GE UR Series L90, Instruction Manual, Page: 401 / 846

GE Multilin L90 Line Current Differential System 5-263
5 SETTINGS 5.7 CONTROL ELEMENTS
5
5.7.8 FREQUENCY RATE OF CHANGE
PATH: SETTINGS

CONTROL ELEMENTS

FREQUENCY RATE OF CHANGE

FREQUENCY RATE OF CHANGE 1(4)
Four (4) independent rate of change of frequency elements are available. The element responds to rate of change of fre-
quency with voltage, current and frequency supervision.
• FREQ RATE 1 TREND: This setting allows configuring the element to respond to increasing or decreasing frequency,
or to frequency change in either direction.
• FREQ RATE 1 PICKUP: This setting specifies an intended pickup threshold. For applications monitoring a
decreasing trend, set
FREQ RATE 1 TREND
to “Decreasing” and specify the pickup threshold accordingly. The operating
condition is: .
For applications monitoring an increasing trend, set
FREQ RATE 1 TREND
to “Increasing” and specify the pickup thresh-
old accordingly. The operating condition is: .
For applications monitoring rate of change of frequency in any direction set
FREQ RATE 1 TREND
to “Bi-Directional” and
specify the pickup threshold accordingly. The operating condition is:
• FREQ RATE 1 OV SUPV PICKUP: This setting defines minimum voltage level required for operation of the element.
The supervising function responds to the positive-sequence voltage. Overvoltage supervision should be used to pre-
vent operation under specific system conditions such as faults.
• FREQ RATE 1 OC SUPV PICKUP: This setting defines minimum current level required for operation of the element.
The supervising function responds to the positive-sequence current. Typical application includes load shedding. Set
the pickup threshold to zero if no overcurrent supervision is required.

FREQUENCY RATE

OF CHANGE 1
FREQ RATE 1
FUNCTION: Disabled
Range: Disabled, Enabled
MESSAGE
FREQ RATE 1 SOURCE:
SRC 1
Range: SRC 1, SRC 2, SRC 3, SRC 4
MESSAGE
FREQ RATE 1 TREND:
Decreasing
Range: Increasing, Decreasing, Bi-directional
MESSAGE
FREQ RATE 1 PICKUP:
0.50 Hz/sec
Range: 0.10 to 15.00 Hz/sec in steps of 0.01
MESSAGE
FREQ RATE 1 OV SUPV
PICKUP: 0.700 pu
Range: 0.100 to 3.000 pu in steps of 0.001
MESSAGE
FREQ RATE 1 OC SUPV
PICKUP: 0.200 pu
Range: 0.000 to 30.000 pu in steps of 0.001
MESSAGE
FREQ RATE 1 MIN
FREQUENCY: 45.00 Hz
Range: 20.00 to 80.00 Hz in steps of 0.01
MESSAGE
FREQ RATE 1 MAX
FREQUENCY: 65.00 Hz
Range: 20.00 to 80.00 Hz in steps of 0.01
MESSAGE
FREQ RATE 1 PICKUP
DELAY: 0.000 s
Range: 0 to 65.535 s in steps of 0.001
MESSAGE
FREQ RATE 1 RESET
DELAY: 0.000 s
Range: 0 to 65.535 s in steps of 0.001
MESSAGE
FREQ RATE 1 BLOCK:
Off
Range: FlexLogic operand
MESSAGE
FREQ RATE 1 TARGET:
Self-Reset
Range: Self-Reset, Latched, Disabled
MESSAGE
FREQ RATE 1 EVENTS:
Disabled
Range: Disabled, Enabled
df dt

df dt

–
Pickup

df dt

Pickup

abs df dt
  
Pickup
