A unified approach to characterizing medium to low voltage powerline communication channels

For Powerline Communications (PLC) between Medium Voltage (MV) and Low Voltage (LV) sections of power grids, passing the signals `through' rather than `around' transformers is always preferable in terms of costs and safety hazards. However, this decision is often based on the transfer characteristics of the isolated transformer, as there is no benchmark method of evaluating PLC signal losses on these paths. This paper proposes a `unified' approach to PLC channel characterization, by concurrently considering the effect various impedances have on the channel communication interfaces. An experimental MV/LV grid consisting of line traps, couplers and a transformer was designed using this approach and simulated to determine insertion losses in the CENELEC band. Results show remarkable differences between the transformer characteristics in isolation and when included in the unified channel, thereby demonstrating the effectiveness of the approach for a realistic determination of PLC MV/LV channel characteristics with distribution transformers inclusive.