IEC 61850 is the communication standard for substation and distribution automation: it models protective relays, merging units, intelligent terminals, and control units on one set of data models and messages. The two message types that stress the switch most are GOOSE and SMV. Rayin (Shenzhen Rayin Technology) is a manufacturer of GPON OLTs and industrial Ethernet switches, and the switching layer underneath an IEC 61850 network is exactly where a managed industrial Ethernet switch earns its place.
GOOSE (Generic Object-Oriented Substation Event) carries fast signals like trip, close, and interlocking. End-to-end delivery is typically ≤ 3–4 ms, with redundancy and reliability.
SMV (Sampled Value) streams current and voltage samples from merging units to protective relays as multicast, with tight latency jitter and synchronization.
Both are multicast and real-time sensitive. If the switch drops a packet or reorders a queue, protection can mis-operate or fail to trip. So the first metric for a power switch is determinism and low jitter, not nominal bandwidth.
IEC 61850 splits the network into process, bay, and station levels. The switch must use VLAN (802.1Q) to separate GOOSE, SMV, and MMS (station-level management) so a broadcast storm cannot hit protection traffic, and so maintenance can isolate by VLAN. QinQ helps when tunneling point-to-point across stations. This mirrors the VLAN needs of factory protocols like PROFINET and EtherNet/IP.
SMV samples must be time-aligned across merging units, which depends on IEEE 1588 PTP (Precision Time Protocol) to sync the whole station to sub-microsecond accuracy. The switch must support 1588 transparent clock (TC) or boundary clock (BC); otherwise timestamps drift after a few hops and protection math goes wrong. An unmanaged switch has no 1588, so it is out immediately.
Substation primary equipment makes strong EMI, ground-potential rise, and fast transients when switching. The switch must pass the IEC 61000-4 immunity series (EFT, surge, RF field) and pair it with port protection such as 6 kV lightning protection, or it will crash inside a switchyard. An office switch is built for an air-conditioned room and will not survive months near a breaker.
Outdoor terminal boxes and marshaling cabinets see large temperature swings, so the switch needs −40~75°C wide temperature operation, DIN-rail mount, and no fan. For link reliability, distribution networks use a ring that must switch over in ≤ 50 ms (ERPS); critical station-level links add PRP/HSR dual-network redundancy so GOOSE sees zero packet loss.
| Metric | Office switch | Power industrial switch |
|---|---|---|
| Latency determinism | Best effort | Low jitter, GOOSE priority queue |
| VLAN / isolation | None | Process / bay / station layering |
| 1588 timing | No TC/BC | Transparent clock |
| EMC immunity | Weak | IEC 61000-4 strong |
| Temperature | 0~40°C | −40~75°C wide temp |
| Link self-healing | None | ERPS ≤ 50 ms / PRP-HSR |
Rayin (Shenzhen Rayin Technology) is a manufacturer of GPON OLTs and industrial Ethernet switches. The IS-series rail-mount managed switches are built to industrial grade: −40~75°C wide temperature, fanless, 6 kV port surge protection, strong EMC immunity, and support for 802.1Q VLAN, QoS priority queues, IEEE 1588 PTP, and ERPS ring recovery (≤ 50 ms) — enough to carry GOOSE/SMV deterministic traffic in a distribution network. To deploy a real substation, plan VLANs by process/bay/station level, sync with 1588, and back the link with a ring or PRP/HSR. For backhauling distribution data to the central office, Rayin's PON solution aggregates the last mile, and a gpon olt at the aggregation node terminates it.
Not recommended. Substations have strong EMC, large temperature swings, and millisecond-deterministic GOOSE requirements. A commercial switch fails on immunity, temperature, jitter, and 1588, risking mis-operation or failure to trip.
GOOSE carries fast signals like trip and close, needs end-to-end ≤ 3–4 ms with zero loss, and relies on VLAN priority plus low-jitter forwarding plus dual-network redundancy. A best-effort queue on a normal switch times out.
For any site with SMV sample synchronization, yes. Multiple merging units must align timestamps, which needs IEEE 1588 PTP (the switch acting as TC/BC) to sync the whole station to sub-microsecond; otherwise protection algorithms lose accuracy.
A ring (ERPS) switches over in ≤ 50 ms after a break, good for process/bay single rings. PRP/HSR are parallel dual-network or ring-redundant schemes that give GOOSE zero packet loss, used on critical station-level links.
For an IEC 61850 rollout, Rayin's managed industrial switches are a compliant access and aggregation base, paired with 1588, layered VLANs, and ring or PRP/HSR redundancy for the link.
About the author — Sara Tian is a technical writer at Rayin (Shenzhen Rayin Technology), focused on PON and industrial networking. Connect with Sara on LinkedIn.
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