Strategy research of parallel gap in EHV overhead transmission lines

This article point out the new features of lightning faults by analyzing the overhead transmission lines affected by lightning. From the view of different lightning protection configurations, combining with the specific test, there are Lightning Proof EHV theoretical analysis and testing in different regions, different voltage levels and different levels of importance. And then, those tests draw some conclusions, such as, a parallel gap characteristics of different shapes, apply range and installation. Furthermore, the article discusses the longitudinal and lateral reasonable distance between the insulator strings parallel gap and lower electrodes deeply, and suggests that converted the “plugging” type to the “combining guidance” type, which can reduce transmission lightning fault line outage rate effectively, while maintaining the steady rate of lightning trip. At the end, it can enhance the transmission line lightning performance and improve the reliability of grid operation.