Distribution Line Carrier: Analysis Procedure and Applications to DG

The paper deals with analysis of carrier signals transmission in MV distribution networks. A multiconductor matrix procedure based on bus admittance matrix, which accounts for the earth return currents, allows predicting the high frequency behaviour of distribution networks and hence the effectiveness of transmitted signals. To this aim suitable models have been implemented based of the Carson´s theory for overhead lines with ground return and Wedephol´s theory for cable lines. A comparison with the modal analysis demonstrates the advantages of multiconductor matrix algorithm with respect to modal analysis. In order to validate the theoretical results two measurement campaigns have been carried out on real MV networks. A good agreement between measured and computed values has been verified. Since distribution networks are generally unlike each other, the procedure becomes a valuable tool, which makes it easy to assess the feasibility of distribution line carrier (DLC) applications in any given system. In particular a protection system to prevent islanding of dispersed generators is proposed. In addition, in a foreseeable hypothesis of allowed islanding operation of portions of distribution networks (microgrids), DLC are proposed as communication control of the interface device at the point of common coupling