Study of lightning back-flashover performance for 275/ 132kV transmission line by using ATP-EMTP

Abstract

Direct lightning strokes to overhead transmission line towers or to shield wires may cause line insulation breakdown, due to the back-flashover phenomenon which the stroke builds up the voltages across the line insulation and if these voltages equal or exceed the line critical flashover voltage(CFO). Over-voltages which occur on the lines and travel toward the substation can cause damage, particularly to expensive equipment such as transformers, circuit breakers and so on. Thus, the study of lightning back-flashover performance for 275/132 kV Transmission Line has to be made by using ATP-EMTP (The Electromagnetic Transients Program). ATP (alternative transients program) is a universal program system for digital simulation of transient phenomena of electromagnetic as well as electromechanical nature. Demonstration of existed problems in power system can be made in this software and thus, help to solve the problem. Other aspects like tower grounding resistance and lightning current amplitude will be considered in this study as required.