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”

sábado, 30 de setembro de 2017

Introduccion Al Analisis De Circuitos Edicion 10 Robert L. Boylestad


NAVEGANDO HOY EN LA INTERNET ENCONTRE ESTE EXCELENTE LIBRO ESTUDIE CON EL CUANDO ESTUDIE INGENIERIA ELECTRONICA EN LA GLORIOSA UNIVERSIDAD NACIONAL MAYOR DE SAN MARCOS LINMA PERU,ES DE ACCESO LIBRE ESTA EN EL SITE ARCHIVE.ORG UN PROYECTO UNIVERSAL DE DIFUSION DEL CONOCIMIENTO.

 Introduccion Al Analisis De Circuitos Edicion 10 Robert L. Boylestad by Robert L. Boylestad
 Topics
Introduccion, Analisis, Circuitos, Edicion, 10, Robert, Boylestad Collection opensource Language Spanish Ésta es la edición actualizada del texto Introducción al análisis de circuitos, que durante más de tres décadas ha sido el clásico en este campo. Desarrolla la presentación más completa de la materia e incluye ejemplos que ilustran paso a paso los procesos y los fundamentos del campo con una base sólida y accesible. Es uno de los libros mas usados y recomendados para empezar en el mundo de la electrónica. Conceptos claros y profundamente explicados para lograr el mejor entendimiento y asimilación de los fenómenos.
LINK ORIGINAL EN LA WEB:
https://archive.org/details/IntroduccionAlAnalisisDeCircuitosEdicion10RobertL.Boylestad
LINK DIRECTO DEL LIBRO
https://archive.org/download/IntroduccionAlAnalisisDeCircuitosEdicion10RobertL.Boylestad/Introduccion%20al%20analisis%20de%20circuitos%20-%20Edicion%2010%20-%20Robert%20L.%20Boylestad.pdf

domingo, 24 de setembro de 2017

Transformer comparison by core form and winding structure Woong-Jae Kang Department of Electrical Engineering Graduate School Gyeongsang National University




Flyback Transformer Performance by Core and Winding Structure 

 Abstract 
Transformer comparison by core form and winding structure Woong-Jae Kang Department of Electrical Engineering Graduate School Gyeongsang NationalUniversity 

Supervised by Professor Hwi-Beom Shin
The leakage inductance of the flyback transformer causes the voltage spike in the MOSFET switch. The RCD snubber is typically used to reduce the voltage spike. The current method change the transformer winding structure to reduce effect of leakage inductance, because it is difficult to reduce influence of leakage inductance any more in circuit improvement. In this paper, it show the change for voltage spike and ringing depending on winding structure and core form of transformer.
LINK
http://www.mediafire.com/file/6kj45ksizg7z5m2/FLYBACK_PLANO.pdf

terça-feira, 5 de setembro de 2017

Development of Photovoltaic Inverter used Grid-Connected Distributed Power Jeong-Do Kim Department of Electrical Engineering Graduate School Pukyong National University









Development of Photovoltaic Inverter used Grid-Connected Distributed Power 
Jeong-Do Kim 

Department of Electrical Engineering Graduate School Pukyong National University 

Abstract

This paper relates to grid-connected single-phase inverter system, the proposed system is a gate pulse signal was added to the active auxiliary resonant circuit in the bridge arm of a conventional grid-connected single-phase half-bridge inverter, main switch is modulated by the SPWM method by configuring so that the, take a feature that can control the multi-phase alternating current can be used in the batch phase inverter. And active by the secondary resonance also work during the snubber circuit a dead time period, soft switching is possible because it actually turns a basic switch in the on state-off and resonant operation after turning the other main switch-which was applied to the whole of the gate signal have the characteristic. Further, when the conventional program is shorter than the width of the gate pulse signal active auxiliary resonant snubber operation time in the operation in the hard switching to occur even if the H, L is the reverse of the gate pulse signal. This power supply is in reversal of the power supply circuit is a short circuit may possibly be damaged since. To prevent this, this paper has set the ARCP operation time and modulation rate settings and processes the pulse of the gate pulse signal reversal was the program not to occur. 114 Further, as the main switch is in the off state to the time when the other switch is turned on, and the dead time is a hard switching method in case of the conventional method to sequence the switching pattern 1.5[μs], While for setting the dead time of the soft switching system with 2.0[ms], For this paper the sequence switching patterns applied to the soft-switching method is 4.0[μs] because the pulse width of the hard-switched at the same modulation rate and time to get a high density to suppress the resonant inductor current as a whole small effect of improving the efficiency have. Running a soft switching operation by the switching pattern sequence scheme applied to the paper, it is possible to suppress the surge voltage and the surge current, the generation of noise of the device is reduced as compared to the effect of the hard switching method.

