Broadband Transmission via Underground Medium-Voltage Power Lines - Part II: Capacity

The end-to-end transfer function of three-phase underground medium-voltage broadband over power-lines (MV/BPL) cables with common shield and armor is determined based on a new exact version of the chain scattering matrix method. The various topologies of the underground MV grid are studied with regard to the spectral behavior of the end-to-end attenuation and to the respective capacity and are compared to the corresponding overhead cases. The numerical results reveal that broadband transmission via underground MV power lines depends drastically on the type of cables used and the topology of the underground MV grid. Also, the relaxed power injection limits and the lower noise power levels characterizing underground MV/BPL transmission counteract the extremely high inherent attenuation, making the capacity achieved compatible to that achieved in overhead MV/BPL transmission.