“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

segunda-feira, 26 de setembro de 2016

Thermography in UPS Maintenance - Jason Marriott Managing Director, Power Protect Pty Ltd


Thermography in UPS Maintenance

 Not so long ago the practice of thermography was limited to scientific applications primarily due to the cost and difficulty in setting up and using the equipment. These days the cost of thermal cameras has come down sufficiently for them to be a standard part of the service technician's toolkit. Power Protect purchased our first thermal camera in 2012 and the benefits to our service team were instantly obvious. Shortly after we made the thermal camera a standard item supplied to each and every one of our service techs. While having a thermal camera is a good first step, it is just as important to have the training in how to collect and interpret the thermal images that we use for the basis of our service recommendations. This has led us to a combination of in-house training, accredited training through the University of Melbourne, and certification with the Australian Institute of Non-Destructive Testing (AINDT) Armed with the right tools and training for the job, we've found many issues that could have gone unnoticed if not for our use of the thermal camera on each and every UPS maintenance visit. Here we have a collection of some of the images that have been captured.

As part of a commissioning on a new 80kVA UPS, the system was subjected to a discharge test to confirm the batteries were performing in line with the manufacturers specifications. While the batteries performed as required a scan of the batteries during the discharge test identified that the positive post on this block had a higher temperature than others in the string. The battery itself did not show any signs of an issue with the float and discharge block voltage consistent with those around it, however the post temperature clearly indicates that the internal post connection is a higher resistance than it should be while under load. After being presented with this image the manufacturer immediately authorised a warranty replacement, and just like preventative maintenance should the problem was fixed before it became a problem.


This output filter capacitor is from a smaller UPS and features 'spade' style crimped connections. These are notorious for spreading apart leaving a poor connection. While not warm enough to leave a visible mark on the crimp's insulation, the elevated temperature would at best shorten the service life of the capacitor and at worst fail completely potentially damaging the UPS or customers equipment.


Here is another spade terminal, however on a battery this time. UPS batteries systems are made up of a string of batteries in series. The inherent weakness is that an open circuit failure at any point along the string will render the entire string out of service. Being able to see the poor connection on this battery link allowed us to replace it straight away as part of the preventative maintenance.


Finally, this image shows a loose termination on an external maintenance bypass switch. The bypass switch in this image is for the 'A' UPS on a 2N (or A/B redundant) system. This means that a failure of the 'B' system would result in a doubling of the load on the A UPS and its bypass switch. With the temperature rise shown for 50% of the site load it is unlikely this would have survived long if required to support 100% of the load. LINK ORIGINAL
https://www.linkedin.com/pulse/thermography-ups-maintenance-jason-marriott

domingo, 25 de setembro de 2016

CONVERSOR DE ALTO GANHO ASSOCIADO A UM INVERSOR PARA APLICAÇÃO EM SISTEMA AUTÔNOMO DE ENERGIA ELÉTRICA -Engo . Luiz Daniel S. Bezerra-Pós-Graduação em Engenharia Elétrica da Universidade Federal do Ceará.-BRASIL




RESUMO
Resumo da dissertação apresentada à Universidade Federal do Ceará como parte dos requisitos para obtenção do Grau de Mestre em Engenharia Elétrica.
CONVERSOR CC-CA PARA APLICAÇÃO EM SISTEMAS AUTÔNOMOS DE ENERGIA ELÉTRICA Engo . LUIZ DANIEL S. BEZERRA
 O estudo e o desenvolvimento de novas topologias ou associações destas com o intuito de aplicar em sistemas autônomos de fornecimento de energia elétrica são os principais motivadores deste trabalho. O projeto consiste da associação de dois conversores, um conversor elevador de alto ganho baseado na célula de comutação de três estados, cujo papel é elevar a tensão das baterias a um valor de 400Vcc, formando assim um barramento de tensão contínua, e um inversor monofásico do tipo ponte-completa com um filtro LC, utilizando modulação do tipo bipolar para obter a tensão senoidal semelhante à da rede elétrica. O controle do conversor elevador é realizado através de uma malha de corrente e de tensão, ambas analógicas, porém com uma parte da malha de tensão sendo realizada internamente em um dsPIC, e o controle do inversor é totalmente realizado através deste dsPIC (modulador digital e controlador digital), utilizando os principios do controle discreto. Este sistema é capaz de converter 48Vcc proveniente de baterias em 220Vac e 60Hz, com eficiência igual ou superior a 85% com uma ampla faixa de carregamento. Cada estágio tem seu estudo teórico desenvolvido, além da introdução de uma metodologia para obtenção de um modelo reduzido do conversor elevador de alto ganho, e ao final, após as especificações e dimensionamentos são mostrados os resultados experimentais do protótipo do projeto. O sistema foi testado nas diversas situações que podem ser encontradas no dia-a-dia, como partida de carga não linear, por exemplo. Número de páginas: 214. Palavras-Chave: Eletrônica de Potência, Fonte Ininterrupta de Energia, Elevador de Alto- Ganho, Célula de Três estados, Controle Discreto, Sistema Autônomo.

