Petros Karaisas

Petros Karaisas
University of West Attica | TEIATH · Department of Electrical Engineering

phd

About

33
Publications
9,681
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61
Citations
Citations since 2017
10 Research Items
42 Citations
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2017201820192020202120222023024681012
2017201820192020202120222023024681012
2017201820192020202120222023024681012

Publications

Publications (33)
Conference Paper
Full-text available
Detecting and locating faults in LEC cables is a complex activity that basically involves conducting measurements and controlling the cable or tracking the indications of the measuring and signaling equipment during the switching operations performed during the fault detection. The fault type and its location are determined by specialized equipment...
Conference Paper
Full-text available
It is well known the actual trend in power electronics to change power thyristors with devices which are more flexible from the point of view of commutation and control possibilities (IGBTs, MOS transistors, GTOs). For several existing applications, like DC high voltage electric power transmission for instance, where power commutation is involved,...
Conference Paper
Full-text available
Conference Paper
The content of space harmonics in axial-flux permanent-magnet machines (AFPMMs) is an important concern to the machine designer due to its impact on the performance. In AFPMMs, the harmonics are related to the flux-density and the MMF distributions in the air gap, which are mainly determined by the permanent- magnet excitation. This paper proposes...
Conference Paper
The paper analyzes an EMI filtering solution to diminish the effect of harmonics generated by PWM converters in active filters. Throughout this paper, a few specific problems regarding the design, simulation and validation of the model by testing EMI filters are presented. It can be mentioned that the tests of the experimental model were performed...
Conference Paper
The stability of a power system is determined by the dynamics of its interconnected synchronous machines. Hence, the study and analysis of the steady-state and the dynamic behaviors of the power system depend highly on the synchronous machine modeling. Dynamic analysis of synchronous machines is of great importance to show how all control and prote...
Article
Full-text available
The paper deals with the vibroacoustic perturbations issues, generated by the induction electric motors and brushless in residential environment. Two situations are analyzed: one in the componence of a chiller, used in the generation of thermal agent, and the other in the componence of an air handling unit, both destined to reach ambient comfort. T...
Conference Paper
Water resource availability is an important problem as water is basically used for everything we make. In a water distribution process the level and flow must be always controlled. Therefore, the parameters of the system must be known at any moment. This paper presents an automatic level control system which is analyzed in terms of reliability in o...
Conference Paper
Full-text available
In this paper, divergences are identified concerning the elimination/limitation technique of the produced higher order harmonics in traction systems, via experimental results. A simulation of a multi-winding transformer carried out, based on real data derived from measurements in a DC traction substation, by using the PSCAD/EMTDC simulation softwar...
Article
Full-text available
Wave energy is an important renewable source of electricity that can be exploited. The reliability is an important issue for these energy converters due to the fact that they must be installed in harsh environments. The paper presents a reliability analysis of the linear generator type wave energy converters and shows the impact of the environment...
Conference Paper
Wave energy is an important renewable source of electricity that can be exploited. The reliability is an important issue for these energy converters due to the fact that they must be installed in harsh environments. The paper presents a reliability analysis of the linear generator type wave energy converters and shows the impact of the environment...
Article
Full-text available
Quality is an important factor in today’s consumer market as there are numerous products available, but only a small percentage that can be considered as reliable. The paper presents an overview on the concept of quality, it’s relation with reliability and how companies can provide good quality products. As a case study, it presents an analysis of...
Research
Full-text available
The development of renewable energy sources calls for standards concerning the quality of the power injected into the power grid. One aspect that needs to be considered in the use of classic filters , but at the same time, it has to perform like insertion loss, for the common mode, but also for the differential mode. Conformity testing for conducte...
Conference Paper
Full-text available
The physicochemical process during the operation of fusible wires under high currents densities presents complicity and seems not to be completely known. The work presented in this paper investigates the resistivity variation during fusion process of exploding wires using common industrial power supply directly feed from the network of 50Hz. The me...
Conference Paper
Full-text available
The physicochemical process during the operation of fusible wires under high currents densities presents complicity and seems not to be completely known. According to the related literature, there is magnetic pressure involved in the process during pre-arcing and possibly during arcing periods. In this paper, the investigation of this physical quan...
