N.P. Papanikolaou

N.P. Papanikolaou
Democritus University of Thrace | DUTH · Department of Electrical and Computer Engineering

Associate Professor

About

104
Publications
52,509
Reads
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1,467
Citations
Additional affiliations
September 2013 - present
Democritus University of Thrace
Position
  • Professor (Assistant)
Description
  • Power Electronics
April 2008 - August 2013
Technological Educational Institute of Lamia
Position
  • Lecturer
Description
  • Power Electronics and Electric Drives
March 2004 - March 2008
Hellenic Transmission System Operator (HTSO S.A..)
Position
  • Engineer
Description
  • Hellenic Transmission System Design, ENTSO-E (former UCTE) coordination planning

Publications

Publications (104)
Article
Full-text available
Over recent years the output power of microinverters (ΜIC Module Incorporated Inverter) is progressively pushed to higher levels, following the current PV modules market trends. The interleaved Flyback inverter - under Discontinuous Conduction Mode of operation (DCM) - is an appealing solution for PV applications which are based on MIC technology....
Article
During the last decade, micro-inverters have gained a considerable share in residential PV systems’ market. However, in order to be accepted by the marketplace, the reliability of micro-inverters must be comparable with that of traditional PV string and multi string inverters. A typical reliability issue that these systems experience, particularly...
Article
Full-text available
The prescribed perspective of high accession of distributed generation photovoltaic (DG-PV) units on low-voltage distribution networks has brought up many issues regarding their performance in case of network transient phenomena. In this study, the design principles that DG-PV units must incorporate in order to meet the requirements of low-voltage...
Article
Full-text available
The issue of dc current injection at low voltage autonomous or interconnected grids as a result of photovoltaic (PV) systems integration is thoroughly discussed in this paper. This paper focuses on the sinusoidal pulsewidth modulation inverter with a low-frequency step-up transformer, as this was widely used in the past at PV grid connected applica...
Article
Full-text available
SRM is one of the most attractive electric machines to be used as a S/G in the future MEA thanks to its special physical characteristics that facilitate its direct coupling to the propulsive unit; however, the controllability of the SRG at different operational points, imposed by the specific application, is critical. In this paper, a novel active...
Article
Originally, ancillary services (ASs) were provided by large-scale power plants to ensure the secure and reliable operation of power systems. However, with the advent of renewable energy sources either in large-scale or as smaller distributed generation units, there is a strong need to revisit the structure and aim of traditional ASs and reconsider...
Technical Report
During RENERGISE, in order to increase system’s efficiency, we studied the introduction of two power generation units, which produce electrical power from waste heat, thanks to an energy recovery system. This power generation is used in replacement of or in addition to usual generation systems, which retrieve their power from the Main Gear Box (i.e...
Article
Full-text available
In the coming years, distribution grids will be progressively flooded by renewable energy sources (RES) that will be interconnected with the main grid through power electronic converters. Photovoltaics (PVs) are one of the most promising renewable technologies even for densely built‐up areas where space problems are inevitable. The high penetration...
Article
The building sector in Europe represents a large amount of the total energy consumption. European Union policies urge energy management systems installation in buildings, to achieve the nZEB targets and mitigate the climate change. Except for renewable energy sources, the incorporation of energy storage units (ESUs) is of major importance for build...
Article
Full-text available
This paper presents a transmitter side control scheme for a series-series compensated wireless power transfer (SS-WPT) system for electric vehicle (EV) charging applications. The proposed control scheme matches the reflected load impedance, by controlling accordingly the front-end dc-dc converter (FEC) of the SS-WPT system. The proposed control sch...
Conference Paper
Full-text available
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 droo...
Conference Paper
Full-text available
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...
Article
Full-text available
The objective of this paper is to present a power conversion system, based on a bidirectional DC/DC converter, along with a supercapacitor bank, that mitigates the voltage transients that occur on the DC distribution network of More/All Electric Aircrafts. These transients, such as voltage sags and swells appear on the DC buses of on-board microgri...
