Asymmetric Topologies and PWM Modulation Strategy for Low-Cost and High-Quality Single-Phase Multilevel Inverter Choi, Woo-Seok Department of Electrical Engineering Graduate School of Chonnam National University

Asymmetric Topologies and PWM Modulation Strategy for Low-Cost and High-Quality Single-Phase Multilevel Inverter Choi, Woo-Seok Department of Electrical Engineering Graduate School of Chonnam National University (Supervised by Professor : Park, Sung-Jun) 

 (Abstract) Recently, the development of the renewable power industry has been accelerating due to climate change induces to make an effort is the greenhouse gas reduction, and as industrial growth increases the demand for electric power and the electricity generation costs, it has been changing to improve efficiency for power industry structure, and have necessary to develop suitable power converter. Power industry structure has been changing to system minimize demand variation in order to improve grid stability, with low cost. It appears that distributed powers based on renewable power are spreaded over the society at large. In order to fulfill the role of distributed power based on renewable power would be advantageous, using the small size of the distributed power, for grid in stabilized respect. In such cases, many power transmission applications have used the multilevel inverter because the power quality of the renewable distributed power is very important. The multilevel inverter has the advantage of being to generate the output voltage with lower loss and lowr EMC(Electro-Magnetic Compatibility) owing to its low dv/dt stress. The conventional multilevel inverter topologies can include the diode clamped multilevel inverter and flying capacitor multilevel inverter, cascaded multi-cell H-bridge inverter topology. The conventional inverter topologies have a series connection of switch groups, and are usually applied to high power applications with high input/output voltage. However, these topologies have a large increase in the number of switches as the output voltage level increases, and thus are not suitable for the single-phase grid or low voltage applications. The single-phase multilevel topology has the advantage of reducing the number of switches due to lower input/output voltage compared with the conventional multilevel inverter topology. Recently, research into single-phase multilevel inverters has been active as a way to improve power quality. The single-phase multilevel inverter topologies are classified as multilevel inverter based on H-bridge and multilevel inverter based on Half-bridge. This single-phase multilevel inverter based on H-bridge is needed to turn on more than two switches on the one voltage level.
However, the single-phase n-level inverter based on H-bridge is comprised of a smaller number of switches than 2n, and thus a switch is used on more than two output voltage levels.

LINKS
PART1: http://www.mediafire.com/file/ox76ybclip3mphq/SINGLE_PHASE_MULTILEVEL_INVERTER.pdf
PART2 :
http://www.mediafire.com/file/nbqmzi3nas5nkdg/SIMULATION_AND_HARMONIC_ANALYSIS.pdf

IES VIEWER ( PHOTOMETRIC VIEWER )

IESviewer is freeware! The latest release of IESviewer (Version 3.3) is available now!
 IESviewer is the world's most popular photometric viewer. It lets you quickly view, find and convert photometric data files.1 Most of the features present in other viewers are present in IESviewer, including: view photometric curve description of the photometric files luminaire manufacturer luminaire catalog number lamp catalog number lamp description photometric type intensity dimension of luminaire input watts etc Additionally, IESviewer support: unique curve and render realtime thumbnail of photometric files unique navigation by description instead of filename: luminaire manufacturer (MANUFAC) luminaire catalog number (LUMCAT) luminaire description (LUMINAIRE) lamp catalog number (LAMPCAT) lamp description (LAMP) ultra fast preview realtime renderer comparing two photometric curves converting LDT to IES Autodesk 3ds Max integration 3dsmax compatibility indicator and fixing tool available integration with other applications dragging files (copy to explorer, other applications)

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LINK ORIGINAL 
http://www.photometricviewer.com/

OpenCourseWare Electrical Engineering Hanyang University - Seoul, South Korea 전기공학 한양대학교 박관규

1. Transformer의 특성 이해 및 이를 포함한 회로의 해석

A Study on High Quality Single-Phase Seven-Level Grid-Connected Inverter Department of Electrical Engineering Graduate School, Chonnam National University - Le Tuan Vu

