Probabilistic Reliability Analysis in the Norwegian Transmission System

This paper gives a detailed account of current practices within probabilistic long-term reliability assessment at the Norwegian Transmission System Operator (TSO), Statnett. The core of recent advancements, a comprehensive self-developed Monte Carlo based simulation tool for component failures, is briefly presented along with some comments on the development process. Practical examples included in the paper demonstrates how the simulation tool aid power system analysts toward a deeper, more fundamental insight to power system reliability previously unavailable. In addition, a method to quantify the value of reliability through the probabilistic reliability index Cost of Energy Not Served (CENS) is presented, providing a valuable contribution to improved socio-economic cost benefit analysis in power system planning. The big potential of probabilistic reliability assessment within many TSO related tasks motivates the continued development of the simulation tool and associated methods for reliability analysis. Selected plans at Statnett are therefore also included in this paper.