Substation time synchronization in today and future architectures

The use of time synchronization is essential in different applications. Time synchronization accuracy depends on the method being used, the structure of the time network and the implementation of timeservers and IEDs. This paper discusses these topics and presents methods to help users to be able to check the quality of their devices. This paper is divided in three parts. First, the traditional time synchronization schemes are presented, comparing their features and the differences between each other. In the second part, PTP-based time synchronization is explained, considering aspects related to accuracy, redundancy and interoperability with legacy devices. The infrastructure requirements of the network are outlined. In the third part, the behavior of several GPS-based time references in the market is analyzed, and a methodology for time error checking is presented.