Different approaches to reliability as applied to the generation — transmission system and its components

Abstract The generation-transmission system may be regarded as a hierarchical organization in which the various interconnected components form more or less complex subsystems (nuclear, thermal and hydro units, substations, transmission lines, etc). Each component has a share in the reliability of the electric power system. How should their reliability and that of the system be studied? The objective of the paper is to describe the current state of the art for the methods and models used at Electricite de France. The main stress is on probabilistic studies of, in particular nuclear unit maintenance and repair operation outages, 400 kV network planning, substation reliability and nuclear power plant safety. Future work will be based on a synergy of the methods used in these various areas.