(Abstract)
Multilevel inverter technology has emerged recently as a very important alternative in the area of high-power medium-voltage energy control. Multilevel inverters include an array of power semiconductors and capacitor voltage sources, the output of which generate voltages with stepped waveforms. The commutation of the switches permits the addition of the capacitor voltages, which reach high voltage at the output, while the power semiconductors must withstand only reduced voltages. There are three commonly topologies have been proposed for multilevel inverters: diode-clamped (neutralclamped); capacitor-clamped (flying capacitors); and cascaded multicell with separate dc sources. The most attractive features of multilevel inverters are that they can generate output voltages with extremely low distortion, they draw input current with very low distortion and they can operate with a lower switching frequency.
LINK
http://www.mediafire.com/file/4c4wv4gq7t47141/HIGH_QUALITY_SINGLE_PHASE_SEVEN_LEVEL.pdf

A Study of High Resolution Isolated Multi-Level Inverter for Grid-Tie Renewable Generation System by Noh Sik Park Department of Mechatronics Engineering The Graduate School Pukyong National University

A Study of High Resolution Isolated Multi-Level Inverter for Grid-Tie Renewable Generation System 신재생 발전 시스템의 계통 연계를 위한 고정도 절연형 멀티레벨 인버터에 관한 연구 
Advisor: Prof. Soon Jae Kwon 
by Noh Sik Park 
A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Department of Mechatronics Engineering
The Graduate School Pukyong National University February 2009
 ABSTRACT 
 The objective of this paper is to contribute to the commercialization of high resolution 3 phase multi level inverter that uses new control method which is properto thegreatcapacity inverter used for Grid-tiedRenewable GenerationSystem.Forthispurpose,thebasicoperationprincipleandtypes of the conventional multi level inverter is divided to describe the each merit and demerit, the modulation technique applicable to multi level inverter, the domestic and overseas standard and protecting technology of grid-tied technology which is indispensable to grid-tied inverter. The loss for each factor in 3 phase multi level inverter that uses low-frequency transformer was analyzed with structure of 3 phase multi level, theoretic investigationontheregularspacevectormodulationmethodandanewcontrol technique so as to calculate all loss that may occur in the proposed inverter. Further, this research explained the control technique applied to anti-islanding, an essential function of grid-tied inverter and confirmed outputwaveformandTHDforeachrateofmodulationbyusingMatrap/Simulink so as to check the technical feasibility of multi level inverter using 3 phase low-frequency transformer. As 3 phase multi level inverter in 30kW isolate type was designed, produced and experimented, it was confirmed that the performance which was not inferior to that of the existing 2 level inverter method was embodied. Since there is no particular difficulty in productioncomparedtotheexistingproductswhichareproducedbydepending on many know-hows and less part was technically restricted in producing inverter with capacity larger thanthatof inverter produced forresearch, it presents the possibility of localizing power transformer for Grid-tied RenewableGenerationSystemwhichgetslarger
LINK
http://www.mediafire.com/file/vqs3pl4rkq4ezao/A_Study_of_High_Resolution_Isolated_Multi-Level_Inverter_for_Grid-Tied_Renewable_Generation_System.pdf

Analyse des contraintes mecaniques par la methode des elements finis dans une machine electrique - Mechanical Stress Analysis by the Finite Elements Method in Electric Motor CHANG- HOON JUN Thesis(doctoral)-- L'ecole centrale de Lyon-Genie electrique

Analyse des contraintes mecaniques par la methode des elements finis dans une machine electrique - Mechanical Stress Analysis by the Finite Elements Method in Electric Motor CHANG- HOON JUN Thesis(doctoral)-- L'ecole centrale de Lyon: Genie electrique 1998
 LINK
http://www.mediafire.com/file/szn14jrp6xsl916/09590683.pdf

BREAKDOWN VOLTAGE PERFORMANCES OF ALUMINUM AND COPPER CONDUCTOR WIRE UNDER COMPRESSION STRESSES -Richard Donald Suchanek - Western Kentucky University Master of Science

