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

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4.143
Date Code 20170814 Instruction Manual SEL-700G Relay
Protection and Logic Functions
Group Settings (SET Command)
Figure 4.99 Y-Side Over- and Underfrequency Element Logic
Rate-of-Change-of-
Frequency Protection
Frequency changes occur in power systems when there is an unbalance
between load and active power generated. Typically, generator control action
adjusts the generated active power and restores the frequency to nominal
value. Failure of such control action may lead to system instability unless
there is some remedial action, such as load shedding. You can use the rate-of-
change-of-frequency element to detect and initiate a remedial action. The
SEL-700G provides four rate-of-change-of-frequency elements. Table 4.41
shows the settings for this element.
Frequency Elements 1–6
Measured Frequency
Frequency Pickup Setting
Nominal Frequency Setting
Over- and Underfrequency Element Pickup Time Delay
Definite-Time Delayed Over- and Underfrequency Element Relay Word Bit
Relay Tracking Frequency FREQY
Over- and Underfrequency Element Torque Control n =
FREQY =
81YnTP =
FNOM =
81YnTD =
81YnT =
FREQTRKY =
81YTC =
FREQY
81YnTP
81YnT
81YnTP < FNOM
FREQTRKY
81YnTD
0
81YnTP ≥ FNOM
81YTC
FREQYOK
ZCFREQY
Table 4.41 Rate-of-Change-of-Frequency Settings (Sheet 1 of 2)
Setting Prompt Setting Range
Setting Name :=
Factory Default
a
ENABLE 81Rm N, 1–4 E81Rm := N
FREQm ROC LEVEL OFF, 0.10–15.00 Hz/s 81Rm1TP := OFF
FREQm ROC TREND INC, DEC, ABS 81Rm1TRN := ABS
FREQm ROC PU DLY 0.10–60.00 s 81Rm1TD := 1.00
FREQm ROC DO DLY 0.00–60.00 s 81Rm1DO := 0.00
FREQm ROC LEVEL OFF, 0.10–15.00 Hz/s 81Rm2TP := OFF
FREQm ROC TREND INC, DEC, ABS 81Rm2TRN := ABS
FREQm ROC PU DLY 0.10–60.00 s 81Rm2TD := 1.00
FREQm ROC DO DLY 0.00–60.00 s 81Rm2DO := 0.00
FREQm ROC LEVEL OFF, 0.10–15.00 Hz/s 81Rm3TP := OFF
FREQm ROC TREND INC, DEC, ABS 81Rm3TRN := ABS
FREQm ROC PU DLY 0.10–60.00 s 81Rm3TD := 1.00
FREQm ROC DO DLY 0.00–60.00 s 81Rm3DO := 0.00
FREQm ROC LEVEL OFF, 0.10–15.00 Hz/s 81Rm4TP := OFF
FREQm ROC TREND INC, DEC, ABS 81Rm4TRN := ABS