Planning of the environmental friendly, technically and economically optimized electric power switchgear

Dependability of electric power switchgear shall be achieved through the efficient and optimal use of costeffective technical solutions and equipment of a long lifetime, with minimal needs for maintenance, aiming to maximum security of electricity supply during the entire planned switchgear lifetime of 40+ years. Previously established order of switchgear planning criteria: "functionality - technology - economy", with the ecology as secondary category, changed in: "functionality - ecology - economy - technology", what sets high ecological requirements upon the design. Additionally, the spatial conditions, connected to ecology, environment and site location, may be an inevitable factor that narrows the field of possible technical solutions, regardless of the cost of individual variants. Previously, availability of a switchyard was mostly achieved by deterministic approach, often resulting in conservative and unnecessarily expensive solutions, with still a number of weaknesses. From the earliest switchgear planning stages, an analysis and assessment of risks and the likelihood of their occurrence throughout its life cycle is required. Assessment of an acceptable risk level as a function of the switchgear importance is the foundation of the probabilistic approach to planning and plays a key role in managing the switchgear life cycle.