@uoa.gr
National and Kapodistrian University of Athens
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Symeon Fountoukidis, Nick Rigogiannis, Georgios Voltsis, Konstantinos Terzopoulos, Michael Loupis, and Nikolaos Papanikolaou
MDPI
Alejandro Gonzalez-Ollauri, Slobodan B. Mickovski, Carl C. Anderson, Sisay Debele, Rohinton Emmanuel, Prashant Kumar, Michael Loupis, Joy Ommer, Jan Pfeiffer, Depy Panga,et al.
Elsevier BV
Nick Rigogiannis, Ioannis Bogatsis, Christos Pechlivanis, Konstantinos Terzopoulos, Anastasios Kyritsis, Nick Papanikolaou, and Michael Loupis
IEEE
A flexible Power Monitoring System (PMS) is presented in this paper. This PMS is installed in the electric power distribution network of a ferry-boat, which is essentially an autonomous microgrid. Its scope is to collect real-time voltage/current measurements from various selected points of the shipboard microgrid, so as to monitor the power flow and obtain power quality metrics (e.g., harmonics, voltage dips etc.), by the aid of power analyzers and data loggers. At first, the electrical installation of the studied vessel is described in detail, along with electricity consumption data and a classification of the most significant loads. Next, each individual component of the installed PMS (i.e., Rogowski coils, data loggers, power analyzers, interfaces etc.) is presented and analyzed. Finally, the data obtained by the power meters are processed, leading to notable conclusions regarding the power quality of the electricity supplied to various loads, indicating possible sources of power quality degradation.
Symeon Fountoukidis, Nick Rigogiannis, Nick Papanikolaou, and Michael Loupis
IEEE
The objective of this paper is to present the control loop design of the I2t curve in the concept of Solid-State Circuit Breakers (SSCBs), which are applicable to the DC distribution network of the More Electric Aircraft (MEA). The proposed control scheme lies upon the introduction of a tripping time, in order either to avoid unnecessary circuit breakings. Moreover, the current breaking capability is tested through a simulation model by the aid of PLECS software and through an experimental scaled down test-bench. Finally, the current limiting strategy (i.e., the I2t curve) is digitally implemented by the aid of a microcontroller unit (i.e., TMS320F28379D).
Nick Rigogiannis, Ioannis Roussos, Christos Pechlivanis, Ioannis Bogatsis, Anastasios Kyritsis, Nick Papanikolaou, and Michael Loupis
IEEE
The incorporation of a waste heat recovery system, based on thermoelectric generator modules, in a shipboard microgrid is studied in this paper. Various voltage boosting topologies are discussed and the most appropriate ones are evaluated through the LTspice simulation platform. The design process of the selected LLC resonant converter topology is presented and discussed in detail. In parallel, a flexible control scheme is proposed, capable of either maximum power tracking, or constant voltage (i.e., output voltage regulation) operation, in respect to the load demands. Finally, simulation results indicate the high efficiency that can be achieved with the proposed converter for a wide operating range, as well as the functionality and performance of the controller, in both operating modes.
Christos Spyrou, Michael Loupis, Nikos Charizopoulos, Panagiotis Arvanitis, Angeliki Mentzafou, Elias Dimitriou, Sisay E. Debele, Jeetendra Sahani, and Prashant Kumar
MDPI AG
A number of Nature Based Solutions (NBS) are being used around the world in order to address various hydrometeorological hazards as a more environmentally friendly alternative to hard structures. Such a solution has been created in the Spercheios river basin in Central Greece, which is susceptible to heavy rainfall and river bank overflow due to flood water from upstream, in order to mitigate flood and drought impacts under current and future climate conditions. Here a first attempt is made to use actual measurements taken from various sources in the river, including in-situ and satellite data, in order to establish early experimental evidence of the NBS efficiency in the area. The measurements include data from automated hydrological stations from the OpenHi network, satellite remote sensing data and field measurements performed along the Spercheios River basin. For each measurement used, different analysis has been performed based on data availability and pertinence to the NBS efficiency. Preliminary results presented here show that the NBS functions as designed and provides protection against flooding in the area, and can potentially diminish the risk of drought. The results are in agreement with the numerical outputs already presented in our previous work.
