The Propagation and Identification of Partial Discharge Signals in Transformer Bushing Under the Framework of Digital Twins

Abstract

The capacitive high-voltage bushing, as one of the typical oil-paper insulated devices, is the only electrical device that bears both external and internal insulation, and is also one of the important components of transformers. In recent years, transformer bushing accidents due to partial discharge (PD) have occurred frequently, affecting the safe and stable operation of the entire power grid. With the development of sensing technology and information processing technology, digital twins have gradually appeared in people's views, and more and more researchers have started to adopt digital twins for condition assessment and diagnosis of power equipment. In this paper, a virtual simulation model and a distributed circuit model of a 330 kV high-voltage bushing are built to study the propagation characteristics of PD signals in the bushing and to verify the feasibility of applying digital twins to the identification of discharge signals. The study found that the waveform distortion and attenuation occur during the process of propagation in the bushing, but this does not affect the separability of the different types of discharge signals, and the application of digital twins to the identification of discharge signals is feasible.