Operation Principle - ABB Relion Technical Manual

Section 7
Impedance protection
Name Values (Range)
Z2Rev 0.005 - 3000.000
tZ2 0.000 - 60.000
OpModeZ3 Disable-Zone
Enable-Zone
Z3Fwd 0.005 - 3000.000
Z3Rev 0.005 - 3000.000
tZ3 0.000 - 60.000
Table 59: ZGCPDIS (21G) Group settings (advanced)
Name Values (Range)
LoadEnchModeZ3 Disabled
Enabled
Table 60: ZGCPDIS (21G) Non group settings (basic)
Name Values (Range)
GlobalBaseSel 1 - 6
7.2.6
7.2.6.1
7.2.6.2
162
Unit Step
ohm/p 0.001
s 0.001
- -
ohm/p 0.001
ohm/p 0.001
s 0.001
Unit Step
- -
Unit Step
- 1

Operation principle

Full scheme measurement
The execution of the different fault loops for phase-to-phase faults are executed in
parallel. The use of full scheme technique gives faster operation time compared to the
switched schemes that uses a pickup element to select correct voltage and current
depending on the fault type.
Impedance characteristic
The distance function consists of three zones. Each zone is self polarized offset mho
characteristics with reverse offset. The operating characteristic is in accordance to figure
67.
Default Description
30.000 Reverse reach setting for Zone 2
0.500 Time delay to operate for Zone 2
Disable-Zone Operation mode of Zone 3
30.000 Forward reach setting for Zone 3
30.000 Reverse reach setting for Zone 3
1.000 Time delay to operate for Zone 3
Default Description
Disabled Enable load enchroachment mode Zone 3
Default Description
1 Selection of one of the Global Base Value
groups
1MRK 502 048-UUS A
Technical manual