No Blog Eletrônica de Potência você encontrará informações sobre teses,artigos,seminarios,congressos,tecnologias,cursos,sobre eletrônica potência. “TEMOS O DESTINO QUE MERECEMOS. O NOSSO DESTINO ESTA DE ACORDO COM OS NOSSOS MERITOS” ALBERT EINSTEIN. Imagination is more important than knowledge, for knowledge is limited while imagination embraces the entire world. EL FUTURO SE CONSTRUYE HOY,EL SUCESSO NO ES FRUTO DE LA CASUALIDAD,SE HUMILDE ,APRENDE SIEMPRE CADA DIA.
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"
quinta-feira, 3 de novembro de 2016
BREAKDOWN VOLTAGE PERFORMANCES OF ALUMINUM AND COPPER CONDUCTOR WIRE UNDER COMPRESSION STRESSES -Richard Donald Suchanek - Western Kentucky University Master of Science
BREAKDOWN VOLTAGE PERFORMANCES OF ALUMINUM AND COPPER CONDUCTOR WIRE UNDER COMPRESSION STRESSES
A Thesis Presented to The Faculty of the Department of Architectural and Manufacturing Sciences Western Kentucky University Bowling Green, Kentucky
In Partial Fulfillment Of the Requirements for the Degree Master of Science By Rich Suchanek
May 2016
ABSTRACT
In the global, competitive market of energy transformation, increased operational expenses and depletion of raw materials have resulted in companies pursuing alternate materials to reduce consumer costs. In electrical applications, energy is transformed using materials with high electrical conductive properties. The conductive material used to transmit a signal is called conductor wire and is comprised of any material that has the ability to move charged particles from one point to another without propagation or delay. The conductor wire in many applications is encapsulated in epoxy resin called enamel. The enamel is the insulation system that provides necessary dielectric clearances to prevent voltage leakage. The most common form of energy transformation is the electric motor. Both copper and aluminum conductor wire are commonly used in electric motors, but copper is preferred due to thermal and electrical properties. However, there is a significant economic incentive to convert to aluminum conductor wire. Limited white papers are available comparing the performances of the two materials; the research is limited to physical and electrical performances of the raw material and does not take into considering the insulation. The conductor wire, which includes the insulation, is susceptible to damage during the manufacturing process and is an inherent risk if not fully understood. During the blocking process, the conductor wire is pushed and compressed into lamination slots. This process changes the conductor wire outer diameter to accommodate void spaces within the lamination slots. The percentage of slot vii area occupied by the conductor wire is known as slot fill. The higher the slot fill, the more wire occupying the available space. The higher the slot fill, the more force required to fill the slots. High slot fill motor designs provide a performance advantage with little associated cost. The more wire pressed into the slot, the higher the potential efficiency gains. However, high slot fill motors are more susceptible to damage. The study is designed to evaluate and measure the durability of aluminum and copper conductor wire under simulated compression stresses. Utilizing this information, electric motor manufacturers can push current design limits without affecting conductor wire quality and reliability.
FULL THESIS LINK ORIGINAL:
http://digitalcommons.wku.edu/cgi/viewcontent.cgi?article=2611&context=theses
quarta-feira, 2 de novembro de 2016
Live: Chinese astronauts enter Tiangong-2 space lab from Shenzhou-11 spacecraft
China's manned spacecraft, Shenzhou-11, docks with space lab Tiangong-2. The spacecraft was launched into orbit on Monday, carrying two astronauts who plan to stay in the space lab for 30 days. The crewed mission marks a key step toward China's plan to eventually operate a permanent space station.
