*
For additional assistance, please contact Toshiba Adjustable Speed Drive Marketing Dept. at (800) 872-
2192
71
A drive with MAXIMUM OUTPUT FREQUENCY set to 80 Hz and DROOPING CONTROL AMOUNT
set to 10% will output the following frequencies at the following torque currents:
Commanded
Frequency (Hz)
Torque
Current (%)
Output
Frequency (Hz)
60 120 50.4
60 100 52
60 80 53.6
60 60 55.2
Notes applicable while using drooping control
PID cannot be used
Do not use “S” accel/decel pattern
Drive output frequency may go lower than Item 7, LOWER LIMIT FREQUENCY
The acceleration/deceleration complete signal may not occur
Operation in jump frequency bandwidths may occur
START-UP FREQUENCY and RUN FREQUENCY are still valid
Stall overrides Droop
Contact drive marketing for information on how to change the Droop reaction time.
Contact drive marketing for inforamtion on how to increase droop amount larger than 10%.
Contact drive marketing for information concerning positive droop.
Common Frequency Reference
The drives used in a drooping system share a frequency reference; use the G3’s RS485
master/follower
board (see application guideline) or provide identical references.
Procedure
¾
Make sure that the acceleration/deceleration times in the drives are the same.
¾
If mechanical reductions between motor and final driven equipment are not the same for the motors,
adjust bias/gain of drives appropriately.
¾
Display torque current (in %) in one of both drives’ monitors (set Items 289,290,291, or 292 set to
“6”).
¾
Enable drooping control on all drives.
¾
Operate system loaded and adjust DROOPING CONTROL AMOUNT so that the inverters’ torque
currents are equal.
