Schweitzer Engineering Laboratories SEL-311C - Figure 3.30 Synchronism Check Voltage Window and Slip Frequency Elements; Figure 3.31 Synchronism Check Elements

3.46
SEL-311C Relay Instruction Manual Date Code 20060320
Distance, Out-of-Step, Overcurrent, Voltage, Synchronism Check, and Frequency Elements
Synchronism Check Elements
q See bottom of Figure 3.31; w to Figure 3.31.
Figure 3.30 Synchronism Check Voltage Window and Slip Frequency Elements
w
low threshold
high threshold
low threshold
high threshold
V
S
within "healthy
voltage" window
voltage" window
to Angle
Difference Calculator (see q)
absolute
value
Setting
SEL
OGIC
Setting
V
P
within "healthy
Max. Slip Freq.
Block Synchronism Check
Slip
Frequency
Slip Frequency
Element
CYC
3
0
BSYNCH
Bits
Word
Relay
Setting
25SF
V
S
V
P
SF
59VS
59VP
25VHI
-
+
Calculator
Frequency
Slip
Enable
—
+
+
—
+
—
—
+
25VLO
Setting
—
+
—
voltage" window
V
A
within "healthy
low threshold
59VA
+
high threshold
V
A
[select from V
A
, V
B
, V
C
or V
AB
, V
BC
, V
CA
with
setting SYNCP]