Effects of adverse weather conditions and higher order outages on customer interruption costs in electric subtransmission systems

Abstract

Evaluation of the costs and benefits of various investment options is becoming increasingly popular with electric power utilities. In order to incorporate economics into the reliability cost-benefit equation, it is imperative that the cost of attaining a level of reliability be compared with the worth or benefit derived by society from that level of reliability. This paper pertains to the assessment of the value (worth) of reliability in an electric subtransmission system. Customer outage data collected from customer survey methods are used in conjunction with system reliability indices to predict customer interruption costs that are representative of reliability worth. The component failure modes recognized in this paper are active, permanent, temporary, maintenance and adverse-weather-related outages. The impacts on the customer interruption cost of all such failure modes are illustrated by application to a test system which is sufficiently large that practical factors can be realistically modelled and assessed and also sufficiently small that the effect of sensitivity studies can be easily identified. The basic thrust is on identifying the impacts of higher order component outages and weather-related outages on system reliability and therefore on the perceived worth, that is, on the cost of unreliability.