The issue of an effective assessment the technical condition mechanical structure power transformer core and windings originated research work discussed in this paper. This publication presents results which indicate possibility developing a new noninvasive diagnostic method active part. developed is based on time-frequency analysis vibrations measured monitored appliance. registration performed during switching into idle operation. paper characterizes object under study, measuring system...

The genesis of the research work presented in this paper constitutes issue effective and efficient recognition single-source one-time partial discharge forms that can occur insulation systems power transformers. presents results referring to use single-direction artificial neural networks for recognizing basic paper-oil impaired by aging processes. show effectiveness depending on descriptor analysis acoustic emission signal analysis. detailed cognitive aim was selection input parameters an...

The subject matter of this paper refers to the improvement acoustic emission (AE) method when used for detection, measurement and location partial discharges (PDs) in oil insulation systems power appliances. In particular, presents basic assumptions describe individual elements an expert diagnostic system, which uses asset state measured transformer insulation, performed during their normal work industrial conditions. system will consist four modules, i.e. measuring processing-analyzing...

This study presents the case of a substation in-service power transformer referred to on-site partial discharge (PD) detection and evaluation methods. An original methodology for simultaneous application three methods is proposed: electrical, acoustic ultra-high frequency. Transformer powered by grid no external generator required according proposed methodology. Furthermore, several possibilities applying these concurrent measurements benefits such solution in terms result interpretation,...

This paper presents an original data acquisition and transmission system designed optimized for on-line temperature monitoring systems in electric power transformers – is called SPOTEL. The main purpose of this work to evaluate a cost effective that based on open source components modular hardware layout, supporting the highest reliability safety security requirements, allowing it applications under demanding industrial conditions. A detailed description proposed design presented, including...

Aiming at solving the problem of dual resource constrained flexible job shop scheduling (DRCFJSP) with differences in operating time between operators, an artificial intelligence (AI)-based DRCFJSP optimization model is developed this paper. This introduces loading and unloading operation workers before after process. Subsequently, quantum genetic algorithm (QGA) used as carrier; process coded through coding; niche technology to initialize population, adaptive rotation angle, mutation...

Abstract An acoustic emission method (AE) is widespread and often applied for partial discharge (PD) diagnostics, mainly due to its ease of application as well noninvasiveness relatively high sensitivity. This paper presents comparative analysis AE signals measurement results archived under laboratory conditions on-site actual generated by inside PDs in electrical power transformer during normal service. Three different PD model sources are research: point point, multipoint plate surface...

The subject presented in this paper refers to measurements and assessment of the corrected sound pressure level values (noise) occurring around a medium-power transformer.The presents noise accompanying operation power object before after its modernization, which consisted repeated core pressing replacement cooling system.The main aim research work was influence repair on emitted into environment.

Abstract This paper provides an example of the application acoustic emission (AE) method for diagnosis technical conditions a three-phase on-load tap-changer (OLTC) GIII type. The measurements were performed amount 10 items OLTCs, installed in power transformers with capacity 250 MVA. study was conducted two different OLTC operating during tapping process: under load and free running conditions. analysis measurement results made both time domain time-frequency domain. description AE signals...

This paper presents the preliminary results of performed experiment, based on common phenomenon partial discharges.A simple GeigerMuller counter (DP-66M) was used for measurement a dose ionizing radiation, which is accompanied by discharges.Values from radiation intensity dependent could be controlled individually: distance between measurer and source, as well voltage generating discharges.The obtained indicate that in examined phenomenon, signicant X-ray present.According to...

The paper presents research results referring to the development of a non-invasive method assessment power transformer core technical condition based on analysis mechanical vibrations registered.It characterizes object under study, measuring system used and developed methodology pressing degree using vibroacoustic method.The original time-frequency signals presented in were obtained during switching real 800 kVA dry type laboratory conditions.The registered was carried out for three states...

The paper deals with mathematical modeling of acoustic emission signals which are generated in on load tap changers.In power engineering area method is commonly used for diagnosis purposes.Authors their research works apply it detection defects occurring changers, important elements transformers.The based measurements performed by use wideband piezoelectric transducers that mounted transformer tank surface.The registered signal then analyzed the time, frequency, and timefrequency domains or...

An important part of electric power transformer is the on load tap changer which enables for voltage regulation in network.Due to high level failure frequency these devices it necessary look new diagnostic methods enable theirs technical state estimation under normal operating condition.Presently at Electric Power Institute Opole University Technology there are works progress aspiring determine application possibility acoustic emission method diagnosis.Results scientically-research aiming...

A proposal of the dynamic thermal rating (DTR) applied and optimized for low-loaded power transformers equipped with on-line hot-spot (HS) measuring systems is presented in paper. The proposed method concerns particular population mid-voltage (MV) to high-voltage (HV) transformers, a case study over 1500 units low average load analyzed. Three representative real-life working are selected evaluation verification. Temperatures used analysis were measured continuously within two years 1 h...

The paper presents the results of vibroacoustic investigations and measurements acoustic pressure level (noise) a transformer model.The were taken at full load in two operation conditions: producer packeted core unpacketed core.Unpacketing consisted loosing screws pressing particular plates.Mechanical vibrations registered was measured.The analysis are presented form frequency spectra under study shown by determining corrected values analysis.

Abstract This article presents the results of research connected with development and industrial use vibroacoustic methods for evaluation technical condition active part transformers. The analysis vibrations generated by high power transformer in which a defect was found on basis tests oil carried out using chromatography tests. In order to confirm damage this transformer, measurements were performed three states its operation. measurement classical method included registration at idle speed...

In the article results of measurements and analyses optical signals emitted by electrical surface partial discharges occurring on bushing post insulators, recorded with UV camera during tests under laboratory conditions are presented.The carried out research was to determine eect distance between insulator's electrodes voltage value number discharges.

The paper reports the results of a comparative assessment concerned with effectiveness identifying basic forms partial discharges (PD) measured by acoustic emission technique (AE), carried out application selected machine learning methods. As part re-search, identification involved AE signals registered in laboratory conditions for eight classes PDs that occur paper-oil insulation systems high-voltage power equipment. On basis emitted and frequency descriptor took form signal density...

The subject matter of this paper refers to the assessment technical condition a power transformer core and windings based on vibroacoustic measurements taken during transient operation state appliance diagnosed -at unit switch on.The presents preliminary results research work carried out, which aims at elaborating new diagnostic method degree winding pressing using so-called modified method.The characterizes measurement path selected analyses signal registered.The original presented in were...

The paper presents research results referring to the development of a non-invasive method assessment power transformer core technical condition based on analysis registered mechanical vibrations. It characterizes unit under study, measuring system used and developed methodology pressing degree using vibroacoustic method. original time-frequency signals presented in were obtained during switching real 630 kVA dry type laboratory conditions. was carried out for three states its operation:...

In this investigation, dissimilar material AA6061-T6 and Cu B370 were joined by friction stir welding (FSW). This paper presents a feasibility study of FSW to join Al-alloy Cu-alloy. The experiment was conducted using general full factorial design varying the tool rotation speed, weld probe offset, keeping plunge depth constant. research work, statistical model established build connection between process variables outcomes—yield strength (YS), ultimate tensile (UTS) % elongation (% E)....

The article presents the results concerning use of clustering methods to identify signals acoustic emission (AE) generated by partial discharge (PD) in oil-paper insulation.The conducted testing featured qualitative analysis following methods: single linkage, complete average centroid linkage and Ward linkage.The purpose was search tested series AE signal measurements, deriving from three various PD forms, for elements grouping (clusters), which are most similar one another maximally...