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.

POWER ELECTRONICS M.D. SINGH - K.B. KHANCHANDANI

LINK DEMO BOOK GOOGLE:
http://books.google.co.in/books?id=0_D6gfUHjcEC&lpg=PP1&hl=pt-BR&pg=PP1#v=onepage&q&f=false
LINK DEMO BOOK  google PDF
https://copy.com/pb0Jh0TNRfHk4nZ0

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

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

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.

CIRCUITOS ELECTRÓNICOS Tema: Factor de rizado Docente: Dr. FERNANDO LÓPEZ ARAMBURÚ UNI UNIVERSIDAD NACIONAL DE INGENIERIA LIMA PERÚ

A VOLTAGE SAG SUPPORTER UTILIZING A PWM-SWITCHED AUTOTRANSFORMER-Thesis(doctoral)-- Georgia Institute of Technology : Electrical & Computer Engineering 2004-Dong-Myung Lee

 1.1 Background 

A power distribution system is similar to a vast network of rivers. It is important to remove any system faults so that the rest of the power distribution service is not interrupted or damaged. When a fault occurs somewhere in a power distribution system, the voltage is affected throughout the power system. Among various power quality problems, the majority of events are associated with either a voltage sag or a voltage swell, and they often cause serious power interruptions. A voltage sag condition implies that the voltage on one or more phases drops below the specified tolerance for a short period of time. A voltage swell condition occurs when the voltage of one or more phases rises above the specified tolerance for a short period of time. The causes of voltage sags and swells are associated with faults within the power distribution system. Users located a close distance to the fault experience voltage sags much greater in magnitude and duration than users located farther away, and as the electrical system recovers after removing the fault, voltage swells are produced throughout the system for short periods of time. Often all users who are served by the power distribution system have power interruptions during a fault because of the effects of a voltage sag or voltage swell produced in the system by the fault. The objective of this research is to develop a novel voltage control scheme that can compensate for voltage sag and swell conditions in three-phase power systems. Power systems supply power for a wide variety of different user applications, and sensitivity to voltage sags and swells varies widely for different applications. Some applications such as automated manufacturing processes are more sensitive to voltage sags and swells than other applications. For sensitive loads, even a voltage sag of short duration can cause serious problems in the manufacturing process. Normally, a voltage interruption triggers a protection device, which causes the entire branch of the system to shut down.

LINK PART OF THE THESIS:
https://copy.com/h2Lcmcqbsr7fYCwo

LINKS PAPERS IEEE

A voltage sag supporter utilizing a PWM-switched autotransformer
Dong-Myung Lee ; Habetler, T.G. ; Harley, R.G. ; Rostron, J. ; Keister, T. Power Electronics Specialists Conference, 2004. PESC 04. 2004 IEEE 35th Annual Volume: 6 DOI: 10.1109/PESC.2004.1354751 Publication Year: 2004 , Page(s): 4244 - 4250 Vol.6 Cited by: Papers (5) IEEE Conference Publications

A Voltage Sag Supporter Utilizing a PWM-Switched Autotransformer
Dong-Myung Lee ; Habetler, T.G. ; Harley, R.G. ; Keister, T.L. ; Rostron, J.R. Power Electronics, IEEE Transactions on
Volume: 22 , Issue: 2
DOI: 10.1109/TPEL.2006.890004
Publication Year: 2007 , Page(s): 626 - 635
Cited by:  Papers (28)
IEEE Journals & Magazines

Lecture - 27 Construction of a MOSFET

Lecture Series on Electronics For Analog Signal Processing I by Prof.K.Radhakrishna Rao, Department of Electrical Engineering,IIT Madras. For more details on NPTEL visit http://nptel.iitm.ac.in