Power system reliability in terms of the system's operating states

In the first part of the paper, a review is given of the various schemes for classifying electric power system operating states as proposed in IEEE, EPRI and CIGRE publications and the International Electrotechnical Vocabulary. Next, distinction is made between system and state adequacy concepts and the adequacy criteria for the two are related for both deterministic and probabilistic adequacy evaluation methods. Finally, a discussion is given of how the system adequacy concept changes when the monopolistic way of operating power systems is replaced by competition on the energy market.