Relationship Between Corona and Radio Influence on Transmission Lines, Laboratory Studies I-Point and Conductor Corona

Abstract

1. When a quasipeak-type RN meter is used for the measurement of a corona noise, it is advisable to calibrate the meter with a pulse generator. 2. A procedure of calibration and a calibration chart are given. Consistent readings have been obtained for all the meters so calibrated. 3. Within the range of measurements the RN meter readings are linearly proportional to the voltage of square pulses and to the pulse width between 2 and 200 millimicroseconds above which the increase is no longer linear. 4. A given RI level can result from a variety of corona patterns characterized by the number, magnitude polarity, width, and distribution of pulses. These characteristics can sometimes be used to differentiate between the types of corona noise. 5. A good correlation between corona pulses and RI values can be obtained for a given setup if the repetition rate is known for each group of pulses of equal magnitude 6. Sudden jumps of RI were observed when an electrode with sharp points was subjected to a critical voltage. The instability was associated with the onset of corona pulses in the positive half cycle of the applied voltage. 7. Since moist insulating points cause much higher corona pulses and RI than metal points, it is possible that vegetation deposits on transmission-line conductors are more liable to cause RI than are surface imperfections. 8.