sábado, 14 de abril de 2012
A Review of Multilevel Inverter Based Active Power Filter Madhukar Waware and Pramod Agarwal
A Review of Multilevel Inverter Based Active Power Filter
Madhukar Waware and Pramod Agarwal
Abstract—Use of nonlinear loads at high voltages has increased tremendously in industry. These non-linear loads distort power quality by generating harmonics. Conventional active filters have limitations in high power high voltage systems. Use of multilevel inverter in active filters effectively reduces harmonics in high voltage systems eliminating need of high cost and bulky transformer. This paper presents the state of art of different topologies of multilevel inverter (MLI) used for active power filters (APF), the different control techniques and advanced modulation methods. It is aimed to provide a broad perspective on the status of MLI based APF technology to researchers and application engineers dealing with power quality issues in high voltage systems.
FULL PAPER HERE :http://www.ijcee.org/papers/314-E336.pdf
quarta-feira, 11 de abril de 2012
RTA UNICA FABRICANTE DE AMERICA LATINA Filtro Ativo de Harmônicas SAO PAULO BRASIL
RTA REDE DE TECNOLOGIA AVANÇADA :http://www.rta.com.br
FILTERON
Filtro Ativo de Harmônicas
Capacidade: 25 até 800 amperes, paralelis de tensão 220/380/480/690 VCADisponível em média tensão até 13800Volts.
Configuração: 3 fases – 4 fios
Frequência: 50/60hz.
Customizações em diferentes montagens mecânicas e graus de proteção.
Interface Modbus e LCD (opcional). Compativel com a IEEE519
Funções
FILTERON é um conversor de potência em estado sólido, que proporciona as seguintes funções:
— Elimina a corrente harmônica em sistemas com carga não-linear.
— Compensação do fator de potência.
— Resistor virtual de amortecimento para prevenir a destruição por ressonância harmônica.
FILTERON é como um gerador de corrente reativa, especialmente quando são necessárias ao sistema. As harmônicas produzidas pelo FILTERON cancelam as harmônicas geradas pela carga não-linear, bem como a corrente injetada com o deslocamento capacitivo necessária a correção do fator de potência total, incluindo o fator de deslocamento.
Após o cancelamento das correntes harmônicas, seguem algumas vantagens óbvias:
(1) Prevenir a destruição por ressonância da corrente harmônica;
(2) Diminuição significativa da distorção da forma de onda da tensão;
(3) Diminuição da queda de tensão em transformadores e cabos;
(4) Redução da variação de temperatura em transformadores e cabos;
(5) Aumento do fator de potência, podendo chegar a unitário
(6)Aumento da vida útil das cargas
(7)Eficiência energética com redução das perdas por aquecimento
(8) Redução dos custos de manutenção.
segunda-feira, 9 de abril de 2012
Power Quality Enhancement of Three-Phase Front-End Rectifier of UPS System Using Current Injection Technique
Power Quality Enhancement of Three-Phase
Front-End Rectifier of UPS System Using
Current Injection Technique
Gunwant A. Dhomane and Hiralal M. Suryawanshi
Visvesvaraya National Institute of Technology, Nagpur, India
Summary: Power Quality, in terms of power factor and harmonics, is greatly hampered by a threephase
rectifier used as a front-end ac-to-dc converter in many systems including a UPS. This paper
presents the high power factor operation of the converter with reduced total harmonic distortion up
to 4%. The power quality up gradation is due to high-frequency current injection, at the input of the
front-end rectifier. A small filter is required at the output for filtering the high-frequency content.
Sinusoidal PWM technique is used for controlling the output voltage. DSP is used for generating
the desired gate pulses. The converter has high efficiency, low EMI emissions, high power packing
density and suitable for UPS system. A Simulation and experimentation is carried out on a 3 kW
converter and experimental results are in good agreement with simulation results.
FULL PAPER HERE:http://www.epqu.agh.edu.pl/archives/journal/v14i2/v14i2_04.pdf
A Modified Harmonics Reduction Technique for a Three-Phase Controlled Converter
A Modified Harmonics Reduction Technique
for a Three-Phase Controlled Converter
Ali M. Eltamaly
Abstract—Three-phase controlled converters have many applications
especially in adjustable speed drives and renewable energy.
A three-phase controlled converter is a good option in these applications
due to its low cost, simplicity, and maintainability with
respect to other solutions like a full-bridge insulated gate bipolar
transistor converter or a Vienna rectifier. Line current harmonics
in this converter is very high; therefore, a harmonics reduction
technique is needed to remedy the problem. In this paper, an
improved injection current technique is introduced to reduce line
current harmonics. The optimal amplitude and phase angle of
the injection current for different loads and firing angles have
been mathematically determined. Simulation for this technique
has been performed by using the PSIM simulation program. An
experimental prototype has been built to verify the mathematical
and simulation results. The simulation and experimental results
show a sensitive variation in the total harmonic distortion of
the line current for the amplitude and angle of injection current
variations. The simulation and experimental results prove the
superiority of this technique in mitigating the requirements for
harmonics standards.
FULLPAPER HERE:http://repository.ksu.edu.sa/jspui/bitstream/123456789/6648/1/Modified%20Harmonics%20Reduction%20Technique%20for%20a%20Three-Phase%20Controlled%20Converter.pdf
LINK2:http://www.mediafire.com/?96w252ckdl10953
quarta-feira, 28 de março de 2012
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
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
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
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