Woodward EGCP-2 - Figure 6-1. Relationship between Voltage Bias and Generator Voltage

Manual 26174 EGCP-2 Engine Generator Control Package
Woodward 153
Most regulators, which have a voltage trim bias input, require a 0.0 Vdc voltage
bias offset. These types of regulators operate with a ±dc voltage applied to this
trim input. The voltage is then centered around zero volts offset, or zero Voltage
Bias.
Figure 6-1. Relationship Between Voltage Bias and Generator Voltage
Some regulators cannot accept a ± voltage trim input, and require a voltage bias
signal that is only positive (or negative) in value. In cases such as these the
Voltage Bias offset can be used to raise the offset of the voltage bias output to a
level, which allows more positive and less positive voltage adjustment around a
positive offset voltage.
Voltage Bias Offset will affect the rated voltage of the generator at synchronous
speed prior to the generator breaker closing. Operating the unit in a test mode
and measuring the generator voltage will show the effect the voltage bias offset
has on the generator voltage.
It is recommended that the voltage adjustment of the automatic voltage regulator
be set for the desired rated voltage of the generator with the EGCP-2 not
connected.
110% Rated Generator Voltage
90% Rated Generator Voltage
Relationship Between Voltage Bias and Generator Voltage
(Voltage Regulators which take a +/0/- voltage bias input)
0% Voltage Bias Offset (0.0 VDC)
-100% Bias
+100% Bias
Rated Generator Voltage