Towards Understanding and Embracing EGLA Technology: An In-Depth Review and Future Outlook

This paper deals with the Externally-Gapped Line Arrester (EGLA) technology as the most effective and suitable Line Surge Arrester (LSA) design to meet the requirements of overhead lines. While the use of EGLAs is not yet fully understood and adopted by the electricity supply industry, we strive to provide experience feedback on the long term. Indeed, the example of Japan is very relevant and deserves to be communicated more widely. Although the technical superiority of EGLA is emphasized in this paper, the operating principles and differences between EGLA and Non-Gapped Line Arrester (NGLA) are not compared here, this has been covered in various other technical papers. The facts about adoption in the precursor countries are sufficiently striking to call into question certain practices today. We consider that the basic principles of lightning outages mitigation are understood by the reader. Multiple publications exist to demonstrate the technical-economic advantages of LSAs in reducing lightning induced outages. The idea of this document is to have a retrospective vision, to analyze the EGLA technology and the use of today and specially to project ourselves in the years to come to understand how the EGLA can influence the power transmission industry and facilitate the energy transition. We have noticed a lack of communication in the last 30 years about this kind of application, so we want to make it possible for everyone to understand.