PREDICTING VHF/UHF ELECTROMAGNETIC NOISE FROM CORONA ON POWER-LINE CONDUCTORS

A method for predicting VHF/UHF noise generated by corona on power-line conductors in steady rain has been developed. The corona sources are modeled as electric dipoles which are randomly distributed along the conductors and driven by impulsive currents. Each source induces currents on the conductors which turn radiate as traveling-wave antennas. The receiving antenna then respons to the incoherent superposition of the fields from each source. The final formula is a function of the power-line parameters and receiving system characteristics. The most significant result is that the received noise is a strong function of the receiving antenna orientation. The noise is minimized for antennas directed at the line while it is maximized for antennas directed down the line at an angle dependent on the other problem parameters. Lower-frequency (i. e. , 75 MHz) results are in good agreement with experiment.