Corona power loss calculation for three-phase transmission lines

A method is developed for calculating the power loss due to corona on three-phase transmission lines. It is assumed that emission of ions from the phase conductors into the surrounding space takes place when the conductor surface field exceeds the onset value for corona. The space charges are simulated by discrete line charges, and the charge simulation technique is used to calculate the charge emission from the phase conductors during corona periods over both the positive and negative half cycles. The ion emission is influenced by the charge induced on the phase conductors owing to the presence of other phases. The determination of the induced charge is discussed in detail. The displacement of the space charges is governed by the prevailing field, which is the sum of the contributions of all the discrete line charges, including those simulating the phase conductors themselves. The calculated corona power loss values agreed well with those measured experimentally for a test line.<>