Filtering Methods for DC Link Voltage Control of Common-neutral-type Transformerless Single-phase UPS KIM JI-SU DEPARTAMENT OF ELECTRICAL ENGINEERING GRADUATE SCHOOL KONKUK UNIVERSITY

ABSTRACT

UPS is largely divided into passive-standby, line-interactive, and double-conversion types. Commonly a double-conversion type is used at a site requiring a high reliability. These days, important factors of UPS are high efficiency, low input current distortion, high input power factor, small cabinet size and low price. In this thesis, a common-neutral type transformerless UPS is proposed. A proposed UPS is composed of PFC with 1-switch voltage doubler strategy, half-bridge inverter, separate battery charger and separate battery discharger. PFC with 1-switch voltage doubler strategy and half-bridge inverter are configured as commom-neutral type so that they can convert power without input and output transformer. Therefore input and output transformers can be removed, so the efficiency can be improved and cabinet size can be reduced. Also advantage of PFC with 1-switch voltage doubler strategy and half-bridge inverter is that they need a small number of switching devices so they can simplify driving circuitry and reduce the price. Advantage of separate battery charger and separate battery discharger is that they can make battery voltage lower than DC link voltage so they can reduce the quantity and cost of battery which is an important part of UPS. PI controller was used as voltage controller and current controller of PFC. In order to compensate imbalance of positive and negative DC link voltages, imbalance voltage PI controller was used. In order to compensate leading effect of input current, duty feedforward method was used. Several methods to eliminate 120Hz ripple component in DC voltage feedback were compared with each other. Moving Average resulted in better performance than other methods. Half-bridge was used as inverter circuit. In order to achieve stable static output voltage and improve dynamic characteristic multi-loop control method was used. Finally, the value of proposed UPS was confirmed in the method of simulation and experiment.

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

Study on Management Standards of Total
Harmonics Distortion(THD) measured from UPS
Jeong,Unho
Department of Electrical and Electronic Engineering
Graduate School,Dongshin University
(SupervisorbyProfessor:Ph.D.Kim,Dong-Min)

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 is applied in this paper as
a reference for domestic standards on THD-V limits management.In
recent years,according to integration of KSC standards into IEC,UPS
standards are being revised as KSC IEC 62040,butthere are still no
regulations for THD-V and THD-IaboutUPS causing confusions in
some aspects.
LINK
http://www.mediafire.com/view/1bahx2wgay96n9a/Study_on_Management_Standards_of_Total_Harmonics_Distortion(THD)_measured_from_UPS.pdf

Electronic measurement in nanotechnology and microelectronics Dyakonov V.

Title: Electronic measurement in nanotechnology and microelectronics
Author: Athos AA Dyakonov V.
Publisher: DMK Press
Year: 2011
Pages: 688
Format: PDF
Size: 47.0 MB
ISBN: 50,2
Quality: Excellent

Russia's first monograph on the most advanced electronic and electrical radio measurements and measuring instruments used in research, testing and test equipment and systems, microelectronics and nanotechnology. For the first time in detail the means of measurement applied in a large-scale microelectronic production and instruments leading to their developing and manufacturing firms: Keithley, Tektronix, Agilent Technologies, LeCroy, R & S and others. Particular attention is paid to the analysis and generation of test signals, measurement of their parameters in small and micro time measured by ultra low currents and voltages, impedance analysis and immittance circuits, measurement of static and dynamic characteristics of semiconductor devices and integrated circuits and others. It is the largest survey of contemporary foreign and domestic instruments in the market of Russia and the world. For engineers, scientists, graduate students, teachers and students of universities and technical universities and classical types.
LINK
http://www.mediafire.com/view/80tjucbcmp2mi90/Electronic_measurement_in_nanotechnology_and_microelectronics.pdf

Corto-circuito y selección de equipos eléctricos Kryuchkov IP, Starshinov VA, Gusev YP

