en High Voltage Engineering High Voltage Engineering Research Paper Research Paper <div style="text-align: justify;"><span style="font-size:14px;"><span style="font-family:times new roman;"><span style="color:#000000;">Since the insulators of transmission lines are exposed to different environmental conditions, it is important task to study insulators performance under different conditions. In this paper, silicone rubber insulators performance under different environmental conditions including rainy, icy, salt and cement are proposed and exactly is studied. Electric fields (E-fields) and voltage distributions along the insulator under various conditions have been evaluated. Moreover, the corona rings effects on insulator performance under these conditions have been presented. A 230&nbsp;kV silicone rubber insulator is selected, modeled and simulated with finite element method (FEM) using the COMSOL software. The simulation is repeated for different environmental conditions and efficiency of corona ring for each scenario is evaluated. The results indicate that environmental conditions have a significant effect on the insulator performance and the corona ring somewhat alleviate the adverse effect of environmental conditions on the insulator performance.</span></span></span></div> Corona Ring,Electric Field,Finite Element Method (FEM),Insulator,Potential Distribution,Rubber Insulator, 375 385 http://ijeee.iust.ac.ir/browse.php?a_code=A-10-2818-1&slc_lang=en&sid=1 S. Hajiaghasi s.hajiaghasi@gmail.com 180031947532846007733 180031947532846007733 No Faculty of Electrical Engineering, Shahid Beheshti University (SBU), Tehran, Iran. Z. Rafiee z_rafiee@sbu.ac.ir 180031947532846007734 180031947532846007734 Yes Faculty of Electrical Engineering, Shahid Beheshti University (SBU), Tehran, Iran. A. Salemnia A_Salemnia@sbu.ac.ir 180031947532846007735 180031947532846007735 No Faculty of Electrical Engineering, Shahid Beheshti University (SBU), Tehran, Iran. T. Soleymani Aghdam T_Soleymani@sbu.ac.ir 180031947532846007736 180031947532846007736 No Faculty of Electrical Engineering, Shahid Beheshti University (SBU), Tehran, Iran.