ABB ACS 600 Supplement To Firmware Manual page 28

Chapter 4 – Parameters
60.04 WINDOW WIDTH
60.05 WINDOW WIDTH
60.06 DROOP RATE
4-10
This parameter value is considered only if window control is on. The
POS allowed setting range is from 0 to 1500 rpm.
The speed controller input is kept at zero until the speed error exceeds
the value WINDOW WIDTH POS. See Figure 4-2.
This parameter value is considered only if window control is on. The
NEG allowed setting range is from 0 to 1500 rpm.
The speed controller input is kept at zero until the absolute value of the
negative speed error exceeds WINDOW WIDTH NEG. See Figure 4-2.
This parameter value needs to be changed only if both the Master and
the Follower are speed-controlled:
• External control location 1 (EXT1) is selected (see Parameter
11.02 EXT 1/EXT 2 SELECT, or
• External control location 2 (EXT2) is selected (see Parameter
11.02 EXT 1/EXT 2 SELECT) and Parameter
60.02 TORQUE SELECTOR is set to SPEED.
CAUTION! Follower speed control or drooping should not be used if
the motor shafts of the Master and the Follower are coupled fixedly by a
mechanical construction (gearing, chain etc.).
Drooping slightly decreases the drive speed as the drive load increases
in order to prevent uneven load division between the Master and
Follower drives. The correct droop rate for each process needs to be
found out case by case in practice. Drooping is typically used on the
Follower(s) only, but a droop rate can also be set for the Master.
The droop rate is set as % of drive maximum speed. The actual speed
decrease in a certain operating point depends on the droop rate setting
and the internal torque reference of the drive (speed controller output).
ACS 600 Master/Follower Application Macro