Investigating the Sensitivity of Frequency Response Function to Parameters in Equivalent Circuit of Transformer Winding Based on Two FRA Measurement Connection Ways

摘要

As a reliable and non-destructive technique, frequency response analysis (FRA) has been widely recognized for transformer winding deformation detection and assessment. In this paper, frequency response function (FRF) are obtained by two different FRA measurement connection ways, namely end to end voltage ratio and transfer voltage ratio measurements. At the same time, according to the two ways, sensitivity of the FRFs to electrical parameters of the equivalent circuit model of the transformer winding are investigated. Based on Tellegen theorem, adjoint network method is derived to calculate the values of the sensitivity of FRF to parameters. By comparing the results of two ways, the variation laws of the sensitivity from the two different connection ways are determined. Besides, this study will give us a more deep-lever and accuracy understanding how the variation of parameters influence on the FRA results.