A study of inception and growth of water trees and electrochemical trees in PE and XLPE insulation

This paper presents an experimental investigation on frequency acceleration of water treeing and on the effect of different factors, such as humidity content, different contaminants, temperature and field strength on tree growth in PE and XLPE. For this investigation model test specimens have been used to supplement cables for testing. Coloured trees and their points of initiation have been analysed for their content of impurity elements and are found always to contain sulphur and some metal.