Archimedes III Session I
Chair: C. Alafodimos- P. Papageorgas - M. Rangousi
B.1.1. Inverters, Micro-Inverters for photovoltaic systems (Modeling, Design,
System, Development, Control Techniques)
C. Alafodimos
Abstract
The photovoltaic technology in now days is expanding rapidly. Several researches are
focused on upgrading and increasing the overall efficiency. In the last years, many
topologies of solar inverters have been proposed for increasing the efficiency [1,2,11].
The TEI team has been in this field of research for the last three and a half years.
Our research interest is to work in the field of inverters and micro-inverters, trying to
reduce the size and increase the efficiency. We are going to deal with power
management issues such as power load, power storage, efficient operating techniques,
identification of maximum operating point, interface and synchronization with the
public electrical grid. We are also going to construct model panels, combine
photovoltaic devices along with Cherenkov detectors and study telematic system for
monitoring, data collection and control of the inverter from distance.
There are five workpackages. In the first WP we are going to study and model the
sources-consumption. In the second, study of three-phase inverter and laboratory
development for high-power and performance systems. In the third, we will design,
simulate and develop a prototype micro-inverter. In the fourth, a stand-alone pv power
generation system for cosmic ray detectors, will be designed. In the last W.P. we are
going to deal with issues such as techniques on inverters’ control, fault protection
techniques and power management.
After the successful completion of the study the expected results are:
More efficient models for solar systems simulation.
A high power inverter system which can provide the experience of the systems that
are in the market.
A micro-inverter which combines low cost with high efficiency and reliability.
The study and implementation of a PV system for cosmic ray experiments, may give
more efficient and cost effective solutions. New control methods for both microinverters and high power inverters.
B.1.2. RF-Powered smart wireless sensor system
E. Kyriakis - Bitzaros
Abstract
Radio Frequency Identification (RFID) is an electronic tagging technology that allows
automatic objects identification at a distance, using an electromagnetic based requestand-response exchange of a predefined codeword stored in a tag. By attaching Radio
Frequency (RF) tags to objects, RFID technologies enable various applications such
as supply chain management, transportation payment, warehouse operations, library
management and so on. Recently, new types of RFID based applications such as
activity monitoring and localization have been proposed. On the other hand, in many
cases there is the need to collect and submit varying environmental or other data, like
temperature, humidity, strain, or even heart rate, blood pressure etc. Wireless Sensor
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Networks (WSNs) is an enabling technology based on the 802.15.4 LR-WPAN IEEE
Standard and the later evolved ZigBee alliance, which allows the development of
previously unseen services ranging from defense, security and civil protection to
personal health systems, smart home automation, the smart dust and the internet of
things and so forth.
The proposed work aims at giving the guidelines to bridge the gap between the
battery-less operation of RFID tags and the extended service applications offered by
WSNs and to develop an RFID and sensory system operating at 2.4GHz ISM band,
under given output power, physical, MAC, network and application layer constraints
such as the ones imposed by ZigBee. The concept of RFID networks has been
described in the literature but, to the best of our knowledge, not yet implemented. In
order to highlight the lack of current RFID applications at the 2.4GHz ISM band, it is
worth noting that there have been reported a few works but actually not implementing
a complete sensor tag but some of the required submodules. The main innovative
features of the proposed system are the use of the 2.4GHz frequency band for RFID
systems, the low reader EIRP, the low rectifier sensitivity, the high tag antenna gain
and the preservation of compatibility with ZigBee networks. Following that, certain
other advantages that will come up include the minimization of interference to
adjacent circuits, due to extremely low requirements in RF power, the reduction of the
antenna size and the minimization of energy consumption of the self powered sensor
node.
B.1.3.Open source platform for wireless sensor network.Review of commercial
solutions suitable for education.
P. Papageorgas
Abstract
During the last decade, the rapid evolution in the fields of wireless communications
and computing, enabled the development of systems on chip with embedded
microcontrollers, wireless modems and sophisticated power management capabilities.
The envisagement of “smart dust” and “internet of things” can be realized today with
the introduction of advanced CMOS system on-chip wireless nodes, building “ad hoc”
Wireless Sensor Networks (WSNs). In this article a review of the commercial
available platforms for wireless sensor networks will be presented focusing in the
open source available realizations that are also suitable for higher education in the
associated scientific fields.
Keywords: Wireless sensors networks, embedded networkong, smart objects, Internet
of things,.
B.1.4. A distributed microelectronic system for environmental monitoring with
emphasis on sound mapping
M. Rangoussi
Abstract
The design and development of a distributed microelectronic system for acoustic monitoring
of areas of environmental interest is described in this paper. It is based on a wireless acoustic
sensors network that supports field recording of sound/acoustic signals, main processing
through a hierarchical pattern recognition scheme and the use of the results to feed a software
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application developed for the automated generation of sound maps. The proposed sound maps
extend the notion of noise maps to cover an environmental acoustic content wider than noise.
