Please login first
Carmen A. Bulucea  - - - 
Top co-authors
Marc A. Rosen

439 shared publications

Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, Oshawa, ON L1G 0C5, Canada

Doru A. Nicola

5 shared publications

University of Craiova, Faculty of Electrical Engineering, Craiova 200440, Romania

Nikos E. Mastorakis

5 shared publications

Technical University of Sofia, English Language Faculty of Engineering, Sofia 1000, Bulgaria

6
Publications
0
Reads
0
Downloads
3
Citations
Publication Record
Distribution of Articles published per year 
(2012 - 2018)
Total number of journals
published in
 
4
 
Publications
Article 0 Reads 0 Citations Evaluating through mathematical modelling the power equipment busbars electrodynamic strength under sudden short-circuit... Cornelia A. Bulucea, Constantin Brindusa, Doru A. Nicola, Ni... Published: 01 January 2018
MATEC Web of Conferences, doi: 10.1051/matecconf/201821002004
DOI See at publisher website
Article 6 Reads 0 Citations Operation analysis of AC traction motors in terms of electromagnetic torque capability on sustainable railway vehicles Cornelia A. Bulucea, Doru A. Nicola, Marc A. Rosen, Nikos E.... Published: 21 October 2016
MATEC Web of Conferences, doi: 10.1051/matecconf/20167602005
DOI See at publisher website ABS Show/hide abstract
Sustainable operation of electric railway systems represents a significant purpose nowadays in the development of high power and high speed locomotives and trains. At present, high speed electric vehicles mostly work with three-phase induction motors or three-phase synchronous motors as traction motors. The two electric machine types have different efficiencies at different operation points, and experience differences with respect to safety, speed and power, energy use and exergy efficiency. An important issue that correlates these aspects is the electromagnetic torque developed by an electric traction motor. In order to provide an overview of the technical performance of the operation of sustainable railway systems, a detailed analysis is carried out of the electromagnetic torque capability of AC electric motors utilized as traction motors in modern locomotives of high power and/or high speed. The results of this work may help in enhancing the main criteria for optimising the safe and sustainable operation of electric railway traction systems.
PROCEEDINGS-ARTICLE 9 Reads 0 Citations Some Aspects of Sustainable Energy Conversion During Transient Processes in Electric Power Systems Comprising Generator ... Cornelia Bulucea, Marc Rosen, Doru Nicola, Nikos Mastorakis,... Published: 31 October 2013
Proceedings of The 3rd World Sustainability Forum, doi: 10.3390/wsf3-d001
DOI See at publisher website ABS Show/hide abstract
This paper is a sequel to a study by the authors of the electric power systems comprising the generator circuit-breakers (GCBs) at power plant generator terminals. A sustainable assessment of the current interruption requirements of a GCB addresses the main stresses on the generator circuit breaker, revealing that the GCB current interruption requirements are significantly higher than for the distribution network circuit breakers. Hence, generator circuit-breakers are subject to unique demanding conditions caused my specific stresses, namely: high asymmetrical fault currents resulting from high d.c. components of the fault current; greater electrical, thermal and mechanical stresses when interrupting longer arcing time faults; and important dielectric stress after the electric arc extinction caused by the transient recovery voltage (TRV). This paper extends other studies of the authors of the energetic and exergetic transformation chain at the interruption current transient process in an electric power system that comprises the generator circuit-breaker, as well as the transient recovery voltage (TRV) which appears after the interruption of a short-circuit fed by the synchronous generator or by the main step-up transformer. For achieving the TRV equivalent configuration the authors applied the method of operational symmetrical components (o.s.c.), and utilized the operational impedances of synchronous generator and of main transformer, depending on the fault location. Modeling the transient recovery voltage of circuits emphasizes aspects with direct implications on commutation equipment. Thus, the o.s.c. method can be applied at the poles of any breaker, for any eliminated fault type, if the network configuration and elements are known. The TRV, which appears after the interruption of a short-circuit fed by the generator, may be considered like an oscillation, where the oscillation factor and the rising rate (RR) of the TRV are established by the electrical machine parameters: resistance, inductance and capacitance. Consequently, modeling of concentrated equivalent parameters of the synchronous generator at perturbations caused by current interruption transient processes is achieved in this study through an approach based on sustainability concepts. These findings allow for simulations of the transient recovery voltage and comparisons with experimental results.
Article 0 Reads 2 Citations Approaching the Processes in the Generator Circuit Breaker at Disconnection through Sustainability Concepts Cornelia A. Bulucea, Marc A. Rosen, Doru A. Nicola, Nikos E.... Published: 19 March 2013
Sustainability, doi: 10.3390/su5031161
DOI See at publisher website ABS Show/hide abstract
