Digital Substation is an engineering publication focused on IEC 61850 automation, protection systems, and digital grid intelligence.
From 20 May 2027, Coordinated Universal Time (UTC) will no longer be corrected with leap seconds. How the astronomical, atomic and coordinated time scales fit together, and what the end of leap seconds means for time synchronisation in a substation.
Precise time is a mandatory part of a modern substation: it is needed for event recording and oscillography, for Sampled Values, for phasor measurements and for other applications. But relying on a local receiver alone is becoming increasingly dangerous: jamming, interference and spoofing turn a single satellite source into a systemic risk. An architecture built around an ePRTC (enhanced Primary Reference Time Clock) in the telecom network and a TDG (Time Distribution Gateway) on site offers a heterogeneous approach: one precise time comes «from the sky», another «via the ground». The article — what ePRTC and TDG are, how they fit IEC 61850-9-3 PTP, and why a single redundant GNSS receiver is not enough.
Open-source world is rich with interesting projects. Today we present a project which offers a possibility of PTP implementation for further studies. Project is called PTPd (PTP daemon) and it offers implementation of the Precision Time protocol (PTP) as defined by the relevant IEEE 1588 standard. PTP Version 2 implements IEEE-1588-2008.