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”

segunda-feira, 26 de março de 2012

Emprededurismo en ciencia y tecnología. Ricardo Alcázar, director Cámara de Comercio de Lima


Enviado por memontoyaz em 25/03/2012

Emprededurismo en ciencia y tecnología
Ricardo Alcázar, director Cámara de Comercio de Lima
entrevistado por Modesto Montoya
en Encuentro con la Ciencia
Programa de Radio San Borja, los domingos a las 10:00 am

sexta-feira, 23 de março de 2012

Filtros ativos paralelos para compensação dinâmica de problemas de corrente em sistemas monofásicos e trifásicos

Este artigo apresenta resultados experimentais de um Filtro Ativo Paralelo Trifásico a 4 fios e de um Filtro Ativo Paralelo Monofásico. O filtro ativo trifásico tem a capacidade de compensar harmônicos de corrente, fator de potência e desequilíbrios de corrente.

Já o filtro ativo monofásico compensa harmônicos de corrente e fator de potência. Ambos os filtros têm o sistema de controle baseado na teoria da potência instantânea (Teoria p-q), que foi implementado num DSP, e utilizam inversores a dois níveis do tipo fonte de tensão com controle de corrente. Resultados experimentais dos filtros ativos mencionados são apresentados.

Para ver o artigo completo, acesse o seguinte endereço:
http://repositorium.sdum.uminho.pt/bitstream/1822/7658/3/XCLEE-07_FAP_MONO_TRI.pdf
FONTE ORIGINAL:http://qualidadedaenergia.blogspot.com.br/

quinta-feira, 22 de março de 2012

FILTER DESIGN FOR GRID CONNECTED PV INVERTERS

FILTER DESIGN FOR GRID CONNECTED PV INVERTERS
Hyosung Kim Kyoung-Hwan Kim
Kongju National University KACO Korea Inc.
School of Electrical Electronics Engineering 1st Floor, Dongbang Rental Bldg
275, Budae, Cheonan, Chungnam, 330-717 Korea 333-1, Sangdaeeon, Jungwon, Seongnam, Korea
e-mail: hyoskim@kongju.ac.kr e-mail: paul.kim@kacokorea.com

Abstract-This paper proposes filter design guideline for
single-phase grid-connected PV inverters. By analyzing the
instantaneous voltage applied on the filter inductor, the
switching ripple current through the filter inductor is
precisely calculated. Therefore, filter inductance can be
designed accurately which guaranties the switching ripple
current under the target value. Proposed filter design
method is verified by experiment.
FULL PAPER: http://www.mediafire.com/?8co1ka9so395tcr

A Harmonic Circulation Current Reduction Method for Parallel Operation of UPS with a Three-Phase PWM Inverter



A Harmonic Circulation Current Reduction Method for Parallel
Operation of UPS with a Three-Phase PWM Inverter
Kyung-Hwan Kim†, Wook-Dong Kim* and Dong-Suk Hyun**
†*EHWA Technologies and Information, Seoul, Korea
**Dept. of Electrical Eng., Hanyang University, Seoul, Korea



ABSTRACT
In a parallel operation of UPS, there are two types of circulating currents between UPS. One is the low order circulating
current with a fundamental frequency caused by the amplitude and phase differences of UPS output voltages, and the other
is the harmonic circulating current with PWM switching frequency caused by non-synchronized PWM waveforms among
UPS. The elimination of the low order circulating current is essential for optimal load sharing in parallel operations of UPS,
which can be accomplished by the phase and magnitude control at each UPS. The harmonic circulating current may cause
troubles and deteriorate in performance of the controller for optimal load sharing in parallel operation of UPS. This paper
presents a PWM synchronizing method to eliminate the harmonic circulation current in parallel operation of UPS. The
effectiveness of the proposed scheme has been investigated and verified through experiments by a 50kVA UPS.

FULL PAPER HERE:
http://www.mediafire.com/?d4zu28a1f8cm9m2