Abstract
This paper presents an investigation on the sensitivity of frequency response of a 500 kVA, 11/0.433 kV distribution transformer with and without the presence of a winding clamping structure. Frequency response analysis (FRA) measurements of multiple test configurations were carried out with and without the presence of a winding clamping structure. Statistical analyses based on Pearson’s correlation coefficient (PCC), Spearman’s correlation coefficient (SCC), Kendall’s correlation coefficient (KCC), cross-correlation coefficient (CCF), root mean square error (RMSE), absolute sum of logarithmic error (ASLE), hypothesis test (F-test) and relative factor (RF) were applied to determine the effect of the winding clamping structure. It was found that the removal of the winding clamping structure has an impact on the frequency response signature at the frequency less than 2 kHz during offline measurement. It was found that ASLE and F-test are suitable methods that can be used to indicate the variation of frequency response caused by clamping structure removal of the distribution transformer under study.
Highlights
Frequency response analysis (FRA) is a common non-destructive testing method used by utilities to monitor the mechanical integrity of transformer windings [1]
This study aims to investigate the effect of clamping on the frequency response signature of a distribution transformer
Statistical methods such as Pearson’s/Spearman’s/Kendall’s tau/cross correlation coefficients, relative factor (RF), absolute sum of logarithmic error (ASLE), root mean square error (RMSE), hypothesis test (F-test) were used for interpretation of the changes observed in the winding structure before and after removal of the clamping structure
Summary
Frequency response analysis (FRA) is a common non-destructive testing method used by utilities to monitor the mechanical integrity of transformer windings [1]. FRA measurement is sensitive towards mechanical changes in the winding. Several statistical and artificial intelligence (AI) techniques have been proposed for interpretation of mechanical changes in transformer windings based on FRA. Statistical techniques such as correlation coefficient (CC), absolute sum of logarithmic error (ASLE), minimum-maximum ratio (MM) and absolute average difference (DABS) have been proposed for the interpretation purpose in [3,4,5,6,7,8,9]. The Pearson’s correlation coefficient (PCC), Spearman’s correlation coefficient (SCC) and Kendall’s correlation coefficient (KCC) are compared in [10,11,12] using
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
