Impacts of adverse weather on reliability worth indices in subtransmission systems using deterministic as well as probabilistic criteria

Value-based reliability (VBR) planning approaches seek to assist utilities in establishing a balance between the cost of improving service reliability and quality, and the economic benefits that these proposed improvements bring to customers has become an integral part of the electricity supply industry. This paper is an application of the VBR concept in system planning. The main objective of this paper is to discuss the impacts of adverse-weather related outages on customer interruption costs in a reliability well-being assessment of subtransmission systems. System well-being is defined in terms of the three system states of healthy, marginal, and at risk, thus combining the deterministic and probabilistic approaches into a single framework. The paper discusses the determination of reliability worth indices of expected cost of interruptions (ECOST) and interrupted energy assessment rate (IEAR), for both the healthy and at risk states in the well-being framework.