Allen-Bradley 1407-CGCM, User Manual, Page: 91 / 252

Rockwell Automation Publication 1407-UM001H-EN-P - November 2014
CGCM Unit Configuration #HAPTER
Under-excitation Limiting
The UEL gains determine the response of the UEL control loop for the voltage
regulation function when UEL is active. These settings can be adjusted during
system startup.
Please refer to Chapter 5 for more information on tuning the UEL control gains.
•
Integral Gain Ki - Sets the integral gain. If the time to reach steady state is
too long, increase Ki. The tag
UEL_Ki in the Unscheduled Write table
stores this parameter.
•
Overall Gain Kg - Sets the overall gain, which determines the characteristic
of the dynamic response when UEL is active. If the transient response has
too much overshoot, decrease Kg. If the transient response is too slow, with
little or no overshoot, then increase Kg. The tag
UEL_Kg in the
Unscheduled Write table stores this parameter.
Other Gains
The remaining three gains are stored in the Configuration table and can only be
written to the CGCM unit when excitation is disabled.
Please refer to Chapter 6 for more information.
•
AVR/FCR Control Auxiliary Gain - Sets the influence of the auxiliary
input on the AVR/FCR operating setpoint. The units are percent of rated
generator voltage or excitation field current, as applicable, per auxiliary
input volt. The tag
AVR_FCRAuxGain in the Configuration table stores
this parameter.
•
PF/VAR Auxiliary Gain - Sets the influence of the auxiliary input on the
VAR/PF operating setpoint. The units for the var controller are percent of
rated generator KVA. For PF control, the units are 0.01 PF per volt. A
setting of 5 results in the regulated PF being changed by 0.05 for each volt
applied to the auxiliary input. The tag
PF_VARAuxGain in the
Configuration table stores this parameter.
•
Cross-current Gain - sets the gain of the cross-current input. The measured
cross-current value is multiplied by this setting. This setting determines the
change in voltage setpoint expressed in percent of rated voltage for a
change in kVARs equal to the rated generator kVA. This parameter adjusts
the characteristic of VAR sharing between machines connected in the
cross-current compensation method of VAR sharing. A setting of 5, for
example, results in the voltage setpoint being changed by 5% of rated
voltage for a change in kVARs equal to the rated kVA. The tag
CrossCurrentGain in the Configuration table stores this parameter.
Related Parameters
•
GenRated_V
•
GenRated_I
•
GenRatedExcI