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”

sábado, 24 de dezembro de 2016

DR. Slobodan Cuk - Group POWER ELECTRONICS INSTITUTE



Prof Gustavo Castelo Branco, Prof Slobodan Cuk e Prof Armando Cavero Miranda -Brazilian Power Electronics Conference -Cobep/Spec - 2015 -FORTALEZA-CEARÁ-BRASIL

  DR. Slobodan Cuk 

I am Yugoslav/Serbian who came to United States as an immigrant on flight from Belgrade, Yugoslavia on February 29, 1972 sponsored by NASA. NASA first supported at Santa Clara my MS thesis: “Stability Investigations of the Spinning Skylab” and my 2-year doctorate at Caltech from Sept. 1974 to Dec. 1976. This latter work is now part of the new Vol. 4: “State Space Averaging and Cuk converters”. Vol.1 and Vol. 4 are now combined into a 624-page 40-th anniversary paperback edition while Vol.2 and vol. 3 are combined into 631-page paperback. Kindle editions are also available now individually and as four volume bundle. 1. teslaco.com 2. YouTube.com/c/slobodancukTESLAco 3. Amazon.com/author/slobodancuk 4. linkedin.com/groups/7045487. 5. cuk@teslaco.com; 6. Linkedin.com/in/slobodancuk. Many generations of engineers used these books to get into emerging Power Electronics field and more than 4,000 used them as textbooks in courses I presented. One of my 35 PhD students, now professor, endorsed these books on Amazon with: “This Power Electronics Series is a record of a Big Bang in the History of Power Electronics!” The combined vol.1 and vol.4 paperback and my past research work led me to conclude that a critical re-evaluation is badly needed of the conventional buck, boost, flyback, forward, bridge-type, LLC and other converters which dominated industry for the last 60 years! This is now addressed in the upcoming volume 5! The time has now also come for their replacement by new Power Electronics System Technology based on three new Resonant/PWM type switching methods, related host of novel converter topologies and new magnetics structures I introduced in last 6 years via patents, articles and presentations! They and my contemporary column with articles on teslaco.com home page are slated for upcoming Volume 6 of this series! A well respected Power Electronics expert recently commented to his LinkedIn group: “You should all read everything that Dr. Ćuk has ever written!”.

LINK
https://www.amazon.com/Slobodan-Cuk/e/B00IYCSWQ0

terça-feira, 20 de dezembro de 2016

Efficiency Improvement of Flyback Converter Using Stepped-Airgap Inductor 계단형 공극 인덕터를 이용한 Flyback Converter의 효율 개선 Yong-Hwan Shin - Department of Electrical Engineering - Gyeongsang National University-South Korea








Efficiency Improvement of Flyback Converter
Using Stepped-Airgap Inductor

계단형 공극 인덕터를 이용한 Flyback Converter의 효율 개선
Yong-Hwan Shin
Department of Electrical Engineering
Graduate School
Gyeongsang National University

Abstract
This thesis deals with the efficiency improvement of flyback converter using stepped-airgap transformer, in order to improve the efficiency and/or power density of power electronic systems. The stepped-airgap inductor has been proposed for the flyback converter in order to improve the efficiency over the entire load range, especially light load. The design procedure is also presented. The center leg has typical air gap while the outer gap has a step-shape core. The inductance of the flyback transformer is increased at light load, so that CCM operation can be extended to lighter load. In addition, both the air gaps in the center and outer legs operate at heavy load, so that the AC winding loss can be reduced. The usefulness of the proposed flyback transformer is experimentally verified and compared with the conventional flyback transformer with one inductance value. The experimental results show that the proposed stepped-airgap transformer has higher efficiency at not only light load but also heavy load. Especially, light load efficiency can be much improved. The first part of the thesis introduced method improving flyback converter at light load. Improving efficiency is introduced by many other methods at the entire load. Efficiency is also compared with switching frequency and variable inductance at the entire load. To improve efficiency at light load, stepped-airgap core was suggested. The second part of the thesis introduces how to model stepped-airgap for reluctance circuit. Stepped-airgap is calculated by stepped air gap length and stepped core area. Inductance is analyzed by relative permeability. According to current, stepped-airgap inductor have linear, saturated and hard saturated region. To analyze stepped-airgap is also calculated by flux intensity. Finally, stepped-airgap inductor is summarized by the inductance and relative permeability according to inductor current. The third part of the thesis deals with design of stepped-airgap inductor and flyback transformer. Stepped-airgap is simulated by Maxwell 3D and PSIM simulation tools according to inductor current. To improve efficiency of flyback converter can extend the CCM range with changeable inductance value. Before experiment of flyback converter, simulation is preceded using Maxwell 3D program to confirm permeance, relative permeability value and flux density at stepped core. The operation of flyback converter with varying load current is also simulated by PSIM program. The fourth part of the thesis deals with measurement of inductance about stepped-airgap inductor. Inductance is measured by circuit that can measure the inductance according to current. When input current is changed, inductance is measured by LCR Meter using DC power supply. Inductance is also measured to change part of stepped core area. Until now, there is no relative permeability data of PC95 according to current. Relative permeability of PC95 is gathered by measurement in lab. Stepped-airgap inductor is analyzed and modeling about length of air gap and core area by PC95 relative permeability data. Relative permeability of PC95 is also described that inductance curve about change of current and compared with normal air gap inductor. The fifth part of the thesis deals with experiment of flyback converter with stepped-airgap transformer. Efficiency of converter is measured when the load is changed from high to low or low to high. The waveform is measured when the converter is entered the CCM, CRM and DCM. To verify theory the experimental results is confirmed by measured ring of vds voltage for extended CCM range over the entire load. The sixth part of the thesis deals with conclusion of flyback converter with stepped-airgap transformer. Stepped-airgap inductor advantage to improve the efficiency of flyback converter over the entire load range. The thesis researches the pros and cons of the stepped-airgap transformer. Stepped-airgap transformer using variable inductance will improve efficiency of other many converters, especially efficiency of magnetics components.

