Analysis And Solution Scheme For Synchronization In Digital Substation

Problem of synchronization in the substation has been there, there are two main categories:First, within a single substation protection and monitoring devices need to synchronize the time; the second is associated substations need to synchronize the time, such as both sides of the differential protection devices taking current comparison pilot protection need to maintain accurate time synchronization. But with the promotion and application of electronic transformer and IEC61850 substation communication networks and systems standards, they bring about technological change for substation, but also introduced a new synchronization problem, such as MU access to signals from multiple electronic transformers, thus requiring the data is sampled at the same point in time mined. IEC61850 standard puts forward higher requirements about transmission time accuracy of all data in digital substation. Therefore, based current stage of development the smart grid, solution of the synchronization problem in digital substation has a very important practical significance and great value.First,digital substation related technologies and the existing problems were introduced, including concepts of the digital substation based on IEC61850, characteristics, network structure,etc, and network delay in process level of digital substation is analyzed.Based on this thesis of the characteristics of digital substation, the current various synchronization methods and their respective limitations in digital substation are discussed, a detailed study of a network synchronization technology-IEEE1588PTP conforming digital substation technology is done.Then the paper proposes two types of application schemes of IEEE1588 PTP in IEC61850 substations, which focus on single substation and multi-substation respectively. In the proposed schemes, the redundancy configuration scheme for Grandmaster clock using BeiDou Navigation Satellite System, Global Positioning System (GPS) and atomic clock is discussed. Synchronization solution of 9-2 samples is proposed.Finally, the research contents are summarized, and future research directions are also prospected.