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The problem of identifying a disturbance and transient duration in power systems at the appropriate time is crucial. The necessity of an early disturbance detection is driven by the essential aims of dispatching control and automatic emergency control systems, both local and centralized. The paper proposes a flexible algorithm for identifying a disturbance and transient duration, based on the "hinge...
Electric characteristics of Aluminum Conductor Steel Reinforced (ACSR) components, aluminum and steel conductivity values, are usually provided by the ACSR manufacturers, but not the steel core permeability. In order to explore how important the steel core permeability is, the paper deals with the impact of this characteristic on ACSR impedance per unit length. For the estimation of this impact, numerous...
Figure detection, separation and image classification are common problems occurring in various fields, especially medicine. Since image databases are usually large, manual classification would be a demanding task. In this paper, we proposed a method for automatic compound figure detection and separation, and gave a comparison between other recognition methods, such as convolutional neural networks...
This paper considers how selection techniques applied in an orthogonal frequency division multiplexing (OFDM)-based wireless local area network (WLAN) system influence on a system performance. Namely, ergodic and outage capacity of the considered system are simulated in order to determine the most adequate receiver design for certain WLAN environment.
Large computational load is one of the key issues of an electrical power system security analysis. Currently, most of the researchers are trying to find out how to reduce the computational load. The contingency analysis is one of the most promising approaches for solving the problem. In fact, there are several ways to improve the effectiveness of the contingency analysis. The first way is to reduce...
The problem of the power consumption forecast calculation is solved for all time intervals with the subsequent increase in the accuracy while the prediction intervals are decreasing. The lack of complete information on all types of node loads of the controlled power system makes it necessary to solve the problem of their determination. The composition of the nodes and methods of loads modelling are...
This paper presents a convolutional neural network clustering approach for handwritten digits recognition. Neural networks were trained individually, using the same training set and combined into clusters, depending on the training method used. These clusters formed a layered architecture, where each layer attempted to recognize the given digit, when the previous layers were not able to do so with...
The energy harvesting applications becomes omnipresent, utilizing different harvesting techniques to collect energy from ambient. Recently, the electromagnetic field energy harvesting attracted attention, with objective to provide nearly unlimited power supply, particularly for variety of the low-power electronic devices. Furthermore, the inductive assemblies have been recognized as reliable, low...
Determination of normal magnetization curve is a well known problem, solved and described in many papers. But none of the normal magnetization curve measurements were performed applying current transformer instead of voltage toroidal transformer sample. Comparing the application of current transformer versus the application of voltage transformer, several different procedures and approaches appeared...
The operating modes control of 35 kV, 6/10 kV distribution grids within the concept of Smart Grid is currently possible due to the impact on the control units available in the grid. The devices include: a transformer with on-load tap changing, energy storage systems, switching equipment, reactive power sources, distributed generators. A combined use of these control devices would allow performing...
Three-dimensional laser scanning of power equipment and facilities of electric power systems (power plants and substations) is a new high-tech activity of the 3D laboratory of the «Automated Power Systems» department of the Ural Power Engineering Institute, UrFU. Laser scanning allows providing full reproduction of topographic and geometric data of the power facility. The implementation of reverse...
Thin oxide films are dominantly used as insulating materials in a wide range of CMOS electronic devices. Continuous scaling, governed by Moores Law, dictates that the thickness of oxides materials could be as thin as a few nanometers. Consequently, a generation of oxide defects, through field-driven and thermal-driven processes, presents a serious reliability challenge. On the other hand, a controllable...
Nowadays, DC/DC converters are widely used in industrial applications and renewable energy systems. A SEPIC (single-ended primary inductance converter) DC-DC converter is capable of operating in either step-up or step-down mode and commonly used in a battery charger system. This paper presents the modeling and analyzing of the SEPIC with coupled and uncoupled inductors. In this study, the state-space...
This paper investigates applicability of the in-house solver based on the TLM method adapted to the cylindrical grid and improved with the compact wire model for the purpose of EM field characterization using a number of radially placed wire probes within cylindrical cavity resonator. Both an empty and a coaxially loaded cavity have been investigated.
Phase Locked Loop (PLL) is wide used for grid parameters estimation, as well for grid-converters synchronization. Key block at single-phase Synchronous Reference Frame PLL (SRF-PLL) structure is two-phase generator which is used for generation of two quadrature signals, which are necessary for SRF block. One of the issues that could appear during estimation of grid parameters is appearance of DC offset...
This paper solves harmonic elimination problem, and minimizes total harmonic distortion by a recently developed heuristics: moth-flame optimization method. 5th and 7th order harmonics are eliminated for a seven level cascaded multilevel inverter, and 5th, 7th, 11th and 13th order harmonics are eliminated for an eleven level cascaded multilevel inverter. Simulation results of a seven level cascaded...
This paper presents a modification of recently reported general rules for designing complex controllers. The presented approach is here applied to control stable processes including dead-time with a dominant left half-plane zero. The introduced modification enables improvements in the form of better disturbance rejection and smaller IAE (Integrated Absolute Error). The solution to design procedure...
This paper contains the analysis and description of software solution for MHEG-5 engine upgrade, compatible with the newest version of MHEG-5 specification for South African market. Since the changes are related to File System Acceleration extension, the aim of this paper is to propose implementation of the upgraded software solution in the as simple as possible way, without significant performances...
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