Schweitzer Engineering Laboratories SEL-421-4 - Figure 5.60 Zone 1 Quadrilateral Ground-Distance Element Logic Diagram

5.78
SEL-421 Relay Instruction Manual Date Code 20171021
Protection Functions
Quadrilateral Ground-Distance Elements
XAG4 Zone 4 A-Phase quadrilateral ground-distance element
XBG4 Zone 4 B-Phase quadrilateral ground-distance element
XCG4 Zone 4 C-Phase quadrilateral ground-distance element
XAG5 Zone 5 A-Phase quadrilateral ground-distance element
XBG5 Zone 5 B-Phase quadrilateral ground-distance element
XCG5 Zone 5 C-Phase quadrilateral ground-distance element
Table 5.51 Quadrilateral Ground-Distance Elements Relay Word Bits
(Sheet 2 of 2)
Name Description
Figure 5.60 Zone 1 Quadrilateral Ground-Distance Element Logic Diagram
CVTBL
XAG1
IAL
IGL
0.1 • I
NOM
—RG1 < rAG1 < RG1
xAG1 < XG1
FSA
SPO
3PO
0SB1
67Q1T
ILOP
VPOLV
SERCA
B- and C-Phase Logic is Similar
xAG1 is the A-Phase-to-Ground Zone 1 Reactance Calculation
rAG1 is the A-Phase-to-Ground Zone 1 Resistance Calculation
+
—
+
—
XGPOL := IG
(setting)
32VE
32QE
32GF
XGPOL := I2
(setting)
ARESE = N
ENX2AG
Z50G1
(setting)