Rockwell Automation 1407-CGCM Combination Generator Control Module - Manual (Page 190)

190 Rockwell Automation Publication 1407-UM001G-EN-P - April 2013
Appendix B CGCM Unit Math Models
Soft Start Control The soft start control function is provided to cause orderly build-up of terminal
voltage from the residual voltage to the rated voltage in desired time with
minimal overshoot. In CGCM units, the fast dynamic response is used while the
voltage reference is adjusted based on the elapsed time. When the system is under
start-up condition, the voltage reference is adjusted by the amount calculated
based on two programmable parameters, initial soft start voltage level (V
O
) and
desired time (T
SS
) to build up to the rated voltage. Its mathematical model is
shown in Soft Start Control. The soft start gain (K
SS
) is calculated by using this
formula.
K
SS
= (V
REF
- V
O
) / T
SS
Figure 68 - Soft Start Control
Time From Start
AVR
Summing
Point