“SE SEUS PROJETOS FOREM PARA UM ANO,SEMEIE O GRÂO.SE FOREM PARA DEZ ANOS,PLANTE UMA ÁRVORE.SE FOREM PARA CEM ANOS,EDUQUE O POVO.”

“Sixty years ago I knew everything; now I know nothing; education is a progressive discovery of our own ignorance. Will Durant”

OBRIGADO DEUS PELA VIDA,PROTEGENOS E GUARDANOS DE TODO MAL


SAO PAULO BRASIL

domingo, 24 de maio de 2015

Y. Kadoshima, K. Koiwa, J. Itoh, F. Anne, A. Gerlaud: "Surge Voltage Suppression Methods for Three-phase to Single-phase Matrix Converter", The Applied Power Electronics Conference and Exposition 2015, Vol. , No. , pp. 115-121 (2015)





Y. Kadoshima, K. Koiwa, J. Itoh, F. Anne, A. Gerlaud: "Surge Voltage Suppression Methods for Three-phase to Single-phase Matrix Converter", The Applied Power Electronics Conference and Exposition 2015, Vol. , No. , pp. 115-121 (2015)
 Abstract—This paper discusses surge voltage suppression methods in order to design a large capacity three-phase to single-phase matrix converter which is used in AC-DC converters. In order to reduce the surge voltage, the design criteria based on the flow chart of a laminated bus bar (LBB) for the three-phase to single-phase matrix converter is clarified to achieve the lowest stray inductance. As a result, the maximum stray inductance of the LBB for 200-V, 50-kW is achieved to 59 nH in simulation and 58.3 nH in experiment. Besides, when the surge voltage exceeds the tolerance, a snubber capacitor is used in order to limit the surge voltage. In this paper, the design method of the snubber capacitor is also proposed. Concretely, the relationship among snubber capacitance, surge voltage and turn-on loss is derived. As the result, it is confirmed that the surge voltage becomes 231 V when the output current is 310 A by experiment. Thus, the design method of snubber capacitor to suppress the surge voltage is validated.
FULL PAPER LINK ORIGINAL
three-phase to single-phase matrix converter; surge voltage suppression; laminated bus bar; simple AC snubber

sábado, 23 de maio de 2015

Switching Loss Reduction of AC-AC Converter using Three-level Rectifier and Inverter for UPS. Kazuki Yoneda, Hiroki Takahashi and Jun-ichi Itoh Dept. of Electrical, Electronics and Information Engineering Nagaoka University of Technology Nagaoka, Niigata, Japan





Abstract— This paper proposes an AC-AC converter, which consists of T-type three-level rectifier and inverter, for an on-line UPS. The switching loss of the proposed AC-AC converter is drastically reduced because the proposed converter is driven at a very low switching frequency which is six times of input side frequency. The T-type rectifier separates the maximum phasevoltage, medium phase-voltage and minimum phase-voltage from the input voltage. Next the output waveform is built by the T-type inverter from each maximum phase-voltage, middle phasevoltage and minimum phase-voltage. The proposed circuit can achieve not only high efficiency, but also short instantaneous interruption time. Furthermore, the proposed AC-AC converter compensates a voltage dip with changing an operation mode of a rectifier. In this paper, the fundamental operation of the proposed converter is confirmed by simulations and experiments. In addition, the power loss of the proposed converter is compared to a conventional on-line UPS and the efficiency of the proposed converter is 97.1% at rated load in an experiment.

FULL PAPER  LINK ORIGINAL NA WEB
http://itohserver01.nagaokaut.ac.jp/itohlab/paper/2014/141105_peac2014/yoneda.pdf
LINK ALTERNATIVO
https://copy.com/LkWFpaxB26DaKPAI

quarta-feira, 6 de maio de 2015

A Novel Single-Phase Cascaded Multilevel AC-AC Converter Without Commutation Problem Kim, Sang-hun Department of Electrical Engineering Graduate School, Kyungpook National University Daegu, Korea






ABSTRACT
A Novel Single-Phase Cascaded Multilevel AC-AC Converter Without Commutation Problem Kim, Sang-hun Department of Electrical Engineering Graduate School, Kyungpook National University Daegu, Korea (Supervised by Professor Kim, Heung-Geun) Abstract) This paper presents a novel cascaded multilevel PWM ac-ac converter that can solve commutation problem. By cascading the single-phase PWM ac-ac converter that uses basic switching cell structure and coupled inductors, the proposed converter does not need to sense the voltage or current polarity for safe commutation. When many unit-cells are cascaded, the proposed converter has more output voltage levels and can obtain high ac output voltage by using low voltage rating switching devices. By applying phase-shifted PWM technique, the proposed converter can reduce output filter size significantly. A 2 kW prototype converter having four unit-cell structure is built and tested to verify the performance.

