INVESTIGATING THE EFFECTS OF DISC INSULATOR TYPE AND CORONA RING ON VOLTAGE DISTRIBUTION OVER 230-KV INSULATOR STRING USING 3-D FEM

The voltage distribution of insulator strings, which are very common in the suspension of overhead transmission systems, is greatly uneven. So the calculation of the voltage distribution along them is a very important factor in the design of the insulators. Also, no remarkable endeavour regarding the impact of insulator material and profile upon the electric field and voltage distribution has been made so far. In this paper several 230-kV insulator strings with different porcelain and glass units were simulated and their voltage distributions were compared, to investigate the effect of insulator types on this quantity. Also the effect of corona ring on potential distribution over insulator strings with different insulator types was investigated. Reported results show the dependency of voltage distribution to insulator material and profile.