Bashir, {Safia Babikir}, {Hasan A. } Zidan, and Stanimir Valtchev. "
An Improved Voltage Ripple Control Algorithm for Modular Multilevel Converter Based Variable Speed Drive."
Proceedings - 2018 IEEE 18th International Conference on Power Electronics and Motion Control, PEMC 2018. United States: Institute of Electrical and Electronics Engineers Inc., 2018. 968-973.
AbstractModular Multilevel Converter (MMC) is one of the most promising topologies for high power-medium voltage application. However, the use of MMC in variable speed drive applications is still limited. This is due to the fact that the fluctuation of the submodules capacitor voltage is large at low speed constant torque operation. This paper proposes an improved balancing approach based on Space Vector Pulse Width Modulation (SVPWM). The proposed method uses only one SVPWM, which not only simplifies the calculation but also reduces the submodules capacitor fluctuation and the circulating current in the MMC, thereby allowing the operation of MMC-based variable speed drive over the entire operating speed range and improve the converter efficiency. The closed loop operation of the MMC-based variable speed drive is verified through extensive simulations.
Mudrov, Mikhail, Anatoliy Ziuzev, Konstantin Nesterov, and Stanimir Valtchev. "
Electric Drives Power-Hardware-in-the-Loop System Structures."
2018 20th European Conference on Power Electronics and Applications, EPE 2018 ECCE Europe. United States: Institute of Electrical and Electronics Engineers Inc., 2018.
AbstractPower-Hardware-in-the-Loop (PHiL) system for electric drives application based on power converter with Field Programmable Gate Array (FPGA)-based control system is discussed. PHiL structures are under discussion as well. During the PHiL mathematical model analysis instantaneous current repeating quality is increased. Variable frequency drive (VFD) was selected for testing.
Baikova, {E. N. }, L. Romba, R. Melicio, and {S. S. } Valtchev. "
Simulation and experiment on electric field emissions generated by wireless energy transfer."
Technological Innovation for Resilient Systems - 9th IFIP WG 5.5/SOCOLNET Advanced Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2018, Proceedings. Eds. {L. M. } Camarinha-Matos, {K. O. } Adu-Kankam, and M. Julashokri. IFIP Advances in Information and Communication Technology. Springer New York LLC, 2018. 243-251.
AbstractThis paper presents a wireless energy transfer (WET) system operating at the frequency of tens of kHz. It treats the modeling and simulation of WET prototype and its comparison with experimental measuring results. The wireless energy transfer system model was created to simulate the electric field between the emitting and the receiving coils, applying the finite element method. The results from the simulation are compared to the measured values of the electric field emission from the wireless energy transfer equipment. In the recent years the interest in the WET technology, especially for the electric vehicles (EV) batteries charging, is rapidly growing. The WET systems pollute the environment by electromagnetic emissions. Due to the expanding use of this technology in industrial and consumer electronics products, the problems associated with the electromagnetic compatibility (EMC), and the adverse impact on the human health becomes highly important.
Romba, L., {E. N. } Baikova, C. Borges, R. Melicio, and {S. S. } Valtchev. "
Wireless battery charger for EV with circular or planar coils: comparison."
Technological Innovation for Resilient Systems - 9th IFIP WG 5.5/SOCOLNET Advanced Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2018, Proceedings. Eds. {L. M. } Camarinha-Matos, {K. O. } Adu-Kankam, and M. Julashokri. IFIP Advances in Information and Communication Technology. Springer New York LLC, 2018. 214-223.
AbstractThis paper presents the experimental results obtained in the wireless energy transfer (WET) system prototype based on coils: circular or planar. With these experimental results we can choose the tuning settings to improve the efficiency of power transmission of the WET systems. In WET for electric vehicle batteries charging, the coil shape and the range between the coils are the most important issues of those systems.
Mar, Adriana, Fernando Monteiro, Pedro Pereira, and João Martins. "
An Application to Improve Smart Heritage City Experience."
Advances in Digital Cultural Heritage. Eds. Marinos Ioannides, João Martins, Roko Żarnić, and Veranika Lim. Cham: Springer International Publishing, 2018. 89-103.
AbstractNowadays technologies relate to so many aspects in our daily life that makes society eager for more and more ways of using it. To keep up with this new technological world, all economic sectors, from industry to services, are trying to adapt their products into this new reality. Presently, cultural heritage is already a field where the application of technology allows a static site to be converted into an intelligent environment, with detailed information about a specific monument or historical place, becoming more interesting, not only for local habitants, but also for tourists. This paper describes an application that allows tourists, managers and historical sites' habitants to experience a completely new way of discovering those places, offering a visit with detailed real-time information taking into account their personal interests. Tourists will have at their disposal a full set of optimized routes, combining their interests with their visiting time.
Roque, C., and H. Rocha Avaliação formativa com recurso à tecnologia [Formative assessment using technology]. SIEM. Almada, Portugal: APM, 2018.
AbstractThe present study aims to understand the potentialities and implications,
to the teacher and her practice, of the use of formative assessment with the support
of educational technology.
Regarding the research methodology, this study is part of the research on own
practice. The participants were the teacher, who was simultaneously a researcher,
and the students of a 9th grade class.
In the course of this experience it was found that the use of formative assessment
allows, on the one hand, the student to realize what he manages to understand, and
what he has to do to overcome what are less consolidated parts of the content in
study; and, on the other, the teacher to detect in a timely manner the difficulties of
the student and to change strategies to allow the student to overcome his difficulties.
The lack of time, the difficulties in managing the curriculum and the existence of
national exams are three of the main obstacles mentioned by the teachers for the
non-realization of formative assessment. In this experience it was found that the use
of new technologies turns possible to overcome these limitations.
This type of assessment had a very positive impact on teacher’s practice and in the
learning of the students.
Keywords: assessment; formative assessment; new technologies.