scholarly journals Calibration and Laboratory Testing of Computer Measuring System 8AE-PD Dedicated for Analysis of Acoustic Emission Signals Generated by Partial Discharges Within Oil Power Transformers

2017 ◽  
Vol 42 (2) ◽  
pp. 297-311 ◽  
Author(s):  
Franciszek Witos ◽  
Grzegorz Szerszeń ◽  
Zbigniew Opilski ◽  
Maciej Setkiewicz ◽  
Aneta Olszewska ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Steel Plate ◽  
Partial Discharges ◽  
Measuring System ◽  
Power Transformers ◽  
General Description ◽  
Emission Method ◽  
Peak Voltage ◽  
Limit Values ◽  
Ae Signals

Abstract In the paper, there are presented a general description of the constructed measuring system 8AE-PD, the results of calibration of this system by the Hsu-Nielsen method as well as the testing of the measuring system during recording signals generated by Hsu-Nielsen sources in a steel plate and a modeled partial discharge (PD) source. There is also presented the methodology of investigations by the calibrated acoustic emission method. The results of analyses of PD signals coming from the modeled sources are given. In particular, there are described the properties of acoustic emission (AE) signals generated by the PDs as well as the dependencies of the peak-to-peak voltage Umm, the RMS voltage Urms and the descriptors of acronyms ADP and ADC on the apparent charge Q introduced by the modeled PD source. There are determined the limit values of the apparent charge Q introduced by the modeled PD source for which the recorded signal is identified as originating from the PDS.

ACOUSTIC EMISSION TESTING OF POWER TRANSFORMERS INSULATION

2020 ◽  
pp. 40-44
Author(s):  
V. V. Bardakov ◽  
S. V. Elizarov ◽  
V. A. Barat ◽  
V. G. Kharebov ◽  
K. A. Medvedev
Keyword(s):  
Acoustic Emission ◽  
High Sensitivity ◽  
Partial Discharges ◽  
Power Transformers ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Emission Data ◽  
Emission Testing ◽  
Insulation Defect ◽  
Acoustic Emission Testing

Testing results of power transformers insulation for the presence of insulation defects, accompanied by the partial discharges occurrence, by means of the acoustic emission method are presented in this article. In particular, the testing of two power transformers with different lifetime was carried out. One transformer was defect-free and one with a willing insulation defect. Based on the testing results, the features of acoustic emission data for power transformers in the presence of partial discharges are found. High sensitivity of acoustic emission method for acoustic wave registration from partial discharges is shown in the article. A method for filtering of noise hits and extraction of hits from partial discharges is proposed. This method is based on excretion of acoustic emission hits from partial discharges out of total number of hits by means of periodicity of their registration, which is synchronized with power supply frequency on the first step. On the next step based on acoustic emission parameters of hits excretion on the previous step, filtration was carried out. The location of the insulation defect which led to the appearance of partial discharges was determined based on the volume location algorithm, by means of acoustic emission method. The insulation defect was confirmed by verification.

scholarly journals Application of Acoustic Emission and Thermal Imaging to Test Oil Power Transformers

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5955
Author(s):  
Franciszek Witos ◽  
Aneta Olszewska ◽  
Zbigniew Opilski ◽  
Agnieszka Lisowska-Lis ◽  
Grzegorz Szerszeń
Keyword(s):  
Acoustic Emission ◽  
Thermal Imaging ◽  
Research Method ◽  
Power Transformer ◽  
Partial Discharges ◽  
Power Transformers ◽  
Imaging Studies ◽  
Ir Radiation ◽  
Side Walls ◽  
Ae Signals

In this paper, the research methodology and the results of the analysis carried out using the acoustic emission (AE) and thermal imaging for a selected oil power transformer are presented. The basis for the research, by means of the AE method, was the author’s patented research method. The AE descriptor maps on the side walls of the tested transformer along with the location of areas with increased AE activity and an analysis of the properties of AE signals recorded at the measurement points located in these areas have been performed. The results showed no partial discharges that could threaten further operation of the tested transformer as well as three areas where increased magnetoacoustic emission occurred. Thermal imaging studies were carried out in the 7.5 μm < λ < 13 μm band. Three areas were located on the calculated thermograms: the entire upper surface of the transformer tank and two areas on the side walls of the tested transformer in which increased IR radiation occurred. The results of the analysis of the research results for the two methods correspond with each other, having a common part, and complement each other giving a broader description of studied phenomena.

A strategy to locate partial discharges in power transformers using acoustic emission

2007 ◽  
Vol 1 (05) ◽  
pp. 596-600 ◽  
Author(s):  
Giscard Franceire Cintra Veloso ◽  
◽  
Luiz Eduardo Borges da Silva ◽  
Germano Lambert-Torres
Keyword(s):  
Acoustic Emission ◽  
Partial Discharges ◽  
Power Transformers

scholarly journals Separation of AE signals for detecting solidification cracking of Al–7 mass%Si alloy by using acoustic emission method

2010 ◽  
Vol 60 (10) ◽  
pp. 492-498 ◽  
Author(s):  
Itaru Endo ◽  
Hiroyuki Chiba ◽  
Toru Ueki ◽  
Takanari Toriyama ◽  
Makoto Yoshida
Keyword(s):  
Acoustic Emission ◽  
Solidification Cracking ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Ae Signals

scholarly journals Proportional monitoring of the acoustic emission in crypto-conditions

2011 ◽  
Vol 59 (5) ◽  
pp. 31-38 ◽  
Author(s):  
Petr Dostál ◽  
Michal Černý ◽  
Jaroslav Lev ◽  
David Varner
Keyword(s):  
Acoustic Emission ◽  
Aluminum Alloys ◽  
Real Time ◽  
Fatigue Cracks ◽  
Current Status ◽  
Fatigue Properties ◽  
Material Degradation ◽  
Emission Method ◽  
Important Benefit ◽  
Ae Signals

