Mitsubishi Electric FR-A800, Instruction Manual

Page: 248 / 1042

Control method Parameters
5 - 68
Keeping the motor speed constant when the load fluctuates (speed control gain)
●
Use Pr. 89 to keep the motor speed constant during variable load operation.
(This parameter is useful to make adjustments on the motor speed after replacing a conventional
model with an FR-A800 series model.)
NOTES To perform driving in a better accuracy, perform offline auto tuning, then set the online auto tun-
ing, and select Real sensorless vector control.
Under this control, rotations are more likely to be uneven than under V/F control. (This control
method is not suitable for grinder, wrapping machine, etc., which require even rotation at a low
speed.)
For FR-A820-03160(55K) or lower and FR-A840-01800(55K) or lower, the operation with a surge
voltage suppression filter (FR-ASF-H/FR-BMF-H) installed between the inverter and the motor may
reduce the output torque.
The optional sine wave filter (MT-BSL/BSC) cannot be used between the inverter and the motor.
Changing the terminal assignment using Pr. 178 to Pr. 189 (input terminal function selection) may
affect the other functions. Set parameters after confirming the function of each terminal.
Pr. Name
Initial
value
Setting
range
Description
89
G932
Speed control gain
(Advanced magnetic flux
vector)
9999
0 to 200%
Makes adjustments to keep the motor speed
constant during variable load operation under
Advanced magnetic flux vector control.
The reference value is 100%.
9999
The gain set by Pr. 71. (The gain set in accordance
with the motor.)
569
G942
Second motor speed
control gain
9999
0 to 200%
Makes adjustments to keep the second motor speed
constant during variable load operation under
Advanced magnetic flux vector control.
The reference value is 100%.
9999
The gain set by Pr. 450. (The gain set in accordance
with the motor.)
Fig. 5-7:
Adjusting speed fluctuations
I002504E
Lo
a
d
t
o
rq
u
e
Speed