ON THE PARTICLE-INITIATED BREAKDOWN OF SF6 INSULATED CABLES

The excellent insulation properties of compressed sulphur hexafluoride (SF6) are adversely affected by metallic-particle contamination in practical compressed-gas insulated cables (GIC). The movement of such particles is random and the particles play a crucial role in determining the insulation behavior of GIC. This paper reports some calculations of the breakdown probability of compressed SF6 when aluminum wire particles are present in a coaxial conductor system. The motion of the particles is studied using a computational algorithm which takes into account the change in the particle charge during its movement.