Partial Discharge Detection and Characteristics of Gas-insulated Substation Free Metal Particles Based on Acoustic Emission

摘要

Metal particles can easily be produced in the production and installation of a gas-insulated substation (GIS). The partial discharge (PD) induced by metal particles is a significant security risk to GIS. At present, some related research studies focus on the PD of individual metal particles, but less attention is paid to that of accumulated metal particles. In this study, the PD of the accumulated metal particles was investigated. A defect model of surface free metal particles on a basin-type insulator was set up. Four models of free metal particles of different sizes lying inside the GIS were designed. PD signal waveforms were measured using acoustic emission (AE) sensors. The frequency spectrum characteristics of the PD signal were analyzed, and the PD characteristics under different voltage waveforms were compared. Research results showed that, through the detection of PD signals, the accumulation of free metal particles on the surface of the insulator could be predicted and evaluated to ensure the safe operation of GIS equipment.