Typical Topology

State of the art substation automation systems use the

IEC61850 protocol for communication between IEDs (Intel

ligent Electronic Device), as well as from IEDs to the station

control computer. The IEC61850 protocol transmits different

signals, such as GOOSE messages (e.g. interlocking, trip, …),

Sampled Values and Client Server communication via an Eth

ernet network. Since these are mission critical services, the

data packet should reach its receivers with highest security

and minimum delay.

Communication networks applicable to substations based

on IEC61850 require a network with high availability. Accord

ingly, the requirements for the communication network include

beside IEC61850 specific features, fast network recovery time

in case of link failures and high MTBF figures.

As communication equipment has to work in harsh electro

magnetically polluted environments, mainly optical connec

tions are used, with distances to be covered of maximum a

few 100 meters.