segunda-feira, 12 de dezembro de 2016

Contribuições ao controle eletrônico inteligente de reguladores de tensão para sistemas de distribuição de energia em 13,8 kV - RODRIGO RIMOLDI DE LIMA- Dissertação (Mestrado)-Universidade Federal de Uberlândia, Uberlândia- BRASIL







Título: Contribuições ao controle eletrônico inteligente de reguladores de tensão para sistemas de distribuição de energia em 13,8 kV Outros títulos: Contributions to the intelligent electronic control of voltage regulators for systems of energy distribution in 13,8 kV .

Data de publicação: 20-Jul-2007

 Citação: LIMA, Rodrigo Rimoldi de. Contribuições ao controle eletrônico inteligente de reguladores de tensão para sistemas de distribuição de energia em 13,8 kV. 2007. 143 f. Dissertação (Mestrado)-Universidade Federal de Uberlândia, Uberlândia, 2007. 

Resumo: O desenvolvimento proposto neste trabalho excede à operação convencional até então praticada por apresentar em seu dorso um circuito eletrônico microcontrolado que atua sobre a carga do sistema por intermédio de 09 taps de regulação (02 de abaixamento, 06 de elevação e o central) de modo totalmente independente e com grande velocidade de resposta, posto que a regulagem foi procedida com tempo limite de 04 ciclos da rede elétrica. Cada estágio de regulação proporciona uma variação de 5% sobre o valor nominal da tensão entregue à carga, estabelecendo um amplo controle para valores entre 70% e 110% do sinal fornecido à mesma. A comunicação desta com o módulo de controle mencionado é feita através de tiristores (SCR’s) com refrigeração a ar.
LINK ORIGINAL
http://penelope.dr.ufu.br/handle/123456789/333
LINK THESIS
Arquivos neste item:
ArquivoDescriçãoTamanhoFormato
ContribuiçõesControleEletrônico_parte 1.pdf2.38 MBAdobe PDFver/abrir
ContribuiçõesControleEletrônico_parte 2.pdf3.7 MBAdobe PDFver/abrir
ContribuiçõesControleEletrônico_parte 3.pdf3.85 MBAdobe PDFver/abrir

domingo, 11 de dezembro de 2016

Automatic Test System for Type Tests of the Uninterruptible Power Supply -Esa Nummijoki - Aalto University School of Electrical Engineering-HELSINKI-FINLAND






Author: Esa Nummijoki 
Title: Automatic Test System for Type Tests of the Uninterruptible Power Supply 
Date: 27.3.2012
 Language: English 

School of Electrical Engineering Thesis submitted for examination for the degree of Master of Science in Technology.
 AALTO SCHOOL UNIVERSITY  OF ELECTRICAL ENGINEERING

 Abstract of the master's thesis 

 Testing is an essential part of product development. In UPS product development, di erent tests are made every day. Testing requires large variety of measurement instruments and other equipment such as large load systems and di erent kind of test con gurations. Signi cant number of performed tests are based on the UPS type tests de ned in the IEC-62040 standard. Testing consumes a lot of time and that way also resources. To solve this problem, an automatic test system for type tests is considered. The aim of this thesis was to clarify the need for the automatic test system, and clarify requirements needed to realize it. The work was done by reviewing the type tests and di erent parts of an automatic test system. In addition, an experimentation was made, resulting a prototype. The prototype is able to automatically perform an indicative e ciency test for the UPS. Furthermore, a possibility to automate the most complex type test, a dynamic output performance test, was examined. This examination resulted a description of the test process and LabVIEW programs, supporting the execution of the test. However, the conclusion was that it is not sensible to automate the test, due to the fact that it is not often performed and automating the test requires a lot of time and resources. The review and the experimentation proved that realization of an automatic test system, able to perform all the type tests, requires large amount of time and resources. Due to this, the automatic test system for type tests is not the best solution to reduce the time and resources consumed by testing.
 Keywords: Automatic Test System, Uninterruptible Power Supply, Product Development, LabVIEW, TestStand, Prototype