LINK
http://www.mediafire.com/download/red7tr12zyhx99c/Dissertacao_Luiz_Daniel_S_Bezerra-_PRINCIPAL_-_v07-FINAL.pdf

quinta-feira, 22 de setembro de 2016

Power Electronics and Control Techniques for Maximum Energy Harvesting in Photovoltaic Systems Authors: Nicola Femia, Giovanni Petrone, Giovanni Spagnuolo AND Massimo Vitelli


Power Electronics and Control Techniques for Maximum Energy Harvesting in Photovoltaic Systems Authors: Nicola Femia, Giovanni Petrone, Giovanni Spagnuolo & Massimo Vitelli

LINK ORIGINAL
https://issuu.com/robertocteixeira/docs/power_electronics_and_control_techn/1

Convertidores AC/DC JUAN AGUILAR PEÑA ,FRANCISCO MARTINEZ HERNÁNDEZ

Presentamos un extenso resumen de los tres tomos que en su día fueron publicados dentro de la colección de Apuntes 1995/1996, de la Universidad de Jaén, cuyos títulos fueron “Electrónica de Potencia: Convertidores DC-DC”, “Electrónica de Potencia: Convertidores DC-AC”, “Electrónica de Potencia: Convertidores AC -DC”, realizados en colaboración con alumnos de Ingeniería Técnica, como motivo de su trabajo fin de carrera. Se pretendía en su día cubrir las necesidades docentes de una materia tan importante como los Convertidores Estáticos dentro de la Electrónica de Potencia, en su día asignatura troncal del plan de estudios de Ingeniería Técnica y en la actualidad materia troncal en el Grado de Ingeniería Electrónica Industrial.
LINK ORIGINAL EN LA WEB
https://issuu.com/jaguilarpena/docs/convertidores_acdc/1

Advanced DC-AC Inverters - Applications in Renewable Energy - Fang Lin Luo AND Hang Ye


LINK ORIGINAL
https://issuu.com/robertocteixeira/docs/advanced_dc-ac_inverters_-_applicat/1

quarta-feira, 21 de setembro de 2016

POTENCIA FÓRUM ETAPA SÃO PAULO Data:18 DE OUTUBRO Horário:08H-18H


ETAPA SÃO PAULO 2016 PROGRAMAÇÃO DO CONGRESSO (PRELIMINAR) Horários a serem informados oportunamente. Novas palestras serão incluídas em breve.
Requisitos da norma NBR 5410 que não podem faltar em uma instalação elétrica Hilton Moreno - professor, consultor do Procobre, diretor da Revista Potência
 Como elaborar orçamentos de instalações elétricas residenciais Everton Moraes - professor, diretor do blog Sala de Elétrica
A importância da análise de risco para o profissional eletricista Edson Martinho - consultor, diretor da Abracopel Sistema de conexão elétrica a mola: uma solução moderna, segura e econômica Especialista da WAGO

Novas canaletas de alumínio que inovam qualquer sistema e atendem completamente a NBR 5410 Especialista da DUTOTEC Instalação de cabos elétricos conforme a NBR 5410 Hilton Moreno - consultor da COBRECOM
Segurança nas instalações elétricas com aplicação de cabos não halogenados Especialista da GENERAL CABLE
 Apresentação técnica AltoQI sobre softwares para instalações elétricas Especialista da AltoQI As facilidades para especificar o material de infra-elétrica com o uso da NBR 15701 Especialista da DAISA

Encerramento / Sorteio de brindes

LINK ORIGINAL DA INFORMAÇÃO
http://revistapotencia.com.br/forum.html


terça-feira, 20 de setembro de 2016

Inversor de Frequência Weg CFW 10 - Os principais parâmetros que você precisa conhecer



Publicado em 15 de set de 2016 http://page.saladaeletrica.com.br/ebo...
- Você já deve ter ouvido falar do inversor de frequência correto? Mas efetivamente qual a função do inversor e como configurar o inversor de frequência? Neste vídeo a minha intenção foi realmente trazer a você o que é realmente necessário e importante quando o assunto é parametrização de inversor de frequência Falamos basicamente sobre a parte de controle de rampa de aceleração e rampa de desaceleração do motor, definição de corrente nominal do motor elétrico, frenagem em CC, ajuste de frequência máxima e mínima. Claro que o inversor de frequência possui muito mais configurações e parâmetros do que os que falamos na aula de hoje mas tenha certeza que, no mínimo, o que você vai configurar nele são estes que comentei na aula.

