Towards the text compression based feature extraction in high impedance fault detection

High impedance faults of medium voltage overhead lines with covered conductors can be identified by the presence of partial discharges. Despite it is a subject of research for more than 60 years, online partial discharges detection is always a challenge, especially in environment with heavy background noise. In this paper, a new approach for partial discharge pattern recognition is presented. All results were obtained on data, acquired from real 22 kV medium voltage overhead power line with covered conductors. The proposed method is based on a text compression algorithm and it serves as a signal similarity estimation, applied for the first time on partial discharge pattern. Its relevancy is examined by three different variations of classification model. The improvement gained on an already deployed model proves its quality.Web of Science1211art. no. 214

An examination of thermal features' relevance in the task of battery-fault detection

Uninterruptible power supplies (UPS), represented by lead-acid batteries, play an important role in various kinds of industries. They protect industrial technologies from being damaged by dangerous interruptions of an electric power supply. Advanced UPS monitoring performed by a complex battery management system (BMS) prevents the UPS from sustaining more serious damage due to its timely and accurate battery-fault detection based on voltage metering. This technique is very advanced and precise but also very expensive on a long-term basis. This article describes an experiment applying infrared thermographic measurements during a long term monitoring and fault detection in UPS. The assumption that the battery overheat implies its damaged state is the leading factor of our experiments. They are based on real measured data on various UPS battery sets and several statistical examinations confirming the high relevancy of the thermal features with mostly over 90% detection accuracy. Such a model can be used as a supplement for lead-acid battery based UPS monitoring to ensure their higher reliability under significantly lower maintenance costs.Web of Science82art. no. 18

Electrical Part of Power Stations

Import 03/08/2012Tato bakalářská práce popisuje problematiku elektráren, zejména jejich elektrické části. Jsou zde popsány základní principy funkce různých druhů elektráren, možnosti provozu, jednotlivá technologická zařízení a jejich vliv na chod a celkovou účinnost elektrárny. Podrobně jsou popsány jednotlivé prvky elektrické části elektráren, možné způsoby jejich provozu a zapojení. Jsou zde také popsány možnosti realizace a zapojení ochran jednotlivých prvků elektrické části a také možné způsoby pokrytí vlastní spotřeby elektrárny. Poslední část práce popisuje některé ze současných trendů.This thesis describes the problem of power stations, especially their electrical parts. It describes the basic operational principles of different types of power stations, the possibility of operation, individual technological devices and their effect on the operation and overall efficiency of power stations. There are described in detail the individual elements of the electric part, possible ways of their operation and connection. There are also discussed the possibilities of protection individual elements of electrical parts and possible ways of covering power station own consumption. The last part describes some of the current trends.410 - Katedra elektroenergetikyvelmi dobř

Photovoltaic Panels Power Supply for the Crossing Safety Devices

Import 05/08/2014Tato práce se zabývá problematikou napájení přejezdových zabezpečovacích zařízení fotovoltaickými panely. Za tímto účelem byla vypočtena spotřeba nejběžnějších přejezdových zabezpečovacích zařízení na našem území a vyhodnoceny možnosti jejich napájení. Rovněž byla zpracována data z dlouhodobého měření na zkušebním přejezdu, napájeném fotovoltaickými panely. Na základě tohoto měření byl navržen zdroj pro přejezdové zabezpečovací zařízení typu JLC z produkce firmy AŽD Praha.This thesis deals with the problems of power supplies for the crossing safety devices, provided by photovoltaic panels. For this purpose, the consumption of the most common crossing safety devices in the Czech Republic was calculated. The data from long-term measurement of the test crossing, fed by photovoltaic panels, was also processed. Based on this measurement, a power source for crossing safety device type JLC (production of AŽD Praha company) was designed.410 - Katedra elektroenergetikyvýborn

Individual Professional Practice in the Company

Tato práce je bakalářskou prací pro obor Projektování elektrických systémů a technologií na Vysoké škole Báňské – Technické univerzitě Ostrava na Fakultě elektrotechniky a informatiky. Tato bakalářská práce pojednává o absolvování individuální praxe ve společnosti Schrack Technik spol. s r. o. a o teorii spojenou s prací, kterou jsem absolvoval v této společnosti. Po úvodu následuje popis jednotlivých projektů. Konkrétně se práce zabývá podrobně třemi projekty a to: výukovým panelem rozhraní DALI, šablonami elektroměrových rozváděčů a návrhem kuchyňské elektroinstalace. Dále je v bakalářské práci obsažena kapitola „Ostatní projekty“. V této kapitole lze nalézt projekty, který je vhodné zmínit a v krátkosti představit.This work is a bachelor thesis for the study program “Design of Electrical Systems and Technologies” at the VSB – Technical University of Ostrava, Faculty of Electrical Engineering and Computer science. This bachelor thesis deals with the completion of an individual internship in the company Schrack Technik lnc. and the theory associated with my work in this company. The introduction is followed by a description of each project. Specifically, the thesis deals in detail with three projects, namely: the DALI interface tutorial panel, the electric meter templates and the kitchen wiring design. Furthermore, the thesis contains a chapter "Other projects". In this chapter can be found projects that should be mentioned and briefly introduced.420 - Katedra elektrotechnikyvýborn

Fast algorithm for contactless partial discharge detection on remote gateway device

