UNIDADE DE OSMOSE REVERSA ACIONADA POR ENERGIA SOLAR

UNIDADE DE OSMOSE REVERSA ACIONADA POR ENERGIA SOLAR
FOTOVOLTAICA SEM BATERIAS:
Simulação, Projeto e Validação Experimental
FORTALEZA 2005-CEARA-BRASIL
Dissertação submetida à
Universidade Federal do Ceará
como parte dos requisitos para a
obtenção do grau de Mestre em Engenharia Elétrica.
DOUGLAS BRESSAN RIFFEL

ABSTRACT
RIFFEL, D.B.; 2005. Photovoltaic-powered Reverse Osmosis Plant without
Batteries: Simulation, Design and Experimental Validation. Fortaleza. Thesis
(Master degree) – Centro de Tecnologia, Universidade Federal do Ceará.125p.
This research analyzes the combination of photovoltaic generation with
reverse osmosis desalination of brackish water for the supply of dinking water.
Access to potable water and electric power is still an unresolved problem for many
people around the world. The State of Ceará, where this research was carried out,
represents well this reality. A photovoltaic-powered reverse osmosis plant was
installed in laboratory. Through the elimination of the battery, investment costs and
maintenance need could be reduced. At the same time, this changes completely
the operation of the unit, being totally subordinate to the instantaneous conditions
of solar radiation and temperature. A plant design procedure was elaborated that
uses solar radiation statistical data and the seasonal availability of water from
cisterns as design parameters. Two systems were mathematically modeled and
validated by experiment. System 1 uses a motor-pump directly coupled to two 55
Wp photovoltaic modules. System 2 disposes of one additional module and a DCDC
buck converter with maximum power point tracking between the photovoltaic
array and the load. The necessity to regulate the power transferred to the load in
System 2, led to the development of the converter and the tracking algorithm
specially for this application. The simulations allowed the comparison between the
two systems in two conditions: with and without a pressure relief valve coupled to
system 1. Results shown that the System 2 has always a better performance, as a
daily permeate water production, time operation, specific consumption and in the
relationship photovoltaic installed capacity per produced water liter. It was
observed that volumetric pumps, of the diaphragm type in the case, are suitable
for reverse osmosis applications. But, when combined with a photovoltaic array,
maximum power point tracking is necessary. It is important to state that with a
50 % increment in generation capacity a 90% increase in permeate production is
achieved.
Key-words: photovoltaic generation, reverse osmosis, brackish water desalination,
solar energy.

Convertisseurs génériques Applications pour le domaine aéronautique

THESE
présentée pour obtenir le titre de
DOCTEUR DE L’INSTITUT NATIONAL POLYTECHNIQUE DE TOULOUSE
Ecole doctorale : Génie Electrique, Electronique, Télécommunications
Spécialité : Génie Electrique
Par
Jérôme MAVIER

Convertisseurs génériques à tolérance de panne
Applications pour le domaine aéronautique
Abstract
Electric power is of increasing importance in aeronautical systems. As a consequence,
static converters have become widespread, and power electronics is crucial for improving
performance, reliability and competitiveness.
The aim of this thesis is to contribute to the design of electrical networks by using
modular generic converters. To determine their structure, an inventory of power electronics
applications is carried out in the framework of a "more electric" aircraft.
The modularity of these power conversion blocks opens the way for power
segmentation and redundancy, that enables systems availability to increase. Following this
approach, several fault-tolerant inverter topologies are compared, both analytically and by
simulation based on the physical model of a flight surface electrohydrostatic actuator.
For the experimental studies, power electronics modules are designed to operate a
reconfigurable inverter that is dedicated to a permanent magnet synchronous motor drive.
Connected to the neutral point of the wye-connected motor, this inverter has a fourth leg that
acts as a mutualised redundancy.
Lastly, to extend the power electronics generic module’s field of application, three
AC/DC converter topologies are proposed in order to improve power management, in
comparison with conventional topologies, with respect to electrical and thermal design
criteria.

Soutenue le 22 mars 2007 devant le jury composé de :
MM. P. LE MOIGNE Rapporteur
F. MEIBODY-TABAR Rapporteur
F. FOREST Examinateur
L. PRISSE Examinateur
F. RICHARDEAU Encadrant
H. PIQUET Encadrant
P. ROLLIN Invité
Thèse préparée au Laboratoire Plasma et Conversion d’Energie (LAPLACE) – site ENSEEIHT
Unité Mixte de Recherche INPT – UPS – CNRS N°5213

DESIGN METHODOLOGY OF A HIGH POWER DENSITY

SEISMIC MONITOR ONLINE

MONITOR GLOBAL EARTHQUAKES IN NEAR REAL TIME

Design of a 320W Telecoms DC/DC converter.

Introduction
This report describes the design of a 320W Telecoms DC/DC converter. A push-pull forward
converter running with current mode control using the LM5030 from National Semiconductor
delivers high performance and small solution size. Custom planar magnetics from Payton
have been used throughout to reduce component build height, increase efficiency and aid
cooling.
This report contains target specification, schematic, bill of materials, magnetics design
information as well as a detailed design analysis. A full set of performance measurements is
also included taken from the prototype unit shown in Figure 1. Measurements include
conversion efficiency, power stage device temperature rise, line/load regulation, start-up
behaviour, transient load response and loop gain/phase characteristic.

