Effects Of Distribution System Reliability Index Distributions Upon Interruption Cost/Reliability Worth Estimates

Utilities increasingly are assessing system reliability from a cost/benefit point of view. Costs of interruptions are usually calculated to determine the benefit or worth of reliability. The paper reports on distribution system simulation studies which investigate the effect of interruption duration distributions and cost curve shapes on interruption cost estimates. It is found that use of the average outage duration to calculate interruption costs can, in a significant number of cases, result in large errors as compared with using the entire duration distribution. The use of the $/KWHR interruption cost coefficient form is compared with the duration specific $/KW form.