ABB Relion 650 Series Technical Manual page 82

Section 5
Impedance protection
Table 18: ZQDPDIS (21) Non group settings (basic)
Name Values (Range)
GlobalBaseSel 1 - 6
5.1.6 Operation principle
5.1.6.1 Full scheme measurement
The execution of the different fault loops within the IED are of full scheme type, which means that
each fault loop for phase-to-ground faults and phase-to-phase faults for forward and reverse
faults are executed in parallel.
Figure 32
zones.
A-G
A-G
A-G
A-G
A-G
ANSI05000458 V1 EN-US
Figure 32: The different measuring loops at phase-to-ground fault and phase-to-phase
The use of full scheme technique gives faster operation time compared to switched schemes
which mostly uses a pickup of an overreaching element to select correct voltages and current
depending on fault type. Each distance protection zone performs like one independent distance
protection IED with six measuring elements.
5.1.6.2 Impedance characteristic
The distance measuring zone includes six impedance measuring loops; three intended for phase-
to-ground faults, and three intended for phase-to-phase as well as, three-phase faults.
The distance measuring zone will essentially operate according to the non-directional impedance
characteristics presented in figure
illustrated with the full loop reach while the phase-to-phase characteristic presents the per phase
reach.
76
Unit
-
presents an outline of the different measuring loops for the five, impedance-measuring
B-G C-G
B-G C-G
B-G C-G
B-G C-G
B-G C-G
fault.
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Step Default
1 1
A-B B-C
A-B B-C
A-B B-C
A-B B-C
A-B B-C
33 and figure 34. The phase-to-ground characteristic is
Description
Selection of one of the Global Base Value
groups
Zone 1
C-A
Zone 2
C-A
Zone 3
C-A
Zone 4
C-A
Zone 5
C-A
en05000458_ansi.vsd
Line distance protection REL650
1MRK 506 326-UUS B
M16923-92 v4
M16923-100 v6
Technical manual