AUTOR DO BLOG ENG.ARMANDO CAVERO MIRANDA SÃO PAULO BRASIL

"OBRIGADO DEUS PELA VIDA,PELA MINHA FAMILIA,PELO TRABALHO,PELO PÃO DE CADA DIA,PROTEGENOS DO MAL"

"OBRIGADO DEUS PELA VIDA,PELA MINHA FAMILIA,PELO TRABALHO,PELO PÃO DE CADA DIA,PROTEGENOS  DO MAL"

“SE SEUS PROJETOS FOREM PARA UM ANO,SEMEIE O GRÂO.SE FOREM PARA DEZ ANOS,PLANTE UMA ÁRVORE.SE FOREM PARA CEM ANOS,EDUQUE O POVO.”

“Sixty years ago I knew everything; now I know nothing; education is a progressive discovery of our own ignorance. Will Durant”

https://picasion.com/
https://picasion.com/

segunda-feira, 14 de novembro de 2016

Triplen Harmonics Mitigation 3 Phase Four-Wire Electrical Distribution System Using Wye- Zig-Zag Transformers Rosli Omar, Azhar Ahmad and Marizan Sulaiman Faculty of Electrical Engineering, Universiti Teknikal Malaysia Melaka



This paper studies an application of wye- zigzag transformes for reducing harmonics in the neutral conductors of a three phase 415/240V distribution system. Triplen harmonic currents add up in the neutral conductor of the distribution system feeding the non linear loads such as personal computers and electronic office machines with switch mode power supplies. The zigzag transformer is installed between the distribution panel and the high harmonics producing loads. This research makes use of a star-zigzag grounded transformer.

 LINK ORIGINAL
http://jeteas.scholarlinkresearch.com/articles/TRIPLEN%20HARMONIC%20MITIGATION.pdf

Winding Method of Transformer for Zero-Sequence and Negative-Sequence Harmonic Elimination Kim, Tae-Hoon; Park, Jun-Yeal - 영상분 및 역상분 고조파 제거를 위한 변압기 결선방식






영상분 및 역상분 고조파 제거를 위한 변압기 결선방식 Winding Method of Transformer for Zero-Sequence and Negative-Sequence Harmonic Elimination 김 태 훈*․박 준 열† (Tae-Hoon Kim․Jun-Yeal Park) 

 Abstract
As the various kinds of load who generate higher harmonics increases according as the power electronics technology develops, harmonic treatment standard is proposed by IEEE and IEC. Because establishment of harmonic reduction device is required for existent installment to satisfy harmonic treatment standard, the problem of investment charge and installation space increasing may be occurred. In order to solve these problems, a novel transformer connection method using principles of PCT and ZED is suggested.

ISSN 1975-8359(Print) / ISSN 2287-4364(Online)
The Transactions of the Korean Institute of Electrical Engineers Vol. 63, No. 7, pp. 896~902, 2014
http://dx.doi.org/10.5370/KIEE.2014.63.7.896

LINK ORIGINAL FULL PAPER
http://ocean.kisti.re.kr/downfile/volume/kiee/DHJGII/2014/v63n7/DHJGII_2014_v63n7_896.pdf

sábado, 12 de novembro de 2016

Счетчики и регистры сдвига - Counters and shift registers-Anatoly Leonidovich Larin



О лекции Счетчик. Вычитающий счетчик и реверсивный счетчик. Временные задержки в счетчиках с последовательным переносом. Счетчик по произвольному модулю. Счетчик по произвольному модулю. Лекторы Ларин Анатолий Леонидович кандидат технических наук, доцент кафедры радиотехники МФТИ

Counters and shift registers
Anatoly Leonidovich Larin
Ph.D., Associate Professor, Department of Radio Engineering MIPT
Московский физико-технический институт

quinta-feira, 10 de novembro de 2016

Power Conversion Technology for Grid-connected PV Inverter-WOO-JUN CHA -DOCTORAL THESIS-DEPARTMENT OF ELECTRICAL ENGINEERING POHANG UNIVERSITY OF SCIENCE AND TECHNOLOGY-SOUTH KOREA



ABSTRACT
This thesis proposes hardware circuits and control algorithm of grid-connected photovoltaic (PV) inverters having high efficiency. PV inverter can be classified into singlephase and three-phase inverter according to power capacity. A micro-inverter system is proposed for the single-phase inverter. This system is composed of step-up dc-dc converter that uses an active-clamp circuit with a series-resonant voltage doubler and a high efficiency inverter with single-switch-modulation. During the step-up dc-dc stage, the active-clamp circuit provides zero-voltage switching turn-on, recycles the energy stored in the leakage inductance of the transformer, and limits switch voltage stress. A series-resonant voltage doubler is used on the transformer secondary side to remove the reverse-recovery problem of the rectifier diodes. During the inverter stage, to improve efficiency and reliability in the proposed inverter, only single switch is modulated at switching frequency without shoot-through problem. This whole process minimizes power losses and eliminates a mismatch of a capacity between the PV panel and PV inverter, so the proposed micro-inverter is suitable for use in a single-phase grid connected PV inverter. A prototype design and experimental results are given to verify the proposed system. A novel space-vector modulation (SVM) for a three-phase PV inverter with simple software implementation is proposed. The conventional SVM algorithm for the three-phase PV inverter requires complex computations, such as square root and arctangent, and a sector selection algorithm. The proposed SVM algorithm can determine directly on-state times of switches without complex computations and complex sector selection algorithm. Experimental results show high performance of the proposed algorithm for the three-phase PV inverter.