Ethernet Redundancy - ABB relion REF615 Applications Manual

Section 2
REF615 overview
2.7.2
32
Client A
Managed Ethernet switch
with RSTP support
GUID-283597AF-9F38-4FC7-B87A-73BFDA272D0F V3 EN
Figure 6: Self-healing Ethernet ring solution
The Ethernet ring solution supports the connection of up to 30
protection relays. If more than 30 protection relays are to be
connected, it is recommended that the network is split into several
rings with no more than 30 protection relays per ring. Each protection
relay has a 50-μs store-and-forward delay, and to fulfil the
performance requirements for fast horizontal communication, the
ring size is limited to 30 protection relays.

Ethernet redundancy

IEC 61850 specifies a network redundancy scheme that improves the system
availability for substation communication. It is based on two complementary
protocols defined in the IEC 62439-3:2012 standard: parallel redundancy protocol
PRP-1 and high-availability seamless redundancy HSR protocol. Both protocols rely
on the duplication of all transmitted information via two Ethernet ports for one logical
network connection. Therefore, both are able to overcome the failure of a link or
switch with a zero-switchover time, thus fulfilling the stringent real-time
requirements for the substation automation horizontal communication and time
synchronization.
PRP specifies that each device is connected in parallel to two local area networks.
HSR applies the PRP principle to rings and to the rings of rings to achieve cost-
effective redundancy. Thus, each device incorporates a switch element that forwards
frames from port to port. The HSR/PRP option is available for all 615 series protection
relays. However, RED615 supports this option only over fiber optics.
1MRS756378 S
Client B
Network A
Network B
Managed Ethernet switch
with RSTP support
REF615
Application Manual