Mitsubishi Electric FR-A700 Technical Manual page 257

2.9.5 Torque bias [Pr. 840 to 848]
This function accelerates the rise of the torque at a start. Adjust the torque at a motor start using the contact signals or analog
signals. Valid only during vector control.
[Pr. ] Name
Torque bias selection
840
841
Torque bias 1
842
Torque bias 2
843
Torque bias 3
844
Torque bias filter
Torque bias operation time
845
Torque bias balance
846
compensation
Fall-time torque bias
847
terminal 1 bias
Fall-time torque bias
848
terminal 1 gain
* When FR-A7AZ is installed, torque bias amount setting from terminal 6 is also available.
(1) Block diagram
Speed command
Torque bias selection 1
Torque bias selection 2
(2) Torque bias amount setting by contact input
(X42, X43 signal) [Pr. 840 = 0, Pr. 841 to 843]
Select the torque bias amount in the table below
according to the combination of contact signals.
Set 42 in [Pr. 178 to 189 Input terminal function
selection] for the terminal used for X42 signal input
and set 43 for the terminal used for X43 signal input
to assign functions.
X42 Signal X43 Signal
OFF OFF
ON OFF
OFF ON
ON ON
A700
(A700)
Initial Value Setting Range
0
1
9999
2
3
9999
600 to 999%
9999 1000 to 1400%
9999
0 to 5s
9999
9999
0 to 5s
9999
9999
0 to 10V
9999
9999
0 to 400%
9999
9999
0 to 400%
9999
9999
Speed
Speed command
+
control
P gain
-
Internal parameters
X42
[Pr. 841]
[Pr. 842]
X43
[Pr. 843]
SD +
-
[Pr. 846]
Torque Bias Amount
0
[Pr. 841]
[Pr. 842]
[Pr. 843]
Set the contact signal (X42, X43) based-torque bias amount
using [Pr. 841 to 843].
Set the terminal 1-based torque bias amount as desired in [C16 to
C19]. * (in the case a cage goes up when a motor runs reversely)
Set the terminal 1-based torque bias amount as desired in [C16 to
C19]. * (in the case a cage goes up when a motor runs forward)
The terminal 1-based torque bias amount can be set
automatically in [C16 to C19, Pr. 846] according to the load. *
Without torque bias, rated torque 100%
Negative torque bias amount (
Positive torque bias amount (0% to 400%)
Without torque bias setting
Time until torque rises.
Same operation as when 0s is set.
Time for maintaining torque equivalent to the torque bias amount.
Same operation as when 0s is set.
Set the voltage under balanced load.
Same operation as when 0V is set.
Set the bias value of the torque command.
Same as at a rise time [C16, C17 (Pr. 919)].
Set the gain value of the torque command.
Same as at a rise time [C18, C19 (Pr. 919)].
+ +
+ +
Speed
control
integral time
0
Integration cleared to 0
[Pr. 845]
[ Pr. 840 = 0 ]
C16, C17
CW Cage
[Pr. 919]
C18, C19
CW > Cage
[Pr. 920]
The setting 1000 of [Pr. 841 to 843] is the torque bias
amount 0%.
Namely, on the assumption that the setting 1000 is
the center value, (setting-1000) is the torque bias
amount.
Therefore, setting 600 to 1400 corresponds to -400%
to +400% torque bias amount.
[Example] When [Pr. 841 = 1025] ... 25%
When [Pr. 842 = 975] ... -25%
When [Pr. 843 = 925] ... -75%
291
PARAMETER
Description
- -
400% to 1%)
Torque
IM
control
Encoder
[Pr. 840 = 1, 2, 3]
[Pr. 826]
Torque setting filter 1
Terminal 1 or
Load
Terminal 6 detector
(FR-A7AZ)
2
CW
Cage