Sequence impedances of insulated cables: Measurements versus computations

The computation of the sequence impedances is a very important topic for insulated cable systems chiefly in HV and EHV levels. This highlights the importance of using reliable procedures in order to compute these impedances since, up to now, their computations are based on simplified formulae. In this paper, results of some measurement campaigns have been compared with both simplified IEC formulae and advanced matrix procedures based on Multiconductor Cell Analysis (MCA) [1, 2, 3, 4]. MCA considers the cable system in its real asymmetry without simplified and approximated hypotheses. One of the advantages of the MCA is the possibility of supplying the cable system with three sequence voltage phasors and of computing the ratios between voltage and current phasors for each phase.