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”

quinta-feira, 21 de janeiro de 2016

A Study on Management Standards of Total Harmonics Distortion(THD)measured from UPS - Jeong,Unho Department of Electrical and ElectronicEngineering Graduate School,Dongshin University


The purpose of this paper is to describe UPS(Uninterruptible Power Supply) in a comprehensive measure THD(Total Harmonic Distortion) and compared with domestic and international management standards in harmonics, harmonics reduction measures by analyzing the appropriate UPS technology. Harmonics generated by the UPS. measurements of national standards was confirmed appropriate, UPS comprehensive harmonic currents measured range THD-I limits for national standards, the reference by KSC 4310, THD-V for domestic not based on the site was confirmed. Therefore,The IEEE(Institute of   Electrical and Electronics Engineers)Std.519 i applied in this paper as a reference for domestic standards on THD-V limits management.In recent years,according to integration of KSC standards in to IEC,UPS standards are being revised as KSC IEC 62040,but there are still no regulations for THD-V and THD-Iabout UPS causing confusions in some aspects.Accordingly,in the KSC IEC management standards to be amended which are related to UPS,I consider the introduction of the integrated regulatory limits on THD-V andTHD-I which are currently mixed to be very urgent. Therefore In this paper, we measured the THD-I and THD-V for UPS domestic and international management standards and harmonic comparison and analysis results were as follows.
LINK
http://www.mediafire.com/view/zfro9hz339iatjb/A_Study_on_Management_Standards_of_Total_Harmonic_Distortion%28THD%29_measured_from_UPS.pdf

A Study on the Heat Flow Inside UPS according to the Outside Temperature -Dong – Min Kim Department of Mechanical Engineering, The Graduate School Konyang University Nonsan Chungnam Korea



Dong – Min Kim Department of Mechanical Engineering, The Graduate School Konyang University Nonsan Chungnam Korea

 UPS is an electrical apparatus that provides emergency power to a load when the input power source, typically mains power, fails. When installing UPS in outdoors (a road near or mountain, etc..), it is also possible many problems according to the outdoor environment. And it is possible generate condensation by a temperature difference The purpose of this study was to predict the inner temperature of UPS and to prevent dew condensation in UPS by simulating the heat flow using ANSYS. So in this study, The inner heat flow simulations for UPS were conducted by the Computation Fluid Dynamics Analysis, ANSYS, during the active state of UPS. Compared with Air temperature, Relative humidity, Inner temperature of UPS to be found that condensation is occurring. It’s can be improved by ventilation or insulation effectively inside UPS according to this simulation result.
LINK
http://www.mediafire.com/view/64sm02hh5f7f4ob/A_Study_on_the_Heat_Flow_Inside_UPS_according_to_the_Outside_Temperature.pdf

quinta-feira, 7 de janeiro de 2016

Short-circuit and selection of electrical equipment Kryuchkov - Короткие замыкания и выбор электрооборудования Крючков И.П.



Short-circuit and selection of electrical equipment Kryuchkov - Короткие замыкания и выбор электрооборудования Крючков И.П.
The methods for calculating short circuits, simple and complex asymmetrical modes in power systems, thermal and electrodynamic effects short circuit currents in the conductors and electrical equipment, methods and techniques for limiting short-circuit currents, especially the calculations of short circuits in the electrical voltage up to 1 kV.
LINK ORIGINAL EN LA WEB FORMATO DJVU
http://mexalib.com/download/35812

LINK ALTERNATIVO FORMATO PDF

sábado, 26 de dezembro de 2015

A Novel Single-Phase Cascaded Multilevel AC-AC Converter Without Commutation Problem Kim, Sang-hun Department of Electrical Engineering Graduate School, Kyungpook National University Daegu, Korea









Abstract)
 This paper presents a novel cascaded multilevel PWM ac-ac converter that can solve commutation problem. By cascading the single-phase PWM ac-ac converter that uses basic switching cell structure and coupled inductors, the proposed converter does not need to sense the voltage or current polarity for safe commutation. When many unit-cells are cascaded, the proposed converter has more output voltage levels and can obtain high ac output voltage by using low voltage rating switching devices. By applying phase-shifted PWM technique, the proposed converter can reduce output filter size significantly. A 2 kW prototype converter having four unit-cell structure is built and tested to verify the performance. *

