Ethernet Redundancy - ABB RELION REX640 Technical Manual

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3.2.3

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 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 most demanding real-time
application requirements for the substation automation.
Ethernet network redundancy can be achieved using HSR or PRP and it is applied to
all services using the Ethernet/TCP network.
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.
PRP
Each PRP node, called a double attached node with PRP (DAN), is attached to
two independent LANs operated in parallel. These parallel networks in PRP are
called LAN A and LAN B. The networks are completely separated to ensure failure
independence, and they can have different topologies. Both networks operate in
parallel, thus providing zero-time recovery and continuous checking of redundancy
to avoid communication failures. Non-PRP nodes, called single attached nodes
(SANs), are either attached to one network only (and can therefore communicate
only with DANs and SANs attached to the same network), or are attached through a
redundancy box, a device that behaves like a DAN.
REX640
Technical Manual
IEC 62439-3:2012 cancels and replaces the first edition published in 2010.
These standard versions are also referred to as IEC 62439-3 Edition 1 and
IEC 62439-3 Edition 2. The protection relay supports IEC 62439-3:2016
(Edition 3) and IEC 62439-3:2012 and it is not compatible with IEC
62439-3:2010.
Basic functions
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