Woodward 2301D, Инструкция по установке и эксплуатации, Страница: 79 / 130

Manual 26247 2301D/2301D-EC Digital Control
Woodward 71
Load Calibration Adjustment
For this procedure, the generator must be running isochronously and not paralleled.
Start the prime mover and apply full load. With the Watch Window at
T**KW
INPUT CALIBRATION**, observe 03 Gen Output (read KW). If this reading
does not match external instrumentation, adjust calibration gain and offset until
Watch Window value matches metering. The values should match at all
intermediate points.
If values at full load (or a lower reading proportional to a load less
than 100%) cannot be obtained, and the phasing has been checked
and is correct, the current transformers are probably the wrong size.
The current-transformer output must be from 3 to 7 A (5 A nominal)
at full load.
When paralleled in isochronous mode or on an isolated bus, generator speeds
must be the same. If speed references are not equal, load sharing will not remain
proportional as the load varies. Any difference in loads between the units can be
corrected by adjusting the Load Gain. Increasing the LOAD GAIN will cause that
generator to carry less load. If stability problems occur when paralleled at a
particular load signal reading, reduce the reading by reducing the LOAD GAIN,
and reduce the load signal reading setting of all other generators in the system to
the same reading. When the load signal readings of all generators in a system
are reduced, the load sharing gain will be reduced and this may result in some
loss of load sharing sensitivity.
It may be necessary to reduce the load signal reading of each unit in the system
to as low as 3 volts in cases of extremely poor system dynamics. If your system
requires a load signal reading as low as 3 volts, consult Woodward for
suggestions for possible remedies.
Droop Adjustment
Because of the calculation available in the control, the droop percentage entered
will result in the correct speed change if the KW sensor is properly calibrated.
The droop percent is automatically corrected for load gain voltage values. The
speed trim range can be configured to stop the speed reference at 100% load, or
if a remote reference source is used its range can be set to give no load to full
load limits.
Figure 4-2. Droop Adjustment