EGCP-2 Engine Generator Control Package Manual 26174
128 Woodward
VAR Control
The VAR control adjusts generator voltage to maintain a constant reactive power
(kVAR) load on the generator throughout the kW operating range while the
generator is in parallel with the mains. This assures sufficient excitation of the
generator field under all load conditions. A set point is provided to set the desired
VARs. The VAR control function may be enabled with VAR/PF Control mode
selection set point. The kVAR reference may be changed once the generator is
in parallel with the mains by issuing a raise/lower voltage contact input to the
EGCP-2. Raising the kVAR reference will raise the voltage bias output to the
voltage regulator, which will cause VARs to be exported to the Mains. Lowering
the VAR reference will decrease the voltage bias output to the regulator that will
cause VARs to be absorbed from the utility.
Power Factor Control
The power factor control adjusts generator voltage to maintain a constant power
angle throughout the kW operating range while the generator is in parallel with
the mains. A set point is provided for the desired power factor reference. The
power factor control function may be enabled with the VAR/PF Control mode
selection set point. The PF reference may be changed once the generator is in
parallel with the mains by issuing a raise/lower voltage contact input to the
EGCP-2. Raising the PF reference will raise the voltage bias output to the
voltage regulator, which will cause the PF to move in an increasing lagging PF
angle. Lowering the PF reference will decrease the voltage bias output to the
regulator that will cause PF to move in an increasing Leading PF angle.
Power Factor Sharing
When either VAR or Power Factor Control is selected, and the EGCP-2 control is
operating in isochronous load sharing mode, power factor sharing is
automatically selected. Power factor sharing adjusts the voltage regulators so
that all generators carry the same proportion of reactive load by balancing the
power factor on all units. A voltage reference set point is provided to define the
system operating voltage. Multiple EGCP-2 controls operating in Power Factor
Sharing mode will trim their respective voltages to share the reactive load on the
isolated bus, and operate around the voltage reference setting.
Synchronizer Description
Synchronization, as normally applied to the generation of electricity, is the
matching of the output voltage waveform of one alternating current electrical
generator with the voltage waveform of another alternating current electrical
system. For the two systems to be synchronized and connected in parallel, five
conditions must be considered:
the number of phases in each system
the direction of rotation of the phases
the voltage amplitudes of the two systems
the frequencies of the two systems
the phase angle of the voltage of the two systems
The first two conditions are determined when the equipment is specified,
installed, and wired. The synchronizer matches the remaining conditions
(voltage, frequency, and phase) before the paralleling breakers are closed.
Functional Description
This section describes how generator and bus matching occurs and how all
conditions are verified by the synchronizer functions.
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