18.3
IEC/UCA 61850-9-2LE communication protocol
SEMOD172279 v3
18.3.1
Introduction
SEMOD166571-1 v2
SEMOD166590-5 v6
Every IED can be provided with communication interfaces enabling it to connect to
the process buses in order to get data from analog data acquisition units close to the
process (primary apparatus), commonly known as Merging Units (MU). The
protocol used in this case is the IEC/UCA 61850-9-2LE communication protocol.
The IEC/UCA 61850-9-2LE standard does not specify the quality of the sampled
values. Thus, the accuracy of the current and voltage inputs to the merging unit and
the inaccuracy added by the merging unit must be coordinated with the requirement
for the actual type of protection function.
Factors influencing the accuracy of the sampled values from the merging unit are,
for example, anti aliasing filters, frequency range, step response, truncating, A/D
conversion inaccuracy, time tagging accuracy etc.
In principle, the accuracy of the current and voltage transformers, together with the
merging unit, will have the same quality as the direct input of currents and
voltages.
The process bus physical layout can be arranged in several ways, described in
Annex B of the standard, depending on what are the needs for sampled data in a
substation.
1MRK 505 393-UEN B
Section 18
Station communication
Line differential protection RED650 2.2 IEC
365
Application manual
Summary of Contents for RED650
Page 1: ...RELION 650 SERIES Line differential protection RED650 Version 2 2 Application manual ...
Page 2: ......
Page 22: ...16 ...
Page 32: ...26 ...
Page 82: ...76 ...
Page 112: ...106 ...
Page 152: ...146 ...
Page 208: ...202 ...
Page 214: ...208 ...
Page 282: ...276 ...
Page 356: ...350 ...
Page 404: ...398 ...
Page 408: ...402 ...
Page 442: ...436 ...
Page 452: ...446 ...
Page 453: ...447 ...