Kohler EKOZD Series Service page 220

Sync Frequency Window
The Frequency Window is the maximum difference in
output frequency between the bus and the generator at
which the frequency is considered to be matched. The
generator frequency can be above or below the bus
frequency, but must be within the Sync Frequency
Window of the bus to be considered as matched.
There is a slight delay in the activation of the paralleling
breaker (typically between 50 and 100ms). If the
frequency difference is too high, the breaker may close
out of phase, even though it was in phase when the
close signal was activated.
Note: The frequency matching controller is active until
the generator frequency is within 1/10 of the
frequency window of the bus frequency. Once
within this window, the frequency matching
controller is de-activated and the phase matching
controller is activated. The phase matching
controller is de-activated and the frequency
matching controller is activated if the frequency of
the generator differs by more than the Frequency
Match Window from the bus frequency.
Setting the frequency window too wide may make it
difficult for the phase matching controller to work correctly.
Range: 0.1 – 5.0Hz
Default: 2.0Hz
Phase Match Window
The Phase Angle Window defines the threshold that the
phase angle between the L1-L2 generator voltage and the
L1-L2 paralleling bus voltage must remain below for the
phase of the generator to be considered to be matched
with the paralleling bus. The generator voltage may either
lead or lag the bus voltage, but must be within the Phase
Match Window to be considered to be matched.
Large phase angle differences between the generator
and the paralleling bus when the paralleling breaker
closes will result in large current spikes as the alternator
field is forced to align between the generators. Phase
Match Windows above 15_ are not recommended.
Range: 1.0_ – 20.0_
Default: 5.0_
Dwell Time
The Dwell Time is the time duration that the
synchronizer requires the voltage, frequency, rotation
and phase of the generator to match that of the
paralleling bus before it will signal the paralleling
breaker to close.
220 Section 12 Paralleling System Information
Setting the dwell time too short may cause the breaker to
close when the generator frequency does not match the
bus frequency very closely (resulting in a small real
power discrepancy when the breaker first closes). Short
dwell times are occasionally required in applications
where the engine frequency regulation is loose (such as
spark-ignited engines).
Setting the dwell time too long will only delay breaker
closure and will not improve the real power discrepancy
when the breaker closes. Dwell times longer than
2 seconds are only required in very special applications.
Range: 0.1 – 30.0 sec
Default: 0.3 sec
Voltage Match Proportional Gain
The Voltage Match Proportional Gain adjusts the
Voltage Bias by an amount that is directly related to the
difference between the average generator line voltage
and the average bus line voltage. The voltage bias is
adjusted in the direction that should decrease the
difference between the generator and the paralleling
bus.
Range: 0.01 – 100.00
Default: 1.00
Voltage Match Integral Gain
The Voltage Match Integral Gain adjusts the Voltage
Bias at a rate that is related to the difference between the
average generator line voltage and the average bus line
voltage. The voltage bias is adjusted in the direction that
should decrease the difference between the generator
and the paralleling bus.
Range: 0.01 – 100.00
Default: 1.00
Voltage Match Derivative Gain
The Voltage Match Derivative Gain adjusts the Voltage
Bias by an amount that is related to the rate of change of
the difference between the average generator line
voltage and the average bus line voltage. The voltage
bias is adjusted in the direction that should decrease the
rate of change of the difference between the generator
and the paralleling bus.
Note: This gain is set very low from the factory, but may
be needed to track the bus voltage if the load on
the bus is changing often.
Range: 0.01 – 100.00
Default: 1.00
TP-6953 7/19