Including higher order outages and well-being considerations in subtransmission system reliability worth assessment

Abstract

Abstract This paper presents a method to evaluate the subtransmission system health (well-being) indices under a security-constrained well-being framework. The well-being framework is extended to include the societal worth of electric service reliability in 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 energy not supplied (EENS), expected cost of interruptions (ECOST), and interrupted energy assessment rate (IEAR), for both the healthy and at risk states in the well-being framework. Component outages of up to the third order with overlapping permanent, maintenance, and temporary failures, are included to arrive at more realisitic reliability worth indices. The concepts associated with extending the well-being framework to include higher order component outages and reliability worth parameters are illustrated by application to a small reliability test system designated RBTS.