Online assessment of winding deformation based on optimised excitation
25 Oct 2010-pp 84-89
TL;DR: On line assessment of winding deformation in a power transformer can be performed via a bushing tap excitation with optimized high frequency excitation through a benchmark layer winding to validate the suitability of the technique.
Abstract: On line assessment of winding deformation in a power transformer can be performed via a bushing tap excitation with optimized high frequency excitation. A benchmark layer winding is used to validate the use of the specific high frequency excitation. Axial displacement, compression and buckling of the winding are simulated and the changes identified. Measurements are performed on a voltage transformer to verify the suitability of the technique. The procedure will result in a considerably shorter time for measurement.
Citations
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TL;DR: In this article, the authors present the current status and future trends in the application of the frequency response analysis (FRA) technique with the transformer in service (online) through bibliographic review and analysis.
Abstract: This paper presents the current status and future trends in the application of the frequency-response analysis (FRA) technique with the transformer in service (online) through bibliographic review and analysis. As a result, three basic stages of the online FRA test have been identified and defined: injection and excitation signal measurement; recording, filtering and processing of measured signals; and curve analysis and interpretation. This work presents an overview of the online FRA technique, useful for subsequent research in this area.
114 citations
Cites methods from "Online assessment of winding deform..."
...The second reference presents an online assessment of winding deformation by using optimized multi-sine excitation compared to a chirp signal [42]....
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01 Sep 2016
TL;DR: In this article, the authors proposed a technique for in-service monitoring of power transformer winding deformation, which uses a broad frequency sine wave voltage excitation signal and high frequency Current Transformers (CT) in conjunction with the bushings test taps.
Abstract: Frequency response analysis (FRA) is a technique used to diagnose the mechanical integrity of a transformer winding; such diagnostic tools can be of enormous value since power transformers are a critical asset within any electrical network. To minimize the probability of an unexpected outage, or prevent a catastrophic failure, maintenance and monitoring of power transformers is essential for utilities. Over the past couple of decades, FRA has been utilized as an off-line diagnosis method. However, with the recent development in smart grid systems, there is now a growing interest in the development of on-line FRA techniques. This paper proposes a technique for in-service monitoring of power transformer winding deformation, which uses a broad frequency sine wave voltage excitation signal and high frequency Current Transformers (CT) in conjunction with the bushings test taps. Experiments using this system were conducted and then validated on a single-phase 22kV/110V voltage transformer.
14 citations
Cites methods from "Online assessment of winding deform..."
...Methodology Bushing tap injection techniques utilizing voltage sensors and current probes were considered by Setayeshmehr [10] and other researchers [11]-[13]....
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01 May 2017
TL;DR: In this article, a growing interest in the development of on-line monitoring techniques for smart grid systems is discussed, which is to reduce the maintenance costs as well as minimize the probability of unexpected outages, or potentially to prevent catastrophic failures in the electrical network.
Abstract: With the recent development in smart grid systems, there is now a growing interest in the development of on-line monitoring techniques. This is to reduce the maintenance costs as well as minimizing the probability of unexpected outages, or potentially to prevent catastrophic failures in the electrical network.
6 citations
01 May 2014
TL;DR: In this paper, Finite Element Method (FEM) and Sweep Frequency Response Analysis (SFRA) are used to model deformation on a benchmark winding and obtain corresponding signatures, which are used as indices to distinguish type and location of deformation.
Abstract: Winding deformation in power transformers affects its mechanical integrity. Diagnosis of winding deformation is a necessary step towards preventing its permanent failure. Sweep Frequency Response Analysis (SFRA) is widely used to analyze the nature and extent of deformation. However, the location of deformation needs the signature from the deformed transformer at various locations, which is practically not feasible. In this paper, Finite Element Method (FEM) and SFRA are used to model deformations on a benchmark winding and obtain corresponding signatures. Different parameters derived from SFRA are used as indices to distinguish type and location of deformations.
