COMPUTATION OF EM1 FIELDS GENERATED DUE TO CORONA ON HIGH VOLTAGE OVER HEAD PO.WER TRANSMISSION LINES

ABSTRACT- Corona generated pulsed currents on high voltage transmission line conductors radiate electromagnetic field, which inturn can interfere with communication systems, radio as well as television receivers operating nearby. In this paper, corona generated electromagnetic interference (EMI) field in dB at an observation point near the ground has been computed assuming ground as a perfect conductor. It has been observed that the interference field starts abruptly at the corona inception voltage and it increases with the voltage stress on the conductor. It is also observed that the EM1 field reduces with increase in lateral distance and also with increase in frequency as well as the conductor diameters for the same line voltage. 1