A Study on Control and Grid Synchronization for a Threephase Grid-connected Inverter in Distributed Generation Systems - Lai Ngoc Bao -Dept. of Electrical and Information Engineering The Graduate School Seoul National University of Science and Technology

Abstract
A Study on Control and Grid Synchronization for a Three-phase Gridconnected Inverter in Distributed Generation Systems Lai Ngoc Bao (Supervisor Kim, Kyeong-Hwa) Dept. of Electrical and Information Engineering The Graduate School Seoul National University of Science and Technology

This thesis presents an improved current control strategy for a three-phase grid-connected inverter under distorted grid conditions. The primary challenge associated with the gridconnected inverter in distributed generation (DG) systems is to maintain the harmonic contents in output current below the specified values even when the grid is subject to uncertain disturbances such as harmonic distortion. To address such a challenge, an improved current control scheme is proposed for a grid-connected inverter, in which the fundamental and harmonic currents are independently controlled by a PI decoupling controller and a predictive basis controller, respectively. The controller design approach is based on the model decomposition principle, where the measured inverter currents and grid voltages are split into the fundamental and harmonic currents using moving average filters (MAFs). Furthermore, to detect the grid angular displacement and frequency with better accuracy even in the presence of the grid voltage disturbances, the MAF is also introduced to construct an enhanced phase-lock loop (PLL) scheme. Theoretical analyses as well as comparative simulations results prove that the proposed control scheme adequately compensates the abnormalities caused by the grid voltage disturbances with fast transient response. To validate the feasibility of the proposed control scheme, the iientire control algorithm is implemented on a 2 kVA three-phase grid-connected inverter system using 32-bit floating-point DSP TMS320F28335. As a result, the proposed scheme is an attractive way to control a grid-connected inverter under adverse grid conditions.

LINK
http://www.mediafire.com/file/6bwc5529rb2b24u/grid.pdf

Leakage Inductance Determination for Transformers with Interleaving of Windings R. Doebbelin and A. Lindemann Institute of Electric Power Systems, Otto-von-Guericke-University Magdeburg, Germany

Leakage Inductance Determination for Transformers with
Interleaving of Windings
R. Doebbelin and A. Lindemann
Institute of Electric Power Systems, Otto-von-Guericke-University Magdeburg, Germany

Abstract| A diversity of formulas is given in literature for leakage inductance calculation
of transformers with interleaving of windings. In the paper, the meaning of included terms and
details of the application for concentric and pie windings transformers shall be discussed. Consid-
ering the limitation of common formulas to magnetically symmetric transformers an alternative
approach shall be demonstrated, which enables leakage inductance prediction also in the case of
transformers with magnetically asymmetric arrangements of windings.

LINK VIEW FULL TEXT:
ttp://www.mediafire.com/file/m116cldykkbcvqc/Vol6No6Page527to531.pdf

NO-BREAK SOLAR OFF-GRID HIBRIDO LANÇAMENTO NA EXPOSEC 2017 SÃO PAULO BRASIL

NO-BREAK SOLAR OFF-GRID HIBRIDO 5.000 À 10.000W

Potências: 5.000 a 10.000W

Alta confiabilidade: Controle microprocessado DSP, combinando tecnologia SPWM e chaveamento de potência em alta frequência
Modo de operação selecionável: Prioridade armazenamento ou fornecimento de energia Prevenção de danos: por atenuação PID garantindo a vida útil plena dos painéis fotovoltaicos
 Gerenciamento de baterias: Carregador com três estágios, reduzindo o tempo de recarga e protegendo contra descarga profundal de baterias
Alimentação: AC: com sincronismo on-line, minimizando o tempo de transfência garantindo o fornecimento de energia à carga
Seleção automática: de frequência (60/50Hz)
Comunicação inteligente: RS232 ou USB (SNMP opcional)

Peruanos crean minisatélite y ganan premio en Francia-ESTUDIANTES DE LA UNIVERSIDAD NACIONAL DE INGENIERIA LIMA PERU

SEMIKRON - REVISTA POTÊNCIA Webinar gratuito: Como definir seus semicondutores de potência 22 AGOSTO 7:PM

No dia 22 de agosto acontecerá o primeiro webinar da parceria entre a empresa SEMIKRON e a Revista Potência, o tema escolhido é "Como definir seus semicondutores de potência". Esse webinar contará com três especialistas da SEMIKRON: - Eng. Fábio Miura - Eng. Maurício Falsetti - Eng. Ricardo Prado Data: 22 de agosto Horário: 19h00 Inscreva-se gratuitamente: 

https://lnkd.in/ezMYbHZ

Magnetic and Electric Characterization of Materials for Electrical Machines by M.S.Muhit -Royal Institute of Technology School of Electrical Engineering Electrical Machines and Power Electronics

Magnetic and Electric Characterization of Materials for Electrical Machines 
by M.S.Muhit
 Master Thesis
Royal Institute of Technology School of Electrical Engineering Electrical Machines and Power Electronics Stockholm, August 2011
 Abstract
This thesis aims to characterize materials for electrical machines. Electromagnetic properties (b-h curves) and electrical resistivity were the main properties investigated in the project work. Two types of samples are considered: stator lamination sheet and rings made of steel used for structural pieces in large AC machines. To facilitate magnetic characterization experiments, an existing test setup was upgraded. Sensors and amplifiers have been developed. The control system has been upgraded and developed SIMULINK modules have been adapted to dSPACE GUI. The retrieved ‘B’ and ‘H’ signals are processed offline to obtain the results. The lamination sheet has been tested for frequencies in the range [0.1-150 Hz] and flux density levels up to 1.5 T. The obtained results depict characteristics hysteresis curves and measured loss figures. The ring samples (structural steel) are characterized to explore the B-H curves at frequencies in the range [0.1-250 Hz] and field intensity up to 900 A/m. For resistivity measurements of the lamination sheets and ring samples, standard resistivity measurement techniques have been implemented. Keywords Magnetic properties, Epstein frame, hysteresisgraph, four point probe, resistivity measurement, soft magnetic material, electrical steel.
VIEW FULL TEXT
http://www.diva-portal.org/smash/get/diva2:470656/fulltext01

