Development and Characterization of a Coupling System for PLC Signal Based on Separable Connector of MV Cable Head

Power line communication (PLC) technology is mostly used in low-voltage (LV) distribution networks for automatic meter reading. On the contrary, its use for medium voltage (MV) power systems requires the use of dedicated and costly PLC couplers. To face this issue and to reduce installation costs, in previous works the authors investigated the feasibility of exploiting some elements already installed in MV networks, such as the capacitive dividers of voltage detective systems (VDSs) in MV substations switchgears [1]-[4]. A different solution was presented in [5], instead, which investigated the possibility of coupling PLC signals by using the capacitive divider embedded in commercial cable separable connector (SC) of MV cables heads. To this end, an ad-hoc characterization and design of the SC-based PLC coupling system was carried out. Firstly, impedance measurements have been performed to characterize the cable head behavior in the frequency range of interest. An equivalent circuit model has been obtained and it has been used to design the SC-based coupler prototype. Simulations and experimental tests have been performed in FCC above CENELEC frequency band, to analyze both the channel frequency response and the transmission performances. Starting from the earlier research works on VDS-based coupling solution, a summary of the work on SC-based PLC coupling system is given in the following, focusing the attention on the main steps of the development and characterization of the SC-based solution, together with a selection of experimental tests made in laboratory environment for the system prototype validation.