Mobility estimation in polymeric insulation through space charge profiles derived by PEA measurements

Inference of apparent mobility of charge carriers in polymeric materials by means of space charge measurements performed during depolarization is presented in this paper. New expressions are proposed here, which are alternative to those already developed in a previous work, both applicable to space charge quantities measured during depolarization. These expressions are applied to the results of space charge measurements performed on unaged and aged XLPE insulation for HVDC cables. It is shown that the two approaches provide close apparent mobility estimations (as a function of depolarization time), which also agree with some literature data. Hence, it can be speculated that the results thus obtained support the validity of both approaches.