Carl C. Anderson, Fabrice G. Renaud, Stuart Hanscomb, Karen E. Munro, Alejandro Gonzalez-Ollauri, Craig S. Thomson, Eija Pouta, Katriina Soini, Michael Loupis, Depy Panga,et al.
Frontiers Media SA
School of Interdisciplinary Studies, University of Glasgow, Dumfries, United Kingdom, The BEAM Research Centre, School of Computing, Engineering and Built Environment, Glasgow Caledonian University, Glasgow, United Kingdom, Natural Resources Institute Finland (Luke), Helsinki, Finland, Innovative Technologies Centre, Athens, Greece, General Department, National and Kapodistrian University of Athens, Athens, Greece
Nena Apostolidou, Fotis Valsamas, Dimitris Baros, Michael Loupis, Vasilios Dasteridis, and Charalampos Kokkinis
MDPI AG
In this work, the development of an energy recovery control unit to be incorporated in the light-emitting diodes (LEDs) lighting systems of heavy-duty vehicles is presented. This innovative industrial product adopts modern power electronics technology to improve existing trucks’ LED lighting system by eliminating the so far inevitable power consumption by the conventional central control unit of the majority of these vehicles, which is obligatory for the uninterruptable operation of their lighting system. The main idea of this innovative product is its capability to virtually increase the lighting system power consumption without actually consuming this amount of energy, thus facilitating the central control unit requirements regarding these vehicles in an energy-conscious way. Under this light, a mature power converter’s topology is employed to draw the proper amounts of power from the vehicle’s batteries supply, to the level that the central control unit recognizes, and return this energy back to the batteries. The tests results of the developed industrial product highlight the energy saving potential of the proposed energy recovery scheme, while the Life Cycle Cost Analysis (LCCA) results confirm its techno-economical and environmental profit for the truck applications under study.
Prashant Kumar, Sisay E. Debele, Jeetendra Sahani, Nidhi Rawat, Belen Marti-Cardona, Silvia Maria Alfieri, Bidroha Basu, Arunima Sarkar Basu, Paul Bowyer, Nikos Charizopoulos,et al.
Elsevier BV
Carl C. Anderson, Fabrice G. Renaud, Stuart Hanscomb, Karen E. Munro, Alejandro Gonzalez-Ollauri, Craig S. Thomson, Eija Pouta, Katriina Soini, Michael Loupis, Depy Panga,et al.
Frontiers Media SA
Climate change is one factor increasing the risk of hydro-meteorological hazards globally. The use of nature-based solutions (NbS), and more specifically ecosystem-based disaster risk reduction measures (Eco-DRR), has become a popular response for risk reduction that also provides highly-valued co-benefits. Public acceptance is of particular importance for NbS since they often rely on local collaborative implementation, management, and monitoring, as well as long-term protection against competing societal interests. Although public engagement is a common goal of NbS projects, it is rarely carried out with a sufficient understanding of the (de)motivating factors tied to public perceptions. Successful collaboration demands consideration of societal attitudes and values in relation to risk, nature, and place. However, existing research does not sufficiently explore these themes together, their interactions, and their implications for the public acceptance of NbS. This may lead to misaligned public expectations and failed participatory initiatives, while jeopardizing the success of NbS projects and their continued funding and uptake. We conducted citizen surveys within local NbS “host” communities to determine the degree of pro-NbS attitudes and behavior, associated variables, and how these may be leveraged to increase acceptance. We compared results across sites, relying primarily on correlations and regression models along with survey comments and expert knowledge. Three distinct rural NbS being implemented within the OPERANDUM project aim to reduce risk from (socio-)natural hazards in Scotland (landslides and coastal erosion; n = 66 respondents), Finland (eutrophication and algal blooms; n = 204) and Greece (river flooding and water scarcity; n = 84). Our research thus centers on rural NbS for risk reduction within a large EU project. Trust in implementers is a consistent factor for defining attitudes towards the NbS across the sites, and attitudes are strongly associated with respondents’ commitment to nature and behavioral acceptance (i.e., willingness to engage). Behaviorial acceptance is most consistently predicted by connectedness to place and the extent of expected future impacts. Skepticism of NbS effectiveness leads to high public demand for relevant evidence. To increase public acceptance, we recommend greater framing of NbS in relation to place-based values as well as demonstration of the effectiveness of NbS for risk reduction. However, distinct hazard types, proposed NbS, and historical characteristics must be considered for developing strategies aimed at increasing acceptance. An understanding of these characteristics and their interactions leads to evidence-based recommendations for our study sites and for successful NbS deployment in Europe and beyond.
