Mitsubishi Electric FR-A820-00046 Instruction Manual page 307

Parameters Speed control under Real sensorless vector control, vector control, PM sensorless vector control
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.
Pr. 818 setting
Response level
Guideline of mechanical
resonance frequency [Hz]
Inverter application
Tab. 5-34:
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.)
FR-A800
1 2 3
Slow
response
8 10 12
Response level setting
4 5 6 7 8
Middle
response
15 18 22 28 34
Large
General machine
conveyor
tool, conveyor
Arm robot
9 10 11 12 13
42 52 64 79 98
Precision
machine tool
14 15
Fast
response
122 150
I001482E
5 - 105