Mitsubishi Electric FR-A820-00046 (0.4K), Instruction Manual

Page: 307 / 1218

Parameters Speed control under Real sensorless vector control, vector control, PM sensorless vector control
FR-A800 5 - 105
Execution procedure for easy gain tuning (Pr. 819= "1" Load inertia ratio automatic calculation)
Easy gain tuning (load inertia ratio automatic calculation) is only valid in the speed control and posi-
tion control modes of vector control. It is invalid under torque control, V/F control, Advanced mag-
netic flux vector control, Real sensorless vector control, and PM sensorless vector control.
Set the response level in Pr. 818 "Easy gain tuning response level setting".
Increasing the value will improve trackability to the command, but too high value will generate
vibration. The following figure shows the relationship between the setting and the response level.
The load inertia ratio is calculated during acceleration/deceleration, and the gain for each control
is set automatically from this value and the value of Pr. 818 "Easy gain tuning response level
setting". Pr. 880 "Load inertia ratio" is used as the initial value of the load inertia ratio when
performing tuning. During tuning, the calculated value is set in Pr. 880.
The calculation of the load inertia ratio may take excessive time or otherwise not be performed
properly if the following conditions are not satisfied.
– The time in acceleration/deceleration driving until 1500 r/min is reached in 5 s or less.
– The rotation speed in driving is 150 r/min or higher.
– The acceleration/deceleration torque is 10 % or higher.
– No sudden external disturbances during acceleration/deceleration.
– The load inertia ratio is about 30-fold or lower.
– No gear backlash or belt sagging.
Press FWD or REV key to calculate the continuous load inertia ratio, or calculate the gain.
(The operation command during External operation is the STF or STR signal.)
Pr. 818 setting 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Response level
Slow
response Middle
response
Fast
response
Guideline of mechanical
resonance frequency [Hz]
8 10 12 15 18 22 28 34 42 52 64 79 98 122 150
Inverter application
I001482E
Tab. 5-34: Response level setting
Large
conveyor
General machine
tool, conveyor
Arm robot
Precision
machine tool