Sampled data synchronization scheme for relay protection in smart substation

Synchronizing sampled data is a key factor to application reliability in relay protection. To eliminate the impact of the differences and the transmission latency caused by synchronization, and to identify data sampling time accurately and effectively, are critical to synchronize the bay level data with the process level in smart station. From the perspective of relay protection in smart substation applications, this article analyzes the issues which sampled data synchronization is facing in smart substation relay protection and elaborates the core idea, the advantages and disadvantages of sampled data synchronization technology in protection based on P2P communication mode, and sampled data sync mark technology in protection depended on external sync source. On the basis of current analysis and summarizes in the limitations of various synchronization schemes in engineering application, this article considers the networked application requirements in smart substation relay protection, and proposes a multi-interval data sampling synchronization scheme based on switch for data latency marking. The sampled data synchronization accuracy has been tested in the smart substation network simulation environment based on this technical scheme. The results show that the scheme meets the technical requirements of relay protection in sample data synchronization accuracy, which can realize the networked application of relay protection in smart substation.