Abstract
An experimental investigation was performed on a UHV gantry tower model for the EMTP calculation of lightning overvoltage at substation. The various lightning surge response characteristics were measured on a 1/10 scale UHV gantry tower. We present the comparison between measured and calculated voltage waveforms at various point of gantry tower. It showed that measured waveforms were not reproduced in the conventional EMTP model. It was estimated that it did not take horizontal element into consideration. Since then, the model was improved in new model, which had a horizontal element. Measured waveforms were reproduced by the improved EMTP model. Surge impedance of the improved model is as the next. Vertical element is 220-ohm, horizontal element is 140-ohm.