 Obs: Baixe nosso ebook sobre Grau de Proteção de Motores Elétricos neste link: http://page.saladaeletrica.com.br/ebo... Para exemplo utilizamos o inversor CFW10 da WEG, o mais interessante é que, o que eu falei para você servirá também para outros modelos e marcas, basta você encontrar qual o parâmetro para cada fabricante, nos modelos WEG você encontrará no CFW08, CFW09 as mesmas configurações e operação. Espero que tenha gostado deste vídeo Um forte abraço Everton Moraes.

O que significa proteção IP20, IP65 e IP67 ?

Uma dúvida comum, principalmente no caso de equipamentos elétricos é: será que eu posso molhar essa coisa?
Para poder responder a essa pergunta foi instituído a classificação IP. Além disso, o código permite determinar padrões internacionais de proteção e de testes, de forma que os fabricantes possam se adequar e os consumidores possam escolher corretamente o tipo de proteção que desejam.
 Código de Proteção IP 
 O código IP (do inglês Ingress Protection Rate) – ou Proteção Contra Infiltração – também interpretado como Taxa de Proteção Internacional, classifica os níveis de proteção contra intrusões de objetos sólidos (inclusive mãos, dedos e partes do corpo humano), poeira, contato acidental, e também infiltrações de materiais líquidos.

 Por exemplo, uma tomada elétrica classificada como IP22 é protegida contra inserção de dedos e não será danificada nem se tornará insegura quando instalada na posição vertical, mesmo se exposta a gotejamento de até 10 minutos. IP22 é a taxa mínima tipicamente requerida por acessórios elétricos de uso interno, comercial e residencial.

 No código, o primeiros dígito indica o nível de proteção do encapsulamento contra acesso às partes perigosas (por exemplo condutores elétricos e partes móveis) e o ingresso de objetos estranhos sólidos. O segundo dígito indica o nível de proteção do encapsulamento contra acesso de líquidos externos, conforme abaixo:
SOLIDOS
NívelTamanho do objeto protegidoProteção efetiva contra
0Sem proteção contra o ingresso de objetos
1>50 mmQualquer superfície grande do corpo, tal como as costas das mãos, mas sem proteção contra contato intencional de partes de outras partes do corpo
2>12.5 mmDedos ou objetos de tamanho similar
3>2.5 mmFerramentas, Fios grossos, etc.
4>1 mmA maioria dos fios, chaves de fenda, etcetc.
5PoeiraIngresso parcial de poeira, contudo mesmo um eventual ingresso de poeira não interferirá na operação do equipamento; A proteção contra contato é total.
6Proteção total contra pó, poeira e contato.
LIQUIDOS

NívelProteção contraTestado comDetalhes  
0Não protegido
1GotejamentoGotejamento de água (gotas na vertical) não deverão danificar o equipamento.Duração do teste: 10 minutosGotejamento equivalente a 1mm de água por minuto
2Gotejamento com inclinação de até 15°Gotejamento de água (gotas na vertical) não deverão danificar o equipamento, mesmo se este estiver inclinado 15° de sua posição normal.Duração do teste: 10 minutosGotejamento equivalente a 3mm de água por minuto
3Espirro / EsguichoEspirro, esguicho ou spray de água em qualquer ângulo até 60° da vertical não deverão danificar o equipamento.Duração do teste: 5 minutosVolume de água: 0.7 litros por minutoPressão: 80–100 kPa
4Jato leveJato de água contra o encapsulamento de qualquer direção não deverá danificar o equipamento.Duração do teste: 5 minutosVolume de água: 10 litros por minutoPressão: 80–100 kPa
5Jato forteJato projetado por um bico (6.3 mm) contra o encapsulamento de qualquer direção não deverá danificar o equipamento.Duração do teste: mínimo 3 minutosVolume de água: 12.5 litros por minutoPressão: 30 kPa a uma distância de 3 m
6Jato de pressãoJato de pressão por um bico (12.5 mm) contra o encapsulamento de qualquer direção não deverá danificar o equipamento.Duração do teste: mínimo 3 minutosVolume de água: 100 litros por minutoPressão: 100 kPa a uma distância de 3 m
7Imersão até1 mIngresso de água em quantidade suficiente para produzir danos não deve ser possível nas condições de teste especificadas.Duração do teste: 30 minutosImersão em 1 metro medida na base do dispositivo, desde que o topo fique ao menos 15 cm imerso.
8Imersão superior a 1 mO equipamento é projetado para imersão contínua sob as condições especificadas. Normalmente, esse equipamento é hermeticamente selado (blindado).Entretanto, em certos equipamentos, ainda que haja ingresso de água, a quantidade não é suficiente para causar danos.Duração do teste: Imersão continua
LINK ORIGINAL EN LA WEB
https://cidadeled.wordpress.com/2014/02/03/o-que-significa-protecao-ip20-ip65-e-ip67/

