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Continuous development of electrical power systems has resulted in very complex relay protection system with associated numerical protection algorithms. Reliability, selectivity and speed are the basic design requirements for the development of new algorithms. Ideally the amplitude estimation algorithms should determinate the amplitude as fast as possible, theoretically with just one sampled value...
The aim of this paper is to describe diagnostic tests which measure capacitance and factor of dielectric losses of transformers' insulation system. Transformers insulation system consists of paper insulation and insulating oil. The factor of dielectric losses is the ratio of active and reactive components of current and as such reflects changes of both currents. It is less dependent on dimensions...
Wind speed plays a vital role for wind energy calculation of a certain location. Appearances and variations of monthly wind speed data in the Republic of Macedonia were analyzed in this paper. Five measuring stations, placed across are the base source for the measured data. Primarily, the data are summarized and represented graphically by time series plots for seasonal analysis. We have compared wind...
In this paper, a compressed sensing approach for the reconstruction of 2D sparse signals with missing samples is presented. The statistical behavior of transform coefficients in the case of randomly undersampled signals is exploited as the basis of a simple algorithm for the signal support detection. With the detected signal support various reconstruction methods can be applied in the signal recovery:...
We have designed a method for programmable NMR (N-modular redundancy) voters that relies on a binary matrix and enables easy scaling of the design regarding the number of voter inputs N. Thus, an automated construction of NMR systems is possible, given the basic module and arbitrary redundancy N. In this paper we present the mathematical aspects of the method, i.e., we analyze the properties of the...
This paper demonstrates a wideband complementary LC-VCO using capacitive-source-degeneration (CSD) technique for WiFi and LTE applications. A cross-coupling pair is required to generate suitable-gm but the parasitic capacitance of the pair leads to a reduction of capacitance ratio of varactors and thus, tuning range of a VCO. Properly designing source-degeneration capacitance can relieve this reduction...
Prioritization of voice packets is useful to cope with packet losses in VoIP services by providing a mechanism to priority-enabled networks for dropping first the least important content, in order to reconstruct the best quality signal for user perception. A contribution to an efficient solution for voice packet prioritization is proposed in this paper, using an Arduino platform to implement a dynamic...
The popularity of Blockchain technology and the huge extent of its application, results with much ongoing research in different practical and scientific areas. Although still new and in experimenting phase, the Blockchain is being seen as a revolutionary solution, addressing modern technology concerns like decentralization, trust, identity, data ownership and data-driven decisions. At the same time,...
In this study a numerical cryptanalysis of a random number generator (RNG) which is built on a continuous-time chaotic oscillator is introduced. In order to scrutinize the security weaknesses of the RNG, a master-slave synchronization approach is presented as the basis of an attack scheme. By proposing this attack scheme, it is aimed to verify whether there exist any possibility to divulge the hidden...
The University of Applied Sciences Technikum Wien offers various courses dedicated to electronic engineering and embedded systems hardware & software design. These courses are embedded in various degree programs such as full-time, part-time, and distance learning. The attendees of these courses train their skills and expertise on the basis of labor exercises, assignments, and tasks. Especially...
Since the first Phasor Measurement Units in Slovenian electricity transmission system operator's (ELES) grid have been put in operation in 2005, the number of installed units has grown considerably. In addition, in recent years, connections have been established with grid operators from Switzerland, Denmark, Italy, Germany, Montenegro and Austria with the purpose of exchanging available measurement...
In the last ten years PMUs (Phasor Measurement Units) play a more and more important role for the on-line monitoring and analysis of the state of the electrical systems. The reasons for this development are dynamic loading of transmission systems, demand on flexibility of generation, high penetration of renewable generation and decentralized load and generation centers. PMUs today allow measuring...
An architecture for hardware realization of a system for sparse signal reconstruction is presented in the paper. The threshold based reconstruction method is considered. Noise, appearing in the signal as consequence of the missing signal samples, is used to derive the threshold. The threshold is then used in order to separate signal and non-signal components, and it is dependent on the number of missing...
In this paper, a maximum power point tracking (MPPT) architecture for micro-scale photovoltaic (PV) energy harvesting systems is presented. A switching DC-DC boost converter is used to provide the required voltage for the circuits of the ultra-low-power application. The MPPT tracks different illumination intensities through changing the input impedance of the boost converter. The proposed technique...
This paper deals with the optimal fault-tolerant operation of a 5-phase permanent magnet (PM) brushless DC (BLDC) drive. In particular, this paper (Part I) proposes the modelization used to optimize the motor current supply to obtain the maximum power in healthy conditions and its analytical solution is presented. In the companion paper (Part II) the drive is considered both in healthy and faulty...
The growth of electrification transportation systems is an opportunity for delving into new feasible solutions for more reliable and fault tolerant arrangements. So far, many investigations distant from the market have been carried out. Most of the works are looking at new control strategies adding extra components increasing manufacturing efforts and costs. Considering a nine phase synchronous multi-three...
This article describes functionalities and specific features of the “DICOM Network” informational system that provides possibility to collect, process, archive, distribute and visualize data in DICOM format. Presented technical and architecture details and proved the benefits for end users to use the system for secure access to DICOM investigations. DICOM format and protocols described in the article...
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