Methodology for Overhead Conductor Replacement Considering Operational Stress and Aging Characteristics

This paper presents a novel methodology for the prioritization of overhead conductor replacement considering operational stress and aging characteristics. The time sequential Monte Carlo technique is used to assess the reliability of a distribution network over a planning period. To incorporate the influence of high operating temperatures and aging characteristics into the reliability assessment, up-times of aging conductors are sampled using the interval-by-interval method, Arrhenius life-temperature relationship, and thermal model IEEE 738-2006. Aging conductors are ranked for replacement based on the financial losses caused by their failures throughout the planning period. The methodology was tested using the IEEE 33-bus distribution network model. Results indicate that failures of aging conductors affect significantly system reliability indices. Furthermore, it was determined that financial losses of aging conductors depend on the conductor location and network's protection scheme. The proposed methodology may help utilities improve both asset replacement plans and system reliability.