AUTOR DO BLOG ENG.ARMANDO CAVERO MIRANDA SÃO PAULO BRASIL

"OBRIGADO DEUS PELA VIDA,PELA MINHA FAMILIA,PELO TRABALHO,PELO PÃO DE CADA DIA,PROTEGENOS DO MAL"

"OBRIGADO DEUS PELA VIDA,PELA MINHA FAMILIA,PELO TRABALHO,PELO PÃO DE CADA DIA,PROTEGENOS  DO MAL"

“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”

https://picasion.com/
https://picasion.com/

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.

sexta-feira, 17 de abril de 2015

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

terça-feira, 14 de abril de 2015