Reliability Evaluation of IEC 61850 Process Bus Architecture for Protection Function

Abstract

The complex redundancy architecture of IEC 61850 process bus brings difficulties to the reliability analysis of digital protection system. An approximation method can be considered for the reliability analysis of protection system. This article analyses the weakness of conventional reliability approximation algorithms in the aspects of calculation accuracy, and then presents a disjoint path set (DPS)-based approximation method which is simple and practical. The sampled value (SV) and generic-object-oriented substation event (GOOSE) are adopted as the basic function to build the protection function model. The digital protection system is expressed as a single-input multiple-output (SIMO) model which is more suitable for describing distributed protection function. A case of the line protection in a 3/2 connection system is analyzed to demonstrate the validity of the proposed method and model.