Experiencia KOLFF / ABB Expo Hospitalaria


ON SEPTIEMBRE 15, 2016
KOLFF ha concluido su participación en la Séptima versión de la Expo Hospitalaria, la cual se desarrolló entre los días 06 y 08 del presente mes en el centro de eventos Centro Parque. En esta ocasión hemos contado con el apoyo y participación de la empresa ABB en todo lo relacionado a tecnología de UPS. Unidos concretamos reuniones comerciales con los profesionales a cargo de los departamentos de prevención y seguridad de grandes centros hospitalarios del país.
FUENTE ORIGINAL DE LA NOTICIA
http://kolff-e.com/2016/09/15/experiencia-kolffabb-expo-hospitalaria/

segunda-feira, 19 de setembro de 2016

High-Efficiency Three-Phase Current Source Rectifier Using SiC Devices and Delta-Type Topology Ben Guo University of Tennessee





High-Efficiency Three-Phase Current Source Rectifier Using SiC Devices and Delta-Type Topology 
A Dissertation Presented for the Doctor of Philosophy 
Degree The University of Tennessee, Knoxville
High-Efficiency Three-Phase Current
Source Rectifier Using SiC Devices and
Delta-Type Topology
A Dissertation Presented for the
Doctor of Philosophy
Degree
The University of Tennessee, Knoxville
Ben Guo

December 2014
Abstract 
In this dissertation, the benefits of the three-phase current source rectifier (CSR) in high power rectifier, data center power supply and dc fast charger for electric vehicles (EV) will be evaluated, and new techniques will be proposed to increase the power efficiency of CSRs. A new topology, referred as Delta-type Current Source Rectifier (DCSR), is proposed and implemented to reduce the conduction loss by up to 20%. By connecting the three legs in a delta type on ac input side, the dc-link current in DCSR can be shared by two legs at the same time. To increase the switching speed and power density, all-SiC power modules are built and implemented for CSRs. The switching waveforms in the commutation are measured and studied based on double pulse test. Four different modulation schemes are compared for high efficiency CSR considering the switching characteristics of different device combinations. The most advantageous modulation scheme is then identified for each of the device combinations investigated. A compensation method is proposed to reduce the input current distortion caused by overlap time and slow transition in CSRs. The proposed method first minimizes the overlap time and then compensates the charge gain/loss according to the sampled voltage and current. It is verified that the proposed method can reduce the input current distortion especially when the line-to-line voltage is close to zero. The dc-link current will become discontinuous under light load in CSRs, when the traditional control algorithm may not work consistently well. To operate CSR in discontinuous current mode (DCM), the CSR is modeled in DCM and a new control algorithm with feedforward compensation is proposed and verified through experiments.
LINK ORIGINAL  WEB
http://trace.tennessee.edu/cgi/viewcontent.cgi?article=4357&context=utk_graddiss

ADVANCE THREE PHASE POWER FACTOR CORRECTION SCHEMES FOR UTILITY INTERFACE OF POWER ELECTRONIC SYSTEMS A Thesis by MESAAD WALEED ALBADER -Texas A&M University



ADVANCE THREE PHASE POWER FACTOR CORRECTION SCHEMES FOR UTILITY INTERFACE OF POWER ELECTRONIC SYSTEMS A Thesis by MESAAD WALEED ALBADER Submitted to the Office of Graduate and Professional Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE

