Preliminary Exploration of Fault Diagnosis Strategy for Overhead Transmission Lines in DC Power Grid

HVDC transmission lines are facing unprecedented challenges due to its unique operating characteristics, complex operating mechanism, and possible extreme weather and harsh environment. The limitations of traditional physical model analysis methods, insufficient control and protection data, and difficulty in extracting fault features results in low accuracy and inefficiency in fault diagnosis, making it challenging to satisfy the demands of new power systems for precise fault identification and swift response. Therefore, this article conducted research on power grid fault diagnosis, based on actual data and simulation of overhead lines, exploring the theoretical methods of common fault diagnosis techniques, and proposing indicators and technical routes for judging four types of fault situations: lightning strikes, ice disasters, windage yaw, and dancing. Taking lightning strikes as an example, the voltage changes of lightning current acting on typical DC lines are simulated and analyzed in PSCAD simulation software, which provides a reference for the fault diagnosis of transmission lines in DC power grid.