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Chapter 6. Function Description (CON)
6.5.7 Droop Control
Droop control uses the drooping characteristic of the speed with respect to the torque reference. This control method
is used to prevent the saturation of the speed controller due to the difference between the speed reference and the real
speed when the inverter is used for load balancing of the multiple motors and helper roll, which is the auxiliary device of
the main roll. As shown in the figure below, the speed command is adjusted properly depending on the torque reference.
Code
LCD display
Description
Setting range
Unit
Factory setting
CON_23
Droop %
Droop Quantity
0.0 ~ 100.0
%
0.0
CON_24
Droop MinSpd
Low speed limit of
Droop control
0.0 ~ 3600.0
rpm
0.0
CON_25
Droop MinTrq
Starting torque of Droop
control %
0.0 ~ 100.0
%
0.0
If the torque reference (the output of the speed controller) becomes higher than the set Droop start torque, it
reduces the speed command and consequently, decreasing the torque reference. Speed command in the Droop control is
as in the following equation.
Speed Ref
Output
Torque
Droop Starting
Torque CON_25
Speed Ref
Droop Quantity
Droop Low Limit
CON_24