Chair of Committee, Prasad Enjeti
Co-Chair of Committee, Hamid Toliyat
Committee Members, Shankar P. Bhattacharyya
Won-Jong Kim
Head of Department, Chanan Singh
August 2014
ABSTRACT
 Modern power electronic systems operate with different voltage and/or frequency rating such as Adjustable speed drive, Micro Grid, Uninterruptable Power Supplies (UPS) and High Voltage DC Transmission Systems. To match power electronic systems with the mains supply, DC link converters are used. The first stage of the DC link converter is the AC/DC conversion (rectifier). The rectifier type utility interface has substantial harmonics result in poor power quality due to low power factor and high harmonic distortion. Power Factor Correction (PFC) schemes are effective methods to mitigate harmonics and address this issue. In this thesis, analyses of three approaches for high power density rectifiers are developed. In the first study, modular three phase boost rectifiers operating in DCM are coupled in order to increase the power density. Major drawback of this rectifier is the high currents ripple in both the source and the DC link sides which require large EMI filter size -could be larger than the rectifier component size- and large DC filter capacitor size. This thesis proposes coupling modular three phase boost DCM rectifiers, the currents in both source and DC link sides are interleaved and consequently the currents ripple dramatically decreased results in small component size of the EMI filter and the DC filter capacitor leading to high power density rectification. Also, optimization of the number of the rectifier modules to achieve maximum power density is presented. Moreover, the switching function of each rectifier employs harmonic injection technique to reduce the low order harmonics. And, the DC output voltage is varied with the load power such that the operation is at the boundary between CCM and DCM to achieve maximum power density tracking.
 LINK ORIGINAL THESIS
http://oaktrust.library.tamu.edu/bitstream/handle/1969.1/153331/ALBADER-THESIS-2014.pdf?sequence=1

Eric Giler: A demo of wireless electricity


Eric Giler: A demo of wireless electricity
LINK https://www.ted.com/talks/eric_giler_demos_wireless_electricity

TESLA Wireless Power Transmitter and the Tunguska Explosion of 1908 -Беспроволочная технология передачи энергии Н.Тесла и Тунгусский взрыв




Nikola Tesla and Tunguska On June 30, 1908, over 100 years ago, a huge explosion destroyed over 1,000 miles of a very remote and sparsely inhabited region of central Siberia. The exact date of the event is very uncertain because nobody from the outside reached the region until 1927, and there is an 11 day difference between the Julian calendar then used by the Russians, and the Gregorian calendar which supplanted the Julian calendar. In 1582, Pope Gregory XIII massacred the calendar by taking out 11 days in the month of October. The Russians did not convert to the Gregorian calendar until after the 1917 Russian Revolution. About June 30,1908, a huge explosion completely devastated a 2,600 square kilometer area of Siberia. This explosion was 1,000 times more powerful than the Hiroshima atomic bomb, and larger than the devastation caused by subsequent nuclear bomb testing by the U.S. and Russia. Because of the remote location, the Russian Revolution, and Civil War, an expedition did not reach Tunguska until 1927. Initial reports said that it was a meteorite because a celestial phenomenon like the northern lights or aurora borealis could be seen as far south as London. This explosion was not a meteorite or visitors from outer space....It was the work of the super Serbian scientist named Nikola Tesla.
 SOURCE ORIGINAL
http://www.reformation.org/tesla-and-tunguska.html

Circuit Theory I


Lecture Notes

WeekLectureNotes
Week 1Circuit Theory I: goals and underlaying assumptions
Week 2Circuit Variables
Week 3Circuit Elements
Week 4Resistive Circuits
Week 5Circuit Analysis Techniques and Theorems
Week 6Operational Amplifier
Week 7Operational Amplifier Imperfections
Week 8Energy Storage Elements and transformers
Week 9First order RC and RL circuits
Examples of Sequential Switching Circuits
Week 10RLC circuits: part a   part b
Anant Agarwaland Jeffrey Lang, course materials for 6.002 Circuits and Electronics, Spring 2007. MIT OpenCourseWare(http://ocw.mit.edu/), Massachusetts Institute of Technology.
Downloaded on [2 Dec 2009]

LINK ORIGINAL EN LA WEB
https://www.blogger.com/blogger.g?blogID=1078288880652113587#editor/target=post;postID=2934418545071209264


sábado, 17 de setembro de 2016

CONFERENCIA SEGURIDAD ELÉCTRICA EN CENTROS QUIRÚRGICOS Y SALAS DE OPERACIONES -FACULTAD DE INGENIERIA ELÉCTRICA Y ELECTRÓNICA DE LA UNIVERSIDAD NACIONAL MAYOR DE SAN MARCOS



PES UNMSM 
Buenas noches con todos compañeros, nuestros amigos del Capitulo Estudiantil EMB-UNMSM de la Escuela de Electrónica, Invita a todos los interesados en la Especialidad Biomedica a participar de esta tarde de conferencias. LUGAR: Auditorio del Pabellón A (Puerta 3) DIA: Miércoles, 21 de septiembre.
 Mas información e inscripciones escribir al correo ieee.emb.unmsm@gmail.com

sexta-feira, 16 de setembro de 2016

Evaluation of Wireless Resonant Power Transfer Systems With Human Electromagnetic Exposure Limits Andreas Christ, Mark G. Douglas, Senior Member, IEEE, John M. Roman, Member, IEEE, Emily B. Cooper, Member, IEEE





