Lighting performance study on existing 275KV overhead line in TNB system

Abstract

Lightning is the primary cause of tripping for most overhead power transmission lines. Few methods have heen discovered to estimate the lightning performance of a transmission line. However these methods are not properly defined due to the nature of lightning which is difficult to analyze and model. Studies are continually being done to discover alternative methods that can be implemented to improve the lighting performance of transmission lines in addition to the standard methods such as adding Overhead Ground Wires (OHGW), reducing ground resistance, adding counterpoise and increasing insulation. In this project, a case study on lightning performance for an existing 275kV overhead transmission line in TNB system which tripped on numerous occasion due to lightning will be simulated. The lightning performance will be simulated using TFLASH software and result will be analyzed. The influence of parameters such as tower footing resistance, ground flash density and tower lightning arrestor on lightning performance of a selected transmission line will be analyzed and appropriate corrective measures will be discussed as well.