4 citations
Cites methods from "Online assessment of winding deform..."
...An improved method is proposed in [8] that gives faster response by the use of optimized multi-sine signal....
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11 Jun 2019
TL;DR: It is revealed that the winding inter-disk and inter-turn faults lead to FRA anti-resonance frequency shift and response magnitude alteration in online FRA.
Abstract: Transformers are considered as the key components in power system network as they are employed in generation, transmission and distribution sectors. Hence electricity providers are highly concerned about proper operation of these valuable assets and specifically normal performance of the transformer active parts. One of the most reliable techniques to monitor the active part of the transformer is the Frequency Response Analysis (FRA). Given the fact that FRA technique has been successfully utilized in offline application for transformer diagnosis; it has been recently studied to apply the FRA once the transformer is in service, called online FRA. In this study, the transformer winding inter-disk and inter-turn faults are studied along with the effect of the bushing on frequency response signature in online FRA setup. Transformer winding physical model is created, simulated and numerically analyzed. It is revealed that the winding inter-disk and inter-turn faults lead to FRA anti-resonance frequency shift and response magnitude alteration in online FRA. Emulation of transformer bushing in the form of two paralleled capacitors unveils the significant influence of this component over the low frequency band of FRA spectrum. Destructive effect of the bushing reactive impedance should be taken into consideration during online FRA test measurements.
2 citations
Cites background from "Online assessment of winding deform..."
...Active part mechanical faults can be expressed as the winding inter-disk or inter-turn shortcircuit, displacement or deformation, buckling, bending, spiraling, rupture, tilting, or the faults related to the transformer core, or the faults in diverter- or selector switch of tap-changer [6]-[11]....
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References
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16 May 2005
TL;DR: In this article, a new method of testing and analyzing winding deformation online without untanking is presented, and a comparison of Fourier transform and Wigner-Ville distribution methods of analysis is carried out.
Abstract: Transformers are required to demonstrate the ability to withstand short circuit currents. Over currents due to short circuit can cause winding deformation. A new method of testing and analyzing winding deformation online without untanking is presented in this paper. A study of alternate excitations to detect winding deformation is made. A comparison of Fourier transform and Wigner-Ville distribution methods of analysis is carried out
9 citations
"Online assessment of winding deform..." refers background in this paper
...It is previously shown that an oscillating impulse voltage or a chirp signal would be possible candidates for concurrent high frequency excitation during a short circuit test [5], [6]....
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19 Oct 2003
TL;DR: In this article, it is shown that the nearest neighbourhood rule based on a clustering approach provides a good framework for fault location. But it is not shown how to estimate the location of the fault based on the resonant frequencies of the winding current.
Abstract: It is possible to estimate the location of the fault based on a study of the resonant frequencies of the winding current. It is shown that the nearest neighbourhood rule based on a clustering approach provides a good framework for fault location. Additional signal acquisition in the form of the tank current can considerably simplify the identification of a fault to ground. Experimental investigations are performed in order to identify and locate breakdown in windings.
7 citations
"Online assessment of winding deform..." refers methods in this paper
...This is similar to the method demonstrated for identifying breakdown location in windings [9]....
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31 Oct 2008
TL;DR: In this article, the authors show that optimized multisine excitation has the potential of high sensitivity towards displacement identification, and they also show that a multispectral excitation with high sensitivity has a high sensitivity toward displacement identification.
Abstract: The mechanical strength and integrity of the transformer windings is established by short circuit test. Reactance comparison method and frequency response analysis methods are conventionally used to assess the failures. Concurrent application of various high frequency excitations has also been tested. We show that optimized multisine excitation has the potential of high sensitivity towards displacement identification.
3 citations
"Online assessment of winding deform..." refers background in this paper
...It is previously shown that an oscillating impulse voltage or a chirp signal would be possible candidates for concurrent high frequency excitation during a short circuit test [5], [6]....
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