sexta-feira, 28 de outubro de 2016
ARC FLASH HAZARDS ANALYSIS by ZHENYUAN ZHANG Graduate School of The University of Texas at Arlington 2015
ARC FLASH HAZARDS ANALYSIS by ZHENYUAN ZHANG
Presented to the Faculty of the Graduate School of The University of Texas at Arlington in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY THE UNIVERSITY OF TEXAS AT ARLINGTON
Abstract
ARC FLASH HAZARDS ANALYSIS Zhenyuan Zhang, PhD The University of Texas at Arlington, 2015
Supervising Professor: Wei-Jen Lee
Annually more than 2000 workers are admitted to hospital burn centers for extensive injuries caused by arc flash accidents. Arc flash incidents occur when unintended electric current flows through air, superheating the air and causes an explosion. Recognizing the significant threat posed by arc flash hazards, IEEE and NFPA have joined forces on an initiative to support research and additional testing to increase the understanding of the arc flash phenomena. Accurately represent all the real applications for arc flash events are very difficult, not only because of their random complex nature, but also because a large number of uncertain variables involved. Several areas of the arc flash phenomena need further research and testing validation. In order to have a precise arc flash hazards assessment, approximately 2000 arc flash experiments had been conducted, which are crossed extensive range of system voltage, bolted fault current, electrodes gap width, arc initiative configuration and enclosure dimensions. This dissertation has reviewed the testing methodology, test equipment design and modeling process for arc flash hazards analysis. The research and testing focused on, but will not be limited to (a) the development of physics and engineering-based modeling for arc flash thermal hazards, and (b) design and testing for non-thermal hazards, such as light, pressure and sound. Based on the works of the dissertation, sets of assessment equations and approaches have been proposed for arc flash thermal and non-thermal hazard analysis. The results of this dissertation will provide information to help more accurately predict the hazards associated with high energy arcing faults, thereby improving electrical safety standards and providing practical safeguards for employees in the work place.
LINK ORIGINAL
https://uta-ir.tdl.org/uta-ir/bitstream/handle/10106/25513/ZHANG-DISSERTATION-2015.pdf?sequence=1
LINK ALTERNATIVO
http://www.mediafire.com/file/2wbqqd7064st7ei/ZHANG-DISSERTATION-2015.pdf
quinta-feira, 27 de outubro de 2016
High-Performance Control of Three-Phase Four- Wire DVR Systems using Feedback Linearization Seon-Yeong Jeong*, Thanh Hai Nguyen**, Quoc Anh Le**, and Dong-Choon Lee†
High-Performance Control of Three-Phase Four- Wire DVR Systems using Feedback Linearization Seon-Yeong Jeong*, Thanh Hai Nguyen**, Quoc Anh Le**, and Dong-Choon Lee† *Department of Research and Development, T.E.C.C. Co. Ltd., Daegu, Korea **,†Department of Electrical Engineering, Yeungnam University, Gyeongsan, Korea
Abstract
Power quality is a critical issue in distribution systems, where a dynamic voltage restorer (DVR) is commonly used to mitigate the voltage disturbances for loads. This paper deals with a nonlinear control for the three-phase four-wire (3P-4W) DVR under a grid voltage unbalance and nonlinear loads in the distribution system, where a novel control scheme based on the feedback linearization technique is proposed. Through feedback linearization, a nonlinear model of a DVR with a PWM voltage-source inverter (VSI) and LC filters is linearized. Then, the controller design of the linearized model is performed by applying the linear control theory, where the load voltages are kept constant by controlling the d-q-0 axis components of the DVR output voltages. To keep the load voltage unchanged, an in-phase compensation strategy is employed, where the load voltages are recovered to be the same as the previous voltage without a change in the magnitude. With this strategy, the performance of the DVR becomes faster and more stable even under unbalanced source voltages and nonlinear loads. The validity of the proposed control strategy has been verified by simulation and experimental results.
Key words: Dynamic voltage restorers, feedback linearization, SOGI-PLL, three-phase four-wire VSI, voltage unbalance
LINK: http://ocean.kisti.re.kr/downfile/volume/kipe/E1PWAX/2016/v16n1/E1PWAX_2016_v16n1_351.pdf
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