Localization of mechanical deformations in transformer windings using time-domain representation of response functions
2014 (English)In: European transactions on electrical power, ISSN 1430-144X, E-ISSN 1546-3109, Vol. 24, no 1, 16-29 p.Article in journal (Refereed) Published
Time domain reflectometry (TDR) has been used for localization of discontinuities in transmission lines in diverse applications. In this paper, its potential as an alternative to frequency response analysis for the detection and localization of mechanical changes (damages) in transformer windings is investigated. This is done by computer simulations of a lumped-element circuit model of a disc winding which has been verified with measurements on an experimental coil. We also suggest that the idea of TDR can be used to visualize the results of frequency response measurements in time domain, where they are easier to interpret. When applying TDR to transformer windings instead of transmission lines, two main new problems have to be addressed, namely (i) the basic inhomogeneity of most winding designs, and (ii) the strong effect of dispersion (distortion of signals as they travel along the winding). We argue that TDR is still useful under these circumstances if it is applied as a differential method and in the right frequency window, i.e. using signals of suitable shapes. Under these conditions, it allows the detection and, to some extent, localization of certain mechanical changes in a transformer winding.
Place, publisher, year, edition, pages
2014. Vol. 24, no 1, 16-29 p.
transformer winding, frequency response analysis, time domain reflectometry, winding deformation
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-106817DOI: 10.1002/etep.1683ISI: 000330641900002ScopusID: 2-s2.0-84900802559OAI: oai:DiVA.org:kth-106817DiVA: diva2:574229
QC 201403072012-12-042012-12-042014-03-07Bibliographically approved