An investigation of the performance of underground cable installations in operational and fault conditions

The widespread use of underground single core power cables has led to the necessity of investigation of the performance of cable installations in operational and fault conditions, especially due to the complexity of each case. In this paper the induced voltage and current distribution along cable sheaths is calculated for a medium voltage cable configuration using the ATP/EMTP simulation software, while the validity of all available simulation models is examined in the analysis. The implementation of several grounding, sheath cross-bonding and cable transposition techniques is thoroughly investigated in order to reduce sheath voltages below the permissible levels and also maintain low sheath currents and losses. The analysis also includes the influence of the number of joints and the cable length on the performance of the underground installations.