Toward a Novel Characterization of Transformer Interturn Faults Based on Arc-Induced Transients in Winding Magnetomotive Force

A transformer interturn short-circuit fault generally emerges as an arc shorting adjacent turns along the winding. If not identified and isolated in time, it may develop into a more serious fault and result in destructive accidents. For a long time, accurate, rapid, and sensitive identification of transformer interturn faults has been highly challenging. In this article, a novel characterization method for transformer interturn short-circuit faults is proposed based on the transients induced by the zero-off effect of a fault arc. Specifically, the variation in the winding magnetomotive force is constructed as a characterization variable, where the presence or absence of arc-induced transients within it indicates whether an interturn fault occurs. The performance of the proposed method is evaluated through coupled field-circuit simulations and experiments, demonstrating that it can fast and accurately characterize interturn faults of different severities and locations. Unlike conventional methods using fault features at power frequency, the unique transient fault signatures in this study can offer new insights into addressing the intractable issue of transformer interturn fault identification.