Using SF

6

or SF

6

/N

2

mixed gas as insulation medium

GIS/GIL has the characteristics of large capacity

high reliability

and environmental friendliness. Especially it has a great application prospect in the field of UHV transmission and offshore transmission of large-scale wind power. But the metal particle contamination in GIS/GIL is the key technical problem to improve the equipment insulation strength. We introduce the charged mechanism and stress analysis of a metal particle in GIS/GIL

and analyze the influences of AC

DC or impulse voltages on particle motion and GIS/GIL insulation. Furthermore

we compare the typical insulation faults of GIS/GIL caused by particle contamination

namely the gap breakdown caused by moving particles and surface flashover on insulator adhered by particles. In addition

we summarize the curren

t main particle suppression measures and their mechanisms. Finally

we point out the defects of the existing researches in particle pollution of GIS/GIL and put forward some possible solutions.