GE L30 Instruction Manual page 430

CONTROL ELEMENTS
5
The synchronism check function supervises the paralleling of two parts of a system that are to be joined by the closure of
a circuit breaker. The synchrocheck elements are typically used at locations where the two parts of the system are
interconnected through at least one other point in the system.
Synchrocheck verifies that the voltages (V1 and V2) on the two sides of the supervised circuit breaker are within set limits
of magnitude, angle, and frequency differences. The time that the two voltages remain within the admissible angle
difference is determined by the setting of the phase angle difference ΔΦ and the frequency difference ΔF (slip frequency). It
can be defined as the time it takes the voltage phasor V1 or V2 to traverse an angle equal to 2 × ΔΦ at a frequency equal
to the frequency difference ΔF. This time is calculated by:
where
ΔΦ is phase angle difference in degrees
ΔF is frequency difference in Hz
If one or both sources are de-energized, the synchrocheck programming can allow for closing of the circuit breaker using
undervoltage control to bypass the synchrocheck measurements (dead source function).
SYNCHK1 V1 SOURCE
SYNCHK1 V2 SOURCE
5-252
SYNCHK1 MAX FREQ

HYSTERESIS: 0.06 Hz
SYNCHK1 SYNC CLOSE:

Off
SYNCHK1 S-CLS MAX

dF: 0.50 Hz
SYNCHK1 S-CLS MIN

dF: 0.10 Hz
SYNCHK1 S-CLS BRK

TIME: 0.035 s
SYNCHK1 V2 MAG CORR

FACTOR: 1.00
SYNCHK1 V2 ANGLE

SHIFT: 0
SYNCHK1 DEAD SOURCE

SELECT: LV1 and DV2
SYNCHK1 DEAD V1

MAX VOLT: 0.30 pu
SYNCHK1 DEAD V2

MAX VOLT: 0.30 pu
SYNCHK1 LIVE V1

MIN VOLT: 0.70 pu
SYNCHK1 LIVE V2

MIN VOLT: 0.70 pu
SYNCHK1 TARGET:

Self-reset
SYNCHK1 EVENTS:

Disabled
— This setting selects the source for voltage V1 (see the Notes section that follows).
— Selects the source for voltage V2, which must not be the same as used for the V1 (see Notes).
Range: 0.00 to 0.10 Hz in steps of 0.01
Range: FlexLogic operand
Range: 0.10 to 2.00 Hz in steps of 0.01
Range: 0.01 to 1.00 Hz in steps of 0.01
Range: 0.010 to 0.500 s in steps of 0.001
Range: 0.10 to 10.00 in steps of 0.01
Range: -180 to +180 degrees in steps of 1
Range: None, LV1 and DV2, DV1 and LV2, DV1 or DV2,
DV1 Xor DV2, DV1 and DV2
Range: 0.04 to 1.25 pu in steps of 0.01
Range: 0.04 to 1.25 pu in steps of 0.01
Range: 0.04 to 1.25 pu in steps of 0.01
Range: 0.04 to 1.25 pu in steps of 0.01
Range: Self-reset, Latched, Disabled
Range: Disabled, Enabled
L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
Eq. 5-27