In GIS disconnector

insulated pull rod is the connection between high voltage parts and grounding potential parts

so it suffers a significant voltage drop. And due to the mechanical movement

it’s possible to produce some particles

or mechanical damage on insulated pull rod

which may impact on electric field distribution. This paper mainly focuses on the impacts of foreign materials and defects with diverse factors on the insulated pull rod

to provide references and guidance for structural design

manufacturing

etc. First

with a common 550 kV GIS disconnector structure and its operating condition

3D finite element method is performed and the distribution of potential and electric field have been calculated. Then

comparisons and analysis have been done

including surface defects and foreign material with different size

and locations. At last

the correlation between defects and the electric field distribution have been systematically analyzed. According to the results

adhering metal particles on insulated pull rod are the most dangerous for field distortion. And surface defects close to the low voltage parts are more likely to cause flashover. Based on the research achievements

practical advices for the manufacturing and quality criteria of insulated pull rod are proposed.