Abstract—This study provides recommendations for scientifi- cally sound methods of evaluating compliance of wireless power transfer systems with respect to human electromagnetic exposure limits. Methods for both numerical analysis and measurements are discussed. An exposure assessment of a representative wireless power transfer system, under a limited set of operating conditions, is provided in order to estimate the maximum SAR levels. The system operates at low MHz frequencies and it achieves power transfer via near field coupling between two resonant coils located within a few meters of each other. Numerical modeling of the system next to each of four high-resolution anatomical models shows that the local and whole-body SAR limits are generally reached when the transmit coil currents are 0.5 ARMS – 1.2 ARMS at 8 MHz for the maximal-exposure orientation of the coil and 10-mm distance to the body. For the same coil configurations, the exposure can vary by more than 3 dB for different human models. A simplified experimental setup for the exposure evaluation of wireless power transfer systems is also described.

LINK
http://sensor.cs.washington.edu/pubs/power/magnetic_resonance_human_em_exposure.pdf

segunda-feira, 12 de setembro de 2016

Conversor CC-CC tipo T ZVS PWM: análise, projeto e implementação Autor:Bandeira Junior, Delvanei Gomes -Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Elétrica, Florianópolis, 2014 BRASIL.



Conversor CC-CC tipo T ZVS PWM: análise, projeto e implementação Autor: Bandeira Junior, Delvanei Gomes Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Elétrica, Florianópolis, 2014.

 LINK ORIGINAL DA DISSERTAÇÃO DE MESTRADO https://repositorio.ufsc.br/handle/123456789/128980

 LINK DIRECTO ARQUIVO PDF 
https://repositorio.ufsc.br/bitstream/handle/123456789/128980/328199.pdf?sequence=1&isAllowed=y

 Abstract : This work presents the analysis of the T-Type Zero Voltage Switching Pulse Width Modulated isolated DC-DC converter (TT-ZVS-PWM Converter). The topology is composed of four switches. Two of them are subjected to the input voltage level and the other two to half the input voltage. All primary side switches commutate under zero-voltage. The proposed converter has the following in common with the Full Bridge Zero-Voltage Switching (FB-ZVS-PWM) and the Three-Level Zero-Voltage Switching (TL-ZVS-PWM) converters: (a) symmetrical operation of the isolation transformer, (b) modulation by pulse-width with constant frequency, (c) zero voltage switching, and (d) three-level voltage applied to the primary winding of the transformer. Theoreticalanalysis, small signal model, design example and experimental results for a 3 kW, 400 VDC input, 60 VDC output, and 50 kHz switching frequency laboratory prototype, are included. Measured efficiency was 93% at full load and a peak efficiency of 95.2% occured at 1.2 kW.

 RESUMO Este trabalho apresenta o estudo de um conversor CC-CC isolado com comutação suave, saída em corrente, para aplicações envolvendo altas potências, com nome T-Type Zero Voltage Switching Pulse Width Modulated dc-dc converter(TT-ZVS-PWM). O conversor a ser estudado possui quatro interruptores. Dois deles são submetidos à tensão de entrada, já os outros dois são submetidos à metade da tensão de entrada. Todos os interruptores comutam sob tensão nula. O conversor proposto possui as seguintes semelhanças com os conversores Full Bridge Zero Voltage Switching(FB-ZVS-PWM) e Three Level Zero Voltage Switching(TL-ZVS-PWM): (a) Operação simétrica (b) Modulação por largura de pulso com frequência constante (c) comutação sob tensão nula e (d) tensão de saída do conversor com três níveis, a ser aplicada nos terminais do primário do transformador. O trabalho é dividido em análise teórica, análise do modelo de pequenos sinais do conversor e roteiro para projeto do conversor. Um protótipo com 3 kW, 400 V de entrada, 60V de saída e frequência de comutação de 50 kHz comprova a análise desenvolvida. A eficiência obtida no protótipo foi de 93% para carga nominal e de 95,2% para 1,2 kW

sábado, 10 de setembro de 2016

Power Transfer Through Strongly Coupled Resonances by André Kurs Master of Science in Physics at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY


Power Transfer Through Strongly Coupled Resonances by André Kurs

Submitted to the Department of Physics in partial fulfillment of the requirements for the degree of Master of Science in Physics at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY September 2007.

