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, 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

sábado, 3 de dezembro de 2016

Communication Circuits: Analysis and Design by Kenneth K. Clarke




Communication Circuits: Analysis and Design by Kenneth K. Clarke ESTUDIE CIRCUITOS ELECTRONICOS III CON ESTE LIBRO EN LA FACULTAD DE INGENIERIA ELECTRÓNICA DE LA UNIVERSIDAD NACIONAL MAYOR DE SAN MARCOS SIENDO MI PROFESOR EL ILUSTRE PROF. Carlos Sanchez Tarnawiecki hoy Profesor del Postgrado at Universidad Nacional Mayor de San Marcos

LINK ORIGINAL EN LA WEB
http://www.samanezehn.com/ketab2.pdf
LINK ALTERNATIVO
http://www.mediafire.com/file/a937ig695iiah4a/communication_circuits.pdf