Application of Frequency Response Analysis for Diagnosis of Abnormality of Shunt Reactor

Frequency response analysis (FRA) is a powerful technique to detect abnormalities of windings of power transformers such as deformations and displacements of winding. FRA would be applicable to detect abnormality of shunt reactors because configurations of windings are similar to those of power transformers. In this study, FRA is applied to a shunt reactor. In the studied shunt reactor, acetylene gas was detected in dissolved gas analysis. In FRA, measured transfer functions are compared with those of a sister unit and a shift of a resonant frequency in the transfer function of the W phase is found. This indicates that the studied shunt reactor has some abnormality in the W phase. To investigate abnormality aspect, a circuit model of the shunt reactor is established. Transfer functions…