MULTI YEARS OBSERVATION OF LIGHTNING CHARACTERISTICS IN JAVA ISLAND AND ITS INFLUENCE ON OVERHEAD TRANSMISSION LINE PERFORMANCE Brian Bramantyo Satriaji Dwi Adiputro Harsono, Sriyono, Achmad Syerif Habibie, Putu Agus Aditya Pramana
PLN Research Institute
Abstract
Indonesia is known as a nation with high lightning activity. Therefore, evaluating data from the lightning detection system owned by PT PLN (Persero) is important to improve transmission line performance. Lightning data within 3 years period were analyzed to obtain various lightning characteristics. Further evaluation was conducted by overvoltage simulation upon the existing transmission line model to obtain lightning characteristic influence toward overhead transmission line performance. According to lightning data analysis for Java Island, it is found that: a) lightning event has an increasing trend, b) lightning intensity of a certain area is relatively consistent, and c) cumulative curve of the lightning event is different compared to IEEE or CIGRE curve. Based on the rolling sphere method and overvoltage simulation, the number of lightning which potentially triggers shielding failure was 16% but none of that lightning generates overvoltage above the insulator basic impulse insulation level. This number was reduced to 3% by providing zero degree shielding angle. Approximately 3% of lightning had the potential to trigger back flashover (BFO) with the assumption all tower footing resistance is 10 Ω. However, if the tower resistance is greater (i.e., 50 Ω), the number of lightning which potentially triggers BFO increases to 13%.
