Evaluation of Shielding Failure in UHV Transmission Lines by Improving the Simulation in the Corona Phenomenon

Corona phenomena are usually ignored in the numerical helical analysis of transient electromagnetic states or as a phenomenon that negatively affects power systems in analyzes. But in this study, we intend to evaluate the positive effects of corona on lightning strikes in the power system and show that the corona plays an important role in improving the reduction of the overvoltage range of lightning and improving the BIL size of transmission lines. In a high-pressure transmission line, when the voltage amplitude exceeds the intensity of the refractive field that surrounds the air, it occurs in the air around the ionization line, causing a corona to form around the transmission line and increasing the conductor radius. This paper investigates the improvement of the corona model in high-pressure alternating current transmission lines.