A study on the Correlation Between the PD Pattern and the Type of Electrical Trees Propagating in the XLPE Insulation for the Underground Power Transmission Cable

Abstract

In this work, the correlation between the PD patterns and the electrical tree propagation has been investigated by use of the specimen removed from the insulation of the real 154 kV XLPE underground power cables. As a result, it could be deduced that the PD pattern regarding electrical trees depends on their types which could be classified into three different distinct groups such as branch, bush and branch-bush mixed. Considering the results of our investigation, if the partial discharge magnitude is only considered for the diagnosis of the cable system, it is possible to draw a wrong decision. Therefore, it is possible to propose that the time characteristics of PD patterns should be taken into account for the diagnosis of the cable system in addition to the conventional Φ-q-n characteristics.