PROJETO E CONTRUÇÃO DE UM RESTAURADOR DINÂMICO DE TENSÃO MAURICIO GALASSI ENGENHARIA ELETRICA UNIVERSIDADE DE SÃO PAULO BRASIL

PROJETO E CONTRUÇÃO DE UM RESTAURADOR DINÂMICO DE TENSÃO
MAURICIO GALASSI UNIVERSIDADE DE SÃO PAULO BRASIL
DISSERTAÇÃO APRESENTADA A ESCOLA POLITÉCNICA DA UNIVERSIDADE SÃO PAULO
PARA OBTENÇÃO DO TÍTULO DE MESTRE EM ENGENHARIA ELETRICA
LINK
http://www.mediafire.com/view/1w0e5s9n65c17xd/VERSAOFINALT-TESIS_DVR-BRASIL.pdf

Gate Drive Technologies Reinhard Herzer Semikron Elektronik GmbH& CoKG Nuremberg, Germany

LINK
http://www.mediafire.com/view/7ehvrk3olfeh8vf/S1_Documentation_Herzer.pdf

Non-isolated Single Phase Uninterruptible Power Supply (UPS) System Muhammad Aamir Department of Electronics, Electrical, Control, & Instrumentation Engineering Graduate School of Engineering Hanyang University South Korea

( Abstract ) In this thesis, a high performance single phase transformer-less online uninterruptible power supply (UPS) is proposed. The use of the bidirectional buck-boost converter with high conversion ratio not only reduces the number of batteries but also ensures a transformer-less system. The rectifier has capability of power factor correction and provides regulated DC link voltage whereas the inverter provides a regulated sinusoidal output voltage to the load. In order to control the transient effect, efficient control scheme is adopted in the system. The overall efficiency of the system is improved with significant reduction in size and weight of the system due to decrease number of batteries. Qualitative analysis and experimental results obtained with a 500VA prototype shows a normal efficiency of over 94% and an input power factor of over 99%.
LINK
http://www.mediafire.com/view/319sin33r9x19d5/Non-isolated_Single_Phase_Uninterruptible_Power_Supply_(UPS)_System.pdf

Filtering Methods for DC Link Voltage Control of Common-neutral-type Transformerless Single-phase UPS

Filtering Methods for DC Link Voltage Control of Common-neutral-type Transformerless Single-phase UPS 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.
LINK
http://www.mediafire.com/view/2mdbwm62nnxca1r/TRANSFORMER_LESS_UPS.pdf

A study on Development of an algorithm for reducing neutral current in three-phase four-wire PWM rectifier of UPS Kim,SeungHo Dept. of Electrical Engineering Graduate School of Industry and Engineering Seoul National University of Science and Technology

LINK
http://www.mediafire.com/view/biy1liofkhrdmak/dq-based_individual_phase_control_of_three-phase_four-wire_PWM_rectifier_for_UPS.pdf

A Study on the Hybrid UPS with Electrical Energy Storage Function Seung-Beom Lim Department of Electrical Engineering Graduate School, Dankook University

A Study on the Hybrid UPS with Electrical Energy Storage Function

A Study on the Hybrid UPS with
Electrical Energy Storage Function
Seung-Beom Lim
Department of Electrical Engineering
Graduate School, Dankook University
Advisor： Professor Soon-Chan Hong

EES(Electrical Energy Storage) is the system which stores the remaining energy during the time of light load or night time with the cheap electricity price, and then discharges the stored energy during the time of peak load or electric power shortage. This system improves usage efficiency and stabilizes the power supply system. UPS(Uninterruptible Power Supply) can be divided into three parts according to dependency between input and output voltage : Passive-Standby, Line-Interactive, and Double-Conversion. Double- Conversion type UPSs are used to supply the stable power to industrial high-tech/medical equipments and finance/data centers, where loads are sensitive to the blackout and voltage fluctuation. In this paper, it is proposed a double-conversion hybrid UPS with EES function. The proposed hybrid UPS is operating in four states, which are normal state, battery state, bypass state, and EES state. When the AC input source is normal, the system operates in normal state which supplies the stable power to the load through the PFC and inverter, and charges batteries simultaneously. In case of black out or unstable input, the system operates in battery state which supplies the energy from the batteries to the load. In bypass state in case of overload or failure of the inverter, the system supply the input power to the load directly. When the system is needed to operate in EES state, AC input is cut off by the user command and the energy stored in the batteries is supplied to the load. Thereby the system can manage the power efficiently and make the power system more stable. The proposed system is composed of a rectifier, an inverter, a battery charger, and batteries. The rectifier operates as the PFC in normal state and as the battery discharger in battery state and EES state. In the proposed system, there is no battery discharger which is essential in the conventional system. As a natural consequence, the size and weight of the system are reduced. In addition, by designing the inverter as 3-level TNPC(T-type Neutral Point Clamp) inverter, efficiency is improved compared to the conventional 2-level type. To verify the proposed system, it is simulated through the C-block of PSIM. Also, the proposed system with the output rating of 2,700 Watts is constructed and experimented. As a result, it was verified that the proposed system has excellent performances in the viewpoints of efficiency, input power factor, and THDs in input current and output.
LINK
http://www.mediafire.com/view/55llpri0ilp2ock/A_Study_on_the_Hybrid_UPS_with_Electrical_Energy_Storage_Function.pdf

FOTOGRAFIAS PCIM2014 SOUTH AMERICA SÃO PAULO 14-15 OUTUBRO2014

LINK
https://plus.google.com/photos/111424134529259305519/albums/6075043960199981521

XII-5.15.Transformer(2014)

Physics, Class XII Chapter : Alternating current Topic : Transformer, Classroom lecture by Pradeep Kshetrapal. Language : English mixed with Hindi.

Reduction of no-load losses in distribution transformers by using amorphous ribbons Malick MOUHAMAD LME (Laboratoire des Matériels Electriques), Réseau de distribution d'électricité THESE DE DOCTORAT DE L’ECOLE NORMALE SUPERIEURE DE CACHAN

Résumé La présente étude traite l’application des rubans amorphes dans les transformateurs de distribution dans l’objectif de réduire les pertes dans le réseau d’électricité. Les matériaux utilisés sont un alliage à base de fer, silicium et bore. Les premières études sur ce matériau amorphe révèlent une très bonne compatibilité chimique de ces derniers avec les huiles de transformateur. Ces rubans possèdent des durées de vie entièrement conforme aux exigences d’ERDF.
LINK
http://researchers.edf.com/fichiers/fckeditor/Commun/Innovation/theses/TheseMouhamad.pdf

Performance evaluation of amorphous hexa-core for distribution transformers by JOSEFIN ALMÉN & MÅNS BREITHOLTZ

LINK
http://publications.lib.chalmers.se/records/fulltext/167013.pdf