Distribution Voltage of Quadruple Circuit Dual Voltage Tower Model During Lightning Strike

Lightning strikes on transmission lines often triggers electrical blackout. A direct lightning strike to the ground wire or the structure of tower makes voltage rise along the tower and the voltage stress appear along the installed string insulators at the tower. A back flashover occurs as the voltage along the string insulator exceeds the maximum insulator withstand. Most of previous works carried out the impact of lightning strike for conventional tower with single voltage and maximum two circuits. In this report, the assignment was carried out by modelling the quadruple circuit dual voltage tower model. The tower carries two circuits with 500kV and other two circuits with 150kV working voltage. In this work, an approach to estimate passive element of tower impedance surge was implemented and then it is followed by several experiments through a simulations program to investigate to determine voltage stress of each stage of tower and the string insulations.

Keywords: Tower Transmission, Lightning Strike, Impulse Voltage Stress