Rockwell Automation 1407-CGCM Combination Generator Control Module User Manual
Page 48
48
Rockwell Automation Publication 1407-UM001G-EN-P - April 2013
Chapter 3
CGCM Unit Operation
Reactive Power Regulation Mode (VAR)
In VAR mode, the CGCM unit controls field excitation current output to
maintain the commanded reactive power setpoint. The CGCM unit uses the
measured generator voltages and currents to calculate reactive power. The VAR
feedback loop includes adjustable proportional and integral gains. To activate
VAR mode:
• the metering CTs and VTs must be properly connected and configured.
• the VAR mode gains must be set.
• the desired reactive power setpoint must be written to the VARSetpt tag.
• excitation enabled (tag SoftwareExcEn = 1).
• remote Excitation Enable On (discrete input).
• the CGCM unit must be in AVR mode (tag AVR_FCR_Select = 0).
• droop must be enabled (V_DroopEn tag = 1).
• droop must be selected (Droop_CCC_Select tag = 0).
• automatic reactive power control must be enabled (tag PF_VAR_En = 1).
• VAR control must be selected (tag PF_VAR_Select = 1).
Soft Start Mode
CGCM unit Soft Start mode provides for an orderly build-up of generator
voltage from residual to the voltage setpoint in the desired time with minimal
overshoot. When the system is in Soft Start mode, the CGCM unit adjusts the
voltage reference based on the Soft Start Initial Voltage and Soft Start Time.
The
illustration is a graph for the voltage reference
showing soft start initial voltage at 30%, soft start time at 8 seconds.
Figure 29 - Soft Start Voltage Reference