Winds of Change: Full Documentary

Encuentro con la Ciencia con Modesto Montoya 06-02-11

Design Tools for Power Electronics: Trends and Innovations

Uwe DROFENIK*, Didier COTTET**, Andreas MÜSING* and Johann W. KOLAR*
* Power Electronic Systems Laboratory, ETH Zurich, ETH-Zentrum / ETL H13, CH-8092 Zurich, Switzerland
Phone: +41-1-632-4267, Fax: +41-1-632-1212, E-mail: drofenik@lem.ee.ethz.ch
** ABB Switzerland Ltd, Corporate Research, CH-5405 Baden-Dättwil, Switzerland
Abstract: Numerical simulation is a standard procedure in
the design of power electronic systems. With simulation, one
can test new concepts immediately without the need to order
components and assembling which might be time-consuming
and expensive. If something fails, there is no destruction but
information about too high voltages and/or currents. Critical
operating states just before failure can be exactly
reproduced, and currents, voltages and junction
temperatures can be easily monitored in simulation which
makes it comparably easy to identify problematic designs.
Expensive equipment for measurement, power supply and
load which is essential for testing prototypes is not needed in
a first design stage. Further advantages of simulation are the
ability to easily visualize fields, flows and distributions of
physical properties, and the ability of automated parameter
optimization and/or statistical analysis with Monte Carlo
techniques.
Due to these advantages it would be desirable to replace
designing and testing prototypes by numerical simulations as
far as possible in order to reduce development time, save
development cost and detect reliability problems.
Unfortunately, practical simulation will never fully map reality.
The power electronic system under investigation has to be
simplified in order to be able to handle the model with a
computer. Numerical simulation will always give a result, but
it is up to experience and knowledge of the design engineer
to verify the usefulness and/or accuracy of the result.
In the paper we discuss what can be numerically simulated,
what limits are given to modelling by scaling laws and what
kind of developments we might experience in the future.
Emphasis is on the numerical simulation of converter
systems.
FUL TEXT HERE:
http://www.pes.ee.ethz.ch/uploads/tx_ethpublications/4347884.pdf

Design and Implementation of Paralleled Multi-Inverter Systems with Redundancy and Hot-swap Features

Design and Implementation of Paralleled Multi-Inverter Systems with Redundancy and Hot-swap Features author (eng)：JIA-Wei He INSTITUTE OF ELECTRICAL ENGINEERING COLLEGE OF ENGINEERING NATIONAL CHUNG CHENG UNIVERSITY -2004
This thesis proposes redundancy and hot-swap features for paralleled multi-inverter systems with voltage control and current weighted distribution control (CWDC) strategy. With a CWDC strategy, instantaneous current is fed back and monitored; thus, weighted output current distribution and fast regulation among the inverters can be achieved for linear and nonlinear loads. Additionally, the proposed paralleled system is equipped with the features of redundancy and hot-swap; therefore, system power rating can be expanded readily and it has high maintainability. Simulation results and hardware measurements from a two-inverter system with either equal or different power ratings have demonstrated the feasibility of the proposed control scheme in fast regulation and weighted current distribution. The proposed redundancy and hot-swap features have improved reliability and stability of the paralleled multi-inverter system.
MAIORES INFORMAÇOES:http://ndltd.ncl.edu.tw/cgi-bin/gs32/gsweb.cgi/login?o=dwebmge

http://ndltd.ncl.edu.tw/cgi-bin/gs32/gsweb.cgi/ccd=F84qJ_/webmge?switchlang=en

Carga eletronica regenerativa para testes de fontes de energia eletrica utilizando conversor com capacitor flutuante

AUTOR(ES)
Edson Adriano Vendrusculo
RESUMO
The conventional method for testing power supplies, batteries, uninterruptible power supply (UPS) and other sources of electric power uses resistors as load. This results in wasted heat and increases the equipments production cost.This work presents a Regenerative Electronic Load to substitute those resistors. The basic topology is a capacitive idling Cuk converter. This converter allows to control independently the input current and permits to provide a sinusoidal output current. An appropriate-gate command allows to have some soft-commutation without the use of any auxiliarycircuit. The same converter, with input and output changed, can operate as a Power Supply with Input Power Factor Correction. The characteristics of soft-commutation and high efficiencyare maintained. A simplehigh-efficiencytransformer allows output isolation. AlItheoretical results are experimentally verified
No setor elétrico algumas indústrias que produzem fontes de alimentação, "no-break" e estabilizadores de tensão testam estes equipamentos, utilizando resistores para simulação da carga. Isto acarreta perda de energia elétrica por geração de calor. O resultado é o aumento do custo de produção. Este trabalho apresenta uma Carga Eletrônica Regenerativa que substitui os resistores. A energia drenada do equipamento sob teste é devolvida à rede, e o gasto de energia limita-se às perdas nos componentes da carga eletrônica. A topologia básica é um conversor Cuk com capacitor flutuante. Este conversor permite controlar independentemente as correntes de entrada e saída. A topologia apresenta comutações suaves, do tipo (ZVS), sem a necessidade de circuitos adicionais. O mesmo conversor , mas com as posições de entrada e saída invertidas, pode ser utilizado como Fonte de Tensão Com Alto Fator de Potência. As características de comutação suave e alto rendimento são preservadas. O conversor permite obter isolação em alta frequência. Protótipos, em ambas configurações, comprovam os resultados teóricos .

LINK PARA O TEXTO COMPLETO:http://cutter.unicamp.br/document/?code=vtls000106877