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.