Introduction; Internal Teleprotection - ABB ETL600 Instruction Manual

ETL600
•
SCADA applications using telegram based protocols for
communication between master and RTUs:
•
•
•
Maximum allowed deviation from nominal data rate for any application
is ± 400 ppm.
For parameters that are configurable for V.24 interfaces with the
different applications, refer to section 5.3.5.3.3.
The physical interface is a Sub-D 9 pole connector with pinout
compliant to EIA/TIA 574 for TD, RD, RTS, CTS, DCD and SGND
signals. For detailed pinout information refer to section 6.6.3.3.2.
3.6.

Internal Teleprotection

3.6.1.

Introduction

The sizes, complexity and power ratings of high voltage networks
emphasize the need for highly reliable protection systems. Protection
is based on information derived from the power system at one or more
points, and fast selective protection applied to circuits with
geographically separated terminals, such as cables and overhead
lines, requires information interchange between these terminals.
Teleprotection equipment (TPE) transmit the tripping signals from the
protection equipment in high voltage grids of electricity utilities,
between power system control centers, power stations and sub-
stations. Teleprotection links using power line carrier (PLC) channels
are the most economical way of performing all the tasks associated
with transmitting tripping signals. In case of power line carrier as a
telecom link the requirements are especially high since the protection
commands are transferred within faulty sections of the power grid.
Since any communication system is subject to interference and noise
of various forms, the performance of a teleprotection equipment is
commonly described in terms of security, dependability and
transmission time; further characteristics are the bandwidth of analog
equipment and the signaling rate of digital equipment. Interference and
noise on the communication link must neither simulate a command at
the receiving end when no command signal was transmitted (security),
nor impair the ability to convey commands correctly and promptly
(dependability).
Security, dependability, transmission time and bandwidth (or signaling
rate) are interrelated and interchangeable parameters. High security
and high dependability together with short transmission time and
narrow bandwidth are therefore conflicting requirements, but the
Structure and Function
1KHW001489-EN
ABB proprietary protocol RP570/RP571 based on IEC60870-1-
5 FT1.2 with 8 data bits, 1 stop bit and even parity;
ABB proprietary implementation of asynchronous DNP3.0
based on IEC60870-1-5 FT3 with 8 data bits, 1 stop bit and no
parity.
Maximum supported telegram length for these two protocols is
255 characters.
ABB Switzerland Ltd
November 2005 3-53