Prashant Kumar, Sisay E. Debele, Jeetendra Sahani, Nidhi Rawat, Belen Marti-Cardona, Silvia Maria Alfieri, Bidroha Basu, Arunima Sarkar Basu, Paul Bowyer, Nikos Charizopoulos,et al.
Elsevier BV
Abstract To bring to fruition the capability of nature-based solutions (NBS) in mitigating hydro-meteorological risks (HMRs) and facilitate their widespread uptake require a consolidated knowledge-base related to their monitoring methods, efficiency, functioning and the ecosystem services they provide. We attempt to fill this knowledge gap by reviewing and compiling the existing scientific literature on methods, including ground-based measurements (e.g. gauging stations, wireless sensor network) and remote sensing observations (e.g. from topographic LiDAR, multispectral and radar sensors) that have been used and/or can be relevant to monitor the performance of NBS against five HMRs: floods, droughts, heatwaves, landslides, and storm surges and coastal erosion. These can allow the mapping of the risks and impacts of the specific hydro-meteorological events. We found that the selection and application of monitoring methods mostly rely on the particular NBS being monitored, resource availability (e.g. time, budget, space) and type of HMRs. No standalone method currently exists that can allow monitoring the performance of NBS in its broadest view. However, equipments, tools and technologies developed for other purposes, such as for ground-based measurements and atmospheric observations, can be applied to accurately monitor the performance of NBS to mitigate HMRs. We also focused on the capabilities of passive and active remote sensing, pointing out their associated opportunities and difficulties for NBS monitoring application. We conclude that the advancement in airborne and satellite-based remote sensing technology has signified a leap in the systematic monitoring of NBS performance, as well as provided a robust way for the spatial and temporal comparison of NBS intervention versus its absence. This improved performance measurement can support the evaluation of existing uncertainty and scepticism in selecting NBS over the artificially built concrete structures or grey approaches by addressing the questions of performance precariousness. Remote sensing technical developments, however, take time to shift toward a state of operational readiness for monitoring the progress of NBS in place (e.g. green NBS growth rate, their changes and effectiveness through time). More research is required to develop a holistic approach, which could routinely and continually monitor the performance of NBS over a large scale of intervention. This performance evaluation could increase the ecological and socio-economic benefits of NBS, and also create high levels of their acceptance and confidence by overcoming potential scepticism of NBS implementations.
Christos Spyrou, Michael Loupis, Νikos Charizopoulos, Ilektra Apostolidou, Angeliki Mentzafou, George Varlas, Anastasios Papadopoulos, Elias Dimitriou, Depy Panga, Lamprini Gkeka,et al.