 Chapter 1
 Introduction
At the turn of the 20th century, Nikola Tesla [1, 2, 3] devoted much effort to developing a system for transferring large amounts of power over continental distances. His main goal was to bypass the electrical-wire grid, but for a number of technical and financial difficulties, this project was never completed. Moreover, typical embodiments of Tesla's power transfer scheme (e.g., Tesla coils) involve extremely large electric fields and are potential safety hazards. The past decade has witnessed a dramatic surge in the use of autonomous electronic devices (laptops, cell-phones, robots, PDAs, etc) whose batteries need to be constantly recharged. As a consequence, interest in wirelessly recharging or powering such devices has reemerged [4, 5, 6]. Our attempts to help to fulfill this need led us to look for physical phenomena that would enable a source and a device to exchange energy efficiently over mid-range distances, while dissipating relatively little energy in extraneous objects. By mid-range, we mean that the separation between the two objects effecting the transfer should be of the order of a few times the characteristic sizes of the objects. Thus, for example, one source could be used to power or recharge all portable devices within an average-sized room. A natural candidate for wirelessly transferring powering over mid-range or longer distances would be to use electromagnetic radiation. But radiative transfer [7], while perfectly suitable for transferring information, poses a number of difficulties for power transfer applications: the efficiency of power transfer is very low if the radiation is omnidirectional (since the power captured is proportional to the cross-section of the receiving antenna, and most of the power is radiated in other directions), and requires an uninterrupted line of sight and sophisticated tracking mechanisms if radiation is unidirectional (which might also damage anything that interrupts the line of sight). An alternative approach, which we pursue here, is to exploit some near-field interaction between the source and the device, and somehow tune this system so that efficient power transfer is possible. A recent theoretical paper [8] presented a detailed analysis of the feasibility of using resonant objects coupled through their near-fields to achieve mid-range energy transfer. The basic idea is that in systems of coupled resonances (e.g. acoustic, electro-magnetic, magnetic, nuclear), there may be a general strongly coupled regime of operation [9]. It is a general physical property that if one can operate in this regime in a given system, the energy transfer is expected to be very efficient. Mid-range power transfer implemented this way can be nearly omnidirectional and efficient, irrespective of the geometry of the surrounding space, and with low losses into most off-resonant environmental objects [8]. The above considerations apply irrespective of the physical nature of the resonances. In the current work, we focus on one particular physical embodiment: magnetic resonances [10], meaning that the interaction between the objects occurs predominantly through the magnetic fields they generate. Magnetic resonances are particularly suitable for everyday use because biological tissue and most common materials do not interact strongly with magnetic fields, which helps make the system safer and more efficient. We were able to identify the strongly coupled regime in the system of two coupled magnetic resonances by exploring non-radiative (nearfield) magnetic resonant induction at MHz frequencies. At first glance, such power transfer is reminiscent of the usual magnetic induction [11]; however, note that the usual non-resonant induction is very inefficient unless the two coils share a core with high magnetic permeability or are very close to each other. Moreover, operating on resonance is necessary but not sufficient to achieve good efficiency at mid-range distances. Indeed, Tesla's pioneering work made extensive use of resonant induction, and many technologies available today (e.g., radio receivers, RFID tags, and cochlear implants [12]) also rely on resonance, yet their efficiencies are not very good at mid range distances. Operation in the strong-coupling regime, for which resonance is a precondition, is what makes the power transfer efficient.

LINK THESIS
http://www.mediafire.com/download/ctld702cydgxh4c/317879200-MIT.pdf

About Wireless Power Transfer


I talk about magnetically coupled wireless electricity technology. Lots about inductors, Q factor, AC losses and what this all means for practical implementations of wireless power transmission.
 Main article is here: http://www.vk2zay.net/article/253
 Circuit of demo TX/RX here: http://www.vk2zay.net/article.php/262

Circuitos Elétricos - Aula 13 - Redes de 1ª Ordem - Parte 1 - Professor ministrante: Leopoldo R. Yoshioka


Engenharia de Computação Univesp - Circuitos Elétricos Curso de Engenharia de Computação Disciplina EEC-001 - Circuitos Elétricos Univesp - Universidade Virtual do Estado de São Paulo Professor responsável: João Francisco Justo Filho Professor ministrante: Leopoldo R. Yoshioka

INDUCTIVE POWER TRANSFER TECHNOLOGY FOR MOBILE BATTERY CHARGER by SATISH ROUSHAN. Department of Electrical Engineering National Institute of Technology Rourkela- INDIA-2014





INDUCTIVE POWER TRANSFER TECHNOLOGY FOR MOBILE BATTERY CHARGER

 A Thesis presented in partial fulfillment of the exigency for the degree of Bachelor of Technology in “Electrical Engineering” 
By SATISH ROUSHAN
 Under guidance of Prof. SUSOVAN SAMANTA


