Basler Electric BE1-11g - Manual (Page 165)

9424200994 Rev N 153
Frequency Correction
Generator frequency correction is defined by the Slip Frequency setting and further refined by the Breaker
Close Angle setting (available in PLL mode only). The Slip Frequency setting establishes the maximum
allowable deviation of the generator speed (frequency) from the bus frequency. The Minimum Slip and
Maximum Slip settings are used to calculate the slip frequency error and to provide slip frequency control
while in phase lock synchronization. If the slip frequency magnitude is above the Maximum Slip setting,
the error is set equal to the Max Error in the opposite polarity. If the slip frequency magnitude is below the
Minimum Slip setting, the slip frequency error is zero (0). When it is between the two settings, the error is
calculated internally by the BE1-11g. Slip frequency error is shown in Figure 95.
Figure 95. Slip Frequency Error
To minimize the impact on the bus during synchronization, the Frequency Source > Frequency
Destination setting can be enabled to force the generator frequency to exceed the bus frequency at the
moment of breaker closure. If this is the case, the BE1-11g will drive the generator frequency higher than
the bus frequency before closing the breaker.
The Breaker Close Angle setting (available in Phase Lock Loop mode only) defines the maximum
allowable phase angle difference between the generator and the bus. For breaker closure to be
considered in PLL mode, the slip angle must be less than or equal to the breaker close angle.
The breaker close angle is not used in Anticipatory mode. Instead, the breaker close time and metered
slip frequency are used to calculate an “advance angle”. The angle is considered in sync when the slip
angle equals the advance angle.
Voltage Correction
Generator voltage correction is defined by the Voltage Difference setting. This setting is expressed as a
percentage difference between the generator nominal voltage and bus nominal voltage. If the Voltage
Source > Voltage Destination setting is enabled, the BE1-11g will drive the generator voltage to at least
0.5% greater than the bus voltage.
Synchronization Failure
The Sync Fail Activation Delay and Breaker Close Attempts settings establish the maximum duration in
which synchronizing can occur. If the 25A Synchronizer element issues a breaker close, and the breaker
fails to close within this time, the logic increments the Breaker Close Attempts counter. If the number of
breaker close attempts has exceeded the Breaker Close Attempts setting, then generator synchronization
is aborted. At this time, the Sync Fail logic output pulses high. Note that if either bus becomes unstable,
the synchronizer timers are reset. The breaker close attempt counter retains its value.
Voltage Monitoring
The Volt Monitor logic output is provided for conditions where the bus and/or the line are dead. In
BESTlogicPlus, the Volt Monitor logic output can be connected to other logic elements to annunciate the
condition or control other elements in logic. The Volt Monitor logic output will only affect the 25A when
connected in logic. A live condition for either the phase voltage or auxiliary voltage is determined when
the measured voltage on the respective input is equal to or above the live voltage threshold established
by the Live Voltage setting. A dead condition for either phase voltage or auxiliary voltage is determined
when the measured voltage on the respective input is equal to or below the dead voltage threshold
established by the Dead Voltage setting. The Dropout Delay setting provides hysteresis for the Volt
Monitor logic output.
Slip Error
= Max (-)
Slip Error
= Max (+)
Slip Error = 0
P0064-49
BE1-11g Synchronizer (25A)