GE G30 Instruction Manual page 436

CONTROL ELEMENTS
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
SYNCHK1 MAX VOLT DIFF
voltage magnitude difference between the two input voltages below this value is within the permissible limit for
synchronism.
SYNCHK1 MAX ANGLE DIFF
difference between the two input voltage phasors below this value is within the permissible limit for synchronism.
SYNCHK1 MAX FREQ HYSTERESIS
condition becomes satisfied when the frequency difference becomes lower than
Synchrocheck element has operated, the frequency difference must increase above the
MAX FREQ HYSTERESIS
SYNCHK1 SYNC CLOSE
V2 vector will be arriving to synchronize (shown as V2' in the figures here) with breaker close time being taken into account
will be predicted based on the measured slip frequency so that breaker close command can be issued in advance to
ensure the synchronism at the time when the breaker is actually closed.
5
SYNCHK1 S-CLS MAX dF
disarmed when the slip frequency exceeds this setting.
SYNCHK1 S-CLS MIN dF
disarmed when the slip frequency drops below this setting.
SYNCHK1 S-CLS BRK TIME
5-262
— 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).
— Selects the maximum primary voltage difference in volts between the two sources. A primary
— Selects the maximum angular difference in degrees between the two sources. An angular
— Specifies the required hysteresis for the maximum frequency difference condition. The
sum to drop out (assuming the other two conditions, voltage and angle, remain satisfied).
— Enables the dynamic mode of synchrocheck. When it is enabled, the location of where the present
Figure 5-145: Synchrocheck plot for slip > 0 (slip = F2-F1)
Figure 5-146: Synchrocheck plot for slip < 0 (slip = F2-F1)
— Specifies the maximum slip frequency allowed in Hz in the dynamic mode. The dynamic mode is
— Specifies the minimum slip frequency allowed in Hz in the dynamic mode. The dynamic mode is
— Specifies the breaker closing time in seconds.
SYNCHK1 MAX FREQ DIFF
SYNCHK1 MAX FREQ DIFF + SYNCHK1
G30 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
. Once the