Distribution Line Carrier: Analysis Procedure and Applications to DG

This paper deals with the analysis of carrier signal transmission in medium-voltage (MV) distribution networks. A multiconductor matrix procedure based on the bus admittance matrix, which accounts for the earth return currents, enables predicting the high-frequency behavior of the distribution networks and, hence, the effectiveness of transmitted signals. To this aim, suitable models have been implemented based on the Carson's theory for overhead lines with ground return and Wedepohl's theory for cable lines. A comparison with the modal analysis demonstrates the advantages of the multiconductor matrix algorithm with respect to the 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 system. In particular, a protection system to prevent the islanding of dispersed generators is proposed. In addition, in a foreseeable hypothesis of allowed islanding operation of portions of distribution networks (microgrids), DLCs are proposed as communication control of the interface device at the point of common coupling.