Extraction of Time-varying Failure Rates on power distribution system equipment considering failure modes and regional effects

Abstract

The purpose of this paper is to extract the Time-varying Failure Rates (TFR) on power distribution system equipment considering failure modes and regional effects. The extraction of accurate failure rates is important to both power utilities and customers because the rates are the most important factor on the probabilistic number and duration of interruption such as SAIDI. SAIFI, and CAIDI. First, we classified the failure modes into random and aging failures from the record of failure data of Korea Electric Power Corporation (KEPCO) in Korea for representing the constant failure rate by random failure and the increasing failure rate by aging failure. After the classification, the constant failure rate and the increasing failure rate are extracted by using exponential distribution function and the Weibull distribution function, respectively, in order to represent the hazard rate as the normal-operating stage and the aging stage of the bathtub curve. Further, the regional effects are considered by introduction of the regional factor representing regional characteristics such as mean load of the region and pollution level by soil. Finally, in the conclusions of this paper, the curves of the TFRs representing each region of industrial, commercial, remote, seaside, residential, and rural areas are presented. (C) 2010 Elsevier Ltd. All rights reserved.