Poster
Dear colleagues, The open access journal Energies (ISSN 1996-1073, IF 2.702) is pleased to announce that we have launched a new Special Issue entitled "Power Electronics for Energy Saving." I am serving as Guest Editor for this issue. Given the depth of your expertise in this field, I would like to cordially invite you to contribute an article to...
Preprint
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 (i.e. a photovoltaic system, in combination with a micro cogeneration s...
Preprint
This study summarizes the current state-of-the-art regarding the SRM (Switched Reluctance Machine), as one of the most promising S/G (Starter/Generator) candidates to be aggregated in the high voltage (270 V or 540 V) DC-distribution system of the MEA (More Electric Aircraft). The machine operational principles, its fundamental technical parameters...
Poster
Full-text available
Various challenges are acknowledged in practical cases with massive renewables, like solar photovoltaic and wind, leading to the continuous revolution of grid-connection requirements. Power electronic converters, as the intermediate stage, are becoming more active in grid regulations, and now are more being integrated with energy storage. Design, o...
Article
Full-text available
Cost-effective energy saving in the building sector is a high priority in Europe; The European Union has set ambitious targets for buildings’ energy performance in order to convert old energy-intensive ones into nearly zero energy buildings (nZEBs). This study focuses on the implementation of a collective self-consumption nZEB concept in Mediterran...
Article
Full-text available
In this work the harmonic injection active anti-islanding technique that has been recently proposed in reference Voglitsis et al. (2018) published in Trans. Power Electron. is generalized under the prospect of a high penetration level of distributed energy resource (DER) installations. Towards this direction, the theoretical limitation for the pene...
Conference Paper
Full-text available
This paper investigates the synchronous buck DC/DC converter behavior, operating as a regulated current source (under peak current mode control) in the context of low voltage DC (LVDC) microgrids applications. A digital implementation scheme of the proposed control method is presented, based on TMS320F28027 microcontroller unit. The benefits of usi...
Conference Paper
Full-text available
This paper presents the analysis and design procedure of a low voltage, reconfigurable, on-chip DC/DC - DC/AC power conversion system for PV applications.The whole work is carried out in the context of a novel smart PV system development, which is based on integrated PV cell inverters. Various power converter topologies are investigated in order th...
Conference Paper
Full-text available
This study presents a control scheme for thermoelectric coolers (TECs), based on the implementation of a double PI control loop for supply current and ventilation regulation. A test bench was developed, including a thermal closet and all the necessary automation for data acquisition. Industrial thermocouples were employed in order to record the hea...
Article
Full-text available
The upcoming adoption of low-voltage-ride-through requirements in low-voltage distribution systems is expected to raise significant challenges in the operation of grid-tied inverters. Typically, these inverters interconnect photovoltaic units, which are the predominant distributed energy resource in low-voltage distribution networks, under an umbre...
Conference Paper
Full-text available
As the adoption of low-voltage-ride-through requirements for low-voltage distribution systems with distributed generators is under consideration, the fulfilment of these requirements should be examined not only as for the proper response of the generating units, but also regarding the selective operation of line protection means (fuses). Within thi...
Article
This work studies the significant impact of Distributed-Energy-Resource (DER) inverters (which are connected to the same node) on anti-islanding protection of DER-installations. As it concerns the harmonic injection-based schemes, the induced harmonic voltage component that is provoked by each inverter is compromised, as synchronous injection (inje...
Article
Full-text available
This paper investigates the Wireless Power Transfer (WPT) system incorporation into DC microgrids applications. Emphasis is given on the mathematical analysis of the Series-Series (SS) WPT system for Constant Voltage Source (CVS) loading conditions that cannot be effectively described by the equivalent constant resistance model. For this reason, th...
Article
Full-text available
Active anti-islanding schemes that are based on the injection of harmonic currents, such as the measurement of the impedance at a specific frequency or similar techniques, have been proposed for anti-islanding protection in photovoltaic (PV) systems due to their low impact on inverter active power, their fast detection response in island, and reduc...
