Narrowband Modeling of Single-Wire Earth Return Distribution Lines

The implementation of powerline communication (PLC) on single-wire earth return (SWER) grids requires high-frequency earth path characterization. The empirical determination of these characteristics is not practical for large grids. Analytical expressions may be used to estimate the high-frequency characteristics of earth paths; however, this paper shows that this approach can lead to errors when modeling line-to-earth path PLC channels. Therefore, a hybrid empirical/analytical earth path characterization method, based on heuristic correlations of measurement results with a lossy capacitor model, is hereby proposed. Further measurements on an experimental SWER line using two types of conductors were carried out. The results indicate that narrowband PLC implementation on SWER grids is feasible, and that conductors with similar size and material composition may have similar high-frequency characteristics, regardless of the construction method used. The proposed earth path characterization method was verified by comparing measurements with simulations of frequency-dependent analytical and constant parameter hybrid, per-unit SWER transmission line models.