"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”
segunda-feira, 22 de junho de 2015
Curso Básico de Física Aula 12 Circuitos 2 - Vanderlei Bagnato - IFSC USP
Eletricidade e Magnetismo - Aulas Gravadas em 2002 -
Instituto de Física de São Carlos - USP-UNIVERSIDADE DE SÃO PAULO - BRASIL
Curso Básico de Física Aula 12 Circuitos 2
Aulas Ministradas pelo Prof. Dr. Vanderlei Bag
The Development of High-Current Power Supply System for Electrolytic Copper Foil An Luo, Fujun Ma, Qiaopo Xiong, and Zhixing He - Research Institute, China Shipbuilding Industry Corporation (CSIC), Wuhan, China
Abstract
A 6.5 V/50 kA high-frequency switching power supply (HSPS) system composed of 10 power modules is developed to meetthe requirements of copper-foil electrolysis. The power module is composed of a two-leg pulse width modulation (PWM)rectifier and a DC/DC converter. The DC/DC converter adopts two full-wave rectifiers in parallel to enhance the output. For thetwo-leg PWM rectifier, the ripple of the DC-link voltage is derived. A composite control method with a ripple filter is thenproposed to effectively improve the performance of the rectifier. To meet the process demand of copper-foil electrolysis, thevirtual impedance-based current-sharing control method with load current full feedforward is proposed for n-parallel DC/DCconverters. The roles of load current feedforward and virtual impedance are analyzed, and the current-sharing control model ofthe HSPS system is derived. Virtual impedance is used to adjust the current-sharing impedance without changing the equivalentoutput impedance, which can effectively reduce current-sharing errors. Finally, simulation and experimental results verify thestructure and control method.
LINK ORIGINAL
http://www.jpe.or.kr/archives/view_articles.asp?seq=984
LINK DIRECT
http://manuscript.jpe.or.kr/ltkPSWeb/pub/pubfpfile.aspx?ppseq=984
Extended Wing Technique Approach for the Detection of Winding Interturn Faults in Three-phase Transformers Makarand Sudhakar Ballal†, Hiralal Murlidhar Suryawanshi*, and Bhupesh Nemichand Choudhari** †*Department of Electrical Engineering, Visvesvaraya National Institute of Technology, Nagpur, India **Department of Electrical Engineering, P. E. S. College of Engineering, Aurangabad, India
This paper presents a novel approach to diagnose interturn insulation faults in three-phase transformers that operate at different loading conditions. This approach is based on the loci of instantaneous symmetrical components and requires the measurement of three input primary winding currents and voltages to diagnose faults in the transformer. The effect of unbalance supply conditions, load variations, constructional imbalance, and measurement errors when this methodology is used is also investigated. Wing size or length determines the loading on the transformer. Wing travel and area determine the degree of severity of fault. Experimental results are presented for a 400/200 V, 7.5 kVA transformer to validate this method.
LINK
http://manuscript.jpe.or.kr/ltkPSWeb/pub/pubfpfile.aspx?ppseq=973
Assinar:
Postagens (Atom)