“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


AUTOR DO BLOG ENG. ARMANDO CAVERO MIRANDA SAO PAULO BRASIL

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.

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

domingo, 12 de abril de 2015

Lecture 11: The energy and momentum of the Einstein equations- Лекция 11: Энергия, импульс и уравнения Эйнштейна

Обсуждаются свойства уравнений Эйнштейна. Обсуждается роль тензора энергии-импульса в общей теории относительности. Разбирается простейшие пример скалярного поля материи. Обсуждаются уравнения для слабого гравитационного поля как линейное приближение уравнений Эйнштейна. Лекция и тесты в НОУ "ИНТУИТ" http://www.intuit.ru/studies/courses/...

EL CAMPO ELECTROMAGNETICO EN EL LENGUAJE DE LAS ECUACIONES DIFERENCIALES-Лекция 7: Электромагнитное поле на языке дифференциальных форм. Действие

Demuestra la conveniencia de registrar las ecuaciones básicas de la electrodinámica en el lenguaje de las formas diferenciales. Describe la forma potencial, el campo electromagnético, la densidad de corriente.

sexta-feira, 3 de abril de 2015

HOW TO USE A multimeter for ADVANCED measurements: Part 2 - Current Probes / clamps / transducers

EXCELLENT VIDEO BLOG MARTIN LORTON´S

Curso de Formação de Eletricista BT e MT - Ferramenta Loadbuster - Cuiabá - MT.


O Loadbuster é usado em conjunto com o bastão de manobra, ou seja, acoplado na extremidade do mesmo, de modo que possibilite que cada chave seccionadora e/ou chave fusível, transforme em ponto de interrupção do sistema de distribuição e com isso minimize o tempo de interrupção, afetando um menor número de consumidores.

quinta-feira, 2 de abril de 2015

VOLDEK , POPOV - LA MAQUINA DE CORRIENTE ALTERNA



LINK ORIGINAL WEB
http://www.vixri.ru/d3/Voldek A.I. _Elektricheskie mashiny PEREMENNOGO toka.pdf

Design and control of unified power conversion system for EV electric vehicle -Park,SangHoon Dept. of Mechatronics Engineering-Sungkyunkwan University






Design and control of unified power conversion system for EV
ABSTRACT
Most developed countries that produce vehicles and automobile companies invest in lots of budgets for developing electric vehicle to reduce the use of fossil fuel. Particularly, as the battery technology has been made rapid progress, electric vehicles are able to operate with only battery system. In this context, battery charger connected with grid is required to charge the batteries attached with vehicles. Battery charger charges the battery bank through using the electrical energy of grid, and the operation is similar with that fossil fuel is injected into the gas tank of an internal-combustion engine. This system requires input power factor controller and energy conversion system for charging the battery bank, and the system generally consists of diode rectifier and DC/DC converter or single stage AC/DC PWM converter. In the case of the charger that consists of diode rectifier and DC/DC converter, based on the voltage level of battery, the battery is charged through using buck type or boost type DC/DC converter, and the input power factor is controlled as well. On the other hand, AC/DC PWM converter contains single stage circuit that consists of power semi-conductor switching devices instead of diode rectifier, and the converter charges battery and controls input power factor. Moreover, the structures of energy conversion system to control motor are classified into two types. The first type is that the voltage and capacity of battery bank is bulky. In this case, the battery bank is employed as the input of inverter. The inverter supplies energy for operating to motor and transports free-wheeling energy generated when vehicle brakes suddenly to the battery bank through simple rectifying operation. The second type is that the voltage and capacity of the battery bank is comparably low. When the vehicle is operating, the Bi-directional DC/DC converter boosts the battery energy until the voltage is same as that of inverter DC-link. On the other hand, when the vehicle is braking, the free-wheeling energy is charged into the battery bank through the Bi-directional DC/DC converter.

In this paper, battery charger used for electric vehicle as an energy conversion system, Bi-directional DC/DC converter, and three-phase voltage source inverter were designed. The inverter performs the vector control of interior synchronous permanent magnet motor for electric vehicle. Also, depending on the driving mode, simulation was performed through using the designed energy conversion system. The battery charger charges four 12[V] series connected lead battery bank with single commercial power, and the charger was designed based on AC/DC PWM buck converter. The capacity of the employed battery bank is 48[V]/100[Ah], and the battery bank was charged in constant current control condition with 0.2[C-rate], 20[A]. The Bi-directional DC/DC converter was designed based on three-phase interleaved type buck-boost DC/DC converter. The designed converter controls the output voltage constantly as 250[V] in operating condition, and the inductor current of each phase was controlled by the designed converter to have same average current value.


Particularly, the DC-link voltage of inverter is controlled in 230~270[V] range by the instantaneous boost and buck operations of Bi-directional DC/DC converter in free-wheeling mode. Due to the operational characteristic of the Bi-directional DC/DC converter, the DC-link voltage of the inverter is able to be stable, and the system shows better performance than vector controlled system since DC-link voltage of the inverter is controlled in definite range when free-wheeling mode is turned into driving mode. Previously mentioned, 1.2[kW] battery charger was designed for the 0.2[C-rate] constant current and 50.7[V] constant voltage control of 48[V]/100[Ah] battery bank, and 4[kW] Bi-directional DC/DC converter for boosting the charged energy of battery bank and three-phase voltage source inverter were designed. The designed energy conversion systems verified the validity of results through presenting the experimental results depending on the driving modes of electric vehicle.

LINK
https://copy.com/8KlrtiJczM6sz0lm

quarta-feira, 1 de abril de 2015

I.A.KVASNIKOV. / Introduction to the theory of electrical conductivity and superconductivity-И.А.КВАСНИКОВ. / ВВЕДЕНИЕ В ТЕОРИЮ ЭЛЕКТРОПРОВОДНОСТИ И СВЕРХПРОВОДИМОСТИ





LINK ORIGINAL
http://www.vixri.ru/?p=3525
LINK DIRECTO
http://www.vixri.com/d/Kvasnikov%20I.A.%20_Vvedenie%20v%20teoriju%20elektroprovodnosti%20i%20sverxprovodimosti.pdf

SISTEMA FOTOVOLTAICO INTERLIGADO À REDE ELÉTRICA COM CONTROLE DE FLUXO DE POTÊNCIA FEITO POR UM CONVERSOR CC-CC ISOLADO-SAMUEL SOARES QUEIROZ-Engenharia Elétrica-Universidade Federal do Ceará-BRASIL






SISTEMA FOTOVOLTAICO INTERLIGADO À REDE ELÉTRICA COM
CONTROLE DE FLUXO DE POTÊNCIA FEITO POR UM CONVERSOR CC-CC
ISOLADO

SAMUEL SOARES QUEIROZ

Monografia apresentada para obtenção dos
créditos da disciplina Trabalho de Conclusão
de Curso do Centro de Tecnologia da
Universidade Federal do Ceará, como requisito
parcial à obtenção do título de Graduado em
Engenharia Elétrica. Área de concentração:
Eletrônica de Potência e Acionamentos.
Orientador: Prof. Dr. René Pastor Torrico
Bascopé

FORTALEZA
2014

LINK ORIGINAL MONOGRAFIA COMPLETA
http://www.dee.ufc.br/anexos/TCCs/2014.1/SAMUEL%20SOARES%20QUEIROZ.pdf