They are periodically updated on the basis of real-field measurements communicated to the
software application. They provide accuracy, integrity and timeliness of environmental
information; therefore, they constitute valuable tools for the monitoring of environmentally
sensitive areas as to the impact of anthropogenic activities as well as to the evolution of
natural factors (fauna-climate) that can readily support decision making for protection
measures. The task includes:
•Development of innovative methods and software applications for (i) hierarchical
recognition / classification of sound/acoustic events and sources and (ii) automated generation
of sound maps.
•Field measurements of sound/acoustic environmental events.
•Distributed microelectronic system: hardware design and development of a small-scale
wireless sensor network.
•Integration of the two software applications with the hardware system and wireless sensor
network, System integration and scaling study, Case study.
Keywords: microelectronic system, sound maps, environmental monitoring, wireless sensor
network.
B.1.5. Investigation of the possibility of energy saving in existing DC motor
driving systems in the Hellenic territory and the quality of electric power in
these systems
G. Ch. Ioannidis
The proposed research work is to explore the possibility of saving energy in existing
DC drive systems in Greece (eg ISAP, METRO, textile & paper industries) and the
power quality in these systems.
The purpose of this research is to develop new motor drive system(s) and control
technique(s) to upgrade existing DC drive systems in order to save power and
effectively control the speed and torque of these systems limiting the oscillations
presented on the axis of the motors and therefore the mechanical stress on them.
We will also study the problems arising from the injection of harmonics in the electric
network, coming from the produced DC voltage (due to rectification) and the
operation of power circuits (DC drives).
The project will begin with extensive literature research of relevant work (papers) and
books. Furthermore, power measurements on applied DC drive systems and harmonic
measurements will be conducted. In addition, the new high-voltage low loss
semiconductor switches relying on silicon carbide (SiC) will be studied, and
compared to the existing silicon (Si) semiconductor switches.
Also, the possibility of applying the H∞ theory to optimize the control of DC drive
systems and the design/simulation of reduced losses circuits/converters for DC motor
systems will be considered.
All the above will be applied to a small-scale pilot scheme from which power and
harmonic measurements will be conducted. During this, research graduate thesis will
be written and the original work will be the announced / published in conferences /
journals.
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B.1.6. A comparative evaluation of Hydrogen-Based technologies and other
energy storage systems for the support of autonomous RES-Based power
stations
J. Kaldellis
Abstract:
The European Union (EU) has long since adopted policy strategies for the promotion
of renewable energy sources (RES), with the most recent targets (Directive
2009/28/EC) committing EU members to achieve a challenging 20% of gross energy
consumption covered by RES by the year 2020. In this context, Greece must adhere to
the respective national RES targets, dictating that by 2020 contribution of RES should
correspond to 40% of the national gross electricity consumption, although it must be
noted that up to now RES participation has been rather limited, not exceeding 12%.
As a result, ambitious targets set by the Greek State may be accomplished only in the
case that large-scale penetration of RES is encountered in the Greek territory during
the following years. For this to happen however, exploitation of regions determined
by high quality RES characteristics (e.g. the Aegean Sea region) must be supported.
In this context, of special interest is the consideration of autonomous/distributed
energy systems (i.e. island electrical grids), where large-scale penetration of RES
encounters certain constraints. To eliminate inherent characteristics of RES power
generation and allow for its increased exploitation, application of hybrid RES-based
installations with the use of energy storage systems (ESSs) comprises a promising
solution that allows for investigation of several different energy storage technologies.
Considering the above, the specific research aims to provide a profound evaluation of
different ESSs for the support of hybrid RES-based configurations in autonomous
electrical networks, with emphasis given on the promising hydrogen technologies,
while based on both an experimental and an analytical simulation approach,
designation of optimum operation directions for such configurations is the primary
goal of the specific research work.
Keywords:Renewable Energy Sources, Energy Storage, Island Networks, Hydrogen,
Fuel cells
B.1.7. Health care system in Greece and OECD: Evolution and perspectives
Th. Papailias
Abstract
The object of the proposed work is the recording of development of Health Systems
in Greece and in countries of OECD -after the Second World War- and concretely the
measurement of their effectiveness as well as the questions that emerge in order to
proceed to their revision.
The expected results will derive from the investigation of the defining factors of
development regarding the Health Systems in Greece and in the countries of OECD as
well as their comparative analysis.
In order to achieve our object, initially, we will present the data that concern the
expenditure (public and private), the material and human resources and health
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indicators in general. At the same time, there will be a review of the relative
bibliography regarding the problems of Health Systems and Social Insurance. We will
also present the way of economic and accountant data monitoring in general level, as
well as in case studies regarding the operational cost of the Greek National Health
System.
According to the above matters, we will interpret the Greek citizen’s low degree of
satisfaction from the Health System in relevance with the European standards, and we
will propose solutions in order to improve its efficiency.
The research is consisted of seven (7) work packages.
Keywords:Health system , OECD , social insurance , private insurance , satisfaction ,
effectiveness , health sector , health indicators
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