Schweitzer Engineering Laboratories SEL-311C - Ground Distance Elements; Table 3.3 Ground Distance Elements Settings

3.10
SEL-311C Relay Instruction Manual Date Code 20060320
Distance, Out-of-Step, Overcurrent, Voltage, Synchronism Check, and Frequency Elements
Distance Elements
Ground Distance
Elements
The SEL-311C has four independent zones of mho and quadrilateral ground
distance protection. All zones are independently set. Zones 1 and 2 are
forward direction only, and Zones 3 and 4 can be set in either a forward or
reverse direction. The mho ground distance elements use positive-sequence
voltage polarization for security and to create an expanded mho characteristic.
The directional polarizing quantity for the reactance portion of the
quadrilateral ground distance element may be selected from negative-
sequence current or zero-sequence current if Advanced Settings are enabled
(Setting EADVS = Y).
Table 3.3 Ground Distance Elements Settings (Sheet 1 of 2)
Impedance Reach (Zones 1–4)
Enable Setting for
Mho Ground (E21MG):
Quadrilateral Ground (E21XG):
OFF, 1–4
OFF, 1–4
Settings range for
Mho elements (Z1MG–Z4MG):
OFF, 0.05 to 64 Ω sec, 0.01 Ω steps (5 A nominal)
OFF, 0.25 to 320 Ω sec, 0.01 Ω steps (1 A nominal)
Settings range for Quadrilateral
Reactance elements (XG1–XG4):
OFF, 0.05 to 64 Ω sec, 0.01 Ω steps (5 A nominal)
OFF, 0.25 to 320 Ω sec, 0.01 Ω steps (1 A nominal)
Settings range for Quadrilateral
Resistance elements (RG1–RG4):
OFF, 0.05 to 50 Ω sec, 0.01 Ω steps (5 A nominal)
OFF, 0.25 to 250 Ω sec, 0.01 Ω steps (1 A nominal)
Minimum sensitivity is controlled by the pickup of the
supervising phase and residual overcurrent elements for each zone.
Accuracy: ±5% of setting at line angle for 30 ≤ SIR ≤ 60
±3% of setting at line angle for SIR < 30
Transient Overreach: <5% of setting plus steady-state accuracy
Phase and Residual Current Fault Detectors (Zones 1-4)
Setting Range for
Phase and Residual Current
Fault Detectors (50L1–50L4
and 50GZ1–50GZ4)
a
:
0.50–100.00 A secondary, 0.01 A steps
(5 A nominal)
0.10–20.00 A secondary, 0.01 A steps
(1 A nominal)
Accuracy: ±0.05 A and ±3% of setting (5 A nominal)
±0.01 A and ± 3% of setting (1 A nominal)
Transient Overreach: <5% of pickup
Max. Operating Time: See pickup and reset time curves in Figure 3.20 and Figure 3.21.
Other Settings
Settings range for
zero-sequence compensation (ZSC)
factor magnitude
k0M1 and k0M =
0.000–6.000 unitless (Zone 1)
0.000–6.000 unitless (Zone 2, 3, 4 advanced setting hidden
and set to k0M1 when EADVS = N)
Settings range for zero-sequence
compensation (ZSC) factor angle
k0A1 = and k0A =
–180.0 to +180.0 degrees (Zone 1)
–180.0 to +180.0 degrees (Zones 2, 3, and 4 advanced setting hidden and set
to k0A1 when EADVS = N)
where k0M1 k0A1∠
Z0MAG Z0ANG∠()Z1MAG Z1ANG∠()–
3 Z1MAG Z1ANG∠()•
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