Linear particles behavior caused by circuit breaker action in GIS

摘要

The linear metallic particles which are static lying on the GIS enclosure have less harmful to the insulating property. However, the insulating property will reduce in a large degree when the metallic particles once stand and beat in the GIS cavity. Many papers have discussed the behavior of linear particle in the GIS affected by the type and shape of the particles, the pressure of the gas insulation, and the electric field, however, very little research has been conducted on the behavior of linear particles under the mechanical impact caused by the operation of circuit breaker. In this study, an impact vibration test platform is built to investigate the deterioration of the gas dielectric strength in a 126kV prototype proportion shrinking GIS. A high speed camera is applied to record the movement behavior of the particle. The experiments are repeated with different size of linear particles. The deterioration of the dielectric strength under different voltage are discussed, and the movement characteristics are presented. The results indicate that: the impact force reduces the lift voltage of linear particles, e.g. the lift voltage of a particle with 15mm length and 0.3mm radius decreased from 36kV to 25kV. Secondly, the lift voltage drop ratio decreased with the size of the particles under the same impact force. Finally, movement characteristics of linear particles after lifting are different, the particle rotates and bounces between conductor and GIS tank without impact force, apart from that, the particle may stand on the shell after lifting with impact force.