Nowadays, the electric connection circuits of power plants (based on fossil fuels as well as renewable sources) entail generator circuit-breakers (GCBs) at the generator terminals, since the presence of that electric equipment offers many advantages related to the sustainability of a power plant. In an alternating current (a.c.) circuit the interruption of a short circuit is performed by the circuit-breaker at the natural passing through zero of the short-circuit current. During the current interruption, an electric arc is generated between the opened contacts of the circuit-breaker. This arc must be cooled and extinguished in a controlled way. Since the synchronous generator stator can flow via highly asymmetrical short-circuit currents, the phenomena which occur in the case of short-circuit currents interruption determine the main stresses of the generator circuit-breaker; the current interruption requirements of a GCB are significantly higher than for the distribution network circuit breakers. For shedding light on the proper moment when the generator circuit-breaker must operate, using the space phasor of the short-circuit currents, the time expression to the first zero passing of the short-circuit current is determined. Here, the manner is investigated in which various factors influence the delay of the zero passing of the short-circuit current. It is shown that the delay time is influenced by the synchronous machine parameters and by the load conditions which precede the short-circuit. Numerical simulations were conducted of the asymmetrical currents in the case of the sudden three-phase short circuit at the terminals of synchronous generators. Further in this study it is emphasized that although the phenomena produced in the electric arc at the terminals of the circuit-breaker are complicated and not completely explained, the concept of exergy is useful in understanding the physical phenomena. The article points out that just after the short-circuit current interruption by the generator the circuit-breaker (when the GCB has been subjected at the metal contact terminals to the high temperature of a plasma arc, up to 50,000 K) between its opened contacts, there arises the transient recovery voltage (TRV) which constitutes the most important dielectric stress after the electric arc extinction. Since the magnitude and shape of the TRV occurring across the generator circuit-breaker are critical parameters in the recovering gap after the current zero, in this paper, we model, for the case of the faults fed by the main step-up transformer, the equivalent configurations, with operational impedances, for the TRV calculation, taking into account the main transformer parameters, on the basis of the symmetrical components method.
Article 4 Reads 0 Citations Utilizing the Exergy Concept to Address Environmental Challenges of Electric Systems Cornelia A. Bulucea, Marc A. Rosen, Doru A. Nicola, Nikos E.... Published: 11 October 2012
Entropy, doi: 10.3390/e14101894
DOI See at publisher website ABS Show/hide abstract
Theoretically, the concepts of energy, entropy, exergy and embodied energy are founded in the fields of thermodynamics and physics. Yet, over decades these concepts have been applied in numerous fields of science and engineering, playing a key role in the analysis of processes, systems and devices in which energy transfers and energy transformations occur. The research reported here aims to demonstrate, in terms of sustainability, the usefulness of the embodied energy and exergy concepts for analyzing electric devices which convert energy, particularly the electromagnet. This study relies on a dualist view, incorporating technical and environmental dimensions. The information provided by energy assessments is shown to be less useful than that provided by exergy and prone to be misleading. The electromagnet force and torque (representing the driving force of output exergy), accepted as both environmental and technical quantities, are expressed as a function of the electric current and the magnetic field, supporting the view of the necessity of discerning interrelations between science and the environment. This research suggests that a useful step in assessing the viability of electric devices in concert with ecological systems might be to view the magnetic flux density B and the electric current intensity I as environmental parameters. In line with this idea the study encompasses an overview of potential human health risks and effects of extremely low frequency electromagnetic fields (ELF EMFs) caused by the operation of electric systems. It is concluded that exergy has a significant role to play in evaluating and increasing the efficiencies of electrical technologies and systems. This article also aims to demonstrate the need for joint efforts by researchers in electric and environmental engineering, and in medicine and health fields, for enhancing knowledge of the impacts of environmental ELF EMFs on humans and other life forms.
Article 0 Reads 1 Citation Approaching Resonant Absorption of Environmental Xenobiotics Harmonic Oscillation by Linear Structures Cornelia A. Bulucea, Marc A. Rosen, Nikos E. Mastorakis, Car... Published: 30 March 2012
Sustainability, doi: 10.3390/su4040561
DOI See at publisher website ABS Show/hide abstract
Over the last several decades, it has become increasingly accepted that the term xenobiotic relates to environmental impact, since environmental xenobiotics are understood to be substances foreign to a biological system, which did not exist in nature before their synthesis by humans. In this context, xenobiotics are persistent pollutants such as dioxins and polychlorinated biphenyls, as well as plastics and pesticides. Dangerous and unstable situations can result from the presence of environmental xenobiotics since their harmful effects on humans and ecosystems are often unpredictable. For instance, the immune system is extremely vulnerable and sensitive to modulation by environmental xenobitics. Various experimental assays could be performed to ascertain the immunotoxic potential of environmental xenobiotics, taking into account genetic factors, the route of xenobiotic penetration, and the amount and duration of exposure, as well as the wave shape of the xenobiotic. In this paper, we propose an approach for the analysis of xenobiotic metabolism using mathematical models and corresponding methods. This study focuses on a pattern depicting mathematically modeled processes of resonant absorption of a xenobiotic harmonic oscillation by an organism modulated as an absorbing oscillator structure. We represent the xenobiotic concentration degree through a spatial concentration vector, and we model and simulate the oscillating regime of environmental xenobiotic absorption. It is anticipated that the results could be used to facilitate the assessment of the processes of environmental xenobiotic absorption, distribution, biotransformation and removal within the framework of compartmental analysis, by establishing appropriate mathematical models and simulations.
Top