Corona inception field of typical overhead line conductors under variable atmospheric conditions

Corona inception field of line conductors is of major importance for assessing corona performance of overhead transmission lines. Using computational models that consider the ionization processes in corona discharge, the corona inception field of ACSR conductors typically utilized in overhead transmission lines is estimated. The interactive effects of line conductor geometry, voltage polarity as well as atmospheric conditions on corona inception field are assessed and discussed based on the ionization area around the conductor. It is shown that the corona inception field of bundle configurations can be satisfactorily approximated by that of the subconductor when considered single. Generally, the inception field of negative corona is slightly lower than that of positive corona and lesser affected by variations in atmospheric conditions. An empirical expression for the straight. forward estimation of the corona inception field of line conductors has been introduced, accounting well for the effects of conductor geometry, voltage polarity and atmospheric conditions.