Research on the Application of Smart Substation Area Protection

The outline of the national grid corporation’s relay protection technology is proposed to study the substation area protection based on the multi-interval information of substation to improve the backup protection performance. In this paper, in order to reduce the action time of the line distance II period of backup protection, the location of line fault is identified by using the sampling at each interval for substation area and protection action information. Meanwhile, in order to avoid the action of backup protection to expand the power outage, this paper studies the scheme of identifying line longitudinal faults accurately and then trip faults rapidly by using analog information for substation area combined with fault line phase current characteristics. This paper also discusses how to distinguish the fault of high impedance grounding and the current secondary circuit break by using substation area information.