IR Thermography

The design of reliable power electronic converter systems depends
partly on an accurate knowledge of the power stage component
operating temperatures under extremes of load and input voltage.
This article demonstrates how the use of modern infra-red (IR)
imaging techniques can significantly enhance the design qualification
process and show up potential problems at a very early stage in
the product development cycle. The techniques highlighted are
applicable to any power converter system or electronic product
where knowledge of component operating temperatures is
important for reliability modelling and lifetime prediction.
By Dr. Iain Mosely, Technical Director, Converter Technology Ltd

One of the main limiting factors affecting the power capability and
reliability of any electronic power converter system is the operating
temperature of key power stage components. Excessive component
temperature will reduce product operating lifetimes and could result
in early field returns. Traditionally, thermocouples are used to
measure the operating temperature of components.
Whilst thermocouples can give very accurate temperature
measurements, they do have a few potential drawbacks:
• Thermocouples can pick up noise if they are placed near to power
components with high dv/dt switching waveforms present and this
can give misleading measurement results.
• Thermocouples will sink a small amount of heat away from the device
they are attached to. For physically small components, this can lead
to measurement inaccuracy.
• Thermocouples are often only placed on components which are
expected to show a reasonable temperature rise. Other components
may not be monitored at all and this could lead to problems if a
design error leads to a high operating temperature on a component
which hasn’t been monitored.

IR thermography is a non-contact measurement technique which
uses a calibrated infrared camera to form athermal image of the
system under test.
As the measurement technique is noncontact, the noise susceptibility
and heatsinking effects sometimes encounteredwith thermocouples
are no longer an issue. More importantly, an entire PCB can be imaged
which immediately shows up any hotspots or problem components that
may have otherwise been overlooked.

An example thermographic image ofa power converter is shown
in Figure 1.The power converter used has an issue with a snubber
TVS diode which can be seen to be running at >150°. Using the
thermal imaging camera is this example would immediately alert
the designer to a potential problem with the PSU before it reaches
the pre-production or production stage. The real value of thermography
in power electronic design is this ability to rapidly flag potential
design issues at a very early stage.

Infrared Imaging of Power Electronic Converters

Thermal management of electronic devices and packaging is important when dealing with high-voltage high-power systems as excessive device heating can have a catastrophic affect on the performance of a system and can lead to premature device and system failure. Therefore, it is necessary to accurately assess and characterize the thermal performance of power electronic components.
The use of thermal imaging equipment (infrared cameras) allows us to see beyond the visible into the invisible infrared. Our eyes are capable of detecting visible radiation but not infrared radiation. Infrared radiation is a form of electromagnetic radiation as are: visible light, radio waves, ultraviolet, and X-rays. Infrared radiation is longer in wavelength than visible light and is classified in a different waveband. Although few objects emit in the visible waveband, in the infrared waveband all objects emit. It is only that it cannot be seen with the physical eye. An infrared camera, therefore, becomes the "infrared eyes" into the infrared world. Infrared radiation is absorbed and emitted by objects. Absorptivity is the measure of how well an object or material absorbs radiation. Emissivity is the factor that correlates to the ability of an object to radiate infrared energy. In the way that visible light reflects off a mirror, infrared radiation reflects off many objects. For example, infrared radiation reflects clearly off metals such as aluminum. The fact that metals are good reflectors makes them poor emitters.

Manufacturing and process engineers boost efficiency and cut costs by turning to machine-vision systems like automated infrared (IR) imaging. The technique is being used in a host of industrial production applications, including process monitoring and control, quality assurance, asset management, and machine-condition monitoring.

Simulation, Design and Construction of High Voltage DC Power Supply at15 kV Output Using Voltage Multiplier Circuits

Simulation, Design and Construction of High Voltage DC Power Supply at
15 kV Output Using Voltage Multiplier Circuits
N. Mariun, D. Ismail, K. Anayet, N. Khan and M. Amran
School of Electrical System Engineering, Northern Malaysia University College of Engineering
01000 Kangar, Perlis, Malaysia.
Abstract: This study describes the details of high voltage DC power supply whose output voltage is 15
kV. In this study, we review the major aspects of the design of voltage multiplier circuits and
constructed a prototype power supply based on simulation, design and implementation of the hardware
works in the laboratory. Its simulation works done by using EMTDC PSCAD and PSPICE software.
Experimental results are presented to verify the simulation results.

INTERNATIONAL JOURNAL OF PLASMA SCIENCE AND ENGINEERING

About this Journal
International Journal of Plasma Science and Engineering is a peer-reviewed, open access journal that publishes original research articles as well as review articles in all areas of plasma science and engineering.

Physics of Free Energy Device

Physics of Free Energy Device
There is no energy crisis in the world. Instead, there is amnesia in the minds of the scientists and the physicists.