Customer outage cost evaluation in electric power systems

In order to relate investment costs to the resulting levels of supply reliability, it is required to quantify supply reliability in a monetary basis which can be achieved by calculating the expected interruption costs (EIC). Customer interruption costs (CIC) are used as substitute in the assessment of reliability worth in electric power systems. In order to determine an optimal and reliable level of customer service, reliability cost/worth is to be assessed by calculating the costs associated with different system configurations and assessing the corresponding reliability worth at the respective system load points. This paper presents the utilization of a practical radial distribution system of APCPDCL /APTRANSCO database in the development of individual sector and customer damage functions. Customer interruption costs due to failure in electrical energy supply depend on many factors. A composite customer damage function is created for combinations of all customer classes. The main objective of the paper is to assess reliability cost /worth indices of expected energy not supplied (EENS), expected cost of interruptions (ECOST) and interrupted energy assessment rate (IEAR) of a typical radial practical distribution system using a generalized analytical technique. The effects on customer interruption cost indices associated with alternate supply, protection devices, different switch fuse, and breaker are included in the analysis and also compared with the results of reinforcement of system by disconnect switch additions. The results presented in this paper will be useful for the electric power utilities, designers and planners in the decision-making stage.