Novel Current-Mode AC/AC Converters With High-Frequency AC Link-Daolian Chen-Power Electronics Research Institute, Fuzhou University, Fuzhou






Abstract—A novel circuit-topology family of the current-mode ac/ac converter with high-frequency ac link, based on a Flyback converter, is proposed. These circuit topologies, which can transfer one unregulated sinusoidal voltage with high total harmonic distortion (THD) into another regulated constant-frequency sinusoidal voltage with low THD, are composed of input cycloconverter, high-frequency storage transformer, and output cycloconverter. The circuit-topology family includes single fourquadrant power switch mode, push–pull mode, half-bridge mode, and full-bridge mode circuits. The single four-quadrant power switch mode and push–pull mode converters are suitable for low input voltage fields, but the half-bridge mode and full-bridge mode converters are suitable for high input voltage fields. The operational mode, steady principle, and transient voltage feedback control strategy of the kind of converter are investigated. The output characteristic curve, its relation to internal resistance, and the design criteria for the key circuit parameters are given. The theoretical analysis and the test result of the 500 VA 220 V ± 15% 50 HzAC/220 V 50 HzAC prototype have shown that the converters have advantages such as high-frequency galvanic isolation, simple topology, two-stage power conversion [low frequency alternating current (LFAC)/high frequency alternating current (HFAC)/LFAC], bidirectional power flow, high efficiency, high power density, low THD of the output voltage, strong adaptability to various loads, higher line power factor, low audio,noise, etc.

sábado, 2 de maio de 2015

ESS- Engineering Simulation and Scientific Software


A Engineering Simulation and Scientific Software surgiu com o objetivo de estabelecer um elo entre a produção científica desenvolvida nas universidades e a aplicação deste conhecimento na indústria, trazendo ao mercado o dinamismo e o espírito investigativo do meio científico, além da busca constante pela excelência na qualidade de seus serviços. Criada em 1995, a partir do Laboratório de Simulação Numérica em Mecânica dos Fluidos e Transferência de Calor da UFSC, renomada universidade federal brasileira, a ESSS iniciou suas operações com o desenvolvimento de softwares customizados para diversos setores do Centro de Pesquisas da Petrobras, com o qual realiza até hoje atividades de P&D nas áreas de exploração, produção, refino e distribuição de petróleo e derivados. Atualmente, mais de 300 profissionais de 50 departamentos da Petrobras utilizam as soluções fornecidas pela ESSS e uma média de 200 profissionais da estatal participam anualmente dos treinamentos oferecidos pelo Instituto ESSS de Pesquisa, Desenvolvimento e Educação. No total, a ESSS possui mais de 500 instituições como clientes nos mais diversos segmentos da indústria sul-americana, entre os quais de óleo e gás, aeroespacial, automotivo, metal-mecânico, geração de energia, turbomáquinas, processos químicos e mineração.

ATUAÇÃO INTERNACIONAL Desde que surgiu, a ESSS mantém um crescimento orgânico e vem conquistando importantes prêmios de inovação tecnológica. Além disso, realizou parcerias técnicas e comerciais com empresas globais de Computer Aided Engineering (CAE) e tornou-se o centro de excelência ANSYS no Brasil e na América do Sul. Ao longo dos anos, a ESSS ganhou destaque internacional por oferecer ao mercado soluções completas de modelagem matemática e simulação computacional e expandiu suas instalações para Argentina, Chile, Colômbia, Estados Unidos e PERU.
LINK
http://www.esss.com.br/empresa_conheca_a_esss.php

A 600-W Switched-Capacitor AC–AC Converter for 220 V/110 V and 110 V/220 V Applications-Telles B. Lazzarin, Romero L. Andersen, Guilherme B. Martins, and Ivo Barbi-UNIVERSIDADE FEDERAL DE SANTA CATARINA PROGRAMA DE PÓS-GRADUAÇÃO EM ENGENHARIA ELÉTRICA-BRASIL








