6.19
Date Code 20171021
Instruction Manual
SEL-421 Relay
Protection Applications Examples
500 kV Parallel Transmission Lines With Mutual Coupling Example
Power System Data
lists the power system data for this application example. Substitute the
values and parameters that correspond to your system when you set the relay
using this example as a guide.
Figure 6.3
500 kV Parallel Overhead Transmission Lines
Z1L1, Z0L1
Z1L2, Z0L2
Z1S, Z0S
Z1R, Z0R
Z0M
VY
VAZ
IX
IW
S (Moscow)
R (Pullman)
Line 2
Line 1
BK1B
BK1A
BUS 1
BUS 2
SEL-421
500 kV
500 kV
Table 6.7
System Data—500 kV Parallel Overhead Transmission Lines
Parameter
Value
Nominal system line-to-line voltage
500 kV
Nominal relay current
5 A secondary
Nominal frequency
60 Hz
Line length
75 miles
Line impedances:
Z
1L1
= Z
1L2
Z
0L1
= Z
0L2
44.78
87.6° primary
162.9
82.1° primary
Zero-sequence mutual coupling:
Z
0M
88.35
76.6° primary
Source S impedances:
Z
1S
= Z
0S
50
88° primary
Source R impedances:
Z
1R
= Z
0R
20
88° primary
PTR (Potential transformer ratio)
500 kV:111.11 V = 4500
CTR (Current transformer ratio)
2000:5 = 400
Phase rotation
ABC
Summary of Contents for SEL-421-4
Page 6: ...This page intentionally left blank ...
Page 14: ...This page intentionally left blank ...
Page 30: ...This page intentionally left blank ...
Page 104: ...This page intentionally left blank ...
Page 128: ...This page intentionally left blank ...
Page 536: ...This page intentionally left blank ...
Page 584: ...This page intentionally left blank ...
Page 616: ...This page intentionally left blank ...
Page 696: ...This page intentionally left blank ...
Page 750: ...This page intentionally left blank ...
Page 755: ...Instruction Manual PM400 01 NB SEL 400 Series Relays Instruction Manual 20171006 ...
Page 776: ...This page intentionally left blank ...
Page 932: ...This page intentionally left blank ...
Page 976: ...This page intentionally left blank ...
Page 1024: ...This page intentionally left blank ...
Page 1038: ...This page intentionally left blank ...
Page 1064: ...This page intentionally left blank ...
Page 1128: ...This page intentionally left blank ...
Page 1206: ...This page intentionally left blank ...
Page 1316: ...This page intentionally left blank ...
Page 1350: ...This page intentionally left blank ...
Page 1464: ...This page intentionally left blank ...
Page 1468: ...This page intentionally left blank ...
Page 1492: ...This page intentionally left blank ...
Page 1518: ...This page intentionally left blank ...