Article
Full-text available
This work presents the first comprehensive study of active anti-islanding techniques suitable for Module Integrated Converters (MICs), which considers the high penetration level of PVs (or other Distribution Renewable Energy Sources, DRES) at low-voltage distribution networks. As such, the state of the art in anti-islanding methods are presented an...
Article
Full-text available
In this work, the electromechanical system of the 8000-series of Athens trolleybuses, based on data provided by OSY S.A., is analyzed. Those data were used to develop a valid model in order to estimate the total energy consumption of the vehicle under any possible operating conditions. In addition, an effort is made to estimate the energy saving po...
Conference Paper
Full-text available
This work presents the digital implementation of peak current control method in a bidirectional buck-boost DCDC converter, as an alternative solution to voltage and hysteresis mode control schemes. The advantages of peak current control, such as the constant switching frequency and good performance in both steady state and dynamic response are poin...
Article
Full-text available
This work introduces a new cross-correlation anti-islanding detection scheme for Module Integrated Converters with Pseudo dc-link (Pdc-MICs). The proposed scheme periodically injects a second order harmonic current component of low magnitude (in open-loop mode) and evaluates grid response by means of correlation. The proposed scheme is highly relia...
Conference Paper
Full-text available
This paper presents a comprehensive study of active anti-islandic techniques suitable for micro-inverters (MICs - Module Integrated Converters) which considers the high penetration level prospect of distributed PVs. In order to compare these methods under the same operating conditions and specifications, a benchmark is set based on zero Non-Detecti...
Conference Paper
The aim of this paper is to study the incorporation of the Wireless Power Transfer (WPT) into DC microgrids, by means of increasing the system reliability and reducing the installation complexity. In this context, the case of Series-Series (SS) compensated WPT system is studied, in order to interconnect distributed energy sources to the main DC bus...
Conference Paper
Full-text available
The scope of this paper is to investigate the accuracy of different low voltage energy meters for the recording of active and reactive energy of different load types. The low-voltage loads under consideration are single-and three-phase, with linear (resistive, inductive, capacitive) or non-linear behavior. Special emphasis is given on the influence...
Chapter
Electrical faults are best prevented by good design and the appropriate selection of system components coupled with careful installation-specific requirements of photovoltaic (PV) systems. PV arrays do not have a fixed voltage and current output, while they have the ability to produce and sustain electrical arcs with current values that are not sig...
Article
Full-text available
Standalone PV systems is a key technology for the increase of renewable energy sources share in electricity production worldwide. The power quality of those systems plays a fundamental role in avoiding volatile power supply. This calls for a concrete design in order to meet power quality specifications. In this context, a methodology has been devel...
Article
Full-text available
Motor drives is a widely used technology, offering many advantages such as exceptional speed control and flexibility. Improvement of reliability and efficiency has become a great research interest. Towards this direction and considering the major recent developments in supercapacitor technology, the use of bidirectional energy recovery converters h...
Article
Full-text available
This paper investigates energy efficiency issues in modern lifts, based on the VDI 4707 guidelines, in the context of “KLEEMANN-LESS” research project, funded by national resources and the EU. The above analysis is applied to various lift types manufactured by the Greek multinational company ΚLEEMAN HELLAS. The obtained results indicate the relatio...
Conference Paper
This paper analyses the existing protection scheme of a real distribution system with distributed generators, in Greece. Network protection utilizes three successive reclosers at the main trunk and fuses at the laterals. The generating units are protected by overcurrent and voltage/frequency relays. The analysis focuses on the fault-ride-through ca...
Article
The European Directive regarding the promotion of energy from renewable sources (Directive 2009/28 EC) specifies separate national targets for each member state of the EU community, in order at least 20% of EU total energy demands to be met by renewable energy sources by 2020. The analysis performed in this work highlights that grid connected photo...
Article
Full-text available
To increase the reliability of aerospace electronics and reduce their overall power consumption, we investigated the possibility of incorporating active thermo-electric cooling (TEC) solutions. The harsh avionic environment demands sophisticated active control schemes that enable the achievement of high coefficient of performance (COP). The positiv...
