A Study of UPS System Using Integrated Source Transfer Switch Method Yong-UkKim Department of Electrical Engineering Graduate School of Industry Pukyong National University

Abstract - Single UPS operation of a plurality of such parallel d related research is going.UPS voltage/constant-frequency supply capacity of STS and multiple UPS parallel operation of the problems caused
due to the combination of transfer function of an uninterruptible power neutrali zing SYSTEM propose a way of switching from traditional asynchronous state on the benefits and Radish only transfer the problems caused by five manual operation of an asynchronous operation and SCR switching behavior is studied.
LINK
http://www.mediafire.com/view/q4mvxqxb3omvic0/STS-UPS.pdf

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

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

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