Title :
Electrical treeing in extruded polypropylene high voltage cable insulation
Author :
Holto, Jorunn ; Ildstad, Erling
Author_Institution :
Norwegian Univ. of Sci. & Technol., Trondheim, Norway
Abstract :
In this study electrical tree growth in extruded isotactic and syndiotactic polypropylene (i-PP and s-PP) was compared, using a needle-plane geometry. Two main types of treeing were observed, either with one or multiple branches to the ground electrode before breakdown. Highest degree of simple branched trees was found in s-PP. The degree of crystallinity in s-PP was 53% lower than in i-PP and the spherulites size was found to be 5-15 times larger in i-PP than the crystalline areas observed in s-PP. The elasticity modulus for s-PP was half of that measured for i-PP. Despite these differences no significant difference in the propagation rate or time to breakdown during electrical tree growth was found.
Keywords :
earth electrodes; high-voltage engineering; power cable insulation; trees (mathematics); electrical tree growth; extruded isotactic polypropylene; ground electrode; high voltage cable insulation; syndiotactic polypropylene; Elasticity; Electric breakdown; Electrodes; Heating; Insulation; Polymers;
Conference_Titel :
High Voltage Engineering and Application (ICHVE), 2010 International Conference on
Conference_Location :
New Orleans, LA
Print_ISBN :
978-1-4244-8283-2
DOI :
10.1109/ICHVE.2010.5640748