LINK
http://www.mediafire.com/view/8p898ucoid8uf3b/CONVERTER_AC-AC-2015.pdf

quinta-feira, 24 de dezembro de 2015

A VOLTAGE SAG SUPPORTER UTILIZING A PWM-SWITCHED AUTOTRANSFORMER A Thesis Presented to The Academic Faculty by Dong-Myung Lee School of Electrical & Computer Engineering Georgia Institute of Technology Atlanta




INTRODUCTION
1.1 Background A power distribution system is similar to a vast network of rivers. It is important to remove any system faults so that the rest of the power distribution service is not interrupted or damaged. When a fault occurs somewhere in a power distribution system, the voltage is affected throughout the power system. Among various power quality problems, the majority of events are associated with either a voltage sag or a voltage swell, and they often cause serious power interruptions. A voltage sag condition implies that the voltage on one or more phases drops below the specified tolerance for a short period of time. A voltage swell condition occurs when the voltage of one or more phases rises above the specified tolerance for a short period of time. The causes of voltage sags and swells are associated with faults within the power distribution system. Users located a close distance to the fault experience voltage sags much greater in magnitude and duration than users located farther away, and as the power distribution system have power interruptions during a fault because of the effects of a voltage sag or voltage swell produced in the system by the fault. The objective of this research is to develop a novel voltage control scheme that can compensate for voltage sag and swell conditions in three-phase power systems.

LINK
ttp://www.mediafire.com/view/j1wv1l6fu2p57fb/ESTABILIZADOR_AC-KOREA-2015.pdf

sábado, 5 de dezembro de 2015

COBEP2015 FORTALEZA CEARA BRASIL TUTORIAL DR. CUK





Power Electronics: A New Beginning By Slobodan Ćuk, TESLAco
Power Electronics progress depends on the progress in its two constituent areas: System Technology and Power Management Technology, which had been traditionally developed in the past in companies specializing in either one or the other area of expertise. System Technology companies, or Power Supply companies relied heavily on the use of the components (switches, drive and control circuits) developed by Power Management companies.
The System Technology popularly known as converter topologies has changed very little in last 50 years and is, in fact, the key reason why the Power Electronics as whole has progressed much less despite the tremendous advances made by Power Management companies in developing the new switching devices with ever increasing switching devices power and speed improvements and high performance digital control circuits.
The conventional topologies are analyzed and the sources of their deficiencies are established. This, in turns, leads to the new switching methods and the corresponding novel switching converter topologies which are overcoming all these deficiencies. However, no incremental change will do, but a fresh new look is needed. Hence what is needed is: Power Electronics: A New Beginning!
Dr. Slobodan Ćuk
Dr. Ćuk received his bachelor degree from Belgrade University, Yugoslavia, 1970, MSEE degree from University of Santa Clara, USA 1974 and her Ph.D. from Caltech, California , USA, 1976.
Dr. Ćuk was the full-time Professor of Electrical Engineering at the California Institute of Technology until January 1, 2000 where he conducted research and taught courses in Power Electronics and Fundamentals of Energy Processing. During his 25 years at Caltech, more than 35 students obtained Ph.D. degree in Power Electronics under his guidance. More than dozen of his former students are Professors of Power Electronics in U.S. and abroad while others are leading researchers in the industry.
For the invention of Integrated Magnetics Dr. Ćuk obtained a 1991 Edward Longstreth Medal from Franklin Institute which was for the first time in its 100 years history awarded to researchers in Power Electronics. His publications include over 100 scientific papers in the Power Electronics field and a three-volume book on Switched-Mode Power Conversion.
Over a span of 20 years, Dr. Ćuk has taught a number of public and in-house courses in United States, Europe and Far East, which were attended by over 4,000 Power Electronics specialists. In 1979, Dr. Ćuk founded TESLAco. He holds over 20 patents in switching power conversion filed. Over dozen patents on Ćuk Optimum Power Conversion technology are pending or are currently in preparation.
Dr. Ćuk’s Inventions and Discoveries
1. Optimum Topology Converter, known as the ĆUKconverter (1974)
2. Coupled-Inductor and Integrated Magnetics method (1975)
3. State-space averaging method (1975)
4. TESLAconverter (2000)
5. Hybrid-switching and Storageless-Switching Method (2009)
6. New DC-DC and Bridgeless AC-DC converter topologies (2010):