The work is aimed at studying corrosion and fatigue properties of aluminum alloys by means of acoustic emission (AE). During material degradation are acoustic events scanned and evaluated. The main objective of the article is a description of behavior of aluminum alloys degraded in specific conditions and critical degradation stages determination. The first part of the article describes controlled degradation of the material in the crypto–conditions. The acoustic emission method is used for process analyzing. This part contains the AE signals assessment and comparing aluminium alloy to steel. Then the specimens are loaded on high-cyclic loading apparatus for fatigue life monitoring. Also, the synergy of fatigue and corrosion processes is taken into account.The aim is the description of fatigue properties for aluminum alloys that have already been corrosion-degraded. Attention is also focused on the structure of fatigue cracks. The main part of the article is aimed at corrosion degradation of aluminium alloys researched in real time by means of AE. The most important benefit of AE detection/recording is that it provides information about the process in real time. Using this measurement system is possible to observe the current status of the machines/devices and to prevent serious accidents.

scholarly journals Comparative analysis of the strength of restoration polymers of light polymerization for dental restoration using the acoustic emission method: part one

2021 ◽  
Vol 107 (3) ◽  
pp. 26-32
Author(s):  
V. Kukhta ◽  
◽  
V. Makeev ◽  
O. Kyrmanov ◽  
V. Skalsky ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Comparative Analysis ◽  
High Energy ◽  
Dental Restoration ◽  
Acoustic Emission Method ◽  
Local Loading ◽  
Emission Method ◽  
Composite Failure ◽  
Initial Stage ◽  
Ae Signals

Purpose. Comparative analysis of the strength of hybrid restoration composites of light polymerization during their local loading using the phenomenon of acoustic emission. The following restoration composites were studied: Latelux, Tetric N-Ceram, Charisma Classic. Results. It was determined that the nature of the destruction of all composites is the same: elastic-plastic at the initial stage of the load with a transition to brittle as its further growth. Three types of composite failure are observed: correct, incorrect and mixed. The first predominated during fracture under the action of local loading of the Latelux composite, for Tetric N-Ceram and Charisma Classic materials a mixed type of fracture is characteristic. Conclusions. Analysis of the parameters of the AE signals showed that the signals had the highest amplitude and energy when the Tetric N-Ceram composite was destroyed, and the lowest – Latelux. All dental composites are dominated by high-energy ductile-brittle and brittle fracture, which indicates the spread of micro- and macrocracks of various sizes in materials. Key words: polymer composites, strength, acoustic emission method.

Monitoring of the High-Technology Nailing of CFRTP Material under Ultrasonic Vibration by Acoustic Emission Method

2020 ◽  
Vol 1009 ◽  
pp. 25-30
Author(s):  
Yoshiaki Akematsu ◽  
Hiromitsu Gotho ◽  
Takayuki Tani ◽  
Hideaki Murayama ◽  
Tsuyoshi Matsuo ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Ultrasonic Vibration ◽  
Energy Parameter ◽  
High Technology ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Thermoplastic Material ◽  
Signal Characteristics ◽  
Ae Signal ◽  
Ae Signals

In this study, the potential to monitor the high-technology nailing of carbon fiber reinforced thermoplastic material (CFRTP) under ultrasonic vibration was investigated by acoustic emission (AE) method. AE signals were detected by a piezoelectric AE sensor during high-technology nailing under ultrasonic vibration. This paper describes some experimental results on AE signal characteristics and observation of the high-technology nailing. In order to investigate the effects of machining condition, we focused on RMS voltage, which is dependent on the energy parameter of the AE signal. It was found that the AE method is a useful method of monitoring high-technology nailing.

scholarly journals Development of Acoustic Emission Sensor Optimized for Partial Discharge Monitoring in Power Transformers

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1865 ◽  
Author(s):  
Sikorski
Keyword(s):  
Acoustic Emission ◽  
Partial Discharge ◽  
Low Noise ◽  
Partial Discharges ◽  
Power Transformers ◽  
Laboratory Research ◽  
Fully Differential ◽  
Peak Sensitivity ◽  
Optimal Material ◽  
Discharge Detection

The acoustic emission (AE) technique is one of the unconventional methods of partial discharges (PD) detection. It plays a particularly important role in oil-filled power transformers diagnostics because it enables the detection and online monitoring of PDs as well as localization of their sources. The performance of this technique highly depends on measurement system configuration but mostly on the type of applied AE sensor. The paper presents, in detail, the design and manufacturing stages of an ultrasensitive AE sensor optimized for partial discharge detection in power transformers. The design assumptions were formulated based on extensive laboratory research, which allowed for the identification of dominant acoustic frequencies emitted by partial discharges in oil–paper insulation. The Krimholtz–Leedom–Matthaei (KLM) model was used to iteratively find optimal material and geometric properties of the main structures of the prototype AE sensor. It has two sensing elements with opposite polarization direction and different heights. The fully differential design allowed to obtain the desired properties of the transducer, i.e., a two-resonant (68 kHz and 90 kHz) and wide (30‒100 kHz) frequency response curve, high peak sensitivity (−61.1 dB ref. V/µbar), and low noise. The laboratory tests confirmed that the prototype transducer is characterized by ultrahigh sensitivity of partial discharge detection. Compared to commonly used commercial AE sensors, the average amplitude of PD pulses registered with the prototype sensor was a minimum of 5.2 dB higher, and a maximum of 19.8 dB higher.

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