Measurement research on magnetic properties of electrical sheet steel under different temperature, harmonic and dc bias Dezhi Chen - Li wei Fang - Byung-il Kwon School of Electrical Engineering, Shenyang University of Technology

Measurement research on magnetic properties of electrical
sheet steel under different temperature, harmonic
and dc bias
Dezhi Chen - Li wei Fang - Byung-il Kwon
School of Electrical Engineering, Shenyang University of Technology,
 Shenyang, China


I. INTRODUCTION 
The phenomena such as the DC power grid, geomagnetic storms change, DC voltage of converter transformer may result in DC bias. Then the DC bias leads to the magnetic leakage flux increase in cores, metal structure losses, temperature rise, local overheating, dielectric breakdown, noise vibration, even the permanent damage to transformer.1 Meanwhile, the rise of temperature and harmonic will also affect the magnetic properties of electrical sheet steel. Manufacturers of electrical sheet steel can provide magnetic parameters, such as loss of iron core, that usually are measured at room environment temperature. The measured electromagnetic performance of transformer has a certain error compared with the actual operation temperature.2 When temperature, harmonic and DC bias change at the same time, the transformer operation condition will be more complicated. This paper is the first time to present the measurement research on the magnetic properties of oriented electrical sheet steel considering both different temperature and DC bias, and it shows the curve of magnetic properties under different temperatures (40 °C to 150 °C), frequency(50Hz to 4.5kHz) and DC bias (0A to 2.0A). It can provide a useful guidance for the design and optimization of power transformer

LINK ORIGINAL
http://aip.scitation.org/doi/pdf/10.1063/1.4979490

Hybrid DC/DC Converter for Electric Vehicle (EV) On-Board Charger (OBC) Using Full-Bridge (FB) and Resonant Converter with Single Transformer -Department of Electrical Engineering Myongji University Seoul Korea

ABSTRACT In this document a highly efficient hybrid DC/DC converter is proposed. Its design procedure, analysis and experimental results are presented by testing of the implemented prototype and. whole document is arranged into six chapters. Electrical vehicle battery chargers background, power level, different charging methods and purpose of the document is presented in chapter 1. High power DC/DC converter topologies suggested recently, and its benefits and drawbacks are briefly discussed in chapter 2. Proposed converter diagram, operational analysis and comparison of proposed converter with other DC/DC converter topologies are presented in chapter 3. Chapter 4 is about design procedure. Based on the design procedure suggested in chapter 4, prototype design and simulation results are given in chapter 5 and experimental results are given in chapter 6. Most of the previously proposed hybrid converters have used two transformers for each converter in hybrid structure that makes the size of the converter bulky and there was also low utilization and the power distribution problem between two transformers of the hybrid converters. To solve this problem, a new high efficient hybrid DC/DC converters using single transformer, which has characteristics of Full-bridge and resonant convertor for EV OBC, is proposed in this thesis. By using single transformer the power distribution problem has been solved and transformer utilization has become high. In the proposed converter, magnetizing inductance has been used at the primary side of the transformer to obtain the soft switching such as zero voltage switching (ZVS). Leakage inductance of the transformer has been used as resonant inductor on the secondary side to avoid the use of separate inductor as resonant. The prototype of 6.6KW has been implemented to verify the feasibility of the proposed converter and maximum efficiency of 97.4 is achieved at 413 V.

This paper proposes a dc/dc converter for electric vehicle onboard chargers using a secondary resonant tank. To attain soft switching characteristics, such as zero voltage switching, magnetizing inductance has been used at the primary side of the transformer. The leakage inductance of the transformer is used as a resonant inductor on the secondary side to avoid the use of a separate inductor as resonance. The proposed converter is applicable for a wide load range. A 6.6KW prototype has been implemented for a wide range of load variations (250V, 330V, 360V, and 413V). A maximum efficiency of 97.4% is achieved at 413V.

 LINK VIEW FULL TEXT
http://manuscript.jpe.or.kr/ltkPSWeb/pub/pubfpfile.aspx?ppseq=1333

LINK :  http://www.mediafire.com/file/j3todp7qifgn64c/2_JPE-16-06-032.pdf

FLUKE - Segurança em Medições Elétricas

Digital Control of Bidirectional LLC Resonant Converters* Minjun Park Electronics Engineering, Kyungpook National University, Taegu, South Korea

Digital Control of Bidirectional LLC Resonant Converters* Minjun Park Graduate School of Electronics Engineering, Graduate School, Kyungpook National University, Taegu, South Korea (Supervised by Professor Byungcho Choi)

 (Abstract)
This thesis presents the dynamic analysis and compensator design of digitally controlled bidirectional LLC resonant dc-to-dc converter. The digital control scheme employs an additional A/D feedback from the current and voltage of the resonant tank network to overcome the limitation of the existing analog control. The superiority of the digital control over the analog control is verified using an experimental 300 W bidirectional LLC resonant dc-to-dc converter. The digital compensator is designed by emulation approach using bilinear transform. Both of the controllers are verified using PSIM simulation and experimental of prototype hardware.
* A thesis submitted to the Council of the Graduate School of Kyungpook National University in partial fulfillment of the requirements for the degree of Master of Science in December 2013