Analysis on Relay Protection Transition Technology and Outer Pre-path Selection Based on PBT

Abstract

To improve the performance of fault isolation and restoration in distribution grids, the feasibility of relay protection based on time-delay coordination in distribution systems is investigated. Design considerations of hybrid fault isolation and restoration combined by time-delay based relay protection and distribution automation system (DAS) are given. Firstly, the performance indexes of relay protection services are analyzed in four aspects: interface rate, time delay, bit error and channel. Secondly, based on the time delay formulas, the study is focused on the ending/receiving delay and the forwarding and switching delay about PBT transmitting relay protection services. Some commendations such as technology choice and routing configuration are given. Finally, how to choose linear protection switch is studied from the reliability standpoint.