Parallel Redundancy Protocol (Prp) Solution - ABB REX640 Product Manual

REX640
Product version: 1
relays that have voltage-based protection or supervision
functions. The relay can receive up to four sampled value
streams and totally 16 measurements can be connected into
the protection relay application.
Relays with process bus based applications use IEEE 1588
edition 2 for high-accuracy time synchronization.
For redundant Ethernet communication in station bus, the relay
offers either two optical or two galvanic Ethernet network
interfaces. An optional third port with optical or galvanic
Ethernet network interface is also available. The relay also
provides an optional fiber-optic port for dedicated protection
communication which can be used for up to 50 km distances
depending on the selected fiber transceiver. The intended
teleprotection applications for this port are line differential and
line distance protection communication or binary signal
transfer. The optional third Ethernet interface provides
connectivity for any other Ethernet device to an IEC 61850
station bus inside a switchgear bay, for example connection of
a remote I/O. Ethernet network redundancy can be achieved
using the high-availability seamless redundancy (HSR) protocol
or the parallel redundancy protocol (PRP), or with a self-healing
ring using RSTP in the managed switches. Ethernet
GUID-AC53358A-5E83-4694-9BC2-29F5C4F4988C V2 EN
Figure 18.

Parallel redundancy protocol (PRP) solution

HSR applies the PRP principle of parallel operation to a single
ring. For each message sent, the node sends two frames, one
24
COM600
Ethernet switch
IEC 61850 PRP
redundancy can be applied to the Ethernet-based IEC 61850,
Modbus and DNP3 protocols.
The IEC 61850 standard specifies network redundancy which
improves the system availability for the substation
communication. The network redundancy is based on two
complementary protocols defined in the IEC 62439-3 standard:
PRP and HSR protocols. Both protocols are able to overcome a
failure of a link or switch with a zero switchover time. In both
protocols, each network node has two identical Ethernet ports
dedicated for one network connection.
The protocols rely on the duplication of all transmitted
information and provide a zero switchover time if the links or
switches fail, thus fulfilling all the stringent real-time
requirements of substation automation.
In PRP, each network node is attached to two independent
networks operated in parallel. The networks are completely
separated to ensure failure independence and can have
different topologies. As the networks operate in parallel, they
provide zero-time recovery and continuous checking of
redundancy to avoid failures.
Ethernet switch
through each port. Both frames circulate in opposite directions
over the ring. Every node forwards the frames it receives from
1MRS759144 A
SCADA
ABB