Synchrocheck (Ansi 25) - GE N60 Instruction Manual

CONTROL ELEMENTS
The steady-state frequency of a power system is an indicator of the existing balance between the generated power and
the load. Whenever this balance is disrupted through the disconnection of significant load or the isolation of a part of the
system that has a surplus of generation, the effect is an increase in frequency. If the control systems of the generators do
not respond fast enough, to quickly ramp the turbine speed back to normal, the overspeed can lead to the turbine trip. The
overfrequency element can be used to control the turbine frequency ramp down at a generating location. This element
can also be used for feeder reclosing as part of the "after load shedding restoration."
The
OVERFREQ 1 SOURCE
The
OVERFREQ 1 PICKUP
5

5.8.7 Synchrocheck (ANSI 25)

SETTINGS  CONTROL ELEMENTS  SYNCHROCHECK  SYNCHROCHECK 1(6)
 SYNCHROCHECK 1

5-244
setting selects the source for the signal to be measured.
setting selects the level at which the overfrequency element is to pickup.
Figure 5-131: Overfrequency logic
SYNCHK1 FUNCTION:

Disabled
SYNCHK1 BLOCK:

Off
SYNCHK1 V1 SOURCE:

SRC 1
SYNCHK1 V2 SOURCE:

SRC 2
SYNCHK1 MAX VOLT

DIFF: 10000 V
SYNCHK1 MAX ANGLE

DIFF: 30°
SYNCHK1 MAX FREQ

DIFF: 1.00 Hz
N60 NETWORK STABILITY AND SYNCHROPHASOR MEASUREMENT SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
Range: Disabled, Enabled
Range: FlexLogic operand
Range: SRC 1, SRC 2, SRC 3, SRC 4, SRC 5, SRC 6
Range: SRC 1, SRC 2, SRC 3, SRC 4, SRC 5, SRC 6
Range: 0 to 400000 V in steps of 1
Range: 0 to 100° in steps of 1
Range: 0.00 to 2.00 Hz in steps of 0.01