Detection of the high impedance fault caused by vegetation is one of the biggest challenges brought by the usage of covered conductors in medium voltage overhead power lines. One of the accompanying events of long-term contact of vegetation with the XLPE insulation is partial discharge which damages the insulation. Current systems for the detection of partial discharge have two major problems: the price and difficult installation. In this paper, an approach for the detection of the partial discharge from the data collected by the antenna is described. This approach is focused on the small computational demand and low false positive rate. Thanks to the small computational requirements, it can be run on the remote gateway devices which are collecting the data from the antenna. It is composed of four steps: outlier detection, outlier clustering, feature extraction, and classification. It is shown that this approach greatly improves the detection rate and lowers false positives compared to the previous algorithm used for partial discharge detection based on the data from an antenna, making it fit to use in the production environment.Web of Science3732130212

Analysis of the state of the industrial area of the former agglomeration in Ostrava-Vítkovice

Předložená diplomová práce poskytuje analýzu průmyslového brownfieldu v Ostravě-Vítkovicích, v areálu původně využívaného pro těžký průmysl (výrobu aglomerátu). Kromě rozboru stavu území a jeho limitů, je provedena analýza s ohledem na jeho ekonomický potenciál. V úvodu jsou po stručné rekapitulaci teoretických východisek shrnuty poznatky o řešeném území, a to jak z hlediska historického vývoje, místopisu, dostupnosti inženýrských sítí a dopravní infrastruktury, tak i ve věci územně-plánovací dokumentace. V praktické části je provedena analýza srovnatelných zón, a dále SWOT analýza skrze možnost zachování významné dominanty v území a také stávající situace zkoumané zóny. Dále je proveden návrh využití předmětného území a provedeny ekonomické kalkulace související s navrhovaným řešením území.Submitted diploma thesis presents analysis of industrial brownfield in Ostrava – Vítkovice. The industrial area was used for heavy industry – agglomerate production. The thesis is focused on analysis of current area condition, its limits, and economic potential. The introduction briefly summarize theoretical outcomes and information about area. It is based on historical evolution, topography, availability of utilities and transport infrastructure, and land-use planning documentation. The practical part contains of comparable areas analysis, SWOT analysis to keep important dominant element in the area and evaluate current area conditions. Furthermore, the proposal of the territory in question utilization is created and includes several related financial calculations and economic prediction.222 - Katedra městského inženýrstvívelmi dobř

A simple method for tree fall detection on medium voltage overhead lines with covered conductors

Covered conductors are an alternative to aluminum core steel reinforced medium voltage overhead lines in forested terrains. The covered conductors are highly reliable due to the XLPE insulation system, which prevents the short-circuit current in case of contact of phases with the surrounding vegetation. However, the disadvantage of the covered conductor operation is the problematic detection of high impedance faults. Such type of faults is usually caused by the surrounding vegetation. The covered conductor may get ruptured or damaged due to the destructive degradation of the insulation system during the high impedance fault. This article contains a description and results of a new fault detection system for medium voltage overhead lines with covered conductors. The method of insulation fault identification is based on partial discharge activity detection. Our aim is to develop cheap and reliable online detector, which could be installed in large quantities for optimal high impedance fault detection and localization. Common partial discharges detectors are too expansive for this purpose.Web of Science3631417141

Usage of antenna for detection of tree falls on overhead lines with covered conductors

The direct contact of a tree or a branch of tree with Covered Conductors (CC) overhead lines causes Partial Discharges (PD) inside the insulation. The presence of PD degrades the insulation systems and eventually destroys insulation, which may lead to power delivery interruption. The detection and diagnosis of PD is an important tool to address the problem of tree caused faults in forested terrains. The PD occurs in the impulse component of the signal, which is usually measured by Rogowski coil (current signal) or single layer inductors (voltage signal). In this paper, we introduce a possibility to detect the tree caused faults with the usage of whip antenna. The advantage of the antenna is a very low price and the possibility to install antenna under voltage. The disadvantages are sensitivity to ferromagnetic materials and impossibility to distinguish affected phase. The measurements were carried out in the real environment in forested terrain in Jeseniky Mountains. The real environment is different from a laboratory conditions due to heavy noise (e.g. corona, radio emissions). This paper provides an examination of the background noise from the antenna signal. The experimental results indicate that the antenna may be successfully used instead of the current approach

Paramutation of tobacco transgenes by small RNA-mediated transcriptional gene silencing

It has been well established that trans-acting small RNAs guide promoter methylation leading to its inactivation and gene silencing at the transcriptional level (TGS). Here we addressed the question of the influence of the locus structure and epigenetic modifications of the target locus on its susceptibility for being paramutated by trans-acting small RNA molecules. Silencing was induced by crossing a 35S promoter silencer locus 271 with two different 35S-driven transgene loci, locus 2 containing a highly expressed single copy gene and locus 1 containing an inverted posttranscriptionally silenced (PTGS) repeat of this gene. Three generations of exposure to RNA signals from the 271 locus were required to complete silencing and methylation of the 35S promoter within locus 2. Segregating methylated locus 2 epialleles were obtained only from the third generation of hybrids, and this methylation was not correlated with silencing. Strikingly, only one generation was required for the PTGS locus 1 to acquire complete TGS and 35S promoter methylation. In this case, paramutated locus 1 epialleles bearing methylated and inactive 35S promoters segregated already from the first generation of hybrids. The results support the hypothesis that PTGS loci containing a palindrome structure and methylation in the coding region are more sensitive to paramutation by small RNAs and exhibit a strong tendency to formation of meiotically transmissible TGS epialleles. These features contrast with a non-methylated single copy transgenic locus that required several generations of contact with RNA silencing molecules to become imprinted in a stable epiallele