The lightning contingency probability analysis on transmission tower with line arresters protection

The contingency probability analysis on transmission tower under lightning stroke with various configurations of line arresters is proposed in this paper. The simulation and calculated approach is developed to evaluate the performance for different line arrester installed scheme and capacity. The Electro-Magnetic Transients Program (EMTP) is used to simulate the effect of system under lightning strike on transmission system. The considered components of the study system including lightning surge, line arrester, transmission line and tower. All of the components are modeled to fit the situation of Taiwan under EMTP for more realistic purpose. Then, the proposed simulation procedure is applied to calculate the failure probability of the line arrester by considering the random properties of lighting current, including the wave-tail and peak value of the lightning surge. The comparative studies, which considering the thermal capacity, number of installed arresters, installation position of the arresters, and the footing resistance of transmission tower, are conducted to provide appropriate suggestion for installation strategies of the line arrester. Results obtained from this study can provide the electric utility with valuable quantitative information due to the cost-benefit analysis for the installing of line arrester.