BREAKDOWN VOLTAGE PERFORMANCES OF ALUMINUM AND COPPER CONDUCTOR WIRE UNDER COMPRESSION STRESSES 

A Thesis Presented to The Faculty of the Department of Architectural and Manufacturing Sciences Western Kentucky University Bowling Green, Kentucky
 In Partial Fulfillment Of the Requirements for the Degree Master of Science By Rich Suchanek
May 2016
 ABSTRACT
 In the global, competitive market of energy transformation, increased operational expenses and depletion of raw materials have resulted in companies pursuing alternate materials to reduce consumer costs. In electrical applications, energy is transformed using materials with high electrical conductive properties. The conductive material used to transmit a signal is called conductor wire and is comprised of any material that has the ability to move charged particles from one point to another without propagation or delay. The conductor wire in many applications is encapsulated in epoxy resin called enamel. The enamel is the insulation system that provides necessary dielectric clearances to prevent voltage leakage. The most common form of energy transformation is the electric motor. Both copper and aluminum conductor wire are commonly used in electric motors, but copper is preferred due to thermal and electrical properties. However, there is a significant economic incentive to convert to aluminum conductor wire. Limited white papers are available comparing the performances of the two materials; the research is limited to physical and electrical performances of the raw material and does not take into considering the insulation. The conductor wire, which includes the insulation, is susceptible to damage during the manufacturing process and is an inherent risk if not fully understood. During the blocking process, the conductor wire is pushed and compressed into lamination slots. This process changes the conductor wire outer diameter to accommodate void spaces within the lamination slots. The percentage of slot vii area occupied by the conductor wire is known as slot fill. The higher the slot fill, the more wire occupying the available space. The higher the slot fill, the more force required to fill the slots. High slot fill motor designs provide a performance advantage with little associated cost. The more wire pressed into the slot, the higher the potential efficiency gains. However, high slot fill motors are more susceptible to damage. The study is designed to evaluate and measure the durability of aluminum and copper conductor wire under simulated compression stresses. Utilizing this information, electric motor manufacturers can push current design limits without affecting conductor wire quality and reliability.
FULL THESIS LINK ORIGINAL:
http://digitalcommons.wku.edu/cgi/viewcontent.cgi?article=2611&context=theses

直播回放: 神舟十一号与天宫二号交会对接, 航天员进入天宫二号 | Full Replay: Shenzhou 11 Spacecraft Dock With Tiangong 2 Space Lab

LINK
https://youtu.be/jKvZmmUfLSo

Live: Chinese astronauts enter Tiangong-2 space lab from Shenzhou-11 spacecraft

China's manned spacecraft, Shenzhou-11, docks with space lab Tiangong-2. The spacecraft was launched into orbit on Monday, carrying two astronauts who plan to stay in the space lab for 30 days. The crewed mission marks a key step toward China's plan to eventually operate a permanent space station.

ARC FLASH HAZARDS ANALYSIS by ZHENYUAN ZHANG Graduate School of The University of Texas at Arlington 2015

ARC FLASH HAZARDS ANALYSIS by ZHENYUAN ZHANG

Presented to the Faculty of the Graduate School of The University of Texas at Arlington in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY THE UNIVERSITY OF TEXAS AT ARLINGTON


Abstract 
ARC FLASH HAZARDS ANALYSIS Zhenyuan Zhang, PhD The University of Texas at Arlington, 2015
 Supervising Professor: Wei-Jen Lee

 Annually more than 2000 workers are admitted to hospital burn centers for extensive injuries caused by arc flash accidents. Arc flash incidents occur when unintended electric current flows through air, superheating the air and causes an explosion. Recognizing the significant threat posed by arc flash hazards, IEEE and NFPA have joined forces on an initiative to support research and additional testing to increase the understanding of the arc flash phenomena. Accurately represent all the real applications for arc flash events are very difficult, not only because of their random complex nature, but also because a large number of uncertain variables involved. Several areas of the arc flash phenomena need further research and testing validation. In order to have a precise arc flash hazards assessment, approximately 2000 arc flash experiments had been conducted, which are crossed extensive range of system voltage, bolted fault current, electrodes gap width, arc initiative configuration and enclosure dimensions. This dissertation has reviewed the testing methodology, test equipment design and modeling process for arc flash hazards analysis. The research and testing focused on, but will not be limited to (a) the development of physics and engineering-based modeling for arc flash thermal hazards, and (b) design and testing for non-thermal hazards, such as light, pressure and sound. Based on the works of the dissertation, sets of assessment equations and approaches have been proposed for arc flash thermal and non-thermal hazard analysis. The results of this dissertation will provide information to help more accurately predict the hazards associated with high energy arcing faults, thereby improving electrical safety standards and providing practical safeguards for employees in the work place.

LINK ORIGINAL
https://uta-ir.tdl.org/uta-ir/bitstream/handle/10106/25513/ZHANG-DISSERTATION-2015.pdf?sequence=1
LINK ALTERNATIVO
http://www.mediafire.com/file/2wbqqd7064st7ei/ZHANG-DISSERTATION-2015.pdf