Location of breakdown in windings using concurrent UHF antenna and current responses
01 Sep 2008-pp 581-584
TL;DR: In this paper, the use of concurrent UHF antenna and winding currents was proposed to locate breakdown in dry-type transformers, and the work can be extended to identify partial discharge events in dry type transformers.
Abstract: Changes in resonant frequencies of a winding can identify the location of breakdown during impulse tests. This is difficult with a uniform winding. We propose the use of concurrent UHF antenna and winding currents in order to locate breakdown. The work can be extended to identify partial discharge events in dry type transformers.
References
More filters
TL;DR: In this paper, the UHF technique is applied increasingly to monitor partial discharges (PD) in power transformers and has been shown to be much more sensitive than acoustic techniques when the signal path passes through solid insulation.
Abstract: Because of the large capital value of power transformers and their critical role in the electricity network, there is an increasing need for non-intrusive diagnostic and monitoring tools to assess their internal condition. The UHF technique is being applied increasingly to monitor partial discharges (PD) in power transformers and has been shown to be much more sensitive than acoustic techniques when the signal path passes through solid insulation. Field trials were performed on five power transformers ranging in size from 18 to 1000 MVA and in voltage from 25 to 400 kV. The results of PD tests on power transformers provide sufficient evidence to justify making provision for UHF sensors on new transformers to facilitate their monitoring when required during the service lifetime.
183 citations
"Location of breakdown in windings u..." refers methods in this paper
...There has been some work on the use of UHF antenna in transformers applications as summarized in [4]....
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30 Jan 2004
TL;DR: In this article, an objective classification of faults that can occur during impulse tests on power transformers is proposed, including nonlinear elements, breakdown, and partial discharge events, and an analysis of a layer winding, in the time and frequency domains, with these faults shows that current assessment methods must be used with caution.
Abstract: An objective classification of faults that can occur during impulse tests on power transformers is proposed. It includes nonlinear elements, breakdown, and partial discharge events. An analysis of a layer winding, in the time and frequency domains, with these faults shows that current assessment methods must be used with caution. A model reference approach is proposed to distinctly improve recognition in such cases. The method is immune to changes of wave shape and the instant of fault is available by observation.
35 citations
"Location of breakdown in windings u..." refers background or methods in this paper
...Change in resonant frequency with breakdown for fault location identification [1]....
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...For the sake of simplicity and for benchmarking purposes it has been a practice to consider a uniform layer winding for such studies along with appropriate fault models [1]....
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TL;DR: In this article, a method for recognizing PD events within a winding during impulse tests using a lock-in amplifier technique was proposed. But the method was implemented with a virtual instrument and validated with an independent stand-alone lockin amplifier.
Abstract: A method is proposed for recognizing PD events within a winding during impulse tests using a lock-in amplifier technique. The resonant frequencies of the winding serve as the basis of selection of the lock-in amplifier reference frequencies. It is implemented with a virtual instrument and validated with an independent stand-alone lock-in amplifier. A physical model of a winding with discrete elements is used to demonstrate the results. A theoretical basis for the instrument is established using an 'abc' model of PD along with a linear discrete winding model. The influence of location of PD is also addressed. The method will provide online recognition of PD during the impulse test and can be adapted for onsite measurements.
7 citations
"Location of breakdown in windings u..." refers methods in this paper
...One method of identifying partial discharge events in a power transformer is based on the high frequency behavior of the winding [6]....
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TL;DR: In this paper, a fuzzy logic approach is proposed for identification and classification of faults based on records obtained during impulse tests on transformers, where the outputs of three filters form the basis of identification.
Abstract: A fuzzy logic approach is proposed for identification and classification of faults based on records obtained during impulse tests on transformers. The outputs of three filters form the basis of identification. Experiments are performed on a physical lumped parameter model of a winding to identify breakdown, partial discharge and the presence of non-linear element within the winding. The location of breakdown can also be estimated.
3 citations
"Location of breakdown in windings u..." refers background or methods in this paper
...It has been shown that concurrent measurement of the tank current can help to break the symmetry [2]....
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...One method of locating breakdown in a winding based on current measurements is to compute the change in resonant frequencies of the winding [2]....
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31 Oct 2008
TL;DR: In this paper, a consistent laboratory reproduction of waveforms during impulse tests with solid insulation materials has been a difficult task, and carbon polyethylene composites can serve as benchmarks for such studies.
Abstract: A consistent laboratory reproduction of waveforms during impulse tests with solid insulation materials has been a difficult task. Carbon polyethylene composites can serve as benchmarks for such studies. Experimental results on films and a practical voltage transformer (VT) are shown that can help develop signal analysis tools.
1 citations