AUTOR DO BLOG ENG.ARMANDO CAVERO MIRANDA SÃO PAULO BRASIL
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“GRAÇAS A DEUS PELA VIDA,PELA MINHA FAMÍLIA,PELO TRABALHO.PELO PÃO DE CADA DIA,POR NOS PROTEGER 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”
https://picasion.com/
domingo, 8 de fevereiro de 2015
Avoiding Pitfalls in Coordination of Multi-Mode UPS and STS L Giuntini
Session F1.04 - Avoiding pitfalls in coordination of multi-mode UPS and STS L Giuntini From: PEMD 2014, Session F1: Energy Conversion and Storage, 8 - 10 April 2014, Manchester 08 April 2014 Power channel
1.Introduction
Uninterruptible Power Supplies (UPS) provide power conditioning and backup for mission critical applications, the typical example being the protection of Information Technology (IT) equipment in data centres installations. In this context, double-conversion is the preferred UPS topology [1], following the superior protection offered by the AC-DCAC conversion. However, the multiple conversion steps limit the efficiency of such topology. Therefore, some doubleconversion UPS have evolved towards Multi-mode operation, where efficiency is maximized by selecting the operating mode depending on the environmental conditions (namely, the power quality of the input mains). Performance of Multimode UPS and compatibility with the typical load requirements have been extensively discussed in [2, 3, 4]. At the same time, applications requiring the highest level of availability may improve their distribution reliability by means of redundancy. Particularly, multiple sources may be tied together by means of Static Transfer Switches (STS). These devices may switch between separate sources whenever the voltage of the active source is sensed as going out of given tolerances, just as in Multi-mode UPS. Therefore, the application of Multi-mode UPS operation and STS protection in the same installation poses significant challenges. This paper addresses the coordination of Multimode UPS and downstream STS by highlighting common pitfalls to be avoided,
2 Multi-mode UPS
Figure 1 depicts a basic block diagram for a doubleconversion
transformer-based UPS
LINK VIDEO
http://scpro.streamuk.com/uk/player/Default.aspx?wid=19227&ptid=1066&t=0
sábado, 7 de fevereiro de 2015
sexta-feira, 6 de fevereiro de 2015
Modelagem da Dinâmica de Sistemas e Estudo da Resposta
Modelagem da Dinâmica de Sistemas e Estudo da Resposta - Segunda Edição Esta obra atende a cursos de graduação e cursos iniciais de pós-graduação cujos respectivos programas contemplem modelagem da Dinâmica de Sistemas. A técnica de modelagem aqui ensinada utiliza metodologia especial que se resume na divisão das expressões matemáticas em dois grupos: equações e relações. Foi acrescentado ainda o estudo da resposta, assunto indispensável para compreender o comportamento dinâmico de sistemas, necessário na elaboração de projetos, análise e avaliação de sistemas. Os assuntos foram cuidadosamente selecionados e didaticamente desenvolvidos, com base na experiência de muitos anos de ensino de modelagem.
LINK ORIGINAL
http://issuu.com/rimaeditora/docs/modelagem_segedicao_parte_1/1
COMSOL WEBINAR Title: Tech Insider: Transformer and Inductor Modeling with COMSOL Multiphysics February 12, 2015 Time: 02:00 PM Eastern Standard Time
Summary
Thursday, February 12, 2015 • 2:00 PM Eastern Standard Time
To minimize transmission losses, electrical grids transport power over distances at low currents and high voltages. Improving the performance and reliability of transformers, which are vital to minimizing these losses, has great potential value. Multiphysics simulation enables accurate transformer and inductor design by accounting for coupled electrical and thermal effects, such as Joule heating. This webinar will introduce techniques for modeling inductive couplings and will demonstrate the simulation of a transformer in COMSOL Multiphysics. The presentation will also include a Q&A session.
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LINK
segunda-feira, 2 de fevereiro de 2015
domingo, 1 de fevereiro de 2015
sexta-feira, 30 de janeiro de 2015
terça-feira, 27 de janeiro de 2015
SISTEMA AUTOMÁTICO PARA REGULAÇÃO DE TENSÃO EM REDES DE BAIXA TENSÃO Por: Jean C. da Cunha Orientador: Marcello Mezaroba Dr.-UDESC-UNIVERSIDADE DO ESTADO DE SANTA CATARINA-BRASIL
FILTRO HARMONICOS PASSIVO - Cassiano Rech – Doutor (UFSM)-UDESC
FILTRO HARMONICOS PASSIVO - Cassiano Rech – Doutor (UFSM)-UDESC
LINK
http://www.joinville.udesc.br/portal/professores/mezaroba/materiais/CEN____Aula_6___Filtros_de_harm_nicas_passivos.pdf
EXERCICIOS RESOLVIDOS EPO-1 ELETRÔNICA DE POTÊNCIA I -PROVA 2 -UDESC- DR. ENG LEANDRO MICHELS SANTA CATARINA BRASIL
EXERCICIOS RESOLVIDOS EPO-1 ELETRÔNICA DE POTÊNCIA I -PROVA 2 -UDESC- DR. ENG LEANDRO MICHELS SANTA CATARINA BRASIL
LINK
https://copy.com/9sY2FB9sCSBQgZwN
EXERCICIOS RESOLVIDOS EPO-1 ELETRÔNICA DE POTÊNCIA I -PROVA 1 -UDESC-DR. ENG LEANDRO MICHELS
EXERCICIOS RESOLVIDOS EPO-1 ELETRÔNICA DE POTÊNCIA I -PROVA 1 -UDESC-DR. ENG LEANDRO MICHELS
LINK ORIGINAL
http://www.joinville.udesc.br/portal/professores/michels/materiais/Exerc_cios_resolvidos___EPO_I___Prova_1.pdf
LINK DIRECTO
https://copy.com/SPAUIjdHr9Oic38j
CURSO ELETRÔNICA DE POTÊNCIA I - PROF. LEANDRO MICHELS DR. ENG. CURSO DE ENGENHARIA ELÉTRICA DEPARTAMENTO DE ENGENHARIA ELÉTRICA UNIVERSIDADE DO ESTADO DE SANTA CATARINA-BRASIL
LINK DO CURSO DE ELETRÔNICA DE POTÊNCIA I
https://copy.com/N903ZBoORVEx1oOS
EXCELENTE CURSO DE ELETRONICA DE POTENCIA I MINISTRADO POR MEU DISTINGUIDO AMIGO E COLEGA DR. ENG. LEANDRO MICHELS DO DEPARTAMENTO DE ENGENHARIA ELETRICA UDESC SANTA CATARINA BRASIL
domingo, 25 de janeiro de 2015
dq-based individual phase control of three-phase four-wire PWM rectifier for UPS Kim,SeungHo Dept. of Electrical Engineering Graduate School of Industry and Engineering Seoul National University of Science and Technology
