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

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

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

IEEE ESW Brasil 2017 – Electrical Safety Workshop Brasil-WORKSHOP DE SEGURANÇA EM ELETRICIDADE-4 a 5 de outubro de 2017-SALTO SÃO PAULO BRASIL

MUDANDO A CULTURA DE SEGURANÇA ELÉTRICA 

WORKSHOP DE SEGURANÇA EM ELETRICIDADE 

 O IEEE – Instituto dos Engenheiros Eletricistas e Eletrônicos do Brasil orgulha-se em realizar o IEEE ESW Brasil – Electrical Safety Workshop Brasil, o único seminário totalmente dedicado à segurança em eletricidade. Desde 2003 realizado bi-anualmente, a VIII edição será realizada na cidade de Salto, SP, de 4 a 5 de outubro de 2017, em parceria com a Abracopel – Associação Brasileira de Conscientização para os Perigos da Eletricidade. O seminário é composto de trabalhos técnicos apresentados por profissionais experientes e por especialistas convidados, proporcionando um excelente ambiente com plena participação da plateia. O objetivo do IEEE ESW Brasil é promover a “mudança da cultura da segurança em eletricidade”, visando conscientizar a sociedade de que os serviços de eletricidade devem ser tratados com responsabilidade e seriedade. Trabalhos apresentados no IEEE ESW Brasil já foram publicados no exterior, como o “Explosion risks in underground networks”, de autoria do eng. Estellito Rangel Jr., apresentado no ESW Brasil 2011 e publicado na Revista IEEE Industry Applications Magazine, distribuída em mais de 90 países, no número set/out 2014, pg. 58-63. Para isto, o IEEE ESW Brasil desde sua primeira edição busca incluir na programação não só trabalhos de profissionais destacados no cenário brasileiro, bem como renomados palestrantes estrangeiros especializados em temas como: segurança em eletricidade desde o projeto (Bruce McClung), implantação da gestão de segurança (Lanny Floyd), tratamento de feridos por eletricidade (Mary Capelli-Schellpfeffer), arcos elétricos (Dan Doan) e desenvolvimento de soluções para painéis elétricos resistentes a arcos (Marcelo Valdes). Estas características consolidam o IEEE ESW Brasil como um seminário internacional de alto nível.

LINK ORIGINAL
http://www.ieee.org.br/eswbrasil/

EQUIPE DO PERU CAMPEÃO DA XXVIII OLIMPÍADA DE MATEMÁTICAS CONE SUL -EQUADOR-AGOSTO 2017

BRILHANTE ATUAÇÃO DO EQUIPE DO PERU NA OLIMPÍADA DE MATEMÁTICA CONE SUL NO EQUADOR ,PRIMEIRO LUGAR COM 04 MEDALHAS: 02 MEDALHAS DE OURO E 02 MEDALHAS DE PRATA

Daniel Benavides (medalla de oro-puntaje perfecto)
Diego Lázaro (medalla de oro)
Renzo Balcazar (medalla de plata)
Joseph Altamirano (medalla de plata)

COLABORAÇÃO DE MEU COLEGA PERUANO PROFESSOR JORGE TIPE