Fault Analysis of GIS Basin Insulator Based on Laser Ultrasonic Detection Technology

GIS equipment is widely used in power network and its reliability directly affects the safe and stable operation of power network. In this paper, a case of breakdown fault of 220kV GIS basin insulator is analyzed deeply. The fault gas chamber position is determined according to the fault recording diagram, SF6 gas decomposition products and other fault characteristics. Combined with laser ultrasonic testing instrument and spot disintegration inspection, the reasons for breakdown of GIS busbar basin insulator are analyzed comprehensively. It is confirmed that the basin insulator has cracks caused by uneven tightening torque of nuts on both sides of flange and damp flange gap. The electric field is distorted at the crack, causing the discharge along the surface. Finally, according to the cause of the fault, the follow-up measures for this kind of fault are put forward.