Self-Healing Ethernet Ring - ABB RELION 620 Series Technical Manual

Section 2
620 series overview
2.5.1
54
performance requirements for tripping applications in distribution substations, as
defined by the IEC 61850 standard.
The protection relay can support five simultaneous clients. If PCM600 reserves one
client connection, only four client connections are left, for example, for IEC 61850
and Modbus.
All communication connectors, except for the front port connector, are placed on
integrated optional communication modules. The protection relay can be connected to
Ethernet-based communication systems via the RJ-45 connector (100Base-TX) or the
fiber-optic LC connector (100Base-FX).

Self-healing Ethernet ring

For the correct operation of self-healing loop topology, it is essential that the external
switches in the network support the RSTP protocol and that it is enabled in the
switches. Otherwise, connecting the loop topology can cause problems to the
network. The protection relay itself does not support link-down detection or RSTP.
The ring recovery process is based on the aging of the MAC addresses, and the link-
up/link-down events can cause temporary breaks in communication. For a better
performance of the self-healing loop, it is recommended that the external switch
furthest from the protection relay loop is assigned as the root switch (bridge priority
= 0) and the bridge priority increases towards the protection relay loop. The end links
of the protection relay loop can be attached to the same external switch or to two
adjacent external switches. A self-healing Ethernet ring requires a communication
module with at least two Ethernet interfaces for all protection relays.
Client A
Managed Ethernet switch
with RSTP support
GUID-283597AF-9F38-4FC7-B87A-73BFDA272D0F V3 EN
Figure 7: Self-healing Ethernet ring solution
1MRS757644 F
Client B
Network A
Network B
Managed Ethernet switch
with RSTP support
620 series
Technical Manual