A novel approach for on-line deformation diagnostics of transformer windings

This paper discusses an elegantly simple on-line approach for deformation diagnostics of transformer winding. The Current Deviation Coefficient (CDC) derived from terminal current measurements at a selected high frequency (HF) is found to be an effective indicator for locating deformed section of the winding. Also, any deviations of HF terminal currents from their fingerprint values can be used to find the extent of deformation. An on-line method for detecting winding deformations in three-phase star- or delta-connected winding is also elaborated in the paper. Finally, a proposal for simultaneous on-line monitoring of HV and LV windings using the novel on-line approach is discussed.