A Novel Characterization Method for Transformer Interturn Short-Circuit Faults Based on Arc-Induced Transients

This digest proposes a novel characterization method for transformer interturn short-circuit faults using the transients in the change of winding magnetomotive force (MMF) caused by the zero-off effect of the fault arc. To enhance the clarity and regularity of these transient features, the signals of winding MMF variations are analyzed using variational mode decomposition (VMD), with the optimized VMD parameters selected by particle swarm optimization (PSO). To validate this characterization method, calculations and experiments for interturn short-circuit faults are carried out on a specifically designed transformer. The results confirm that the arc resistance as a load induces transients in the change of winding MMF as the short-circuit circulating current passes through zero, affirming the viability of this characterization method for actual interturn fault identification applications.