A new design methodology for multipulse rectifiers with Delta auto-connected transformers and a retrofit application in Adjustable Speed Drives (ASDs)

Multipulse rectifiers can replace a conventional six pulse three-phase rectifier (diode bridge) providing a DC voltage with low ripple, low Total Harmonic Distortion of current (THDi) and a high Power Factor (PF). In this context is presented a multipulse rectifier with generalized Delta-differential autotransformer topology, which can provide any level of DC output voltage for any level of three-phase AC input voltage. This paper presents all the possible configurations for Delta topology in order to choose, through graphics, one configuration that presents reduced weight and volume. The average voltage on the DC bus must be compatible with the DC voltage in the six pulse rectifier used in commercial ASDs. Therefore, it is possible to apply the retrofit technique to replace the conventional bridge rectifier by the proposed multipulse rectifier. Based on mathematic models and simulation results, an 18-pulse rectifier with Delta topology, 220 V of line voltage, 315 V of DC output, and rating 2.5 kW of power was designed, implemented and applied for three different commercial ASDs. Experimental results as voltage and current waveforms and results about PF and THDi will be presented. © 2012 IEEE.

Methodology analysis of a computational tool used in electronic circuit design

This paper considers the importance of using a top-down methodology and suitable CAD tools in the development of electronic circuits. The paper presents an evaluation of the methodology used in a computational tool created to support the synthesis of digital to analog converter models by translating between different tools used in a wide variety of applications. This tool is named MS 2SV and works directly with the following two commercial tools: MATLAB/Simulink and SystemVision. Model translation of an electronic circuit is achieved by translating a mixed-signal block diagram developed in Simulink into a lower level of abstraction in VHDL-AMS and the simulation project support structure in SystemVision. The method validation was performed by analyzing the power spectral of the signal obtained by the discrete Fourier transform of a digital to analog converter simulation model. © 2011 IEEE.

An Improved Design Procedure for LCC Resonant Filter of Dimmable Electronic Ballasts for Fluorescent Lamps, Based on Lamp Model

This paper presents an improved design methodology for determining the parameters used in the classical Series-Parallel Loaded Resonant (SPLR) filter employed in the switching frequency controlled dimmable electronic ballasts. According to the analysis developed in this paper, it is possible to evaluate some characteristics of the resonant filter during the dimming process, such as: range of switching frequency, phase shift and rms value of the current drained by the resonant filter + fluorescent lamp set.

An improved design procedure for LCC resonant filter of dimmable electronic ballasts for fluorescent lamps, based on lamp model

This paper presents an improved design methodology for the determination of the parameters used in the classical series-resonant parallel-loaded (SRPL) filter employed in the switching frequency controlled dimmable electronic ballasts. According to the analysis developed in this paper, it is possible to evaluate some important characteristics of the resonant filter during the dimming operation, such as: range of switching frequency, phase shift, and rms value of the current drained by the resonant filter + fluorescent lamp set. Experimental results are presented in order to validate the analyses developed in this paper. © 2005 IEEE.

Observer-based control design for switched affine systems and applications to DC-DC converters

This paper deals with the problem of establishing a state estimator for switched affine systems. For that matter, a modification on the Luenberger observer is proposed, the switched Luenberger observer, whose idea is to design one output gain matrix for each mode of the original system. The efficiency of the proposed method relies on a simplification on estimation error which is proved always valid, guaranteeing the estimation error to asymptotically converge to zero, for any initial state and switching law. Next, a dynamic output-dependent switching law is formulated. Then, design methodologies using linear matrix inequalities are proposed, which, to the authors's knowledge, have not yet been applied to this problem. Finally, observers for DC-DC converters are designed and simulated as application examples. © 2013 Brazilian Society for Automatics - SBA.

Diretrizes projetuais e as tendências: o design de móveis residenciais no pólo de Arapongas-PR

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Arte concreta: racionalismo e abstração como contribuições para o design - um estudo na obra de Geraldo de Barros

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise e proposta de elaboração de rótulo de embalagem de agrotóxicos (herbicida) por meio de metodologia de design ergonômico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Metodologia de design mediada por protótipos

Pós-graduação em Design - FAAC

Cogeneration design problem Computational complexity analysis and solution through an expert system

Purpose - The purpose of this paper is twofold: to analyze the computational complexity of the cogeneration design problem; to present an expert system to solve the proposed problem, comparing such an approach with the traditional searching methods available.Design/methodology/approach - The complexity of the cogeneration problem is analyzed through the transformation of the well-known knapsack problem. Both problems are formulated as decision problems and it is proven that the cogeneration problem is np-complete. Thus, several searching approaches, such as population heuristics and dynamic programming, could be used to solve the problem. Alternatively, a knowledge-based approach is proposed by presenting an expert system and its knowledge representation scheme.Findings - The expert system is executed considering two case-studies. First, a cogeneration plant should meet power, steam, chilled water and hot water demands. The expert system presented two different solutions based on high complexity thermodynamic cycles. In the second case-study the plant should meet just power and steam demands. The system presents three different solutions, and one of them was never considered before by our consultant expert.Originality/value - The expert system approach is not a "blind" method, i.e. it generates solutions based on actual engineering knowledge instead of the searching strategies from traditional methods. It means that the system is able to explain its choices, making available the design rationale for each solution. This is the main advantage of the expert system approach over the traditional search methods. On the other hand, the expert system quite likely does not provide an actual optimal solution. All it can provide is one or more acceptable solutions.

Diretrizes projetuais e o emprego das tendências: o design de móveis residenciais no polo de Arapongas/PR

Constant social, cultural and political changes influence directly people’s life and define their needs and tastes. Trends have the role of signaling through these facts people’s preferences regarding to objects and can, therefore be connected with great design, as it works with project that is a planning activity for future. In this context, this study aimed to characterize trend jobs in Brazilians home designing methodology. For both: theoretical aspects were studied that led to reasoning, a field research in five Furniture industries Pole of Arapongas/PR was done, and a research for possible developmental reference of furniture in Brazil. Results indicated: misused and mistaken concepts of trend and ignorance on how they operate lack of knowledge about industries sector consumer profile, the concern about sales and not with consumer as “furniture user” and finally, the existence of Brazilian referential sources, but the lack of skilled professionals that could decode these sources.

Procedimentos metodológicos em design gráfico voltados a jornais diários impressos: estudos e relatos de experiência

This paper summarizes a research that has been developed from the concern about a company’s strategic planning, once regarding the product development process and its methodological guidelines. Our goal was to check if there is an ideal methodology, peculiar to the graphic design, which could be applied to a printed newspaper condition. And then, we could deduce, according to the design practices in newspapers, its relevance. We did not intend to create a specific graphic design methodology for daily newspapers, nor the analysis of methods, but we wanted to emphasize that the familiarization with acknowledged methods in the field of visual communication, during the process of professional formation, might ease good choices in the work practice on design. The understanding of the gradual introduction of graphic design on printed daily newspapers brings about, thus, not only their visual improvement, but also allows that this kind of journalism (which depends on a graphic interface in order to make their product come true) reconsider the newspaper as a whole.