Schweitzer Engineering Laboratories SEL-421-4 - Table 6.33 Automatically Calculated;Hidden Settings; Table 6.34 Relay Configuration (Group)

6.129
Date Code 20171021 Instruction Manual SEL-421 Relay
Protection Applications Examples
Out-of-Step Logic Application Examples
For those applications that allow the relay to operate for any internal and external
faults on a system during a power swing, set the 67Q1T element similar to the
67QUBF element:
50Q1P := same value as of 50QUBP. Level 1 Pickup (OFF, 0.25–100 Amps
sec.)
67Q1D := same value as of UBD. Level 1 Time Delay (0.000–16000 cycles)
67Q1TC := 1. Level 1 Torque Control (SELOGIC Equation)
For those applications that require the relay only trip for internal faults during a
power swing, disable the 67Q1T element by setting 50Q1P to OFF or E50Q = N.
This way, the Zone 1 distance elements are always blocked by the OSB logic.
The relay relies on Zone 2 overreaching elements together with the POTT
scheme to make high-speed trips for internal faults.
Example Completed
This completes the application example that describes setting the SEL-421 for
out-of-step blocking. Analyze your particular power system to determine the
appropriate settings for your application.
Relay Settings
Table 6.33 lists the settings that the relay automatically calculates and hides when
you set EADVS to N and EOOST to N.
Table 6.34 and Table 6 .35 list the protective relay settings available in this example.
Table 6.33 Automatically Calculated/Hidden Settings
Setting Prompt Default Setting
X1B7 Zone 7 Reactance—Bottom (–0.05 to –140  secondary) X1B7 = –X1T7
X1B6 Zone 6 Reactance—Bottom (–0.05 to –140  secondary) X1B6 = –X1T6
R1L7 Zone 7 Resistance—Left (–0.05 to –140  secondary) R1L7 = –R1R7
R1L6 Zone 6 Resistance—Left (–0.05 to –140  secondary) R1L6 = –R1R6
OSTD Out-of-Step Trip Delay (0.500–8000 cycles) 0.500
50ABCP Positive-Sequence Current Supervision (1.00–100 A secondary) 50ABCP = 0.2 • I
NOM
50QUBP Negative-Sequence Current Supervision
(OFF, 0.50–100 A secondary)
OFF
UBD Negative-Sequence Current Unblock Delay
(0.500–120 cycles)
0.500
UBOSBF Out-of-Step Angle Unblock Rate (1–10) 4
Table 6.34 Relay Configuration (Group)
Setting Prompt Entry
EOOS Out-of-Step (Y, Y1, N) Y
EADVS Advanced Settings (Y, N) N