Título: Corto-circuito y selección de equipos eléctricos
Autor: Starshinov .
Editorial: MEI
Año: 2012
Páginas: 568
Format: PDF

Corto-circuito y selección de equipos eléctricos - Métodos para el cálculo de cortocircuito, los modos asimétricos simples y complejas en los sistemas de potencia, efectos térmicos y electrodinámicos de las corrientes de cortocircuito en los conductores y dispositivos eléctricos, métodos y formas de limitar las corrientes de cortocircuito, especialmente los cálculos de cortocircuitos en la tensión eléctrica hasta 1 kV.
Instrucciones metódicas para el uso práctico de los dispositivos de protección, así como características de los cálculos de bus rígida de conmutación al aire libre. Un conjunto de programas para el cálculo de corto circuito en un ordenador.
Concebido como un libro de texto para las áreas de formación universitarios 140200 - "Energía Eléctrica" ​​y puede ser utilizado por los expertos, la industria de la energía eléctrica.
LINK
http://www.mediafire.com/view/dil4l6m12w0yno3/Korotkie2012.pdf

COMPENSAÇÃO DA FORMA DE ONDA DE UM INVERSOR PWM UTILIZANDO UMA TÉCNICA DE CONTROLE REPETITIVO Vinícius Cordeiro Durães Araújo Programa de Pós- Graduação em Engenharia Elétrica da Escola de Engenharia da Universidade Federal de Minas Gerais (ENGETRON) BRASIL

COMPENSAÇÃO DA FORMA DE ONDA DE UM INVERSOR PWM
UTILIZANDO UMA TÉCNICA DE CONTROLE REPETITIVO

Vinícius Cordeiro Durães Araújo
Dissertação de Mestrado submetida à Banca Examinadora
designada pelo Colegiado do Programa de Pós-
Graduação em Engenharia Elétrica da Escola de
Engenharia da Universidade Federal de Minas Gerais,
como requisito para obtenção do Título de Mestre em
Engenharia Elétrica.
Orientador: Prof. Porfírio Cabaleiro Cortizo
Belo Horizonte - MG-BRASIL
Universidade Federal de Minas Gerais
Escola de Engenharia
Programa de Pós-Graduação em Engenharia Elétrica

RESUMO
 Os inversores para sistemas UPS devem fornecer uma tensão de saída regulada e com baixo valor de distorção harmônica total (THD - Total harmonic distortion). Este trabalho apresenta um estudo de diversas técnicas de controle para o estágio de saída de um sistema UPS. Foi realizada uma pesquisa bibliográfica de estratégias de controle que contemplam este objetivo. A utilização de uma técnica de controle digital para regular o valor RMS da forma de onda associada com a ação integral repetitiva é avaliada para inversores PWM de baixo custo. Como resultado da ação integral repetitiva, esta estratégia de controle digital reduz o erro de regime permanente e as distorções causada por perturbações periódicas tais como cargas não lineares. Além disso, a técnica de controle digital analisada mede apenas a tensão de saída, reduzindo o custo com SENSORES. O controle repetitivo é uma boa alternativa para as UPS de baixo custo. Ele utiliza a natureza repetitiva das perturbações enquanto os outros métodos não o fazem. O mecanismo de controle é na verdade um controle integral baseado no período fundamental. A tensão de saída é a única variável que deve ser medida, e a ação do controlador principal não precisa ser muito rápida para se alcançar uma forma de onda da tensão de saída com baixa taxa de distorção harmônica total. Apesar de uma resposta sub-cíclica não ser possível, um tempo de assentamento de alguns ciclos do período fundamental é aceitável para muitas aplicações. A Engetron e a excelente equipe do projeto (Mario Henrique, Paulo de Tarso, Wilton Padrão e todos os outros) pelo pleno apoio durante todo o desenvolvimento deste trabalho e incontáveis contribuições
 LINK
http://www.ppgee.ufmg.br/defesas/199M.PDF