dq-based individual phase control of three-phase four-wire PWM rectifier for UPS Kim,Seung Ho Dept. of Electrical Engineering Graduate School of Industry and Engineering Seoul National University of Science and Technology ABSTRACT Recently, the power quality sensitive loads such as computer and communications are so increased that the power supply with good power quality has come to the fore. However, it is possible that the public grid is interrupted by unexpected fault. Therefore, the UPS(uninterruptible power supply) has become an alternative solution to solve this problem. Generally, the UPS consist of a rectifier, a battery, and a PWM inverter and recently they use IGBT PWM rectifier to reduce input THDi and improve the input power factor. In this configurations the three-phase four-wire input UPS is widely used to eliminate the transformers in the UPS system. The aims of control algorithm for the IGBT PWM rectifier in three-phase four-wire UPS is a unity power factor. The SVM(space vector modulation) is one of the most popular and preferable PWM scheme because it reduces the commutation losses and harmonics in the output voltage, and has higher modulation index than SPWM(sinusoidal PWM) but they need a 3D SVM to control three-phase four-wire PWM rectifier and have some difficulties like as selection of inductance of input inductor and controls the neutral current. To improve this problem the another control algorithm which controls each phase individually has been suggested but this control algorithm use analog based control so ir's so sensitive and unstable. So another new algorithm which is added d-q control to control algorithm which controls each phase individually is suggested and it can control stably and can reduce neutral current too. This can be seen by computer simulation and experimental result.
sábado, 24 de janeiro de 2015
Power Quality Improvement of Single-Phase Grid-Connected Photovoltaic Inverter - Trung-Kien Vu- Department of Information and Communications Engineering, Graduate School of Chungnam National University
A Dissertation for the Degree of Doctor of Philosophy
Power Quality Improvement of Single-Phase
Grid-Connected Photovoltaic Inverter
Department of Information and Communications Engineering
Graduate School
Chungnam National University
By
Trung-Kien
ABTRACT
The economical and environmental impacts of fossil fuels have forced society to investigate sustainable solutions. The interest has focused on the renewable energy sources since the green and clean benefits. Consequently, investments in research and development in the field of power electronics have increased proportionally, especially in high voltage and high power grid-connected systems. The distributed power generation (DG) systems are becoming more common as the need for electric power increases because of taking advantage of using different energy sources such as wind and solar. A few examples are hybrid cars, solar houses or hospitals in remote areas where providing clean, efficient and reliable electric power is critical to the loads. In such systems, the power is distributed from the source side to the load side via power electronic converters in the system. At low and medium power applications, the task is often left to single-phase inverters where they are the only interface between sources connected to dc bus and loads connected to an ac bus. This dissertation investigates the power quality improvements to properly regulate the power flow between renewable source and the utility network. The control method for single-phase inverters used in low and medium power DG systems is based on (and also takes the advantage of) the well-known d-q transformation (which is mostly employed for three-phase converters’ analysis and control design). The transformation requires at least two independent phases for each state variable in the system; thus a second phase must be created. This virtual-phase can be done by DSP implementation, hence there is no need for additional hardware in the system, making it more attractive and cost effective method. The Proportional-Resonant (PR) controller based current control scheme, compared with conventional Proportional-Integral (PI) controller, not only provides a superior transient response but also provides a zero steady-state error as well as a high disturbance rejection and a low output current THD under grid-tie mode operation. The entire controller can be implemented in a DSP digital control board which is becoming more common in power electronics converters within the past decade. Special attention is given to systems which demand a third-order LCL-filter as interface between inverter and grid. This filter configuration is widely employed in high power systems, in which the switching frequency is typically limited by the switching devices. The LCL-filter has the ability to reduce the level of harmonic distortion with less inductance, compared with the first-order L filter. On the other hand, it introduces undesirable characteristics, such as resonance, that must be compensated by the controller. Another issues related to the switching devices such as IGBT, MOSFET and others have very high switching frequency above tens of kilohertz. A blank-time is needed to avoid the conduction overlap of two switching devices in the same leg. This blank-time causes the phase error, output voltage distortions and fundamental voltage drop, which degrade the control performance and hence, may cause the power loss during generation process. Comparative analysis and design procedures of conventional PI and PR controller for current control technique have been presented. Furthermore, an output low-pass LCL-filter design procedure and a dead-time compensation method for a 3kW single-phase grid-connected full-bridge PV VSI have also been introduced in this study with the final results are implemented in a DSP TMS320F2812 based digital controller board.
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