TPWRD Special Issue: Advances in Condition Monitoring and Assessment of Power Equipment

This webinar will first provide an overview on the papers received and published in a recent PWRD's special issue called "Advances in Condition Monitoring and Assessment of Power Equipment". It will also share the impressions of the guest EIC on the R&D trends in this important area. The webinar will then present the best paper selected from the special issue. The paper, entitled "Analytical Expressions to Link SCNF and OCNF of Transformer Windings to Their Inductances and Capacitances for 1-?, 3-? Y and ? Configurations", establishes a mathematical relationship between transformer winding/core movement and the deviation of its frequency responses. This finding has the potential to facilitate a more meaningful interpretation of FRA (frequency response analysis) data, leading to improved transformer condition monitoring. In the main part, a novel approach is presented to derive closed-form analytical expressions that connects harmonic sum of squares of natural frequencies (both SCNF and OCNF) of any winding configuration to its elementary inductances and capacitances. Expressions are derived for all 1-? and 3-? winding configurations. Next, a sneak preview of an application of derived expressions to indirectly measure equivalent air-cored inductance (termed as Leq) of an iron-cored transformer winding, from measured FRA, is discussed. Experiments on 3-?, air-cored, 33 kV, 3.5 MVA winding setup are discussed. Results are cross validated by inductance measurements using an LCR meter. Future thoughts on using Leq as an alternative to leakage reactance measured at 50/60 Hz to provide improved sensitivity for interpreting routine short-circuit test data is discussed. Finally, some insight on using derived expressions to locate radial/axial displacements in Y and ? windings are very briefly presented.