Frequency Rate Of Change (Ansi 81R) - GE L90 Instruction Manual

CHAPTER 5: SETTINGS

5.8.14 Frequency rate of change (ANSI 81R)

SETTINGS  CONTROL ELEMENTS  FREQUENCY RATE OF CHANGE  FREQUENCY RATE OF CHANGE 1(4)
 FREQUENCY RATE
 OF CHANGE 1
The element responds to rate of change of frequency with voltage, current and frequency supervision.
— This setting configures the element to respond to increasing or decreasing frequency, or to frequency
FREQ RATE 1 TREND
change in either direction.
— This setting specifies an intended df/dt pickup threshold. For applications monitoring a decreasing
FREQ RATE 1 PICKUP
trend, set to "Decreasing" and specify the pickup threshold accordingly. The operating condition is:
FREQ RATE 1 TREND
-df/dt > Pickup.
For applications monitoring an increasing trend, set
accordingly. The operating condition is: df/dt > Pickup.
For applications monitoring rate of change of frequency in any direction set
specify the pickup threshold accordingly. The operating condition is: abs (df/dt) > Pickup.
— This setting defines the minimum voltage level required for operation of the element. The
FREQ RATE 1 OV SUPV PICKUP
supervising function responds to the positive-sequence voltage. Use overvoltage supervision to prevent operation under
specific system conditions, such as faults.
— This setting defines minimum current level required for operation of the element. The
FREQ RATE 1 OC SUPV PICKUP
supervising function responds to the positive-sequence current. Typical application includes load shedding. Set the pickup
threshold to 0.020 if no overcurrent supervision is required.
— This setting defines the minimum frequency level required for operation of the element. The
FREQ RATE 1 MIN FREQUENCY
setting can be used to effectively block the feature based on frequency. For example, if the intent is to monitor an
increasing trend but only if the frequency is already above certain level, set this setting to the required frequency level.
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
FREQ RATE 1

FUNCTION: Disabled
FREQ RATE 1 SOURCE:

SRC 1
FREQ RATE 1 TREND:

Increasing
FREQ RATE 1 PICKUP:

0.50 Hz/sec
FREQ RATE 1 OV SUPV

PICKUP: 0.700 pu
FREQ RATE 1 OC SUPV

PICKUP: 0.200 pu
FREQ RATE 1 MIN

FREQUENCY: 45.00 Hz
FREQ RATE 1 MAX

FREQUENCY: 65.00 Hz
FREQ RATE 1 PICKUP

DELAY: 0.000 s
FREQ RATE 1 RESET

DELAY: 0.000 s
FREQ RATE 1 BLOCK:

Off
FREQ RATE 1 TARGET:

Self-reset
FREQ RATE 1 EVENTS:

Disabled
FREQ RATE 1 TREND
Range: Disabled, Enabled
Range: SRC 1, SRC 2, SRC 3, SRC 4
Range: Increasing, Decreasing, Bi-directional
Range: 0.10 to 15.00 Hz/sec in steps of 0.01
Range: 0.100 to 3.000 pu in steps of 0.001
Range: 0.020 to 30.000 pu in steps of 0.001
Range: 20.00 to 80.00 Hz in steps of 0.01
Range: 20.00 to 80.00 Hz in steps of 0.01
Range: 0 to 65.535 s in steps of 0.001
Range: 0 to 65.535 s in steps of 0.001
Range: FlexLogic operand
Range: Self-reset, Latched, Disabled
Range: Disabled, Enabled
to "Increasing" and specify the pickup threshold
to "Bi-Directional" and
FREQ RATE 1 TREND
CONTROL ELEMENTS
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