Impact of rural design, operating and restoration practices on the costs of service interruptions

Two common isolation-restoration procedures are evaluated in some detail to demonstrate that the isolation-restoration procedures adopted by a power utility depend on many variables and are usually unique to each utility´s distribution circuit configuration. Generalized conclusions may be in error without a detailed analysis of the isolation-restoration practices proposed. A zone branch methodology based on outage activity flow graphs is used to estimate the reliability levels of customers being served from different line sections of a sectionalized distribution trunk line. The results demonstrate that a customer´s reliability level depend on his location within a distribution circuit configuration and the type of isolation-restoration procedure adopted by a utility. A case study is presented to illustrate the impact of various isolation-restoration procedures on the cost of interruptions to a single rural customer