LINK  
http://www.mediafire.com/file/4wzvcknlxnpip4x/TESIS_TESTE_UPS_AUTOMATICO.pdf

Electrónica de potencia: componentes, topologías y equipos Por Salvador Martínez García,Juan Andrés Gualda Gil


EXCELENTE LIBRO DE ELECTRÓNICA DE POTENCIA DE LOS INGENIEROS
Salvador Martínez García,Juan Andrés Gualda Gil

LINK BOOK DEMO GOOGLE: 
https://books.google.com.br/books?id=izwxn8edxhAC&lpg=PR3&hl=pt-BR&pg=PR3#v=onepage&q&f=false BOOK DEMO GOOGLE

sábado, 10 de dezembro de 2016

Transformer Shielding Technique for Common Mode Noise Reduction in Switch Mode Power Supplies Yuchen Yang -Virginia Polytechnic Institute and State University









Transformer Shielding Technique for Common Mode Noise Reduction in Switch Mode Power Supplies Yuchen Yang
 Thesis submitted to the Faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of Master of Science in Electrical Engineering.

(Abstract)
 Switch mode power supplies are widely used in different applications. High efficiency and high power density are two driving forces for power supply systems. However, high dv/dt and di/dt in switch mode power supplies will cause severe EMI noise issue. In a typical front-end converter, the EMI filter usually occupies 1/3 to 1/4 volume of total converter. Hence, reducing the EMI noise of power converter can help reduce the volume of EMI filter and improving the total power density of the converter. For off-line switch mode power supplies, DM noise is dominated by PFC converter. CM noise is a more complicated issue. It is contributed by both PFC converter and DC/DC converter. While many researches have focused on reducing CM noise for PFC converter, the CM noise of DC/DC converter still remains a challenge. The main objective of this thesis is provide a solution to have best CM noise reduction for DC/DC converters. The shielding concept and balance concept are combined to propose a novel balance double shielding technique. This method can have an effective CM noise reduction in the circuit level. In addition it is easy to design and implement in the real production. The balance condition is easily controlled and guarantees effective CM noise reduction in mass production. Then, a novel one-layer shielding method for PCB winding. transformer is provided. This shielding technique can block CM noise from primary side and also cancel the CM noise from secondary side. In addition, shielding does not increase the loss of converter too much. Furthermore, this shielding technique can be applied to matrix transformer structure. For matrix transformer LLC converter, the inter-winding capacitor is very large and will cause severe CM noise problem. By adding shielding layer, CM noise has been greatly reduced. In addition, by modifying the secondary winding, the loss on shielding layer is minimized and experiments show that the total efficiency of converter has almost no impact. Furthermore, although this thesis uses flyback and LLC resonant converter as example to demonstrate the concept, the novel shielding technique can also be applied to other topologies that have similar transformer structure.

 LINK ORIGINAL WEB
https://vtechworks.lib.vt.edu/bitstream/handle/10919/49263/Yang_Y_T_2014.pdf?sequence=1

sexta-feira, 9 de dezembro de 2016

High Frequency-Link Cycloconverters for Medium Voltage Grid Connection -Shattock, Nicholas -PhD thesis, University of Nottingham.





High Frequency-Link Cycloconverters for Medium Voltage Grid Connection Nicholas Shattock BEng. (Hons) Thesis submitted to the University of Nottingham for the degree of Doctor of Philosophy 

Abstract
 As the deployment of renewable generation increases in the worldwide electrical grids, the development of distributed energy storage becomes more and more of an essential requirement. Energy storage devices connected at Medium Voltage allows for much higher powered deployments and this Ph.D. will focus on the power converter used to interface the energy storage device to the electrical grid. Multi-level converters can be used to provide this interface without huge ltering requirements or the need of a Low Frequency step up transformer. However traditional Multi-level converter topologies require a large number of electrolytic capacitors, reducing the reliability and increasing the cost. Multi-level converters constructed from a Cycloconverter Topology do not require any additional electrolytic capacitors, however the High Frequency transformer, used to provide isolation has to be considerably larger. This Ph.D. will investigate a novel hybrid converter topology to provide an interface between an energy storage device, such as a super-capacitor or battery, to the Medium Voltage grid, designed for high reliability and power density. This topology is called The Hybrid Cycloconverter Topology and is based on a Cycloconverter Topology connected to an auxiliary 3-Phase VSI. A comprehensive simulation study is carried out to investigate the semiconductor losses of this novel converter topology and compared against two alternative topologies. An experimental converter is constructed to validate the theory of operation and to justify its e ectiveness.

 LINK ORIGINAL
http://eprints.nottingham.ac.uk/14205/1/index2.pdf
LINK ALTERNATIVO
http://www.mediafire.com/file/yeyc074pn02azbq/High_Frequency-Link_Cycloconverters.pdf