LINK:
http://www.mediafire.com/file/1dyn6jy9g5767gj/PHOTOVOLTAIC_INVERTER.pdf

quinta-feira, 31 de agosto de 2017

A High Efficiency Two-stage Inverter for Photovoltaic Grid-connected Generation Systems Jiang Liu,Shanmei Cheng ,and Anwen Shen - Huazhong University of Science and Technology, Wuhan, China






Fig. 3. Conventional BHB inverter and proposed two-stage inverter ( (a) conventional BHB topology, (b) proposed two-stage topology, (c) conventional asynchronous PWM modulation method, (d) proposed time-sharing synchronous PWM modulation method, (e) conventional separate dual loop controller, (f) proposed hybrid current controller).

A High Efficiency Two-stage Inverter for Photovoltaic Grid-connected Generation Systems Jiang Liu,Shanmei Cheng ,and Anwen Shen Huazhong University of Science and Technology, Wuhan, China 

Abstract 

Conventional boost-full-bridge and boost-hybrid-bridge two-stage inverters are widely applied in order to adapt to the wide dc input voltage range of photovoltaic arrays. However, the efficiency of the conventional topology is not fully optimized because additional switching losses are generated in the voltage conversion so that the input voltage rises and then falls. Moreover, the electrolytic capacitors in a dc-link lead to a larger volume combined with increases in both weight and cost. This paper proposes a higher efficiency inverter with time-sharing synchronous modulation. The energy transmission paths, wheeling branches and switching losses for the high-frequency switches are optimized so that the overall efficiency is greatly improved. In this paper, a contrastive analysis of the component losses for the conventional and proposed inverter topologies is carried out in MATLAB. Finally, the high-efficiency under different switching frequencies and different input voltages is verified by a 3 kW prototype.

Keywords: Overall efficiency, Photovoltaic array, Time-sharing synchronous modulation, Two-stage inverter

LINK FULL TEXT: http://jpe.or.kr/archives/view_articles.asp?seq=1351

terça-feira, 29 de agosto de 2017

Elimination of the Inrush Current Phenomenon Associated with Single-Phase Offline UPS Systems Syed Sabir Hussain Bukhari, Shahid Atiq and Byung-il Kwon * Department of Electronic Systems Engineering, Hanyang University ERICA, South Korea


Elimination of the Inrush Current Phenomenon Associated with Single-Phase Offline UPS Systems Syed Sabir Hussain Bukhari, Shahid Atiq and Byung-il Kwon * Department of Electronic Systems Engineering, Hanyang University ERICA, Ansan 426-791, Korea 

 Abstract: Critical load applications always rely on UPS systems to uphold continuous power during abnormal grid conditions. In case of any power disruption, an offline UPS system starts powering the load to avoid blackout. However, this process can root the momentous inrush current for the transformer installed before the load. The consequences of inrush current can be the reduction of output voltage and tripping of protective devices of the UPS system. Furthermore, it can also damage the sensitive load and decrease the transformer’s lifetime. To prevent the inrush current, and to avoid its disruptive effects, this research suggests an offline UPS system based on a current regulated inverter that eliminates the inrush current while powering the transformer coupled loads. A detailed comparative analysis of the conventional and proposed topologies is presented and the experiment was performed by using a small prototype to validate the performance, and operation of the proposed topology. Keywords: uninterruptible power supply; offline; inrush currents; current regulation

VIEW FULL TEXT :
https://pdfs.semanticscholar.org/0374/8dcd3f5ed69daf4128b971797417dcb92cde.pdf