Equivalent Multi-Surge Impedance Model of Transmission Line Towers

摘要

To analyze exactly the wave propagation processes of a transmission tower when lightning strikes, an equivalent model of a transmission tower was studied in this paper. First, based on the correlative theory of tapered antenna, an equivalent surge impedance model of a single stanchion of tower was made. This tower was regarded as a four-conductor system according to the real configuration of a tower, and the equivalent impedance of the four-conductor system was obtained by multiplying the single pillar impedance with the compensation factor. Combined with the definition of wave impedance regarded with inductance and capacitance, the compensation factor of the four-conductor system was introduced. Then, the bracings equivalent model was obtained based on the analysis of the effect of bracings on the main body of a tower, and an equivalent impedance model of the crossarms was built base on the correlation theory of the equivalent model of parallel multi-conductors. In modularizing the tower model, the equivalent impedance of the tower was found. Finally, a 500 kV tower was calculated in this paper using the equivalent impedance model of the tower.%W artykule przedstawiono badania propagacji fali w energetycznej wie?y transmisyjnej, po uderzeniu pioruna. Analiz? przeprowadzono na podstawie modu?owego modelu anteny w dwóch etapach. Najpierw stworzono model impedancyjny przepi?cia w wierzy jedno-podporowej, a nast?pnie uwzgl?dniono elementy usztywniaj?ce. Wykonano przyk?adowe obliczenia dla wie?y pracuj?cej przy napi?ciu 500 kV.