en Direct Lightning Direct Lightning Research Paper Research Paper <div style="text-align: justify;"><span style="font-family:Times New Roman;"><span style="font-size:14px;"><span style="color:#000000;">Lightning is the main factor of outage and insulation breakdown of power system. The lightning event can produce dangerous overvoltage, equipment failures, and power supply interruption. In this paper, externally gapped Line arresters (EGLAs) performances have been investigated to evaluate the lightning performances of a typical 63&nbsp;kV transmission line. A probabilistic analysis has been done to study the EGLA performance in transmission line by Monte-Carlo method. The results show the EGLA performance dependency to soil resistivity and lightning strike parameters.</span></span></span></div> Externally Gapped Line Arrester, Insulation Breakdown, Nonlinear Resistor, Overvoltage. 131 140 http://ijeee.iust.ac.ir/browse.php?a_code=A-10-1017-1&slc_lang=en&sid=1 M. Khodsuz m.khodsouz@mazust.ac.ir 1800319475328460013431 1800319475328460013431 Yes Faculty of Electrical and Computer Engineering, University of Science and Technology of Mazandaran, Behshahr, Iran.