quarta-feira, 27 de agosto de 2014
domingo, 24 de agosto de 2014
A Dissertation for the Degree of Doctor of Philosophy
Department of Information and Communications Engineering
Chungnam National University
ABSTRACT The economical and environmental impacts of fossil fuels have forced society to investigate sustainable solutions. The interest has focused on the renewable energy sources since the green and clean benefits. Consequently, investments in research and development in the field of power electronics have increased proportionally, especially in high voltage and high power grid-connected systems. The distributed power generation (DG) systems are becoming more common as the need for electric power increases because of taking advantage of using different energy sources such as wind and solar. A few examples are hybrid cars, solar houses or hospitals in remote areas where providing clean, efficient and reliable electric power is critical to the loads. In such systems, the power is distributed from the source side to the load side via power electronic converters in the system. At low and medium power applications, the task is often left to single-phase inverters where they are the only interface between sources connected to dc bus and loads connected to an ac bus. This dissertation investigates the power quality improvements to properly regulate the power flow between renewable source and the utility network. The control method for single-phase inverters used in low and medium power DG systems is based on (and also takes the advantage of) the well-known d-q transformation (which is mostly employed for three-phase converters’ analysis and control design).
sábado, 23 de agosto de 2014
THE NEXT GENERATION GRID-CONNECTED PV INVERTERS FOR HIGH
A Dissertation submitted to the
Department of Electrical and Computer Engineering
in partial fulfillment of the requirements for the degree of
Doctor of Philosophy Degree
THE FLORIDA STATE UNIVERSITY
ABSTRACT The increasing consumer demand and government incentives are driving the rapid growth of renewable energy generation. In particularly, the number of distributed photovoltaic (PV) system installations is increasing quickly. However, the high cost of the PV systems and the potential impacts on the safe operation of utility grid could become barriers to their future expansion. The transformerless cascaded multilevel inverter (CMI) is considered to be a promising topology alternative for low-cost and high-efficiency PV systems. This research work presents a single-phase transformerless PV system based on cascaded quasi-Z-source inverters (qZSI). In this system, each qZSI module is connected to a single PV panel and serves as a PV moduleintegrated converter (MIC).
quinta-feira, 21 de agosto de 2014
A Smart Lighting Management System with Satisfaction of User's Lighting Requirements Shin, Dae-Sik ; Kim, Hoon ;
Shin, Dae-Sik ; Kim, Hoon ;
In this paper, we proposed a smart lighting management system controls the lighting efficiently to reduce energy consumption while satisfying user's lighting requirements. The proposed system considers the available daylight intensity and indoor light source to satisfy the lighting requirements of each user according to the work environment. In addition, for user convenience, we have developed different user interfaces for lighting control including local interface, and remote interface through internet or Bluetooth for personal computer as well as smart phones. The proposed system satisfies the lighting requirements of each user according to the corresponding work environment. The proposed smart lighting management system utilizes the lighting energy efficiently, and can be considered a significant contribution towards future green buildings.
Development of High Efficiency and High Power LED Package for Applying Silicone-Reflector Jeong, Hee-Suk ; Lee, Young-Sik ; Lee, Jung-Geun ; Kang, Han-Lim ; Hwang, Myung-Keun
Development of High Efficiency and High Power LED Package for Applying Silicone-Reflector Jeong, Hee-Suk ; Lee, Young-Sik ; Lee, Jung-Geun ; Kang, Han-Lim ; Hwang, Myung-Keun Journal of the Korean Institute of Illuminating and Electrical Installation Engineers, volume 27, issue 9, 2013, Pages 1-5 Abstract
We developed high-efficient 6W-LED package with simple structure by applying Heat Slug and silicone-reflector. LED package was manufactured in sized multi-chip structure having thickness of achieved by bonding silicon-reflector with prepreg on top of the plate after implementing the reflector placed on copper substrate Half Etching by thickness of . The luminous flux, luminous efficacy, correlated color temperature, color rendering index and thermal resistance of developed LED was evaluated, and it verified the application of products by applying it to 120W-LED road luminaires through simulation. The luminous efficacy of LED package reached over 130lm/W, and it is possible to be manufactured into 120W-LED road luminaires using 18 packages. In addition, the simulation results showed average of horizontal illuminance and overall illuminance uniformity that is suitable for three-lane road.
quarta-feira, 20 de agosto de 2014
Hoje, 20 de agosto de 2014, foi divulgado o resultado da Olimpíada Matemática do Cone Sul. A Olimpíada Cone Sul é uma competição internacional da qual países são representados por equipes de 4 estudantes que não tenham feito 16 anos de idade em 31 de dezembro do ano imediatamente anterior à celebração da Olimpíada. A Olimpíada este ano aconteceu no Uruguai.
O resultado brasileiro foi:
Pedro Henrique Sacramento de Oliveira – Ouro
Gabriel Toneatti Vercelli – Ouro
João César Campos Vargas – Prata
Andrey Jhen Shan Chen – Bronze
Parabéns a toda a equipe brasileira!!
PERU PRIMEIRA POSIÇÃO XXV OLIMPIADAS MATEMATICAS CONO SUL URUGUAY
Resultados de la cono sur. Christian Altamirano Modesto (50 puntos) medalla de oro Anthony Huarcaya Palomino (49 puntos) medalla de plata Jemisson Coronel Baldeón (46 puntos) medalla de plata Henry Fabrizio Felen Chavez (40 puntos) medalla de plata Peru (185) quedo primero por paises nuevamente.
CORTESIA DO DISTIGUIDO PROF. MATEMATICAS PERUANO JOHN CUYA
terça-feira, 19 de agosto de 2014
terça-feira, 12 de agosto de 2014
Dynamic Paralleling Behaviors of High Power Trench and Fieldstop IGBTs Yu Wu, Yaojie Sun, and Yandan Lin
LINK FULL PAPER
segunda-feira, 11 de agosto de 2014
"A importância da geração nuclear para se evitar uma crise de energia de base em 2025 no BRASIL" ENG. ANTONIO ERNESTO FERREIRA MULLER
"A importância da geração nuclear para se evitar uma crise de energia de base em 2025"
Segundo o presidente da Associação Brasileira de Engenharia Industrial (Abemi), engº Antonio Ernesto Ferreira Müller, algumas vozes internacionais influentes que sustentam não haver necessidade de se pensar em energia nuclear como alternativa para a geração de eletricidade limpa de base no Brasil – partindo da premissa de que o país tem um grande potencial de instalação de usinas hidrelétricas – estão incorrendo em equívoco por falta de conhecimento da realidade brasileira.
LEIA A INFORMAÇÃO COMPLETA NO SEGUINTE LINK