Outages of transmission lines in substations: Transmission Operations Novi Sad caused by flashovers on insulator strings and busbars

This paper analyses the causes of outages in transmission substations, with a particular focus on flashovers occurring on insulator strings and busbars in facilities operating at voltage levels of 110 kV and 220 kV. Special attention is given to flashovers on insulators, recognised as one of the most frequent causes of interruptions in the operation of electrical power systems. The analysis is based on data collected between 2000 and 2015 at substations managed by the public enterprise Elektromreža Srbije (EMS), Transmission Operations Novi Sad, with the provided justification of the relevance of this period up to the present day. The research examines the temporal distribution of outages and the influence of climatic factors such as humidity and morning dew on the degradation of insulation properties of the equipment. The objective of the study is to reduce the number of outages of this type, thereby enhancing the reliability of the transmission system and reducing the duration of power interruptions. The findings can serve as a foundation for optimising insulator selection and for defining further technical measures aimed at improving the performance and safety of the electrical transmission network.