Article
Full-text available
In October 2012, the Commission published a proposal to limit global land conversion for biofuel production, and raise the climate benefits of biofuels used in the European Union (EU). The use of food-based biofuels to meet 10% renewable energy target of the Renewable Energy Directive will be limited to 5%. This decision was made in order to stimul...
Chapter
In this paper is presented the implementation of a software for the analysis of vibration generated by wind turbines components. This software application was built in LabWiew programming environment and for vibration analysis and fault detection were used techniques as: wavelet analysis, envelope detection, FFT analysis, Cepstrum analysis, Vector...
Article
Full-text available
This paper develops a model based on an original lumped-parameter network configuration for the thermal transient analysis of a permanent magnet synchronous motor (PMSM). The specific PMSM was designed and optimized for a demanding aerospace application. The validity of the proposed lumped-parameter model is verified by measurements carried out in...
Chapter
The paper reviews the main faults identification of electric machines based on amplitude versus time and amplitude versus frequency vibration analysis. The aim of the paper is to introduce a new method in determining rotor faults based on stator vibration. The analysis method uses a multi-channel vibration analyzer provided with three accelerometer...
Conference Paper
Full-text available
The paper presents the implementation of a software for the analysis of vibration generated by wind turbines components. This software application has been built in the LabVIEW programming environment. For the vibration analysis and fault detection have been used several techniques, like: wavelet analysis, envelope detection, FFT analysis, Cepstrum...
Conference Paper
Full-text available
EMI - Electro Magnetic Interference-filtering represents an anti-distortion measure used in the mitigation of the conducted interference, i.e. electromagnetic perturbations on the supply cord, data or signal lines. The paper reviews the design of the magnetic circuit of a three-phase EMI filter, neglecting the displacement current. The designed EMI...
Conference Paper
Full-text available
This paper presents a method for limiting short-circuit current for d.c. systems. Classic methods for limiting short-circuit current are described as well as solid state devices used directly on current path and by-pass solutions. Thyristor and resonant circuit breaker version proposed by authors relieves current flow for every step during operatio...
Conference Paper
Full-text available
The paper presents some issues on testing the generators, integrated in wind turbine systems. Generators are subject to perturbations transmitted from the source to the source and to perturbations determined by the variable speed of the turbines' blades. The paper reviews the standards concerning tests in wind systems and depicts some specific test...
Article
Full-text available
The paper presents a possibility of supplying the electromagnetic vibrators with variable frequency voltage. Two types of modulated controls of the inverter’s commutation angle are presented. The theoretical analysis allows the study of the variable element influence on the distortion factor and of the harmonic content generated by the vibrator. Th...
Conference Paper
Full-text available
The analysis of the electrical machines operation, usually appeals to monitoring and diagnosis techniques, the operation faults involving electrical, mechanical and aerodynamical parameters modification. The mechanical faults are due mainly to the unbalance of the rotating parts of the electrical machines and their analysis can be carried out using...
Article
Full-text available
Due to climate changes that have been observed in regions all over the world and which are believed to be caused by the use of conventional energy sources, we must draw our attention to renewable energy sources which are the most suitable in the future. This paper presents a study about designing and simulation of a small wind-hydro power plant whi...
Article
Full-text available
This paper deals with DC - AC static converter systems, of very high voltages and currents, used for electricity power transmission. It has been analyzed three types of converters: with forced commutation, with commutation from load and the solution proposed by the authors. There are shown the advantages in hybrid switching converters, which in ess...
Article
Full-text available
This paper deals with DC – AC static converter systems, of very high voltages and currents, used for electricity power transmission. It has been analyzed three types of converters: with forced commutation, with commutation from load and the solution proposed by the authors. There are shown the advantages in hybrid switching converters, which in ess...
Article
Full-text available
DC voltage circuit breakers, initially intended for protecting and disconnecting the rectifiers (AC/DC converters), have a wide usinge in high voltage systems. This paper presents the results of turn-off LC circuit simulation with EMTPWorks software, which is connected in parallel with the main contacts of a circuit breaker. The semiconductor devic...

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Project (1)
Project
Investigation on the Protection and Risks associated with Critical Energy Infrastructure in the context of Climate Change, Man-made and Natural Threats and Disasters.