Digital Substation

Digital Substation is an engineering publication focused on IEC 61850 automation, protection systems, and digital grid intelligence.

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SmpSynch, holdover and the fate of complex protections at a digital substation

What IEC 61869-9 actually requires, and where the boundary lies between "still synchronized" and "no longer synchronized". The article unpacks the "2 → 1 → 0" misconception about SAMU/NCIT behavior on PTP loss, the link between clockClass, timeTraceable and SmpSynch, and how a complex protection function should react when one of its source streams loses synchronization.

Wireshark Capture Filters for IEC 61850 Traffic: A Digital Substation Engineer's Cheatsheet

A practical reference for capture filters in Wireshark when working with IEC 61850 traffic. Why a display filter is not enough on a digital substation (especially of the process-bus generation), how a capture filter differs from a display filter, how the BPF (Berkeley Packet Filter) syntax is structured, and ready-to-use filter recipes for GOOSE and SV — from selecting by EtherType and OUI to APPID and multicast addresses.

confRev: How Configuration Revisions Can Ruin Communications

8 out of 10 configurators fail to fully recognize SCD files. We analyze the confRev attribute in GOOSE and SV: what happens when the value does not match the expected one, and how this nearly derailed the commissioning of a real project with 43 IEDs.

Top-Down IEC 61850 Engineering: The Five-Step Process, Explained

Top-down IEC 61850 engineering — formalized in TR IEC 61850-90-30:2025 and TR IEC 61850-7-6 (Ed. 2) — moves specification errors from commissioning to the design phase, before a single IED is selected or procured. This article explains the mechanics of the five-step process: what each step produces, what files are exchanged, and why the sequence achieves outcomes the conventional bottom-up approach cannot.

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