor speed, analyzing performance in different conditions of speed and load. For the determination of control technique, initially, is performed an analysis of the technical literature of the main control and speed estimation used, with their characteristics and limitations. The proposed technique for servo sensorless speed induction motor uses indirect field-oriented control (IFOC), composed of four controllers of the proportional-integral type (PI): rotor flux controller, speed controller and current controllers in the direct and quadrature shaft. As the main focus of the work is in the speed control loop was implemented in Matlab the recursive least squares algorithm (RLS) for identification of mechanical parameters, such as moment of inertia and friction coefficient. Thus, the speed of outer loop controller gains can be self adjusted to compensate for any changes in the mechanical parameters. For speed estimation techniques are analyzed: MRAS by rotóricos fluxes MRAS by counter EMF, MRAS by instantaneous reactive power, slip, locked loop phase (PLL) and sliding mode. A proposition of estimation in sliding mode based on speed, which is performed a change in rotor flux observer structure is displayed. To evaluate the techniques are performed theoretical analyzes in Matlab simulation environment and experimental platform in electrical machinery drives. The DSP TMS320F28069 was used for experimental implementation of speed estimation techniques and check the performance of the same in a wide speed range, including load insertion. From this analysis is carried out to implement closed-loop control of sensorless speed IFOC structure. The results demonstrated the real possibility of replacing mechanical sensors for estimation techniques proposed and analyzed. Among these, the estimator based on PLL demonstrated the best performance in various conditions, while the technique based on sliding mode has good capacity estimation in steady state and robustness to parametric variations.

Análise hidromecânica do problema de fraturamento hidráulico

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2016.

Selection et controle de modes de deplacement pour un robot mobile autonome en environnements naturels

Autonomous navigation and locomotion of a mobile robot in natural environments remain a rather open issue. Several functionalities are required to complete the usual perception/decision/action cycle. They can be divided in two main categories : navigation (perception and decision about the movement) and locomotion (movement execution). In order to be able to face the large range of possible situations in natural environments, it is essential to make use of various kinds of complementary functionalities, defining various navigation and locomotion modes. Indeed, a number of navigation and locomotion approaches have been proposed in the literature for the last years, but none can pretend being able to achieve autonomous navigation and locomotion in every situation. Thus, it seems relevant to endow an outdoor mobile robot with several complementary navigation and locomotion modes. Accordingly, the robot must also have means to select the most appropriate mode to apply. This thesis proposes the development of such a navigation/locomotion mode selection system, based on two types of data: an observation of the context to determine in what kind of situation the robot has to achieve its movement and an evaluation of the behavior of the current mode, made by monitors which influence the transitions towards other modes when the behavior of the current one is considered as non satisfying. Hence, this document introduces a probabilistic framework for the estimation of the mode to be applied, some navigation and locomotion modes used, a qualitative terrain representation method (based on the evaluation of a difficulty computed from the placement of the robot's structure on a digital elevation map), and monitors that check the behavior of the modes used (evaluation of rolling locomotion efficiency, robot's attitude and configuration watching. . .). Some experimental results obtained with those elements integrated on board two different outdoor robots are presented and discussed.

The making of control : an ethnomethodology of choosing management accounting systems [La fabrique du controle : une ethnomethodologie du choix des outils de gestion]

This paper sets out to contribute to the literature on the design and the implementation of management control systems. To this end, we question what is discussed when a management control system is to be chosen and on what decision-making eventually rests. This study rests upon an ethnomethodology of the Salvation Army’s French branch. Operating in the dual capacity of a researcher and a counsellor to management, between 2000 and 2007, we have unrestricted access to internal data revealing the backstage of management control: discussions and interactions surrounding the choosing of control devices. We contribute to understanding the arising of a need for control, the steps and process followed to decide upon a management control system, and controls in nonprofits. [Cet article vise à contribuer à la littérature sur la mise en place des systèmes de contrôle de gestion. À cette fin, nous questionnons ce qui est discuté lors du choix d’un système de contrôle et sur quoi repose in fine la décision. Cet article est fondé sur une approche ethnométhodologique de l’Armée du Salut en France permise par notre double qualité de chercheurs mais également de conseiller auprès de la direction de l’organisation entre 2000 et 2007. Un accès illimité à des données internes nous permet ainsi de mettre en lumière les aspects méconnus et invisibles du contrôle de gestion : les discussions et interactions entourant le choix d’outils. Nous contribuons à la compréhension de l’émergence du besoin de contrôle, des étapes et du processus de choix d’outils et enfin du contrôle de gestion dans une organisation à but non lucratif.]

Parlamento aberto : transparência e controle social para um Congresso mais colaborativo

Traz os debates ocorridos durante a 1ª Reunião de Audiência Pública, realizada em abril de 2012, na Câmara dos Deputados, que discutiu o tema "Parlamento Aberto: Transparência e Controle Social para um Congresso mais Colaborativo".

Retroalimentação do controle interno para os órgãos centrais do sistema de planejamento e orçamento federal em questões estruturantes

Analisa o fluxo do processo de retroalimentação da CGU para órgãos centrais do Sistema de Planejamento e Orçamento Federal, bem como as possibilidades de retroalimentação da CGU a esses órgãos. Propõe a previsão na legislação de um Comitê Operacional e de um Comitê Estratégico do Ciclo de Gestão.

Legislação sobre o controle de poluição causada por motocicletas

Consultoria Legislativa - Área XI - Meio Ambiente e Direito Ambiental, Organização Territorial, Desenvolvimento Urbano e Regional.

Democratização e controle externo do Poder Judiciário

Consultoria Legislativa - Área I - Direito Constitucional, Eleitoral, Municipal, Administrativo Processo Legislativo e Poder Judiciário.

Inconstitucionalidade do controle do cumprimento das promessas de campanha eleitoral

Consultoria Legislativa - Área I - Direito Constitucional, Eleitoral, Municipal, Direito Administrativo, Processo Legislativo e Poder Judiciário.

Aplicabilidade da teoria do desvio de poder no controle da constitucionalidade de atos legislativos : contornos, limites e superação pela teoria dos princípios

Consultoria Legislativa - Área VIII - Área de Direito Administrativo e de Administração Pública.

Representação, participação política e controle social : instituições, atores e história

Consultoria Legislativa - Área XIX - Ciência Política, Sociologia Política História, Relações Internacionais.

Proposta legislativa de criação de conta corrente específica com as mesmas condições fiscais concedidas aos planos de previdência privada

Consultoria Legislativa - Área VII - Sistema Financeiro, Direito Comercial, Econômico e Defesa do Consumidor.

Controle externo da atividade policial

Consultoria Legislativa - Área XVII - Segurança e Defesa Nacional.

Controle legislativo de constitucionalidade de proposições : recurso contra pareceres da Comissão de Constituição e Justiça e de Redação da Câmara dos Deputados

Aborda o controle de constitucionalidade no processo legislativo, realizado pela Comissão de Constituição e Justiça e de Redação da Câmara dos Deputados. Analisa os seguintes pontos: formas de controle de constitucionalidade no Brasil e no direito comparado; a natureza dos pareceres da CCJR; a necessidade do direito a recurso contra os chamados pareceres terminativos. Propõe mudança no Regimento Interno da Câmara dos Deputados, sugerindo texto de projeto de resolução.