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Sweep Frequency Response Analysis is a proven test technique for condition monitoring of transformers. Detection of the change in geometry of core and coil assembly is the major intent of this test. With the experience of about a decade or two, the experts have laid out guidelines for this analysis to asses the electrical & mechanical health of this assembly. Though it is looked at as a tool to...
Many problems can arise in power transformers, beginning from the moment they arrive at the sites where they are to be installed [1], [2]. Sweep frequency response analysis (SFRA) is used by many industries and manufacturers to assess the mechanical integrity of the core, winding, and clamping structure of power transformers. It usually involves the application of low-voltage (LV) signal (2 to 15...
In the advanced maintenance techniques of the transformer, Sweep Frequency Response Analysis(SFRA) method is one of the established technique that includes the modelling of the transformer frequency response. This includes identifying the transfer function and realising into circuit parameters so that the incipient fault detection is correlated with the changes in the circuit parameters. A fractional...
Many methods have been developed to justify the condition of power transformer; one of the newest and well known is by using sweep frequency response analysis techniques. The basic concept of this method is by injecting a constant-amplitude of sinusoidal signal under various frequencies (sweep). The current result then compared to the former frequency response (under normal condition) to evaluate...
Nowadays, Sweep FRA becomes a common measurement tool used to identify the transformer condition. The standard for this technique and how to interpret the result has been released by CIGRE and IEEE. PT PLN P3BJB is operating 787 transformers from various voltage ratios. Most of the transformers are 150/20 kV (64.4%) and there are 35 transformers operated in 500/150 kV. Each of the transformers is...
The sweep frequency response analysis (SFRA) is an analysis technique for detecting winding displacement and deformation (among other mechanical and electrical failures) in power and distribution transformers. SFRA as a diagnostic technique must integrate both off-line measurements and interpretation of the data in order to provide an assessment of the condition of the windings. The record interpretation...
The measurement of the frequency response on power and distribution transformers is a diagnostic test technique for detecting winding displacement and deformation (among other mechanical and electrical failures), which are among the most important causes of mechanical failure in transformers. There are two different methods to carry out the measurement of frequency response: sweep frequency response...
Sweep frequency response analysis (SFRA) is one of the most powerful diagnostic tools for assessing mechanical damage to a transformer winding. Analysis of the results, which are in the form of frequency response traces can, however, be daunting to new users. One approach is to attempt automated analysis, and this paper presents an approach using cross- correlation coefficients. This is a power signal...
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