The effect of semiconductive screens and XLPE insulation combinations on electrical tree inception [in power cables]

Electrical tree inception tests have been carried out on different combinations of semiconductive screen (semicon) needle/XLPE insulation samples. The test programme has been designed so that it is possible to ascertain the main factors which promote or retard electrical tree inception. The results obtained have permitted predictions to be made of the most appropriate material combinations to give "good" and "poor" performance. These "good" and "poor" material combinations were then tested to verify the predictions. The results show that the experimentally measured performances agree with their predicted performances. Thus it can be concluded that by careful design and selection of semicon/XLPE combinations, samples with enhanced electrical treeing properties can be manufactured.