ABSTRACT

 Inductive power transfer (IPT) is an application of electromagnetic induction principle. Since electromagnetic induction phenomena is directly proportional to the operating frequency, so as we increase the operating frequency, amount of energy transfer from one coil to another coil will also increase. As our power supply frequency is 50Hz so at this frequency, amount of energy transfer from one coil to another coil will be very less. In this thesis it is shown that, to transfer maximum amount of energy from one coil to another coil, it is necessary to use IPT at high frequency. At high frequency skin effect is more pronounced but there is a resonant frequency where overall efficiency is more in spite skin effect. To increase the power factor of IPT circuit compensated capacitor has used. There are four types of compensated topology but to use the IPT circuit in mobile battery charger primary-series-secondary-parallel (P-S-S-P) is more useful.

LINK ORIGINAL EN LA WEB
http://ethesis.nitrkl.ac.in/6417/1/E-85.pdf

sexta-feira, 9 de setembro de 2016

Lançamento da nova família de nobreaks senoidais Smart-UPS BR


A qualidade da energia elétrica brasileira em geral tem melhorado nos últimos anos no que tange aos indicadores de continuidade descritos no módulo 8 do PRODIST (Procedimentos de Distribuição de Energia Elétrica no Sistema Elétrico Nacional), porém mesmo com a modernização das redes de distribuição, as concessionárias necessitam investir na melhoria da gestão. Segundo a ANEEL, a média dos indicadores DEC (número de horas, em média, que o consumidor fica sem energia elétrica no ano) e FEC (quantas vezes em média houve interrupção no fornecimento de energia) de 2015 ficaram, respectivamente, em 18 horas e 35 minutos e 9,86 vezes. O valor do FEC diminuiu em relação ao ano passado e apresenta um padrão de queda desde 2010. Já o DEC, que também estava em queda, aumentou se comparado com o ano de 2014. Ou seja, os consumidores em média ficaram mais tempo sem energia elétrica.

Vislumbrando o aumento crescente do mercado de médios e pequenos servidores, além das aplicações de TI em indústrias, equipamentos médicos, circuitos CFTV, pontos de vendas e caixas eletrônicos, a APC by Schneider Electric está lançando a nova família de nobreaks Smart-UPS BR. Serão lançados cinco novos produtos com potência de 2200W e 3000W e tensão de alimentação bivolt e monovolt . Esta nova linha de nobreaks foi totalmente desenvolvida no Brasil pelo centro de P&D da Schneider Electric e atende às necessidades e particularidades do mercado brasileiro, com a confiabilidade lendária e tecnologia da APC by Schneider Electric. LINK ARTIGO COMPLETO ORIGINAL NA WEB
http://blog-br.schneider-electric.com/inovacao/2016/09/09/lancamento-nobreaks-senoidais-smart-ups/

Electromagnetism Sejong University PROF. YONGHO SEO PhD. Associate Professor - 전자기학 세종대학교 서용호



Electromagnetism Sejong University PROF. YONGHO SEO - 전자기학 세종대학교 서용호

Yongho Seo, PhD. Associate Professor
LINK FULL COURSE ELECTROMAGNETISM

http://home.sejong.ac.kr/~yseo/

Personal Date
Name, Family name: Seo
Given name: Yongho
Sex: Male
Nationality: Korean (ROK)
Office (mailing) address: 98 Gunja-dong, Gwangjin-gu, Sejong Univ. Choongmu-kwan room 816,
Seoul 143-747, South Korea
Tel: 82-2-3408-3689
E-mail: yseo@sejong.ac.kr
Education
1989-1993 : B.S. Department of Physics, Sogang University, Seoul, Korea, obtained in Feb. 1993
1993-1995 : M.S. Department of Physics, Seoul National University, obtained in Feb. 1995
1997-2000 : Ph.D Department of Physics, Seoul National University, obtained in Feb. 2000
Ph. D thesis "Study of Adsorption and Wetting using Quartz Crystal Microbalance"
Employment history
1994-1995: Teaching Assistant, Department of Physics, Seoul National University.
1995-1997: Research Assistant, Department of Physics, Seoul National University.
1997-1999: Teaching Assistant, Department of Physics, Seoul National University.
2000- 10/2002: Researcher, Center for Near-field Atom-Photon Technology, Seoul National University.
2002.10-2004.05: Research Associate in Physics department in University of Virginia.
2004.06-2005.05: Postdoc. Dept. Physics and Astronomy, Northwestern University.
2005.07-2006.02: Research staff, Samsung Advanced Institute of Technology.
2006.03-2010.02: Assistant Professor, Dept. Nano-engineering, Sejong University.
2010.03-present: Associate Professor, Dept. Nano-engineering, Sejong University.