The article presents an analysis of emergency situations on high- and extra-high-voltage overhead transmission lines (OTL) in the Republic of Kazakhstan and examines the factors that reduce the stability of the power system. Based on KEGOC JSC operational data for 2019–2023, the main causes of failures have been identified — long service life, climatic loads, and electrochemical corrosion of metallic structural elements of overhead transmission lines. Theoretical studies in the field of diagnostics and protection of 500 kV overhead transmission lines are reviewed, including monitoring and fault prediction methods. The necessity of developing an intelligent combined protection system integrated into the digital Smart Grid architecture is substantiated.

power engineering; high- and extra-high-voltage overhead transmission lines; emergency situations; diagnostics; system stability improvement.