Abstract—This letter proposes an ac–ac converter based on the switched-capacitor principle. The new topology is described, ana- lyzed, designed, and tested in the laboratory. The converter char- acteristics at the frequency of the input voltage and at the switching frequency are described herein. The absence of magnetic elements and the stress voltages in all components equal to half the input voltage are the main advantages of the proposed ac–ac converter. In order to demonstrate the performance of this converter a de- sign example and experimental results for a prototype of 600 W, 220 Vrms high-side voltage, 110 Vrms low-side voltage, and switch- ing frequency of 50 kHz are reported herein. The maximum and nominal efficiencies obtained were 95.6%and 90.6%, respectively.

DISSERTAÇÕES DE MESTRADO 2013

ESTUDO DE CONVERSORES A CAPACITORES CHAVEADOS.-Guilherme Brunel Martins
LINK http://www.ivobarbi.com/PDF/dissertacoes/DissertacaoGuilhermeBrunelMartins.pdf

domingo, 26 de abril de 2015

Three-Phase PWM-Switched Autotransformer Voltage-Sag Compensator Based on Phase Angle Analysis Muhamad Mansor and Nasrudin Abd. Rahim








M. Mansor1 N.A. Rahim2
1Department of Electrical Power Engineering, Universiti Tenaga Nasional, Selangor, Malaysia
2UM Power Energy Dedicated Advanced Centre (UMPEDAC), University of Malaya, Kuala Lumpur, Malaysia
E-mail: Muhamadm@uniten.edu.my

ABSTRACT
Many voltage sag compensators have been introduced, including the traditional dynamic voltage restorer (DVR), which requires an energy storage device but is inadequate for compensating deep and long-duration voltage sags. The AC-AC sag compensators introduced next do not require a storage device and they are capable of compensating voltage sags. This type of compensator needs an AC-AC converter to regulate the output voltage. Presented in this paper is a three-phase PWM-switched autotransformer voltage sag compensator based on an AC-AC converter that uses a proposed detection technique and PWM voltage control as a controller. Its effectiveness and capability in instantly detecting and compensating voltage sags were verified via MATLAB/Simulink simulations and further investigated through a laboratory prototype developed with a TMS320F2812 DSP as the main controller.
LINK ORIGINAL WEB
http://www.jpe.or.kr/archives/view_articles.asp?seq=585
LINK DIRECT PAPER
http://manuscript.jpe.or.kr/ltkPSWeb/pub/pubfpfile.aspx?ppseq=585

LINK ALTERNATIVO
https://copy.com/wp6zbJtEnF99Xoxw

sexta-feira, 24 de abril de 2015

Research on a GaN HEMT On-Board Charger for Electric Vehicles -Guoen Cao-Department of Electronic Systems Engineering Hanyang University Graduate School






Research on a GaN HEMT On-Board Charger for Electric Vehicles Guoen Cao
 Hanyang University Graduate School Department of Electronic Systems Engineering

 ABSTRACT

Research on a GaN HEMT On-Board Charger for Electric Vehicles Guoen Cao Dept. of Electronic Systems Engineering The Graduate School Hanyang University With an accelerating global energy crisis and deteriorating environmental problems, electric vehicle (EV) technologies have attracted growing interest due to their reduced fuel usage and greenhouse emissions. The battery charger plays a critical role for the acceptance and development of EVs. Because a battery is generally used as the main power source, a high conversion efficiency, high power density, and lightweight on-board-charger (OBC) is needed in order to maximize the energy utilization. Gallium nitride based high electron-mobility transistors (GaN HEMTs) are potential candidates as next-generation power switching devices due to the enormous potential use in the applications of high frequency, high temperature, and high output power, in particular of battery charger applications. Although much progress has been achieved in the development of GaN HEMTs, a few important issues such as current collapse effects should be evaluated before wide deployment is possible. Since evaluating performance in power semiconductors and selecting the optimal topologies are important steps in the design and development of power electronics circuits, this thesis is concerned with the performance evaluation of the new GaN HEMTs and the design of an isolated OBC that uses GaN HEMTs to achieve high efficiency for future applications in EVs.