An optimized design of substation-area protection in smart substation

This paper proposes a substation-area protection in smart substation to overcome the defects in conventional protection system. The protection can provide local backup protection for the whole substation with current differential principle. The current sampled values are obtained by process level Ethernet inside smart substation, also by wide-area Ethernet from adjacent substations. GOOSE messages of circuit breaker positions and primary protection tripping are used for protection function simultaneously, which will be transmitted by process level networks. A feasible scheme using Digital Signal Processor and Field Programmable Gate Array has been designed to realize the substation-area protection, which is in line with IEC 61850 standard.