Principles and Methods of Calculation of Probability of Loss of Generating Capacity

This paper presents the mathematical methods and their underlying principles for calculating the probability of outages of generating equipment by the loss of capacity method. An analysis is presented of observable data and their relation to derived quantities. Equations are developed for various types of generating units. The methods described are applicable to the evaluation of any number of interconnected systems. Formulas are included for probabilities of multiple full outages as well as combinations of full and partial outages. The mathematical methods are the basis of a computer program in use by the Commonwealth Edison Company for studies of generating capacity requirements.