Simulation Analysis of Transient Response of Weathering Angle Steel Tower under Lightning Current Impact

The impact impedance of the transmission line tower is an important parameter to evaluate the lightning counterattack performance. After the tower is struck by lightning, the potential at the top of the tower rises, which may cause lightning counterattack flashover on the insulator on the tower. Weathering steel tower materials are different from traditional galvanized steel pole towers. Weathering steel in natural environments has shown that it will gradually form a protective dense rust layer, which will reduce the steel's electrical conductivity. This phenomenon may lead to an increase in the surge resistance of the tower and an increased risk of the insulator hitting back flashover. This article uses SolidWords 3D drawing software to model the tower, and imports the model into the FDTD simulation software to perform the electromagnetic simulation calculation of the tower lightning strike. Compares the transient response of the lightning strike weathering angle steel tower and the galvanized steel tower. Calculate the withstand voltage of the upper-phase insulator and the transient potential rise at the bottom of the tower, and draw the following conclusion: when the impact grounding resistance is 7Ω, according to the 61kA lightning-resistant design level requirements, the withstand voltage of the phase insulation on the weathering angle steel tower Will reach 1.55MV, exceeding the pure galvanized steel pole tower 0.55MV; when the impact grounding resistance is 15Ω, according to the 50kA lightning-resistant design level requirements, the weathering angle steel pole tower phase insulation withstand voltage will reach 1.54MV, exceeding the pure galvanized steel pole tower 0.51MV. If the weathering angle steel pole tower adopts the same insulation measures as the galvanized steel pole tower, it will have a certain risk of lightning protection.