Reliability of substation protection system based on IEC61850

Although the new technology of protection and automation system of substation based on IEC61850 standard has developed rapidly in China, reliability measures depending on this tech- nology need to be further researched. By taking advantage of convenient information sharing, two kinds of new schemes, shared backup protection unit (SBPU) and signal backup (SB), have been proposed to solve the failure problem of protective devices and current/voltage transducers respec- tively, and the working principle of these two schemes are also described. Furthermore, the key technologies of on-line diagnosis of protective devices' failure and on-line status diagnosis of op- tical or electronic current/voltage transducers to realize the two schemes are proposed.