Corona Phenomena for long-term operating conductor under different weather conditions

Corona discharge in the transmission lines was affected by the surface condition of the conductor, which was different between the long-term operating conductor and the new ones. The rainy weather conditions have conspicuous influence corona discharge for the surface of conductors would be filled with the drops of rainwater, hence, the electric field around the conductors will be distorted. Corona cage is audible noise effective and economical means for duplicating corona progress in power transmission lines with lower voltage on the conductor in the cage. The long-term operated conductor and the same type new ones were utilized in this experiment under fine (0 rainy rate), and other 3 different rainy rate conditions. The corona phenomenon, audible noise level and radio interference level were recorded and compared. Under the different conditions, the corona discharge turned to be more intense for the long-term operating conductor compare to the new ones; however, under the heavy rainy condition, the deviation between the long-term operating conductor and the new ones was reduced, it was due to the corona caused by the water drops around the conductors when the applied voltage and the rainy rate are high.