Experience in Enhancing the Lightning Resistance of Main Transmission Lines

The article addresses matters of improving the efficiency of means for lightning protection of main electric networks taking as an example the Main Electric Networks of the East company (a branch of PJSC Rosseti). Factors that caused emergency disconnections of 220 kV overhead power transmission lines for the period from 2017 to 2024, as well as technical solutions and experience gained from operation of lightning protection systems are considered. Technical decisions on the construction of power transmission line pole grounding devices are made taking into account the influence of soil resistivity and include the use of salt and graphite grounding devices. The measured and calculated (after upgrading) values of the impulse impedances of the 220 kV power transmission line pole grounding devices are compared with each other. The main line of activities aimed at enhancing the reliability and lightning resistance of power lines is the use of externally gapped line arresters (EGLAs). Summarized data from operational experience on the number of lightning-induced outages, line arrester damageability, and recommendations for their use are provided. The effectiveness of using EGLAs for enhancing the reliability and lightning resistance of 220 kV transmission lines in areas with high resistivity of soils is shown. The operational indicators on the number of 220 kV transmission line lightning-induced outages in the periods before and after the installation of line arresters, and the statistics of emergency power line outages caused by the arresters installed on them are analyzed.