Insights from salt-fog testing on high-voltage insulators used in HVDC converter stations

This paper provides a technical overview of Terna’s experience with salt-fog testing on highvoltage insulators used in HVDC converter stations. The motivation behind this work stems from the critical role of insulators in ensuring the reliability of power systems exposed to harsh environmental conditions. Coastal proximity, industrial pollution, and dust accumulation can significantly impair insulation performance, especially for DC applications where field experience remains limited. The main goal of the paper is therefore to consolidate the results of multiple test campaigns and compare the presented procedure with international standards.