Lightning surge response of a double-circuit transmission tower with incoming lines to a substation through FDTD simulation

A transmission tower model that can reproduce the lightning surge response is important for analyzing the lightning surge. In developing such tower model, however, studies have been conducted using a stand-alone tower or a condition where the tower and transmission lines are orthogonally crossed. This could be attributable to the difficulty in handling a complex layout in conventional experiments and theoretical studies. The present paper verifies the accuracy of the FDTD analysis, based on a comparison with the experimental results. Subsequently, it studies the influence of the layout and the inclined angle of the incoming lines to the substation on the surge response of the tower under near-real facility conditions via electromagnetic field analysis using the FDTD method. As a result, the voltage of the insulator strings peaked with a zero-degree incoming angle and it declined with increasing angle, namely by about 20% when the inclined angle was 37.5 degrees. Finally, the current waveform was analyzed in addition to the voltage characteristics and the generation mechanism of the line voltage was explained.