MDPI AG
Nature-based solutions (NBS) are being deployed around the world in order to address hydrometeorological hazards, including flooding, droughts, landslides and many others. The term refers to techniques inspired, supported and copied from nature, avoiding large constructions and other harmful interventions. In this work the development and evaluation of an NBS applied to the Spercheios river basin in Central Greece is presented. The river is susceptible to heavy rainfall and bank overflow, therefore the intervention selected is a natural water retention measure that aims to moderate the impact of flooding and drought in the area. After the deployment of the NBS, we examine the benefits under current and future climate conditions, using various climate change scenarios. Even though the NBS deployed is small compared to the rest of the river, its presence leads to a decrease in the maximum depth of flooding, maximum velocity and smaller flooded areas. Regarding the subsurface/groundwater storage under current and future climate change and weather conditions, the NBS construction seems to favor long-term groundwater recharge.
Nena Apostolidou, Nick Papanikolaou, and Michael Loupis
IEEE
This study summarizes the current state-of-the-art regarding the switched reluctance machine (SRM), as one of the most promising starter/generator (S/G) candidates to be aggregated in the high voltage (270 V or 540 V) DC distribution system of the more electric aircraft (MEA). The machine operational principles, its fundamental technical parameters regarding the specific application and the proposed control schemes are presented.
Dimitris Baros, Nick Rigogiannis, Nick Papanikolaou, and Michael Loupis
IEEE
This work aims to investigate the effects of communication delay in a DC microgrid, which operates under an adaptive droop control scheme. A case study of a residential DC microgrid is examined, which is essentially a household prosumer with power generation units, both on site and remotely, energy storage units and various loads. Conventional droop control schemes have been widely adopted in DC microgrids, although they cause voltage deviation, due to the different characteristics of generation units, whereas their performance is sensitive to line impedances. In order to compensate this deviation, while maintaining current sharing accuracy (adapting to line impedances), a distributed secondary controller is considered, which regards only the information of neighboring converters, by the aid of digital communication links. The impact of various communication methods, in terms of communication delay is examined and evaluated via MATLAB/Simulink simulations.
Mohammad Aminur Rahman Shah, Fabrice G. Renaud, Carl C. Anderson, Annie Wild, Alessio Domeneghetti, Annemarie Polderman, Athanasios Votsis, Beatrice Pulvirenti, Bidroha Basu, Craig Thomson,et al.
Elsevier BV
Prashant Kumar, Sisay E. Debele, Jeetendra Sahani, Leonardo Aragão, Francesca Barisani, Bidroha Basu, Edoardo Bucchignani, Nikos Charizopoulos, Silvana Di Sabatino, Alessio Domeneghetti,et al.
Elsevier BV
Jeetendra Sahani, Prashant Kumar, Sisay Debele, Christos Spyrou, Michael Loupis, Leonardo Aragão, Federico Porcù, Mohammad Aminur Rahman Shah, and Silvana Di Sabatino
Elsevier BV
Charalampos Tsioustas and Michael Loupis
IEEE
Ν. Papanikolaou, M. Loupis, Ν. Spiropoulos, Ε. Mitronikas, Ε. Τatakis, C. Christodoulou, V. Zarikas, and T. Τsiftsis
Springer Science and Business Media LLC
Emmanuel Karampasis, Nick Papanikolaou, Dionisis Voglitsis, Michael Loupis, Anastasios Psarras, Alexandros Boubaris, Dimitris Baros, and Giorgos Dimitrakopoulos
Institute of Electrical and Electronics Engineers (IEEE)
Mirjana Pejić Bach, Jovana Zoroja, and Michalis Loupis
SAGE Publications
Alireza Bagheri, Paschalis C. Sofotasios, Theodoros A. Tsiftsis, Khuong Ho-Van, Michael I. Loupis, Steven Freear, and Mikko Valkama
IEEE
Theodoros A. TSIFTSIS, Paschalis C. SOFOTASIOS, Nick PAPANIKOLAOU, and Michael I. LOUPIS
Springer Science and Business Media LLC
Charoula G. Zogogianni, Dionisis Voglitsis, Stefanos Saridakis, Stylianos P. Syrigos, Nick P. Papanikolaou, Anastasios Kyritsis, Michael Loupis, Theodoros A. Tsiftsis, and Emmanuel C. Tatakis
IEEE