THE EFFECT OF RANDOMLY EARTHED GROUND WIRES ON PLC TRANSMISSION - A SIMULATION EXPERIMENT

Power line ground wires are discretely bonded to earth along the line at each tower. When the spacing between towers is constant and approaches a multiple of one half wavelength at the operating frequency, abrupt variations in the propagation parameters occur, that would affect carrier transmission performance at the vicinity of certain critical frequencies. In practice the spacing between towers is not exactly constant and one may wish to know the result of taking this circumstance into account. The analysis and numerical results presented in this paper show that even slight random perturbations of line periodicity are sufficient to render unnoticeable any sharp variations in attenuation, velocity and surge impedance, one might be led to expect from the analysis of the strictly periodic case. © 1990 IEEE