ABB Typical Applications for AFS

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.

Today’s SCADA Systems for distribution networks often use

the IEC60870-5-104 protocol which is based on TCP/IP pro

tocol stack.

The communication network for SCADA systems, which has

to transmit real time and mission critical data, requires a

redundant network topology and enhanced traffic engineering

capabilities.

Besides SCADA data communication, distribution control

centers have additional requirements. It might be necessary to

provide a telephony system for operational purpose or chan

nels for Renewable Energy (e.g. wind farms).

Since MV networks might be restricted to city areas or larger

rural areas, the network design needs to be adapted as per

actual requirements. Accordingly communication networks

providing L2 Ethernet switching or L3 IP routing might be

required. For installation in MV substations extended tempera

ture range and immunity against EMC/EMI is required.

Distances to be overcome are typically in the range of a few

kilometers.

Today’s In-plant applications require enhanced Ethernet

communication functionality. Various services such as CCTV,

public address or access control systems require communica

tion with a central server or operator console.

In-plant communication refers to applications dealing with

security of the infrastructure and recovery to normal operation

after an incident. Therefore high availability of the communica

tion network and high performance features are required.

Some of the In-Plant applications require significant band

width (e.g. CCTV), therefore a proper planning of the network

for the initial and future expansion is needed.

To allow supervision and historical analysis it is necessary to

synchronize end devices (e.g. cameras) from a central time

server.