Composite power system adequacy assessment in terms of well-being

Abstract

This paper presents a system well-being evaluation method that divides the composite power system operating condition into several states depending on the level to which the adequacy and security constraints are satisfied. Conventional composite system reliability indices typically do not reflect the ability of the system to withstand, without resulting in load curtailment or other violations, the abrupt loss of system components. The well-being evaluation method provides an extra index for system planners or designers to decide whether or not the power system is capable, based on the deterministic criteria, to withstand unplanned outages of system components without violation of specified constraints. The well-being indices, which are the probabilities of the system being in the healthy, marginal and at risk states, provide this important and intuitively interpretable information for system planning and operations. Studies on two test systems were done to examine the effect of load levels, system component removal and addition on the well-being indices. The bus well-being indices for selected buses of the two test systems were also calculated and compared with the system well-being indices.