Scheme design and algorithm of substation centralized backup protection system

With the enlargement of the power grid, the setting and cooperation of traditional backup protection become more difficult. Based on advanced communication network and computer technology, a new substation backup protection configuration using substation area information is introduced in this paper. The structure and function of protection configuration is detailed expatiated at first, and the fault location process based on direction, overcurrent and distance is analyzed. According to the fault location, the tripping sequence of local protection and breaker failure protection, which have a good adaptability to different main connection and operation modes, are discussed. The proposed protection system not only provides the local protection and breaker failure protection for all the equipments in the substation but also shortens the operation time and avoids the complicated cooperation.