Implementation of a High-Speed Distribution Network Reconfiguration Scheme

Traditionally, when a permanent fault occurs on a radial distribution line, all load located downline from the protecting device is lost until sectionalizing and network reconfiguration can be done either locally, by personnel responding to the event, or remotely, by a dispatcher (if SCADA is present). In many instances, a substantial amount of load may be lost and a significant number of customers may be impacted until sectionalizing is performed. With much emphasis now being placed on reliability, there is a need to automate sectionalizing and network reconfiguration to speed up service restoration to as many customers as possible, in order to minimize the impact of a fault. Recently Coweta-Fayette EMC, an electric cooperative in Newnan, Georgia, near Atlanta, implemented a high-speed automatic network reconfiguration scheme on a distribution circuit to quickly restore service to unfaulted line sections de-energized by the clearing of a permanent fault. The scheme uses intelligent microprocessor recloser controls and a communications channel between adjacent reclosers to quickly reconfigure the distribution network following a fault. This paper examines the implementation of the reconfiguration scheme by the utility. Specific settings and operational details of the scheme are given. Additionally, a review of the operational history highlights the impact the scheme has had on the reliability of the utility´s distribution network