Methodology for the selection of long-mediumvoltage power cable configurations

Single conductor cables are widely used in several types of installations over the last years, including the interconnection of wind parks to the power grid. Owing to the complexity of cable installations each configuration must be treated individually, regarding the use of sheath cross-bonding, the influence of grounding resistances and the use of sheath voltage limiters. In this study, a systematic investigation of the performance of a long-medium-voltage cable configuration is presented. Sheath voltages and currents are calculated during steady-state and short-circuit conditions for varying sheath arrangements using the ATP/EMTP software. Results are validated by field measurements. The analysis is also extended to include the investigation of overvoltages in the installation, during slow and fast transients, according to the basic insulation level for the cable system.