Schweitzer Engineering Laboratories SEL-700G Series, Инструкция по эксплуатации

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4.144
SEL-700G Relay Instruction Manual Date Code 20170814
Protection and Logic Functions
Group Settings (SET Command)
Use the E81R setting to enable the number of elements you want.
Figure 4.100 shows the general element logic that applies to both X and Y
sides. The SEL-700G measures frequency (MF1) and second frequency
(MF2) after a time window (dt) determined by Trip Level setting (81RmnTP)
to compute rate-of-change of frequency. The element uses an hysteresis
(dropout/pickup ratio of 95%) to prevent chattering. Table 4.42 shows the time
windows for different trip level settings.
m = X or Y; n = 1–4
Figure 4.100 81R Frequency Rate-of-Change Scheme Logic
FREQm ROC PU DLY 0.10–60.00 s 81Rm4TD := 1.00
FREQm ROC DO DLY 0.00–60.00 s 81Rm4DO := 0.00
FREQm ROC VSUPER OFF, 12.5–300.0 V 81RmVSUP := OFF
FREQm ROC TRQCTRL SEL
OGIC
81RmTC := 1
a
m = X or Y.
Table 4.41 Rate-of-Change-of-Frequency Settings (Sheet 2 of 2)
Setting Prompt Setting Range
Setting Name :=
Factory Default
a
Setting 81RmnTp
where m = X, Y and
n = 1–4
FREQm
81RmnTRN = INC
81RmnTRN = ABS
81RmnTRN = DEC
MF2 > FNOM
MF2 < FNOM
81RmTC
81RmVSUP = OFF
V1m
81RmVSUP
PU = 81RmnTD
DO = 81RmnDO
3 SEC
0
(MF2-MF1)/dt
PU
DO
81RmnT
Relay
Word
Bit
95%
95%
95%
ABS
*(-1)
0 if m = X
FREQYOK if m = Y
FREQTRKm
Table 4.42 Time Window Versus 81RmnTP Setting
a
(Sheet 1 of 2)
81RmnTP Setting (Hz/s) Time-Window (Cycles)
15.00–2.33 3
2.32–1.17 6
1.16–0.78 9
0.77–0.58 12
0.57–0.47 15
0.46–0.38 18
0.37–0.33 21
0.32–0.29 24