Conference Paper
Photovoltaic (PV) systems, due to their installation position, are exposed to direct and indirect lightning hits, which can damage the equipment of the system, resulting in interruption of the power supply, repair or/and replacement costs and dangers for the personnel. So, the implementation of an effective lightning protection system is a critical...
Article
Full-text available
The lightning protection of photovoltaic installations is of great importance, in order to warrant the uninterrupted operation of the system and avoid faults and damages of the equipment. Atmospheric discharges influence the proper operation of the photovoltaic generators and their installation, involving also sensitive electronic equipment. The de...
Chapter
The current work presents an overview of islanding detection techniques, highlighting their advantages and disadvantages. Generally, all anti-islanding techniques detect the absence of utility-controlled generation and stop energy production. However, when the generation (from PVs) and loads within the island segment are well balanced—prior to the...
Article
The Distributed Generation expansion and its smooth integration in distribution networks have gained much interest over the last years. Particularly, the photovoltaic systems connected to the low voltage distribution networks, present noteworthy benefits for the energy markets and customers. Meanwhile, aiming to high penetration level, many issues...
Conference Paper
Full-text available
Several types of energy recovery systems (i.e. shaft generators etc.) have been installed in marine vessels, in order to reduce the fuel consumption and ultimately improve the efficiency of the vessels. In this paper, an energy recovery system utilizing the thermal losses of a real ship is investigated. The main goal of this work is to improve the...
Conference Paper
Full-text available
The grid-tied low voltage photovoltaics are expanded day by day. Aiming for a high penetration level, the Fault Ride Through Capability (FRTC) standard should be extended to these units as well. In this paper, the behavior of Single Phase Grid Connected PV Systems under faulty conditions is investigated. For this purpose, a SPWM controlled full bri...
Conference Paper
Full-text available
Photovoltaic (PV) systems, due to their installation position, are exposed to lightning discharges, which can damage their equipment (PV modules, inverters, etc.), resulting malfunctions on the entire system, high repair costs and financial losses. The severity of the lightning consequences depends on the characteristics of the lightning current wa...
Conference Paper
Common variable speed drives usually do not feature regenerative braking. The energy produced during deceleration is dissipated through braking resistors. In this paper, a bidirectional converter designed for use with variable speed drives, adding the capability of regenerative braking, is presented. Hardware design and control algorithms are an...
Article
Full-text available
In this work, a novel performance analysis method for evaluating the robustness of emerging power distribution networks (PDNs), which involve deployable renewable energy sources, is proposed. This is realized with the aid of the outage probability (OP) criterion in the context of cooperative communications, which is widely considered in modern wire...
Conference Paper
Reliability is one of the most important parameters in aircrafts. In this paper, a method for the calculation of reliability (i.e. number of failures / 106 hours) of a three-phase full-bridge inverter, which is employed in the dynamic waste heat recovery system of an aircraft, is presented. The main factors for the reliability analysis that have to...
Article
Full-text available
The increasing electrical energy price worldwide and generally the liberation of Electrical Energy Markets, has highlighted the standalone residential PV systems as a potentially viable commercial product, especially for remote areas (islands, rural territories etc). Critical values for the success of these systems are the initial required capital...
Conference Paper
Full-text available
This paper discusses the optimal combination of the thermoelectric generation concept in building applied PV panels, in order to recover additional electric energy amounts by the waste heat. Moreover, since this concept refers to build-ing applications, the combination of geothermal energy will be also investigated. An insightful study of all its t...
Conference Paper
Full-text available
This paper presents two different approaches for the incorporation of commercial inverters in ships’ low voltage electric network, either for the exploitation of renewable sources such as the sun and the wind, or for energy regeneration from the exhaust gases heat. Both solutions contribute to the reduction of CO2 emissions as well as to fuel consu...
Conference Paper
In this work, an active regenerative braking converter using a bidirectional Buck-Boost converter is implemented in order to improve the overall efficiency of modern building lifts. The converter is connected in parallel to the inverter DC-bus. Energy is stored in a set of supercapacitors during regeneration and it is transferred back to the DC-bus...