Relevance of the charging period to the dielectric response based diagnosis of PE/XLPE cables

The measurement of the so-called dielectric response is one of the approaches for nondestructive insulation diagnosis. In the frequency domain the dielectric response can be obtained by capacitance and dissipation factor measurements, in time domain by depolarisation and polarisation current or recovery voltage measurements. The paper presents dielectric response measurements of different aged and unaged XLPE-insulated medium voltage cables in dependence of the required charging period prior to the time domain measurement. Furthermore, the results are compared to results of destructive test methods